汽车制动外文翻译

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中英文文献翻译-汽车制动系统

附录附录ABraking system function is to make the car driving in accordance with the requirements of the pilot required even slow down park; They offend car has in various road conditions (including in the slope stability) in car; Make the downhill cars speed to be stable.For car up the role of brake is only in the car and role with the direction of the car driving direction opposite forces, and the size of these forces are random, do not control, so cars must be installed on a series of special equipment to achieve the function.Automobile brake system is to point to to ensure that the car in technology, improve the safe driving car average speed, etc., and the admiration installed in the car brake special brake institutions. In general automobile brake system including crane brake system and parking brake two sets of independent device. One crane brake device is a driver with feet to manipulate, and it said the foot brake. Parking brake device is a pilot with the hand, so it says of the manipulation of the hand brake. The function of the crane brake system is to make the car slow down or running in the shortest distance parking within. And parking brake function is to make had stopped the car on the road all keep still. But, sometimes, in an emergency, two braking device can be used at the same time and increase the effect of auto brake. Some special purpose of cars and often in the mountains cars, long and frequently brake will lead to crane brake system overheating, so in these cars often add all sorts of different types of auxiliary braking equipment, so as to speed up the hill stability.According to the braking energy situation, brake system can also be divided into human brake system, power brake system, and servo brake system, three. Human brake system to the driver's physical strength as braking energy; Power brake system engine power to the transformation of the air pressure or hydraulic braking energy as; And servo brake system is the most human and engine power as a brake energy. In addition, according to the braking energy transfer mode, brake system and can be divided into mechanical and hydraulic, pneumatic type and assolenoid style wait until a few kinds.In the types of brake system, the brake is car brake system to produce stop the traffic movement or movement trend components. Force At present, the kind used by car is friction brakes brake, also is to prevent the braking torque motor sports from fixed components and rotation of the friction between the work surface.附录B制动系统作用是使行驶中的汽车按照驾驶员的要求进行强制减速甚至停车；使已停驶的汽车在各种道路条件下(包括在坡道上)稳定驻车；使下坡行驶的汽车速度保持稳定。

离合器汽车制动系统外文文献翻译、中英文翻译、外文翻译

3.1 ClutchThe engine produces the power to drive the vehicle. The drive line or drive train transfers the power of the engine to the wheels. The drive train consists of the parts from the back of the fl ywheel to the wheels. These parts include the clutch, the transmission, the drive shaft, and the final drive assembly.The clutch which includes the flywheel, clutch disc, pressure plate, springs, pressure plate cover and the linkage necessary to operate the clutch is a rotating mechanism between the engine and the transmission. It operates through friction which comes from contact between the parts. That is the reason why the clutch is called a friction mechanism. After engagement, the clutch must continue to transmit all engine torque to transmission depending on the friction without slippage. The clutch is also used to disengage the engine from the drive train whenever the gears in the transmission are being shifted from gear ratio to another.To start the engine or shift the gears, the driver has to depr ess the clutch pedal with the purpose of disengagement the transmission from the engine. At that time, the driven members connected to the transmission input shaft are either stationary or rotating at a speed that is slower of faster than the driving membe rs connected to engine crankshaft. There is no spring pressure on the clutch assembly parts. So there is no friction between the driving members and driven members. As the driver let’s loose the clutch pedal, spring pressure increase on the clutch parts. Friction between the parts also increases. The pressure exerted by the springs on the driven members is controlled by the driver through the clutch pedal and linkage. The positive engagement of the driving and driven members is made possible the friction be tween the surfaces of the members. When full spring pressure is applied, the speed of the driving and driven members should be the same. At themoment, the clutch must act as a coupling device and transmit all engine power to the transmission, without slipping.However, the transmission should be engaged to the engine graduall y in order to operate the car smoothly and minimize tensional shock on the drive train because an engine at idle just develop little power. Otherwise, the driving members are connecte d with the driven members too quickly and the engine would be stalled.The fl ywheel is a major part of the clutch. The flywheel mounts to the engine’s crankshaft and transmits engine torque to the clutch assembly. The flywheel, when coupled with the clutc h disc and pressure plate makes and breaks the flow of power the engine to the transmission.The flywheel provides a mounting location for the clutch assembly as well. When the clutch is applied, the fl ywheel transfers engine torque to the clutch disc. Because of its weight, the fl ywheel helps to smooth engine operation. The flywheel also has a large ring gear at its outer edge, which engages with a pinion gear on the starter motor during engine cranking.The clutch disc fits between the fl ywheel and the pressure plate. The clutch disc has a splinted hub that fits over splints on the transmission input shaft. A splinted hub has grooves that match splints on the shaft. These splints fit in the grooves. Thus, the two parts held together. However, back – and – forth movement of the disc on the shaft is possible. Attached to the input shaft, the disc turns at the speed of the shaft.The clutch pressure plate is generall y made of cast iron. It is round and about the same diameter as the clutch disc. One side of the pressure plate is machined smooth. This side will press the clutch disc facing are against the flywheel. The outer side has shapes to facilitate attachment of spring and release mechanism. The two primary t ypes of pressure plate assemblies are coil sp ring assembly and diaphragm spring.In a coil spring clutch the pressure plate is backed by a number of coil springs and housed with them in a pressed –steed cover bolted to the flywheel. The spring pushes against the cover. Neither the driven plate nor the pressure plate is connected rigidl y to the flywheel and both can move either towards it o away. When the clutch pedal is depressed a thrust pad riding on a carbon or ball thrust bearing is forced towards the flywheel. Levers pivoted so that they engage with the thrust pad at one end and the pressure plate tat the other end pull the pressure plate back against its springs. This releases pressure on the driven plate disconnecting the gearbox from the engine.Diaphragm spring pressure plate assemblies are widely used in most modern cars. The diaphragm spring is a single thin sheet of metal which yields when pressure is applied to it. When pressure is removed the metal spring back to its original shape. The center portion of the diaphragm spring is slit int o numerous fingers that act as release levers. When the clutch assembly rotates with the engine these weights are flung outwards by centrifugal plate and cause the levers to press against the pressure plate. During disengagement of the clutch the fingers are moved forward by the release bearing. The spring pivots over the fulcrum ring and its outer rim moves away from the flywheel. The retracting spring pulls the pressure plate away from the clutch plate thus disengaging the clutch.When engaged the release bearing and the fingers of the diaphragm spring move towards the transmission. As the diaphragm pivots over the pivot ring its outer rim forces the pressure plate against the clutch disc so that the clutch plate is engaged to flywheel.The advantages of a diaphragm t ype pressure plate assembl y are its compactness, lower weight, fewer moving parts, less effort to engage, reduces rotational imbalance by providing a balanced force around the pressure plate and less chances of clutch slippage.The clutch pedal is connected to the disengagement mechanismeither by a cable or, more commonly, by a hydraulic s ystem. Either way, pushing the pedal down operates the disengagement mechanism which puts pressure on the fingers of the clutch diaphragm via a release bearing and causes the diaphragm to release the clutch plate. With a hydraulic mechanism, the clutch pedal arm operates a piston in the clutch master cylinder. This forces hydraulic fluid through a pipe to the cutch release cylinder where another operates the c lutch disengagement mechanism by a cable.The other parts including the clutch fork, release bearing, bell –housing, bell housing cover, and pilot bushing are needed to couple and uncouple the transmission. The clutch fork, which connects to the linkage, actually operates the clutch. The release bearing fits between the clutch fork and the pressure plate assembly. The bell housing covers the clutch assembly. The bell housing cover fastens to the bottom of the bell housing. This removable cover allows a me chanic to inspect the clutch without removing the transmission and bell housing. A pilot bushing fits into the back of the crankshaft and holds the transmission input shaft.3.2 Brake SystemThe breaking system is the most important system in cars. If the brakes fail, the result can be disastrous. Brakes are actually energy conversion devices, which convert the kinetic energy (momentum) of the vehicle into thermal (heat). When stepping on the brakes, the driver commands a stopping force ten times as powerfu l as the force that puts the car in motion. The braking system can exert thousands of pounds of pressure on each of the four brakes.The brake s ystem is composed of the following basic components: the “master cylinder” which is located under the hood, and is directl yconnected to the brake pedal, converts driver foot’s mechanical pressure into hydraulic pressure. Steel “brake lines” and flexible “brake hoses” connect the master cylinder to the “slave cylinders” located at each wheel. Brake fluid, speciall y designed to work in extreme condition, fills the system. “Shoes” and “Pads” are pushed by the salve cylinders to contact the “drum” and “rotors” thus causing drag, which (hopefull y) slows the car.The typical brake system consists of disk brakes in front and either disk or drum brakes in the rear connected by a system of tubes and hoses that link the brake at each wheel to the master cylinder.Stepping on the brake pedal, a plunger is actually been pushing against in the master cylinder which forces hydr aulic oil (brake fluid) through a series of tubes and hoses to the braking unit at each wheel. Since hydraulic fluid (or any fluid for that matter) cannot be compressed, pushing fluid through a pipe is just like pushing a steel bar through pipe. Unlike a s teel bar, however, fluid can be directed through many twists and turns on its way to its destination, arriving with the exact same motion and pressure that it started with. It is very important that the fluid is pure liquid and that there is no air bubbles in it. Air can compress which causes sponginess to the pedal and severely reduced braking efficiency. If air is suspected, then the system must be bled to remove the air. There are “bleeder screws” at each wheel and caliper for this purpose.On disk brakes, the fluid from the master cylinder is forced into a caliper where it pressure against a piston. The piton, in-turn, squeezes two brake pads against the disk (rotor) which is attached to the wheel, forcing it to slow down or stop. This process is simila r to the wheel, causing the wheel to stop. In either case, the friction surface of the pads on a disk brake system, on the shoes on a drum brake convert the forward motion of the vehicle into heat. Heat is what causes the friction surfaces (lining) of the pads and shoes to eventually wear out andrequire replacement.Brake fluid is special oil that has specifics properties. It is designed to withstand cold temperatures without thickening as well as very high temperatures without boiling. (If the brake flui d should boil, it will cause you to have a spongy pedal and the car will be hard to stop).The brake fluid reservoir is on top of the master cylinder. Most cars today have a transparent reservoir so that you can see the level without opening the cover. Th e brake fluid lever will drop slightl y as the brake pads wear. This is a normal condition and no cause for concern. If the lever drops noticeabl y over a short period of time or goes down to about two thirds full, have your brakes checked as soon as possible. Keep the reservoir covered expect for the amount of time you need to fill it and never leave a can of brake fluid uncovered. Brake fluid must maintain a very high boiling point. Exposure to air will cause the fluid to absorb moisture which will lower th at boiling point.The brake fluid travels from the master cylinder to the wheels through a series of steel tubes and reinforced rubber hoses. Rubber hoses are onl y used in places that require flexibility, such as at the front wheels, which move up and dow n as well as steer. The rest of the system uses non-corrosive seamless steel tubing with special fittings at attachment points. If a steel line requires a repair, the best procedure is to replace the complete line. If this is nit practical, a line can be repaired using special splice fittings that are made for brake system repair. You must never use brass “compression” fittings or copper tubing repair a brake system. They are dangerous and illegal.3.2.1 Other Components in the Hydraulic System Proportioning Valve or Equalizer ValveThese valves are mounted between the master cylinder and the rear wheels. They are designed to adjust the pressure between the front and the rear brakes depending on how hard you are stopping. The shorter you stop, the mor e of the vehicle’s weight is transferred to the front wheels, in some cases, causing the rear to lift and the front to dive. These valves are designed to direct more pressure to the front and less pressure to the harder you stop. This minimizes the chance of premature lockup at the rear wheels.Pressure Differential ValveThis valve is usually mounted just below the master and is responsible for turning the brake warning light on when it detects a malfunction. It measures the pressure from the two sections of the master cylinder and compares them. Since it is mounted ahead of the proportioning or equalizer valve, the two pressures it detects should be equal. If it detects a difference, it means that there is probably a brake fluid leak somewhere in the syst em.3．1 离合器发动机产生动力来驱动汽车，它通过传动系把动力传递到车轮上，传动系包含从飞轮到车轮的所有零件。

汽车制动器论文中英文对照资料外文翻译文献

中英文对照资料外文翻译文献Automobile Brake SystemThe braking system is the most important system in cars. If the brakes fail, the result can be disastrous. Brakes are actually energy conversion devices, which convert the kinetic energy (momentum) of the vehicle into thermal energy (heat).When stepping on the brakes, the driver commands a stopping force ten times as powerful as the force that puts the car in motion. The braking system can exert thousands of pounds of pressure on each of the four brakes.Two complete independent braking systems are used on the car. They are the service brake and the parking brake.The service brake acts to slow, stop, or hold the vehicle during normal driving. They are foot-operated by the driver depressing and releasing the brake pedal. The primary purpose of the brake is to hold the vehicle stationary while it is unattended. The parking brake is mechanically operated by when a separate parking brake foot pedal or hand lever is set.The brake system is composed of the following basic components: the “master cylinder” which is located under the hood, and is directly connected tothe brake pedal, converts driver foot’s mechanical pressure into hydraulic pressure. Steel “brake lines” and flexible “brake hoses” connect the master cylin der to the “slave cylinders” located at each wheel. Brake fluid, specially designed to work in extreme conditions, fills the system. “Shoes” and “pads” are pushed by the slave cylinders to contact the “drums” and “rotors” thus causing drag, which (hopefully) slows the car.The typical brake system consists of disk brakes in front and either disk or drum brakes in the rear connected by a system of tubes and hoses that link the brake at each wheel to the master cylinder (Figure).Basically, all car brakes are friction brakes. When the driver applies the brake, the control device forces brake shoes, or pads, against the rotating brake drum or disks at wheel. Friction between the shoes or pads and the drums or disks then slows or stops the wheel so that the car is braked.In most modern brake systems (see Figure 15.1), there is a fluid-filled cylinder, called master cylinder, which contains two separate sections, there is a piston in each section and both pistons are connected to a brake pedal in the driver’s com partment. When the brake is pushed down, brake fluid is sent from the master cylinder to the wheels.At the wheels, the fluid pushes shoes, or pads, against revolving drums or disks. The friction between the stationary shoes, or pads, and the revolving drums or disks slows and stops them. This slows or stops the revolving wheels, which, in turn, slow or stop the car.The brake fluid reservoir is on top of the master cylinder. Most cars today have a transparent r reservoir so that you can see the level without opening the cover. The brake fluid level will drop slightly as the brake pads wear. This is a normal condition and no cause for concern. If the level drops noticeably over ashort period of time or goes down to about two thirds full, have your brakes checked as soon as possible. Keep the reservoir covered except for the amount of time you need to fill it and never leave a cam of brake fluid uncovered. Brake fluid must maintain a very high boiling point. Exposure to air will cause the fluid to absorb moisture which will lower that boiling point.The brake fluid travels from the master cylinder to the wheels through a series of steel tubes and reinforced rubber hoses. Rubber hoses are only used in places that require flexibility, such as at the front wheels, which move up and down as well as steer. The rest of the system uses non-corrosive seamless steel tubing with special fittings at all attachment points. If a steel line requires a repair, the best procedure is to replace the compete line. If this is not practical, a line can be repaired using special splice fittings that are made for brake system repair. Y ou must never use copper tubing to repair a brake system. They are dangerous and illegal.Drum brakes, it consists of the brake drum, an expander, pull back springs, a stationary back plate, two shoes with friction linings, and anchor pins. The stationary back plate is secured to the flange of the axle housing or to the steering knuckle. The brake drum is mounted on the wheel hub. There is aclearance between the inner surface of the drum and the shoe lining. To apply brakes, the driver pushes pedal, the expander expands the shoes and presses them to the drum. Friction between the brake drum and the friction linings brakes the wheels and the vehicle stops. To release brakes, the driver release the pedal, the pull back spring retracts the shoes thus permitting free rotation of the wheels.Disk brakes, it has a metal disk instead of a drum. A flat shoe, or disk-brake pad, is located on each side of the disk. The shoes squeeze the rotatin g disk to stop the car. Fluid from the master cylinder forces the pistons to move in, toward the disk. This action pushes the friction pads tightly against the disk. The friction between the shoes and disk slows and stops it. This provides the braking action. Pistons are made of either plastic or metal. There are three general types of disk brakes. They are the floating-caliper type, the fixed-caliper type, and the sliding-caliper type. Floating-caliper and sliding-caliper disk brakes use a single piston. Fixed-caliper disk brakes have either two or four pistons.The brake system assemblies are actuated by mechanical, hydraulic or pneumatic devices. The mechanical leverage is used in the parking brakes fitted in all automobile. When the brake pedal is depressed, the rod pushes the piston of brake master cylinder which presses the fluid. The fluid flows through the pipelines to the power brake unit and then to the wheel cylinder. The fluid pressure expands the cylinder pistons thus pressing the shoes to the drum or disk. If the pedal is released, the piston returns to the initialposition, the pull backsprings retract the shoes, the fluid is forced back to the master cylinder and braking ceases.The primary purpose of the parking brake is to hold the vehicle stationary while it is unattended. The parking brake is mechanically operated by the driver when a separate parking braking hand lever is set. The hand brake is normally used when the car has already stopped. A lever is pulled and the rear brakes are approached and locked in the “on” position. The car may now be left without fear of its rolling away. When the driver wants to move the car again, he must press a button before the lever can be released. The hand brake must also be able to stop the car in the event of the foot brake failing. For this reason, it is separate from the foot brake uses cable or rods instead of the hydraulic system.Anti-lock Brake SystemAnti-lock brake systems make braking safer and more convenient, Anti-lock brake systems modulate brake system hydraulic pressure to prevent the brakes from locking and the tires from skidding on slippery pavement or during a panic stop.Anti-lock brake systems have been used on aircraft for years, and some domestic car were offered with an early form of anti-lock braking in late 1990’s. Recently, several automakers have introduced more sophisticated anti-lock system. Investigations in Europe, where anti-lock brakin g systems have been available for a decade, have led one manufacture to state that the number of traffic accidents could be reduced by seven and a half percent if all cars hadanti-lock brakes. So some sources predict that all cars will offer anti-lock brakes to improve the safety of the car.Anti-lock systems modulate brake application force several times per second to hold the tires at a controlled amount of slip; all systems accomplish this in basically the same way. One or more speed sensors generate alternating current signal whose frequency increases with the wheel rotational speed. An electronic control unit continuously monitors these signals and if the frequency of a signal drops too rapidly indicating that a wheel is about to lock, the control unit instructs a modulating device to reduce hydraulic pressure to the brake at the affected wheel. When sensor signals indicate the wheel is again rotating normally, the control unit allows increased hydraulic pressure to the brake. This release-apply cycle occurs several time per second to “pump” the brakes like a driver might but at a much faster rate.In addition to their basic operation, anti-lock systems have two other things in common. First, they do not operate until the brakes are applied with enough force to lock or nearly lock a wheel. At all other times, the system stands ready to function but does not interfere with normal braking. Second, if the anti-lock system fail in any way, the brakes continue to operate without anti-lock capability. A warning light on the instrument panel alerts the driver when a problem exists in the anti-lock system.The current Bosch component Anti-lock Braking System (ABSⅡ), is a second generation design wildly used by European automakers such as BWM,Mercedes-Benz and Porsche. ABSⅡsystem consists of : four wheel speed sensor, electronic control unit and modulator assembly.A speed sensor is fitted at each wheel sends signals about wheel rotation to control unit. Each speed sensor consists of a sensor unit and a gear wheel. The front sensor mounts to the steering knuckle and its gear wheel is pressed onto the stub axle that rotates with the wheel. The rear sensor mounts the rear suspension member and its gear wheel is pressed onto the axle. The sensor itself is a winding with a magnetic core. The core creates a magnetic field around the winding, and as the teeth of the gear wheel move through this field, an alternating current is induced in the winding. The control unit monitors the rate o change in this frequency to determine impending brake lockup.The cont rol unit’s function can be divided into three parts: signal processing, logic and safety circuitry. The signal processing section is the converter that receives the alternating current signals form the speed sensors and converts them into digital form for the logic section. The logic section then analyzes the digitized signals to calculate any brake pressure changes needed. If impending lockup is sensed, the logic section sends commands to the modulator assembly. Modulator assemblyThe hydraulic modulator assembly regulates pressure to the wheel brakes when it receives commands from the control utuit. The modulator assembly can maintain or reduce pressure over the level it receives from the master cylinder, it also can never apply the brakes by itself. The modulator assembly consists ofthree high-speed electric solenoid valves, two fluid reservoirs and a turn delivery pump equipped with inlet and outlet check valves. The modulator electrical connector and controlling relays are concealed under a plastic cover of the assembly.Each front wheel is served by electric solenoid valve modulated independently by the control unit. The rear brakes are served by a single solenoid valve and modulated together using the select-low principle. During anti-braking system operation, the control unit cycles the solenoid valves to either hold or release pressure the brake lines. When pressure is released from the brake lines during anti-braking operation, it is routed to a fluid reservoir. There is one reservoir for the front brake circuit. The reservoirs are low-pressure accumulators that store fluid under slight spring pressure until the return delivery pump can return the fluid through the brake lines to the master cylinder.汽车制动系统制动系统是汽车中最重要的系统。

(完整版)汽车制动系统英文文献及翻译)

Automobile Brake SystemThe braking system is the most important system in cars. If the brakes fail, the result can be disastrous. Brakes are actually energy conversion devices, which convert the kinetic energy (momentum) of the vehicle into thermal energy (heat).When stepping on the brakes, the driver commands a stopping force ten times as powerful as the force that puts the car in motion. The braking system can exert thousands of pounds of pressure on each of the four brakes.Two complete independent braking systems are used on the car. They are the service brake and the parking brake.The service brake acts to slow, stop, or hold the vehicle during normal driving. They are foot-operated by the driver depressing and releasing the brake pedal. The primary purpose of the brake is to hold the vehicle stationary while it is unattended. The parking brake is mechanically operated by when a separate parking brake foot pedal or hand lever is set.The brake system is composed of the following basic components: t he “master cylinder” which is located under the hood, and is directly connected to the brake pedal, converts driver foot’s mechanical pressure into hydraulic pressure. Steel “brake lines” and flexible “brake hoses” connect the master cylinder to the “slave cylinders” located at each wheel. Brake fluid, specially designed to work in extreme conditions, fills the system. “Shoes” and “pads” are pushed by the slave cylinders to contact the “drums” and “rotors” thus causing drag, which (hopefully) slows the car.The typical brake system consists of disk brakes in front and either disk or drum brakes in the rear connected by a system of tubes and hoses that link the brake at each wheel to the master cylinder (Figure).Basically, all car brakes are friction brakes. When the driver applies the brake, the control device forces brake shoes, or pads, against the rotating brake drum or disks at wheel. Friction between the shoes or pads and the drums or disks then slows or stops the wheel so that the car is braked.In most modern brake systems (see Figure 15.1), there is a fluid-filled cylinder, called master cylinder, which contains two separate sections, there is a piston in each section and both pistons are connected to a brake pedal in the driver’s compartment. When th e brake is pushed down, brake fluid is sent from the master cylinder to the wheels.At the wheels, the fluid pushes shoes, or pads, against revolving drums or disks. The friction between the stationary shoes, or pads, and the revolving drums or disks slows and stops them. This slows or stops the revolving wheels, which, in turn, slow or stop the car.The brake fluid reservoir is on top of the master cylinder. Most cars today have a transparent r reservoir so that you can see the level without opening the cover. The brake fluid level will drop slightly as the brake pads wear. This is a normal condition and no cause for concern. If the level drops noticeably over ashort period of time or goes down to about two thirds full, have your brakes checked as soon as possible. Keep the reservoir covered except for the amount of time you need to fill it and never leave a cam of brake fluid uncovered. Brake fluid must maintain a very high boiling point. Exposure to air will cause the fluid to absorb moisture which will lower that boiling point.The brake fluid travels from the master cylinder to the wheels through a series of steel tubes and reinforced rubber hoses. Rubber hoses are only used in places that require flexibility, such asat the front wheels, which move up and down as well as steer. The rest of the system uses non-corrosive seamless steel tubing with special fittings at all attachment points. If a steel line requires a repair, the best procedure is to replace the compete line. If this is not practical, a line can be repaired using special splice fittings that are made for brake system repair. You must never use copper tubing to repair a brake system. They are dangerous and illegal.Drum brakes, it consists of the brake drum, an expander, pull back springs, a stationary back plate, two shoes with friction linings, and anchor pins. The stationary back plate is secured to the flange of the axle housing or to the steering knuckle. The brake drum is mounted on the wheel hub. There is a clearance between the inner surface of the drum and the shoe lining. To apply brakes, the driver pushes pedal, the expander expands the shoes and presses them to the drum. Friction between the brake drum and the friction linings brakes the wheels and the vehicle stops. To release brakes, the driver release the pedal, the pull back spring retracts the shoes thus permitting free rotation of the wheels.Disk brakes, it has a metal disk instead of a drum. A flat shoe, or disk-brake pad, is located on each side of the disk. The shoes squeeze the rotatin g disk to stop the car. Fluid from the master cylinder forces the pistons to move in, toward the disk. This action pushes the friction pads tightly against the disk. The friction between the shoes and disk slows and stops it. This provides the braking action. Pistons are made of either plastic or metal. There are three general types of disk brakes. They are the floating-caliper type, the fixed-caliper type, and the sliding-caliper type. Floating-caliper and sliding-caliper disk brakes use a single piston. Fixed-caliper disk brakes have either two or four pistons.The brake system assemblies are actuated by mechanical, hydraulic or pneumatic devices. The mechanical leverage is used in the parking brakes fitted in all automobile. When the brake pedal is depressed, the rod pushes the piston of brake master cylinder which presses the fluid. The fluid flows through the pipelines to the power brake unit and then to the wheel cylinder. The fluid pressure expands the cylinder pistons thus pressing the shoes to the drum or disk. If the pedal is released, the piston returns to the initialposition, the pull back springs retract the shoes, the fluid is forced back to the master cylinder and braking ceases.The primary purpose of the parking brake is to hold the vehicle stationary while it is unattended. The parking brake is mechanically operated by the driver when a separate parking braking hand lever is set. The hand brake is normally used when the car has already stopped. A lever is pulled and t he rear brakes are approached and locked in the “on” position. The car may now be left without fear of its rolling away. When the driver wants to move the car again, he must press a button before the lever can be released. The hand brake must also be able to stop the car in the event of the foot brake failing. For this reason, it is separate from the foot brake uses cable or rods instead of the hydraulic system.Anti-lock Brake SystemAnti-lock brake systems make braking safer and more convenient, Anti-lock brake systems modulate brake system hydraulic pressure to prevent the brakes from locking and the tires from skidding on slippery pavement or during a panic stop.Anti-lock brake systems have been used on aircraft for years, and some domestic car were offered with an early form of anti-lock braking in late 1990’s. Recently, several automakers have introduced more sophisticated anti-lock system. Investigations in Europe, where anti-lock brakin g systems have been available for a decade, have led one manufacture to state that the number oftraffic accidents could be reduced by seven and a half percent if all cars had anti-lock brakes. So some sources predict that all cars will offer anti-lock brakes to improve the safety of the car.Anti-lock systems modulate brake application force several times per second to hold the tires at a controlled amount of slip; all systems accomplish this in basically the same way. One or more speed sensors generate alternating current signal whose frequency increases with the wheel rotational speed. An electronic control unit continuously monitors these signals and if the frequency of a signal drops too rapidly indicating that a wheel is about to lock, the control unit instructs a modulating device to reduce hydraulic pressure to the brake at the affected wheel. When sensor signals indicate the wheel is again rotating normally, the control unit allows increased hydraulic pressure to the brake. This release-apply cycle occurs several time per second to “pump” the brakes like a dr iver might but at a much faster rate.In addition to their basic operation, anti-lock systems have two other things in common. First, they do not operate until the brakes are applied with enough force to lock or nearly lock a wheel. At all other times, the system stands ready to function but does not interfere with normal braking. Second, if the anti-lock system fail in any way, the brakes continue to operate without anti-lock capability. A warning light on the instrument panel alerts the driver when a problem exists in the anti-lock system.The current Bosch component Anti-lock Braking System (ABSⅡ), is a second generation design wildly used by European automakers such as BWM, Mercedes-Benz and Porsche. ABSⅡsystem consists of : four wheel speed sensor, electronic control unit and modulator assembly.A speed sensor is fitted at each wheel sends signals about wheel rotation to control unit. Each speed sensor consists of a sensor unit and a gear wheel. The front sensor mounts to the steering knuckle and its gear wheel is pressed onto the stub axle that rotates with the wheel. The rear sensor mounts the rear suspension member and its gear wheel is pressed onto the axle. The sensor itself is a winding with a magnetic core. The core creates a magnetic field around the winding, and as the teeth of the gear wheel move through this field, an alternating current is induced in the winding. The control unit monitors the rate o change in this frequency to determine impending brake lockup.The control unit’s functi on can be divided into three parts: signal processing, logic and safety circuitry. The signal processing section is the converter that receives the alternating current signals form the speed sensors and converts them into digital form for the logic section. The logic section then analyzes the digitized signals to calculate any brake pressure changes needed. If impending lockup is sensed, the logic section sends commands to the modulator assembly.Modulator assemblyThe hydraulic modulator assembly regulates pressure to the wheel brakes when it receives commands from the control utuit. The modulator assembly can maintain or reduce pressure over the level it receives from the master cylinder, it also can never apply the brakes by itself. The modulator assembly consists of three high-speed electric solenoid valves, two fluid reservoirs and a turn delivery pump equipped with inlet and outlet check valves. The modulator electrical connector and controlling relays are concealed under a plastic cover of the assembly.Each front wheel is served by electric solenoid valve modulated independently by the control unit. The rear brakes are served by a single solenoid valve and modulated together using the select-low principle. During anti-braking system operation, the control unit cycles the solenoid valves to either hold or release pressure the brake lines. When pressure is released from the brakelines during anti-braking operation, it is routed to a fluid reservoir. There is one reservoir for the front brake circuit. The reservoirs are low-pressure accumulators that store fluid under slight spring pressure until the return delivery pump can return the fluid through the brake lines to the master cylinder.汽车制动系统制动系统是汽车中最重要的系统。

汽车制动系统中英文对照外文翻译文献

汽车制动系统中英文对照外文翻译文献(文档含英文原文和中文翻译)Brake systemsWe all know that pushing down on the brake pedal slows a car to a stop. But how does this happen? How does your car transmit the force from your leg to its wheels? How does it multiply the force so that it is enough to stop something as big as a car?Brake Image GalleryLayout of typical brake system. See more brake images.When you depress your brake pedal, your car transmits the force from your foot to its brakes through a fluid. Since the actual brakes require a much greater force than you could apply with your leg, your car must also multiply the force of your foot. It does this in two ways:∙Mechanical advantage (leverage)∙Hydraulic force multiplicationThe brakes transmit the force to the tires using friction, and the tires transmit that force to the road using friction also. Before we begin our discussion on the components of the brake system, we'll cover these three principles:∙Leverage∙Hydraulics∙FrictionLeverage and HydraulicsIn the figure below, a force F is being applied to the left end of the lever. The left end of the lever is twice as long (2X) as the right end (X). Therefore, on the right end of the lever a force of 2F is available, but it acts through half of the distance (Y) that the left end moves (2Y). Changing the relative lengths of the left and right ends of the lever changes the multipliers.The pedal is designed in such a way that it can multiply the force from yourleg several times before any force is even transmitted to the brake fluid.The basic idea behind any hydraulic system is very simple: Force applied at one point is transmitted to another point using an incompressible fluid, almost always an oil of some sort. Most brake systems also multiply the force in the process. Here you can see the simplest possible hydraulic system:Your browser does not support JavaScript or it is disabled.Simple hydraulic systemIn the figure above, two pistons (shown in red) are fit into two glass cylinders filled with oil (shown in light blue) and connected to one another with an oil-filled pipe. If youapply a downward force to one piston (the left one, in this drawing), then the force is transmitted to the second piston through the oil in the pipe. Since oil is incompressible, the efficiency is very good -- almost all of the applied force appears at the second piston. The great thing about hydraulic systems is that the pipe connecting the two cylinders can be any length and shape, allowing it to snake through all sorts of things separating the twopistons. The pipe can also fork, so that one master cylinder can drive more than one slave cylinder if desired, as shown in here:Your browser does not support JavaScript or it is disabled.Master cylinder with two slavesThe other neat thing about a hydraulic system is that it makes force multiplication (or division) fairly easy. If you have read How a Block and Tackle Works or How Gear Ratios Work, then you know that trading force for distance is very common in mechanical systems. In a hydraulic system, all you have to do is change the size of one piston and cylinder relative to the other, as shown here:Your browser does not support JavaScript or it is disabled.Hydraulic multiplicationTo determine the multiplication factor in the figure above, start by looking at the size of the pistons. Assume that the piston on the left is 2 inches (5.08 cm) in diameter (1-inch / 2.54 cm radius), while the piston on the right is 6 inches (15.24 cm) in diameter (3-inch / 7.62 cm radius). The area of the two pistons is Pi * r2. The area of the left piston is therefore 3.14, while the area of the piston on the right is 28.26. The piston on the right is nine times larger than the piston on the left. This means that any force applied to theleft-hand piston will come out nine times greater on the right-hand piston. So, if you apply a 100-pound downward force to the left piston, a 900-pound upward force will appear on the right. The only catch is that you will have to depress the left piston 9 inches (22.86 cm) to raise the right piston 1 inch (2.54 cm).A Simple Brake SystemBefore we get into all the parts of an actual car brake system, let's look at a simplified system:Your browser does not support JavaScript or it is disabled.A simple brake systemYou can see that the distance from the pedal to the pivot is four times the distance from the cylinder to the pivot, so the force at the pedal will be increased by a factor of four before it is transmitted to the cylinder.You can also see that the diameter of the brake cylinder is three times the diameter of the pedal cylinder. This further multiplies the force by nine. All together, this system increases the force of your foot by a factor of 36. If you put 10 pounds of force on the pedal, 360 pounds (162 kg) will be generated at the wheel squeezing the brake pads.There are a couple of problems with this simple system. What if we have a leak? If it is a slow leak, eventually there will not be enough fluid left to fill the brake cylinder, and the brakes will not function. If it is a major leak, then the first time you apply the brakes all of the fluid will squirt out the leak and you will have complete brake failure.Drum brakes work on the same principle as disc brakes: Shoes press against a spinning surface. In this system, that surface is called a drum.Figure 1. Location of drum brakes. See more drum brakepictures.Many cars have drum brakes on the rear wheels and disc brakes on the front. Drum brakes have more parts than disc brakes and are harder to service, but they are less expensive to manufacture, and they easily incorporate an emergency brake mechanism.In this edition of HowStuffWorks, we will learn exactly how a drum brake system works, examine the emergency brake setup and find out what kind of servicing drum brakes need.Figure 2. Drum brake with drum in placeFigure 3. Drum brake without drum in placeLet's start with the basics.The Drum BrakeThe drum brake may look complicated, and it can be pretty intimidating when you open one up. Let's break it down and explain what each piece does.Figure 4. Parts of a drum brakeLike the disc brake, the drum brake has two brake shoes and a piston. But the drum brake also has an adjuster mechanism, an emergency brake mechanism and lots of springs.First, the basics: Figure 5 shows only the parts that provide stopping power.Your browser does not support JavaScript or it is disabled.Figure 5. Drum brake in operationWhen you hit the brake pedal, the piston pushes the brake shoes against the drum. That's pretty straightforward, but why do we need all of those springs?This is where it gets a little more complicated. Many drum brakes are self-actuating. Figure 5 shows that as the brake shoes contact the drum, there is a kind of wedging action, which has the effect of pressing the shoes into the drum with more force.The extra braking force provided by the wedging action allows drum brakes to use a smaller piston than disc brakes. But, because of the wedging action, the shoes must be pulled away from the drum when the brakes are released. This is the reason for some of the springs. Other springs help hold the brake shoes in place and return the adjuster arm after it actuates.Brake AdjusterFor the drum brakes to function correctly, the brake shoes must remain close to the drum without touching it. If they get too far away from the drum (as the shoes wear down, for instance), the piston will require more fluid to travel that distance, and your brake pedal will sink closer to the floor when you apply the brakes. This is why most drum brakes have an automatic adjuster.Figure 6. Adjuster mechanismNow let's add in the parts of the adjuster mechanism. The adjuster uses theself-actuation principle we discussed above.Your browser does not support JavaScript or it is disabled.Figure 7. Drum brake adjuster in operationIn Figure 7, you can see that as the pad wears down, more space will form between the shoe and the drum. Each time the car stops while in reverse, the shoe is pulled tight against the drum. When the gap gets big enough, the adjusting lever rocks enough to advance the adjuster gear by one tooth. The adjuster has threads on it, like a bolt, so that it unscrews a little bit when it turns, lengthening to fill in the gap. When the brake shoes wear a little more, the adjuster can advance again, so it always keeps the shoes close to the drum.Some cars have an adjuster that is actuated when the emergency brake is applied. This type of adjuster can come out of adjustment if the emergency brake is not used forlong periods of time. So if you have this type of adjuster, you should apply your emergency brake at least once a week.ServicingThe most common service required for drum brakes is changing the brake shoes. Some drum brakes provide an inspection hole on the back side, where you can see how much material is left on the shoe. Brake shoes should be replaced when the friction material has worn down to within 1/32 inch (0.8 mm) of the rivets. If the friction material is bonded to the backing plate (no rivets), then the shoes should be replaced when they have only 1/16 inch (1.6 mm) of material left.Photo courtesy of a local AutoZone storeFigure 9. Brake shoeJust as in disc brakes, deep scores sometimes get worn into brake drums. If aworn-out brake shoe is used for too long, the rivets that hold the friction material to the backing can wear grooves into the drum. A badly scored drum can sometimes be repaired by refinishing. Where disc brakes have a minimum allowable thickness, drum brakes have a maximum allowable diameter. Since the contact surface is the inside of the drum, as you remove material from the drum brake the diameter gets bigger.Figure 10. Brake drum制动系统众所周知，踩下制动踏板可以使汽车减速至停止。

汽车制动安全技术英语词汇_交通运输英语词汇

abs─防抱死制动系统abs英文全称是“anti-lock brake system”。

没有abs时，汽车紧急制动时，四个车轮会被完全抱死，这时只要有轻微侧向力作用(比如倾斜的路面或者地上的一块小石头)，汽车就会发生侧滑，甩尾，甚至完全调头。

特别是在弯道行驶时，由于前轮抱死，汽车将因车轮缺乏附着而丧失转向能力，沿着惯性方向向前直至停止。

abs的功能就在于通过控制刹车油压的收放，达到对车轮抱死的控制。

当车轮制动时，安装在车轮上的传感器立即能感知车轮是否抱死，并将信号传给电脑，电脑会马上降低被抱死车轮的制动力，车轮又继续转动，转动到一定程度，电脑又施加制动，这样不断重复，直至汽车完全停下来。

通过“抱死-松开-抱死-松开”的循环工作，车辆始终处于临界抱死的间隙滚动状态。

安装abs后，汽车能显著改善制动性能，有效保证驾乘者的安全。

ebd/ebv─制动力分配装置ebd为英文缩写，其全称是“electric brake force distribution”。

其德文缩写为ebv，全称是“electronic?鄄sche bremsenkraft verteiler”。

通常情况下，由于四只轮胎附着地面的条件不同，因此，汽车制动时，很容易因轮胎与地面的摩擦力不同，产生打滑、倾斜和侧翻等现象。

ebd的功能就是在汽车制动的瞬间，分别计算出4个轮胎摩擦力数值，然后通过调整制动装置，达到制动力与摩擦力(牵引力)的匹配，以保证车辆的平稳和安全。

ebd主要是对abs起辅助功能，提高abs功效。

重踩刹车时，ebd 会在abs作用之前，依据车辆的重量分布和路面条件，有效分配制动力，以使4个车轮得到更接近理想化刹车力的分布。

因此，abs+ebd 就是在abs的基础上，平衡每一个轮的有效地面抓地力,改善刹车力的平衡，防止出现甩尾和侧移，并缩短汽车制动距离，使得汽车的安全性能更胜一筹。

esp─电子稳定程序esp英文全称是“electronic stability program”。

汽车制动系统英文文献及翻译)

Automobile Brake SystemThe braking system is the most important system in cars. If the brakes fail, the result can be disastrous. Brakes are actually energy conversion devices, which convert the kinetic energy (momentum) of the vehicle into thermal energy (heat).When stepping on the brakes, the driver commands a stopping force ten times as powerful as the force that puts the car in motion. The braking system can exert thousands of pounds of pressure on each of the four brakes.Two complete independent braking systems are used on the car. They are the service brake and the parking brake.The service brake acts to slow, stop, or hold the vehicle during normal driving. They are foot-operated by the driver depressing and releasing the brake pedal. The primary purpose of the brake is to hold the vehicle stationary while it is unattended. The parking brake is mechanically operated by when a separate parking brake foot pedal or hand lever is set.The brake system is composed of the following basic components: t he “master cylinder” which is located under the hood, and is directly connected to the brake pedal, converts driver foot’s mechanical pressure into hydraulic pressure. Steel “brake lines” and flexible “brake hoses” connect the master cylinder to the “slave cylinders” located at each wheel. Brake fluid, specially designed to work in extreme conditions, fills the system. “Shoes” and “pads” are pushed by the slave cylinders to contact the “drums” and “rotors” thus causing drag, which (hopefully) slows the car.The typical brake system consists of disk brakes in front andeither disk or drum brakes in the rear connected by a system of tubesand hoses that link the brake at each wheel to the master cylinder (Figure).Basically, all car brakes are friction brakes. When the driver applies the brake, the control device forces brake shoes, or pads, against the rotating brake drum or disks at wheel. Friction between the shoes or pads and the drums or disks then slows or stops the wheel sothat the car is braked.In most modern brake systems (see Figure 15.1), there is a fluid-filled cylinder, called master cylinder, which contains two separate sections, there is a piston in each section and both pistons are connected to a brake pedal in the driver’s compartme nt. When th e brake is pushed down, brake fluid is sent from the master cylinder to the wheels.At the wheels, the fluid pushes shoes, or pads, against revolving drums or disks. The friction between the stationary shoes, or pads, and the revolving drums or disks slows and stops them. This slows or stops the revolving wheels, which, in turn, slow or stop the car.The brake fluid reservoir is on top of the master cylinder. Most cars today have a transparent r reservoir so that you can see the level without opening the cover. The brake fluid level will drop slightly as the brake pads wear. This is a normal condition and no cause for concern. If the level drops noticeably over ashort period of time or goes down to about two thirds full, have your brakes checked as soon as possible. Keep the reservoir covered except for the amount of time you need tofill it and never leave a cam of brake fluid uncovered. Brake fluid must maintain a very high boiling point. Exposure to air will cause the fluid to absorb moisture which will lower that boiling point.The brake fluid travels from the master cylinder to the wheels through a series of steel tubes and reinforced rubber hoses. Rubber hoses are only used in places that require flexibility, such asat the front wheels, which move up and down as well as steer. The rest of the system uses non-corrosive seamless steel tubing with special fittings at all attachment points. If a steel line requires a repair, the best procedure is to replace the compete line. If this is not practical, a line can be repaired using special splice fittings that are made for brake system repair. You must never use copper tubing to repair a brake system. They are dangerous and illegal.Drum brakes, it consists of the brake drum, an expander, pull back springs, a stationary back plate, two shoes with friction linings, and anchor pins. The stationary back plate is secured to the flange of the axle housing or to the steering knuckle. The brake drum is mounted on the wheel hub. There is a clearance between the inner surface of the drum and the shoe lining. To apply brakes, the driver pushes pedal, the expander expands the shoes and presses them to the drum. Friction between the brake drum and the friction linings brakes the wheels and the vehicle stops. To release brakes, the driver release the pedal, the pull back spring retracts the shoes thus permitting free rotation of the wheels.Disk brakes, it has a metal disk instead of a drum. A flat shoe, or disk-brake pad, is located on each side of the disk. The shoes squeezethe rotatin g disk to stop the car. Fluid from the master cylinderforces the pistons to move in, toward the disk. This action pushes the friction pads tightly against the disk. The friction between the shoes and disk slows and stops it. This provides the braking action. Pistons are made of either plastic or metal. There are three general types of disk brakes. They are the floating-caliper type, the fixed-caliper type, and the sliding-caliper type. Floating-caliper and sliding-caliper disk brakes use a single piston. Fixed-caliper disk brakes have either two or four pistons.The brake system assemblies are actuated by mechanical, hydraulicor pneumatic devices. The mechanical leverage is used in the parking brakes fitted in all automobile. When the brake pedal is depressed, the rod pushes the piston of brake master cylinder which presses the fluid. The fluid flows through the pipelines to the power brake unit and thento the wheel cylinder. The fluid pressure expands the cylinder pistons thus pressing the shoes to the drum or disk. If the pedal is released, the piston returns to the initialposition, the pull back springs retract the shoes, the fluid is forced back to the master cylinder and braking ceases.The primary purpose of the parking brake is to hold the vehicle stationary while it is unattended. The parking brake is mechanically operated by the driver when a separate parking braking hand lever is set. The hand brake is normally used when the car has already stopped. Alever is pulled and t he rear brakes are approached and locked in the “on” position. The car may now be left without fear of its rolling away. When the driver wants to move the car again, he must press abutton before the lever can be released. The hand brake must also beable to stop the car in the event of the foot brake failing. For this reason, it is separate from the foot brake uses cable or rods instead of the hydraulic system.Anti-lock Brake SystemAnti-lock brake systems make braking safer and more convenient,Anti-lock brake systems modulate brake system hydraulic pressure to prevent the brakes from locking and the tires from skidding on slippery pavement or during a panic stop.Anti-lock brake systems have been used on aircraft for years, and some domestic car were offered with an early form of anti-lock braking in late 1990’s. Recently, several automakers have introduced more sophisticated anti-lock system. Investigations in Europe, where anti-lock brakin g systems have been available for a decade, have led one manufacture to state that the number oftraffic accidents could be reduced by seven and a half percent if all cars had anti-lock brakes. So some sources predict that all carswill offer anti-lock brakes to improve the safety of the car.Anti-lock systems modulate brake application force several times per second to hold the tires at a controlled amount of slip; all systems accomplish this in basically the same way. One or more speed sensors generate alternating current signal whose frequency increases with the wheel rotational speed. An electronic control unit continuously monitors these signals and if the frequency of a signal drops too rapidly indicating that a wheel is about to lock, the control unit instructs a modulating device to reduce hydraulic pressure to the brake at theaffected wheel. When sensor signals indicate the wheel is again rotating normally, the control unit allows increased hydraulic pressure to the brake. This release-apply cycle occurs several time per second to “pump” the brakes like a dr iver might but at a much faster rate.In addition to their basic operation, anti-lock systems have two other things in common. First, they do not operate until the brakes are applied with enough force to lock or nearly lock a wheel. At all other times, the system stands ready to function but does not interfere with normal braking. Second, if the anti-lock system fail in any way, the brakes continue to operate without anti-lock capability. A warning light on the instrument panel alerts the driver when a problem exists in the anti-lock system.The current Bosch component Anti-lock Braking System (ABSⅡ), is a second generation design wildly used by European automakers such as BWM, Mercedes-Benz and Porsche. ABSⅡsystem consists of : fou r wheel speed sensor, electronic control unit and modulator assembly.A speed sensor is fitted at each wheel sends signals about wheel rotation to control unit. Each speed sensor consists of a sensor unitand a gear wheel. The front sensor mounts to the steering knuckle andits gear wheel is pressed onto the stub axle that rotates with the wheel. The rear sensor mounts the rear suspension member and its gear wheel is pressed onto the axle. The sensor itself is a winding with a magnetic core. The core creates a magnetic field around the winding, and as the teeth of the gear wheel move through this field, an alternating current is induced in the winding. The control unit monitors the rate o changein this frequency to determine impending brake lockup.The control unit’s functi on can be divided into three parts:signal processing, logic and safety circuitry. The signal processing section is the converter that receives the alternating current signals form the speed sensors and converts them into digital form for the logic section. The logic section then analyzes the digitized signals to calculate any brake pressure changes needed. If impending lockup is sensed, the logic section sends commands to the modulator assembly.Modulator assemblyThe hydraulic modulator assembly regulates pressure to the wheel brakes when it receives commands from the control utuit. The modulator assembly can maintain or reduce pressure over the level it receives from the master cylinder, it also can never apply the brakes by itself. The modulator assembly consists of three high-speed electric solenoid valves, two fluid reservoirs and a turn delivery pump equipped with inlet and outlet check valves. The modulator electrical connector and controlling relays are concealed under a plastic cover of the assembly.Each front wheel is served by electric solenoid valve modulated independently by the control unit. The rear brakes are served by asingle solenoid valve and modulated together using the select-low principle. During anti-braking system operation, the control unit cycles the solenoid valves to either hold or release pressure the brake lines. When pressure is released from the brakelines during anti-braking operation, it is routed to a fluid reservoir. There is one reservoir for the front brake circuit. The reservoirs are low-pressure accumulators that store fluid under slightspring pressure until the return delivery pump can return the fluid through the brake lines to the master cylinder.汽车制动系统制动系统是汽车中最重要的系统。

汽车英语_Braking System

The Professional Words of Braking System制动系braking system行车制动系统service braking system应急制动系统secondary (emergency )braking system驻车制动系统parking braking system辅助制动系统auxiliary braking system自动制动系统automatic braking system人力制动系统muscular energy braking system助力制动系统energy assisted braking system动力制动系统non-muscular energy braking system惯性制动系统inertial braking system重力制动系统gravity braking system单回路制动系统single-circuit braking system双回路制动系统dual -circuit braking system单管路制动系统single-line braking system双管路制动系统dual braking system多管路制动系统multi-line braking system伺服制动系统servo braking system液压制动系统hydraulic braking system电磁制动系统electromagnetic braking system机械制动系统mechanical braking system渐进制动gradual braking制动能源braking energy source制动力矩braking torque总制动力total braking force总制动距离total braking distance有效制动距离active braking distance制动力分配率braking force distribution rate制动效能因素（制动强度）braking efficiency factor 制动力braking force瞬时制动功率instantaneous braking power停车距离（制动距离）stopping distance制动反应时间reaction time有效制动时间active braking time驾驶员反应时间reaction time of driver总制动时间total braking time单轮控制individual wheel control多轮控制multi-wheel control控制频率control frequency制动器效能因素application force制动器输出力矩brake output torque制动器额定力矩brake rating torque制动蹄效能因素brake shoe efficiency factor制动蹄作用压力application pressure of brake shoe assembly 制动蹄释放压力release pressure of brake shoe（鼓或盘）的摩擦面积swept area踏板行程pedal travel踏板自由行程free pedal travel踏板最大行程maximum pedal travel有效踏板长度effective pedal length制动初速度initial speed of braking制动减速度braking deceleration瞬时制动减速度instantaneous braking deceleration平均制动减速度mean braking deceleration最大制动减速度maximum braking deceleration冷却液cooling liquid供能装置energy supplying device真空泵vacuum pump空压机air compressor调压阀pressure regulating valve单向阀single check valve(one-way valve; retaining valve)止回阀、单向阀check valve控制装置control device行车制动踏板装置service braking pedal device制动踏板braking pedal衬套bushing回位弹簧return spring操纵杆control lever制动杆brake lever推杆plunger气阀air valve平衡弹簧equalizing spring快泄阀quick release valve制动主缸brake master cylinder弹簧座spring seat活塞挡圈piston stopper主缸储液室master cylinder reservoir 进油阀inlet valve轮缸wheel cylinder伺服机构servo mechanism助力器booster真空助力器vacuum booster伺服阀servo valve控制膜片control diaphragm液压阀hydraulic valve管路pipe-line制动管路braking line应急制动管路secondary line制动软管总成brake hose assemblies制动软管braking hose液压软管hydraulic hose密封圈sealing ring压力环pressure ring摩擦式制动器friction brake鼓式制动器drum brake盘式制动器disc brake多片盘式制动器multiple disc brake挂车制动器trailer brake超速制动器overrun brake液压制动器hydraulic brake双领蹄式制动器two leading shoe brake双从蹄式制动器two trailing shoe brake双向双领蹄式制动器dual two leading shoe brake 双向双从蹄式制动器dual two trailing shoe brake 领从蹄式制动器leading trailing shoe brake带式制动器band brake钳盘式制动器caliper disc brake定钳盘式制动器disc brake with fixed caliper浮钳盘式制动器disc brake with floating caliper浮盘式制动器floating disc brake凸轮制动器cam brake楔式制动器wedge brake驻车制动器parking brake手制动器hand brake制动鼓brake drum制动鼓衬里brake drum liner制动蹄brake shoe制动蹄总成brake shoe assembly领蹄（紧蹄）primary shoe(leading shoe) 从蹄（松蹄）secondary shoe(trailing shoe) 制动凸轮轴brake camshaft制动蹄回位弹簧brake shoe return spring 支承销anchor pin支承块anchor plate制动带brake band制动盘brake disc制动钳brake caliper制动衬片brake lining减速器、缓冲器retarder传感器sensor/transducer控制器controller调节器modulator限压阀pressure limiting valve比例阀proportioning valve惯性防抱死装置inertia anti-lock device电子防抱死装置electronic anti-lock device 报警装置warning device真空报警开关vacuum warning switch低压报警开关low pressure warning switch 附加装置additional device调压阀pressure regulating valve安全阀relief valve(safety valve)液压继动阀hydraulic relay valve手制动阀hand brake valve制动灯开关braking light switch鉴定试验qualification test试验设备（台）test rig制动拖滞braking drag制动颤振brake chatter制动噪声brake noise制动跑偏braking deviation制动失效braking failure制动滑移braking skid后轮防抱死制动系统rear wheel antilock system两轮防抱死制动系统two-wheel antilock braking system整体（组合）式防抱死系统integrated/integral antilock system 附加（分置）式防抱死制动系统add on antilock system;nonintegral/independent antilock system 3通道式防抱死系统3-channel antilock system对角线分路式防抱死制动系统diagonal split antilock system前/后轮分路式防抱死制动系统front/real split antilock system 车轮制动器wheel brake。

f1汽车制动系统外文翻译

汽车制动系统英文文献及翻译

Automobile Brake System汽车制动系统The braking system is the most important system in cars. If the brakes fail, the result can be disastrous. Brakes are actually energy conversion devices, which convert the kinetic energy (momentum) of the vehicle into thermal energy (heat).When stepping on the brakes, the driver commands a stopping force ten times as powerful as the force that puts the car in motion. The braking system can exert thousands of pounds of pressure on each of the four brakes.Two complete independent braking systems are used on the car. They are the service brake and the parking brake.The service brake acts to slow, stop, or hold the vehicle during normal driving. They are foot-operated by the driver depressing and releasing the brake pedal. The primary purpose of the brake is to hold the vehicle stationary while it is unattended. The parking brake is mechanically operated by when a separate parking brake foot pedal or hand lever is set.The brake system is composed of the following basic compone nts: the “master cylinder” which is locatedunder the hood, and is directly connected to the brake pedal, converts driver foot’s mechanical pressure into hydraulic pressure. Steel “brake lines” and flexible “brake hoses” connect the master cylinder to the “slave cylinders” located at each wheel. Brake fluid, specially designed to work in extreme conditions, fills the system. “Shoes” and “pads” are pushed by the slave cylinders to contact the “drums” and “rotors” thus causing drag, which (hopefully) slows the car.The typical brake system consists of disk brakes in front and either disk or drum brakes in the rear connected by a system of tubes and hoses that link the brake at each wheel to the master cylinder (Figure).Basically, all car brakes are friction brakes. When the driver applies the brake, the control device forces brake shoes, or pads, against the rotating brake drum or disks at wheel. Friction between the shoes or pads and the drums or disks then slows or stops the wheel so that the car is braked.In most modern brake systems (see Figure 15.1), there is a fluid-filled cylinder, called master cylinder, which contains two separate sections, there is a piston ineach section and both pistons are connected to a brake pedal in the driver’s compartment. W hen the brake is pushed down, brake fluid is sent from the master cylinder to the wheels.At the wheels, the fluid pushes shoes, or pads, against revolving drums or disks. The friction between the stationary shoes, or pads, and the revolving drums or disks slows and stops them. This slows or stops the revolving wheels, which, in turn, slow or stop the car.The brake fluid reservoir is on top of the master cylinder. Most cars today have a transparent r reservoir so that you can see the level without opening the cover. The brake fluid level will drop slightly as the brake pads wear. This is a normal condition and no cause for concern. If the level drops noticeably over ashort period of time or goes down to about two thirds full, have your brakes checked as soon as possible. Keep the reservoir covered except for the amount of time you need to fill it and never leave a cam of brake fluid uncovered. Brake fluid must maintain a very high boiling point. Exposure to air will cause the fluid to absorb moisture which will lower that boiling point.The brake fluid travels from the master cylinder to the wheels through a series of steel tubes and reinforced rubber hoses. Rubber hoses are only used in places that require flexibility, such as at the front wheels, which move up and down as well as steer. The rest of the system uses non-corrosive seamless steel tubing with special fittings at all attachment points. If a steel line requires a repair, the best procedure is to replace the compete line. If this is not practical, a line can be repaired using special splice fittings that are made for brake system repair. You must never use copper tubing to repair a brake system. They are dangerous and illegal.Drum brakes, it consists of the brake drum, an expander, pull back springs, a stationary back plate, two shoes with friction linings, and anchor pins. The stationary back plate is secured to the flange of the axle housing or to the steering knuckle. The brake drum is mounted on the wheel hub. There is a clearance between the inner surface of the drum and the shoe lining. To apply brakes, the driver pushes pedal, the expander expands the shoes and presses them to the drum. Friction between the brake drum and the friction liningsbrakes the wheels and the vehicle stops. To release brakes, the driver release the pedal, the pull back spring retracts the shoes thus permitting free rotation of the wheels.Disk brakes, it has a metal disk instead of a drum. A flat shoe, or disk-brake pad, is located on each side of the disk. The shoes squeeze the rotatin g disk to stop the car. Fluid from the master cylinder forces the pistons to move in, toward the disk. This action pushes the friction pads tightly against the disk. The friction between the shoes and disk slows and stops it. This provides the braking action. Pistons are made of either plastic or metal. There are three general types of disk brakes. They are the floating-caliper type, the fixed-caliper type, and the sliding-caliper type. Floating-caliper and sliding-caliper disk brakes use a single piston. Fixed-caliper disk brakes have either two or four pistons.The brake system assemblies are actuated by mechanical, hydraulic or pneumatic devices. The mechanical leverage is used in the parking brakes fitted in all automobile. When the brake pedal is depressed, the rod pushes the piston of brake master cylinder whichpresses the fluid. The fluid flows through the pipelines to the power brake unit and then to the wheel cylinder. The fluid pressure expands the cylinder pistons thus pressing the shoes to the drum or disk. If the pedal is released, the piston returns to the initialposition, the pull back springs retract the shoes, the fluid is forced back to the master cylinder and braking ceases.The primary purpose of the parking brake is to hold the vehicle stationary while it is unattended. The parking brake is mechanically operated by the driver when a separate parking braking hand lever is set. The hand brake is normally used when the car has already stopped.A lever is pulled and the rear brakes are approached and locked in the “on” position. The car may now be left without fear of its rolling away. When the driver wants to move the car again, he must press a button before the lever can be released. The hand brake must also be able to stop the car in the event of the foot brake failing. For this reason, it is separate from the foot brake uses cable or rods instead of the hydraulic system.Anti-lock Brake SystemAnti-lock brake systems make braking safer and moreconvenient, Anti-lock brake systems modulate brake system hydraulic pressure to prevent the brakes from locking and the tires from skidding on slippery pavement or during a panic stop.Anti-lock brake systems have been used on aircraft for years, and some domestic car were offered with an early form of anti-lock braking in late 1990’s. Recently, several automakers have introduced more sophisticated anti-lock system. Investigations in Europe, where anti-lock brakin g systems have been available for a decade, have led one manufacture to state that the number of traffic accidents could be reduced by seven and a half percent if all cars had anti-lock brakes. So some sources predict that all cars will offer anti-lock brakes to improve the safety of the car.Anti-lock systems modulate brake application force several times per second to hold the tires at a controlled amount of slip; all systems accomplish this in basically the same way. One or more speed sensors generate alternating current signal whose frequency increases with the wheel rotational speed. An electronic control unit continuously monitors these signals and if thefrequency of a signal drops too rapidly indicating that a wheel is about to lock, the control unit instructs a modulating device to reduce hydraulic pressure to the brake at the affected wheel. When sensor signals indicate the wheel is again rotating normally, the control unit allows increased hydraulic pressure to the brake. This release-apply cycle occurs several time per second to “pump” the brakes lik e a driver might but at a much faster rate.In addition to their basic operation, anti-lock systems have two other things in common. First, they do not operate until the brakes are applied with enough force to lock or nearly lock a wheel. At all other times, the system stands ready to function but does not interfere with normal braking. Second, if the anti-lock system fail in any way, the brakes continue to operate without anti-lock capability. A warning light on the instrument panel alerts the driver when a problem exists in the anti-lock system.The current Bosch component Anti-lock Braking System (ABSⅡ), is a second generation design wildly used by European automakers such as BWM,Mercedes-Benz and Porsche. ABSⅡsystem consists of : four wheel speed sensor, electronic control unit and modulator assembly.A speed sensor is fitted at each wheel sends signals about wheel rotation to control unit. Each speed sensor consists of a sensor unit and a gear wheel. The front sensor mounts to the steering knuckle and its gear wheel is pressed onto the stub axle that rotates with the wheel. The rear sensor mounts the rear suspension member and its gear wheel is pressed onto the axle. The sensor itself is a winding with a magnetic core. The core creates a magnetic field around the winding, and as the teeth of the gear wheel move through this field, an alternating current is induced in the winding. The control unit monitors the rate o change in this frequency to determine impending brake lockup.The control unit’s function can be divided into three parts: signal processing, logic and safety circuitry. The signal processing section is the converter that receives the alternating current signals form the speed sensors and converts them into digital form for the logic section. The logic section then analyzes the digitized signals tocalculate any brake pressure changes needed. If impending lockup is sensed, the logic section sends commands to the modulator assembly.Modulator assemblyThe hydraulic modulator assembly regulates pressure to the wheel brakes when it receives commands from the control utuit. The modulator assembly can maintain or reduce pressure over the level it receives from the master cylinder, it also can never apply the brakes by itself. The modulator assembly consists of three high-speed electric solenoid valves, two fluid reservoirs and a turn delivery pump equipped with inlet and outlet check valves. The modulator electrical connector and controlling relays are concealed under a plastic cover of the assembly.Each front wheel is served by electric solenoid valve modulated independently by the control unit. The rear brakes are served by a single solenoid valve and modulated together using the select-low principle. During anti-braking system operation, the control unit cycles the solenoid valves to either hold or release pressure the brake lines. When pressure is released from the brake lines during anti-braking operation, it is routedto a fluid reservoir. There is one reservoir for the front brake circuit. The reservoirs are low-pressure accumulators that store fluid under slight spring pressure until the return delivery pump can return the fluid through the brake lines to the master cylinder.汽车制动系统制动系统是汽车中最重要的系统。

汽车专业英语翻译1

汽车专业英语翻译1Body：车身Engine：发动机Brakes：制动器Power train：传动系Steering：转向系Electrical：电器及电子设备Suspension：悬架Layout of a passenger car：乘用车总布置Layout of a commercial vehicle：商用车总布置1.1 车身汽车车身是由车窗、车门、发动机罩和行李箱盖焊接在金属板外壳内而成。

金属板外壳将发动机、乘客和物资覆盖以提供爱护。

车身的设计要保证乘客安全舒服。

车身的款式使得汽车看起来漂亮迷人、色彩斑斓、时尚前卫。

私家轿车有一个封装起来的车身，4个大车门承诺乘客进出车厢。

那个设计也可放置行李或其他物资。

私家轿车也能够称为拥有固定车顶的传统车辆。

有许多类似车身设计的活顶式车除了拥有两个车门，其他的设计和敞篷车大致一样。

皮卡或载重汽车。

通常它们有比轿车大的底盘和悬架来支撑重物质量。

型运载货车基于轿车的设计并改装以便腾出最大限度的空间来装载物资。

商用运载物资车辆的车身是专用设计的。

如罐车运载液体，自卸车搬运泥土或大批谷物，平板车和货车通常用来运载一般物资。

公交车或长途汽车通常是4轮固定模式的车辆，但会用到大量的车轮和轮轴。

有时，铰接式公交车是为了增加容量。

公交车和货车能够做成单层或双层的。

长途汽车常用于长距离运载，且费用比较昂贵，因此市区里就会用到公交车，如市郊间上下班时用于交通运输。

1.2 发动机发动机作为动力装置。

最常见的内燃机通过燃烧发动机气缸里的液体燃料而获得能量。

内燃机有两种类型：汽油机（又称为点燃式发动机）和柴油机（又称为压燃式发动机）。

两种类型均称为热力发动机。

燃烧燃料产生的热量使汽缸里气体的气压增加并提供能量通过传动轴连接到传动系统。

发动机气缸的排列方式称为发动机配置。

直列式发动机的汽缸呈一列布置。

那个设计制造了一个简单的发动机缸体铸造。

在车辆应用中，汽缸数一样是2-6缸，汽缸中心线与水平面垂直。

中英文文献翻译-汽车制动系统概述

附录Automobile Brake SystemThe braking system is the most important system in cars. If the brakes fail，the result can be disastrous. Brakes are actually energy conversion devices，which convert the kinetic energy (momentum) of the vehicle into thermal energy (heat).When stepping on the brakes，the driver commands a stopping force ten times as powerful as the force that puts the car in motion. The braking system can exert thousands of pounds of pressure on each of the four brakes.Two complete independent braking systems are used on the car. They are the service brake and the parking brake.The service brake acts to slow，stop，or hold the vehicle during normal driving. They are foot-operated by the driver depressing and releasing the brake pedal. The primary1—Brake hose 2—Master cylinder 3—Power brake 4—Brake pedal 5—parkingbrake 6—Parking brake cable 7—Brake drum 8—Proportioning valve 9—Brake warning light switch 10—Metering valve 11—Disc brake 12—Brake linepurpose of the brake is to hold the vehicle stationary while it is unattended. The parking brake is mechanically operated by when a separate parking brake foot pedal or hand lever is set.The brake system is composed of the following basic components: the “master cylinder” which is located under the hood，and is directly connected to the brake pedal，converts driver foot’s mechanical pressure into hydraulic pressure. Steel “brake lines” and flexible “brake hoses” connect the master cylinder to the “slave cylinders” located at each wheel. Brake fluid，specially designed to work in extreme conditions，fills the system.“Shoes” and “pads” are pushed by the slave cylinders to contact the “drums” and “rotors” thus causing drag，which (hopefully) slows the car.The typical brake system consists of disk brakes in front and either disk or drum brakes in the rear connected by a system of tubes and hoses that link the brake at each wheel to the master cylinder (Figure).Basically，all car brakes are friction brakes. When the driver applies the brake，the control device forces brake shoes，or pads，against the rotating brake drum or disks at wheel. Friction between the shoes or pads and the drums or disks then slows or stops the wheel so that the car is braked.In most modern brake systems (see Figure 15.1)，there is a fluid-filled cylinder，called master cylinder，which contains two separate sections，there is a piston in each section and both pistons are connected to a brake pedal in the driver’s compartment. When the brake is pushed down，brake fluid is sent from the master cylinder to the wheels. At the wheels，the fluid pushes shoes，or pads，against revolving drums or disks. The friction between the stationary shoes，or pads，and the revolving drums or disks slows and stops them. This slows or stops the revolving wheels，which，in turn，slow or stop the car. The brake fluid reservoir is on top of the master cylinder. Most cars today have a transparent r reservoir so that you can see the level without opening the cover. The brake fluid level will drop slightly as the brake pads wear. This is a normal condition and no cause for concern. If the level drops noticeably over a short period of time or goes down to about two thirds full，have your brakes checked as soon as possible. Keep the reservoir covered except for the amount of time you need to fill it and never leave a cam of brake fluid uncovered. Brake fluid must maintain a very high boiling point. Exposure to air will cause the fluid to absorb moisture which will lower that boiling point.The brake fluid travels from the master cylinder to the wheels through a series of steel tubes and reinforced rubber hoses. Rubber hoses are only used in places that require flexibility，such as at the front wheels，which move up and down as well as steer. The rest of the system uses non-corrosive seamless steel tubing with special fittings at all attachment points. If a steel line requires a repair，the best procedure is to replace the compete line. If this is not practical，a line can be repaired using special splice fittings that are made for brake system repair. You must never use copper tubing to repair a brake system. They are dangerous and illegal.Drum brakes，it consists of the brake drum，an expander，pull back springs，a stationary back plate，two shoes with friction linings，and anchor pins. The stationary back plate is secured to the flange of the axle housing or to the steering knuckle. The brake drum is mounted on the wheel hub. There is a clearance between the inner surface of the drum and the shoe lining. To apply brakes，the driver pushes pedal，the expander expands the shoes and presses them to the drum. Friction between the brake drum and the friction linings brakes the wheels and the vehicle stops. To release brakes，the driver release the pedal，the pull back spring retracts the shoes thus permitting free rotation of the wheels.Disk brakes，it has a metal disk instead of a drum. A flat shoe，or disk-brake pad，is located on each side of the disk. The shoes squeeze the rotating disk to stop the car. Fluid from the master cylinder forces the pistons to move in，toward the disk. This action pushes the friction pads tightly against the disk. The friction between the shoes and disk slows and stops it. This provides the braking action. Pistons are made of either plastic or metal. There are three general types of disk brakes. They are the floating-caliper type，the fixed-caliper type，and the sliding-caliper type. Floating-caliper and sliding-caliper disk brakes use a single piston. Fixed-caliper disk brakes have either two or four pistons.The brake system assemblies are actuated by mechanical，hydraulic or pneumatic devices. The mechanical leverage is used in the parking brakes fitted in all automobile. When the brake pedal is depressed，the rod pushes the piston of brake master cylinder which presses the fluid. The fluid flows through the pipelines to the power brake unit and then to the wheel cylinder. The fluid pressure expands the cylinder pistons thus pressing the shoes to the drum or disk. If the pedal is released，the piston returns to the initial position，the pull back springs retract the shoes，the fluid is forced back to the master cylinder and braking ceases.The primary purpose of the parking brake is to hold the vehicle stationary while it is unattended. The parking brake is mechanically operated by the driver when a separate parking braking hand lever is set. The hand brake is normally used when the car has already stopped. A lever is pulled and the rear brakes are approached and locked in the “on” position. The car may now be left without fear of its rolling away. When the driver wants to move the car again，he must press a button before the lever can be released. The hand brake must also be able to stop the car in the event of the foot brake failing. For this reason，it is separate from the foot brake uses cable or rods instead of the hydraulic system.Anti-lock Brake SystemAnti-lock brake systems make braking safer and more convenient，Anti-lock brake systems modulate brake system hydraulic pressure to prevent the brakes from locking and the tires from skidding on slippery pavement or during a panic stop.Anti-lock brake systems have been used on aircraft for years，and some domestic car were offered with an early form of anti-lock braking in late 1990’s. Recently，several automakers have introduced more sophisticated anti-lock system. Investigations in Europe，where anti-lock braking systems have been available for a decade，have led one manufacture to state that the number of traffic accidents could be reduced by seven and a half percent if all cars had anti-lock brakes. So some sources predict that all cars will offer anti-lock brakes to improve the safety of the car.Anti-lock systems modulate brake application force several times per second to hold the tires at a controlled amount of slip; all systems accomplish this in basically the same way. One or more speed sensors generate alternating current signal whose frequency increases with the wheel rotational speed. An electronic control unit continuously monitors these signals and if the frequency of a signal drops too rapidly indicating that a wheel is about to lock，the control unit instructs a modulating device to reduce hydraulic pressure to the brake at the affected wheel. When sensor signals indicate the wheel is again rotating normally，the control unit allows increased hydraulic pressure to the brake. This release-apply cycle occurs several time per second to “pump” the brakes like a driver might but at a much faster rate.In addition to their basic operation，anti-lock systems have two other things in common. First，they do not operate until the brakes are applied with enough force to lock or nearly lock a wheel. At all other times，the system stands ready to function but does not interfere with normal braking. Second，if the anti-lock system fail in any way，the brakes continue to operate without anti-lock capability. A warning light on the instrument panel alerts the driver when a problem exists in the anti-lock system.The current Bosch component Anti-lock Braking System (ABSⅡ)，is a second generation design wildly used by European automakers such as BWM，Mercedes-Benz and Porsche. ABSⅡsystem consists of : four wheel speed sensor，electronic control unit and modulator assembly.A speed sensor is fitted at each wheel sends signals about wheel rotation to control unit.Each speed sensor consists of a sensor unit and a gear wheel. The front sensor mounts to the steering knuckle and its gear wheel is pressed onto the stub axle that rotates with the wheel. The rear sensor mounts the rear suspension member and its gear wheel is pressed onto the axle. The sensor itself is a winding with a magnetic core. The core creates a magnetic field around the winding，and as the teeth of the gear wheel move through this field，an alternating current is induced in the winding. The control unit monitors the rate o change in this frequency to determine impending brake lockup.The control unit’s function can be divided into three parts: signal processing，logic and safety circuitry. The signal processing section is the converter that receives the alternating current signals form the speed sensors and converts them into digital form for the logic section. The logic section then analyzes the digitized signals to calculate any brake pressure changes needed. If impending lockup is sensed，the logic section sends commands to the modulator assembly.Modulator assemblyThe hydraulic modulator assembly regulates pressure to the wheel brakes when it receives commands from the control utuit. The modulator assembly can maintain or reduce pressure over the level it receives from the master cylinder，it also can never apply the brakes by itself. The modulator assembly consists of three high-speed electric solenoid valves，two fluid reservoirs and a turn delivery pump equipped with inlet and outlet check valves. The modulator electrical connector and controlling relays are concealed under a plastic cover of the assembly.Each front wheel is served by electric solenoid valve modulated independently by the control unit. The rear brakes are served by a single solenoid valve and modulated together using the select-low principle. During anti-braking system operation，the control unit cycles the solenoid valves to either hold or release pressure the brake lines. When pressure is released from the brake lines during anti-braking operation，it is routed to a fluid reservoir. There is one reservoir for the front brake circuit. The reservoirs are low-pressure accumulators that store fluid under slight spring pressure until the return delivery pump can return the fluid through the brake lines to the master cylinder.汽车制动系统制动系统是汽车中最重要的系统。

1215毕业设计汽车制动外文翻译(外文)

Nonlinear Dyn (2014) 76:125–138DOI10.1007/s11071-013-1115-1翻译！Robustcontrolofwheelslipinanti-lockbrakesystem ofautomobilesTohidSardarmehni·HosseinRahmani·Mohammad BagherMenhajReceived:3November2012/Accepted:9October2013/Publishedonline:6November2013© Springer Science+Business Media Dordrecht2013Abstract In this paper, performances of two model- free control systems including Fuzzy Logic Control (FLC) and Neural Predictive Control (NPC) on track- ing performance of wheel-slip in Anti-lock Braking System (ABS) are compared. As an accurate andcon- trol oriented model, a half vehicle model is devel- opedtogenerateextensivesimulationdataofthebrak- ing system. Brake system identification is preformed through a Perceptron neural networks model of brake system which is trained with offline data by Gradi- ent Descent Back Propagation (GDBP) algorithm. In order to reduce the time cost of the calculations and improving the robustness of closed loop control sys- tem, an online Perceptron neural network adaptively generatestheoptimumcontrolactions.Byacompara- tive simulation analysis it is shown that the NPC sys- tem has a better tracking performance, shorter stop- ping time and distance than the FLC controllers. The robustness of the proposed control systems are eval- uated under ±25 % uncertainty. It is shown that the NPC system is more robust against both exogenous disturbances and modeling uncertainties than theFLC system.T. Sardarmehni(B) ·H.Rahmani FacultyofMechanicalEngineering,UniversityofTabriz, Tabriz,Irane-mail:t.sardarmehni88@ms.tabrizu.ac.irM.B.MenhajDepartment of Electrical Engineering,AmirkabirUniversity of Technology, Tehran,Iran Keywords ABS ·NPC ·FLCAbbreviationsFLC FuzzyLogicControlNPCNeuralPredictiveControlABS Anti-lock BrakingSystemGDBP Gradient Descent Back PropagationECU Electronic ControlUnitSMC SlidingModecontrolMPCModelPredictiveControlMLP Multi-LayerPerceptronMAE MeanAbsoluteErrorMATE Mean Absolute TrackingErrorVehicle brake systemparametersV Vehicle velocity[m/s]ωWheel angular velocity[rad/s]g Gravity acceleration[m/s2]R Radius of tire[m]J f Moment of inertia of front wheel [kgm2]J r Moment of inertia of rear wheel [kgm2]a Distance from center of gravity to frontaxle[m]b Distance from center of gravity to rearaxle[m]h f Height of front unsprung mass[m]h s Height of the sprung mass[m]h r Height of rear unsprung mass[m]m f Front unsprung mass[kg]m s Sprung mass of the vehicle[kg]m r Rear unsprung mass[kg]126T. Sardarmehni etal. Fig. 1 Friction coefficientversus wheel slip[2]m tot Total mass of the vehicle[kg]P i Hydraulic pressure[kPa]P p Constantpumppressure[kPa]P low Constantreservoirpressure[kPa]C d1 BuildvalvecoefficientC d2Dumpvalvecoefficient A wc Wheelcylinderarea[m 2]hMechanicalefficiencyB F Brakefactorr r Effective radius of braking disk[m]C f CoefficientofflowK br Brake displacement proportionalityconstant1 IntroductionReducingrequiredstoppingtimeanddistanceinbrak- inghasalwaysbeenoneofthemostimportantcontrol goalsindesigningthebrakingsystemsofautomobiles. Without any control on angular velocity of wheels,an ordinary braking system exerts dissident fixed brak- ing torque on wheels. This fixed torque causes abrupt decrease in wheel angular velocity with a greater rate than the vehicle speed which results in wheel lock- ups during braking. Through locking-up, friction co- efficient and road adhesion become smaller which re- ducestheactive-appliedbrakingtorqueontires.Asthe result, the stopping time increases and vehicle stops afteralongerdistance.Furthermore,directionalstabil- ity of vehicle would considerably degrade. Toprevent wheel lock-ups and their probable catastrophicconse- quences during severe braking, ABS has been intro- duced to automotive industry. The main idea in ABS is controlling the active brake torque so that prevents wheel lock-ups. This procedure results in generationofmaximumnegativeaccelerationofvehiclewhiletheRobustcontrolofwheelslipinanti-lockbrakesystemofautomobiles 127 directional stability and steering ability of vehicle isguaranteed[1].Inordertogeneratethemaximumnegativeacceler-ation of vehicle, the longitudinal force should bekept around its peak value which requires thefrictionforce to be at its peak amount [2].Researches show that thevalueofthefrictioncoefficientgreatlydependsonroad conditions. As shown in Fig. 1, the peakvalueoffrictioncoefficientvariesfrom0.02to0.43indifferentroad conditions[2].In general, two different strategies are used tocon- trol the braking torque in ABS for preventingwheel lock-ups. The first method is based on wheeldeceler- ation. In this method no information fromvehicle ve-locitysensorsisrequired.However,theoperatingloadfrom the road cannot be used completely in wheelde-celerationmethod.Thesecondmethoduseswheelslipratio, defined by the ratio of the difference betweenwheel linear velocity and vehicle speed over vehiclespeed. The second method uses the oil pressure inanactuatortoregulatethebrakingtorque.Thisregulation ispreformedasthewheelslipratiotracksapredefinedvalue regarding the friction coefficient peak valuein different road conditions [3,4].PI-controllers, which are commonly used in ABSof automobiles, require long time calibrationprocess and would not function effectively in thepresence of exogenous noises and disturbances.Furthermore, the performance of a PI controller isnot satisfactory robust to the vehicle brake modelsevere nonlineari-ties,structuredorunstructureduncertainties,andtime-varying dynamics due to variation of roadandvehicle conditions. Nowadays, regarding theadvancementsin microcomputer industry, theintelligent and adaptive controltechniquescouldbeimplementedinElectronicControl Units (ECU) of vehicles. Besides thesignif-128T. Sardarmehni etal. icant transient and steady-state performances, these controllers are adjusted simply and also are robust to the uncertainties[5].As the state of the art in the designing of ABSs, FLC and neural networks have been used. Regarding satisfactory transient and steady-state performance of the FLC in nonlinear time-varying systems, signifi- cantresearchhasbeenperformedonthesecontrolsys- tems.MauerdesignedaFLCsystemappliedonaquar- ter vehicle model which could identify different road conditions. The proposed FLC system could generate action brake signals through considering current and past values of the brake pressure and slip ratio [6]. Zhang et al. developed a FLC system by considering data to estimate vehicle speed. The estimated vehi- cle speed was used for predicting the amount of slip. Theproposedcontrollercalculatedthemodifiedbrake torque signal based on the predicted the amount of wheelslip[11].Jacquetetal.proposedaMPCsystem togeneratetheoptimalbraketorque.Theonlinerecon- structionwasdonebaseduponestimationofthebrake adhesion torque and estimation of the wheel speed. Furthermore, the necessity of wheel speed sensors for identifying the tire/road characteristics was avoided by using a torque sensor located in the wheel. The simulation results showed that the proposedcontroller had a fast and stable response under rapid changes of theroadconditions.Moreover,thedesignedcontroller dμ dμdλand ( dλ)/dt as inputs of the controller. The pro- posed FLC system led to better performance in pedal pushingfeeling[3].Sharkawydevelopedaself-tuning PID controller which was accompanied by Fuzzy and Geneticalgorithmtoobtaintheoptimalmodulesofthe designed FLC. The results showed that the proposed controller had a fast response with low overshoot and short stopping distance[7].As a model-based nonlinear control system, the Sliding Mode control (SMC) systems are preferred duetotheirfastandtheeaseoftheirapplicationonthenonlinear models. Besides the possibility of fast im- plementation, the robustness and the stability of SMC could be guaranteed in most applications [8]. There has been much research work on application of SMC systems in ABS. Harifi et al. designed a SMC sys- tem for ABS which used integral switching surface for reducing the chattering effects [9]. Half vehicle model was used so the designed controller provided two separated brake torques for front and rear wheel. Furthermore, the results of this controller were com- paredwiththoseofaFuzzy,aselflearningFuzzyslid- ing mode and a neural network hybrid controller. It wasstatedthatthedesignedcontrollerhadtheshortest stoppingdistance.However,theneuralnetworkhybrid controller had the least amount of wheel slip tracking error regarding to other controllers[9].Model Predictive Control (MPC) is a control tech- nique that tries to minimize the tracking errorthrough predictions of the future outputs of a plant which de- finesthepredictionhorizon[10].Duetotherobustand stable performance of this control system, it has al- ways attracted the attention of control engineers. An- war and Ashrafi presented a MPC system for ABS. The presented method required wheel speed sensors could satisfactorily shorten the stopping distance[1]. In this paper, half vehicle model is used for gen- erating the simulation data of a braking system. Two differentmodel-freecontroltechniquesincludingFLC andneuralnetworkMPCsystemsaredeveloped.Fora better assessment, the overall performance of the pro- posed FLC and MPC systems are compared. A neu- ral network-based algorithm is developed in the MPC system to generate the brake torque through track- ing a modified desired slip trajectory. In the MPC system, identification of the half vehicle brake sys- tem model is performed by a Multi-Layer Perceptron (MLP) neural network for the front wheel. In order to improve the identification error and cope with the se- vere time-varying dynamics of the vehicle brake sys- temmodel,asmalldatacollectionsampletimeisused for collecting the training patterns of the neural net- works.Inordertoincreasethecalculationspeedofthe MPC system, the brake system identification is per- formed by an offline MLP model. Training process of the MLP neural network model of the brake sys- tem is performed with offline data by Gradient De- scent Back-Propagation (GDBP) algorithm. In order toacceleratethecomputationsintheMPCsystem,the prediction horizon is shortened. To accelerate the op- timization and improve the robustness of the control system,adaptivestrategyisusedintheoptimizationof the MPC system. In the NPC system, an online MLP neural network is adaptively designed to generate the optimum values of brake torque such that predicted amount of slip in the NPC tracks its modified desired value. Here, GDBP algorithm is used for the online training of the MLP system in the controller. At the end,robustnessofthedesignedFLCandNPCsystems against modeling uncertainties and inputdisturbancesRobustcontrolofwheelslipinanti-lockbrakesystemofautomobiles 129 F = (m h + m h + m h) ⎪⎪ Fig. 2 Free-body diagramof the halfvehiclemodel[12]are evaluated by imposing 25 % Gaussian noises. Be- tweentheproposedmodel-freecontrolsystems,itwas seenthattheNPCsystemismorerobustthantheFLC system.Thesimulationresultsshowedthatthecontrol action input is a smooth signal in the designed NPC. The normal force can be considered as the difference between the vehicle mass distribution and mass trans- fer of the vehicle during acceleration or deceleration. The normal force due to vehicle mass distribution can be formulated as[12] Besides,thestoppingtimeanddistanceisshorterin ⎧ b the NPC system than the FLC controlsystem.The entire program is running in MATLAB/simu- linksoftware.⎪⎨F zf 1=a +b (m tot g) a ⎪⎩F zr 1=a +b (m tot g) (4)2 SystemdynamicsThe second part of the normal force on front wheel is obtainedfromusingtheconversionlawofmomenton rear wheel as[12] 2.1 A half vehicle dynamicmodelComprehensive vehicle models including all parame- ters are not control oriented models due to their com- plexity and highly nonlinearity. Therefore, a simpli- fied dynamical vehicle model that possesses all the (a +b)F zf 2=(m f h f +m s h s +m r h r )V ˙ Dividing both sides to (a + b ), onehas V ˙ zf 2 f f s s r r (a +b) (5) (6) main characteristics of vehicle systems isconsidered.A free-body diagram of the half vehicle model is shown in Fig.2.Applying the same procedure on the front wheels,the normal force of rear tire can be definedas V ˙ As shown in Fig. 2, steering effects and drag force are not considered in modeling to avoid complexity. The total traction force can be presented as[12] F tot = F xf +F xr (1) F zr 2=−(m f h f +m s h s +m r h r )(a +b) The normal forces of tires are defined as[12] ⎧F zf =F zf 1−F zf 2 ⎪⎪ (7) In(1),F xf and F xr are,respectively,thefrontandrear longitudinaltire-roadcontactforcesandaredefined ⎪⎪⎪ ⎨ b = a +b V ˙ m t g −(m f h f +m s h s +m r h r )(a +b) (8) as[12] ⎪⎪F zr =F zr 1−F zr 2 ⎪ F xf =μ(λf )F zf (2) ⎪⎪ a V ⎪⎪ ˙ F xr =μ(λr )F zr (3) where F zf and F zr arethenormalforcesactingonthe frontandrearwheel.μ(λf )and μ(λr )arefrictioncoef- ficientsbetweenroadandfront/reartires,respectively. ⎩ =a +b m t g +(m f h f +m s h s +m r h r )(a +b) Through some substitutions, the total traction force is obtained as[12] F tot =μ(λf )(m 1g −m 3V ˙)+μ(λr )(m 2g +m 3V ˙)(9)130T. Sardarmehni etal. ⎪ ⎩ ⎨ ⎪ 2J f ⎪⎪ ⎪ − Table 1 Constant values for different road condition [2] Road condition C 1 C 2 C 3where ⎧m 1=b m totand F zr in (14) and (15), angular acceleration for front wheel and rear wheel would be definedas 1 ⎪⎪ . . ⎪⎪ ⎨ m 2= ⎪⎪ a +b a a +btot(10)ω˙f =2J 1 −T bf +μ(λf )m 1gR −μ(λf )m 3R V ˙+T e (16) ⎪⎪⎪m 3= m f h f + m s h s +m r h ra +bω˙r = 2J r .T br +μ(λr )m 2gR +μ(λr )m 3R V ˙. (17) In (10), λ is the wheel slip which can be formulated for the front and rear wheel as[12]Since the main goal is controlling the wheel slip, the defined state variables in this paper are vehicle veloc- ity, the front and rear wheel slip (x 1 = V and x 2 =λf ⎧⎪λf = ⎪⎩λr = V −ωf RV V −ωr R V(11)and x 3 = λr ). Consequently, the state-space equations could be defined as[12] ⎧x ˙1=V ˙=f 1(x 2,x 3) ⎪ Wheel slip changes from 0 to 1 which indicatescom- pletelyrollingtireontheroadwithoutanyslipand⎪⎪⎪x ˙2 ⎪ =λ˙f bf wheel lock-up, respectively. Mostly, wheel lock-ups happen during deceleration while the angular veloc- ⎪⎪⎨ ⎪⎪ f 1(x 2,x 3)(1−x 2)−Rf 2(x 2,x 3)+RT = V (18) ity of wheels becomes zero. Burckhardt tire friction model is used to describe the relationship betweenthe ⎪⎪⎪x ˙3=λ˙r ⎪ RT br friction coefficient and wheel slip[2]:⎪⎪⎩ f 1(x 2,x 3)(1−x 3)−Rf 3(x 2,x 3)+ = V 2J r μ(λ) = C 1.1 − e −C 2λ.−C 3λ (12)where C 1, C 2 and C 3 are constants which depend on where ⎧ ⎪⎪f 1(x 2,x 3)=−g μ(x 2)m 1 +μ(x 3)m 2 roadcondition.Table 1showsthedifferentvaluefor ⎪⎪⎪ m tot 1 −μ(x 2)m 3 +μ(x 3)m 3 various roadconditions.By assuming the front wheel to be the driver one, the engine torque only acts on the front wheel. Free- body diagram of the Front-wheel is shown in Fig. 3. Applying Newton’s second law along the horizontal ⎨f 2(x 2,x 3)= ⎪⎪⎪ ⎪⎩f 3(x 2,x 3)= 2J f 1 2J r .μ(x 2)m 1Rg − μ(x 2)m 3Rf 1.(19) .μ(x 3)m 2Rg −μ(x 3)m 3Rf 1. direction one has[12]m tot V ˙=−F tot (13) 2J f ω˙f =−T bf +μ(λf )F zf R +T e (14) 2J r ω˙r =−T br +μ(λr )F zr R (15) In(14),T e representstheenginetorquewhichwould becomezeroduringdeceleration.Bysubstituting F zf 2.2 Dynamics of the hydraulic brakemodelThe structure of a standard hydraulic brake actuatoris shown in Fig. 4. There are two solenoid valves which can only be open or close. The amount of braking pressure is regulated through the opening conditionof each valve which is simply specified by coefficients C d1 and C d2. For instance, when C d1 = 1 and C d2 =0 f Dryasphalt 1.2801 23.99 0.52 Drycobblestones 1.3713 6.4565 0.6691 Dryconcrete 1.1973 25.168 0.5373 Wetasphalt 0.857 33.822 0.347 Wet cobblestones 0.4004 33.708 0.1204 Snow 0.1946 94.129 0.0646 Ice 0.05 306.39 0 Fig. 3 Front-wheel free-body diagram[12]Robustcontrolofwheelslipinanti-lockbrakesystemofautomobiles 131− = − Fig. 4 Structure of astandard hydraulicmodel[13]Fig. 5a Membershipfunction ofvelocitythe build valve is open and the dump valve is closed (see Fig. 4) which increases the braking pressure and vice versa. The hydraulic system dynamic model can be represented as[13]in this section. The parallel structure of FLC systems enables the control system to activate all rules simul- taneously. This characteristic of the FLC systems im- proves the required time for calculations[6]. In general, FLC systems perform four mainstages C dp i f dt ,2 = A 1C d1 ρ (P p −P i ) which are Fuzzification, rule base, inference mecha- nism and Defuzzification. Fuzzification andDefuzzi- −A 2C d2 ,2 (P i P low ) (20) ρ ficationstagestransformanynumericaldatatoitscor- responding fuzzy value and vice versa. The inferencemechanismdeterminesthematchingdegreeofthecur- Throughsomesimplifications,thebraketorquecanbe defined as[13] T b =P i A wc ηB F r r (21) It is assumed that the brake torque defined by (21), only acts on the driver wheel which is the front one. Theamountoftherearwheelbraketorqueisdepended on that of the front wheel and could be definedas T br =K br T bf (22) The value for K br is often selected to be less than 1 in order to prevent rear wheel lock-ups at the situations which front wheel locks-up[12]. 3 An ABS fuzzy controllerdesign Due to an acceptable performance of the FLC in non- linearsystems,thistypeofcontrolsystemisdevelopedrent fuzzy input with respect to each rule and decides which rules should be fired. At the end, the firedrules are combined to form the control action[14].Mamdani method is applied for designing a fuzzy controller for the front wheel. The input vector of the proposed controller is consisted of the vehicle speed, wheel slip error and oil pressure differences. The wheel slip error is the difference between the current wheel slip and the modified desired wheel slip which varies with the condition of the road. The wheel-slip errors of the front and rear wheel are definedas .e f λd λf (23) e r = λd −λrAs shown in Figs. 5a , 5b , 5c and 5d , six Gaussian membership functions are used for the vehicle speed. Moreover, seven Gaussian membership functions are usedforthewheelsliperror;fortheoilpressurediffer-encetwoS-shapemembershipfunctionsareused.De-130 T. Sardarmehni etal. Fig. 5b Membershipfunction of LambdaerrorFig. 5c Membershipfunction ofΔPFig. 5d Membershipfunction of C dTable 2a Positive pressure difference (ΔP >0) Table 2b Negative pressure difference (ΔP <0)Vλerror VλerrorNVB NB NS ZO PS PB PVB NVB NB NS ZO PS PB PVBVS DEC DEC DEC DEC INC INC INC VS DEC DEC DEC DEC INC INC INC S DEC DEC DEC DEC INC INC INC S DEC DEC DEC DEC INC INC INC M DEC DEC DEC DEC INC INC INC M DEC DEC DEC DEC INC INC INC B DEC DEC DEC DEC INC INC INC B DEC DEC DEC INC INC INC INC VB DEC DEC DEC DEC INC INC INC VB DEC DEC DEC INC INC INC INC VVB DEC DEC DEC DEC INC INC INC VVB DEC DEC DEC INC INC INC INCfuzzification is performed through two Z-shapemem- bershipfunctions.After defining fuzzy sets for inputs and output, fuzzy control rules are designed as described in Ta- bles2a and 2b. Fuzzy control rules are developed for two different positive and negative oil pressurediffer- ence situations. In Tables 2a and 2b, INC represents the command that opens the build valve and closes the dump valve and DEC expresses the commandthat closesthebuildvalveandopensthedumpvalve. 4MultiLayerPerceptron(MLP)modelingofthe brakesystem4.1Structure of the MLP neuralnetworkThe structure of a MLP neural network is shown in Fig. 6. The proposed neural network model of the brake system is consisted of two layers comprising hidden layer and output layer. The input data are re-ceivedanddistributedtothenodesofthehiddenlayer.132T. Sardarmehni etal. 2 2 × f W (i,1) W 1 W (j,1) Fig. 6 Block diagram ofMLP neuralnetworksThe nonlinear activation function, f 1 in everyneuronofthehiddenlayerreceivestheweightedsumofallin-putdataplusthebiastermofeachcorrespondingnode.Intheoutputlayer,theweightedoutputsofthehidden layerarelinearlysummeduptotheoutputlayer’sbiaswhere Q is the total number of training patterns and l defines the in-process training pattern. Based on the back propagation algorithm, the bias term of (27) is updatedas ∂E(k) term and form the output of thenetwork.b 2(k +1)=b 2(k)−η ∂b 2(30) Assuming the number of inputs as p , the numberof neurons in the hidden layer as q and the dimen-sion of the network’s output as 1, the attributes ofthewhere η is a small positive number called thelearning rate. More precisely, it can beshown Q neural network model become as W 1 R q ×p ,b 1R q ×1,2 2 .∂E(k) ∂y(l) net 1 R q ×1, a 1 R q ×1, W 2 R q ×1 and b 2 R 1×1.Theactivationfunction f 1isasigmoidfunctiondefinedas 2b (k + 1) = b (k) −η = b (k) −η l =1 Q . ∂y(l)∂b 2(k) e l (l) (31) f 1(x)=1 +exp (−βx) − 1 (24)l =1 The same procedure can be performed for updating where 0 < β <1 is a tuning parameter and could beadjusted by experience or trial and error. Now, theweightedinputvector,P isgatheredwiththeneuron’sW 1, W 2, and b 1. So onehas W 2(k +1) Q bias term to obtain net 1as= W (k) −η .∂E(k) ∂y(l) 2 net 1 = W 1P +b 1 (25)l =1 Q ∂y(l) ∂W (k) Therefore, the output of the hidden layer, a 1 isob-2 . 1. 1 1. tainedasa 1 =f .net 1. (26)= b (k) −η b 1 l =1 e l (l)f W P (l) +b (32)The network’s overall output can now be obtained asfollows [10, 15,16]:(i,1)(k +1) =b 1 Q ..l (1,i) y = W 2a 1 +b 2 (27)(i,1)(k) −η l =1 e (l) ×W 2 (k) r .1 (i,j) (k)P (i,1)(l)+b 1 (k).. (33) 4.2 Training algorithm of the MLPnetworkThe parameters of MLP model, including b 1, b 2,W 1And similarly, onehas (j,i)(k +1) Q . and W 2,areupdatedbytheGDBPalgorithmbasedonthefollowingerror,e l :e l = y −y d (28)= W 1 (k) (j,i) .p −η.e l (l)W 2f r j l =1 .where y and y d are the MLP’s and desired outputs,respectively.Theindexofperformancecanbedefined..1 × (j,i) i =1 . (k)P (i,1)(l)+b 1 (k). as×P (j,1)(l) 1 Q (34) .. .E =2l =1y(l)−y d (l) (29)Comprehensive details and formulation of GDBP al- gorithm can be found in [10, 15,16].Robustcontrolofwheelslipinanti-lockbrakesystemofautomobiles133Fig. 7a Illustration ofnormalized brake torqueused fortrainingFig. 7b Illustration ofnormalized slip ratio usedfortraining4.3 The MLP model training and validationdataFor the front wheel, an MLP neural network istrainedby the GDBP algorithm. Considering λ(t) as the out-put slip of each MLP network at the current sampletime, t , the input vector of the training process is con-sistedofthebraketorqueandtheslipat(t −1)and(t ) as P = .T b (t), T b (t − 1), λ(t − 1), λ(t −2).T (35)ThroughwidespreadsimulationdataoftheMLPbrakesystem model, four neurons are chosen in the hid-den layer and thereby the neural network parame-ters are specified as W 1 R 4×4, b 1 R 4×1, W 2 R 4×1and b 2 R 1×1. A 4000-tuple random signal of braketorque, which was bounded to the interval 400 to5000 (Newton-meter), is imposed to the brakesystemmodel. To consider both the transient and the steady-state performance of the brake system, one half ofthe training patterns are generated with pulse widthof0.1 second and the other half has a wide pulse width,1.5 second. By imposing the input training data onthe brake system, 4000 output values for slip are gen-erated, which are used in the training process of the neural network systems. As Figs. 7a and 7b show, all trainingpatternsarenormalizedintotheinterval [0,1]. A fixed 0.01 second sample time is used in the gener- ation of the training data. β in (24) is considered2. In training with GDBP, the learning rate is set to 0.001. The initial values for weights and biases were taken as random numbers. The training process was finished when all errors (29) of the training patterns reached 0.01. The training process with GDBP was performedin458.25seconds.Aftertraining,theaccu- racy of the trained MLP model is evaluated by a new set of bounded random samples for the brake torque. Theresulted0.0026MeanAbsoluteError(MAE)cor- responding to the evaluation data in Fig. 8is signifi- cantlysmall. TheconvergedweightandbiasesoftheMLPneural network models for the front wheel are presented in Table 3. 5 MPC The schematic of the proposed NPC system is shownin Fig. 9. In each sample time, the NPC generates N u134T. Sardarmehni etal.⎢ ⎢ ⎢ ⎥⎥Fig. 8 Illustration ofvalidationdataMAE =0.0026Fig. 9 Schematic of NPCsystemTable 3 Final parameters of the MLPmodel⎡0.1791 ⎤ T ⎡0.4025 ⎤ ⎡ 0.2504 −0.1039 0.08790.4792 ⎤ ⎢0.6155 ⎥⎢0.6992 ⎥ ⎢ 0.1193 −0.1287 0.74980.4613 ⎥ b 1=⎢− ⎥ b 2 =−0.0847 W 2 =⎢ ⎥ W 1 =⎢ ⎥ 0.4755 ⎥ −0.2207⎥ ⎢0.6112 0.5432 0.7971 0.5464⎥ ⎣ ⎦1.1208 ⎣ ⎦ 0.6099 ⎣ ⎦ 0.4545 0.3086 0.8599 0.8654number of future constrained control inputs such thatthe predicted amount of system output tracks a modi-fied desired trajectory throughout the prediction hori-zon. N u defines the predictionhorizon.InFig.9,T b (t 0)and λ(t 0)showthebraketorqueand the slip at time t 0, respectively. Therefore, in thetime interval t 0 through t 0+Δt , all the components ofthe following vector, P i are known for i =0: P i =.T b (t 0 +iΔt),T b .t 0 +(i −1)Δt .,λ.t 0+(i −1)Δt .,λ.t 0+(i −2)Δt ..Ti =0,..., N u (36)In the NPC system, the vector P i is given to the MLPmodel of the brake system for predicting the slip.Therefore,intheinterval,t 0to t 0+Δt ,NPCrequiresthe predicted values of T b and λ at time samples t 0 + iΔt (i = 0,..., N u ). The values of λ(t 0 + iΔt) for each P i in Fig. 9is predicted through the trained MLP model of the brake system using P i −1 for i = 1,..., N u . The optimal values of T b (t 0 + iΔt) are obtained through the optimization process fully discussed in Sect.5.1. Theonlineoptimizationresultsinoptimizedvalues of all U i s in each sample time. As shown in Fig. 9, only the first component of P 1, which is shown as U 1,is used as the control input. Similarly, the remain- ing U i s are considered as the initial values for the fu- ture time steps, recursively. This usage of the preced- ing optimized values as the initial values of the cur- renttime results in fast convergence of the NPC sys- tem.Robustcontrolofwheelslipinanti-lockbrakesystemofautomobiles135 2 = − (j,1) = − + = − = − 1 + = 1 − 1 W W ∂Ψ (k) 2 W (j,1) (i,1) . f 5.1 OptimizationForreducingthecalculation’stimecostandimproving therobustnessoftheMPCsystem,optimizationunitis constructedbasedonMLPneuralnetworks.Inthepro- and ∂U 1(k) ∂Φ2(k) =1 (44) Similarly, ψ 2 is updatedas posedoptimizationmethod,anMLPneuralnetworkis adaptivelytrainedtogeneratetheonlineoptimumval- ues for control actions. These optimal control actions aregeneratedbasedonthetrackingperformanceofthe slip in the MPCsystem.As a result, an MLP neural network with thesame Ψ2(k +1)=Ψ2(k)−η∂E(k) ∂Ψ(k) From chain rule, (45) simplifiesto Ψ 2(k +1) Ψ 2(k) η∂E(k) ∂e l (k) ∂λ1(k)∂U 1(k) ∂e l (k) ∂λ1(k) ∂U 1(k) ∂Ψ2(k) (45) (46) structuregiveninSect.4.1isusedforanonlinegener- ation of front wheel brake torque signal. Considering ψ 1 and ψ2 as the first and second layer weightmatri- ces, and ϕ1 and ϕ2 as the first and second layer bias terms, the output can be definedaswhere: ∂U 1(k) ∂Ψ2(k) 4 ..4 .. U 1=Ψ2g .Ψ1X 0+Φ1.+Φ2 (37) = g i =1 . j =1 1 (i,j) X 0(j,1)+Φ1 (47) where g is the activation function defined by (24) for β = 2. For N u = 1, the error terms can be definedas According the GDBP algorithm, Φ1 could be updated as 1 1 ∂E(k) e l = λ(1)−λd (1) (38) where λ(1) is definedasλ(1) = W 2f 1.W 1X 1 + b 1.+b 2 (39)Φ (k + 1) = Φ (k)−η∂Φ1(k) (48) We apply the chain rule andwrite Φ1(k +1) The error term is definedas Φ1(k) η∂E(k) ∂e l (k) ∂λ1(k)∂U 1(k) ∂e l (k)∂λ1(k)∂U 1(k)∂Φ1(k) (49) 1 2with E = 2e l (40) ForonlineupdatingoftheparametersoftheMLPnet- work, back propagation algorithm is used. Hence,one ∂U 1(k) ∂Φ1(k) 4 . .4 .. has = .Ψ 2 r .(i,j)X 0(j,1)+Φ(j,1) Φ2(k 1) Φ2(k) η∂E(k)∂Φ2(k)(41)i =1 (i,1)g Ψ1 j =1 1 (50) We use the chain rule to rewrite (40)as Φ2(k +1) Φ2(k) η∂E(k) ∂e l (k) ∂λ1(k)∂U 1(k)∂e l (k)∂λ1(k)∂U 1(k)∂Φ2(k)(42)By the same procedure ψ1 can be updatedas ∂E(k) Ψ (k 1) Ψ (k) η ∂Ψ1(k) We use the chain rule toobtain Ψ 1(k +1) (51) The first two partial derivative terms on the rightside of(42)areeasilydefinedandthethirdtermcanbe =Ψ1(k)−η∂E(k)∂e l (k)∂λ1(k)∂U 1(k) (52) formulatedas4 .where ∂e l (k) ∂λ1(k) ∂U 1(k)∂Ψ (k) ∂λ1(k) ∂U 1(k)= .i =1 2 (1,i) 1 r(i,1) ∂U 1(k ) 1 (i,j) = Ψ (i,1)X 0(i,1)g r .4. × j =11 (i,j) ..X 1(j,1)+b 1 (43).4 . × j =1 1 (i,j) . X 0(j,1)+Φ1 (53) Ψ Ψ。

中英文文献翻译-汽车制动系统简介

附录AAutomobile Brake SystemThe braking system is the most important system in cars. If the brakes fail, the result can be disastrous. Brakes are actually energy conversion devices, which convert the kinetic energy (momentum) of the vehicle into thermal energy (heat).When stepping on the brakes, the driver commands a stopping force ten times as powerful as the force that puts the car in motion. The braking system can exert thousands of pounds of pressure on each of the four brakes.Two complete independent braking systems are used on the car. They are the service brake and the parking brake.The service brake acts to slow, stop, or hold the vehicle during normal driving. They are foot-operated by the driver depressing and releasing the brake pedal. The primary purposeof the brake is to hold the vehicle stationary while it is unattended. The parking brake is mechanically operated by when a separate parking brake foot pedal or hand lever is set. The brake system is composed of the following basic compon ents: the “master cylinder” which is located under the hood, and is directly connected to the brake pedal, converts driver foot’s mechanical pressure into hydraulic pressure. Steel “brake lines” and flexible “brake hoses” connect the master cylinder to the“slave cylinders” located at each wheel. Brake fluid, specially designed to work in extreme conditions, fills the system. “Shoes” and“pads” are pushed by the slave cylinders to contact the “drums” and “rotors” thus causing drag, which (hopefully) slows the car.The typical brake system consists of disk brakes in front and either disk or drum brakes in the rear connected by a system of tubes and hoses that link the brake at each wheel to the master cylinder (Figure).Basically, all car brakes are friction brakes. When the driver applies the brake, the control device forces brake shoes, or pads, against the rotating brake drum or disks at wheel. Friction between the shoes or pads and the drums or disks then slows or stops the wheel so that the car is braked.In most modern brake systems (see Figure 15.1), there is a fluid-filled cylinder, called master cylinder, which contains two separate sections, there is a piston in each section and both pistons are connected to a brake pedal in the driver’s compartment. When the brake is pushed down, brake fluid is sent from the master cylinder to the wheels. At the wheels, the fluid pushes shoes, or pads, against revolving drums or disks. The friction between the stationary shoes, or pads, and the revolving drums or disks slows and stops them. This slows or stops the revolving wheels, which, in turn, slow or stop the car.The brake fluid reservoir is on top of the master cylinder. Most cars today have a transparent r reservoir so that you can see the level without opening the cover. The brake fluid level will drop slightly as the brake pads wear. This is a normal condition and no cause for concern. If the level drops noticeably over a short period of time or goes down to about two thirds full, have your brakes checked as soon as possible. Keep the reservoir covered except for the amount of time you need to fill it and never leave a cam of brake fluid uncovered. Brake fluid must maintain a very high boiling point. Exposure to air will cause the fluid to absorb moisture which will lower that boiling point.The brake fluid travels from the master cylinder to the wheels through a series of steel tubes and reinforced rubber hoses. Rubber hoses are only used in places that require flexibility, such as at the front wheels, which move up and down as well as steer. The rest of the system uses non-corrosive seamless steel tubing with special fittings at all attachment points. If a steel line requires a repair, the best procedure is to replace the compete line. If this is not practical, a line can be repaired using special splice fittings that are made for brake system repair. You must never use copper tubing to repair a brake system. They are dangerous and illegal.Drum brakes, it consists of the brake drum, an expander, pull back springs, a stationary back plate, two shoes with friction linings, and anchor pins. The stationary back plate is secured to the flange of the axle housing or to the steering knuckle. The brake drum is mounted on the wheel hub. There is a clearance between the inner surface of the drum and the shoe lining. To apply brakes, the driver pushes pedal, the expander expands the shoes and presses them to the drum. Friction between the brake drum and the friction linings brakes the wheels and the vehicle stops. To release brakes, the driver release the pedal, the pull back spring retracts the shoes thus permitting free rotation of the wheels.Disk brakes, it has a metal disk instead of a drum. A flat shoe, or disk-brake pad, is located on each side of the disk. The shoes squeeze the rotating disk to stop the car. Fluid from the master cylinder forces the pistons to move in, toward the disk. This action pushes the friction pads tightly against the disk. The friction between the shoes and disk slows and stops it. This provides the braking action. Pistons are made of either plastic or metal. There are three general types of disk brakes. They are the floating-caliper type, the fixed-caliper type, and the sliding-caliper type. Floating-caliper and sliding-caliper disk brakes use a single piston. Fixed-caliper disk brakes have either two or four pistons.The brake system assemblies are actuated by mechanical, hydraulic or pneumatic devices. The mechanical leverage is used in the parking brakes fitted in all automobile. When the brake pedal is depressed, the rod pushes the piston of brake master cylinder which presses the fluid. The fluid flows through the pipelines to the power brake unit and then to the wheel cylinder. The fluid pressure expands the cylinder pistons thus pressing the shoes to the drum or disk. If the pedal is released, the piston returns to the initial position, the pull back springs retract the shoes, the fluid is forced back to the master cylinder and braking ceases.The primary purpose of the parking brake is to hold the vehicle stationary while it is unattended. The parking brake is mechanically operated by the driver when a separate parking braking hand lever is set. The hand brake is normally used when the car has already stopped. A lever is pulled and the rear brakes are approached and locked in the “on” position. The car may now be left without fear of its rolling away. When the driver wants to move the car again, he must press a button before the lever can be released. The hand brake must also be able to stop the car in the event of the foot brake failing. For this reason, it is separate from the foot brake uses cable or rods instead of the hydraulic system.Anti-lock Brake SystemAnti-lock brake systems make braking safer and more convenient, Anti-lock brake systems modulate brake system hydraulic pressure to prevent the brakes from locking and the tires from skidding on slippery pavement or during a panic stop.Anti-lock brake systems have been used on aircraft for years, and some domestic car were offered with an early form of anti-lock braking in late 1990’s. Recently, several automakers have introduced more sophisticated anti-lock system. Investigations in Europe, where anti-lock braking systems have been available for a decade, have led one manufacture to state that the number of traffic accidents could be reduced by seven and a half percent if all cars had anti-lock brakes. So some sources predict that all cars will offer anti-lock brakes to improve the safety of the car.Anti-lock systems modulate brake application force several times per second to hold the tires at a controlled amount of slip; all systems accomplish this in basically the same way. One or more speed sensors generate alternating current signal whose frequency increases with the wheel rotational speed. An electronic control unit continuously monitors these signals and if the frequency of a signal drops too rapidly indicating that a wheel is about to lock, the control unit instructs a modulating device to reduce hydraulic pressure to the brake at the affected wheel. When sensor signals indicate the wheel is again rotating normally, the control unit allows increased hydraulic pressure to the brake. This release-apply cycle occurs several time per second to “pump” the brakes like a driver mig ht but at a much faster rate.In addition to their basic operation, anti-lock systems have two other things in common. First, they do not operate until the brakes are applied with enough force to lock or nearly lock a wheel. At all other times, the system stands ready to function but does not interfere with normal braking. Second, if the anti-lock system fail in any way, the brakes continue to operate without anti-lock capability. A warning light on the instrument panel alerts the driver when a problem exists in the anti-lock system.The current Bosch component Anti-lock Braking System (ABSⅡ), is a second generation design wildly used by European automakers such as BWM, Mercedes-Benz and Porsche. ABSⅡsystem consists of : four wheel speed sensor, electronic control unit and modulator assembly.A speed sensor is fitted at each wheel sends signals about wheel rotation to control unit. Each speed sensor consists of a sensor unit and a gear wheel. The front sensor mounts to thesteering knuckle and its gear wheel is pressed onto the stub axle that rotates with the wheel. The rear sensor mounts the rear suspension member and its gear wheel is pressed onto the axle. The sensor itself is a winding with a magnetic core. The core creates a magnetic field around the winding, and as the teeth of the gear wheel move through this field, an alternating current is induced in the winding. The control unit monitors the rate o change in this frequency to determine impending brake lockup.The control unit’s function can be divi ded into three parts: signal processing, logic and safety circuitry. The signal processing section is the converter that receives the alternating current signals form the speed sensors and converts them into digital form for the logic section. The logic section then analyzes the digitized signals to calculate any brake pressure changes needed. If impending lockup is sensed, the logic section sends commands to the modulator assembly.Modulator assemblyThe hydraulic modulator assembly regulates pressure to the wheel brakes when it receives commands from the control utuit. The modulator assembly can maintain or reduce pressure over the level it receives from the master cylinder, it also can never apply the brakes by itself. The modulator assembly consists of three high-speed electric solenoid valves, two fluid reservoirs and a turn delivery pump equipped with inlet and outlet check valves. The modulator electrical connector and controlling relays are concealed under a plastic cover of the assembly.Each front wheel is served by electric solenoid valve modulated independently by the control unit. The rear brakes are served by a single solenoid valve and modulated together using the select-low principle. During anti-braking system operation, the control unit cycles the solenoid valves to either hold or release pressure the brake lines. When pressure is released from the brake lines during anti-braking operation, it is routed to a fluid reservoir. There is one reservoir for the front brake circuit. The reservoirs are low-pressure accumulators that store fluid under slight spring pressure until the return delivery pump can return the fluid through the brake lines to the master cylinder.附录B汽车制动系统制动系统是汽车中最重要的系统。

(完整版)汽车制动系统-英文文献及翻译

Brake systemsWe all know that pushing down on the brake pedal slows a car to a stop. But how does this happen？How does your car transmit the force from your leg to its wheels？ How does it multiply the force so that it is enough to stop something as big as a car?Brake Image GalleryLayout of typical brake system. See more brakeimages。

When you depress your brake pedal， your car transmits the force from your foot to its brakes through a fluid. Since the actual brakes require a much greater force than you could apply with your leg， your car must also multiply the force of your foot. It does this in two ways：•Mechanical advantage (leverage)•Hydraulic force multiplicationThe brakes transmit the force to the tires using friction， and the tires transmit that force to the road using friction also。

Before we begin our discussion on the components of the brake system, we’ll cover these three principles:•Leverage•Hydraulics•FrictionLeverage and HydraulicsIn the figure below, a force F is being applied to the left end of the lever. The left end of the lever is twice as long (2X) as the right end （X）。

汽车专业外文翻译(英文+译文)

原文：Routine brake system maintenanceThe braking system is the most important system on a car. If the brakes don't work properly, the result can be disastrous. So the good brakes are essential for safety.There are two completely independent braking systems on a car. One is the service brake, and the other is parking brake. The service brake acts to slow, stop, or hold the vehicle during normal driving. They are foot-operated by the driver depressing and releasing the brake pedal. The parking brake's purposes are to hold a car stationary while it is unattended, and to keep the car from rolling on unleveled ground. It is also called the handbrake.Basically, all car brakes are friction brakes. When the driver applies the brake, the control device will force brake shoes or pads against the rotating brake drums or discs at wheels. Friction between the shoes or pads and the drums or disks then slows or stops the wheels so that the car is braked.Disc brakeDisc brakes are used on the front wheels of most cars and on all four wheels on many cars.The main components of a disc brake are the brake pads, the caliper which contains a piston, and the rotor which is mounted to the hub.The disc brake is a lot like the brakes on a bicycle. Bicycle brakes have a caliper, which squeezes the brake pads against the wheel. In a disc brake, the brake pads squeeze the rotor instead of the wheel, and the force is transmitted hydraulically instead of through a cable. Friction between the pads and the disc slows the disc down.A moving car has a certain amount of kinetic energy, and the brakes have to remove this energy from the car in order to stop it. The brakes convert the kinetic energy to heat generated by the friction between the pads and the disc, so the car stops.Drum brakeSo if disk brakes are so great, how come we still have cars with drum brakes? The reason is cost. While all most vehicles for many years have disk brakes on the front wheels, drum brakes are cheaper to produce for the rear wheels. Drum brake is shown in Fig.Drum brakes consist of a backing plate, brake shoes, brake drum, wheel cylinder, return springs and an automatic or self-adjusting system. When you apply the brakes, the wheel cylinder pushes the brake shoes into contact with the machined surface on the inside of the drum. When the pressure is released, return springs pull the shoes back to their rest position. As the brake linings wear, the shoes must travel a greater distance to reach the drum. When the distance reaches a certain point, a self-adjusting mechanism automatically reacts byadjusting the rest position of the shoes so that they are closer to the drum.Hydraulic Brake SystemsWhen the operator steps on the brake pedal, the brake pedal operates a hydraulic system.The typical brake system is composed of the following basic components(1) Master cylinder. That is directly connected to the brake pedal, converts your foot's mechanical pressure into hydraulic pressure.(2) Brake lines and brake hoses, they connect the master cylinder to the wheel cylinders located at each wheel.(3) Brake fluid: that is special oil that has special properties. It is designed to withstand cold temperature without thickening as well as very high temperature without boiling.In the brake system, master cylinder contains two separate sections, there is a piston in each section and both pistons are connected to a brake pedal in the driver's compartment. When the brake is pushed down, brake fluid is sent from the master cylinder to the wheels. At the wheels, the fluid pushes shoes, or pads, against revolving drums or disks, which can slow and stop car. This slows or stops the revolving wheels, which, in turn, slow or stop the car.Routine maintenance of automobile brake fluid: Usually brake fluid maintenance period of 2 years or 48,000 km. Recommended brake fluid on the maintenance period, the European car manufacturers generally set a few years; and Japan and the United States car manufacturers are generally in their owner's manual have detailed descriptions. The abs function with anti-lock braking system, brake fluid and timely supplement is especially important. This is mainly due to energy storage in the pollution of dust and moisture of the body will lead to expensive failure, and thus laid security risk when vehicle braking force owners to find weak, you can use brake fluid test strips humidity assisted analysis of whether there is any fault of defect caused by brake fluid. If the brake fluid for the failure of the root causes of lack of sufficient quantity to be added in time brake fluid. By the brake fluid tank vent in a normal infiltration (or when tank lid open non-regular access to) the moisture and dust reduced brake fluid maintenance cycle. Maintenance of the brake fluid in the same time, must not neglect the wheel brake parts.Auto brake pad, brake drum, rotating body, and brake calipers: the current drive vehicle for leading the trend, people are concerned about how to play the 2 / 3 of the front brake lines brake tasks for scientific and effective maintenance. Now, after a variety of drive, all-wheel drive, trucks and suv blossom everywhere, people "before re-light after the" traditional concept has gradually changed.Gradually replace the asbestos linings in the semi-metallic brake pad will cause the whole surface of rotating serious wear and tear. Brake parts on the car wheel or brake pad inspection is a complex task, not simply from a visual look at both sides of the front brakepads wear the middle point. In actual operation, even if the brake caliper of open distance just to let you see both sides of the brake pad, it does not mean we can be handy, unimpeded operation of the. In addition, the popularization of brake shield, and the brake pad of rotating the contact surface is multi-block, hard look. As for the rear wheel with disc brake, it is hidden, is difficult to comprehend the appearance.Typically, the only system in the apparent leak, we will focus on checking brake fluid sealing. The comprehensive system of inspection, including the traditional static checking (that is, to find leaks in situ static) and dynamic checks (ie check the seal during braking). In any case, when the vehicle braking system to maintain up to 48 000 km driving range, they need the vehicle's braking system to conduct a comprehensive professional maintenance Brake rotating body of minor scratches do not cause illness. But since the fastening nut tightening force thickness of inequality and uneven brake rotating body rotation caused by excessive wear and tear will seriously affect the braking performance. To reduce weight, many rotating body size using unconventional structure, which is difficult to meet some of the machine tool clamping the basic requirements. If you find a rotating body has been processed, then follow the same axle of the second rotating body is only the size of its replacement. In theory, you can only replace a rotating body, but to get the best balance between braking effect, or the proposed replacement with two on the same axle rotating body. The proposal also applies to vehicles during braking, brake caliper piston through the experience back movement, we can complete the key features of the automatic brake calipers inspection. If the brake caliper piston back position is unsound, please replace a new brake caliper; If you want to discharge or filling brake fluid, make sure relief valve can be normally open; if the relief valve setting, replace the new The brake caliper.If the asbestos linings have worn 3.175mm, this time even under light loading, the security of driving range has also been very limited. Also, if needed at this time of high load brake, the wear lining weak braking force will make the traffic safety compromised.Some rear disc brake, rear-drive rotary body with a cap, the cap body also acts as a rotary brake drum. There are many car owners often overlook the parking brake will cancel the direct-drive vehicles, the rotating body and the brake shoes in direct metal - metal friction, the result is bound to cause a rotating body, brake pads and brake shoes of serious wear and tear.译文：汽车制动系统的日常维修保养制动系统是汽车上最重要的系统。

车辆工程专业英语词汇

车辆工程专业英语词汇汽车工程专业英语词汇1. Engine - 引擎2. Transmission - 变速器3. Suspension - 悬架系统4. Brake - 制动器5. Chassis - 底盘6. Exhaust - 排气系统7. Fuel injection - 燃油喷射系统8. Steering - 转向系统9. Ignition - 点火系统10. Hybrid - 混合动力11. Battery - 电池12. Alternator - 发电机13. Turbocharger - 涡轮增压器14. Radiator - 散热器15. Cylinder - 汽缸16. Piston - 活塞17. Crankshaft - 曲轴18. Camshaft - 凸轮轴19. Valve - 气门20. Timing belt - 正时皮带21. Clutch - 离合器22. Differential - 差速器23. ABS (Anti-lock Braking System) - 防抱死制动系统24. ECU (Engine Control Unit) - 发动机控制单元25. OBD (On-board Diagnostics) - 车载诊断系统26. CVT (Continuously Variable Transmission) - 连续可变传动系统27. DSG (Direct-Shift Gearbox) - 双离合器变速器28. Traction control - 牵引力控制系统29. ESC (Electronic Stability Control) - 电子稳定控制系统30. Airbag - 安全气囊。

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具有道路识别的车轮速度传感器防抱死制动系统Road Identification for Anti-Lock Brake SystemsEquipped with Only Wheel Speed Sensors摘要：防抱死制动系统（ABS）目前在机动车辆上广泛使用。

为了降低成本，在目前可用的技术中，标准的ABS轮速传感器不能由控制单元直接测得所需要的车轮滑移率，但可以用来测量车轮角速度和计算车辆滑移率。

因此，路面的附着系数决定了车辆减速制动，是估计车辆的速度的一个重要参数。

本文分析了重型汽车在不同路面上制动模拟车轮加速度反应和选择对特定的点来确定每个操作条件下车轮加速度曲线，如路面，踏板扭矩和车轮垂直载荷制动。

曲线使用选定的点在每个路面明显不同。

因此，不同的路面选定的点代表他们的相应的道路表面。

分析认为，只有车轮速度传感器作为硬件和道路衔接条件可以确定车辆在剧烈的制动过程的初始速度。

Abstract :Anti-lock brake systems (ABS) are now widely used on motor vehicles .To reduce cost and to use currently available technologies ,standard ABS uses only wheel speed sensors to detect wheel angular velocities ,which is not enough to directly obtain wheel slip rations needed by the control unit ,but can be used to calculate reference slip ratios with measured wheel angular velocities and the estimated vehicle speed .Therefore ,the road friction coefficient, which determines the vehicle deceleration during severe braking , is an important parameter in estimating vehicle speed .This paper analyzes wheel acceleration responses in simulations of severe braking on different road surfaces and selects a pair of specific points to identify the wheel acceleration curve for each operating condition ,such as road surface , pedal-braking torque and wheel vertical load .It was found that the curve using the selected points for each road surface clearly differs from that of the other road surface. Therefore, different road surfaces can be distinguished with these selected points which represent their corresponding road surfaces. The analysis assumes that only wheel speed sensors are available as hardware and that the road cohesion condition can be determined in the initial part of the severe braking process.关键词：防抱死制动系统（ABS）；道路识别；车轮角加速度；轮胎的特点Key words: anti-lock brake systems (ABS); road identification; wheel angular acceleration; tire characteristics简介Introduction防抱死制动系统（ABS），道路衔接条件是最重要的因素之一。

制动时标准的ABS可以识别道路摩擦高（沥青）或低（雪，冰）来决定衔接条件，使控制单元激活相应的控制逻辑，ABS轮速传感器能有效的识别道路条件。

道路识别研究是当前汽车控制的一个热门话题，研究人员通常假设除了车轮速度传感器外其它的设备也可以测量车辆运动等状态参数，以连续监测道路条件。

但标准的ABS 只需要确定初始制动期间的道路条件，然后获取道路信息来确定控制单元所需的操作。

明显的，因为硬件成本的原因，合格的ABS道路识别不是特别精确。

而且确定道路条件的方法是不特别明显。

本文研究了ABS的标准配置的道路识别方法。

For anti-lock brake systems(ABS),the road cohesion condition is one of the most important factors .Standard ABS can identify road cohesion conditions while braking and decide whether the road friction is high (asphalt) or low (snow , ice),so that the control unit activates the corresponding control logic . Only wheel speed sensors are available in standard ABS to identify the road conditions, with no other sensors needed. Road identification research is currently a popular topic in automotive control, but researchers usually assume extra equipment is available for measuring vehicle motion and other state parameters besides wheel speed sensors, to continuously monitor the road condition. But standard ABS only needs to identify road conditions during the initial braking period, and then obtain road information to ensure necessary operations of the control unit. Obviously, the standard ABS demands less strict identification, therefore less hardware and cost. However, the method to identify the conditions is not obvious. This paper investigates the road identification method for the standard ABS configurationn.该分析是基于车轮角加速度，从测得的车轮角速度所获得的。

由于轮胎对路面摩擦特性不同使得车轮在不同路面上的反应不同，在不同的路面制动也不同，所以轮响应必须包含道路衔接信息。

因此，我们选择两种典型的车轮加速度曲线来模拟在制动时不同的路面下的制动情况。

将测量中的不确定性因素造成的的影响进行了讨论。

The analysis is based on the wheel angular acceleration, which is acquired from the measured wheel angular speed. Since tire-road friction characteristics differ on different road surfaces, the wheel responses while braking on different surfaces are also different, so the wheel responses must contain road cohesion information. Therefore, we simulated braking situations and then chose two typical values on the wheel acceleration curve as criteria to distinguish between different road surfaces. Influence of uncertainties in the measurements is also discussed.建模1 Modeling 11/4的汽车模型（图1）是Dugoff轮胎模型。

轮胎的摩擦曲线的峰值（即，凝聚系数）在不同的路面上不同，如干燥沥青0.8-0.9湿沥青，0.5-0.7，雪和冰的约0.2和0.1。

此外，当滑移率呈正增长时，摩擦系数以不同的速率增加。

在冰雪路面上摩擦系数增长的速率远远低于沥青路面。

摩擦系数达到最大值是控制单元确定道路条件重要信息。

一旦摩擦系数接近最大值，控制单元开始调节制动压力。

一般来说，在沥青路面上随着滑移率的增加，摩擦系数增加率至少是冰雪路面的一倍。

为了反映这种差异，在特征曲线上沥青路面的初始斜率是雪冰路面的两倍。

如果这种差异变的更大，则假设的结果会更有效。

A one quarter vehicle model (Fig.1) is used with the Dugoff tire model. The peak values of the tire slip-friction curve (i.e., cohesion coefficient) are different for different road surfaces, such as dry asphalt 0.8-0.9, wet asphalt 0.5-0.7, snow about 0.2 and ice about 0.1.Furthermore, when the slip ratio increases above zero, the friction coefficient increases at a different rate. This is especially true for the increase of the friction coefficients on snow or ice which are much lower than on asphalt. This feature is important since the control unit makes decisions about road conditions before the friction coefficient reaches a maximum .Once the friction coefficient is close to the maximum, the control unit starts to regulate the braking pressure.Generally, the friction coefficient rate of increase with the increasing slip ratio on asphalt is at least double that on snow or ice. To reflect this difference, the initial slope of the characteristic curve on asphalt was assumed to be twice that of snow. If the difference is even greater, the results using the assumption will be even more effective.图1 1/4车辆模型Fig.1 one quarter vehicle model一级制动模型A first-order braking model is given by:：dTp/dt=(Tp-Tb)/ て(1) TP是脚踏制动力矩，Tb是实际制动转矩和制动，て是恒定的。