外文翻译：液压起重机卷扬制动的控制

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文献翻译-中文-液压汽车起重机的工作原理

译文：液压汽车起重机的工作原理由飓风丹尼引起的暴雨淹没了北卡罗来纳州夏洛特市的许多地方，小糖溪的河水上涨很快，导致一条火车铁轨栈桥倒塌，一辆内燃机列车坠入河道内。

你可以想象一下，一个412,000磅（186880公斤）的机车是不容易打捞的。

当洪水退去过后，紧急救援队紧急救援队伍带来了三个大型液压汽车起重机——1辆500吨，一辆300吨和一辆175吨，用来把火车从河床里面打捞出来，放置回到轨道上面。

液压汽车起重机利用简单的点对点流体力学概念来举起上千磅重的物品。

液压汽车起重机的设计非常简单，但是他能完成一些看似不可能完成的艰巨任务。

在几分钟内，在公路上这些机器可以举起重达几吨的桥梁；在工厂里，这些机器可以举起重型设备；甚至，在建造海滨房屋的时候帮助打桩。

当有些地方比如海洋世界需要将鲸鱼运送到新的目的地的时候，液压汽车起重机同样可以用来举起装鲸鱼的水箱。

当看到这些液压汽车起重机运行的时候，很难相信它将这些如此重的物品相对轻松的移动，因为这些的物品都是上吨级的。

液压汽车起重机有各种不同的提升力。

只需要通过它的名字就可以轻松的知道许多特定的液压汽车起重机的起重能力，例如：一个40吨吊车能吊起40吨（80000磅或36287 kg ）。

在这里，你将学习起重机如何利用水力学（液压）举起数千英镑的物体，我们会爬进驾驶室向你展示如何操作这些机器。

这全是关于液压的液压起重机是基于一个简单的概念——通过点对点流体力学概念来进行力的传递。

大多数液压机使用的是一些密度很大大到不可压缩的液体。

油（石油）是最常见的被用来做液压机包括液压起重机的不可压缩的液体。

在一个简单的液压系统里面，当一个活塞推动油（石油），油（石油）就将所有的原动力传送到另一个需要带动的活塞。

在一个简单的液压系统里面，当一个活塞被推动，另一个活塞就会被带动。

液压泵产生的压力推动活塞。

在一个液压系统里面的压力由两种液压泵类型中的一种产生：可变排量泵（变量泵）齿轮泵大多数液压汽车起重机使用的是有一对齿合齿轮向液压油加压的双齿轮泵。

制动器外文翻译中英对照

汽车08-1，200801071027，马庆龙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 pedalor 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 (hopef ully) 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 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 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 theinitialposition, 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 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 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. ABSⅡ system 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。

卷扬机液压制动器工作原理

卷扬机液压制动器工作原理说起卷扬机液压制动器工作原理，我有一些心得想分享。

其实一开始接触这个，我都蒙圈了，这么个大机器里面的制动器，到底是咋个工作的呢？我就突然想到咱们骑的自行车。

你看，自行车停下来的时候，咱们捏闸，闸皮就紧紧地抱住车轮，不让它转了，就把车子停住了。

卷扬机的液压制动器呢，有些类似但又复杂得多。

咱们先了解一个重要的专业术语：液压。

简单来讲，液压就是利用液体（液压油）来传递力量。

就好比咱们家里的水管子，打开水龙头，水就会因为水压往前流，如果水管有个小口喷出水的话，你会感觉到强大的冲击力，这就是液压的感觉，在液压制动器里的液压油就像水管里的水。

有意思的是，液压制动器里有一些关键的部件，像制动缸。

这就相当于自行车闸的小把手。

当操作装置要让卷扬机停下来的时候，就会推动液压油进入制动缸。

这时候就得提到一种活塞，你可以把活塞想象成一个大力士，液压油一进来，就像给大力士打气一样，活塞就开始发力了。

这个力就会使得闸瓦抱紧制动轮，就跟用手捏紧闸把，让闸皮抱住自行车轮那样。

打个比方吧，液压油就像一群勤劳的小蚂蚁，活塞就是搬运巨石（制动力）的大怪兽，小蚂蚁们（液压油）齐心合力推动大怪兽（活塞），大怪兽就开始展现它的力量，让闸瓦紧紧咬住制动轮。

说到这里，你可能会问，要是这个力控制不好，那不是很危险？确实呢，这个对于液压的控制是很精密的。

实际应用案例中，在建设工地上的大型卷扬机就特别注重这一点。

如果吊运重物到达指定位置要停止的时候，刹车必须要稳准狠。

这时候就得靠整个液压系统里面专门的压力调节阀等装置，来确保活塞发挥合适的力量。

老实说，我一开始也不明白为啥这个液压系统能有这么精准的控制。

后来学习了相关理论才知道，这里面涉及到很多复杂的计算和精确的机械设计。

比如说，与制动轮的摩擦系数等因素密切相关，不同型号的卷扬机在设计制动器的时候就得把这些都考虑进去。

从实用价值来看呢，了解这些原理有助于我们更好地维护和修理卷扬机。

电动卷扬机的控制——机械专业毕业设计论文外文翻译(中英文翻译、外文文献翻译)

电动卷扬机的控制——机械专业毕业设计论文外文翻译（中英文翻译、外文文献翻译）电动卷扬机的控制——机械专业毕业设计论文外文翻译(中英文翻译、外文文献翻译)英文原文Electrical Winch Controlsby Tom YoungThe form of motor control we all know best is the simple manual station with up and down pushbuttons. While these stations may still be the perfect choice for certain applications，a dizzying array of more sophisticatedcontrols is also available. This article addresses the basic electrical requirements of the motors and user interface issues you will need to address before specifying，building or buying winch controls.To begin with，the manual control stations should be of the hold-to-run type，so that if you take your finger off of the button the winch stops. Additionally，every control station needs an emergency stop (E-stop) that kills all power to the winch，not just the control circuit. Think aboutit―if the winch isn’t stopping when it should，you really need a failsafeway to kill the line power. It’s also a great idea to have a key operated switch on control stations，especially where access to the stations is not controlled.Safe operation by authorized personnel must be considered whendesigning even the simplest manual controls.Controlling Fixed Speed MotorsThe actual controlling device for a fixed speed winch is a three phase reversing starter. The motor is reversed by simply switching the phase sequence from ABC to CBA. This is accomplished by two three-pole contactors，interlocked，so they can’t both be closed at the same time.The NEC requires both overload and short circuit protection. To protect the motor from overheating due to mechanical overloads a thermal overload relay is built into the starter. This has bi-metallic strips that match the heating pattern of the motor and trips contacts when they overheat. Alternatively，a thermistor can be mounted in the motor winding to monitor the motor temperature. Short circuit protection is generally provided by fuses rated for use with motors.A separate line contactor should be provided ahead of the reversing contactor for redundancy. This contactor is controlled by the safety circuits: E-stop and overtravel limits.This brings us to limit switches. When you get to the normal end of travel limit the winch stops and you can only move it in the opposite direction (away from the limit). There also needs to be an overtravel limit in case，due to an electrical or mechanical problem，the winch runs pastthe normal limit. If you hit an overtravel limit the line contactor opens so there is no way to drive off ofthe limits. If this occurs，a competent technician needs to fix the problem that resulted in hitting the overtravel limit. Then，you can override the overtravels using the spring return toggle switchinside the starter―as opposed to using jumpers or hand shooting the contactors.Variable Speed RequirementsOf course，the simple fixed speed starter gets replaced with a variable speed drive. Here’s where things start to get interesting! At the very least you need to add a speed pot to the control station. A joystick is a better operator interface，as it gives you a moreintuitive control ofthe moving piece.Unfortunately，you can’t just order any old variable speed drive from your local supplier and expect it to raise and lower equipment safely and reliably over kids on stage. Most variable speed drives won’t，as theyaren’t designed for lifting. The drive needs to be set up so that torque is developed at the motor before the brake is released，and (when stopping)the brake is set before torque is taken away.For many years DC motors and drives provided a popular solution as they allowed for good torque at all speeds. The large DC motors required for most winches are expensive，costing many times what a comparable ACmotor costs. However，the early AC drives were not very useful，as theyhad a very limited speed range and produced low torque at low speeds. More recently，as the AC drives improved，the low cost and plentiful availability of AC motors resulted in a transition to AC drives.There are two families of variable speed AC drives. Variable frequency inverters are well known and readily available. These drives convert AC to DC，then convert itback to AC with a different frequency. If the drive produces 30 Hz，a normal 60 Hz motor will run at half speed. In theory this isgreat，but in reality there are a couple of problems. First，a typical 60Hz motorgets confused at a line frequency below 2 or 3 Hz，and starts to cog (jerkand sputter)，or just stops. This limits you to a speed range of as low as 20:1―hardly suitable for subt le effects on stage! Second，many lowercost inverters are also incapable of providing full torque at low speeds. Employing such drives can result in jerky moves，or a complete failureto lift the piece―exactly what you don’t want to see when you are tryingto start smoothly lifting a scenic element. Some of the newer inverters are closed loop (obtain feedback from the motor to provide more accurate speed control) and will work quite well.The other family of AC drives is flux vector drives. These units require an encoder mounted on the motor shaft allowing the driv。

大型履带式起重机卷扬液压系统的动态特性分析

大型履带式起重机卷扬液压系统的动态特性分析发布时间：2021-11-04T06:20:55.327Z 来源：《工程建设标准化》2021年8月第15期作者：路程[导读] 卷扬系统是履带式起重机的重要系统，当前普遍采用全液压驱动形式的大型履带式起重机路程浙江省特种设备科学研究院浙江杭州 310020摘要：卷扬系统是履带式起重机的重要系统，当前普遍采用全液压驱动形式的大型履带式起重机，其系统工作性能的优劣直接影响系统整机的可靠性与安全性，因此，需要改善起重机卷扬系统的工作性能。

卷扬系统在重物下放的过程中，由于负载拖动马达转动，所以经常出现失速的问题，需要实现重物的平稳、高效、精确的下放控制时卷扬液压系统的关键。

关键词：大型履带式起重机；卷扬液压系统；动态特性液压系统工作液体循环方式有所不同，可将其分为开式与闭式两种系统，两种系统在重物下放的工况中存在压力冲击、系统动态性能在不同工况下存在差异，无论采用哪种系统，要实现卷扬系统工作稳定、响应快、微动性好的设计目标，需要对液压系统的动态特性进行深入研究，才能全面了解多种工况下系统动态响应特性，对系统的各种参数进行合理的匹配，并优化系统的动态相应。

当前我国对起重机液压系统的参数匹配以及元件选型工作通常采用经验公式及类比的方法，并对液压系统的设计计算多以静态计算为主，对系统动态特性的研究工作正处于起步阶段。

一、履带式起重机概述履带式起重机是一种依靠履带装置行走的移动式起重机械，当前被广泛应用在港口、水电、石油化工等行业。

履带起重机主要由行走机构、动臂、回转机构、底盘与配重等部分组成。

履带式起重机具有起重能力大、接地比压小、转弯半径小、可带载行走以及桁架组合高度可自由切换等优势，因此，被各种起重作业所应用。

按照液压系统的不同，履带式起重机可分为：全开式液压系统起重机、全闭式液压系统起重机以及开闭式混合液压起重机三类。

中小吨位起重机中开式系统安全性好、可拓展节能性好、而且成本低；闭式液压系统不仅电气控制性能好、结构简单、而且易于布置，但其安全性能容易受电控系统可靠性的限制，再加上成本较高，致使该类系统在国外大型企业中大吨位产品应用较为广泛[1]。

盘式制动器制动系统原理外文文献翻译、中英文翻译、外文翻译

盘式制动器制动系统原理外文文献翻译、中英文翻译、外文翻译制动系统原理摩擦力是指抵抗两个物体之间相对运动的力。

在制动系统中，通过产生摩擦力来使汽车停止运动或减速行驶。

摩擦力的大小取决于物体表面粗糙度和接触面所受压力的大小。

当发生摩擦运动时，动能就会转化为热能。

因此在刹车时，必须尽量减少热量的产生，以避免制动系统故障。

摩擦力和制动系统在制动系统中，摩擦力的大小是由控制器控制的。

通过改变摩擦力，可以使汽车停止运动或以不同的速度行驶。

控制器通过制动蹄或制动板传递给旋转的制动鼓或制动盘。

当驾驶员踩在制动脚踏板上的力增大时，摩擦力也会随之增加。

车轮在制动摩擦力的作用下逐渐停止转动，但轮胎和地面之间也会产生摩擦力。

制动器上产生的摩擦力必须与轮胎与地面之间产生的摩擦力大小相匹配，避免车轮锁死或打滑的现象。

为了控制车轮在减速时出现打滑的现象，现在广泛使用电脑控制的制动器。

鼓式制动器的基本操作原理鼓式制动器由一个铸造鼓和连接在制动板上的制动蹄构成。

铸造鼓固定在车轮上，随车轮一起转动。

制动器内还有液压缸、弹簧和连接杆等部件。

制动蹄和摩擦材料连接在一起，制动器工作时，摩擦材料贴附在制动鼓的内表面，制动蹄在力的作用下紧贴在制动鼓的内表面，产生摩擦力。

制动器的工作原理是通过液压缸控制制动蹄的运动，使其紧贴在制动鼓上，从而实现制动效果。

在刹车系统开始工作时，盘式制动器的制动片会被推向制动盘。

制动片与制动盘之间的摩擦力会使得车轮减速或停止旋转。

制动盘通常是由铁制成的，而制动片则通常是由摩擦材料制成的。

制动片与制动盘之间的摩擦力是由制动液压缸内部的液压力驱动的。

这种液压力是由操纵者的脚踏板产生的。

盘式制动器的优点是可以承受更高的温度和更大的力量，因为它们的制动面积更大。

此外，盘式制动器的制动片更容易被更换和维护。

缺点是盘式制动器比鼓式制动器更昂贵，并且更容易受到灰尘和水的影响。

总的来说，盘式制动器是一种高效、可靠的刹车系统，适用于高速行驶和紧急制动。

汽车起重机液压系统中英文对照外文翻译文献

汽车起重机液压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)翻译：汽车式起重机液压系统—技术现状与发展趋势一、行业背景（一）国外工程汽车起重机的发展趋势近20年世界工程起重机行业发生了很大变化。

RT(越野轮胎起重机)和AT(全地面起重机)产品的迅速发展，打破了原有产品与市场格局，在经济发展及市场激烈竞争冲击下，导致世界市场进一步趋向一体化。

为与RT和AT产品抗衡，汽车起重机新技术、新产品也在不断发展。

近年来汽车起重机在英、美等国市场的复兴，使人们对汽车起重机产生新的认识。

几年前某些工业界人士曾预测，RT 和AT产品的兴起将导致汽车起重机的衰退。

日本汽车起重机在世界各地日益流行，以及最近格鲁夫、特雷克斯、林克．贝尔特、德马泰克等公司汽车起重机的产品进展，已向上述观念提出挑战。

随着工程起重机各机种间技术的相互渗透与竞争，汽车起重机会在世界市场中继续占有一席之地。

国外工程起重机从整体情况分析，领先国内10～20年(不同类型产品有所不同)。

随着国外经济发展速度趋于平稳，工程起重机向智能、高性能、灵活、适应性强、多功能方向发展。

25t以下基本上不生产，产品向高附加值、大吨位发展，住友建机、多田野和加藤公司曾于1989年相继推出360t汽车起重机。

住友建机在90年代开发出80t～250t共4种AT产品。

多田野也在90年代相继推出100t～550t共6种特大型AT产品。

加藤公司则研制成NK5000型500t汽车起重机。

行业配套也与国内有所不同：1、下车主要是300kW以上柴油大功率发动机，与之配套的液力变矩器和自动换档变速箱、12吨级驱动转向桥及越野轮胎。

2、上车：高强度材料、大扭矩的起升机构、回转机构、回转支承。

3、液压系统：变量泵、变量马达、电磁换向先导阀及主阀、平衡阀、悬挂系统阀、液压锁、液压缸及管路标准配套件。

4、智能控制系统：力限器显示控制、记忆通讯及单缸顺序伸缩自动控制。

（二）国内工程汽车起重机的发展趋势国内工程机械产品近十年来随着技术的引进、消化、吸收，有了长足的进步，产品性能、可靠性、外观都有较大幅度的提高，但同国外工程机械比较来看，还存在较大差距。

起重机中英文对照外文翻译文献

中英文对照外文翻译(文档含英文原文和中文翻译)Control of Tower Cranes WithDouble-Pendulum Payload DynamicsAbstract：The usefulness of cranes is limited because the payload is supported by an overhead suspension cable that allows oscilation to occur during crane motion. Under certain conditions, the payload dynamics may introduce an additional oscillatory mode that creates a double pendulum. This paper presents an analysis of this effect on tower cranes. This paper also reviews a command generation technique to suppress the oscillatory dynamics with robustness to frequency changes. Experimental results are presented to verify that the proposed method can improve the ability of crane operators to drive a double-pendulum tower crane. The performance improvements occurred during both local and teleoperated control.Key words：Crane , input shaping , tower crane oscillation , vibrationI. INTRODUCTIONThe study of crane dynamics and advanced control methods has received significant attention. Cranes can roughly be divided into three categories based upontheir primary dynamic properties and the coordinate system that most naturally describes the location of the suspension cable connection point. The first category, bridge cranes, operate in Cartesian space, as shown in Fig. 1(a). The trolley moves along a bridge, whose motion is perpendicular to that of the trolley. Bridge cranes that can travel on a mobile base are often called gantry cranes. Bridge cranes are common in factories, warehouses, and shipyards.The second major category of cranes is boom cranes, such as the one sketched in Fig. 1(b). Boom cranes are best described in spherical coordinates, where a boom rotates aboutaxes both perpendicular and parallel to the ground. In Fig. 1(b), ψis the rotation aboutthe vertical, Z-axis, and θis the rotation about the horizontal, Y -axis. The payload is supported from a suspension cable at the end of the boom. Boom cranes are often placed on a mobile base that allows them to change their workspace.The third major category of cranes is tower cranes, like the one sketched in Fig. 1(c). These are most naturally described by cylindrical coordinates. A horizontal jib arm rotates around a vertical tower. The payload is supported by a cable from the trolley, which moves radially along the jib arm. Tower cranes are commonly used in the construction of multistory buildings and have the advantage of having a small footprint-to-workspace ratio. Primary disadvantages of tower and boom cranes, from a control design viewpoint, are the nonlinear dynamics due to the rotational nature of the cranes, in addition to the less intuitive natural coordinate systems.A common characteristic among all cranes is that the pay- load is supported via an overhead suspension cable. While this provides the hoisting functionality of the crane, it also presents several challenges, the primary of which is payload oscillation. Motion of the crane will often lead to large payload oscillations. These payload oscillations have many detrimental effects including degrading payload positioning accuracy, increasing task completion time, and decreasing safety. A large research effort has been directed at reducing oscillations. An overview of these efforts in crane control, concentrating mainly on feedback methods, is provided in [1]. Some researchers have proposed smooth commands to reduce excitation of system flexible modes [2]–[5]. Crane control methods based on command shaping are reviewed in [6].Many researchers have focused on feedback methods, which necessitate the addition necessitate the addition of sensors to the crane and can prove difficult to use in conjunction with human operators. For example, some quayside cranes have been equipped with sophisticated feedback control systems to dampen payload sway. However, the motions induced by the computer control annoyed some of the human operators. As a result, the human operators disabled the feedback controllers. Given that the vast majority of cranes are driven by human operators and will never be equipped with computer-based feedback, feedback methods are not considered in this paper.Input shaping [7], [8] is one control method that dramatically reduces payload oscillation by intelligently shaping the commands generated by human operators [9], [10]. Using rough estimates of system natural frequencies and damping ratios, a series of impulses, called the input shaper, is designed. The convolution of the input shaper and the original command is then used to drive the system. This process is demonstrated with atwo-impulse input shaper and a step command in Fig. 2. Note that the rise time of the command is increased by the duration of the input shaper. This small increase in the rise time is normally on the order of 0.5–1 periods of the dominant vibration mode.Fig. 1. Sketches of (a) bridge crane, (b) boom crane, (c) and tower crane.Fig. 2. Input-shaping process.Input shaping has been successfully implemented on many vibratory systems including bridge [11]–[13], tower [14]–[16], and boom [17], [18] cranes, coordinate measurement machines[19]–[21], robotic arms [8], [22], [23], demining robots [24], and micro-milling machines [25].Most input-shaping techniques are based upon linear system theory. However, some research efforts have examined the extension of input shaping to nonlinear systems [26], [14]. Input shapers that are effective despite system nonlinearities have been developed. These include input shapers for nonlinear actuator dynamics, friction, and dynamic nonlinearities [14], [27]–[31]. One method of dealing with nonlinearities is the use of adaptive or learning input shapers [32]–[34].Despite these efforts, the simplest and most common way to address system nonlinearities is to utilize a robust input shaper [35]. An input shaper that is more robust to changes in system parameters will generally be more robust to system nonlinearities that manifest themselves as changes in the linearized frequencies. In addition to designing robust shapers, input shapers can also be designed to suppress multiple modes of vibration [36]–[38].In Section II, the mobile tower crane used during experimental tests for this paper is presented. In Section III, planar and 3-D models of a tower crane are examined to highlight important dynamic effects. Section IV presents a method to design multimode input shapers with specified levels of robustness. InSection V, these methods are implemented on a tower crane with double-pendulum payload dynamics. Finally, in Section VI, the effect of the robust shapers on human operator performance is presented for both local and teleoperated control.II. MOBILE TOWER CRANEThe mobile tower crane, shown in Fig. 3, has teleoperation capabilities that allow it to be operated in real-time from anywhere in the world via the Internet [15]. The tower portion of the crane, shown in Fig. 3(a), is approximately 2 m tall with a 1 m jib arm. It is actuated by Siemens synchronous, AC servomotors. The jib is capable of 340°rotation about the tower. The trolley moves radially along the jib via a lead screw, and a hoisting motor controls the suspension cable length. Motor encoders are used for PD feedback control of trolley motion in the slewing and radial directions. A Siemens digital camera is mounted to the trolley and records the swing deflection of the hook at a sampling rate of 50 Hz [15].The measurement resolution of the camera depends on the suspension cable length. For the cable lengths used in this research, the resolution is approximately 0.08°. This is equivalent to a 1.4 mm hook displacement at a cable length of 1 m. In this work, the camera is not used for feedback control of the payload oscillation. The experimental results presented in this paper utilize encoder data to describe jib and trolley position and camera data to measure the deflection angles of the hook.Base mobility is provided by DC motors with omnidirectional wheels attached to each support leg, as shown in Fig. 3(b). The base is under PD control using two HiBot SH2-based microcontrollers, with feedback from motor-shaft-mounted encoders. The mobile base was kept stationary during all experiments presented in this paper. Therefore, the mobile tower crane operated as a standard tower crane.Table I summarizes the performance characteristics of the tower crane. It should be noted that most of these limits are enforced via software and are not the physical limitations of the system. These limitations are enforced to more closely match theoperational parameters of full-sized tower cranes.Fig. 3. Mobile, portable tower crane, (a) mobile tower crane, (b) mobile crane base.TABLE I MOBILE TOWER CRANE PERFORMANCE LIMITSFig. 4 Sketch of tower crane with a double-pendulum dynamics.III. TOWER CRANE MODELFig.4 shows a sketch of a tower crane with a double-pendulum payload configuration. The jib rotates by an angle around the vertical axis Z parallelto the tower column. The trolley moves radially along the jib; its position along the jib is described by r . The suspension cable length from the trolley to the hook is represented by an inflexible, massless cable of variable length 1l . The payload is connected to the hook via an inflexible, massless cable of length 2l . Both the hook and the payload are represented as point masses having masses h m and p m , respectively.The angles describing the position of the hook are shown in Fig. 5(a). The angle φrepresents a deflection in the radial direction, along the jib. The angle χ represents a tangential deflection, perpendicular to the jib. In Fig. 5(a), φ is in the plane of the page, and χ lies in a plane out of the page. The angles describing the payload position are shown in Fig. 5(b). Notice that these angles are defined relative to a line from the trolley to the hook. If there is no deflection of the hook, then the angle γ describes radial deflections, along the jib, and the angle α represents deflections perpendicular to the jib, in the tangential direction. The equations of motion for this model were derived using a commercial dynamics package, but they are too complex to show in their entirety here, as they are each over a page in length.To give some insight into the double-pendulum model, the position of the hook and payload within the Newtonian frame XYZ are written as —h q and —p q , respectivelyWhere -I , -J and -K are unit vectors in the X , Y , and Z directions. The Lagrangian may then be written asFig. 5. (a) Angles describing hook motion. (b) Angles describing payload motion.Fig. 6. Experimental and simulated responses of radial motion.(a) Hook responses (φ) for m 48.01=l ，(b) Hook responses for m 28.11=lThe motion of the trolley can be represented in terms of the system inputs. The position of the trolley —tr q in the Newtonian frame is described byThis position, or its derivatives, can be used as the input to any number of models of a spherical double-pendulum. More detailed discussion of the dynamics of spherical double pendulums can be found in [39]–[42].The addition of the second mass and resulting double-pendulum dramatically increases the complexity of the equations of motion beyond the more commonly used single-pendulum tower model [1], [16], [43]–[46]. This fact can been seen in the Lagrangian. In (3), the terms in the square brackets represent those that remain for the single-pendulum model; no —p q terms appear. This significantly reduces the complexity of the equations because —p q is a function of the inputs and all four angles shown in Fig. 5.It should be reiterated that such a complex dynamic model is not used to design the input-shaping controllers presented in later sections. The model was developed as a vehicle to evaluate the proposed control method over a variety of operating conditions and demonstrate its effectiveness. The controller is designed using a much simpler, planar model.A. Experimental V erification of the ModelThe full, nonlinear equations of motion were experimentally verified using several test cases. Fig.6 shows two cases involving only radial motion. The trolley was driven at maximum velocity for a distance of 0.30 m, with 2l =0.45m .The payload mass p m for both cases was 0.15 kg and the hook mass h m was approximately 0.105 kg. The two cases shown in Fig. 6 present extremes of suspension cable lengths 1l . In Fig. 6(a), 1l is 0.48 m , close to the minimum length that can be measured by the overhead camera. At this length, the double-pendulum effect is immediately noticeable. One can see that the experimental and simulated responses closely match. In Fig. 6(b), 1l is 1.28 m, the maximum length possible while keeping the payload from hitting the ground. At this length, the second mode of oscillation has much less effect on the response. The model closely matches the experimental response for this case as well. The responses for a linearized, planar model, which will be developed in Section III-B, are also shown in Fig. 6. The responses from this planar model closely match both the experimental results and the responses of the full, nonlinear model for both suspension cable lengths.Fig. 7. Hook responses to 20°jib rotation:(a) φ (radial) response;(b) χ (tangential) response.Fig. 8. Hook responses to 90°jib rotation:φ(radial) response;(b) χ(tangential) response.(a)If the trolley position is held constant and the jib is rotated, then the rotational and centripetal accelerations cause oscillation in both the radial and tangential directions. This can be seen in the simulation responses from the full nonlinear model in Figs. 7 and 8. In Fig. 7, the trolley is held at a fixed position of r = 0.75 m, while the jib is rotated 20°. This relatively small rotation only slightly excites oscillation in the radial direction, as shown in Fig. 7(a). The vibratory dynamics are dominated by oscillations in the tangential direction, χ, as shown in Fig. 7(b). If, however, a large angular displacement of the jib occurs, then significant oscillation will occur in both the radial and tangential directions, as shown in Fig. 8. In this case, the trolley was fixed at r = 0.75 m and the jib was rotated 90°. Figs. 7 and 8 show that the experimental responses closely match those predicted by the model for these rotational motions. Part of the deviation in Fig. 8(b) can be attributed to the unevenness of the floor on which the crane sits. After the 90°jib rotation the hook and payload oscillate about a slightly different equilibrium point, as measured by the overhead camera.Fig.9.Planardouble-pendulummodel.B.Dynamic AnalysisIf the motion of the tower crane is limited to trolley motion, like the responses shown in Fig. 6, then the model may be simplified to that shown in Fig. 9. This model simplifies the analysis of the system dynamics and provides simple estimates of the two natural frequencies of the double pendulum. These estimates will be used to develop input shapers for the double-pendulum tower crane.The crane is moved by applying a force )(t u to the trolley. A cable of length 1l hangs below the trolley and supports a hook, of mass h m , to which the payload is attached using rigging cables. The rigging and payload are modeled as a second cable, of length 2l and point mass p m . Assuming that the cable and rigging lengths do not change during the motion, the linearized equations of motion, assuming zero initial conditions, arewhere φ and γ describe the angles of the two pendulums, R is the ratio of the payload mass to the hook mass, and g is the acceleration due to gravity.The linearized frequencies of the double-pendulum dynamics modeled in (5) are [47]Where Note that the frequencies depend on the two cable lengths and the mass ratio.Fig. 10. Variation of first and second mode frequencies when m l l 8.121=+.Fig. 10 shows the two oscillation frequencies as a function of both the rigging length and the mass ratio when the total length from trolley to payload is held constant at 1.8 m. The total length is set to this value because it corresponds to the maximum length of the tower crane that was shown in Fig. 3. This maximum length corresponds to the largest possible swing amplitudes, so Fig. 10 represents the frequencies that are possible in this worst-case scenario. The low frequency is maximized when the two cable lengths are equal. Note that over the wide range of parameter values shown in Fig. 10, the low frequency varies only ±10% from its median value of 0.42 Hz. In contrast, the second mode deviates ±34% over the same parameter range.Ⅳ. CONCLUSIONA dynamic analysis of a tower crane with a payload exhibiting double-pendulumdynamics was presented. A simplified model was used to estimate the frequency andcontribution to the total response of each of the vibratory modes. An input-shaping control method to limit the residual oscillation, with robustness to errors in frequency, was then developed using the simple model.This input shaper was experimentally tested for various cases, and its robustnessto changes in suspension cable length and nonlinear effects during slewing werepresented. The influence of this input shaper on operator performance was then examined for two different obstacle courses, one simple and one difficult. The human operators negotiated the two obstacle courses both locally and remotely, teleoperating the crane via the Internet. Input shaping was shown to dramatically improve task completion times, while reducing the number of obstacle collisions. An ANOV A analysis showed that this improvement was statistically significant for nearly all tests.运用双摆载荷动力学控制塔式起重机摘要：起重机的作用之所以有限，是因为载荷由架空缆支撑着，而架空缆在起重机运行期间是允许振动的发生。

电动卷扬机的控制外文文献翻译

翻译部分英文原文Electrical Winch Controlsby Tom Young The form of motor control we all know best is the simple manual station withup and down pushbuttons. While these stations may still be the perfect choice for certain applications，a dizzying array of more sophisticated controls is also available. This article addresses the basic electrical requirements of the motors and user interface issues you will need to address before specifying，building or buying winch controls.To begin with，the manual control stations should be of the hold-to-run type，so that if you take your finger off of the button the winch stops. Additionally，every control station needs an emergency stop (E-stop) that kills all power to the winch，not just the control circuit. Think about it—i f the winch isn’t stopping when it should，you really need a failsafe way to kill the line power. It’s also a great idea to have a key operated switch on control stations，especially where access to the stations is not controlled.Safe operation by authorized personnel must be considered when designing even the simplest manual controls.Controlling Fixed Speed MotorsThe actual controlling device for a fixed speed winch is a three phase reversing starter. The motor is reversed by simply switching the phase sequence from ABC to CBA. This is accomplished by two three-pole contactors，interlocked，so they can’t both be closed at the same time. The NEC requires both overload and short circuit protection. To protect the motor from overheating due to mechanical overloads athermal overload relay is built into the starter. This has bi-metallic strips that match the heating pattern of the motor and trips contacts when they overheat. Alternatively，a thermistor can be mounted in the motor winding to monitor the motor temperature. Short circuit protection is generally provided by fuses rated for use with motors.A separate line contactor should be provided ahead of the reversing contactor for redundancy. This contactor is controlled by the safety circuits: E-stop and overtravel limits.This brings us to limit switches. When you get to the normal end of travel limit the winch stops and you can only move it in the opposite direction (away from the limit). There also needs to be an overtravel limit in case，due to an electrical or mechanical problem，the winch runs past the normal limit. If you hit an overtravel limit the line contactor opens so there is no way to drive off ofthe limits. If this occurs，a competent technician needs to fix the problem that resulted in hitting the overtravel limit. Then，you can override the overtravels using the spring return toggle switch inside the starter—as opposed to using jumpers or hand shooting the contactors.Variable Speed RequirementsOf course，the simple fixed speed starter gets replaced with a variable speed drive. Here’s where things start to get interesting! At the very least you need to add a speed pot to the control station. A joystick is a better operator interface，as it gives you a more intuitive control of the moving piece.Unfortunately，you can’t just order any old variable speed drive from your local supplier and expect it to raise and lower equipment safely and reliably over kids on stage. Most variable speed drives won’t，as they aren’t designed for lifting. The drive needs to be set up so that torque is developed at the motor before the brake is released，and (when stopping) the brake is set before torque is taken away.For many years DC motors and drives provided a popular solution as they allowed for good torque at all speeds. The large DC motors required for most winches are expensive，costing many times what a comparable AC motor costs. However，the early AC drives were not very useful，as they had a very limited speed range and produced low torque at low speeds. More recently，as the AC drives improved，the low cost and plentiful availability of AC motors resulted in a transition to AC drives.There are two families of variable speed AC drives. Variable frequency inverters are well known and readily available. These drives convert AC to DC，then convert it back to AC with a different frequency. If the drive produces 30 Hz，a normal 60 Hz motor will run at half speed. In theory this is great，but in reality there are a coupleof problems. First，a typical 60 Hz motor gets confused at a line frequency below 2 or 3 Hz，and starts to cog (jerk and sputter)，or just stops. This limits you to a speed range of as low as 20:1—hardly suitable for subtle effects on stage! Second，many lower cost inverters are also incapable of providing full torque at low speeds. Employing such drives can result in jerky moves，or a complete failure to lift the piece—exactly what you don’t want to see when you are trying to start smoothly lifting a scenic element. Some of the newer inverters are closed loop (obtain feedback from the motor to provide more accurate speed control) and will work quite well.The other family of AC drives is flux vector drives. These units require an encoder mounted on the motor shaft allowing the drive to precisely monitor the rotation of the armature. A processor determines the exact vector of magnetic flux (thus flux vector drive) required to rotate the armature the next few degrees at a given speed. These drives allow an infinite speed range，as you can actually produce full torque at zero speed. The precise speed and position control offered by these drives make them a favorite in high performance applications.PLC-based controls provide system status as well as control options. This screen give the operator f ull access to Carnegie Hall’s nine stage floor lifts.PLC Based SystemsA PLC is a programmable logic controller. First developed to replace the relay based industrial control systems of the ’50s and ’60s，these controls are at home in rugged，industrial environments. These are modular systems with a great variety of I/O modules allowing semi-custom hardware configurations to be assembled easily at a reasonable price. These include position control modules，counters，A/D and D/A converters and all sorts of solid state or hard contact closure outputs. The great variety of I/O components and the modular nature of the PLC make this an effective way to build custom and semi-custom control systems.The greatest drawback to PLC systems is the lack of really great displays to tell you what they are doing or to help you program them. Monochrome and mediumresolution color displays are the norm，as the primary use for these components in on a factory floor.One of the first major PLC systems used in a large entertainment venue is the complex lift and wagon system at the original MGM Grand (now Bally’s) in Las Vegas. Several manufacturers offer standard PLC-based systems and a host of semi-custom acoustic banner，shell，and lift control systems is also available. The ability to build custom systems from standard building blocks is the greatest strength of PLC-based controls.High End ControllersThe most sophisticated rigging controllers go well beyond speed，time，and position control. They include the ability to write complex cues，record profiled moves，and manage multiple cues running at once.Many of the larger opera houses are moving toward point hoist systems，where there is a separate winch for each lift line (the rigging equivalent of dimmer per cir cuit). When multiple winches are used to carry a single piece，the winches must be perfectly synchronized，or the load can shift so that an individual winch can become dangerously overloaded. The control system must be able to keep selected winches in synch or provide a rapid，coordinated stop if a winch is unable to stay in synch with the others. With a typical top speed of 240 fpm and a requirement to keep the winches within a 1/8″ of each other，you have less than three milliseconds to recognize a problem，attempt to correct the errant winch’s speed，determine that you’ve failed and initiate a coordinated stop of all the winches in the group. This takes a lot of computing，fast I/O，and well-written software.There are two very different approaches to large rigging control systems. Originally，a single console was used，with the usual problem of where it should be located for the operator’s optimum view. Unfortunately this can change not only from show to show，but also from one cue to the next. This dilemma has been partially addressed by using video cameras at different locations in conjunction with 3D screen graphics that allow the operator to view the expected rigging motion three dimensionally from any viewpoint. This allows the operator to view the on screen movement of the rigging from a viewpoint that matches his actual view of the stage，or the actual view of a closed circuit camera. For complex moves withinter-related pieces this makes the control and understanding of what is happening much simpler.The other approach is a distributed system，with several portable consoles. This allows different operators to control different aspects of the rigging，in the same manner we have done with manual sets. A dramatic example of this approach is used by the Royal Opera at Covent Garden，where there are ten consolescontrolling a total of 240 motors. Each console has five playbacks，and is set up so that each motor is assigned to a single console. One operator and console could control everything，but frequently one console may be running stage lifts，another the onstage rigging，and a third is being used backstage to move stored drops.Cutting-edge portable consoles allow multiple operators to control the action from the best vantage points and provide 3D displays.Reprinted from PROTOCOL，the Journal of the Entertainment Services and Technology Association () Fall 2003 issue. ©2003 ESTA.ConclusionThe tremendous variety of rigging control systems currently available ranges from the pushbutton station to complex multi-user computerized control system. When shopping for rigging control systems you generally get what you pay for. The most important features are safety and reliability. These are features with real value，and you should expect to pay a fair price for this security. Work with an established manufacturer who can show you working installations and who will put you in contact with users who have requirements similar to yours.中文译文电动卷扬机的控制对于电动机的控制，我们所知道的最好的方式就是使用由许多点动式按钮组成的简单的手工操作台。