中英文文献翻译-电动助力转向系统

附录A 外文文献

Electric Power Steering system

1.History

In automobile development course, Steering system experienced four stages of development: from the initial mechanical Steering system (for your DNS setting Steering, abbreviation ) development for Hydraulic Steering system (Hydraulic Power Steering, abbreviation HPS), then again appeared electronically controlled Hydraulic Steering system (Electro Hydraulic Power Steering, abbreviation EHPS) and Electric Power Steering system (Steering, room Power as EPS). Assemble mechanical steering system of car parking and low-speed driving, when the driver's steering control burden too heavy, in order to solve this problem, the American GM in the 1950s took the lead in the car hydraulic steering system. But, hydraulic steering system can't juggle vehicles to speed portability and high speed, so the steering stability Koyo in Japan in 1983, with the company introduced the application of speed sensing function of hydraulic steering system. This new type of steering system can provide speed increased with the decreasing steering, but complicated structure, cost is higher, and cannot overcome hydraulic system itself has many shortcomings, is a cross between a hydraulic steering and electric power steering the transition between the products. In 1988, Japan Suzuki company first in small cars equipped with Cervo Koyo company development on the steering column, power type electric power steering system; In 1990, Japan Honda NSX in sports car company adopted self-developed rack power type electric power steering system, henceforth unveils the electric power steering in cars applications history

2.Working principle

Electric power steering system are as follows: first, the working principle, torque sensor measured on steering wheel drivers on the manipulation of the moment, the wheel speed sensors detect the vehicle driving speed, then present the two signals to ECU; According to the built-in control strategy: ECU, calculates the ideal target booster torque, into current instructions to motor; Then, the power generated by the torque motor slowdown institutions amplification on steering system in mechanical manipulation of the moment, and the driver together to overcome resistance torque, realize to the vehicle steering.

3. Working process

Electric power steering system as traditional hydraulic system alternative products has entered into the auto manufacturing. And had predicted instead, EPS not only applicable to small cars, and some for 12V medium vehicle installed electric system.

EPS system includes the following components:

The torque sensor: detection steering wheel motion and vehicle motion situation;

Electronic control units: according to provide the torque sensor the size of the signal computing power;

Motor: according to the electronic control units; turn power output value generation Reduction gear: improve motor power, and produce turn it sends to steering mechanism.

Other vehicle system control algorithm input information is provided by the car CAN bus (for example steering Angle and bus speed, etc.). Motor drive also need other information, such as motor rotor position and the three-phase motor sensor (current sensor provided). Motor control by four MOSFET, due to micro controller cannot direct drive of large gate capacitance, MOSFET using drive IC form needed the interface, for safety, complete motor control system must implement monitoring, motor control system integration in PCB, usually contains a relay, the relay use, as the main switch under the condition of the fault detection, disconnect motor and electronic control units.

Micro control device must control EPS system and have brushless motor. Micro control device according to the torque sensor provide needed the steering wheel torque information, forming a current control loop. In order to improve the security of the system level, the micro control device should have an on-board oscillator, so even in external oscillator malfunction case, also ensure micro control device performance, also should have chip watchdog. Infineon XC886 integration of the company all the important micro control device component, other safety features for through the software to realize, if must implement safety standards IEC61508 industries, you have to finish all kinds of diagnosis and self-inspection task and increase micro control device work load. At present different customers use of torque sensor and rotor position sensor difference is very big. They use different measuring principle, such as decomposing machine, magnetic resonance device, based on the integration of giant magnet or stance sensor.