基于AMESim的电动液压助力转向系统的仿真研究

根据电机转速对转向性能的影响,确定电机转速与方向盘转速和车速的对应关系。利用仿真软件AMESim建立电动液压助力转向系统的仿真模型,包括方向盘输入模型、液压机械模型、轮胎模型和电机控制模型。其中设置方向盘输入为力输入和角输入两种输入端口,采用等效节流阀模拟转阀,轮胎与地面的转向阻力使用齿条两端加载等效滑动摩擦力来模拟,电机控制使用转速环、电流环双闭环PID控制方法。通过三种典型工况的仿真,量化分析控制方法对车辆转向性能的影响,包括转向轻便性、路感、助力响应速度以及稳定性,仿真结果验证了控制方法的有效性,并为控制方法的优化提供了依据。

Simulation Studies of Electro Hydraulic Power Steering Based on AMESim

Properly controlling electro hydraulic power steering system can improve steering performance.The relation of motor speed,vehicle speed and steering speed is gained,according to the influence of motor speed on the steering performance.The simulation model of EHPS is created by AMEsim,which mainly includes the driver input,hydraulic mechanism,tyre and the control of motor.The force and angle input is set in the driver input model.Rotary valve is simulated by four orifices.The steering resistance between tyre and ground is simulated by the coulomb friction on two tips of the rack.The method of double closed-loops PID is used to control the motor.The influence of the control strategy on the steering performance is realized by the simulations of three typical situation,which includes steering portability,road feel,the speed of assist force response and its stability.The results of simulation validate the availability of the control strategy,which is the basic of optimization.