汽车电动助力转向系统控制现状分析

Analysis of current control status of the electric power steering system

针对改善电动助力转向系统的轻便性、回正性及鲁棒性和整车稳定性的问题,在分析EPS基本工作过程和建立动力学模型的基础上,对其关键控制内容的现状进行了深入研究和比较,提出了各控制内容研究的热点和难点,指出了EPS控制趋势是充分利用系统的工作特性,通过智能控制及优化算法兼顾了转向系统和整车性能的提高。利用动力学模型、助力特性曲线查表和电机PID控制建立了simulink仿真模型,研究结果表明,动力学参数值会影响系统的稳定性、PID控制参数会影响助力电流的跟随性、助力特征会改变不同阻力矩和车速下的转向轻便性和路感。该建模仿真过程可作为开发相关控制策略的参考。

Aiming at improving the steering agility,returnability,robustness of the electric power steering and the stability of vehicle,based on working principle and dynamic model of the EPS,the key control technologies were researched and compared,the research hotspot and difficulty were pointed out. The control trend of EPS that the vehicle performance and steering performance were same considered by using EPS working character,intelligent control and optimization algorithm was proposed. The comprehensive simulink model was built by combining dynamic model,assist curve table with the motor PID control. The results indicate that the dynamic parameter affects system stability,the different PID control parameter influences the following behavior of DC current,assist characteristic valve reflects different steering agility and road feel for different steering resisting torque and speed. The simulation process can be referenced when developing the control strategy.