乘用车双电机冗余电动助力转向系统研究

Research on Dual-Motor Redundant Electric Power Steering System of Passenger Vehicle

为了提高电动助力转向系统的安全性以及可靠性,基于乘用车提出一种双电机冗余电动助力转向技术,采用转向执行双助力电机,可以从硬件上实现冗余,避免任意单电机发生故障时导致转向系统的失效,不仅可以满足转向系统对于轻便型、助力跟随性的要求,还可以减轻单个助力电机的负载提高电机的使用寿命。针对提出的问题,介绍了对双电机阻力转向系统整体结构及工作原理,并对其关键零部件进行分析论述。搭建双电机冗余系统仿真模型,双电机电流分配采用“一主一辅”的控制方式,并进行方向盘多种工况仿真验证。针对助力转向出现抖动问题,结合“扫频试验”,设计输出转矩超前滞后补偿方式进行相位校正补偿。通过实车试验验证了该算法的准确性和有效性。实验结果表明双冗余电动助力转向系统极大提高了转向力矩的稳定性,抑制其扰动性,有较好的助力效果,极大提高系统的可靠性和安全性。

In order to improve the safety and reliability of the electric power steering system,a dual-motor redundant electric power steering technology based on passenger cars is proposed.The dual-motor power steering technology can realize redundancy from the hardware,avoid the failure of the steering system when any single motor fails,not only can meet the requirements of the steering system for lightness and power-assisted followability,but also reduce the load of a single assist motor and increase the service life of the motor.In response to the questions raised,the overall structure and working principle of the dual-motor resistance steering system are introduced,and its key components are analyzed and discussed.The dual-motor redundant system simulation model was built,and the dual-motor current distribution adopted the control mode of"one main and one auxiliary",and the steering wheel was simulated and verified in various working conditions.In view of the jitter problem of the power steering,combined with the"frequency sweep test",the output torque leading and lagging compensation method is designed for phase correction and compensation.The experimental results show that the dual-redundant electric power steering system greatly improves the stability of the steering torque,suppresses its disturbance,has a better assist effect,and greatly improves the reliability and safety of the system.