电动汽车路面转向电机稳定性控制仿真研究

Research on the Stability Control Simulation of Electric Vehicle Steering Motor Based on Road

在不同路面转向行驶时,路面附着系数实时变化对驾驶员路感产生很大的影响,电动汽车路面转向电机稳定性控制能够避免驾驶员因路感缺失而过度反向转动方向盘,造成对车辆的误操作。为了解决路面附着系数变化对转向电机稳定性控制的影响机理,基于路面附着系数变化对EPS系统的助力特性曲线进行了设计。在建立动力学模型的基础上,基于回正力矩的估计算法对路面附着系数进行了推理和辨识,并利用Matlab/Simulink平台对整车动力学模型进行0.3g侧向加速度下阶跃仿真,结合驾驶员理想方向盘转矩拟合得到随路面附着系数和车速变化的助力特性曲线。仿真结果表明,所设计的EPS助力特性曲线在高、低附着系数的路面上都能够满足驾驶员理想方向盘转矩的要求,同时驾驶员在路低附着路面上行驶工况下的路感与正常附着系数的路面感相同,可以有效防止驾驶员的误操作,提高汽车行驶的主动安全性。

An assist characteristic curve of EPS system is designed based on variation of coefficient of road adhe- sion. Firstly, on basis of building kinetic model, inference and identification for the coefficient of road adhesion are carried out based on estimation algorithm of aligning torque, then Matlah/Simulink platform is used to carry out phase step simulation under 0.3g lateral acceleration. The assist characteristic curve of variation of speed and the coefficient of road adhesion integrated with torque fitting of ideal steering wheel of driver are obtained. Simulation results show that the designed EPS assist characteristic curve can satisfy requirement of torque of the ideal steering wheel on road with high or low adhesion coefficient. Road feel of driver under condition of low adhesion road is same as the one of normal adhesion coefficient. It can prevent fault operation of driver effectively and improve active safety of automo- bile.