后轴双电机扭矩矢量控制研究

Torque Vectoring Control Based On Rear Axle Dual Motor

摘要:

车辆的横摆响应受到转向系统、悬架系统、制动系统及驱动系统影响，传统车辆主要以转向输入进行主动控制，随着线控底盘的发展，ESC、后轮转向、扭矩矢量等技术逐步参与到车辆横摆的主动控制中；相对于ESC以制动力差产生横摆力矩，扭矩矢量可在不降低总驱动力的前提下产生横摆力矩，不会引起车辆的制动效应；通过后轴双电机扭矩矢量控制（TVC）产生主动横摆力矩，旨在改善车辆横摆响应，TVC采用前馈与反馈结合控制，基于二自由度车辆模型、目标稳态增益K及横摆角速度-速度修正因子K1建立目标横摆角速度；利用车辆模型逆函数计算横摆力矩前馈值，PID计算横摆力矩反馈值，总横摆力矩转换得到左右车轮纵向力调整量；纵向力调整量与驱动力分量叠加获得左右轮总纵向力；左右轮驱动力过大时可能会受到滑移率、电机扭矩等限制，为保证横摆力矩偏差在要求范围内，需要根据限制情况对左右轮纵向力进行调整；通过仿真验证，TVC可明显改变车辆横摆响应

Abstract:

Abstract:The yaw rate response of vehicles is affected by the steering system, suspension system, braking system, and drive system. Traditional vehicles mainly use steering inputs for active control. With the development of chassis by wire, technologies such as ESC, rear wheel steering, and torque vectoring gradually participate in the active control. Compared to ESC, which generates yaw moment by braking force, torque vector can generate yaw moment without reducing total driving force, without causing braking effects on the vehicle. By generating active yaw moment through rear axle dual motor torque vector control (TVC) to improve vehicle response. TVC adopts a combination of feedforward and feedback control, uses two degree of freedom model , the target steady-state gain K and yaw rate-velocity correction factor K1 to establish the target yaw rate; The vehicle model inverse function is used to calculate the yaw moment feedforward value, and PID is used to calculate the yaw moment feedback value. The total yaw moment is converted to obtain the longitudinal force adjustment amount of the left and right wheels; The adjustment amount and the driving force component are superposed to obtain the total longitudinal force of the left and right wheels; When the driving force of the left or right wheel is too large, it may be subject to restrictions such as slip ratio and motor torque. To ensure that the yaw torque deviation is within the required range, it is necessary to adjust the longitudinal force of the left or right wheel according to the restrictions. Through simulation verification, TVC can improve the vehicle yaw response somewhat.