双电机后驱车辆操纵稳定性分层混杂模型预测控制

为改善车辆在复杂工况下的操纵稳定性，解决低附着路面易失稳的问题，针对后驱双电机轮边驱动电动汽车提出一种结合直接横摆控制与主动转向控制的操纵稳定性控制策略。控制策略采用分层控制结构：上层控制器采用多输入多输出系统的模型预测控制，对目标附加横摆力矩与前轮主动转向角进行求解；下层转矩分配控制器采用混杂模型预测控制（hMPC），将轮胎纵向力的非线性特征简化为分段的混杂系统，在分配驱动转矩时考虑车轮在不同工况下的滑转情况。搭建了基于dSPACE实时仿真系统的仿真平台，在高附着、低附着路面下进行半实物仿真试验。仿真结果表明，与二次规划（QP）转矩分配算法相比，高附着路面工况下平均相对误差减小了17.64%，方均根误差减小了42.86%，最大偏离误差相对减少了7.64%；低附着路面工况下可以有效防止车辆失稳，改善操纵稳定性。

Yaw Stability Control of Distributed Drive Electric Vehicle Based on Hierarchical Hybrid Model Predictive Control

In order to improve the stability of the vehicle under complicated working conditions, especially on low-adhesive road, a driving stability control strategy combining direct yaw control and active steering control is proposed for the dual-motor driven electric vehicle. A hierarchical control structure is used in the control strategy, including an upper controller for calculating the vehicle's additional yaw moment and active steering angle, and a lower controller for distributing the driving torque. The upper controller adopts the model predictive control of the multi-input and multi-output system, and solves the target additional yaw moment and active steering angle; The hybrid model predictive control is adopted in lower controller, which simplified the nonlinear characteristics of the tire into a segmented hybrid system. The slip condition of the wheel is considered while the driving torque is distributed, thereby the steering stability of the vehicle under complicated working conditions is improved. The hardware-in-the-loop simulation platform based on the dSPACE real-time simulation system is used to perform the semi-physical simulation. The simulation results show that compared with the quadratic programming (QP) torque distribution algorithm, the average relative error under high adhesion road conditions is reduced by 13.64%, the root mean square error accuracy is improved by 42.86%, and the relative deviation of the maximum deviation error is reduced by 7.49%; under low adhesion road conditions, the algorithm can effectively prevent vehicle instability and improve steering stability.