基于主动后轮转向的车辆稳定性控制策略

Vehicle Stability Control Strategy Based on Active Rear Wheel Steering

为实现四轮轮毂电机驱动车辆的操纵稳定性控制,提出了主动后轮转向和附加横摆力矩复合控制策略。针对高速行驶转向灵敏度大的问题,对前后轮转向比进行优化。策略采用分层式控制框架,上层基于线性时变模型预测控制算法,建立了四轮轮毂驱动车辆时变预测模型,推导和跟踪包含后轮转向系统的理想输出轨迹,并计算了跟踪理想状态轨迹所需附加力和力矩。下层通过求解四轮转矩分配优化问题,实现了滑移率阈值控制,解决了再生制动和机械制动的分配问题。仿真结果表明,提出的复合控制策略能够达到预期控制效果,改良了车辆横纵向稳定性。

A compound control strategy of active rear-wheel steering and additional yaw moment was proposed to realize the handling and stability control of electric vehicle with four in-wheel motors.Aiming at the problem of high steering sensitivity during high-speed driving,the steering ratio of front and rear wheels was optimized.A hierarchical control framework was used.Based on the linear time-varying model predictive control algorithm,the time-varying predictive model of four in-wheel motors drive vehicle was established in the upper layer.The ideal output trajectory including the rear wheel steering system was deduced and tracked.The additional force and torque needed to track the ideal state trajectory were calculated.The threshold control of the slip ratio was realized by solving the four-wheel torque distribution optimization problem,and the distribution problem of regenerative braking and mechanical braking was solved in the lower layer.The simulation results show that the proposed compound control strategy can achieve the desired control effect,and the vehicle lateral and longitudinal stability is improved.