中文摘要：

为提高轮毂电机驱动电动汽车转向过程的操纵稳定性和转向轻便性,提出电子差速与差动助力转向的协调控制方法,通过分配左右轮毂电机的转矩,实现对汽车转向稳定性和转向盘转向助力协调优化控制。分别对电子差速与差动助力转向控制方式进行分析,得出两种控制趋势以及与车辆状态变化响应的一致性,验证了协调控制的可行性;采用设置权重系数的方法设计了协调控制策略。分析车速及转向盘转角对车辆横摆角速度以及驾驶员转向盘转矩的影响,设计出车速自适应的协调控制权重系数。进行Matlab与CarSim的联合仿真以及实车道路试验验证,仿真与道路试验结果均表明协调控制策略兼顾了车辆差速转向稳定性与驾驶员转向盘转向助力的性能,实现了低速时差动助力转向控制为主以降低驾驶员转向手力,高速时电子差速为主以提高车辆稳定性的综合控制目标。

英文摘要：

Coordinated control of electronic differential and differential assist steering is proposed to improve vehicle handing stability and steering portability when electric vehicle driven by in-wheel motors steering. Coordinated optimal control of the vehicle stability and assist steering of steering wheel is realized by re-distributing torques of left and right in-wheel motors. Two kinds of control methods are analyzed to conclude consistency of control trend and state respond, which can validate the feasibility of coordinated control. Meanwhile,the coordinated control strategy is designed by setting a weight function. The effect of speed and steering wheel angle on vehicle yaw rate and steering wheel torque is analyzed, and the weight function according to the vehicle speed would be designed. Matlab co-simulation with Car Sim and road testing have carried out and demonstrated that the coordinated control strategy can give consideration to the vehicle stability of differential steering and assist steering for drivers. Reducing steering torque based on differential steering control in low speed and improving the stability on electronic differential in high speed is realized comprehensively.