分布式驱动电动汽车操纵性改善控制策略设计

Control Strategies of Handling Improvement of Distributed Drive Electric Vehicle

摘要:

根据分布式电动汽车各轮驱动/制动转矩独立精确可控的特点，设计了一种改善车辆操纵性能的控制策略.根据不同车速下理想的助力特性曲线设计了差动助力转向控制策略以改善转向轻便性，根据优化的横摆角速度参考模型设计了转矩矢量分配控制策略以改善操纵灵敏性，最后利用纵向力分配算法将两者结合形成差动助力转向/转矩矢量分配联合控制策略.实车试验结果表明，操纵性改善控制策略在保证驾驶员路感信息的前提下明显减小了转向盘转矩，减小了转向盘转角，降低了驾驶员操纵负担.明显提高了整车横摆角速度响应，有效地抑制了车辆的加速不足转向特性，显著地改善了分布式驱动电动汽车的操纵性能.

Abstract:

A control strategy of Handling improvement was proposed for the distributed drive electric vehicle with electric motored wheels which featured the independent and accurate driving/braking of individual wheel. Considering the ideal assistant power character curve under different vehicle velocities, a control strategy of differential drive assist steering was developed, as well as the torque vectoring control strategy according to the optimized reference model of yaw rate. A joint control strategy which was a combination of the differential drive assisted steering strategy and torque vectoring control strategy was presented based on a longitudinal force distribution algorithm. The results of vehicle tests indicate that on the premise to guarantee the road feeling, with the joint control strategy the steering torque and angle are decreased markedly, which means the workload of driver is lowered. The yaw rate response is enhanced obviously, the accelerating understeer is restrained effectively and the handling of the distributed drive electric vehicle is improved significantly.