分布式驱动电动汽车紧急工况下稳定性控制

Stability control for distributed drive electric vehicle in critical conditions

基于分布式驱动电动汽车具有各轮转矩可单独控制的特点,利用最优转矩分配方法提出其在危险工况下的稳定性控制算法.该算法分为稳定性判断与横摆力矩控制模块、滑移率计算与控制模块及各轮驱动力矩分配模块.稳定性判断与横摆力矩控制模块确定车辆稳定性状态,滑模变结构控制方法用于跟踪理想横摆角速度,输出期望的横摆力矩,确保非线性系统在受到外界干扰时保持稳定;滑移率计算与控制模块计算各轮的滑移状态,通过滑模变结构控制的方法进行各轮滑移率的控制;驱动力矩分配模块综合考虑轮胎力、地面附着等因素,根据横摆控制和滑移率控制的需求,分配各轮驱动力矩.利用联合仿真进行工况验证,结果表明:与各轮力矩平均分配算法相比,所提的力矩分配算法具有更优良的稳定控制效果.

Considering the characteristic that the distributed drive electric vehicle has the ability of independent controllable torque of each wheel,the stability control method based on optimal torque allocation in critical conditions was proposed.This method was divided into stability judgment and yaw moment control module,slip rate calculation and control module,and torque distribution module.Stability judgment and yaw moment control module judged the stability state of the vehicle.Sliding mode variable structure control method was used to track the ideal yaw rate and produce the desired yaw moment,which could make the nonlinear system maintain a steady state under external disturbances.Slip rate calculation and control module calculated the slip state of each wheel,and the sliding mode variable structure control method was adopted to control the slip rate.Torque distribution module allocated the driving torque for each wheel by considering the tire force,ground adhesion and other factors.Typical critical conditions were simulated to verify the effectiveness and feasibility of the proposed stability control method for distributed drive electric vehicle.Results show that the proposed torque distribution algorithm has better stability control effect than the average torque allocation algorithm.