考虑侧向稳定性的分布式电驱动汽车制动滑移率控制
Wheel Slip Control in Distributed Electric Drive Vehicles with Lateral Stability Improvement

针对分布式电驱动汽车在复杂路面紧急制动时引起车轮突然滑转或抱死而导致的车辆失去转向能力甚至甩尾的问题,提出了一种考虑车辆侧向稳定性的电液复合制动滑移率控制策略。滑移率控制采用了滑模极值搜索算法,基于分层结构,即上层为期望制动力矩计算模块,中层为考虑执行器带宽的动态控制分配模块,下层为电液复合执行器,同时还考虑了位置和速率约束且应用主动前轮转向(AFS)系统补偿侧向稳定性。基于MATLAB/Simulink建立了7自由度整车模型,在分离路面典型制动工况下对控制算法进行了验证。结果表明:所提控制策略可以有效减小制动距离,保证车辆侧向稳定性;滑移率控制器可以自适应于路面附着系数的变化。
As imminent braking, distributed electric drive vehicles on complex roads often encounter slipping or locking leading to the loss of steering ability or rear sway. A new wheel slip control strategy with lateral stability improvement for electro？？hydraulic hybrid braking system was proposed. The wheel slip controller was designed by sliding mode extremum？？seeking algorithm with a hierarchical control structure. In the upper layer, the desired braking torque was carried out, and a dynamic control allocator considering different actuators dynamics was employed to determine the optimal split between electric and friction brake torque in the middle layer. In the lower layer, a hybrid actuator system consisting hydraulic brake and the electrical brake was designed based on actuator position and rate constraints. The active front steering (AFS) system was set up to compensate the vehicle lateral stability. The simulation in MATLAB/Simulink environment for split？拨？ straight？？line braking of a 7？？DoFs vehicle model shows that the proposed strategy enables to significantly reduce braking distance with vehicle lateral stability, and the wheel slip controller adapts to variable road adhesion coefficient