四轮轮毂电机驱动电动汽车电液复合制动平顺性控制策略

液压制动与电机再生制动的时域响应差异导致电动汽车在制动模式切换时产生冲击感，影响驾驶员驾驶感受和乘坐舒适性。以四轮轮毂电机驱动电动汽车为研究对象，提出一种基于分层架构的电液复合制动平顺性控制策略。针对"高压蓄能器+电机泵"式电子液压制动系统（EHB），上层控制器提出基于模糊控制的轮缸压力控制策略；针对制动模式切换过程中产生的冲击，下层控制器提出包括液压介入预测模块和电机制动补偿模块的电液复合制动平顺性控制策略。通过Simulink-AMESim联合仿真平台进行仿真试验验证。结果表明，轮缸压力控制策略能够保证轮缸液压力较好地追随目标压力，且稳态误差不超过2%；电液复合制动平顺性控制策略能够有效提高制动系统的响应速度，同时显著降低制动模式切换时的冲击，能提升车辆制动平顺性和乘坐舒适性。

Electro-hydraulic Brake Control for Improved Ride Comfort in Four-wheel-independently-actuated Electric Vehicles

The time domain response difference between the hydraulic and the electric brake often causes shocks during the brake mode switching process in between for electric vehicles (EVs), which would significantly compromise ride comfort. A ride-comfort-enabled strategy that consists of an upper and a lower controller is proposed for electro-hydraulic-combined brake system in a four-wheel-independently-actuated electric vehicle (FWIA EV). In the upper controller, a wheel cylinder pressure control strategy based on fuzzy control is proposed for an electro-hydraulic brake system (EHB) composed of a high-pressure accumulator and a motor pump. In order to tackle with the impact caused by brake mode switching, a ride-comfort-enabled strategy is proposed in the lower layer. It incorporates a hydraulic intervention prediction module and an electric brake compensation module. Finally, the proposed strategy is examined under various brake scenarios in Simulink-AMESim joint simulation. The results show that the wheel cylinder pressure can precisely track the target pressure with a steady-state error of less than 2% under different brake demands. The brake response is guaranteed and the impact during the brake mode switching process is significantly reduced under the proposed control strategy, thus achieving improved brake performance and ride comfort.