基于比例继动阀的解耦式制动能量回收

针对纯电动商用车在连续制动时，气源压力偏低会导致驱动轴耦合制动力响应速度变慢，影响制动能量回收效率的问题，提出一种基于比例继动阀的解耦式制动能量回收系统(uncoupled braking energy recovery system, URBS)方案。首先，基于比例继动阀的迟滞特性，采用前馈-单神经元PID控制方法，实现制动气压的准确输出；其次，以电池SOC、车速等为约束条件，根据气源压力信号确定供压模式，并制定解耦式制动能量回收控制策略；最后，基于AMESim，MATLAB/Simulink及TruckSim搭建联合仿真平台，选取单次制动工况与循环工况验证了制动力耦合效果及系统的制动能量回收效果。结果表明，基于比例继动阀的URBS可实现耦合制动力的快速响应，达到稳态压力值75%的时间小于0.1 s，且在中国重型商用车行驶工况和中国重型商用车瞬态工况下有效制动能量回收率分别为10.13%，17.17%。所提URBS方案能有效提高驱动轴耦合制动力的响应速度及耦合精度，可为纯电动商用车气压式URBS方案设计提供参考。

Uncoupled braking energy recovery system based on proportional relay valve

Aiming at the problem that during continuous braking of pure electric commercial vehicles, low air source pressure will lead to slower braking force response speed of drive axle coupling and affect braking energy recovery efficiency, a scheme of uncoupled braking energy recovery system (URBS) based on proportional relay valve was proposed. Firstly, based on the hysteresis characteristics of the proportional relay valve, the feed-forward-single neuron PID control method was adopted to realize the accurate output of braking air pressure. Secondly, taking the battery SOC and vehicle speed as the constraints, the pressure supply mode was determined according to the pressure signal of the air source, and the uncoupled braking energy recovery control strategy was formulated. Finally, a joint simulation platform was built based on AMESim, MATLAB/Simulink and TruckSim, and a single braking condition and cyclic conditions were selected to verify the effect of the braking force coupling and the braking energy recovery of the system. The results show that URBS based on proportional relay valve can achieve rapid response of coupled braking force, with the time of less than 01 second to reach 75% of steady-state pressure value. The effective braking energy recovery rates under CHTC-HT（China heary-duty commercial vehicle test cycle for heavy truck) and C-WTVC(China world transient vehicle cycle) conditions are 1013% and 1717%, respectively. The proposed URBS scheme can effectively improve the response speed and coupling accuracy of coupled braking force of the drive axle, and can provide reference for the design of pneumatic URBS schemes for pure electric commercial vehicles.