Temperature Compensation Control Strategy of Creep Mode for Hydraulic Hub-Motor Drive Vehicle

Based on traditional heavy commercial vehicles, a hydraulic hub-motor drive vehicle (HHMDV) is equipped with a set of hydraulic hub-motor auxiliary system (HHMAS) to improve the traction performance and adaptability under complex conditions. In the case of low-speed operation or mechanical transmission failure, the creep mode (CM) can be used to drive the vehicle. Aiming at a common hydraulic system problem that flow loss increases due to temperature variation, a temperature compensation control strategy of the CM is proposed in this paper. By analyzing the speed regulation characteristics of the closed loop of the system in the CM, combined with the efficiency of the hydraulic variable pump (HP) and the hydraulic quantitative motor (HM), and aiming at adjusting the engine work in the optimal curve of the engine, the temperature compensation factor is introduced to control the HP displacement with hydraulic stepless speed regulation. The effectiveness of the proposed temperature compensation control strategy is verified through MATLAB/Simulink and AMESim co-simulation platforms. The simulation results show that the temperature compensation control strategy compensates the system flow loss, improves the low-speed carrying capacity of the system, ensures the economic operation of the engine, and improves the environmental adaptability of the HHMDV, which lays an important foundation for the actual development of the HHMDV. In addition, this paper compensates for the temperature-induced loss from the control point of view and provides a reference for the temperature compensation research of the hydraulic system.