Collaborative Optimization Control of Torque Unloading and Loading for a Dual-Motor Coupling Drive System

Taking a dual-motor planetary two-gear transmission drive system as the research object, this paper analyzes the gear shift process as well as the factors influencing gear shift process and major performance indexes, with emphasis on the effects of torque unloading and loading processes on vehicle impact during gear shift stage. In view of the collaborative operation of main motor, auxiliary motor and gear shift actuator of transmission, this paper proposed a control method and strategy process featuring multiple collaborative gear-shift torque. Then, a simulation platform was built for the vehicle and power system to simulate torque unloading and torque recovery under specified acceleration conditions. Compared with non-collaborative torque controls, the vehicle impact under the multiple collaborative control was reduced by 60% in torque unloading stage and decreased by 80% in torque recovery stage. Furthermore, prototype transmission control units and powertrain systems were developed, and installed on the entire vehicle for validation test. The test results further demonstrated that multiple collaborative gear-shift torque control could effectively reduce the vehicle impact during unloading and loading processes, with gear shift time shortened and gear shift comfort improved.