Optimal planning of the clutch slipping control for gear shift of 2-speed electric vehicle

The gear shift control of 2-speed AMT (Automated Manual Transmission) of pure electric vehicle is investigated to improve the shift quality. During the inertia phase of the gear shift process, a linear-quadratic optimal controller is designed for minimizing the clutch friction work, vehicle jerk and ensuring the transmission output torque change smoothly. The optimal controller is a time-varying linear feedback form of the states. Based on the simulation results of the optimal controller, the reference trajectory of the clutch speed difference and motor torque are obtained using normalized fitting method. The fitted reference trajectories are used as feed-forward inputs in the inertia phase to accomplish the gear shift process. The control algorithm is confirmed through test on a complete power train simulation model.