Motor-Clutch Cooperative Control During Gear Shift Process for I-AMT of Electric Vehicle

Abstract:

Pure electric vehicle equipped with two-speed gearbox has a better drivability and economy performance. Due to the simplified structure and no torque interruption during the gear shift process， the configuration that combines friction clutch for high gear and one-way clutch for low gear has become the mainstream scheme of two gear transmission of electric vehicles. However， when the vehicle is driving in reverse gear， the dog clutch should be engaged to overcome the problem that the one-way clutch can only transmit torque in one direction. A novel two-speed automatic transmission （I-AMT） without power interruption based on dog clutch is taken as the research object， and the synergistic control of power motor and reversing actuator motor make the dog clutch act smoothly and quickly. To address the response delay problem of the power motor， the Smith estimator algorithm is used to estimate and compensate the control system. The control strategy is verified by experiments， and the results show that the control strategy can effectively avoid the vehicle jerk when the jaw clutch is engaged， which ensures the smooth gear shift of the transmission in a short time.

Key words:pure electric vehicle;inverse automatic mechanical transmission;dog clutch;cooperative control;Smith predictor