Experimental study of variable idle speed control for an in-wheel electric vehicle drive

摘要

A new type clutch device is integrated into the drive train of a wheel drive electric vehicle to realize a flexible connection between the hub and the motor. Unlike the internal combustion engine (ICE) which has a minimal rotational speed, electric motor is capable of idling at variable speeds. Then, a start-up mode for such a novel in-wheel drive system is proposed, which separates the motor starting and the load operation. Firstly, a simplified model of the drive train system is studied, and the performance indices for evaluating vehicle start-up are introduced. Afterwards the proposed starting method is investigated, and the idle speed is optimally tuned for finding a balance between the discontinuity of the wheel acceleration and the desired motor torque at the moment of clutch closure. Finally, the experiments are conducted on a laboratory test bench, and the results validate the improved comfort level and the enhanced torque capacity by applying the variable idle speed control, compared with the obtained results by using the fixed idle speed control.