A Speed Control for the Reduction of the Shift Shocks in Electric Vehicles with a Two Speed AMT
In the present paper, a speed control algorithm with fast response characteristics is proposed to reduce the shift shock of medium/large sized electric vehicles equipped with a two speed AMT. Shift shocks, which are closely related with to the vehicles' ride comfort, occur due to the difference between the speed of the motor shaft and the load shaft when the gear is engaged. The proposed speed control method for shift shock reduction can quickly synchronize speeds occurring due to differences in the gear ratios during speed shifts in AMT systems by speed command feed forward compensation and a state feedback controller. As a result, efficient shift results without any shift shock can be obtained. The proposed speed control method was applied to a 9 m long medium sized electric bus to demonstrate the validity through a simulated analysis and experiments.