Derivation of Dynamic Model of Two-Input-Two-Output Torque Difference Amplification Motor Drive System and Independent Left-and-Right Wheel Control with Decoupling Compensator

Abstract

A torque vectoring differential (TVD) enhances the cornering performance by generating a torque difference between the left and right wheels. For electrified vehicles, a TVD with a two-motor-torque difference amplification mechanism (TDA-TVD) is proposed, and it generates a greater torque difference than an Individual-wheel-drive (IWD) system under the same power output from the traction motors. However, owing to the complex gear reduction system including planetary gears and driveshafts, TDA-TVD has problems with the vibration of both the driveshaft torque and the yaw rate while cornering. To deal with these problems, a detailed dynamic model of TDA-TVD is first derived in this study. Secondly, a decoupling compensator is designed to achieve independent drive for the left and right wheels so that any motor drive algorithm designed for IWD systems can be applied. Thirdly, a vibration suppression controller is designed. Then, simulations and experimental evaluations using a real vehicle with the TDA-TVD are performed. The experimental results show the effectiveness of the vibration suppression of driveshafts and yaw rate.