Method of operating a dual motor drive and control system for an electric vehicle

摘要

A method for optimizing the torque applied by each motor of a dual motor drive system of an all-electric vehicle is provided, the torque adjustments taking into account wheel slip as well as other vehicular operating conditions.

主权项

1. A method of operating an electric vehicle, the electric vehicle having a first electric motor coupled to a vehicle drive axle and a second electric motor coupled to said vehicle drive axle, the method comprising the steps of:
a) monitoring a wheel speed sensor corresponding to said vehicle drive axle, a first motor speed sensor and a second motor speed sensor, and computing a vehicle speed corresponding to said electric vehicle based on output from said wheel speed sensor, said first motor speed sensor and said second motor speed sensor, wherein said vehicle speed computing step is performed by a traction control command generation unit; b) monitoring a brake sensor and an accelerator sensor, and computing a total torque requirement request based on output from said brake sensor and said accelerator sensor and said vehicle speed, wherein said total torque requirement request computing step is performed by a vehicle torque command generation unit; c) splitting said total torque requirement request into an optimal first motor torque request and an optimal second motor torque request, wherein said total torque requirement request splitting step is performed by an optimal torque splitting unit; d) inputting a wheel target slip ratio and computing a slip error corresponding to said vehicle drive axle based on output from said wheel speed sensor and said vehicle speed and said wheel target slip ratio, wherein said first slip error computing step is performed by said traction control command generation unit; e) minimizing said slip error using a feedback control system implemented by a traction control unit, said traction control unit further performing the steps of transforming said optimal first motor torque request into a first motor torque command and transforming said optimal second motor torque request into a second motor torque command based on said step of minimizing said slip error; f) controlling said first electric motor based on said first motor torque command; g) controlling said second electric motor based on said second motor torque command; and h) repeating steps a)-g) throughout operation of said electric vehicle.