Control strategy for four-wheel independent drive electric vehicles under failure of motor drive systems

Four-wheel independent drive electric vehicle cannot follow the driver's command when one or more motor drive systems fail, which may lead to some serious accidents when the vehicle is running. In order to deal with this problem, a control strategy is proposed in this paper to maintain the stability of 4WID electric vehicle under the failure of motor drive systems. Firstly, failure states of motor drive systems are analysed and classified into Failure-Driving mode and Failure-Stopping mode according to the ability of the vehicle to drive safely. Secondly, a two-layer-control model is designed to maintain the vehicle performance and stability by controlling the remaining normal working motor drive systems for Failure-Driving mode. Thirdly, a control algorithm is designed to help the driver stop the vehicle safely in Failure-Stopping mode. Simulation based on Matlab/Simulink and veDYNA demonstrate that the proposed control strategy can maintain the stability of the 4WID electric vehicle in both Failure-Driving mode and Failure-Stopping mode.