A Modified Distribution Algorithm For Four-Wheel Independent Drive Electric Vehicles under Actuator Faults

For four-wheel independent drive electric vehicles (4WID-EVs), the increase of actuators with control systems and electrical systems make the vehicle more likely to encounter the failure of the electronic components in actuators. This may further result in actuator faults and influence the stability and handling performance. To handle this problem, an actuator fault model which contains loss-of-effectiveness and additive fault is used to represent the characteristics of actuator faults. Then, based on the fault model, a modified distribution algorithm based active fault tolerant control (FTC) strategy with layered architecture is proposed in this paper. In the upper layer, a 2 degrees of freedom (DOF) vehicle dynamics model based sliding mode controller is proposed to track the reference states, which introduces the compensative steering angle as an extra control variable. In the lower layer, a modified distribution algorithm is used to reconfigure the distribution of the control targets, thus the compensative steering angle can provide the insufficient direct yaw moment. Comparison works are carried out in simulation. The results show that the proposed method improves performance by 72.9% and 87.6% compared with former proposed FTC method under 2 fault conditions. The proposed method might provide a theoretical reference for actual controller design in 4WID-EVs.