Force allocation control for distributed drive electric vehicles under split-friction regions and actuator faults.

The stability and drivability of distributed drive electric vehicles over split-friction regions and with actuator faults are studied in this paper by using control allocation. Under the integrated control architecture of high-, medium-, and low-level controllers, a slip-ratio-based synchronization approach is presented to redistribute the driving force for all the driving wheels. The synchronization of slip ratios on wheels is accomplished by autonomously regulating the distribution parameters in the design of a low-level controller. Therefore, the driving force and moment can be adjusted from the design of the regulator on distribution parameters so that the stability and driving performance are ensured when electric vehicles drive over split-friction regions. Subsequently, the concept of distribution parameters is extended to handle actuator faults in electric vehicles by regulating the driving force via the adjustment of distribution parameters. The proportional fault, additive fault, and motor saturation are considered in this paper by compensating for the loss of driving force from the force allocation approach. Numerical examples using CarSim with MATLAB/Simulink and human/hardware-in-the-loop validations are illustrated to demonstrate the efficacy and performance of the proposed control schemes.