Four-Wheel Independent Drive Vehicle Fault Tolerant Strategy Using Stochastic Model Predictive Control With Model Parameter Uncertainties

With the popularity and increasing demand of new energy automotive, four-wheel independent drive electric vehicles (4WID-EVs) and its distributed control mode is promising to be a better chassis architecture for its flexibility and maneuverability. However, due to the uncertainty of the vehicle internal time-varying parameters and imprecise fault detection method, a novel robust fault estimator-based stochastic model predictive control (SMPC) is proposed in this article to ensure the vehicle lateral motion control and track the desired longitudinal velocity considering the estimation error of motor failure degree. Firstly, a robust H-infinity fault estimator with a linear parameter-varying (LPV) model is established to estimate the real-time fault signal considering the external disturbance and parameter perturbation (i.g. longitudinal and lateral vehicle speed). Then, a SMPC controller framework is developed to alleviate the effect of inevitable evaluated estimation error while the vehicle lateral safety and vehicle speed tracking can be ensured. Finally, the hardware-in-loop (HIL) tests are conducted to prove the feasibility of SMPC controller. The experiment results indicate that the proposed controller framework can effectively preserve vehicle stability and keep vehicle in a healthy state with faster response compared with the traditional fault-tolerant controller.