Model predictive control allocation based on adaptive sliding mode control strategy for enhancing the lateral stability of four-wheel-drive electric vehicles

A novel hierarchical direct yaw moment controller is designed to enhance the lateral stability of the four-wheel-drive electric vehicle. The adaptive sliding mode control (ASMC) technique in the upper-layer controller is employed to compute an additional yaw moment. The lower-layer controller distributes this yaw moment into each independent wheel by utilizing model predictive control allocation (MPCA). The proposed MPCA aims to mitigate the performance deterioration induced by in-wheel motor dynamics and optimize the power consumption stemming from the additional yaw moment. Co-simulation and hardware-in-the-loop (HIL) test is conducted to verify the performance of the proposed controller. Validation results show that the proposed hierarchical ASMC-MPCA controller outperforms the sliding mode control MPCA (SMC-MPCA) and the integrated nonlinear model predictive control (NMPC) with the lowest root-mean-square errors ( RMSE s ) of yaw rate, sideslip angle, lateral deviation, and lowest power consumption. Additionally, the chattering phenomenon in SMC-MPCA can be suppressed effectively by adaptively estimating the parameter uncertainties. The proposed ASMC-MPCA controller also consumes less computational resources than the NMPC and SMC-MPCA, which indicates that the ASMC-MPCA is more suitable for an automotive onboard controller. The comparison between hierarchical and integrated controller frameworks also shows that the hierarchical framework is more suitable for production vehicles under non-powerful vehicle control units.

Automated summary

A novel hierarchical direct yaw moment controller is developed to enhance lateral stability of four-wheel-drive electric vehicles. An upper-layer adaptive sliding mode control (ASMC) technique is employed to compute an additional yaw moment, which is distributed to each wheel using model predictive control allocation (MPCA) in the lower-layer controller. Co-simulation and hardware-in-the-loop (HIL) tests verify the superior performance of the proposed hierarchical ASMC-MPCA controller over sliding mode control MPCA (SMC-MPCA) and integrated nonlinear model predictive control (NMPC). The ASMC-MPCA controller also consumes less computational resources and effectively suppresses chattering phenomenon.