Robust suspension control for in-wheel electric vehicle based on integrating the resistance disturbance observer traction system

This paper presents the integration of chassis control systems for a retrofit in-wheel electric vehicle, including a semi-active magnetorheological (MR) damper and a fuzzy-logic-based traction control system (TCS). The novelty of this design lies in improving ride comfort and preventing wheel slip under various road conditions. The nonlinear hysteresis of the MR damper is considered individually for each vehicle wheel. The Primary objectives are to ensure that the TCS adjusts the torque applied to the wheels based on the Kalman-filter-estimated stator resistance, which is an indirect indicator of the surface friction coefficient. The current-vector distribution across the four in-wheel motors is controlled by the Linear Quadratic Regulator (LQR) controller by adjusting the division between the estimated and reference flux values. This regulation aims to reduce errors in the calculated flux-vector magnitudes. Therefore, the fuzzy traction control system includes an LQR controller that optimally redistributes current across all wheels. The passive suspension system for an internal combustion engine (ICE/P), as the baseline, is compared with the proposed three types of electric vehicle (EV) suspensions, including passive (EV/P), MR passive (EV/MRP), and MR-controlled integrated traction (EV/MRC). The simulation results show that our proposed EV/MRC configuration outperforms most other suspension systems, achieving optimal traction while reducing wheel slip. The results also show that the integrated EV/MRC-controlled system is effective, achieving better performance and lower control effort than both EV/P and EV/MRP in improving the suspension system’s service life and ride comfort for EVs. The peak chassis acceleration is significantly reduced with the proposed EV/MRC combination, reducing from 5.421 m/s 2 for ICE/P to 2.112 m/s 2 . This represents an impressive 38.96% improvement in ride comfort over ICE/P and 58.68% over EV/P.