Robust Finite-Frequency Vibration Control of In-Wheel Motor Driving Vehicles Based on Torque Coordination and Motor Suspension

Abstract

The in-wheel motor (IWM) drive is an innovative propulsion system with significant potential for transportation electrification. However, the increased unsprung mass due to the IWM unit deteriorates vehicle ride comfort. To address this problem, this article presents a hybrid vibration control strategy that combines torque coordination and motor suspension. Torque coordination enables decoupled control of the vehicle’s longitudinal motion and vertical vibration using the suspension’s anti-dive characteristic. This improves vibration control performance within the body frequency range without affecting longitudinal motion. Motor suspension is integrated with torque coordination to optimize vertical vibration attenuation within the wheel frequency range. A half-vehicle model incorporating both motor suspension and anti-dive geometry is then developed for controller design. Subsequently, a robust finite-frequency $H_{\infty } $ controller is designed to target vertical vibration within the human-sensitive frequency range, while accounting for the uncertainty of the anti-dive geometry. The effectiveness and robustness of the proposed method are verified through simulations and hardware-in-the-loop (HIL) tests. The results demonstrate that the proposed decoupled control can effectively control the longitudinal motion and vertical vibration, while the hybrid control strategy achieves superior performance under varying anti-dive geometry and different driving conditions.