Stability Domain Expansion and Instantaneous Center of Rotation Tracking Control Method for 4WIS Vehicles Under High-Speed Turning Conditions

Addressing the challenges of existing wheel angle control methods that fail to fully utilize the side-move and yaw motions of four-wheel independent steering (4WIS) vehicles and struggle to balance stability and trajectory tracking accuracy during high-speed turns, this article proposes a dynamic stability domain expansion and instantaneous center of rotation (ICR) tracking control method for 4WIS vehicles. It includes three modules: ICR control model establishment, stability domain expansion and quantification, and controller design. The ICR control model transforms vehicle states into ICR states, converting traditional wheel angle control into ICR control in polar coordinates. By regulating side-move and yaw motion through ICR, four-wheel angles are allocated. Based on this, the second module uses the limiting ICR states of the 4WIS vehicle to define the global dynamic stability domain, expanding its boundaries to constrain ICR positions, and designing an energy ellipse to quantify vehicle stability to allocating ICR reference. An ICR tracking controller is then designed by integrating the ICR control model. Hardware-in-the-loop experiments confirm that the proposed method ensures precise and stable trajectory tracking for 4WIS vehicles during high-speed turns.