Predefined-Time Output Feedback Control for Active Vehicle Suspension Systems With Beneficial Couplings, Disturbances, and Nonlinearities

The exploration of energy-efficient active suspension control strategies for high-performance vibration suppression remains a critical challenge, particularly under partial-state measurements, uncertain dynamics, and external disturbances. This article proposes an innovative predefined-time output feedback control scheme for active vehicle suspension systems that achieves superior vibration mitigation with reduced energy consumption. By employing the time-varying scaling function technique, a predetermined-time extended state observer is developed to estimate unmeasurable velocities and lumped disturbance, while a second-order predefined-time filter is designed to avoid the explosion of computational complexity. Furthermore, using the effect characterization method and the X-mechanism reference dynamics, beneficial couplings/disturbances and nonlinearities can be reserved instead of direct cancellation, which leads to significant energy conservation up to 58% compared to other methods. Then, the predefined-time output feedback control is proposed to ensure that settling time can be arbitrarily user-specified using only one parameter, which is independent of initial conditions and control gains. Comparative experiments are performed to present the effectiveness and robustness of the proposed control method.