Robust finite frequency H _∞ control of active suspension based on gain scheduling

This paper investigates vibration damping control of a 6-degree-of-freedom (6-DOF) active suspension system for trucks. It establishes a discrete linear parameter-varying (LPV) system model, considering uncertain parameters that vary between laden and unladen conditions. Moreover, the model incorporates real-time measurement of the vehicle body’s sprung mass. To address robust finite frequency problems and time-domain constraints, a novel linear matrix inequality (LMI) condition is devised. This LMI condition effectively handles the nonlinear combination of the gain scheduling control matrix and the time-varying system matrix. By solving a limited number of LMIs, a gain scheduling controller is designed, which is contingent upon the sprung mass. Experimental findings demonstrate the method’s efficacy within the 4–8 Hz vertical vibration frequency range, known for human body sensitivity. Furthermore, the method ensures stringent constraints in suspension control within the time domain.