Reference model based adaptive control of a hybrid suspension system

The paper presents a new adaptive controller structure for a hybrid quarter-vehicle suspension system containing a low bandwidth actuator and a semi-active damper. The optimal control force to ease the conflict between ride comfort, ride safety and limited suspension deflection is obtained from a reference model based on a passive suspension system with timevarying stiffness and damping. By allocating the resulting control force to the two actuators, the power demand of the hybrid suspension system is significantly lower compared to a high bandwidth active system although their performance is similar. Stability of the adaptive controller structure is guaranteed using a Lyapunov function approach. The hybrid suspension is compared with benchmark systems in simulations under realistic assumptions regarding nonlinearities of the suspension elements, the actuator and sensor architecture as well as the road profile.