Predictive time-delay control of vehicle suspensions

A predictive control methodology is introduced for active vehicle suspensio n control, taking into account the effect of time delay as an inherent char acteristic of active systems in the absence of preview information. In this method, at each time instant, the control signal is calculated by minimizi ng a performance index, based on the predicted response in a finite predict ion horizon. The discrete predictive methodology, compared with the widely used linear quadratic regulator method, is easier to formulate and results in a discrete-time control algorithm suitable for digital control, and time delays can be more easily introduced in the formulation. In this paper, pr edictive control simulation results are compared with passive control resul ts. It is shown that this method is capable of improving ride performance o f the single-degree-of-freedom quarter-car model for a wide range of input frequencies in the presence of time delay, while in the meantime it maintai ns the maximum suspension travel below the maximum of passively controlled suspensions.