An Optimal Linear Active Suspension with Finite Road Preview

A theory of optimal feed-forward control is developed, for a linear system with a disturbance input, based on the analogy between a filtered white noise and a unit step. The theory is applied to an active unicycle suspension on a random road with finite preview and the effect of preview time on the performance index determined. The electro-hydraulic system proposed has a fixed preview distance and requires feedback of the body state variables plus feed forward of the previewed road input through a shift register sequence which is adaptable to a wide range of speeds by automatic switching.