FORCE CONTROL IN ELECTROHYDRAULIC ACTIVE SUSPENSIONS

For a simple vehicle active suspension system complete optimality and zero steady state body displacements may be achieved if the axle and b ody accelerations, and other easily measured quantities, are included in the performance index. Apart from not requiring an observer, this a lso allows the optimal feedback gains to be determined for an arbitrar y body spring rate. In a theoretical example, model parameters matchin g those of an experimental test rig are employed. The results of compu ter simulations, with and without an electrohydraulic servovalve and a ctuator, are compared to demonstrate the effects of inner loop gain on force control. Aspects of the system behaviour including lockup are c ommented upon.