An optimal tandem active-passive suspension system for road vehicles with minimum power consumption

The authors examine the problem of the synthesis of an optimal control law for active suspensions of road vehicles, based on a model with two degrees of freedom. The possibility of realizing the desired optimal control law with a tandem active-passive suspension is considered. The procedure for determining the desired optimal control law on the basis of suitable design specification is outlined. In the case of a suspension with two degrees of freedom, the possibility of realizing a control law with an active suspension in tandem with a conventional passive one consisting of a spring and a damper is examined. The characteristic parameters of the passive part of the suspension are identified with the aim of minimizing the power required by the active part. The expressions for calculating the values of the elastic constant of the spring and of the characteristic coefficient of the damper, which are both assumed to be linear, are provided. An example of the application is presented