Robust pole location for an active suspension quarter-car model through parameter dependent control

This paper addresses the problem of robust control design for an active suspension quarter-car model by means of a parameter dependent state feedback gain. Sufficient conditions are given for the existence of a robust stabilizing parameter dependent control law which assures to the uncertain closed-loop system a prespecified pole location inside a circle on the left-hand half of the complex plane. The sprung mass is considered as an uncertain parameter belonging to a known interval (polytope type uncertainty). The robust stabilizability condition is formulated in terms of a set of linear matrix inequalities involving only the vertices of the uncertainty polytope. The technique proposed allows to impose to the closed-loop system pole locations that cannot be obtained with constant feedback gains. A comparison with recent results using the classical LQR approach illustrates the method proposed.