Robust PI and LQR controller design for active suspension system with parametric uncertainty

The robust PI controller and state feedback (Linear Quadratic Regulator) controller are designed to stabilize the dynamic responses of active suspension system with parametric uncertainty followed by road irregularities. To take care about the parametric uncertainties in the suspension system, we design the controller to make robust by polytopic representation of the system. A graphical method is used for computing PI controller parameters for all feasible gain and phase margin specifications. For this purpose, a stability boundary locus in (kp, ki) - plane is used. To achieve the specified gain and phase margin of the system, a gain-phase margin tester is used and stability boundary locus is plotted. The controller gains guarantee the stabilization of the system response with uncertain parameters. The simulation results show the effectiveness of the proposed method.