Projective Controls for 2-DOF Quarter-Car Suspension

Two control schemes for a two-Degree-Of-Freedom quarter-car suspension are studied here. Both schemes use projective controls to approximate a reference state-feedback control law. The first control scheme assumes a reactive suspension-force input generated by nondynamic control components. Since no actuator dynamics are included, the suspension model is 4^th order. Static projective controls are utilized to yield both passive and active suspension controls, depending on the measurement structure assumed. The second control scheme assumes two reactive force inputs. The first input is generated by (nondynamic) passive components, the second by an actuator which includes its own first-Order dynamics. In this case, the suspension model is 5^th order, since it includes the actuator dynamics. The separation of passive and active components in this control scheme leads to a decentralized control structure. For the example considered, fist-order dynamic projective controllers are introduced in order to stabilize the system.