H₂/H_∞ Multi-objective Optimal Control of Vehicle Active Suspensions

In order to coordinate the conflict among performance requirements for active suspension, this paper adopts H₂/H_∞mixed control to constraint optimization, which solve the problem of multi-objective optimization control for the electro-hydraulic active suspension system of half-car. The H₂ norms of the closed-loop transfer function from road disturbance to heave and the pitch accelerations of suspension mass is selected as the index of ride comfort. The H_∞ norms of the closed-loop transfer function from road disturbance to suspension movement, actuator forces and tire dynamic deflection as the handling stability index. Choose the reasonabl value, and finally the optimal control law of the whole state is obtained. Simulation assumptions that a bump in flat road, as the road disturbance pulse input, the control scheme contrast with the passive suspension in the time domain, the results from the simulation demonstrate that comfort and handling stability have been improved, and the contradiction between comfort and handling stability index is solved well.