Active suspension with optimal control based on a full vehicle model

The 7-DOF model of a full vehicle with an active suspension is developed in this paper. The model is written into the state equation style. Actuator forces are treated as inputs in the state equations. Based on the basic optimal control theory, the optimal gains for the control system are figured out. So an optimal controller is developed and implemented using Matlab/Simulink, where the Riccati equation with coupling terms is deduced using the Hamilton equation. The all state feedback is chosen for the controller. The gains for all vehicle variables are traded off so that majority of indexes were up to optimal. The active suspension with optimal control is simulated in frequency domain and time domain separately, and compared with a passive suspension. Throughout all the simulation results, the optimal controller developed in this paper works well in the majority of instances. In all, the comfort and ride performance of the vehicle are improved under the active suspension with optimal control.