LQR Control for Vehicle Semi-Active Hydro-Pneumatic Suspension Based on Differential Geometry Theory

In order to carry out an effective control for a core component of the semi-active suspension of an engineering vehicle, the nonlinear characteristics of the spring force and damping force of the hydro-pneumatic spring were analyzed and a nonlinear dynamics model for vehicle semi-active hydro-pneumatic suspension was established. The method of exact linearization to the nonlinear system of the semi-active suspension was proposed by applying the differential geometry theory and nonlinear state feedback transformation. Furthermore, the optimal control of nonlinear state feedback was realized by using the LQR. The simulation experiment was implemented with Matlab/Simulink programming. The result shows that, compared with the passive hydro-pneumatic suspension, the semi-active hydro-pneumatic suspension enhances the vehicular ride quality markedly. This research may provide some of references for studying the control of vehicle suspension.