Active Disturbance Rejection Control for Active Suspension System of Nonlinear Full Car

In this paper, a full car model with seven degrees of freedom is established for the research of active suspension system, and a virtual prototype is built in Adams to compare and validate it, in particular. Then active disturbance rejection control (ADRC) is applied for the control system. The suspension system is complex for its nonlinearities from the springs, dampers, and irregular excitations from road surface. This paper considers the nonlinear characteristics and complex behavior of real vehicles, and uses extended state observer (ESO) to estimate and eliminate them from the controlled system. After decoupling the full car system, three ADRC controllers are designed to balance the vertical vibration, rolling and pitching movement, respectively, thus producing four active control forces of each suspension by matrix transformation. The simulation results are compared with fuzzy PID controlled system, which show that ADRC has good performance over nonlinearities, perturbations and bounded uncertainties.