On/off and hybrid control comparison through a state space observer on a nonlinear quarter car dynamic

The car suspension is responsible for the safety and quality in the ride. However, these functions are divergent, safety requires a quick return of the tire, and comfort demands slower accelerations. To perform both, it is common to manufactures to implement an active suspension control based on control strategies. Strategies such as on-off, skyhook and ground hook are wildly implemented on car dynamics. In this paper, a state observer will be implemented on a quarter car nonlinear model to accurate represent the real plant and to feed the on-off and a hybrid control controller. The results show that using the displacement of the chassis as the best solution. In addition, the hybrid controller presented $26.8\%$ improvement than uncontrolled full car.