Suppression of chaotic vibrations in suspension system of vehicle dynamics using chattering-free optimal sliding mode control

In this wok, chaos analysis along with chaos control is studied in vertical model of the vehicle system. The chaotic behavior has been demonstrated in the suspension system under the specific initial conditions, values of parameters, and profile of road roughness. In order to analyze chaos in the dynamical model, the power spectrum density and Lyapunov exponent methods are used. Moreover, the phase portrait and Poincare’ sections of the simulations verify numerically chaos in uncontrolled system. For the purpose of chaos control, a novel optimal sliding mode control strategy is designed for stabilization of the system’s behavior via the semi-active suspension using MR fluid damper. As results, the optimal sliding mode control eliminates the chattering phenomenon in the responses and suppresses the chaotic oscillations in comparison with ordinary sliding mode control system. Responses of the feedback system depict the far-better performance of the proposed optimal sliding mode control from the viewpoint of reducing the settling time, overshoot, energy, and amortization in the suspension system.