Barrier Function-Based Adaptive Sliding Mode Control for Application to Vehicle Suspensions

A barrier function-based adaptive sliding mode control (SMC) strategy is proposed for the vehicle active suspension system in this article. The barrier function-based adaptive law is applied to design the sliding mode controller, which can ensure the finite-time convergence of the suspension system. Meanwhile, the proposed adaptive law can achieve greatly chattering reduction without requiring the prior information of the upper bound of system uncertainties. Furthermore, the time-delay estimation technique is applied to design the simple and efficient model-free controller. Therefore, the proposed controller has the strong robustness against the nonlinearities and uncertainties of the active suspension system, and it is very practical in actual scenarios. In addition, considering the transient and steady-state performance of the active suspension system, a prescribed performance function is adopted to constrain the vehicle displacement with its convergence rate, maximum overshoot, and steady-state value. Finally, compared with the conventional SMC and PD control, comparative experiments of a quarter-car active suspension platform are performed to verify the effectiveness of the proposed strategy.