Adaptive Quasi-Optimal Higher Order Sliding-Mode Control Without Gain Overestimation

This paper presents an adaptive quasi-optimal higher order sliding-mode control (HOSMC) scheme, which is able to avoid gain overestimation. The overall scheme consists of two elements: 1) a quasi-optimal control law that provides fast finite-time stabilization for a chain of integrators; and 2) an adaptive HOSMC with integration of the quasi-optimal control and the integral sliding-mode concept. The adaptation strategy solves the problem of gain tuning without overestimation and has the advantage of chattering reduction. Moreover, the bounds of the uncertainties are no longer needed in the controller design. Simulation results are provided to demonstrate the effectiveness of the proposed HOSMC algorithm.