Integrated sliding-mode adaptive-robust control

In this paper, an integrated adaptive-robust control approach using sliding-mode method is developed for control of nonlinear uncertain systems. The new approach possesses the advantages of both adaptive control and robust control, and eliminates disadvantages of each. It has the ability to learn, like an adaptive controller, and the ability to handle various uncertainties and reject disturbances like a robust controller. When compared with pure adaptive control the approach used here improves the transient performance, and when compared with pure robust control the conservatism of the design is reduced. Furthermore, global asymptotic stability of the closed loop system is guaranteed. This paper presents the methodology and illustrates the approach using a one-DOF robot arm in the vertical plane under gravity.