Fuzzy sliding mode control for trajectory tracking on mechatronic arms

Presents the design of a fuzzy sliding mode control algorithm to achieve the specified trajectory tracking on mechatronic arms. The tracking paths are composed of a set of sequentially-operated piecewise sliding surfaces which the system´s state can follow to the equilibrium point in phase plane and from which the total tracking time can be obtained directly. It is shown that each fuzzy controller will refer to a stable closed-loop subsystem in the sense of Lyapunov stability under a common Lyapunov function, and then the overall system is also stable in the sense of Lyapunov stability. Further, the reaching phase of the trajectory which is sensitive to parameter uncertainties or disturbances can be reduced effectively and the system´s state traveling on the paths and finally to the equilibrium point be ensured. The main advantages of the proposed algorithm, in contrast to the conventional sliding-mode control design, are that the tracking time in the reaching phase no longer exists, and the tracking time the first time the system´s state hitting each sliding surface can be evaluated, and that the theoretic total tracking time and the true total one are in good agreement