Simplex based sliding mode control of an underwater gripper

In this paper the sliding mode control theory is applied to a particular un derwater gripper actuated by linear motors which, acting on a hydraulic cir cuit, generate monodirectional forces. In practical realizations actuators often show imprecise relationships between electrical input signals and mec hanical output; such a situation constitutes a source of uncertainties. A s liding mode control methodology based on the use of a simplex of constant c ontrol vectors is presented. The proposed approach is general enough to als o work with different applications. [S0022-0434(00)01204-1].