Establishment of a sliding mode in a nonlinear system by tuning the parameters of a fuzzy controller

In this paper, a novel method for the establishment of a sliding mode in a nonlinear system is presented. The method discussed aims to minimize a cost measure, which is a function of the switching surface. For this purpose, an adaptive fuzzy controller is selected and the parameters of the defuzzifier are adjusted such that the cost is minimized and the system is enforced to behave in sliding mode. The paper considers a 2-DOF direct drive robotic manipulator as the test bed and a standard fuzzy system is used as the controller. The results obtained clearly stipulate that a sliding motion can be achieved by appropriately tuning the parameters of the controller