Fuzzy adaptive sliding mode control of a direct drive robot

A number of approaches based on sliding mode control methodology are proposed in the literature for the position control of robotic manipulators. An important problem in this context is chattering, that is high frequency oscillations in the velocity. In this paper, a novel approach is considered which eliminates chattering if the controller parameters are set suitably. Fuzzy adaptation schemes are devised for the on-line adaptation of the parameters of this method. Implementation results show that the fuzzy rule based adaptation schemes ensure a fast system response and a fast convergence of the system states to the sliding surface.