On-line Parameter Estimation and Adaptive Gain Smooth Sliding Observer-Controller for Robotic Manipulator Control

On-line, closed loop estimation scheme, for time-varying parameters is proposed in order to obtain useful information despite loads, external disturbances and faults detection. An adaptive gain, smooth sliding observer- controller is developed to control uncertain parameters, n -degree of freedom (n -DOF), rigid links-rigid joints robotic manipulators. In order to alleviate chattering, smooth switching function, instead of pure relay one, is used into the observer and the controller. The gain of the switching functions is adaptively updated, depending on the estimation error and tracking error, respectively. Using adaptive gains, the response is smoother and tracking performances are improved. Simulation results with a two degree of freedom (2-DOF) robotic manipulator are presented to show the interest of the approach.