A near output feedback controller for a general class of robot manipulatorsystems

In this paper, we propose a robust near output feedback (which refers to th e fact that the control scheme uses dynamic feedback of the output but requ ires knowledge of the initial conditions of other states) link position tra cking controller for a class of robotic systems, which includes the rigid-l ink flexible-joint (RLFJ) robot manipulator and the rigid-link electrically -driven (RLED) robot. The method uses a bank of dynamic filters, with the l ink position tracking error as the input, to generate surrogates for the un measurable system states. One of these generated filter states is then used in the feedback control strategy. The method is distinguished from the pre vious results by the limited amount of modelling information required, the utilization of only link position measurements and knowledge of the initial conditions and the overall simplicity of the controller. Even though the a pproach only requires link position measurements and knowledge of initial c onditions, the controller exhibits good robustness properties while ensurin g semiglobal uniformly ultimately bounded link position tracking.