A composite adaptive output feedback tracking controller for robotic manipulators

This paper provides a solution to the composite adaptive output feedback tr acking control problem for robotic manipulators. The proposed controller ut ilizes an update law that is a composite of a gradient update law driven by the link position tracking error and a least squares update law driven by the prediction error. In order to remove the controller's dependence on lin k velocity measurements, a linear filter and a new prediction error formula tion are designed. The controller provides semi-global asymptotic link posi tion tracking performance. Experimental results illustrate that the propose d controller provides improved link position tracking error transient perfo rmance and faster parameter estimate convergence in comparsion to the same controller using a gradient update law.