In this paper, we present two DCAL-like (Desired Compensation Adaptation Law) controllers for link position tracking of n-link, rigid, revolute robot manipulators. First, we use a simplified stability analysis to illustrate global asymptotic link position-velocity tracking for a DCAL-like controller with nonlinear feedback. The proof is simplified by employing a different structure for the nonlinear feedback than that originally proposed and by making use of the nonlinear damping control design tool. We then use the nonlinear damping tool to show that a DCAL-like controller with linear feedback can guarantee semi-global asymptotic link position-velocity tracking. The proposed nonlinear and linear feedback DCAL-like controllers are experimetally tested and compared using the Integrated Motion Inc. 2-link direct drive robot manipulator.

A link position tracking controller is formulated for an n-link, rigid,revolute, serially-connected robot. The controller generates torque commands tothe individual robot links based on adaptive estimates of the system parametersand measurements of only link positions. A filtering technique, based on thelink position signal, is used to alleviate the need for velocity measurements. Acomplete development of the controller is presented along with a proof ofsemiglobal asymptotic link position-velocity tracking performance. Experimentalvalidation of the proposed controller on the Integrated Motion Inc. (IMI)two-link direct drive robot is also presented. Several extensions to the basiccontroller are described that consider the use of fixed parameterestimates.