Robust observer-based controller and its application in robot control

In this paper, we present a robust observer-based controller (ROC) for robot manipulators to achieve robust velocity estimation and better operational space tracking performance. Without link velocity measurements, the overall ROC system can achieve a semi-global asymptotical stability result for the position and velocity tracking errors, and position and velocity estimation errors. Experimental results using PUMA 560 indicate that the proposed ROC is able to obtain more accurate and less ripple velocity estimation than that obtained from an observer-controller, hence higher tracking performance can be achieved.