Servo System Design Considering Low-Stiffness of Robot

This paper describes the practical design method of an advanced servo system for industrial robot manipulators, where it includes a disturbance and velocity observer. At first, it is assumed that the feature on frequency response of the robot is approximated to the feature of two mass mechanism. Actually this fact is confirmed by the some experiments. On the other hand, it is insisted that the actual servo system should be simple for industrial use. And the observer is designed for the load which has the feature of single moment of inertia. On the assumption that there is a difference between these features, it is introduced that the servo system can be effectively used if only the qualified gains are selected considering low-stiffness. And then, the special relation between the frequency analysis and the pole allocations are shown. Finally, the experimental results are introduced.