[JRSJ Vol.21, No.4, pp.61-66]
In assembly system, one of the primary factors of the bandwidth limitation is the flexibility of the base on which a tool or manipulator is mounted. We have shown that there exists a set of configurations in which high robustness and controllability are obtained even with high-gain error feedback of the end effector. Based on the positive realness of the transfer matrix, we have defined `Robust arm configuration' which is a special configuration where the system is passive. We have also proposed a measure which indicates the distance from robust arm configuration. In this paper, we propose a mode shape compensator which improves the robustness of the arm configuration where the robustness is not high enough. The compensator consists of a constant gain matrix and acceleration feed back of each joint. The structure is simple and easy to use. We also show the method of designing the mode shaping matrix. The validity is confirmed by a numerical example. A high bandwidth positioning is realized with obtained compensator.
Key Words: Flexible Base・ Industrial Robots・ Controllability・ Positive Realness・ Robust Control
[JRSJ Vol.21, No.4, pp.61-66]