抄録
Many industrial robot manipulators are driven by d. c. servomotors, where, in addition to gears, springs are used to connect each manipulator arm axis with the corresponding motor axis. In control aspects, the gear in those transmission parts is a positive factor because it suppresses nonlinear dynamics of the manipulator. However, the spring is a negative one ; it makes the joint flexible and causes residual vibration in the end point of the manipulator when the manipulator has to stop abruptly. In this paper we show that the H∞ controller is very effective to eliminate, or minimize to an acceptable level, the residual vibration. The robot manipulator considered in this paper is one with revolute joints (i. e., so-called PUMA type). First we describe the method of designing the H∞ controller, and then we confirm the effectiveness of this controller through experiments by comparison with a PD controller. The experimental results show that the H∞ controller can make the settling time of residual vibration much shorter than the PD controller, although the overshoot is rather large.
