Study on a Two-Link Horizontal Bar Gymnastics Robot with Passive Joint (Motion Control Using Feedforward Control Based on Inverse Dynamics)
Hiroyuki Kojima, Hiroyuki Mitomo*, Yuuki Wada**
and Kenji Sakamoto
Gunma University, 1-5-1, Tenjin-cho, Kiryu, Gunma 376, Japan
* Pioneer, 1-4-1, Meguro, Tokyo 153, Japan
** Victor, 4-8-14, Nihonbashi-honcho, Chuo, Tokyo 103, Japan
This paper describes a motion control method of a twolink horizontal bar gymnastics robot with a passive joint by the use of a feedforward control based on inverse dynamics. A direct current servomotor is placed only at the second joint, and the first link is controlled by the coupling forces and the moments between the active and passive joints. The dynamic behavior of the robot is described by the use of a system with two equations of motion. In the design of the control system, the feedforward control angle of the first joint is first obtained by numerical simulation with the first equation of motion for a desired second joint angle. Then, the feedforward control torque of the servomotor is computed by applying inverse dynamics to the second equation, and the feedforward control voltage is obtained in consideration of the electric circuit of the servomotor. Furthermore, experimental results are given, and the effectiveness of the present motion control method is confirmed.