Posture control of casting manipulation

Abstract

We develop a casting manipulator which includes a flexible string in the link mechanism to enlarge the work space of the manipulator. During casting manipulation the gripper is thrown to the target by releasing the string at a suitable time after generating enough motion by swinging. In this paper we deal with the posture control of the gripper after the throwing motion. First, we point out the problems of planning for throwing the gripper while considering its posture when catching. Then we propose a method of applying an impulsive force to the gripper in the air through the string by restricting the motion of the string. Investigating the characteristics of the string through experiments, we confirm the effectiveness of the impulsive force. This method was evaluated by comparing the results of numerical simulations with those of our experiments using the experimental casting manipulator hardware.