Study on casting manipulation (experiment of swing control and throwing)

We have been developing a casting manipulator which includes a flexible string in the link mechanism in order to enlarge the work space of the manipulator. Like the casting motion of fly fishing, the necessary motion of the gripper, which is attached at the end of the string, is generated by swinging a rigid link. The gripper is thrown to the target by releasing the string at the suitable time. We deal with the swing motion and throwing motion of the casting manipulation. First, we describe a method of oscillating the casting manipulator by considering it as a two degrees of freedom nonholonomic system. The method of the swing motion generation is investigated through experiments. Next we propose a method of planning of throwing the gripper considering the time delay of releasing the gripper and frictional force which disturbs the flying motion of the gripper. The evaluation by comparing the results of numerical simulation with those of experiments using the casting manipulator hardware has shown the effectiveness of the proposed methods