Development of a manipulator suspended by parallel wire structure

A control method of positioning a serial link manipulator suspended by a crane type robot with multiple wires is proposed. The manipulator is fixed on a base plate suspended by three wires. Since the manipulator is suspended by wires, the position and orientation of the base may change according to external forces applied to the manipulator or the change of the manipulator pose. Thus, the inverse kinematics becomes very complicated, and moreover, the mechanism does not seem to be suitable for tasks requiring manipulator tip forces. In this paper, it is shown that the inverse kinematics becomes very simple by using a redundant DOF manipulator, and a method of exploiting the manipulator for tasks requiring forces is described.