An internal force sensor for control of a redundant parallel manipulator

This paper describes an internal force sensor for a new redundant parallel manipulator. In convensional control methods of a redundant parallel manipulator, optimal torque minimized actuator torque or maximized manipulability by using evaluation function is decided and used. However, these methods have to use a torque controlled actuator. It's torque is small, also it is expensive. So, we proposed a new control method using a conventional geared actuator. In our method, internal forces produced by actuator redundancy was detected by an internal force sensor and controlled to be zero. This force sensor is designed to detect only internal forces loaded the end-effector. We demonstrate about the structure and the principle of the proposed internal force sensor, and experimental result of the internal force sensor when internal and outer forces are loaded it.