Design and control of a seven-degrees-of-freedom manipulator actuated by a coupled tendon-driven system

A seven degrees of freedom manipulator actuated by a tendon drive system has been developed. In order to reduce the weight and volume of the manipulator, each motor was installed on the base frame and the motor torque was transmitted to each joint through a tendon-pulley system. For the tendon drive mechanism, a coupled drive mechanism was introduced, which actuates the manipulator mechanism by controlling the tension of each tendon in the tendon networks designed with coupled tendon structures. Eight direct-drive motors and tendon-pulleys are for a seven degrees of freedom manipulator. The structure of the manipulator developed is first explained then the tendon tension based control method for the coupled drive manipulator is formulated. Finally, through simple experiments using the manipulator in which the control system was installed, the effectiveness of the proposed structure and the control method are demonstrated