Abstract: Based on the current research results of humanoid- arm bionics and parallel manipulators, an approach is presented for 7-DOF cable-driven humanoid-arm manipulator. Cable- driven mechanism is high in mechanism rigidity, control accuracy and loading capacity, which overcome the disadv- antages of conventional serial mechanism. The detailed mechanism of humanoid-arm manipulator is introduced firstly; and then the manipulator motion is described by screw theory, the motion ranges of shoulder joint are resolved under the tension conditions of the cables. To find displacement solutions of a 7-DOF redundant robot, a hybrid algorithm, based on GPM and Paden-Kahan sub problems, is proposed. The length of the driven rope can be solved according to the relationship between the joint angles and rope length. The coupling influences from shoulder to the wrist and the elbow joints are also analyzed. As the result, through the simulation of ADAMS, using the straight-line interpolation, real-time animation display is completed for the motion of the manipulator to verify the correctness of inverse kinematics algorithm.

Key words: Cable-driven, Inverse kinematics, Parallel mechanism, Screw theory