Tension Analysis for a Cable-Driven 7-DOF Manipulator

A 7-DOF cable-driven manipulator is analyzed in the paper. First, according to the torque equilibrium, a static equation of the manipulator is deduced. Then, a dynamic formulation based on the static equation is followed, which includes the influence of external torque, gravity torque, inertial torque and gyroscopic torque. And then, an effective approach of calculating the external torque, gravity torque, inertial torque, gyroscopic torque and cable tension is obtained, which is simple to compute and its physical meaning is definite. Finally, the correctness of cable tension algorithm is testified by the simulation studies. Also, the elastic distortions of cables caused by cable tensions make the manipulator departure from its ideal trajectory and an error compensation is needed.