Control strategies for tendon-driven manipulators

Two antagonist control algorithms are presented. These algorithms are used to control manipulator links antagonistically driven by two actuators via tendons. They have been simulated and experimentally shown to produce better active and passive performance for an electric test system than control algorithms developed earlier. There are two fundamental differences between the control algorithms and earlier ones. First, the new algorithms allow both positive and negative (push and pull) commands to be given to the actuators. Previous systems generated only pull commands, ensuring that tendons would not go slack and give rise to backlash and other problems. The new controllers allow push commands to the actuators, but still do not allow tendons to go slack. Second, each actuator, in addition to being fed back its respective tendon force, is fed back both positive nd negative manipulator joint torques. This feature allows both actuators to respond simultaneously to torque errors.<>