Joint impedance control of a stiffness adjustable tendon driven anthropomorphic hand

Abstract

The DLR Hand-Arm-System is the first component of a new humanoid robot which is as robust and anthropomorphic as possible. Each joint of the system has an adjustable spring mechanism, which enables to adjust the mechanical stiffness. Additionally, the springs increase the mechanical robustness of the system against impacts. In this thesis the compliance control of the hand of the Hand-Arm-System is developed. A control unit is implemented, where the user can set the desired joint positions as well as the desired joint stiffness. The controller remains predictable for any input, because a state machine monitors the system. The mechanical as well as the controller stiffnesses are set in the system such that the desired effective stiffness in the joints is achieved. The system model is verified with experiments on the real system and the control unit is validated regarding the user specification.