Generalizing torque control concepts

Torque control methods widely used for flexible joint robots to variable stiffness robots, the DLR Hand Arm System (HASy), are discussed. The presented control method extensions for VSA robots show promising performance. The active/passive Cartesian impedance scheme combines the best of active impedance control with the beneficial mechanical properties of passive compliant elements. The handling of task hierarchies helps to cope with the kinematic redundancy. Again, the formulation of collocated variables by potential energy shaping is an important cornerstone. Based on the presented method, results from research on the hierarchical control design for torque-controlled robots can be transferred with ease. The controller allows for link-side position regulation, thus rigid body planning can be applied. Well-damped robot motions can be executed with high precision and repeatability.