Torque and Force Controllers for a Biped Robot

Kurzfassung

In this work we provide a comparison between admittance controllers based on force sensors in the feet and impedance controllers based on joint torque sensors. We start by analyzing to which extend the findings from robot manipulation apply also to biped robots, in which the interaction between the robot and the environment as well as the respective sensing occurs at the robots support. In this context, the role of a free-floating base link in biped robots as compared to the fixed support in manipulator control is analyzed using simple dynamical models. The comparison is supported by several experiments, both in simulation and on a real robot. The chosen task is the balance of a biped robot in presence of external perturbations in different directions. The simulations are based on OpenHRP3 and experimental results were obtained with the DLR biped.