Humanoid robots are meant to take over task which are dangerous or too physically demanding for humans. To accomplish this, the robot must be able to balance robustly in challenging terrain as e.g. stairs, industrial ladders, or debris. In order to gain more robustness, the robot can use multiple contacts (not only the feet but also the hands) to support itself.
image/text credit: DLRRMC
This video contains several experiments with the humanoid robot TORO developed by DLR, which demonstrates the performance and robustness of a passivity-based balancing controller utilizing multiple contacts.
An in-depth discussion of the method is presented in the paper ‘Passivity-Based Whole-Body Balancing for Torque-Controlled Humanoid Robots in Multi-Contact Scenarios.The robot creates a passive and compliant behavior for regulating the center of mass location, hip orientation and the poses of each end effector assigned to the interaction task.
TORO will be used mainly for research on control oriented problems related to whole body dynamics, we decided for rather simple but robust prosthetic hands. These hands allow for robust interaction with the environment, but would be limited in terms of dexterous manipulation.