Control Architecture and Walking Strategy for a Pneumatic Biped Robot

The paper aims to describe the design methodologies and the control architecture of a ten degrees of freedom biped robot. The prototype realized is pneumatically actuated, and the legs size and dimensions are anthropometric with the human beings. The control strategy has been specifically designed in order to ensure a proper stability during the motion. In particular, a three level feedback loop controller generates the walking trajectories in a different way for the stance and the swing leg. In particular the stance leg is actuated through a simple but efficient force control approach based on a different interpretation of the Virtual Model Control strategy, while the swing leg is controlled through a set of parabolic trajectories generated during the gait. In other words the parabolic trajectories are generated directly in the operative space in order to take into account the basic walking parameters, like the step length or the lateral balancing. A set of preliminary experimental results are also reported.