Integrating geometric constraints into reactive leg motion generation

This paper proposes a reactive leg motion generation method which integrates geometric constraints into its generation process. In order to react given instructions instantaneously or to keep balance against external disturbances, feasible steps must be generated automatically in real-time for safety. In many cases this feasibility has been realized by using predefined steps or admissible stepping regions. However, these predefinitions are often too conservative or valid only in limited situations. The proposed method considers geometric constraints in addition to joint limits during its generation process and it can utilize the ability of the robot to a maximum extent. It can generate feasible walking pattern in real-time by modifying the swing leg motion and the next landing position at each control cycle. The proposed method is validated by experiments using a humanoid robot HRP-2.