Safe adjustment regions for legged locomotion paths

Abstract

Balance and stability are critical issues for a humanoid robot, and various different strategies have been employed to increase their robustness and respond to disturbances while walking, such as adjusting the torso's trajectory, or changing the foot's touchdown location. In the presence of obstacles or rough terrain, however, changing the touchdown location can be dangerous, causing collisions or unstable support configurations. This paper describes the a method for integrating this sort of touchdown location adjustment with foothold evaluation from footstep planning approaches. We compute safe adjustment regions, which inform the walking controller of a legged robot how much a particular step through rough terrain can be adjusted yet remain safe. Results are demonstrated on a prototype humanoid robot.