Safe adjustment regions for legged locomotion paths

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.