Reflex control of biped robot locomotion on a slippery surface

Biped robots are expected to walk on many different and previously unknown terrains, and thus they may walk on a slippery surface with low friction with no information on the surface a priori. Any fall-down due to unexpected slipping could cause costly damage to the robot and thus should be avoided. The paper proposes a reflex control method for biped robots to quickly recover their posture from a slip soon after a detection of the slip. Computer simulations with a 12-DOF biped robot and a 6-DOF environment model that consists of nonlinear dampers, and linear and nonlinear springs, show that the proposed method is very effective in preventing a fall-down of biped robots on a slippery surface.