Study of dynamic biped locomotion on rugged terrain-theory and basic experiment

This paper introduces a new control method for biped locomotion on rugged terrain. The authors assume the ideal robot model which has massless legs. When a particular constraint control is applied to the ideal biped, the dynamics of the robot becomes completely linear. The authors call such motion the linear inverted pendulum mode and use it to develop the control scheme of the biped walking on rugged terrain. In the linear inverted pendulum mode, walking on a particular rugged ground is shown to be equivalent to walking on a level ground. It is also shown that the additional use of the ankle torque makes the control scheme robust and applicable to a real biped robot with mass legs. The authors built an experimental biped robot which achieved stable walking on a level ground.>