3-D biped walking over rough terrain based on the assumption of point-contact

This paper describes a 3-D biped walking over rough terrain. The robot is modeled as the special 3-D inverted pendulum that can change the length. The dynamics of the 3-D inverted pendulum is modeled as 2-D autonomous system by applying the Passive Dynamic Autonomous Control (PDAC) that is based on the assumption of point-contact of the robot foot and the virtual holonomic constraint as to robot joints. We analyze the stability of the 2-D autonomous system by use of Poincarée map, and derive the stable range over rough terrain. By applying the virtual compliance control to an actual robot “Gorilla Robot III”, the angle of the pendulum is modified. Finally, the 3-D biped walking over rough terrain is realized by use of the Gorilla Robot III.