A biped locomotion strategy for the quadruped robot Sony ERS-210

We describe the design and implementation of a biped locomotion strategy for the robot Sony ERS-210 (AIBO). Being designed for quadruped gaits, this robot has several limitations which make biped locomotion a challenging task, such as passive feet, a high barycenter in the erect posture, and relatively weak actuators. We have therefore chosen to fully exploit the double support phase, in which the robot has both feet on the ground, in order to achieve the correct take-off conditions for performing the single support phase. During the latter, the mechanism motion is essentially uncontrolled but can be predicted and planned using a simple equivalent mechanical system. Both simulation and experimental results show the positive outcome of our study.