Online absorption of mediolateral balance disturbances for a small humanoid robot using accelerometer and force-sensor feedback

Sociable humanoid robots should be able to coexist with humans in human environments, where they will very likely have to face unexpected disturbance forces. In this paper, an online ankle-hip control strategy is presented that allows a standing biped robot to withstand a force in the mediolateral direction, using foot force-sensor and accelerometer feedback. The control algorithm is simple and can be implemented on any biped robot equipped with these sensors. Experimental results are presented for a small humanoid robot Fujitsu HOAP-1 showing that our method allows the robot to bear considerable perturbation forces.