Biped robot push detection and recovery

This paper presents a balance control approach for a biped robot by regulating COM position with the help of proper foot placement in response to external perturbation. The proposed approach detects present postural and stability state of robot through sensory data from Attitude and Heading Reference System (AHRS) and foot force sensors; and in case of external push, recovers the balance and posture of the robot by foot placement in appropriate direction. The foot placement is carried out using one of the alternative or rescue trajectories already available in the memory of the robot. The rescue trajectories are developed for both sagittal and lateral plane and the strategy for switching from current trajectory to the rescue trajectory and then back to the normal trajectory is discussed in detail. The proposed balance recovery approach is then implemented on a biped robot and is experimentally verified.