Motion stabilization using laser distance sensor for biped robots with flexible joint

This paper describes an approach of motion stabilization by using laser distance sensor for biped robots with flexible ankle joints. For avoiding the vibrated zero moment point(ZMP) behavior due to the mechanical resonance, the vibration control method is proposed in the paper. The deviated center of gravity (COG) due to the ankle's deflection is measured in real-time by laser distance sensor, and equivalent reaction force relating to COG deviation is used as feedback signal for vibration control. The reaction force feedback also enables the regulation of the compliant property of the robots. Therefore the proposed approach is suitable to stabilize the walking behavior including the impact between foot and floor environments. The validity is evaluated by several experimental results.