(A) study on the realization of dynamic gait for a biped humanoid robot

Abstract

Recently, many researches have been focused on development of biped walking robot similar to human walking. The objective of this thesis is to realize the dynamic gait for a robot based on an online sensory feedback control. For this purpose, we have developed the KAIST humanoid robot platform KHR-1 that is composed of 21 DOF (12 DOF for lower limbs, 8 DOF for arms and 1 DOF for trunk that has yawing motion) The first part of the thesis describes the design philosophy of the humanoid robot KHR-1, the selection method of actuators, and the elementary technology that is required in realization. The actuators of the lower limbs are selected by the simulation of specific motion patterns in the sagittal and lateral plane with a simple lumped mass model. For example, specific motion pattern in sagittal plane is a standing up and sitting down motion during single support phase, and this pattern is frequently observed in walking and going up the stairs. The validity of the actuator selection method is verified by real experiment. This paper also presents mechanism, controller architecture, motor amplifier, force/ torque sensor and tilt sensors of the developed humanoid robot KHR-1. The latter part of the thesis presents three online controllers for maintaining dynamic stability of a humanoid robot using force/ torque sensor. Those are damping controller, landing orientation controller and landing position controller. Since the legs of a humanoid robot are relatively long and serially connected with compliant force/torque sensor at the ankle, this architecture has the inherent characteristics of a lightly damped system. Most researches on balance control have overlooked the deterministic vibration caused by structural compliance. In addition, the vibration was not positively considered to improve the characteristics of the system. Therefore, a simple inverted pendulum model with compliant joint is proposed in this thesis, and the damping controller that increases system...