Abstract
This paper proposes a new dynamic gait control method of biped robot based on robust joint servo control. The method consists of two subjects. The first subject is the approximation of biped robot to the inverted pendulum for sagittal plane and lateral plane. The second subject is the constitution of dynamic gait control based on robust joint servo control and kinematics.
The motion description in Cartesian space is determined from the motion of the inverted pendulum for sagittal plane and lateral plane. Suitability of the biped motion reference is confirmed by distribution of ZMP (Zero Moment Point). Using the inverse kinematics of biped robot, the biped motion references in Cartesian space is transformed to the position references in joint space. In joint space, the robust position control system consists of two-degrees-of-freedom control system based on coprime factorization and disturbance observer. Since the robust joint servo control system compensates the inertia variation and disturbance torque on dynamic gait control, this control system is suitable for the dynamic gait control of biped robot. The validity of the proposed method is confirmed by the experimental results.
