Cartesian Trajectory Control of Humanoid Robot Arms Based on a Disturbance Observer

This paper presents an application of a disturbance observer (DOB) to the Cartesian space control of one of humanoid robot arms. Position tracking performance of the robot arm is improved by rejecting disturbance by an acceleration-based DOB(AbDOB). AbDOB utilizes an accelerometer to measure acceleration of the end-effector directly, uses that to form a conventional DOB structure, and cancels out disturbance. Experimental studies are conducted to evaluate the performance of the proposed Cartesian position control by an acceleration based DOB method.