High stiffness torque control for a geared DC motor based on acceleration controller

The authors propose a torque control method for a geared DC motor with the ability to improve the structure stiffness reduced by the torque sensor. One of the special features of the proposed method is that it introduces an acceleration controller and positive feedback of the link angle through the inverse dynamics of the acceleration controller. The acceleration controller is realized by a disturbance observer which estimates the total sum of the disturbance torque imposed on a motor axis, and an acceleration controller is necessary for good performance of the positive feedback of the link angle. The effectiveness of the proposed method was demonstrated by experiments using a single axis geared DC motor system with a torque sensor