A System for Speed and Torque Control of DC Motors with Application to Small Snake Robots

This paper describes a custom Low Power Motor Controller (LoPoMoCo) that was developed for a 34-axis robot system currently being designed for Minimally Invasive Surgery (MIS) of the upper airways. The robot system will includes three robot arms equipped with small snake-like mechanisms, which challenge the controller design due to their requirement for precise sensing and control of low motor currents. The controller hardware also provides accurate velocity estimate from incremental encoder feedback and can selectively be operated in speed or torque control mode. The experimental results demonstrate that the controller can measure applied loads with a resolution of , even though the transmission is nonbackdriveable. Although the controller was designed for this particular robot, it is applicable to other systems requiring torque monitoring capabilities.