Characterizing reaction bandwidths in a position-controlled robotic arm

Abstract

Position-controlled robotic manipulators remain an industry standard but are ill-suited for guarded move approaches to advanced manipulation. Adding additional feedback with the expectation that a position-controlled system can account for it cannot guarantee successful implementation. To explore and define the limitations of position-controlled arms, I attempt to characterize different motion and force bandwidths of a large, 6-DOF robotic arm. Peak force and motion overshoot measurements were taken at varying speeds of the robot. These experiments showed that at speeds as low as 10 mm/s, the robot still exerted over 40 Newtons of force, enough to crush objects typically used for manipulation tasks. Overcoming these issues in using position-controlled arms are difficult to account for with software approaches, but different mechanical solutions can be envisioned to combat this problem in robotic manipulation.