A fast Collision Detection System based on an Extended State Observer

Abstract

Safety of collaborative robots is guaranteed through fast collision detection methods able to reveal impacts occurring in any part of the system. This paper proposes a new impact detection method based on an extended state observer. It does not require torque sensors and, differently from analogous sensorless approaches, it exploits the high order derivatives of the system in order to reduce the detection latency time. Such derivatives are commonly not measured by the manipulator sensors, so that a Kalman Filter was required for their estimation. The performances of the novel Impact Detection System (IDS) have been experimentally tested on a planar robot and results have been compared with ones achieved through two well known alternative strategies. The proposed algorithm allows faster detections and it is robust w.r.t. noise.