A new method for sensorless collision detection on the servo level

摘要

Physical human-robot interaction is one of the hottest topic in robotics and safety issues are its fundamental aspect. The present paper contributes to this aspect in that collision detections can be completed on the servo level in an intuitive way. The principle of the proposed collision detection strategy is based on the relative difference of the feedback commanded torque, which is able to identify the abrupt change in the feedback commanded torque's slope during collisions. Under the assumptions that the planned motion is smooth enough and that the gravity with respect to the joint variable is continuous, the detection strategy presented here can work fast and efficiently. A prototype with one degree of freedom (DOF) has been built to verify the given approach. Experiment results reveal that the proposed method is valid in different situations. In addition, since no external force/torque sensors (F/T sensors) are needed in this process, the proposed method is also economical.