Improving Safety in Collaborative Robot Tasks

Abstract

In recent times, there has been significant interest in collaborative robots where the tasks performed by a robot are non-repetitive and complex, and humans and robots share an overlapping workspace. In such a case, the robot controller must necessarily be safety-aware. In this paper, we propose a mechanism to evaluate a robot program and compute a safety score for each action that the robot is about to perform. To this end, we have implemented a code analyzer that examines the robot's Move instructions and assigns a safety score. A subjective logic based approach is used to compute the safety score for each instruction. We have evaluated the approach through ABB's RobotStudio <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">®</sup> simulator. We simulate two scenarios: First, where two robots share a workspace and second, where a robot moves along a path with an obstacle. The simulations show that using our code analyzer and safety score formalism; it is possible to evaluate the application code for safety and enable avoidance of potentially unsafe behavior.