Allowable Maximum Safe Velocity Control based on Human-Robot Distance for Collaborative Robot

Recently collaborative robots which share the workspace with human attract much attention from the industry and the researchers. This paper suggests a method of controlling the velocity of the robot at the allowable maximum velocity to ensure human safety even when the distance between the robot and the person becomes inevitably closer than the safe separation distance. The allowable maximum safe velocity is calculated using the collision model which predicts the collision peak pressure and the peak force between the robot and the human in the case of collision. The pressure and force threshold given in ISO/TS 15066 is used to estimate the allowable maximum velocity of the robot as a function of the distance between the robot and the human. By operating the robot at its allowable maximum velocity the productivity of the collaborative operation can be enhanced without jeopardizing the safety of the human. The effectiveness of the proposed approach is verified through simulation results in this paper.