Improving Active Accident Prevention in Robotized Manufacturing Plants

Abstract

This work describes the design strategy and preliminary testing of an active protection system characterized by low-cost commercial sensors of proven reliability. In the system, each risk level is defined and a particular robot reaction assigned to it. The risk calculation is based on the recursive solution of the manipulator's kinematic problem for the evaluation of the horizontal distance components and the relative speed between operator and machine. Computational effort is minimized, since (1) the protection system procedures can be performed directly in the robot controller with the robot kinematic and dynamic calculations and (2) only the cylinder-shaped volumes around the operator's estimated position have to be defined in order to perform a probabilistic evaluation of the risk levels. Preliminary testing on a simplified setup has validated the system's reliability, its insensitivity to background disturbances, and the ease of use of the sensors.