Robotic testing of radio frequency devices designed for industrial safety

An experimental setup is proposed to test the performance of safety devices based on radio frequency technology. The setup specifically tests devices designed for improving safety in dangerous areas of small size, such as those surrounding power press brakes. Tested here is a radio frequency identification (RFID) prototype, whose main objective is to prevent accidents by sending a stop signal to a machine when a worker’s wrist, bearing an RFID tag, gets too close to the dangerous area. An ABB IRB 2400L robot is used as a reference system; this system is capable of providing millimeter accuracy. A plastic hand and a wristband with at least one passive RFID tag are attached to the end of the robot arm, which emulates the behavior of a human arm. With this robotic approach, it is possible to test trajectories with different velocities and orientations and to simulate several risky situations associated with machine use. Several experiments are presented that were conducted with the RFID prototype, and statistics are reported on the distance detection capability of this safety system with respect to the plane that defines the dangerous area. A matrix approach is proposed for analyzing the robustness of safety devices that are designed to automatically prevent a worker entering in dangerous areas. The results show the benefits that development of a radio frequency device of this class could confer towards increasing worker safety.