It looks like robots are here to stay: Significant increases in microprocessing power and recent strides in automation and control technology have made robots mission-critical industrial tools. While many robots contribute to worker health and safety, two fundamental attributes — the power to handle super-human payloads and the flexibility enabled by full range of motion — pose potential dangers to people, especially if a fault or failure occurs. To address the increasing safety needs of robotic systems, a team of experts is working to establish new safety standards through the International Organization for Standardization (ISO) for robots and robot systems integration. Once the standards are confirmed, the U.S. Robotic Industries Association (RIA) is expected to update ANSI/RIA R15.06 to comply with the new ISO criteria.
Among the updated standards are first-time safety requirements for four major robotic technologies, including cableless teach pendants, human-robot collaboration, robot-to-robot synchronization, and vision-based safeguarding systems. Traditionally, a cable connected the robot controller to the teach pendant. New wireless technology eliminates the cable, reducing the risk that operators could trip over the cord or become entangled with other equipment. Cable-free technology permits the teacher to be in close proximity to the robot during the teaching function. Eliminating cables also helps reduce installation and maintenance costs. To prevent confusion about which pendant controls a specific robot, the new ISO standard includes requirements for unique identification of cableless devices; only one cableless pendant can be used per robot to prevent unintended operation of another robot.
New software-based safety systems can slow a robot to a safe speed or otherwise direct a robot's motion to a safe position or state, allowing people to share the same workspace with less risk. Collaborative robots, often called “cobots,” work closely with people. For example, with the new safe-speed technology, a robot might lift and position a heavy sheet of metal while human hands weld parts onto the larger piece. In addition, development of environmental awareness sensors allows cobots to “see” their human coworkers, triggering them to go into a safe position or safe state and wait until the human moves out of range and an operator resets the motion.
A new 3D safety-rated vision intrusion system can keep robots and people separate in the workspace without the costs and hazards involved with perimeter fencing. This electronic perimeter guarding system includes three video cameras mounted overhead in the work cell, which detect when someone enters the hazard zone. The system then visually or audibly warns the intruder about the danger. Controls also signal robots in the space to slow down or stop, thus reducing risk. Once the hazard zone is clear, robots are reset and operations can safely resume.
Tips courtesy of George Schuster and Marvin Winrich, Rockwell Automation