Conventional robot safety systems rely on components such as safety fences, light curtains and pressure sensitive safety mats. But showgoers at the Assembly Technology Expo, Sept 25-27 in Rosemont, Ill., got a look at a new approach to safety that has potential to eliminate these multiple components, while also reducing robot downtime.
The SafetyEye from Pilz Automation Safety L.P, a German vendor with U.S. headquarters in Canton, Mich., relies on a three-camera sensor that is mounted above the robot work area. Billed as “the first safe camera system for three-dimensional zone monitoring,” the system was developed by Pilz in conjunction with DaimlerChrysler.
The SafetyEye works by using three cameras that provide image data from the area being monitored. An analysis unit uses image processing algorithms to define the exact position of objects three-dimensionally. This information is superimposed on various “zones” that can be configured by the user on a personal computer. A person or an object moving into a warning zone surrounding the robot work area could trigger an alarm and cause the robot to slow down, for example, while an intrusion into a detection zone closer to the robot work area could be programmed to shut down the robot.
Compared to conventional protective devices, the SafetyEye requires less factory space, says Eric Hollister, a Pilz application engineer who is responsible for SafetyEye business in the United States.
The system’s use of multiple safety zones representing differing degrees of danger will also reduce downtime, says Hollister, because a zone violation does not always automatically trigger an emergency stop, as with other approaches. If a worker infringes a detection zone at point that the robot would still take several seconds to reach, for example, the system’s control technology can ensure that the robot’s speed is significantly reduced. If a warning then alerts the worker of the danger, and the worker steps back, the robot can then return to normal speed.
Other advantages of the system include the ability for users to quickly reconfigure and redefine detection zones as needed when factory equipment changes are made.
Robotics is the initial target market for the SafetyEye, says Hollister. But he sees potential for the technology “in any area where people move in and out.” The SafetyEye will be available in the United States during the first quarter of 2008, Hollister says.
Pilz Automation Safety L.P.