Virtual zones safeguard robots, co-workers

Ashley N. Paddock, ashley.paddock@photonics.com

A new imaging system monitors workplace environments to help employees and industrial robots, which typically work separately, to collaborate more closely on assembly jobs.

Robots that assist humans at work are enclosed by a protective barrier. To prevent injury, industrial safety regulations permit contact between people and robots only under certain conditions. For the two to act as a team, they must operate within an environment that defines safety zones.

The system is called ViERforES, or Virtual and Augmented Reality for Maximum Embedded System Safety, Security and Reliability, and was developed by researchers at Fraunhofer Institute for Factory Operation and Automation IFF. The system works with projectors and cameras mounted onto ceilings. The safety zones are clearly projected onto the floor or wall as visible lines that humans can recognize.

By sensing when these projected lines have been disrupted, the cameras detect when a safety zone has been entered. During an intrusion, the robot will slow down, and additional optical and acoustic warning signals can be issued. The researchers noted that the system offers flexibility as to the shape and size of the marked area. For instance, the designated safety zone could be defined by a circle, rectangle or any free-form contour.

Because standard components are used for the system, it is cost-effective, and the camera and projector are calibrated and synchronized to one another, said Norbert Elkmann of Fraunhofer IFF. In addition, he said that the system could be combined with robotic controls to dynamically modify danger and safety zones.

The monitoring system operates with modulated light, which Elkmann says is reliable even under the influence of external light.

The system also could be employed for monitoring public building security.