Unlike conventional opto-electronic devices such as light curtains or laser scanners, a safe vision system can monitor multiple areas and detect foreign objects (such as a finger, leg etc.) within the viewing area, rather than detecting that a "light beam” has been interrupted.
There are two types of safe vision system that will be available – safe cameras (such as PSENvip) for press brake monitoring and safe 3D vision systems (such as SafetyEYE) for area monitoring.
A 3D safe vision system can monitor an area in 3 dimensions, compared with typical opto-electronic protection devices such as laser scanners or light curtain, which are 2-dimensional monitoring devices. This means with a 3D system you can specify height, width and depth, creating 3D monitoring zones anywhere in the viewing are, and the zones can be of any shape.
Current safety-related solutions have their limits
These limits are especially noticeable when you consider the example of a robot workstation comprising one or more robots and protected by safety fences.
To be able to detect people entering the danger zone or remaining within it, the robots generally require additional protective devices such as light grids and laser scanners in conjunction with a gate entry interlock.
However, typical optoelectronic protective devices are unable to monitor zones, at best they monitor planes. If there is no visual contact then the workstation must also be protected using pressure sensitive mats. So uninterrupted monitoring of a robot’s operating range is only possible with a great deal of technical investment, if at all.
