Light Curtain Lock Out

[janner_10]

Where scanners aren't fitted, we have 2x reset PB's. One inside and one outside. They must be pressed in order, inside then outside with a certain time period for the circuit to reset.

 

[BOWILLY]

As I read your concern, you are trying to guard against the reset/restart of a cell after someone has entered a dangerous area via a muted light curtain, correct? Instead of protecting someone inside the cell, re-assess the risk and try to prevent entry in the first place. Prevent access to the light curtain with an area scanner/radar outside the cell. You must engineer the cell so that human entry can only be done through a trapped-key protected man door.

 

[Holmux]

A You must engineer the cell so that human entry can only be done through a trapped-key protected man door.

It’s very common to have robot cells designed, for operators to enter true the light curtains, I have installations where operators enter the cell at least every 5 minutes, and from multiple sides.

This needs to be fast in and out, the only safety is the distance I have from the light curtain to the robot, if they run into the cell, I need to be able to stop or slow down, before the operator reach’s the robot.

I think I have tried every option, using: scanners, radars, thermal cameras.
The one I like the best is a dual light curtain, where you keep track of what direction the operator is moving, but when you have more then one operator entering the cell, this falls true as well.

So often it ends up with a single light curtain and operator IQ

 

[BOWILLY]

I've never seen a robot cell where people can access the cell via a light curtain. I've only seen maybe 50-100 cells so mine is a small sample size. Given that, your concern should have been captured during the risk assessment at the design stage.

 

[JeffKiper]

We did robot cells years ago where the operator interacted with the robot through a light curtain. We used 1 light curtain with a safe approach distance greater than the stop time of the robot.

We 2 area scannera mounted vertical for a forklift detection. The system would stop when the first area scanner was broken. The the second was no problem. If a person walked through the first and broke the second the system emergency stopped. There was enought distance between the 2 that you couldn't block both with a body.