Anti-Collision Detection on a Mining Unit

[goldyvb]

Hello All,

I am working on a series of 3 mining units which are not mechanically connected (i.e. about 3m apart) but need to move in together at the same time. They are each about 3 stories high and 50m long and move along on caterpiller tracks and are fully manually operator controlled. The trouble I am having is finding an instrument (an economical one at that) that will detect if the units get too close to each other and trip the caterpillar drives to prevent a collision. Previously I have used small ultrasonics for short range detection on a ship loader to detect if a car was parked on the rails, but that was years ago and I have had trouble finding a similar instrument. As they are not connected, they can also skew over various angles so the system I chose would need to accomodate this.

An additional function (although can be engineered out separately so not essential) would be to detect if they got too far apart so as not to stretch the interconnecting pipework and cables.

Thanks for your input in advance!

Cheers

Goldyvb

 

[ScottyUK]

http://www.sick.com/gus/products/product_catalogs/industrial_sensors/distancesensors/en.html

----------------------------------

If we learn from our mistakes I'm getting a great education!

 

[goldyvb]

Thanks ScottyUK. I do like the Sick gear, but this environment is very agressive and I am steering clear of anything that uses optics, hoping more to use something that uses ultrasonics or radar or other?

 

[IRstuff]

For 3-m gaps, ultrasonic sensors are also applicable:

http://www.hexamite.com/products.htm

http://www.juddcom.com/#Depth

TTFN

FAQ731-376

 

[Comcokid]

You might look into using one of the non-contact radar level sensors that are used to measure contents of fluid tanks and grain silos. They are designed to be rugged, and to measure in dirty environments. Some of these devices are made by suppliers who can provide a lot of application support for your off-use environment.

 

[danw2]

Our local ISA group toured a coal fired power plant a decade ago, and I clearly remember Milltronics ultrasonics used for positioning tripper cars over coal bunkers. But a scan of the Siemens web site's industry notes

http://pia.khe.siemens.com/index.aspx?nr=14680&dis=show_application_pi&ps=8

(Siemens bought Milltronics some years ago) fails to find any reference to the use of ultrasonics for anything but 'level'.

I suspect that any rep who handled Milltronics before it was Siemens might understand how to do it.

 

[roydm]

Ultrasonics may be Ok provided the target stays in line when turning corners etc.
How about something simpler like a bungee cord / pulley system connected to a display to indicating the separation gap. A pointer fixed to the cord against a scale where the operator could see it indicating the gap distance . You could also include a proximity switches that would shut down the leading unit's drive as the tension indicated too much gap or the trailing unit if the gap was too close.