Crane positioning

  • Thread starter Ludovic DEMEULENAERE
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Thread Starter


We are looking for a system able to measure the absolute position of a crane running on a 800m long way. This system shall run without any contact.

Thank you in advance for your help.

Crucius, Wesley

There are two decent solutions. Both use laser light reflected off of a special reflective target material.

1. Sick DME 2000/3000 VISIBLE Laser distance measuring unit (Yes, the manufacturer is "Sick", a German company). Resolution is 1mm, Accuracy
is ~+/-5mm beyond 10 meters or so, and much worse and non-linear inside 10 meters. Very reliable, serial/SSI interfaces, 10/100 samples/second.

2. Geotronics TCS INFRARED Laser position controller(A Swedish company, I believe). This one is intended to actually close a position loop and provide a +/- 10V Analog Velocity command signal to a drive. Not so reliable in the past, serial interface (absolute/relative position
command), something like 30 samples/second.

I have a lot of practical experience with both of these units and have evaluated many others, so if you have other questions, don't be afraid
to contact me directly...

Feldman, Ward

What will be the resolution for positioning? Have you thought about using lasers? I have been working on a similar project without any contact and we are looking at using lasers.
And on the top of these, if you don't have enough information on the dynamics of the system, then fuzzy logic will be quite a sound approach for controlling.


Thanks alot for your quick answer. We already know Geotronics TCS product and we are using it in the case where we only have one crane on the rolling way. But the problem is that we have 4 cranes on the same way and it is not physically possible to place one TCS per crane because we do not have enough place. In the meantime we have found a product made by STEGMANN which consits of metal bars and a sensor. Inside the metal bar there are some different magnets which correspond to an absolute position. This system could solve our problem but we have to test it to check if there are no interference with the magnetic fields (~50 Gauss) of an aluminium smelter factory.
You are talking about other solutions, what are they ?

Crucius, Wesley

I think Stegman is actually a data encoding scheme, not a product line, but I guess I misinterpreted what you meant by non-contact. I have used something that is similar to what you described (it's called Stahl-Tronics) successfully before, and think it is a good product. Another solution along the same lines would be a custom Temposonics implementation where instead of a single magnet on the moving object, you use a linear array of stationary
magnets placed at varying but well defined distances from one another and put the Temposonics sensor on the moving object. One problem with these types of solutions is that you may actually need to take thermal expansion/contraction of the "encoding" medium into consideration given your long distance. My
comment about other solutions really referred to a number of other Infrared and Visible Laser based products.

Helmut Meissner

we use for our Robots in concrete pipe handling Incremental or absolut encoders with a tothwheel in a triple chain. In one of our customers
plants they use a system simular to the Stegmann system. If heared of a system reading the informations opticaly from the metal band.


Helmut Meissner

Larry Kolbert

Another source for you to consider is ThermoMeasureTech and their Accu-Pulse laser system.