Indoor tracking device

I work in a large manufacturing facility (about 3/4 mile by 1/2 mile).
One of the problems we frequently have is that forklifts and industrial trucks used by our skilled trades are moved by one person then can't be found by the next person who needs it.

There are lots of obstructions and lots of noise and GPS signals do not penetrate the roof because of all of the metal trusses in the ceiling.
Any ideas for a possible Arduino tracking system?

Any ideas for a possible Arduino tracking system?

You need to have an understanding with the employees that the equipment needs to be returned to its designated storage location when they are finished with it. Make it a condition of employment.

Use fiducial markers on the ceiling and an upward-facing camera to locate those markers. It could be done with a Raspberry Pi, the Pi camera, a USB wireless device, and reacTIVision for the image recognition of the fiducials. Aside from the wiring to power the Pi you'd just be left with some basic programming to get the Pi to report it's location to a central server.

I like the idea of markers in the ceiling because it could work in theory. It is a good idea.

However it would be very difficult and expensive to put that many markers on the ceiling. I think each 50 ft x 50 ft bay would need one and there are more than 1000 bays. Part of my objective is to do this somewhat inexpensively. Also the ceiling does not have flat surfaces and is full of obstructions that would make it hard to draw a flat object that could be seen from many different angles.

I know commercial industrial systems exist for sale that use RFID readers positioned in a grid across a large area, but these systems are somewhat expensive, unless maybe I could make something like this myself.

There is wifi throughout the plant. I wonder if that could be utilized to determine approximate location.

Ideally I could come up with a solution that would require just 3 signal emitters positioned throughout the plant to triangulate the position of my tracking devices.

As for creating a new "condition of employment," that is much more easily said than done as conditions of employment are negotiated at the national level and even the existing conditions of employment are difficult to enforce. We have a difficult enough time making employees come to work on time (or at all), come sober, not leave hours too early, do what they're told while they're at work, and not steal company tools and equipment when they leave. Whenever we do decide to enforce any of these rules we have to bring with us at least 2 members of management and a Union committeeman to observe and agree with our conclusion that a rule has been broken. If we can get all of that to happen the employee will get a slap on the wrist like some sort of mark on their record with no real punishment, then all of the other employees will punish us by working at half their usual speed or slower for usually about a week. I could potentially get them to follow the new system if they like the idea and want to do it, but I think it would be easier and useful to have tracking devices that I could easily place on equipment that I want to track.

Here are some links describing commercial indoor tracking/locating systems, which use building wifi:

http://www.navizon.com/

of the mentioned businesses, indoo.rs offers some limited services for free:
http://indoo.rs/

As for creating a new "condition of employment," that is much more easily said than done as conditions of employment are negotiated at the national level and even the existing conditions of employment are difficult to enforce.

The quality of products you produce are probably of the same quality as your employees.

If there are people around the machines you want to track then one option is to install a siren which can be triggered remotely. If you're near by, you may be able to hear it directly. If you aren't, there may be other people nearby who can hear it and contact you to turn that damned noise off. Perhaps you could combine that with some sort of intercom mounted on the vehicle which people could use to contact you. If it worked, this might have a knock-on effect that people would be reluctant to have these machines left in their work area because of the nuisance factor when the siren goes off. That might be a good thing.

Put one of the little coin slots on the forklifts. The driver has to return it to retrieve his coin.

It works very well with supermarket trolleys.

...R

Bottom line, the company needs to obtain an HR/legal team that knows how to write a labor contract.