Tracking an object

[RustBucket]

At the risk of sounding completely stupid, I have a question...

I need to create a system that tracks an object. I.e as the object moves through the system, I want to be able to plot it's motion in 3D from the data I collect. Also, There's only one such object, and it has a transmitter (Radio frequency) built into it.

I'm very new to hobby electronics. I usually work with software, so please excuse any mistaken assumptions I would have made.

I would like to know how to design a reciever that gives me the DIRECTION from which the transmitter is transmitting. I think If I have three such recievers, I can triangulate the objects position in 3D. Am I right about this? If so, how can such a transmitter and reciever be designed?

Further, I need to collect this data on my PC. I think I need an ADC to connect these three tracking recievers to my serial/parallel ports. Once I have this data, I think I can manage plotting it's location on my PC. How can I do this? What ADCs do you advise me to use?

Any help would be appreciated. If you think I'm biting off more than I can chew, please point me in the direction I should start from. I've designed radio transmitters and recievers before, but never anything which calculates direction.

Thanks in advance

 

[Klaus]

You want to do it in 3D (x,y and z)? 2D would be much easier if you want to build it.

The radio amateurs used to (perhaps still do - I'm not active these days) play a game called 'fox hunt'. The 'fox' was a small battery operated transmitter sending a steady morse code signal. The hunters had receivers and antenna's in their cars, the idea was to find the fox after somebody hid it in town. The antennas got very clever, they started using automatic, roof mounted rotating directional antenna's to give them a directional fix on the move rather than having to stop every so often and do triangulation with hand held directional antenna's.

How large a detecting area did you have in mind?

 

[RustBucket]

Very small actually, probably the size of a room (10 feet X 10 feet X 10 feet)

 

[Klaus]

Now you got me curious, what exactly is the 'object'? In such a small are it could be traced visually unless you are talking about a rabbit down its hole :wink:

 

[RustBucket]

The object is a basketball It can easily be tracked visually, but what's the fun in that?

Actually, the point is to design a system that automatically follows one "tagged" object in a room. I can see many uses (automatic cameras, for one)

 

[Klaus]

Well, perhaps you could look into how satellites detect moving objects (like GPS receivers or EPIRBS) and use a similar technology with 3 fixed low power transmitters at the room perimeters. There would be a lot of number crunching involved to calculate the object's location, something way out of my league. Surely somebody has done work along this line, Google should uncover it if you ask it the right question.
Have fun

 

[RustBucket]

I've been looking through the internet, and I see a lot of circuits that give higher and lower beeps based on the direction you face. From what I understand of these, they have to keep moving to locate an object, but they work best if the object is static

Is it possible to adapt these to locate the direction of the object, while they stay still? One obvious solution is to have them rotate and scan the area, and then based on signal strength, locate where they are, but this seems really difficult to implement on a small scale. Any other ideas?

I was aso thinking about using Signal Strength detectors. Very similar to the above but if I had three of them, one on the X, one on the Y, and one on Z axis, I would have an approximation to the actual coordinates of the object. Is this correct?

 

[aevans17]

I also dont know alot about electronics, but it seems to me that the simplest way to do this would be to use a GPS tracker. GPS can give you accurate data for Altitude position triangulating through different satelites. I don't konw how much GPS trackers cost, or how you would interface with them, but they send you data via serial and all you have to do is read it. Check google for a GPS transmitter receiver. The math to do triangulation is easy if you can easily tell in what direction the item is from each sensor. However, if you are simply testing signal strength from say a rotating receiver to see what direction the triangulating sensor is reading then you will have your work cut out for you.

 

[RustBucket]

What is the accuracy of a GPS reciever? I thought it was too low for a small space such as this.

And yes, the math is easy, but I'm having trouble locating a circuit for sensing direction. Any help will be much appreciated