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[on:]

hey everyone,

I'm trying to do this project using an arduino board in which I can get it to navigate autonomously towards a series of RF beacons (each with a different frequency) but I'm having some difficulty establishing this.  for one, I don't know what kind of hardware I would need to interface the arduino board with in order to get it to recognize an RF signal. Lastly, I am not sure about what kind of RF beacon to make.  I'm really hoping someone can help with this

[Reply #1 on:]

Have you considered high power IR instead of RF.

That way you don't have to worry about directional antennae. A lot easier to implement.

[Reply #2 on:]

the problem is that I have no idea if something like that has already been copyrighted before (this is for an engineering senior design project)

[Reply #3 on:]

Well, there is very little out there that is completely original.

Ultrasonic sound beacons may be another option.

[Reply #4 on:]

doesn't that have very limited range and also works under a triangulation system?  I don't know how I would get that to work such that the car I have the arduino set up on would go chasing one beacon, then once it's close enough it would chase another one, etc.

[Reply #5 on:]

Yes, ultrasound does suffer from limited range, but it also has the massive advantage that it doesn't require licensing.

I'm not sure about allowing a car to autonomously navigate under control of such an underpowered platform as an Arduino.

[Reply #6 on:]

Going back to IR for a moment, getting a directional fix on a single IR beacon is not much harder than a light following robot technology, and you just need a couple of transistors for that -- I just did that

You could filter the signals coming into a pair of IR phototransistors for the carrier frequency of the beacon and if the left signal is stronger than the right, drive the right wheel forwards etc. and it will home in on the beacon.

Put a proximity sensor on the beacon so that when the robot car arrives, the beacon turns itself off and turns the next beacon on, so off the robot goes towards the next one etc.

If thats not good enough, and you want the car to be smart enough to know which beacons its visited, and have multiple beacons transmitting at the same time, then you are looking at a project that IMO is far beyond your, mine or the Arduino's capabilities.

[Reply #7 on:]

IR directional detection will probably be much easier than RF. You probably can get your IR "beacons" at walmart for $5. In the past I've tinkered with the walmart $5 universal remote controls (found at the checkout lines) for similar setups. Modify the remote control such that a simple timer circuit will activate the desired button on that beacon every second or so to send out its unique button code. The bot would need a directional IR receiver chip panned by a servo or similar to locate the current direction of the beacon, and then decode the modulation of the button press to identify the sending beacon.

[Reply #8 on:]

I think you have it zoomcat!

Probably don't even need the IR chip to pan, just have the car turn in a circle, then full speed ahead when it finds the right beacon.

Guitar dude - let us know what grade we get

[Reply #9 on:]

If one pans the IR detector, it might be possible to calculate a current position (relative to the beacons) of the bot by measuring the angle between the beacons.

[Reply #10 on:]

if you are really into it you could use the wiimote camera that provide the 4 most visible ir source if you are even more into it using two of them and you could map in 3d the distance to thoses point using a parallax methode