Finding the position of robots

Suppose we have 2 robots and wireless communication is not allowed between them. In a 2D plane how can we get the position of one robot w.r.t another?

You could scan and find the other robot with a sensor.

You could do wired communication using some clever system to keep the wire taught. I can imagine several ways of doing this. Range would be important for this.

Is all wireless communication not allowed for only some types? No communication that doesn’t use wires is incredibly restrictive. Couldn’t even do dumb stuff like flash a light and use an IR camera because that is probably communication.

You could try to coordinate the locations so well that the position of the other robot is not necessary.

By wireless communication it only meant not to use Xbee or bluetooth. What type of sensor are you talking about in the very first line of your answer. And also can you elaborate about the flash and IR camera system please. Any idea would help me a lot.

You basically have to use light or sound. Sound would probably be easiest actually. Think an ultrasonic (or not) pulse, you have all kinds of stuff to work with. Amplitude gives you distance, if you have multiple microphones that can possibly give a general direction.

There’s actually an anti-sniper system that works exactly like this, can detect where bullets are being fired from, check it out…

The system in the video is quite awesome. Does it involve sound recognition or anything. I’m unable to find any sensor. I found only an ultrasonic sensor which has a range of 4 meters. And i’m interested in a range of 10-25 meters. Can you suggest any tutorials or anything.

O ya we should all pretty much clarify, none of our discussion(outside my suggestion to use a massive wire) actually is possible with standard VEX parts. You are going to need some sort of additional sensors

Anything from a good camera that returns xy coordinates of objects it sees

To a simple IR beacon
In looking for a good cheap example of one of these I came across this which is amazing and might work perfectly for you. Actually this could have come in handy in projects I have done in the past and I might pick up a pair.