Following rc toy

I would like to modify an RC car so that it follows me - or at least a kind of 'beacon' i carry, like those following suitcases (they work with bluetooth).

The beacon can be anything that fits in a pocket or on a holster clipped onto my belt.

I thought about a two-part sensing - the first part is direction, the second one is distance.

For the direction I could imagine an array of IR receivers arranged in a semi-circle separated by some opaque material. Depending on where the beacon (IR diode) is and because of the opaque material between the receivers, only a few IR receivers can detect the signal and the direction can be infered.

The distance part could be an ultrasonic sender and receiver pair. Not only does the beacon send an IR signal, but also an ultrasonic one in regular intervals. The time between two signals can be converted in distance.

My question is: Is this project feasible? Can the IR array be built in a way so that it can actually detect the direction? Does something like a two-part ultrasonic sensor exist? I only found sensors like the Ping))) which has sensor and receiver on the same board interacting with each other.

What other ideas for the sender/receiver part do you have?

An alternative approach could make use of computer vision. The beacon in this case would be some predefined object (coloured shape, IR LEDs like in a Wii,...) and the sensor would be a camera.

Your ideas look fine to me :-)

Separate IR transmitters and receivers should be available for e.g. IR remote control. With both IR and US transmissions you may have to add the circuitry and/or code for sending and decoding pulses.

Measuring a distance by US requires synchronization between sender and receiver. Eventually you can use the same pulse source for both IR and US, so that the received IR pulses correspond to the sent US pulses as well.

There have been numerous "follow me" discussions in the past, but most did not go anywhere. You might check the below video for a possible solution.

Synchronization is a good point. Makes things easier as opposed to a known interval between regular pings.

The idea of TWO ultrasonic receivers and one sender (in the video) is brilliant. I think I'll look into that. However, I have no idea how they modified the ultrasonic modules.

Did they just unsolder one of the two metal cups?