Robot positioning system concept

Projects General Guidance
1

I am thinking of a way to keep a robot within the boundaries of a large property. this is not about determining longitude and latitude, this is about determining position relative to the property boundaries. not concerned with the vehicles heading, that's a different project.

the first stage, a proof of concept test, would go like this:

The Venue Infrastructure

  • A rectanglular flat floor.
  • A pole at each corner
  • An IR LED strip at each pole, mounted vertically
  • LED strips connected to any random IR remote, which has a switch to keep it transmitting one command constantly.

the only requirement from the remotes is that each one transmits a different bit sequence than the others.

The Robot Infrastructure:

  • a flat platform on top
  • with a stepper motor
  • spinning a parabolic mirror, half a pipe, not a dish, with an IR sensor at the focus

the plan is:

  • mirror spins, reads what LED string A puts out, notes stepper position
  • mirror continues to spin, reads what LED string B puts out, notes stepper position
  • mirror continues to spin, reads what LED string C puts out, notes stepper position
  • mirror continues to spin, reads what LED string D puts out, notes stepper position

then you do some surveyor trigonometry and calculate where you are in the rectangle, based on the angles to the sensors.

My questions:

  • could you modulate an LED strip with the 38khz from an IR remote?
  • could you read that quick enough to make things work? I am thinking 1 - 10 RPM for the stepper motor
  • has anyone tried a parabolic reflector with an IR sensor, to determine the range available?
  • has anyone tried making an IR sensor strip, to increase the chance of catching a signal?
2

Perhaps look at how robot lawn mowers work.

3

There are many successful variations on using fixed beacons for indoor localization, so the idea works.

Your mirror idea should work, but getting the focus and horizontal/vertical positioning correct may take some effort.

You could consider the Pixy camera with IR beacon modifications. Since the Pixy is a color sensitive position detector, variously colored LED beacons would work, too.

Pozyx uses radio beacons, and is Arduino compatible, but pretty expensive. Indoor positioning is a hard problem.

4

For stepper motor control while handling other inputs see my Multi-tasking in Arduino tutorial.
It has a complete stepper motor example controlled by user input and a sensor.

5

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