[chbot] Localisation Project

[Robin Gilks]

> At our last meeting Robin was talking about how to determine his robot
> position with cm accuracy in a field.
>
> This project using ultra wideband radio might be an answer:
>
> https://www.kickstarter.com/projects/pozyx/pozyx-accurate-indoor-positioning-for-arduino

This looks very interesting indeed. I've yet to play with the RTKlib stuff
and the pair of GPS receivers I already have that *should* provide 2cm
accuracy but I'll certainly bookmark this!!


> Robin also spoke about using two scanning laser beams. A laser device that
> emits a time coded line might be easier for a photo detector to receive
> than a pin point beam:
>
> http://www.aliexpress.com/item/Portable-Laser-Edge-Straight-Level-Line-Horizontal-Vertical-Guide-Measure-Tool-51112/32368588246.html
>
> There are lots of similar devices in the $5-$10 range, some with two
> emitters.

This looks like a simple laser emitter and a diffraction grating - with no
innate measurement capability. I have a spirit level with laser and
diffraction gratings for horizontal and crosshair lines, I'll see how
'wide' the dispersion is to see if the 90 degrees coverage from a  corner
of an orchard could use this type of device.

I have a laser measuring tape, the problem has been what to point it at
when trying to determine position!

-- 
Robin Gilks
Internet: robin at gilks.org    http://www.gilks.org
Tel:      (+64) (3) 347 4370