How much longer was it the last time you looked?33 kHz was a little longer last time I looked.
How much longer was it the last time you looked?33 kHz was a little longer last time I looked.
This has been a holy grail for years. Sorry, but it ain't gonna happen.I want to model self driving cars. since GPS is not accurate, i was wondering if you know of any tutorials to build an accurate triangulation setup or kits i could buy for less than $100? IT should be accurate within a few centimeters
So you are saying that the speed of sound and the speed of light are the same?The last time I looked, 30 kHz had a wavelength of 10,000 meters. 33 kHz should be just shy of 10,000 meters.
For a 1 cm wavelength, the frequency should be 30 GHz.
And how many such detectors would you need in order to determine the toy car's position to within a couple of centimeters in, say, a 12' x 12' room?Why not a grid of hooded IR detectors in the ceiling? With an IR transmitter on car, pointed straight up?
I think this is going to run in a huge problem. In using the relative signal strength, you are assuming two things that are very poor assumptions -- that every emitter is very uniform over every possible orientation relative to any of the emitters, and that every detector is very uniform in its sensitivity from every possible incident path. In addition, you have reflections that are going to be seen by the detectors that will corrupt the signal-strength measurements. Since you are looking centimeter scale resolution, your differential signal-strength measurements need to be sensitive to about the resolution commensurate with the IR beam spreading out over the course of one more centimeter of travel.No, with a single 360 degree hemispherical emitter and three wide-angle detectors at the periphery.
Three points determine a plane, and the intersections of three spherical coordinate vectors determine uniquely any point in the plane, including points outside the closed space determined by the detector locations. To make it easier, put one detector in each of the room's four corners with 90 degree fields of view. Now, all valid locations are within the plane's internal boundaries. You don't need to know the incident angle of the signal at each detector, only the relative signal strength. Start with the dimensions of the detector rectangle, add a butt-load of high school trig, and shake well.
ak