"A useful Thesis for you may Michael James Brownlow - Oxford University 1993 - A Time-of-Flight Optical Range Sensor for Mobile Robot Navigation. Unfortunately I only have a hard copy - not pdf. "
"Did you consider the effort for designing a laser distance sensor from the scratch? Profound experience with medium fast, high
dynamic analog electronics is obviously required for it. At a somewhat lower signal frequency range, it's the same with ultrasonic
TOF measurement.
It's O.K., if the distance sensing point is your main project, otherwise, I would fall back on existing sensor solutions."
Hewhowalk said:I was hoping to find something like the one used by Neatorobotics.
FvM said:As an example of simple laser rangefinders state-of-the-art, see Bosch PLR25, which has an about 100 EUR retail price in europe.
It's said to give 2 mm accuracy over a 50 mm to 25 m range. There are possibly cheaper devices from far east companies.
I don't had hands on it yet, but I guess it's rather phase difference than pulse TOF.
There is, by the way, a principle difference between single frequency phase shift and pulse TOF measurement. Phase shift can
only give a scalar measurement, pulse TOF can (in principle) detect multiple reflections at different distances, e.g. when
measuring through a window.
The other problem with phase shift is that it is ambiguous after a certain distance depending on the modulation frequency. If the frequency has 360 degrees phase shift at 30m then 40m will produce the same phase shift as 10m. The usual way round that is two use two or more frequencies to resolve any ambiguity. The system I designed used 3 frequencies and while the first ambiguity was at 7.5m I could unambiguously measure over 400m.
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?