Electronics > Projects, Designs, and Technical Stuff
Brainstorming about bachelor thesis project - Data transmission using car lights
(1/4) > >>
97hilfel:
Hello everybody,
I'm a computer science student that has an EE background, thus I choose to do a bachelor thesis about the viability of a data channel for cars using their lights.
I know this has already been done in some way, for example, LiFi but I am not certain if that would also work in my environment.
The basic setup is to modulate the light of the car and pick it up with some kind of camera or sensor. The idea is that a car authenticates itself using its light to another car via its led taillights and the car behind it can pick it up with a special sensor or ideally with the camera most cars already have. This is really meant more as a proof of concept and construction of a prototype.
Thus I wanted to ask if somebody has ideas about what sensors and or camera modules I could take a look at.
I already have the raspberry pi cam in mind and I have some spare Logitech C920's and an Intel RealSense D435 around.
For the control of the led taillight I honestly just wanted to use an off the self demo-board and a decent MOSFET that can drive the thing.
sokoloff:
I would think that any optical link would likely be done via IR rather than visible light for compatibility with humans coupled with high enough intensity to be detectable in daylight.
97hilfel:
The point is to try it with the already installed on a vehicle. Transmission speed is not a primary conern.
tunk:
I would guess that at least some taillights use PWM and full intensity for brakes.
DaJMasta:
It could be tough to make universal - there's a big variety in tail lights used and driving mechanisms (not many relay drive ones left, but can you imagine the thrashing  :-DD ) .  Depending on bulb type, you could also run into switching issues if you were using particularly high intensity lights, different types will put in different limitations, so a "universal" drop in system could be pretty low performance compared to, for example, an all LED light car.


I think the bigger block could be the camera technology, actually.... because of framerate.  Unless you're going to PWM the lights to encode the data as effectively analog, your 60fps camera would struggle to get anything more than 30bps datarate.  If you could shrink the resolution to get more framerate you can probably do better, but you're still talking a few hundred frames per second, tops, so your datarate is still low enough that a unique identifier for the vehicle and overhead for a small ID packet being transmit could take multiple seconds.  There's also the issue that if your data is being transmit this slowly, it will manifest as flicker which could be distracting/unsafe on the road.  If you can get the frequency to a few hundred Hertz you can avoid it, but then your camera has to be specialized to be able to pick it up.

The typical optical data link is a set frequency pulse modulated with the data, basically the same idea as a radio link, and I don't think cameras will be able to manage that.  If you're going to try to develop a device to find such a signal, you need to make sure you can actually modulate your lights at the required speed, and you probably want to be looking at camera cores that offer 240x180 or lower resolution modes at a few hundred fps.
Navigation
Message Index
Next page
There was an error while thanking
Thanking...

Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod