i m looking to detect when a bicycle cross the lap/finish line to count the laps and chrono. It is for bicycle or runner so it is difficult to use light signal (LED). I can use Bluetooth low energy but not very accurate. I think about a electromagnetic loop on the ground or something like this and the bicycle will have arduino with Hall effect detector.
But do you think we can detect something with Hall effect around 1M - 1M50 above the loop.
The idea is that it will trigger the arduino to send the id of the runner to ground/counter station.
Not what you want to hear, but this works: take a RPi+camera+openCV, that's basicly the same setup used in "professional" systems. When your fialists come in hundreds at a second .. well .. maybe your contest is missing some essential part
There are other solutions. Some 25 years ago I joined a race (one of the very few I ever joined) and there we got a vest with some kind of transponder in it. At the start and finish you run through a gate, where the transponder is read. The gate could only read it when the transponder is inside, or very close to inside; we got times with second precision, not more than that. Good enough for that race. Must have been some kind of RFID tagging. Such gates won't work too well for bicycle races, as they're quite narrow for a bike at high speed. Nor do they work well for mass arrivals.
So... hereby some essential questions you must quantify before you can start designing a solution.
At what speed do the bicycles arrive?
How many cyclists or runners may arrive per second?
All in one lane or spread out?
What is your required time resolution?
What is your required spatial resolution (i.e. how far before/after the finish line is it OK to record the arrival)?
What, if anything, could be attached to the runner/cyclist to aid in identification?
Can you build anything into the track?
Does the solution have to be mobile?
What is the width of the finish line?
i m looking to detect when a bicycle cross the lap/finish line to count the laps and chrono. It is for bicycle or runner so it is difficult to use light signal (LED).
A beam-break system sounds like the ideal method - why do you discount it?
Rubber tube across the road with one end plugged . Pressure switch on the other end .
When the bike passes it squashes the tube, increases the pressure and the switch operates .
MarkT:
A beam-break system sounds like the ideal method - why do you discount it?
Hi,
Because if 2 runners cross the line in same time you cannot identify who pass the line. It is why i m looking to send a signal to the runner and it will trigger to answer with the id.
