How to calculate the length of the board that goes through the saw?

Question

Arduino

It is necessary to establish accounting of the forest at the sawmill.
One of the tasks is to get information about how much wood and how long was passed through the machine.
The machine calibrates the board, processing it from 4 sides. Boards come in different lengths, you need to find out how many boards were and how long.
Are there ready made solutions for this? Can this be done with arduino?
The thought moves towards some kind of laser/optical sensor, which can calculate its length by moving the board past the laser beam.

Answer 1

_______1-------------------------------------------2 <<<<
_______3 ------------------------------------------------------4 << <<<<<<<<<
^5__________________________________________________________
As I understand the processing speed is constant, so the time 1-2 and 3-4 will be proportional.
As for the sensors, you can collective farm, or you can take sensors from industrial automation, there are ttl levels. The truth is refreshingly expensive

Answer 2

The device of the machine is not very clear (I have not seen such live)
But the thought immediately came to my mind that it is possible that the machine has some kind of feedback sensors that implement protection? Maybe it's easier to connect to them?
If not, then with a laser it looks like a good idea, but if you duplicate them several times + probably sawdust and any garbage can ruin everything (you will need to take care of self-cleaning). I will add to the answerer from above - there is room for a large error in the place where the board is fed, since the engines can rarely work with a very constant number of revolutions, and therefore a very large error can accumulate. I would also add a connection to the engine and read its revolutions, thus getting the speed of the board.

Answer 3

Search among ready-made solutions for input material?
https://www.yandex.ru/search/?text=%D0%B0%D0%B2%D1...

Answer 4

Thanks for the replies, but the issue is still open.
Unfortunately, I didn't find any solutions. This is not accounting for round timber, this is different.
The wood already comes sawn in boards on pallets, wood of different sizes - standard sizes 0.45, 0.65, 0.75, 0.95 - on pallets one size and length > 1 meter, everything is on the pallet.
Here, you need to calculate the length. And if this is understandable with standard lengths, then the length gauge must be measured for each board separately. And I thought maybe there is some solution .. I know that ordinary optical mice can measure the distance of the "run". And I thought, all of a sudden, they came up with the same thing to measure the length of the board .. so that there was some kind of optical sensor that reads the movement of the board and this determines its length.
But it is, my fantasies

Answer 5

https://aliexpress.ru/popular/measuring-wheel-enco...
Industrial Encoder Wheel Meter Measuring Wheel Encoder Special Support For Rotary Encoder Scroll/Rolling wheel Counter
There are solutions. In the form of a measuring wheel. Optical I think only if with periodic
blowing with compressed air. Google in English, or write in hp help.

Answer 6

In the form of a measuring wheel.

Agree with Tohacrat .
The best solution, in my opinion. Can be embodied from g ... and sticks (improvised materials). Wheel + optical encoder = curvimeter with data output to Arduino, Raspberry, ESP, etc.