Hi! everyone i am building a project that involves measuring pressure on the road when a car stands over it. Now for testing i would be needing the same heavy duty sensor but some low level sensor which can provide the same functionality for say, hot wheels cars. I did some googling and came across the BMP sensor, which as far as my understanding tells me is just useless for measuring atmospheric pressure. I saw somewhere that maybe a pneumatic sensor would work best but i do not know which one would work with the arduino. So again, any sensor that the experienced people here can guide me regarding this?
thanks
P.S: you will have to dumb it down a bit for me as I do not know many technicalities. ;-;
To detect presence of a car use an induction loop. Pressue sensing in a roadway is far more difficult and
you have the problem that the wheel position would vary a lot.
Sensing a large piece of steel with an induction loop is trivial by comparison.
Get a force sensor (aka: a scale) and put it under the tyres. There are only four contact points for a typical car, that's four sensors. Measure the size of the contact surface of the tyre with the ground and the pressure is just a simple calculation away.
(@MarkT: OP mentions the car "stands over it" which makes me assume a stationery situation).
It’s not clear what you are doing here , do you just want know when a car is passing or do you want to weigh it ?
Pressure is force( weight) divided by area - that is very hard to measure .
If you just want to know it’s passing you can just use a rubber tube , sealed at one end and with a pressure switch at the other .
For weighing you need a suitable scale , using say a load cell and amplifier attached to a plate the call runs across .
hammy:
It’s not clear what you are doing here , do you just want know when a car is passing or do you want to weigh it ?
Pressure is force( weight) divided by area - that is very hard to measure .
If you just want to know it’s passing you can just use a rubber tube , sealed at one end and with a pressure switch at the other .
For weighing you need a suitable scale , using say a load cell and amplifier attached to a plate the call runs across .
Hi! I only need to check whether a car is passing or standing right on top of the sensor. I have no intention of measuring the weight.
wvmarle:
Get a force sensor (aka: a scale) and put it under the tyres. There are only four contact points for a typical car, that's four sensors. Measure the size of the contact surface of the tyre with the ground and the pressure is just a simple calculation away.
(@MarkT: OP mentions the car "stands over it" which makes me assume a stationery situation).
This seems like a reasonable approach, after googling force sensors, however these are a bit expensive and idk if the arduino will natively support them or not. Would there be any alternates? Furthermore, what if the car passes over, I think it will still detect a change.
Or look at the tube and pressure switch approach that you see sometimes fitted across roads to check traffic .
Car squashes tube and causes a pressure switch on the end to operate
Induction loops in the road surface work great for detection of those big hunks of metal, and are the preferred method for long term installations (such as with traffic lights).