Hi
I am planning to construct a device that can count amount of vehicles passing by. The problem is that I want to count in multi-lane road whereas the device must be able to distinguish which lane the vehicle pass. I did some research like using road tubes, proximity sensor, infrared etc but all of them only works for single lane.
Any ideas?
Thank you so much
Is this something you want to work on one particular section of road, or do you want to be able to use it in different places?
How were you planning on getting access to the road to put down things like road tubes without getting killed?
I am struggling to come up with a way this can be done. The only solution I can think of is a camera mounted high and then image processing - but that is beyond an Arduino.
This normally done using induction loops in the road surface for long term (one loop per lane), or a pressure sensitive wire across the road on top of the surface for short term installations (should be quite easily adaptable to distinguish lanes).
This works best for cars and other big chunky metal ones; may not work for bicycles or motorbikes or other small vehicles. Induction loops are prone to not detecting bicycles.
ardly:
How were you planning on getting access to the road to put down things like road tubes without getting killed?
Close the road during installation.
(OP didn't mention which kind of road and for what purpose and what his job is so I'm making all the convenient assumptions).
Overhead mounted laser distance sensor?
HellenT:
but all of them only works for single lane.
So what is the problem? If you have a 5-lane road, buy 5 of them.
I'd try the laser distance sensor on the side of the road - measure the distance to the side of the car to find what lane it's in.
MorganS:
I'd try the laser distance sensor on the side of the road - measure the distance to the side of the car to find what lane it's in.
Won't work reliably with a 5-lane road due to very likely overlapping - you may partly be able to filter that out but not reliably (a truck can hide several cars from view).
For a two lane road - get two surface tube type counters - put one sensor in just one lane - put the second sensor across two lanes - subtract the one lane count from the two lane counter to get the count for only the second lane - done all the time
but I do see two tubes for each lane mounted much of the time - I am guessing the counters are used to check each other
saildude:
For a two lane road - get two surface tube type counters - put one sensor in just one lane - put the second sensor across two lanes - subtract the one lane count from the two lane counter to get the count for only the second lane - done all the timebut I do see two tubes for each lane mounted much of the time - I am guessing the counters are used to check each other
two tubes are for speed.
I have seen a black box, about 1/2 inch tall and 10" x 10" that was taped to the road (tar tape) in the center of the lane.
inductive counter, one per lane.
takes about one minute to install
then they just cut the tape and leave the remnants.
Go search and read about TIRTL
An extremely cool technology for this type of application, but the tech involved is way beyond the price-performance of an Arduino solution.
dave-in-nj:
two tubes are for speed.
I have seen a black box, about 1/2 inch tall and 10" x 10" that was taped to the road (tar tape) in the center of the lane.
inductive counter, one per lane.
takes about one minute to install
then they just cut the tape and leave the remnants.
Multiple tubes for redundancy, not speed. Think of that truck/trailer with 10+ axles with wheels about 8 inches between tires.
Paul
here is a site with the glue down box to which I spoke.
http://www.terraengineering.com/idot-traffic-counts/
Paul_KD7HB:
Multiple tubes for redundancy, not speed. Think of that truck/trailer with 10+ axles with wheels about 8 inches between tires.Paul
Multiple tubes can do both speed as well as vehicle count and vehicle class.
you are correct that a vehicle at 60 MPH with a wheel base of X will trigger the leading tube at a certain delay. a 3 axel with have that first delay, then two rapid ones. a long vehicle will have a long delay, then the rapid ones.
I would expect that by timing and noting the duration between pulses, one could classify quite a bit. the duration between the tube sets the vehicle speed, the time between the first tube's first pulse and subsequent pulses would classify wheelbase.
"Road tubes are used to detect vehicle axles by sensing air pluses that are created by each axle (tire) strike of the tube in the roadway. This air pulse is sensed by the unit and is recorded or processed to create volume, speed, or axle classification data. While one road tube is used to collect volume, two road tubes can be used to collect speed and class data."
The tubes I see are placed much closer together than any two wheels could possibly be, so can easily detect speed and direction of every single wheel passing. The only problem may be the two ends of the axle not passing at the same time.