Proximity Sensor/Transmitter
Proximity Sensor/Transmitter
(OP)
Does anyone know if the following device exists?
1) Will sense the presence of a item, such as a car.
2) Will then transmit this information wirelessly to a receiver up to 1/2 mile away.
3) Be self powered.
If yes then where can I find one?
1) Will sense the presence of a item, such as a car.
2) Will then transmit this information wirelessly to a receiver up to 1/2 mile away.
3) Be self powered.
If yes then where can I find one?





RE: Proximity Sensor/Transmitter
There are dozens of them. Up to miles!
Keith Cress
kcress - http://www.flaminsystems.com
RE: Proximity Sensor/Transmitter
Rich.....
Richard Nornhold, PE
http://www.ovenind.com
RE: Proximity Sensor/Transmitter
Another question is whether by "proximity" you mean actual distance, or simply existence of the item within a certain boundary. A corollary question is whether the presence of the item outside of some boundary is allowed to be detectable.
TTFN
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RE: Proximity Sensor/Transmitter
What we are actually trying to do is manipulate traffic flow on our property in real time, both day and night.
The thought is to sense the presence of vehicles as they come close to what are effectively traffic lights. We would like to count the number of vehicles approaching the intersection from all four directions and relay this information in real time to a processor. The processor then decides which traffic flow is most important, based on criteria set by engineering.
We were thinking of sensing oncoming traffic from about a mile away, and hopefully be abale to determine if the vehicle is moving or is stationary. (ie if stationary then it means there are many vehicles travelling in that direction). There will probably be multiple sensors with their density increasing as you get closer to the intersection, constantly generating data that can be processed.
Ideally we would like to drop a sensor into the road and have that sensor transmit its' data to a processor. It would have to be inside a weatherproof box and be easily accessable to change the battery.
Does any specific device or manufacturer come to mind?
Tahnk you
RE: Proximity Sensor/Transmitter
One Vendor: http://
Gov Handbook: http://www.tfhrc.gov/its/pubs/06139/chapt5b.htm
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This is normally the space where people post something insightful.
RE: Proximity Sensor/Transmitter
Inductive loops are probably the norm, but their replacement frequency is on the order of a few years, since the pavement is compromised to put the loops in place.
You might also consider conventional sensors, which I've seen on the approaches to weigh stations.
http://www.wavetrix.com/about2e.html
http://smarteksys.com/?src=overture
http:
http://www.meas-spec.com/traffic-sensors.aspx
If you do a search for "traffic sensor," you'll see that the choices are quite plentiful.
TTFN
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RE: Proximity Sensor/Transmitter
This is so when the loops break due to pavement movement someone can come out and try one of the other loops and hopefully find one that is still intact. That also incurs expensive service calls.
What is now favored is video cameras that only sense motion, they don't actually care about vision. They are mounted on top of the street lights, and signal light beams, and pointed at the area of interest.
Keith Cress
kcress - http://www.flaminsystems.com
RE: Proximity Sensor/Transmitter
TTFN
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RE: Proximity Sensor/Transmitter
Because of the issues raised here we were hoping that some manufacturer out there has adopted sensor technology from industrial applications to use in traffic.
I'll keep looking at industrial equipment that may be adapted since it seems that there have been significant advancements in these areas of control systems.
Walt
RE: Proximity Sensor/Transmitter
For example they make a sensor / scanner called an LMS that can be used to pinpoint the location of an object within it's field of vision and provide information on the movement or progression of that object in the field. We have them being used right now on sports fields to track player positions and in racing to track vehicles. Ever watch a race and see the little icons that follow the car with the driver info and wonder how they do that? That is how.
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