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Sensor for vehicle presence

Former Member

Hello everyone,

 

I am trying to build a small personal project - we have a limited set of parking spots in the underground parking at work and it all works on a first come, first served basis. I am thinking of installing sensors for each parking place and build an app that can tell me how many available parking spaces there are.

 

I am trying to find out what would be the best sensor to use. The easiest way is to install the sensor above each parking spot and I was looking at the an ultrasonic ranger that works between 3 cm and 4 m. Do you think this would be the right sensor to use? What other options are there and what kind of sensors are usually being used in these cases?

 

Thanks,

Cristi Grigore

  • 0

    That seems to be a good way to do it.  They are making auto presence sensors to trigger green lights and are having a little bit of a hard time of it.  Putting a scale in the motorway was not always triggering for motorcycles.  Cameras have to deal with a variety of lighting circumstances.  I think an ultrasonic solution would be good enough for your circumstance, and fairly easy to implement.

  • 0

    Hi Cristi,

    I have seen a parking sensor system installed in the Oakland Mall of Guatemala City, Guatemala that senses the presence of a car in each parking spot and lights a red or green light above the car. It also marks the end of each parking row with an indicator to let the drivers know if there is a free spot in that particular lane. If you can id the manufacturer of this system they may give you some ideas on what type of sensors work the best. As I recollect the sensors were overhead.

    John

  • 0

    Hi, John, didn't know the Packers played in Guatemala.  Or, was that during your stint with the United Fruit Company?  Say no more.

    One can sense the presence of a car with a magnetometer.  One can detect it as a blackbody radiator.  One can use the car to interrupt an energetic beam, one could use ultrasonic range-finding.  It could be massed.  Heck, you could put an accelerometer in the tennis ball hung from a string. . .

     

    I heard that in the seventies a cop took to sensing the LO of car's FM stereos.  By reckoning in the 10.7 MHz superhet offset he could suss what station they were listening to.  All so he could pull over the cool kids.

  • 0 in reply to D_Hersey

    Hi Don, Yes it is pretty hard to miss a car with whatever sensor your want to use. I mentioned the system in Guatemala as she seemed to be more interested in results than experimenting and building her own especially on a multiple parking bay situation. It stuck in my mind as one doesn't expect high tech in a 3rd world country but there it was and more sophisticated than anything I had seen in the States. Your 70's cop sounds like he should have been fixing TVs instead of stopping kids. I was a cop in the seventies and I built small 12V to 6 and 9 volt regulators for all my fellow officers so they could plug their radios into the cig adapter. The city was too cheap to buy cars with AM/FM radios.

    Sorry Cristi, Don and I like to Jaw a little bit in other peoples threads from time to time.

    John

  • 0

    Perhaps you could save costs by using just one ultrasonic or optical proximity sensor on an overhead pulley that can take a pass down a whole row and map out the occupied parking spaces. If the line runs between rows, the sensor could map one side on the way down and the other side on the way back. It might have issues with latency if the row is long, but that is adjustable - for a price.

  • 0

    Thanks everyone for the helpful discussion. I found an ultrasonic sensor that I can easily purchase and is close to my house, so I will go with that.

     

    And John, I'm a "he", Cristi is the colloquial version of Cristian. I do know that native English speakers tend to identify Cristi as a girl though. And Romania is not really what I would call a 3rd world country, we're still part of the European Union image


    Cristi

  • 0 in reply to Former Member

    Hi Cristi, Thanks for explaining my incorrect gender assumption. You are correct, we have a different way for using the male and female nick names. I have a grandson named Christian and typically his nick name would be Chris. His mother who is named Christine would be called Christi. As far as the "third world" comment you misunderstood me. I was refering to Guatemala where I saw the awesome vehicle sensor. I had no idea that you were in Romania which I have never visited but sounds like a really nice place. Good luck on your vehicle sensor it should be a nice project.

    John