Detector that counts and alerts

[JustinAD]

Hi all

I need to upgrade our complex's security system by installing a IR beam that alerts our camera monitoring company if more than one body crosses it while the gate is open. A thief entered and stole, the other day, because he managed to sneak in while a delivery person rode out (resident opened via an app and the gate is out of sight). Using the remote should reset the programme as when the gate is closed so that one can stop a closing gate and open it in order to enter or exit. The security company only watches the gates at night (too busy during the day).

I know retailers have people counting tech, so can that be integrated?

 

[IRstuff]

It's hypothetically doable. Are you thinking of DIYing it? However, the sensor is not the issue, it's the false alarms.

Say two legitimate entities arrive and the second piggy-backs the first's entry, as in your example, but the second person was legitimately supposed to enter. There's no sensor or coding that can tell from a single beam breakage or even fuzzy image as your attached, to determine whether the 2nd entry was legitimate or not.

I used to live in a large apartment complex, and during the day, it would not be unusual for 2 or 3 or even 4 cars to arrive simultaneously, and all would enter from the first car's remote activation.

It may be possible to make use of the remotes themselves and add something like an RFID or NFC tag and correlation those with crossing the detector. It looks like only ultrahigh frequency RFID tags would provide sufficient range

https://www.impinj.com/products/tec...le there is some variance,rate than LF or HF.

https://www.atlasrfidstore.com/impinj-intelligence-tags/

. Nevertheless, someone would still need to correlate each beam crossing or detected object in the surveillance camera with each RFID tag passing the threshold. You probably need to consult with a security company or do a much more thorough internet search, as I did, to see if something like that already exists. While RAIN RFID supposedly has a maximum range of 12 m, if it's inside someone's car, that range likely drops significantly, so the reader will probably need to be as close as possible, say, within 3 meters.

Nevertheless, you might still have unacceptably high false alarms, say with 2 or 3 simultaneously arrived deliveries that wind up piggy-backing the entry. Our local police allow for 1 false alarm per year before they start fining(charging) for them.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

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[JustinAD]

@IRstuff, Thank you for your reply. I am not concerned about the likely false alarms because most of the residents here stop and wait for the gate to close behind them to prevent tailgating. The ones not obeying the rules will be responsible for the false alarms but these will be minimal and perhaps they will be fined a nominal amount. The camera monitoring company will review the footage every time there are multiple interruptions of the beam and send an image to our security Whatsapp group or send a patrol if they suspect an actual intruder has entered.

I came across a patent with a similar idea (

https://patents.google.com/patent/WO2008020893A1/en)

but I have nothing more. I really need someone to advise me on how to design this, including code. What are all the necessary components?

 

[IRstuff]

What are all the necessary components?

Depends on what you are changing out.

> Something to detect entities crossing the threshold, so infrared is possible, but sunlight is a major problem. Radar-based motion sensor is a possibility. Most security cameras these days come with some amount of motion detection, but YMMV. Ultrasonic beam is possible, but they're FAT, so depends on how far apart transmitter/receiver are placed. Detection data needs to be time tagged. Installation and tamper protection

> RAIN RFID box, with a slew of compatible RFID tags, including extras for lost tags. Detection data needs to time tagged. Installation and tamper protection. Since each tag is unique, they can be specifically tied to individual users, and lost remotes/tags can be flagged.

> Computer to collect time tagged data and correlate. Software to process and detect threshold crossings without accompanying RFID detection, as well as usage of previously lost remotes/tags. Privacy policy needs to be in place for recordkeeping of residents' entries; retention/disposal of data.


You could possibly forego the RFID tags, but everything else would still be needed.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

faq731-376 forum1529 Entire Forum list

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[waross]

Put a second IR beam, "A" ahead of the main beam "B". Allow "A"-"B" crossing and allow "B"-"A" crossing.
Alarm on "A"-"B"-"A" and "B"-"A"-"B" crossing.

--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[SwinnyGG]

You need to hire a security company to do this for you. If you're here asking what you need, you don't have the skills to do this yourself.

 

[JustinAD]

Terrific ideas and advice here!!! Thanks so much.

 

[Gr8blu]

Possibly least cost-effective (but still VERY effective) way to solve this is to put a second gate in, physically located such that only one vehicle (or person) can be between the two. First one triggers (open), second remains closed. First one triggers (close), then second opens (after a short delay). Second triggers (close). Logic to do the triggers needs to be applied for both directions of travel - as well as a means of prioritizing whether the IN or OUT traffic takes precedence.

This is how the interlocks on watertight compartments and airlocks work, for example.

Converting energy to motion for more than half a century