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I need to sense the arrival of vehicles along a driveway, to switch on security lighting at night. But only to operate when vehicles arrive, not when they are leaving and driving away.

I bought a USVD-4X ultrasonic detector:
Vehicle Detector | Drive Through Sensing - https://www.motion29.com/products/controlandsensing/drivethruvehiclesensorusvd4x/default.htm
I assumed the 'pulse on entry' and 'pulse on exit' settings determined the direction of travel of the vehicle (ie entry to, or exit from, a premises). But tests show otherwise: it means pulse on arrival and stopping by the sensor, and/or another pulse on driving away, like at a drive-through food place.

Is there any off-the-shelf device which will do what I need, without having say two PIRs or break-beams, then complicated logic in a microcontroller which will probably need rebooting or will otherwise go wrong. I want a fit-and forget industrial quality solution.

Any ideas?

Thanks, Mark
 

marconi

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One way to remotely detect both movement and direction is to use an active radar system with moving target indication signal processing. I found this microwave product which is easily programmable and can sense presence, movement and direction.

In its description it says:

The Herkules is supplied with default settings for a variety of industrial door applications, broad selection of evaluation options for people and vehicles with optional direction recognition and crossing traffic masking.

You might want to study it further and contact the manufacturer.

Microwave Motion Detector | Vehicle Detector - https://www.motion29.com/products/controlandsensing/microwavemotiondetectors/default.htm

Would you provide us with an update on your final solution please?
 
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B

Bobster

You don't want a micro controller but something like a Rockwell 810 or siemens logo with 2 photoelectric sensors would be simple, reliable and reasonable cheap.

It wouldn't take any more than 4 lines of code.
 

Charlie_

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The best and easiest solution for this problem would be a vehicle radar detector, using the Doppler effect
I have fitted hundreds of these devices to many traffic signal systems..
The best one out there in my opinion is the Siemens Heimdall..
Very easy to install and to set up, very robust and reliability is 2nd to none.
No need to write any code, the units have little dip switches for various parameters.
 
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DPG

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Does it really matter that the security light comes on when cars drive away? A bit of illumination would have been better if anything I would have thought.
 

Spoon

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Does it really matter that the security light comes on when cars drive away? A bit of illumination would have been better if anything I would have thought.
Most prob a fussy customer who is happy to pay 4 times the amount to get things done as he/she wants.
 
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Does it really matter that the security light comes on when cars drive away? A bit of illumination would have been better if anything I would have thought.
A perfectly good point but yes, as it's wasteful and feels poorly engineered, as the sensor will be at the end of a 200m drive, so the 'bit of light' (actually about 20 LED floodlights around the site) is way behind you. There are a few normal PIR fittings to help with leaving.

Most prob a fussy customer who is happy to pay 4 times the amount to get things done as he/she wants.
Absolutely! The customer is a nightmare who over-engineers everything just for the fun of it.

ps. This is my own house:)
 
S

Squid

Tell you customer to work harder and to buy a house with a larger drive, one gate entry the other exit, simples......... ;o))))
 
Most prob a fussy customer who is happy to pay 4 times the amount to get things done as he/she wants.
Then moan because "customers" sus out they can get carpark lit for their mates by driving out -Then "Reversing" --irresponsibly-- !
-- Any cyclists are likely to be flattened--
(and doubly peed-off)
 
Hit button on wall -before leaving - Timer blacks out PIR for pre-detemined time( /or/shines discreet batman spot at day sensor of PIR ? .)
(leaving in stealth -very batman)
-Night vision building nicely-
 
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The Herkules unit mentioned earlier will do what you require, you just have to make sure you mount it on a firm surface and at least 3 meters from the ground. If you get in touch with us (Motion29) on Tuesday, we'll arrange an exchange of the USVD-4X with a Herkules.
 
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  • #13
The Herkules unit mentioned earlier will do what you require, you just have to make sure you mount it on a firm surface and at least 3 meters from the ground. If you get in touch with us (Motion29) on Tuesday, we'll arrange an exchange of the USVD-4X with a Herkules.
Hi Andy
To find me on here you're either an expert stalker, or you have some very effective Google alerts going on! :)
Thanks for the offer to exchange. I'll get the old unit sent back asap.
It might be a good idea to amend the description from 'entry ' and 'exit' to perhaps 'arrival' and 'departure', so this doesn't happen again.
Many thanks for your exemplary customer service - If anyone else on here needs vehicle detection kit, you know where to go!
 
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  • #14
... Would you provide us with an update on your final solution please?
Certainly. I'll post a photo once it's done and actually working ...

Many thanks to you and Charlie for recommending Doppler radar. I should have thought of that myself!

cf. 'If this [red] sticker is blue, you're driving too fast' :)
 
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Hi Andy
To find me on here you're either an expert stalker, or you have some very effective Google alerts going on! :)
Thanks for the offer to exchange. I'll get the old unit sent back asap.
It might be a good idea to amend the description from 'entry ' and 'exit' to perhaps 'arrival' and 'departure', so this doesn't happen again.
Many thanks for your exemplary customer service - If anyone else on here needs vehicle detection kit, you know where to go!
Hi Mark,

No stalking going, just coincidence that the link you originally posted was used yesterday when I was covering our Web chat service. Happy to get you the correct solution working for your project.
 
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Herkules unit ... have to make sure you mount it on a firm surface and at least 3 meters from the ground. ...
One concern: this is on the drive to a listed building where ugly poles aren't really appropriate. Is it acceptable to mount the Herkules 600mm up from the ground on a granite post and it still work? Can be angled upwards if needed.

There is one existing power post I could use, but this has 3 x 12kV cables on one side which supply the whole village, and so have continuous current in them; I suspect mounting the unit next to these might be inadvisable due to the EM field?
 

marconi

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One to check with the manufacturer - but I don't think EM interference from the power lines will be a problem though I would recommend you experiment first with position, height, elevation angle and direction of 'look' by the antenna relative to the driveway to confirm reliable performance to bowl out not only EM interference but nuisance detection caused by reflections from 'clutter' in the field of view. With regards to clutter think about objects that will be moved by the wind. Rain and snow might also set it off. This is the nature of MTI/doppler active radar detection - good clutter rejection (of moving grass say) is an important performance parameter alongside reliable target detection ( of the car). It is a difficult problem if the clutter spectrum and target signal spectrum overlap. You have got me reminiscing about a previous life.

Moving target indication - Wikipedia - https://en.wikipedia.org/wiki/Moving_target_indication
 
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... This is the nature of MTI/doppler active radar detection - good clutter rejection (of moving grass say) is an important performance parameter alongside reliable target detection ( of the car). ...
Hi Marconi: Fascinating stuff, thanks for the post.

The device will be looking straight down the drive, mounted on one side (using the utility post if I can get away with it). There will indeed be long grass and crops on one side during the summer. The other side is a hedge which doesn't blow about much.

False radar signals might be a nuisance, but no one will end up being engaged by 30mm cannon fire :). I'll do some trials anyway.

From your name, not one of us are you?
Caister Marconi radio station contacts more than 160 amateurs in 36 countries | Southgate Amateur Radio News - http://www.southgatearc.org/news/2019/april/caister-marconi-radio-station-contacts-more-than-160-amateurs-in-36-countries.htm#.XM9EiRRKhaQ
73 de M0UMG/M0MUI/M0XUI (geeky family) :)
 

telectrix

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2.00 a.m.... cordless angle grinder, speed camera. modify triggering.:eek::eek::eek:
 
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Job done!

As suggested, I fitted a Bircher 'Herkules' Doppler radar unit. It works brilliantly: solid discrimination between vehicles and people, with equally solid direction indication.

Not wanting to add to clutter, I fitted it on an existing utility pole at 3m up, on a small bracket to keep it away from the HV cables.

DSC_0480.JPG

DSC_0484.JPG

All parameters are settable in software. This device will do pretty well whatever you want it to, and is massively more reliable than PIRs.

As the Herkules' two volt-free relays give only a pulsed output on activation, it was necessary to fit a delay timer downstream in the home automation control panel, so it now acts like a standard PIR, with a selectable lights-on time after each activation.

DSC_0488.JPG

I used a Radiospares Part No. 896-6813 Multi-function timer, which is very versatile, multi-voltage, and at £23 good value compared to branded alternatives.

DSC_0490.JPG

So that the lights come on only after dark, the supply side of the multi-timer relay is fed by 24V from a dusk-to-dawn unit elsewhere in the installation.

The whole thing feeds into my lighting, heating and irrigation control panel in the kitchen.

DSC_0487.JPG

This is a matrix: columns are inputs (Permanent-on, Timers, PIRs etc), rows are various garden lighting circuits. Any input may be assigned to any one or more outputs. There are no electronics, no touch-screens, nothing to go wrong for years! :)

DSC_0486.JPG

Like I said before, it's not at all over-engineered. :)
 
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DPG

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That's completely over the top and unnecessary. What's the point?

But...... I love it!! That professionally made stainless panel is a work of art.

I approve!

Don't leave all your keys out in the open though - easy for thieves.
 
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That's completely over the top and unnecessary. What's the point?
But...... I love it!! That professionally made stainless panel is a work of art.
I approve! ...
Ha Ha! Thank you for the kind comments :)

If anyone needs a custom control panel I recommend the suppliers I used: The Premier Engraving and Sign Co.

All you need is to draw the panel in any graphics app (I use an ancient version of CorelDraw), export to-scale as a .pdf or .eps then they do the rest, including telling you if anything doesn't quite work.
Nice , I like it!
Is the front plate connected to earth ;)
That's not stainless steel, it's 'matt silver Traffolyte' in 3mm. So non-conductive on the back :)

And here, for your delectation and enjoyment, is another panel they made for me, this time for a Unimog camper I built last year.

Panel(small).JPG

Panel2(small).JPG
 
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