Zone Crossing using Multiple triggers.

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Zone Crossing using Multiple triggers.

Post by MikeBwca »

I have two cameras that, from time-to-time, I use to count the number of vehicles & pedestrian traffic. This was mainly a Can-I-Do-It.

I used two zones A & B, a third zone G to connect them, and zone triggering A>B for one camera clone, and B<A for the other camera clone. Worked well, even when there were vehicles traveling in both directions at the same time.
But, there were a few issues.
- When objects passed each other, the foreground object would sometimes block or cause the background object to not trigger.
- Sometimes, for some reason-or-another, the zone-crossing would not trigger. Adjusting settings.. I just could not figure it out. I think it had to do with shadows, object color, lighting.

Here's what I came up with, and it works excellently. 99.5% successful.

I use 4 zones, and 3 cross-zone triggers. If the first doesn't get it, one of the other w will!
This could be applied horizontally, vertically, an angle, right/left-angle, or curve. Note that using 'Edge Vector' on anything other than a straight line of travel may result in a high number of no-triggers. This is explained on Page 85 of BI help.

Here is a sketch I made up doing this.
Zone-Crossing-Traffic 498.png
Zone-Crossing-Traffic 498.png (202.32 KiB) Viewed 958 times

- The first Zone in the direction of travel is wider then the rest to allow the motion sensors to fix (center-point of object), before the first zone-trigger.
- The separate zones are connected by Zone G. Note: The 'connected Zone' can be eliminated by overlapping each zone at least a few grids. But that makes placing the zones a little bit more difficult.
Both these points are explained at the bottom 2 paragraphs on page 83 of BI help.
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Re: Zone Crossing using Multiple triggers.

Post by YrbkMgr »

Very cool. I do a similar "fail safe" strategy too. Here's the layout of my tripwires - click for larger view
Simple Zone Crossing Example
Hotspot Trigger + DeepStack Example

Questions, comments, criticisms, all input welcomed...
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Re: Zone Crossing using Multiple triggers.

Post by CDAHome »

I would love to be able to have a zone crossing setup like yours. Even a simple one that works would make my day. I have been using BI for many years with great success on this pretty robust system. Everything is up to date. I am not presently using AI but I have successfully used just about every feature offered with the exception of one; I have never been able to get a simple AB or A>B Motion Crossing to trigger a recording.

I have my over all 'A mask' (as you have in your image) and then added my 'B' & 'C' masks using the BC or B>C command in the Object Detection window (I've tried it both ways). This is on my driveway so my goal was to have an automobile approach and span 'B' while then entering 'C' which in my mind should trigger the alert and record, but it does not. It triggers the little 'motion' alert icon but not the one for 'record'.

I can trigger a recording if I have just one simple zone on the driveway but I need a 2-zone crossing setup to minimize triggers from deer and the occasional moose. Yup! My idea was this: If I have an overall zone 'A' and then 2 more zones (B&C), and they are spaced approximately 10 ft. apart, a car should be able to cover most of the B&C zones simultaneously and trigger the recording, whereas a deer would not be large enough to span both zones and would not cause an trigger. I also have tried this with the zones almost touching and also with them overlapped. I have my 'Object Crosses Zones' checked and have tried with 'Object Travels'" checked and unchecked, same with 'Black & White' and 'Method: Simple', etc. I have rebooted and redrawn my zones. Deleted the camera a started over, etc. Still no good. Can anyone suggest anything that I may be missing here? Sorry this got so long.
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Re: Zone Crossing using Multiple triggers.

Post by Pogo »

Could you post a screen shot of your driveway?
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