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Thread: Faster / more accurate presence detection

  1. #1
    Automated Home Legend Paul_B's Avatar
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    Question Faster / more accurate presence detection

    Evening all,

    Two areas exist in my home-automation that I feel need further improvement:
    1. Presence detection on stairs
    2. Presence in small rooms (ensuite / WC)

    In both cases the standard PIR setup for presence can be slow or miss presence altogether. The problem with stairs is that I have a sizeable dog so have to use pet tolerant PIR which are slower to detect due to masking. My home has a fairly small hallway and landing so it is possible to walk between rooms and not be detected. The other problem is with small rooms, mainly the WC and ensuite where the delay in PIR detection after a door is closed means that again presence detection can be an issue. Some of this down to my aggressive timeouts but even at 10 seconds for the ensuite I get questioned by SWBO as to whether the light will go out.

    Now I have a IR proximity sensor working (thanks Karam) I was thinking if I could use a single one to improve detection on shutting the door and breaking the beam before the 5 second threshold for the PIR causing a locked presence state? Failing that could I combine two IR sensors a small distance apart into a logical direction object; which again I hope might overcome the problems I have described?

    Paul
    Last edited by Paul_B; 22nd June 2015 at 09:09 PM.

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    Automated Home Legend chris_j_hunter's Avatar
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    some thoughts ...

    very interested in the stairs detection approach - we have PIR sensors covering each landing, top & bottom of stairs and, at least in our case, the issue is distinguishing between people using the stairs & people using the landings to go between rooms without using the stairs - for this, the beam-sensor approach might provide a solution !

    the small-rooms issue seems more tricky - we use aggressive timeouts, too, and find we have two problems, one when people are too still for too long, and the other when they move into a blind spot ...

    to help with the first, increasing the timeouts is the obvious answer, 'though that might mean the Light staying on longer after people leave the Room - OTOH, in some cases, we have reed switches on our doors, so that shouldn't happen, thanks to Cortex logic meaning they would go out when the door is closed ...

    to help with the second, we make us of other indicators of people being around - in our case, that means button presses & relays switching water outlet solenoids (all bar one of our water outlets being automatic / controlled by Cortex) ...

    in Rooms in which we have these problems, we've sometimes implemented (we call them) Beacons to maintain presence when people move into blind spots - Beacons meaning NOT-gate / Virtual Relay pairs generating pulses that are fed to the Room's Motion detection connection, with the Beacon activated by some suitable mechanism, logical (eg: combination of circumstances) and/or physical (eg: Button-push), and the pulse frequency being kept as low as possible (pulses need only anticipate the relevant time-out) ...
    Last edited by chris_j_hunter; 28th June 2015 at 09:28 PM.

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    Automated Home Legend Paul_B's Avatar
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    Chris,

    I have reed switches on my doors as well but the period of non-detection of the PIRS in Cortex to avoid false positives means that someone can have finished moving before the PIR become active again. I was wondering if I could just register the IR sensor as a button rather than a proximity or distant sensor as button activation would infer presence at least in the same rooms. Still interested if a pair of sensors could be used as direction indicators for the stairs. At total cost of 48 for four sensors would be a pretty cheap solution for this problem, but would be interested in Karam or Viv's view

    Paul

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    Automated Home Legend Karam's Avatar
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    You can adjust the PIR inhibit period from the room behaviour advanced option menu, but I'm not entirely convinced that there may not be another issue so I'm awaiting to discuss with Vivian.

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    Automated Home Legend Paul_B's Avatar
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    Karam,

    Happy to wait. Chris has given me some ideas of improving my existing setup which I'll experiment with over the coming days.

    I'd be interested if you / Viv would recommend a couple of the digital versions of the Sharp IR with a ODI-002 setup as direction detector for the top and bottom of the stairs?

    Paul

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    Automated Home Legend chris_j_hunter's Avatar
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    another trick we use, Karam having pointed out that a virtual ODO can be rigged as a counter, is to use one to help switch Lights on as a function of the level of activity ...

    the new Accumulator object gives more options for this sort of thing, too ...

    Chris

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    Automated Home Ninja Viv's Avatar
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    Quote Originally Posted by chris_j_hunter View Post

    the new Accumulator object gives more options for this sort of thing, too ...

    Chris
    The new accumulator object is not on general release and will be available in Cortex 27

    Viv

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    Automated Home Legend Karam's Avatar
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    Quote Originally Posted by Paul_B View Post
    Karam,

    Happy to wait. Chris has given me some ideas of improving my existing setup which I'll experiment with over the coming days.

    I'd be interested if you / Viv would recommend a couple of the digital versions of the Sharp IR with a ODI-002 setup as direction detector for the top and bottom of the stairs?

    Paul
    I believe it was a GP2D15 that was used in the original testing and Vivian made some modification to a resistor at the back to increase range from the spec. value of 24cm to ~130cm. I can't find the GP2d15 at usual sources however RS seem to have something with similar part number and spec (315-422) and another variant with 90cm range (315-466). Probably there are some resistors in these which can also be 'played with'.

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    Automated Home Legend Paul_B's Avatar
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    Hi All,

    Got around to swapping out the original test analogue Sharp IR sensor for a new device that is digital and also detects over a greater distance, it is a Sharp 2Y0D02 F 33 which I think I got from RS and is like http://uk.rs-online.com/web/p/reflec...nsors/0315466/ [315-466] Glad to report it just works when connected to a digital input connection, so long as you use a transformer to step down from Idranet 12v to 5.5v (I bought this one on Amazon - http://www.amazon.co.uk/dp/B008VORAD...986871_TE_item).

    Detection seems good but I'm using as a beam break rather than measuring the distance and on stairs. Beam is nice and narrow so positioned just under the bannisters it detects us humans but not our large Golden Retriever. Intention now is to add a second either on the next step or next step but one and link to a logical distance sensor. Need to speak with Viv as it would appear distance can only be linked to doors rather than stairs

    Hope this might help others.

    Paul

  10. #10
    Automated Home Legend chris_j_hunter's Avatar
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    good to hear - gives a way forward ... how about neatness of installation - now you're sure it works, how will you achieve a neat install ?

    we made our own design for our bannisters, and we included boxes at one end, as part of the design, which hopefully gives us some freedom on installation, 'though best laid plans & all that !

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