RE: Room occupancy detection and door opening/closing - 1-wire or wireless solution?

[Marcus Warrington <marcus.warrington@xxxxxxxxxx>]

Paul,

> as my lounge sofas don't have removable cushion pads that I could put
anything under

In that case you could try using a pulsor http://www.sureaction.com/pulsor.htm
glued to the underside of the Sofa frame. They are very sensitive and I'm
sure they'd detect someone sitting down. The disadvantage is that unlike
the pressure sensor they only detect the change not the constant presence
i.e. the would detect as someone sat down or stood up but not while they
where sitting down.

> - I like the sound of the "curtain" ones you mentioned,
>- is this a specificmodel/type or PIR designed for this use?

Yes, their designed to monitor entrance rather than the full room itself,
much like breakbeams but without needing a device on either side.

Have a look at ;http://www.pyronix.com/php/web/productDisplay.php?im4=P%20I%20R&id=96&id2=187&conf3=KX18DC&cat=KX%20Series
If you click the "full technical Specification" link on that page
you'll see the actual zone coverage.
This ones still designed to be mounted to the side of the entrance wall,
but you can get others that point directly downwards.

Marcus

________________________________
From: ukha_d@xxxxxxx [mailto:ukha_d@xxxxxxx] On Behalf Of Paul
Gordon
Sent: 15 October 2008 16:26
To: UKHA Group
Subject: RE: [ukha_d] Room occupancy detection and door opening/closing -
1-wire or wireless solution?


Some good suggestions there...

I've thought about the pressure sensors under the seat cushion idea in
the past, - it works well enough in my car... never got round to trying
anything though, as my lounge sofas don't have removable cushion pads
that I could put anything under, so don't lend themselves to this kind
of modification.

I guess using *multiple* PIR's could also help quite a bit, - especially
if carefully positioned with a narrow field of view etc. - I like the
sound of the "curtain" ones you mentioned, - is this a specific
model/type or PIR designed for this use?

Paul G.

> -----Original Message-----
> From: ukha_d@xxxxxxx<mailto:ukha_d%40yahoogroups.com>
[mailto:ukha_d@xxxxxxx<mailto:ukha_d%40yahoogroups.com>]
On Behalf
Of
> Marcus Warrington
> Sent: 15 October 2008 11:50
> To: UKHA Group
> Subject: RE: [ukha_d] Room occupancy detection and door
opening/closing -
> 1-wire or wireless solution?
>
> >> but it can't tell you in what direction they're going, so
> >> how will you know whether to count someone out or count
someone in?
>
> You could get an idea of direction if combined with the PIR data i.e
>
> If door state changed from closed to open AND the PIR was triggered
within
> the Room then you could assume someone was leaving the room. If on the
> other hand the Room PIR detected nothing but the hallway PIR had been
> triggered then assume they are entering the room.
> Of course the accuracy degrades when you have more than one person in
the
> house..
>
> >Beam-break sensors in the door jamb would signal someone actually
> >passing through the door rather than just opening it. Multiple
> >beam-breaks positioned horizontally could even give you the
direction
of
> >travel
>
> Rather than beam-break sensors (which might be hard to fit i.e. having
to
> fit into either side of the door frames etc) I've toyed with the idea
of
> using Curtain PIRs mounted above on either side of the doorway,
working in
> a similar way but being possibly easier to fit. The one disadvantage
might
> be that it would "see" pets walking through the door,
whereas a
beam-break
> could be set at a height higher than the pet.
>
> Another thing I'm currently about to fit are some stair pressure mats
> under the chair and settee cushions i.e. I can then detect if someone
is
> sat on a chair. I've done a quick and dirty trail run as proof of
concept
> and it seems to work OK, but I've no idea if they will stand up to the
> constant pressure of someone sat on them.
>
> Marcus
>
> ________________________________
> From: ukha_d@xxxxxxx<mailto:ukha_d%40yahoogroups.com>
[mailto:ukha_d@xxxxxxx<mailto:ukha_d%40yahoogroups.com>]
On Behalf
Of
> Paul Gordon
> Sent: 15 October 2008 10:17
> To: UKHA Group
> Subject: RE: [ukha_d] Room occupancy detection and door
opening/closing -
> 1-wire or wireless solution?
>
>
> Dermot, it strikes me that magnetic door sensors don't actually help
> much in determining room occupation do they?
>
> They just tell you if a door is open or closed. Unless you have
> automatic closers on the doors, either could be a valid state
regardless
> of the room occupancy - my lounge doors for example are routinely left
> open when the room is occupied. Even with automatic closers that just
> narrows down the logic a little bit, so that you can know that if a
door
> is open, someone must be holding it open, & thus presumably
passing
> through... - but it can't tell you in what direction they're going, so
> how will you know whether to count someone out or count someone in?
>
> If you have more than 1 person in the house you can't rely on PIR's
> alone, as they can't discriminate between the movement of a single
body
> or multiple bodies. Even with a combination of magnetic door sensors
and
> PIR's, I can't imagine how you could logically deduce room occupancy
> with any degree of reliability, and certainly not in real-time.
>
> I suppose if you don't care *how many* people are in a room, just
> whether anyone is in there or not, it can be simplified a little, but
II
> sill don't think it would be easy (possible?) to make near real-time
> judgements...
>
> I am assuming of course that the purpose of the exercise is to
determine
> room occupancy in order to do smart things with automation of lights
&
> appliances etc. rather than you having some other requirement for
which
> you just need to determine/count door openings....
>
> In order to do that a bit better, some other technologies, either
> instead of, or preferably in addition to those mentioned would
probably
> be beneficial...
>
> Beam-break sensors in the door jamb would signal someone actually
> passing through the door rather than just opening it. Multiple
> beam-breaks positioned horizontally could even give you the direction
of
> travel (and I guess vertical ones could tell you how tall they were,
> which might be useful if there are kids in the house perhaps?)
>
> Some CCTV systems have some image processing smarts in the software
that
> can count objects & people in this way.. - I know Geovision has
features
> like this for example, so the software can be used (and is designed)
for
> exactly this purpose... - to count people in & out of a room to
maintain
> a record of its occupants...
>
> Not wishing to pooh-pooh the idea, but I've been around on this long
> enough to learn that occupancy detection is pretty much the single
> hardest thing to get right...
>
> HTH
>
> Paul G.
>
> > -----Original Message-----
> > From: ukha_d@xxxxxxx<mailto:ukha_d%40yahoogroups.com><mailto:ukha_d%40yahoogroups.com>
> [mailto:ukha_d@xxxxxxx<mailto:ukha_d%40yahoogroups.com><mailto:ukha_d%40yahoogroups.com>]
On
Behalf
> Of
> > dermot_bradley
> > Sent: 15 October 2008 01:35
> > To: UKHA Group
> > Subject: [ukha_d] Room occupancy detection and door
opening/closing
-
> 1-
> > wire or wireless solution?
> >
> > Hi folks
> >
> > I'm trying to figure out the easiest way to detect room occupancy
and
> > doors being opened/closed from a PC.
> >
> > I already have 4-core telephone cable round around various rooms
and
> > I'm in the process of soldering 1-wire temperature sensors to
this
so
> > it would make sense to use this if possible.
> >
> > One easy way to wire up magnetic door sensors seems to be to use
a
EDS
> > D2PC "low cost 2 channel digital I/O 1-wire card" (as
sold by
> > Homechip) to connect the magnetic sensors to the 1-wire network.
> >
> > As for PIR sensors, I've not yet found a easy way to use them
with
> > 1-wire, mainly due to the requirement for power for the PIRs.
> >
> > I guess I could use a battery powered PIR and wire the contacts
to a
> > D2PC for 1-wire connection.
> >
> > Alternatively I could buy some Visonic wireless PIRs and their
> > Powercode receiver to convert the PIR wireless signals to
seperate
dry
> > contacts and then connect these to D2PC and on to the 1-wire
network.
> >
> > Has anyone on the list tried this sort of thing before? Anyone
have
> > comments or alternative suggestions?
> >
> > Basically I'm intended to use the PIRs and door contacts so that
a
> > program on my homeserver PC can control lights and appliances
(i.e.
> > turn on room lights after X minutes of no movement).
> >
> > I haven't decided what to use for light and appliance control yet
> > either (that's a whole other isseu) but will probably go with
Homeeasy
> > or Domia.
> >
> >
> >
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