RE: Controllerless distributed automation

[Mark Harrison <mark.harrison@xxxxxxx>]

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How about:

Each device sends a broadcast to every other devices whenever it changes
state (either because it decides to because it wants to, or because it is
manually triggered.)

Each device "listens" to every broadcast, and then tries to work
out whether
it needs to change state.

BUT

Rather than making this determination based on a set of preconfigured
rules,
it instead builds up a "historical usage profile" using
KnowledgeBase
techniques.

The downside is that you spend the first few weeks having to change
everything manually. The upside is that you don't have to think about it.

I gather that some of the high-end CEDIA stuff now works this way.


It does somewhat rely on having _all_ the inputs avaialble: eg IR, RF from
legacy controllers, thermostats, all light switches _broadcasting_ state
changes, occupancy detectors, volume detectors...

Mark



-----Original Message-----
From: Paul Gordon [mailto:paul_gordon@xxxxxxx]
Sent: Wednesday, February 14, 2001 11:57 PM
To: ukha_d@xxxxxxx
Subject: Re: [ukha_d] Controllerless distributed automation


Hi David,

>
>I don't think it needs to be that complex, as long as devices are aware
>of _relevant_ neighbours and their status, they don't need (or want)
>complete information.  Would the room stat need to know which TV
channel
>I'm watching?  (OK, having said that, somebody'll come up with a really
>good reason why it might, but you get the idea :-)

That's a fair point, but it does serve to illustrate part of the problem,
who (or what) decides which neighbours are relevent to each other? - if a
room thermostat does not "know" that the actions of a light
switch in the
same room are relevant to it's operation, then might not the heating stay
on

way beyond the time the room has ceased to be occupied? - Actually,
occupancy detection is a really good one to test out any system on, as this
has been discussed at >great< length before, and the groups'
collective
expertise has yet to come up with a failsafe system....But, my point is,
that unless the room thermostat knows the difference between a thermostat
and a light switch, how is it to know that it does not care about that
difference? - with a distributed intelligence system, you have to think
about these things. - any component >must< have a knowledge of it's
environment in order to interact successfully within that environment...




>
>At the moment I'm trying to figure out just what is useful information,
>and what constitutes a "relevant neighbour" before even
starting to
>worry about communications protocols or physical networking.  There's a
>lot to think about....
>

You got that right!


> > (snip)
>
>Erm, I thought you were in favour of distributed systems, or are you
>just playing devil's advocate? :-)  [cf the "Flight of
fantasy" thread]
>

OK, you got me, - you're right, I am broadly in favour of a distributed
intelligence model, but only to a certain point. - I don't yet see the
technology available to implement such a model (at reasonable cost). You're
example (frivolous as it may have been ), of a light switch with 1Ghz CPU
and 128MB RAM, will no doubt be with us one day in the not-too-distant
future, but (and this is the important bit), >NOT< today, and
>NOT< tomorrow

either. (much to my chagrin) (and undoubtedly yours too?)
I would dearly like such a system to be a reality, but unfortunately, it is
a reality only for those fortunate individuals in the lottery winners
enclosure!


> >THIS is exactly what I proposed a month or two ago in the thread I
>started
> >called "flight of fantasy" - I even went as far as to
describe (in loose
> >terms) how such elections could be coordinated and controlled,
with
> >heartbeats, assigned priorities and so on.
>


>I missed/skipped this originally as things were incredibly busy at work
>(lots of late nights) plus I was house hunting at the same time.  I've
>gone back and read all the messages from then, and it looks like I
>missed a lot of interesting discussion.  Unfortunately your doc isn't
>available from the Yahoo archive - any chance you could fire a copy off
>to me?


For sure, - give me a day or three, I'm in the same situation at the mo -
working stupid hours..... (hence I may be rambling incoherently!), but if I
haven't mailed you by Sunday, then please remind me...


>
> >This in my opinion, is actually the better "ideal"
system - any
>objections
> >(which are valid ones, don't get me wrong!) to having a
"single point of
> >failure" are negated by providing redundancy of the central
controller
>role.
>
>The reliability argument is really a minor one.  As you rightly point
>out, these systems are very reliable, and I'd actually expect my
>home-brew bits and pieces to be worse as far as MTBF goes.  It's more
of
>an experiment/research idea really, just to see what might be possible.

Keep up the good work, - 'cos if anyone comes up with a solution, it will
be

a goldmine!!

>
> > (snip)
> >
> >Just my £0.02
>
>Cheers!  Any comments are useful, especially from someone who's been
>thinking about this for longer than I have.
>
>DP
>

It's just a shame that thinking about it is all I have time to do!

Cheers.

Paul G.


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