Occupancy detection
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Posted by Robert Green on August 2, 2007, 11:28 pm
Please log in for more thread options current state of occupancy detection. Even X-10 at its smartest is pretty dumb when it comes to turning out lights that you're not really using and conversely NOT turning out lights that your ARE using (i.e. longer than average bathroom stays.) The article got me to thinking about how dogs do "occupancy detection" and where AI could play an important part of light control, conservation and "wellness detection" for want of a better term. *************************************************************** http://wtop.com/?nid=106&sid=1169767 Can Motion Sensors Predict Dementia? June 18, 2007 - 4:15pm By LAURAN NEERGAARD AP Medical Writer WASHINGTON (AP) - Tiny motion sensors are attached to the walls, doorways and even the refrigerator of Elaine Bloomquist's home, tracking the seemingly healthy 86-year-old's daily activity . . . to see if round-the-clock tracking of elderly people's movements can provide early clues of impending Alzheimer's disease. . . . The theory is that as Alzheimer's begins destroying brain cells, signals to nerves may become inconsistent _ like static on a radio _ well before memories become irretrievable. One day, signals to walk fire fine. The next, those signals are fuzzy and people hesitate, creating wildly varying activity patterns. *************************************************************** I recently took a tumble down a stairway controlled by an X-10 Hawkeye (OUCH!). As a result, I've come to the conclusion that X-10's motion detectors, while useful in some situations and for some people, are not making the cut when it comes to my house. Ironically, the fall occurred because I was moving very quickly and did not trigger the Hawkeye, which, until I fell, had never failed to turn on that particular light reliably. It's a lot to ask of an HA system to be able to record and analyze speed of travel and travel patterns within a house, but that article made me think we might finally be there, equipment and software-wise. The dog sure knew I was heading down the stairs at a fast clip, but the HA system did not. It could have known, though. Part of the problem with X-10 RF is wire lathing in all the walls blocking radio reception. But I suspect another part of the problem is the growing saturation of the RF band used by the HawkEye/EagleEyes. I tested reception in my house five years ago and where I was reaching 15' between test points in the past, I now only reach 10'. While I'm aware there could be a number of possible causes, the bottom line is that RF-based motion detector signal propagation is not reliable, particularly in dangerous areas like dark stairwells. I've decided instead to investigate the feasibility of using multiple sensors, and incorporating IR light beams across doorway openings to positively detect when someone has entered or exited a room. I've had some success with pressure mats under carpeted areas, but the places that most need automatic light control have concrete, tile or wood floors. If the sensors and light sources are small enough, I could embed them in the door trim pretty easily. I've come across an interesting candidate at: http://www.apogeekits.com/ir_light_barrier_mk120.htm and the price per doorway seems to be right but I have a few concerns. The first is whether I can mount the diodes and detectors remotely on a 10' length of wire without affecting circuit values adversely. The second, more important question is whether putting IR emitters in all the doorways is going to cause more problems for the Powermid and other IR communication devices. The third is whether I can run all the kits from a master power supply without interaction issues. The second half of this equation is what sort of controller is best suited to handling the demands of multiple-sensor, very high reliability occupancy detection? We've discussed this here before, but with WiFi-enabled cell phones and other new, miniaturized wireless devices becoming available, it may finally be possible to tell where every member of the household is, 24 by 7. While it sounds intrusive, think about how much greater the degree of control there would be over personalized automation if the HA system could know who was where, and what they were doing. If they are sitting quietly watching TV, no sudden light flashes. If someone's taking a super-long shower or "other" activity, no sudden darkness. The system would be able to respond to rules like "if no motion is detected *but* no one has left the bathroom, leave the light on." This one ability would shoot SAF (and my own AF) up considerably and it should be doable unless someone climbs out the bathroom window. Turning off lights as soon as rooms became empty (instead of after X minutes) and being able to provide "light pathways" as a person walks along through a darkened house should shave some serious $ off the electric bill. If FPS games can track hundreds of actors across multiple continents in huge simulated terrains the CPU horsepower is obviously available to track two slow moving people and two somewhat livelier little dogs in a rather small residence! Any thoughts or relevant information will be appreciated. -- Bobby G. | ||||
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Posted by Dave Houston on August 3, 2007, 6:32 am
Please log in for more thread options 1. There's no reason to think the various motion detectors are saturating the RF environment. They only transmit for a very brief period (5 bursts that last about 65mS each) when triggered by motion so unless someone in the household is now constantly wandering about aimlessly (or purposefully, for that matter), RF activity attributable to the motion sensors should remain more or less the same over time. The decrease in range could be caused by any number of things - weaker batteries, higher humidity, temperature, etc. 2. The IR used in the types of sensors you are considering is usually of a different wavelength and does not modulate a 38-40kHz carrier and IR is also line-of-sight so it's unlikely to affect the Powermids. | ||||
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Posted by Robert Green on August 3, 2007, 4:32 pm
Please log in for more thread options > Just a couple of points...
the
> > 1. There's no reason to think the various motion detectors are saturating > the RF environment. They only transmit for a very brief period (5 bursts > that last about 65mS each) when triggered by motion so unless someone in > household is now constantly wandering about aimlessly (or purposefully,
for
> that matter), RF activity attributable to the motion sensors should remain
etc.
> more or less the same over time. The decrease in range could be caused by > any number of things - weaker batteries, higher humidity, temperature, The RF range has decreased over time, and I did not mean to imply it's from the RF detectors "saturating" the environment. There are times in the morning now where the X-10 RF flat out doesn't work unless you put a Palmpad or keychain remote within a few feet of the transceiver. Whether these blackouts are caused by sunspots, military transmissions or whatever, I can't say. Without an RF meter it's just guesswork. However, one doesn't need to know the cause to see the effects. They are pretty hard to ignore. When it happens, all the wireless thermometer displays either go blank or fail to update. That sort of unreliable environment makes occupancy and motion detection using the X-10 RF frequency unworkable, at least IMHO. The lax enforcement by the FCC tells me things will get worse and not better as more and more wireless gizmos make their way to market. More importantly, the apparent lack of collision detection of the RF component of the "chain of command" means that if there's more than one person and one detector in the house, problems are bound to occur. I've tried all sorts of combinations of transceivers. The protocol's just not robust enough to support the task, at least in a house where there's fast motion of more than one occupant. When I lived alone, I recall being skeptical about all the problems people reported with multiple occupants and motion detectors. Not anymore! > 2. The IR used in the types of sensors you are considering is usually of a
also
> different wavelength and does not modulate a 38-40kHz carrier and IR is > line-of-sight so it's unlikely to affect the Powermids.
That's good news. I was worried because I didn't think either the sun, CFL's or plasma TV's modulated a carrier or worked on the Powermid wavelengths but managed to trash IR distribution just the same. Like mercury in CFLs, I hate solving one problem by inducing others! I guess I'll plunk down some bucks and buy a few of the kits: http://www.apogeekits.com/ir_light_barrier_mk120.htm and see what's what. They're not very expensive. Thanks for the input, Dave. -- Bobby G. | ||||
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Posted by Dave Houston on August 3, 2007, 5:22 pm
Please log in for more thread options
>The RF range has decreased over time, and I did not mean to imply it's from
>the RF detectors "saturating" the environment. There are times in the >morning now where the X-10 RF flat out doesn't work unless you put a Palmpad >or keychain remote within a few feet of the transceiver. Whether these >blackouts are caused by sunspots, military transmissions or whatever, I >can't say. Without an RF meter it's just guesswork. So just how close to the Naval Observatory are you? | ||||
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Posted by Robert Green on August 4, 2007, 6:38 am
Please log in for more thread options >
> >The RF range has decreased over time, and I did not mean to imply it's
from
> >the RF detectors "saturating" the environment. There are times in the
Palmpad
> >morning now where the X-10 RF flat out doesn't work unless you put a > >or keychain remote within a few feet of the transceiver. Whether these
> >blackouts are caused by sunspots, military transmissions or whatever, I > >can't say. Without an RF meter it's just guesswork. >
> So just how close to the Naval Observatory are you? Apparently too close. I also believe I am in a straight line path between two large military installations active in Homeland security work. From what I can see each has several huge towers with all sorts of different antennas pointed my way. Not sure what bands the transmit on or even if they are involved but the blackouts are becoming more and more frequent. At first, I thought there was something wrong with the wireless thermometers and kept changing batteries only to find they hadn't run down more than half a volt. That's when I noticed the bathroom lights would misfire, despite the close proximity of the TM751 to the Hawkeye. I'd reset all the thermometers so that they had blank displays and when they finally refreshed, the RF "storm" seemed to be over. The bathroom light goes on and off nearly instantaneously when the RF skies are clear and becomes quite erratic when the thermometer displays "lock up." I can only assume it's a stronger signal drowning out the flea-powered devices like the Hawkeyes and the thermometer transponders. For me, the really bothersome part of the problem is that in many, many cases, the darn things work just fine. You can hardly get more bang for your buck, especially if, like me, you got the X-10 gear with the vouchers they used to hand out like candy. To get to the next quantum level of reliability means you have to basically leave the X-10/RF world and go multiple sensor and hard wire or an use RF protocol that's two way with collision detection. Even so, my front tooth, my costochondral separation and my patella are working hard to convince me that near the Nation's Capital I might be wise to cut RF completely out of the loop if I want to maximize reliability. I have *so* many Hawkeyes that I'd be willing to try hacking a few to disable the RF transmission feature and use their output to close contacts or otherwise act as sensors in a hard-wired system. Or I might decide that the X-10 RF component can act as a secondary or tertiary sensor in a multiple sensor setup, with the primary motion detector being the hardwired broken IR beam sensors. I like the beam because it's immune to all but leaping pets, flying bats and couples crossing the barrier "in flagrante delicto." The problem becomes how to integrate the critical lights into the X-10 system while maintaining isolation from some of the typical X-10 problems of collisions, inadvertent activations and lost commands. I'd like to still be able to turn all the houselights out with a single button press but that feature makes the stairway lights vulnerable to someone pressing the ALL LIGHTS OFF switch while someone else is descending the stairs. The stairways lights should only respond to X-10 commands if no one is using the stairs. -- Bobby G. | ||||
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>current state of occupancy detection. Even X-10 at its smartest is pretty
>dumb when it comes to turning out lights that you're not really using and
>conversely NOT turning out lights that your ARE using (i.e. longer than
>average bathroom stays.) The article got me to thinking about how dogs do
>"occupancy detection" and where AI could play an important part of light
>control, conservation and "wellness detection" for want of a better term.
>
>***************************************************************
>http://wtop.com/?nid=106&sid=1169767
>
>Can Motion Sensors Predict Dementia?
>June 18, 2007 - 4:15pm
>
>By LAURAN NEERGAARD
>AP Medical Writer
>
>WASHINGTON (AP) - Tiny motion sensors are attached to the walls, doorways
>and even the refrigerator of Elaine Bloomquist's home, tracking the
>seemingly healthy 86-year-old's daily activity . . . to see if
>round-the-clock tracking of
>elderly people's movements can provide early clues of impending Alzheimer's
>disease. . . . The theory is that as Alzheimer's begins destroying brain
>cells,
>signals to nerves may become inconsistent _ like static on a radio _ well
>before memories become irretrievable. One day, signals to walk fire fine.
>The next, those signals are fuzzy and people hesitate, creating wildly
>varying activity patterns.
>
>
>***************************************************************
>
>I recently took a tumble down a stairway controlled by an X-10 Hawkeye
>(OUCH!). As a result, I've come to the conclusion that X-10's motion
>detectors, while useful in some situations and for some people, are not
>making the cut when it comes to my house. Ironically, the fall occurred
>because I was moving very quickly and did not trigger the Hawkeye, which,
>until I fell, had never failed to turn on that particular light reliably.
>It's a lot to ask of an HA system to be able to record and analyze speed of
>travel and travel patterns within a house, but that article made me think we
>might finally be there, equipment and software-wise. The dog sure knew I
>was heading down the stairs at a fast clip, but the HA system did not. It
>could have known, though.
>
>Part of the problem with X-10 RF is wire lathing in all the walls blocking
>radio reception. But I suspect another part of the problem is the growing
>saturation of the RF band used by the HawkEye/EagleEyes. I tested reception
>in my house five years ago and where I was reaching 15' between test points
>in the past, I now only reach 10'. While I'm aware there could be a number
>of possible causes, the bottom line is that RF-based motion detector signal
>propagation is not reliable, particularly in dangerous areas like dark
>stairwells.
>
>I've decided instead to investigate the feasibility of using multiple
>sensors, and incorporating IR light beams across doorway openings to
>positively detect when someone has entered or exited a room. I've had some
>success with pressure mats under carpeted areas, but the places that most
>need automatic light control have concrete, tile or wood floors. If the
>sensors and light sources are small enough, I could embed them in the door
>trim pretty easily.
>
>I've come across an interesting candidate at:
>
>http://www.apogeekits.com/ir_light_barrier_mk120.htm
>
>and the price per doorway seems to be right but I have a few concerns. The
>first is whether I can mount the diodes and detectors remotely on a 10'
>length of wire without affecting circuit values adversely. The second, more
>important question is whether putting IR emitters in all the doorways is
>going to cause more problems for the Powermid and other IR communication
>devices. The third is whether I can run all the kits from a master power
>supply without interaction issues.
>
>The second half of this equation is what sort of controller is best suited
>to handling the demands of multiple-sensor, very high reliability occupancy
>detection? We've discussed this here before, but with WiFi-enabled cell
>phones and other new, miniaturized wireless devices becoming available, it
>may finally be possible to tell where every member of the household is, 24
>by 7. While it sounds intrusive, think about how much greater the degree of
>control there would be over personalized automation if the HA system could
>know who was where, and what they were doing.
>
>If they are sitting quietly watching TV, no sudden light flashes. If
>someone's taking a super-long shower or "other" activity, no sudden
>darkness. The system would be able to respond to rules like "if no motion
>is detected *but* no one has left the bathroom, leave the light on." This
>one ability would shoot SAF (and my own AF) up considerably and it should be
>doable unless someone climbs out the bathroom window. Turning off lights as
>soon as rooms became empty (instead of after X minutes) and being able to
>provide "light pathways" as a person walks along through a darkened house
>should shave some serious $ off the electric bill.
>
>If FPS games can track hundreds of actors across multiple continents in huge
>simulated terrains the CPU horsepower is obviously available to track two
>slow moving people and two somewhat livelier little dogs in a rather small
>residence!
>
>Any thoughts or relevant information will be appreciated.