Project:Spacensus: Difference between revisions

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I have located two Laser Diode Retroreflective Sensors in our stores which I intend to use to monitor space occupancy by having the beams cross the main doorway. The beams will be staggered so that direction (arriving, leaving) can be determined by the order in which the beams are broken. I was thinking of mounting them at waist height.
I have located two Laser Diode Retroreflective Sensors in our stores which I intend to use to monitor space occupancy by having the beams cross the main doorway. The beams will be staggered so that direction (arriving, leaving) can be determined by the order in which the beams are broken. I was thinking of mounting them at waist height.


* This will probably get caught out by clusters of people: --[[81.105.17.61]]
** We only need an approximate count
** The doorway is narrow so it's unlikely that the steps of more than one individual will overlap.
** Most of the time people won't arrive in clusters
* Can we detect some other event such as the door opening after a prolonged lights-out period to force the count to zero? --[[81.105.17.61]]
** Yes, using the door/lights data for reset would be good if  we get large amounts of drift - but I don't plan to just yet
** This might fail if people spend the night there.  AIUI this happens rarely enough that we may not care about the inaccuracy.
** We could also use some kind of probabilistic model with the 'door-open' and 'bell' data


==Location==
==Location==
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==What next==
==What next==
Spacensus still miscounts - especially when the door is opened for an incoming guest. I am aware of a few issues in the code where detection could be improved so will try a couple of modifications and see how it goes.
Spacensus still miscounts - especially when the door is opened for an incoming guest. I am aware of a few issues in the code where detection could be improved so will try a couple of modifications and see how it goes.
==FAQ==
Q: This will probably get caught out by clusters of people: --[[81.105.17.61]]
A:
* We only need an approximate count
* The doorway is narrow so it's unlikely that the steps of more than one individual will overlap.
* Most of the time people won't arrive in clusters
Q: Can we detect some other event such as the door opening after a prolonged lights-out period to force the count to zero? --[[81.105.17.61]]
A:
* Yes, using the door/lights data for reset would be good if  we get large amounts of drift - but I don't plan to just yet
* This might fail if people spend the night there.  AIUI this happens rarely enough that we may not care about the inaccuracy.
* We could also use some kind of probabilistic model with the 'door-open' and 'bell' data
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