Project:LHS Graphs and Visualizations: Difference between revisions

Project:LHS Graphs and Visualizations (view source)

332 bytes added , 18 December 2010

1,649

edits

@@ Line 17: / Line 17: @@
 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 - can we detect some other event such as the door opening after a prolonged lights-out period to force the count to zero ?
+* This will probably get caught out by clusters of people:
+** We only need an approximate count
+** The doorway is narrow so it's unlikely the two people will step through together, if they do - see point above
+** 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?
+** Yes, we can fuse the sensor data with the door/lights data if  we get large amounts of drift - but I don't plan to just yet
 These sensors appear to be in working order. They'd should be safe to use below child-head height. They were manufactured in 1996 and use a Class II laser rated at 3mW with a wavelength of 655-670nm ([[Media:Banner-q45bb6ll.pdf|datasheet]]).