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We are investigating durable, cost effective and accurate sensors appropriate for placing within a beehive. Please document any infrared sensor research below.

CTB v6.1 Entrance Dimensions

Hey @mtnscott here are the CTB entrance dimensions.

John Rees - Bee Counter Project

The concept behind the bee-counter is that it enables the user to keep a record of the number of bees entering and leaving the hive. It uses IR reflectance sensors to sense when a bee passes through one of the gates. By having two sensors in each gate it can assume the direction that the bee is travelling in. In theory, with some tweaking it might be possible to estimate if the bee is a drone (male) or a worker (female) based on the bee's size. There is also the possibility of marking the back queen with a blob of paint which would have a high reflective index so you would know if she had left the hive. However, if that happened you are probably too late to stop the swarm so it might be better to look at swarm prediction methods like listening for a certain frequency of sound that some have reported is produced a couple of days before bees swarm.

Read the rest here.

Pololu - QTR-8A

This sensor module has 8 IR LED/phototransistor pairs mounted on a 0.375" pitch, making it a great detector for a line-following robot. Pairs of LEDs are arranged in series to halve current consumption, and a MOSFET allows the LEDs to be turned off for additional sensing or power-savings options. Each sensor provides a separate analog voltage output.

Instructables: Honey Bee Counter

Heres a though - how about the channels from the infrared sensor protrude from the base of the sensor container? I can imaging following the Instructables post above, this could be achieved.

Arduino-DIY Laser / IR person counter

Research Studies
An imaging system for monitoring the in-and-out activity of honey bees

Capacitance-based sensor for monitoring bees passing through a tunnel

A bee counter for monitoring bee activity and bee behaviour [proceedings]

Relevant Bee Dimensions

Apis mellifera

Length: 0.4 to 0.6 inches / 10.16 mm to 15.24 mm (source)

Width (Bee Space): minimum 1/4" 6.4 mm but generally 3/8" (9.53 mm) (source)

Colorado Top Bar v6.1 Hive Entrance: 4.743" L (120.49 mm) x 0.275" (7 mm) Tall (source)

Barcelona Warre v2.4 Hive Entrance: 3.149" (80 mm) L x 0.378" (9.61 mm) Tall (source)

If we use the 9.53mm and add 5.5 for the separator and spacer then we can get 8 channels in the 120mm space of the Colorado Top Bar. We could get 9 channels if we reduce the spacing do 3.5mm

Do we need space between the bee width and the width of the channel? 1, 2, 3mm?

One possible set of dimensions could be -

Colorado Top Bar: 9 channels 11.5mm wide with 2mm separators
Barcelona Warre: 6 channels 11.5mm wide with 2mm separators

On this page http://www.instructables.com/id/Honey-Bee-Counter/ there is some discussion around the queen bee. Should we limit the channel to restrict the queen from leaving? Also are there different bee sizes for different bee types within the hive, workers vs others? Will there be negative effects from too small / too big a channel?

@mtnscott

Should we limit the channel to restrict the queen from leaving?

We'd like the queen to be able to leave for two reasons:

1. We promote natural beekeeping practices
2. The queen leaves when a swarm happens, so this is legitimate behavior

Also are there different bee sizes for different bee types within the hive, workers vs others?
@SenecaUPP @BarefootBee what do you guys say here? Scott is asking if we need different channel widths to travel through (IR sensor development).

We want to maintain Bee Space - 3/8" / 9.53mm for the channels.

Hmm...2mm separators seems small, but only in comparison to the instructables counter - @jonathan @trizcs what do you think - how wide should the spaces between IR counter channels be?

Warre & CTB Entrances

@jonathan - should we just make the hive entrances between the two models the same dimensions? This would make sensor development easier.

@trizcs what do you think?

I think standardising major elements of the hive like the enterences is a good idea, so long as it doesnt conflict with the design!

Good thinking Aaron.

Anything that prevents the queen from leaving is also likely to block drones. Bad idea.

I appreciate the feedback.

So from @AaronM data we will keep the width of the channels at 3/8".

I have another question, do we have any idea how fast bee's walk? I'm writing the software to properly detect a bee passing thru the channel and I wanted to make sure I only counted the bee once. So I would like to understand what to expect from the bee's travel time thru the channel.

@BarefootBee @AaronM @trizcs Do you have any ideas?

I agree with @BarefootBee, a small entrance would not only disallow the queen from possibly leaving with a swarm, or perhaps a new queen from going/returning on a mating flight, but will disallow drones to come and go. Is there a way to distinguish which bees are coming and going?? A way to sense worker bees vs a queen or drone activity??

BUT! "Bee space" is large enough for all bees to pass through- just not sure how we would tell the difference between them which could be very important and informative data.

@mtnscott I would assume the speed I'm which bees walk would be variable. This might be absurd, but is there a way to count their steps instead?...