# Crowdfunding for bee reserarch



## JSL (Sep 22, 2007)

Peter, all the best wishes to you in your research project!

If I my ask, how will you account for the interruption of collecting and weighing all of the returning foragers. The reason I ask is because I had a similar project as a graduate student. I was not collecting all of the returning foragers, but a percentage to evaluate pollen and nectar loads for a learning study.

Again, all the best as it is certainly an challenging study!


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## pberx (Feb 21, 2016)

Hi

Thanks for the reply. You made a good point here.
I don't catch bees in order to count or weigh them. In fact, they will be counted - and weighed - by passing trough a "bee counter", a series of small gates, placed in front of the hive entrance, each equipped with 2 IR sensors, who detect the passage of a single forager.
At the bottom of each 'gate', there is a miniature load cell that is measuring the weight of each passing bee. So, all entering and leaving forager bees are counted and weighed without hindering them.
The counting with IR sensors is maybe not new. The fact that it will be combined with realtime weighing is. I want to combine these measurements with an overall weighing of the hive and several other parameters. The goal of this research is to try to determine which part of the weight 'pro bee' is nectar and which is pollen to get an overall picture of these resources entering the colony each day. And how are they allocated for brood, homeostasis and winter supply. 
I hopes this answers your question.

All the best

Peter


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## JSL (Sep 22, 2007)

Thank you Peter, I assumed the counting would be done electronically, but I am unclear as to how you will differentiate between nectar, water, propolis and pollen. That was one of the challenges I faced as I had to determine nectar volumes and concentrations as well as pollen loads. It was a while ago...so I was curious to know if someone figured out a more efficient method.


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## deknow (Jul 17, 2006)

> how you will differentiate between nectar, water, propolis and pollen


Duh! ..the taste.


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## JSL (Sep 22, 2007)

deknow said:


> Duh! ..the taste.


I tried that, but I kept getting stung...


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## Phoebee (Jan 29, 2014)

This is a complex task indeed.

Developing a load cell for individual bees sounds like a fun possibility. It certainly is possible to make one that delicate (I've built custom load cells many years ago, and have been considering a purpose-built hive scale load cell). But the dynamics will be challenging. Bees coming in with forage tend to be in a hurry, never standing still and willing to run each other over in their hurry to get inside. While it is possible (and is probably the easier problem) to make a load cell for individual bees, I suspect you will need to put considerable time into signal processing to tease out the actual bee weight. Fortunately, a lot of modern A/D converters have processors built-in.

The gate and channel system may prove to be a choke-point during periods of high traffic. When a flow is on we usually pull entrance reducers entirely, so I would expect you would need these devices across the full front of the hive. This may get into the problem of the measurement affecting what is being measured.

Video of each gate, with automatic image analysis, might allow pollen grain size and color to be measured. This could be extremely valuable data. Again, the processing power required for each video channel is tremendous.

Regarding the fundraising goal you have set, I'd guess you're underfunding by at least a factor of 5. You could develop a few sensors for what you are estimating, but I don't think you can build enough of them for that. A full university study would probably be asking for a grant of not less than $100k.


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## deknow (Jul 17, 2006)

There are some interesting notes available online for detecting bees by running them through a coil and measuring the capacitance change. 

I wonder if you had the bees walk through tubes that were tight for the bee, and concentricly inside a coil if you could use the change in capacitance to derive the mass...or at least some kind of relative mass.


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## pberx (Feb 21, 2016)

Sorry about the delay in replying. Well, if you assume that a bee weighs less when she leaves than when she arrivés, you can calculate for the difference. This test is set up to see how you can determine which part in that difference in weight is pollen, which is nectar and which is water.
I hope that the test will show there is a weight difference in bees arriving with just pollen, just nectar or pollen and nectar. Water is something I need to find out how to fit it into the measurements. Maybe the weighing data will show that water carrying bees also have a different weight.
Besides, I will start by "calibrating": weighing 'empty' bees, and bees with different loads, weighing pollen lumps... And there will be a camera set up at the entrance so I can count the arriving foragers with pollen loads at different times per day.
But if you have some interesting suggestions, I'll be happy to hear them. If you like you can also contact me at [email protected]

Peter


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## pberx (Feb 21, 2016)

Hi Phoebee. Thanks for the valuable input.

I don't develop a load cell; they already exist. It took me a year to find load cells that are able to detect weights in the range of 0.1 g. But finally I've found some. They make up for 40% of the calculated budget of this project.
I hope I'm not underfunding. I've looked up all the prices and made the budget accordingly. Wages are not included in the calculation. This is sort of a hobby project, but I'm fortunate I work in a bee center where I'm allowed to work on this during working hours.

You're certainly right by pointing out that the gate and channel system can prove to be a choke-point but this system (with the IR sensors but without load cells) has already been built. Check "Bee counter" on www.instructables.com. 
There will be video at the entrance and you are right to point out that this will be a challenge to process this. But image analysis is not (yet) included in this small project.

If this turns out well, all building instructions will be posted on www.instructables.com so that other people can use it.



Phoebee said:


> This is a complex task indeed.
> 
> Developing a load cell for individual bees sounds like a fun possibility. It certainly is possible to make one that delicate (I've built custom load cells many years ago, and have been considering a purpose-built hive scale load cell). But the dynamics will be challenging. Bees coming in with forage tend to be in a hurry, never standing still and willing to run each other over in their hurry to get inside. While it is possible (and is probably the easier problem) to make a load cell for individual bees, I suspect you will need to put considerable time into signal processing to tease out the actual bee weight. Fortunately, a lot of modern A/D converters have processors built-in.
> 
> ...


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## Phoebee (Jan 29, 2014)

pberx said:


> Well, _*if you assume *_that a bee weighs less when she leaves than when she arrivés, you can calculate for the difference. This test is set up to see how you can determine which part in that difference in weight is pollen, which is nectar and which is water.
> 
> Peter


There will be times, especially in cold or bad weather, when many or most of the bees will weigh less when they arrive than when they left. The phenomenon of "cleansing flights" might throw your results off _*"if you assume"*_ the wrong thing. I watched cleansing flights of bees that had been held in an observation hive for too long. When released, some were unable to fly until they'd staggered for a while and taken a dump. Others plummeted over a ledge and got their relief on the way down, only then managing to pull out of their dive. I saw several relieve themselves airborne, visible from twenty feet away. The weight change can exceed what they are able to fly with.

I would suggest that direction while passing the load cell might be determined by a pair of light beams and a quadrature decoder.

A friend of mine is starting to work with a small circuit board called a NVidia Jetson TX1. It seems to be about the size of a playing card. Its processing speed is rated at > 1 teraFLOP, making it more capable than the best supercomputer in the world in 1996. It is set up for image processing, capable of processing 4K ultra-high-def images. Something like this could be a real key to using HD images to analyze bee behavior.


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## deknow (Jul 17, 2006)

1. Yes, the direction can be determined with a pair of detectors....a simpler (and maybe good enough) way is to divide each entrance with a diagonal divider so the bees are funneled into an entrance from the outside, and an exit from the inside.

2. At WAS (2014), Jerry Hayes showed some impressive image processing/data collection that monsanto had been working on.


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## deknow (Jul 17, 2006)

I'd be concerned about the inherent error in weighing a moving insect....I think about trying to weigh a cat....you can't get a reading until (unless) it stops moving.

Maybe more useful data could be obtained by closing off the entrance at a specific time, collecting and weighing the mass of bees returning to the hive rather than trying to weigh each bee. My gut tells me that if you weigh each bee and add it up, you won't end up with same (probably more accurate) weight of weighing the mass of bees at once.....then you could March them back into the hive amd at least count the ones with pollen loads....maybe a spectroscopic reading of the workers abdomen (as she marches through a tube single file) could determine water vs nectar (maybe distinguish between nectars).

If you closed the entrance at 2pm (and provided a box of known weight and a queen substitute for the bees to return to), you could at least count the bees, maybe determine what they were doing out of the hive, and weigh the mass easily.


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## BadBeeKeeper (Jan 24, 2015)

While this is just the sort of thing that appeals to my inquisitive/experimental tech side, I am seeing an issue that does not appear to to have been accounted for in what has been posted so far.

Having been formerly employed in the trucking industry, a similar method was used to determine the weight of the loads on trucks- weigh empty, weigh loaded, difference is the weight of the load- but you have to know exactly which truck each set of weights belongs to, or the results are useless, because the trucks do not all weigh the same when empty (also, variation in fuel level).

My bees are not all the same size, and presumably, not all equal in weight either.

So, the following questions come to mind:

What is the variation in weight between individual bees? (Margin of error)

What is the carrying capacity of bees in (a) water, (b) pollen, and (c) nectar? (Margin of error)

How much does the carrying capacity (of each type of load) vary between bees? Margin of error)

How does the 'bee weight' variation compare to the 'load capacity' variation?

What about bees that return loaded at less than full capacity?

How can all of these variations be accounted for, and what methods can be used to discriminate and isolate the variables?

Pardon me for being skeptical, but at this point I fail to see how meaningful results can be achieved, and in particular, results that would be any more meaningful than simply weighing the hive in the morning and at night. This seems to me to be a Rube Goldberg approach to a simple task...except that the typical Goldberg machine is usually expected to accomplish the task for which it was designed.

Note: I am completely ignorant as to the possible values of the variations mentioned (AND, I suck at math). This is not intended to be a criticism, rather, a request for enlightenment in what may be a mistaken perception.


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## Phoebee (Jan 29, 2014)

If the bees are being photographed, it would certainly be possible to tag the thoraxes of at least a few with something machine-readable. Numbered tags are used when researching them all the time now. 

It seems unlikely, but only experience would tell ... possibly bees can be identified individually from photographs. Unique hair patterns on their backs? Unique veins in their wings? I would go bonkers if I tried to do this myself, but maybe that playing-card supercomputer could handle it. If so it would be a remarkable research tool.


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## pberx (Feb 21, 2016)

Hi

That is indeed a lot of - usefull - information.
Do not think that I didn't considered all this. You are absolutely right to point out all these obstacles. But to call this a Rube Goldberg approach seems to me a bit far fetched.
I certainly consider the fact that the whole system won't be accurate enough - or maybe will be to accurate - to determine food supply brought into the hive.
That is exactly why we only test with three hives: it is a test project. If this turns out not to be working we have to see what has to be changed in order to get better data. Or, we have to conclude it was indeed a Goldberg machine.
The fact that it was not included in the project description on the website is only because of lack of space and the fact that it has to appeal to the general public in the first place. A too elaborate description of the project is not interesting enough.
We discussed it thoroughly here with beekeepers and scientists and we are well aware of the difficulties. But the setup looks interesting enough to give it a try.



BadBeeKeeper said:


> While this is just the sort of thing that appeals to my inquisitive/experimental tech side, I am seeing an issue that does not appear to to have been accounted for in what has been posted so far.
> 
> Having been formerly employed in the trucking industry, a similar method was used to determine the weight of the loads on trucks- weigh empty, weigh loaded, difference is the weight of the load- but you have to know exactly which truck each set of weights belongs to, or the results are useless, because the trucks do not all weigh the same when empty (also, variation in fuel level).
> 
> ...


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## BadBeeKeeper (Jan 24, 2015)

pberx said:


> That is indeed a lot of - usefull - information...But to call this a Rube Goldberg approach seems to me a bit far fetched...If this turns out not to be working we have to see what has to be changed in order to get better data. Or, we have to conclude it was indeed a Goldberg machine.


LOL, I think you misunderstand me. I appreciate the thought and ingenuity that goes into the design of a Goldberg machine. The appellation is not an insult and is not meant to imply that a 'Goldberg approach' is a failure- quite the opposite, Goldberg machines are typically marvels of design and construction and actually accomplish the tasks for which they are designed and I admire such things greatly.


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## pberx (Feb 21, 2016)

Don't worry, I don't consider it as an insult. As much as I admire Goldberg machines as well, I understand quite well why you used the term. But indeed, as much as a Goldberg machine performs the task intended, by it's very nature is far too complex for it. 
I appreciate very much your remarks and I agree that there are a lot of variables that maybe are impossible to calculate or measure. We'll see.


BadBeeKeeper said:


> LOL, I think you misunderstand me. I appreciate the thought and ingenuity that goes into the design of a Goldberg machine. The appellation is not an insult and is not meant to imply that a 'Goldberg approach' is a failure- quite the opposite, Goldberg machines are typically marvels of design and construction and actually accomplish the tasks for which they are designed and I admire such things greatly.


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## grozzie2 (Jun 3, 2011)

pberx said:


> I don't develop a load cell; they already exist. It took me a year to find load cells that are able to detect weights in the range of 0.1 g. But finally I've found some. They make up for 40% of the calculated budget of this project.


I'd be interested in the specs on those load cells. Is 0.1g the range, or the precision ? A quick ask of google suggests there are about 4000 bees in a pound of bees, which is 454g. Round numbers say, a bee weighs roughly 0.1g. I would expect the load carried by the bee to be somewhat less than it's overall weight, and if we take a quick look into the aerospace industry, flying machines typically carry roughly 1/3 of the 'all up' weight in the form of payload. So as a first approximation, if the bees are similar, then the load carried by an individual bee would in the range of 0.03 grams per trip. to get good meaninful data, I would posit that the data needs to be across the range of 0 to 2 grams per bee, with 0.01 gram increments.

I keep a hive on a scale, have had it set up for 2 and a half years continuously. This exercise has taught us some valuable 'real world' things that come into play. Just as an example, it's pouring rain right now outside. In the last couple of hours, hive weight has gone up by a half pound. I now understand that detail much better, and if the rains stop, sun comes out, it'll drop by that amount over a period of 15 minutes. What we are seeing is this. Currently, water is collecting on the outer cover, and running down to the ground, there is about a half pound of water on the lid. That will run off and dry out quickly when the sun hits the hive. Turns out, the hive scale is a relatively reliable proxy for a rain guage. Sometimes my wife will ask in the morning 'how hard did it rain last night', and I'll peek at the overnight data from the scale. A rainfall rate of 1 inch an hour (which is a very heavy rainfall) will bump the hive up by a pound and a half for the duration of the rain event.

The other detail that almost became a show stopper for this project, until I understood it a lot better, was temperature effects on the load cell. Electronic scales that we buy off the shelf in general work on the same principle, turn them on and they will go thru a process, then set the reading to zero. If you then put a fixed weight on it, and start logging data from the scale, you will see it shifts over time, and there is a very precise correlation between ambient temperature and that reading. Load cells respond to weight, temperature, and humidity. It turns out with a beehive on an electronic scale, the predominant response is actually temperature. When we first put the hive on the scale, I would see 5+ pound swings between day and night at times, daytime temps in the 25C range, night time temps in the 5C range, with an overall weight in the 100lb range sitting on the scale. I developed a calibration for our scale the hard way, left it sit for an extended period (over a month) with a fixed known weight on, located such that it was exposed to temperature fluctuations, but using a brick of steel (anvil actually) as the dead weight, something that will not absorb moisture with humidity changes. Using that data, I was able to develop a proper calibration for my load cell. My system records ambient temperature and scale readings for every interval, without the temp data, the scale readings are more useful as a thermometer than they are as a scale.

The other issue I eventually ran into, after a long extended run (2 years) with a hive on that scale, it started to produce very erratic readings last december. At first we thought it was an artifact of having moved the whole system from the yard behind the house, out to the bee yard where I've had power installed recently. Turns out, that wasn't the problem at all, the problem was the load cell just became unstable after 2 years of having a fixed weight set on it, and exposed to way to much weather. I replaced the scale with a brand new one, same make and model. What was REALLY interesting to note, is comparing the two when the new one arrived. A dead weight placed on the old one read 87lb, but that same weight on the new one, 98lb. Most load cells involve strain measurements on a known cantilever of some type, and I think that after 2 years of continuous weight on the cell, the cantilever had actually deformed slightly, so readings were starting to be 'way off'.

I have 2 and a half years of data, 5 minute increments, from the first scale. Looking at the data with an eye for when the problem started, it becomes blatantly obvious, the first sign of erratic readings happened in November, it got a little worse in December, then in January the readings just got totally erratic and wild. I have tentatively added 'replace load cells' as a 2 year scheduled maintenance item for the hive scale project.

Some other tidbits we have learned, that just make sense when we start to understand the data better. We live in a wet coastal climate, and thru the winter, rain is incessant, and at times constant for weeks. A lot of folks ask me about how the hive loses weight during the long bouts of weather where the bees cant fly, and are surprised by the answer. Answer is, hive doesn't lose weight during those periods. BUT, on the first opportunity to fly after 3 weeks of confinement, it's not unusual to see overall hive weight go down by 3 pounds in an hour. When that happens, almost without fail, we will see lots of yellow spots show up on the cars in the driveway.

My data is colony level, and to date, I've made no attempt to gather any data at a smaller granularity. The first lesson early on was, there is plenty of noise in the data, and it takes some significant processing to remove the nose and isolate the specific signal we are looking for. Temperature and humidity took some work to understand. The other big item for us, I wanted graphs that give a constant view of colony progression, so we had to develop a way of isolating and removing 'beekeeper interference' from the data as well. That involves weighing everything that gets put on the hive in the form of empty supers, then weighing again as they come off. I was able to automate that part pretty easily in the scripts that generate our final output graphs, if the hive weights 101lb on one measurement, then weights 126 on the next, it's pretty obvious that somebody stuck on an empty super that weighs 25lb during that time. An explanation of the process, along with 'before and after' correction graphs is outlined here:-

http://www.rozehaven.ca/farm/?page_id=87

The point of my long ramble, as we did, you will likely stumble on some significant sources of noise in the raw data, and when you do, it's going to take some head scratching to understand what it is, then more head scratching (and some ugly math) to work that noise source out of the data. It took me a year to get things running smoothly, to the point where we rarely spend time trying to figure out 'what is this data bump from?', and have a high level of confidence that the scale data is being processed to show the specific signal we are intent on capturing, and that's a real time readout of how the honey flow is progressing thru the season.


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## Phoebee (Jan 29, 2014)

Temperature effects on the load cells were what stopped my hive scale project, when I was attempting to use the measuring feet from cheap electronic hive scales. Those seem to be strain gage based but I'm having my doubts. I was getting not just zero drift, but also scale factor shifts over temperature, which really complicates calibration.

What I expect to end up with is purpose-built instrumented hive supports, with strain gages. If strain gages are properly matched to the metal they are applied on, their coefficients of expansion match, and there is little temperature drift. If pairs of gages are applied to opposite sides of an element, they can be wired so any remaining temperature effect from metal expansion cancels out. A full bridge of properly oriented strain gages should be almost totally insensitive to temperature.

Even temperature sensitivity can usually be calibrated out. I spent several years doing this at my last job. We calibrated sensors over a range of -40 to +70 C, often repeating calibrations every 10 C, and used a computer to compensate the measurements. Any good bee instrumentation setup will have a temperature measurement. If I still worked there and had access to the environmental chambers, I could have calibrated the temperature drift out of the cheap sensors.

I see no problem making a scale sensitive enough to measure a bee. The dynamics would be tough (the bee won't stand still), but I would bet you can do a pretty good job by taking a dynamic signal and running it thru a computer, maybe just averaging. Highway scales routinely weigh trucks moving across the scales at 40 mph. This is tricky but not impossible, and most A/D chips these days have built-in processors.

Dealing with rain, etc: Set up a dummy hive. Any shifts in its weight due to non-bee effects can be subtracted out of the other hives.


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