4 ms·

> using a cheap camera even if you had a RED Komodo feeding uncompressed 4K DCI 60fps video to a pci-express bus capture card, the sensor resolution and tiny s

> using a cheap camera even if you had a RED Komodo feeding uncompressed 4K DCI 60fps video to a pci-express bus capture card, the sensor resolution and tiny size of mosquitoes means that unless the lighting conditions are just right, and the mosquito is somehow highlighted against a background, it's going to be very hard to pick them out at distances of 2 or more meters. and that's before you get into the software problem of processing the fire hose of data that is 4096x2160 at 60fps raw. and the hardware cost of a very serious workstation class PC capable of taking the capture at 1:1 realtime. possibly a lidar based sensor or something might be more suitable to locating the x/y/z position of mosquitoes in a few meter area.

swayvil 6y ago
Would targeting the distinctive mosquito whine be feasible? You could have several bluetooth mikes scattered around the room for good triangulation
- danielheath 6y ago
  There’s a reason bats hunt by sonar instead of vision.
  - bigiain 6y ago
    To be fair though, part of that is because they hunt at night. There are a few places here in Sydney where you see a remarkable cloud of bats feeding in bright light - the lights over the harbour bridge and several of the tax buildings bordering the Botanic Gardens regularly have flocks of bats whirling around presumably attracted to all the insects flying in the bright lights...
    - danielheath 6y ago
      There's lots of food that only comes out at night; if it weren't bats, some other predator species would have developed sonar to hunt them.
- squarefoot 6y ago
  Audio would surely be the way to go, IMO, although I would avoid Bluetooth and generally any non essential digital transport both because of latency and possible compression artifacts. One could trick the mosquitoes into flying through a small restricted area in which wires wouldn't pose a problem by making it the only possible way to some bait for example, then setting mikes and traps in there.
- xxs 6y ago
  Bluetooth has too much latency, 50-100ms even quite optimistically. There are a lot better ways to have a custom solution.
- janoc 6y ago
  Or you could just spray RAID or something similar and kill all the mosquitoes there for pennies. No laser, no bluetooth, no microphones. And if you want to actually solve the mosquito issue, don't have standing water around. Or make sure fish and frogs can live in it. They love eating mosquito larvae. Not this boondoggle. Remember, engineering is also about realizing that the fact that you are able to do something doesn't always mean you should.
  - swayvil 6y ago
    it's a good point
agravier 6y ago
A LIDAR is not the right solution. A LIDAR misses most of the space a few meters away, and even if by chance the beam passes right over a mosquito, it will be filtered out by the built-in denoising algorithms.
samatman 6y ago
Mosquitos, as we all know, have a highly distinctive auditory signature. A phased microphone array is the only sensible approach to localized mosquito detection. It would probably work reasonably well. The problem is that the entire field is patent encumbered, because Myhrvold's company Intellectual Ventures has done some research on it, and no on in their right mind would go up against those guys.
- walrus01 6y ago
  Why am I absolutely not surprised that somebody with a background at Microsoft is an intellectual property patent squatter?
- westurner 6y ago
  Yeah, they already did sharks with lasers. IDK what the licensing terms are on that
  - walrus01 6y ago
    ONE MILLION DOLLARS
- silon42 6y ago
  Maybe some kind of audio resonance could be used to prevent then from flying or at least annoy them. It would probably be louder than desired, though, unless ultrasonic.
bigiain 6y ago
Hmmmm, I wonder... The paper claims "1 - 5mm" for a mosquito, which seems plausible. Lets pick 5mm out of pure optimism. The new(ism) HQ Raspberry Pi camera modules are 12megapixel ~4000x3000 pixel sensors, if you assume you could recognise a mosquito based on it's flight/movement pattern rather than needing to have an image of the mosquito, maybe having a 2x2 pixel resolution of it might be enough, so you could use an appropriate lens and cover a 5mm x 4000pixel / 2 = 10,000mm or 10m wide by 7.5m tall region. That seems totally do-able. Even up to 4x4 pixel per mosquito at 5m x 3.75m would happily cover the wall of my bedroom with the windows. You _might_ even be able to do that with the cheaper 8 megapixel V2 camera module instead of the HQ one. The background subtraction is fairly easy to do in OpenCV. Assuming there's not too much moving in the background (I might need to tie back my curtains?) I wonder if the path a mosquito traces out would be distinct enough to detect? Research (read "the first google hit) suggests mosquitos fly at 1.6-2.4kmh - call it 2 - which is just over half a meter per second, so about 20mm per frame at 25fps, or 8mm per frame at 60fps. If we choose to use the 4px = ~5mm numbers from above, that means if you detect a thing that might be a mosquito, you don't need to search very far around it in the subsequent frame to track it - if it's a mosquito, it's likely to be still there and within 6 or 7 px of where it was in the previous frame. (I've never tried doing this on something so small, but that technique works really well tracking people across multiple frames in a video. See: https://data-flair.training/blogs/python-project-real-time-human-detection-counting/ https://data-flair.training/blogs/python-project-real-time-h... ) I don't think that at least x,y detection of a mosquito in a 12 or 8 megapixel camera is impossible. The 8MP raspi camera has a 63deg horizontal field of view, so that 5m wide assumed view from earlier would be at 5m distance give or take. If you could get your shoot-down laser close enough to your detection camera, you might not need to care about the z axis. The camera module is about 20mm square - at 5m range shooting the laser across the edge of the camera module pcb might be "close enough"? Might not work at short range, though once you're close you could scan the bean around a bit, it'll be super obvious in the camera view when you've got a hit (assuming the background doesn't;t reflect the laser brighter that a lit up mosquito? Great, now I have an excuse to paint my walls with VantaBlack...) Another idea... Assume a similar setup - a camera aimed at a 5x3.75m cross section of space, with a line laser shining across it (one of those lasers shone through a cylinder that makes a line, like some power tools use to project guidelines). I'd guess it'd be possible (maybe even easy) to distinguish between dust mites and mosquitos lighting up as they cross the line laser? Perhaps have three co-planar line lasers 10mm or 20mm apart to make the timing of aiming your shoot-down laser easier, use the first flash as a detection signal and swivel your galvos to that region, and then use the 2nd/3rd flashes close by to quickly fine tune the aim without needing to swing too far? (Now I just need to work out which if any of my half finished projects I should stop working on and half finish this one... ;-) )

swayvil 6y ago

Would targeting the distinctive mosquito whine be feasible? You could have several bluetooth mikes scattered around the room for good triangulation

danielheath 6y ago
There’s a reason bats hunt by sonar instead of vision.
- bigiain 6y ago
  To be fair though, part of that is because they hunt at night. There are a few places here in Sydney where you see a remarkable cloud of bats feeding in bright light - the lights over the harbour bridge and several of the tax buildings bordering the Botanic Gardens regularly have flocks of bats whirling around presumably attracted to all the insects flying in the bright lights...
  - danielheath 6y ago
    There's lots of food that only comes out at night; if it weren't bats, some other predator species would have developed sonar to hunt them.
squarefoot 6y ago
Audio would surely be the way to go, IMO, although I would avoid Bluetooth and generally any non essential digital transport both because of latency and possible compression artifacts. One could trick the mosquitoes into flying through a small restricted area in which wires wouldn't pose a problem by making it the only possible way to some bait for example, then setting mikes and traps in there.
xxs 6y ago
Bluetooth has too much latency, 50-100ms even quite optimistically. There are a lot better ways to have a custom solution.
janoc 6y ago
Or you could just spray RAID or something similar and kill all the mosquitoes there for pennies. No laser, no bluetooth, no microphones. And if you want to actually solve the mosquito issue, don't have standing water around. Or make sure fish and frogs can live in it. They love eating mosquito larvae. Not this boondoggle. Remember, engineering is also about realizing that the fact that you are able to do something doesn't always mean you should.
- swayvil 6y ago
  it's a good point

agravier 6y ago

A LIDAR is not the right solution. A LIDAR misses most of the space a few meters away, and even if by chance the beam passes right over a mosquito, it will be filtered out by the built-in denoising algorithms.

samatman 6y ago

Mosquitos, as we all know, have a highly distinctive auditory signature. A phased microphone array is the only sensible approach to localized mosquito detection. It would probably work reasonably well. The problem is that the entire field is patent encumbered, because Myhrvold's company Intellectual Ventures has done some research on it, and no on in their right mind would go up against those guys.

walrus01 6y ago
Why am I absolutely not surprised that somebody with a background at Microsoft is an intellectual property patent squatter?
westurner 6y ago
Yeah, they already did sharks with lasers. IDK what the licensing terms are on that
- walrus01 6y ago
  ONE MILLION DOLLARS
silon42 6y ago
Maybe some kind of audio resonance could be used to prevent then from flying or at least annoy them. It would probably be louder than desired, though, unless ultrasonic.

bigiain 6y ago

Hmmmm, I wonder... The paper claims "1 - 5mm" for a mosquito, which seems plausible. Lets pick 5mm out of pure optimism. The new(ism) HQ Raspberry Pi camera modules are 12megapixel ~4000x3000 pixel sensors, if you assume you could recognise a mosquito based on it's flight/movement pattern rather than needing to have an image of the mosquito, maybe having a 2x2 pixel resolution of it might be enough, so you could use an appropriate lens and cover a 5mm x 4000pixel / 2 = 10,000mm or 10m wide by 7.5m tall region. That seems totally do-able. Even up to 4x4 pixel per mosquito at 5m x 3.75m would happily cover the wall of my bedroom with the windows. You _might_ even be able to do that with the cheaper 8 megapixel V2 camera module instead of the HQ one. The background subtraction is fairly easy to do in OpenCV. Assuming there's not too much moving in the background (I might need to tie back my curtains?) I wonder if the path a mosquito traces out would be distinct enough to detect? Research (read "the first google hit) suggests mosquitos fly at 1.6-2.4kmh - call it 2 - which is just over half a meter per second, so about 20mm per frame at 25fps, or 8mm per frame at 60fps. If we choose to use the 4px = ~5mm numbers from above, that means if you detect a thing that might be a mosquito, you don't need to search very far around it in the subsequent frame to track it - if it's a mosquito, it's likely to be still there and within 6 or 7 px of where it was in the previous frame. (I've never tried doing this on something so small, but that technique works really well tracking people across multiple frames in a video. See: https://data-flair.training/blogs/python-project-real-time-human-detection-counting/ https://data-flair.training/blogs/python-project-real-time-h... ) I don't think that at least x,y detection of a mosquito in a 12 or 8 megapixel camera is impossible. The 8MP raspi camera has a 63deg horizontal field of view, so that 5m wide assumed view from earlier would be at 5m distance give or take. If you could get your shoot-down laser close enough to your detection camera, you might not need to care about the z axis. The camera module is about 20mm square - at 5m range shooting the laser across the edge of the camera module pcb might be "close enough"? Might not work at short range, though once you're close you could scan the bean around a bit, it'll be super obvious in the camera view when you've got a hit (assuming the background doesn't;t reflect the laser brighter that a lit up mosquito? Great, now I have an excuse to paint my walls with VantaBlack...) Another idea... Assume a similar setup - a camera aimed at a 5x3.75m cross section of space, with a line laser shining across it (one of those lasers shone through a cylinder that makes a line, like some power tools use to project guidelines). I'd guess it'd be possible (maybe even easy) to distinguish between dust mites and mosquitos lighting up as they cross the line laser? Perhaps have three co-planar line lasers 10mm or 20mm apart to make the timing of aiming your shoot-down laser easier, use the first flash as a detection signal and swivel your galvos to that region, and then use the 2nd/3rd flashes close by to quickly fine tune the aim without needing to swing too far? (Now I just need to work out which if any of my half finished projects I should stop working on and half finish this one... ;-) )