17 ms·

22-Year-Old Lidar Whiz Claims Breakthrough

280 points by deepnotderp 9y ago

6stringmerc 9y ago
It will be interesting, to me, if there are any observable effects on nature exposed to 200 meter blasts of IR type wavelength stuff. I mean, maybe it'll scare off deer, or pull them in closer to see what's up? Any number of species with un-intended consequences. Insects in the desert. Pidgeons in the big city. Gulls on the coast. Maybe it's totally harmless, but I'd like a study that verifies mass adoption would not have ecological consequences.
- philipkglass 9y ago
  Your comment spurred me to search for information about near-infrared vision systems in animals. NIR vision appears to be entirely absent from vertebrates. (I am not claiming that it is present in invertebrates, only that I found stronger claims about absence from vertebrates.) See "The Verriest Lecture 2009: Recent progress in understanding mammalian color vision" https://pdfs.semanticscholar.org/c9df/0b61e4a45e10577c001513a4fc1432696b3c.pdf https://pdfs.semanticscholar.org/c9df/0b61e4a45e10577c001513... Particularly Figure 1. Vertebrate photopigment sensitivity drops off rapidly toward the near IR (~700 nm). I found this fascinating related (but not peer reviewed) document on arXiv, "Did Evolution get it right? An evaluation of near-infrared imaging in semantic scene segmentation" https://arxiv.org/pdf/1611.08815.pdf https://arxiv.org/pdf/1611.08815.pdf The author performs semantic segmentation with convnets using conventional visual-spectrum images and compares performance with images spectrally extended into the near-infrared. He finds that adding the additional NIR band did not improve task performance -- hence that evolution "got it right" by not expanding vision into a wavelength region that fails to improve semantic segmentation. I'm not sure how good this work is from a professional biologist's perspective, but I found it damn interesting. EDIT: note that this laser operating at 1550 nm is far from the long wave IR (~8000 nm and up) that various animals sense to detect prey body heat.
  - prestonbriggs 9y ago
    I believe that I can't see that wavelength, but the energy has to go somewhere (similarly, I can't see microwave radiation, but don't want to put my head in a running microwave, a la Infinite Jest). I think the better question is: Will it blind you/me/animals?
    - goodcanadian 9y ago
      Indeed, I find it mildly painful to look at IR emitters, for example, on a "night vision" security camera. I don't believe it is dangerous or will blind anyone, or anything, but it is plausible to me that there could be an unanticipated effect. EDIT: It appears that this is given a passing mention in the article: . . . it can receive at a wavelength of 1550 nanometers, deep in the infrared part of the spectrum. That makes this wavelength much safer for human eyes than today’s standard wavelength, 905 nm.
    - splawn 9y ago
      It depends on the power density. I have an IR laser that is invisible and it would burn your eyes out of your head.
      - hwillis 9y ago
        ~40 mW peak, ~10 nS pulses
    - hueving 9y ago
      >similarly, I can't see microwave radiation, but don't want to put my head in a running microwave, a la Infinite Jest Yet wireless access points spew microwave radiation at you all day.
      - p1esk 9y ago
        Not at 1,000W.
        9y ago
- hwillis 9y ago
  This wavelength of light is used for long range telecomms. We would know if it did anything. Animals can't see this wavelength, not even snakes or fish. In addition to that the laser spot is spread rapidly over a very wide area and it won't actually be visible except to extremely fast sensors, which eyes are not.
- chillydawg 9y ago
  Fish are sensitive to IR, it penetrates water better than visible or UV.
  - eric_h 9y ago
    > IR, it penetrates water better than visible or UV. What? IR is lower energy than visible red and that's the first color to go when you get a few feet under water (with no local light source).
    - dheera 9y ago
      Water does absorb infrared well but it's not because it has lower energy. Infrared is absorbed well due to the spectrum of vibrational transitions. Ultraviolet is also absorbed well, due to electronic transitions. There is a "window" in the visible light that is not absorbed well by many transitions.
      - eric_h 9y ago
        > but it's not because it has lower energy...There is a "window" in the visible light fair enough, I got my physics a bit wrong there, but I was under the impression that that window was in the blue/green part of the spectrum since I do know that water is good at blocking UV and even cosmic radiation. I also know that it's good at blocking visible red, because if you go further than about 20-30 feet down on a sunny day and cut yourself, your blood looks green. Is there an additional window in the infrared part of the spectrum that supports GP's point?
  - hwillis 9y ago
    some fish see some IR. Carp etc. would be able to see the 900 nm light in normal lidar, but even they can't see 1550 nm.
- AndrewKemendo 9y ago
  Considering ~55% of the sun's energy that hits the earth is in the form of IR, my guess is IR systems would be marginal. I think it bears testing though to be sure. As you say other creatures are much more sensitive to IR differences.
  - function_seven 9y ago
    That's a good point, but also reminds me of moths circling a flame or porch light. The vast majority of light we see in the world comes from the sun, but when the sun is elsewhere, our artificial light triggers changes in how insects behave. I wonder if ground-source lidar at night would have similar effects on animals that are "used to" IR coming from above.
- dheera 9y ago
  Deer cannot see at 1550 nm. I'm not aware of any mammals that can.
- agitator 9y ago
  This is a good point. But same goes for other sensors in cars. I always wondered how annoying AF ultra-sonic sensors are for dogs. It looks like most ultrasonic sensors are out of range for dogs, but the ultrasonics for sure mess with bats. I wonder how bat populations will be affected when all of these ultrasonic sensors mess with their ability to hunt.
  - fudged71 9y ago
    Cops in my city installed subsonic sirens on their cars to alert people who are playing loud music etc. Its always bothered me a bit about not knowing the potential impact to animals
  - hwillis 9y ago
    Ultrasound transducers are not the only producers of ultrasound, nor the loudest. Most things that vibrate create ultrasound, including almost anything that moves. Noise pollution is mostly produced accidentally. Also, nocturnal bats will largely be unaffected by cars in no small part because they don't cohabitate with humans very much.
- seanalltogether 9y ago
  1500nm is way outside the the range of usable solar radiation in nature. https://upload.wikimedia.org/wikipedia/commons/e/e7/Solar_spectrum_en.svg https://upload.wikimedia.org/wikipedia/commons/e/e7/Solar_sp... Snakes pick back up around 5000nm since that's the temperature other living animals radiate, which is helpful in hunting. https://en.wikipedia.org/wiki/Infrared_sensing_in_snakes https://en.wikipedia.org/wiki/Infrared_sensing_in_snakes
- grizzles 9y ago
  I don't know about IR but Kestrel's (the bird) are UV sensitive. AFAIK all organics emit IR so it's probably not going to be a problem.
- red75prime 9y ago
  Can I direct your attention to the street lights? Those death traps, causing millions of insects to fly in circles and possibly die of exhaustion. You will save many more insects, raising awareness to this problem.
  - rijoja 9y ago
    Exactly we are blasting so much radiation everywhere, why should we start caring now with the IR radiation.
    - Crespyl 9y ago
      The best way to start fixing a problem is to stop making things worse. LIDAR may or may not have an adverse impact on wildlife, but we should at least find out and see if there are simple ways to mitigate any possible side effects.
- simonh 9y ago
  Many types of common headlights, and other light sources, emit tons of IR radiation already so we'd probably know.
- joshvm 9y ago
  What you care about is the maximum permissible exposure at close range - because it's entirely possible that a kid is going to walk up to your car and stick their face up against the glass. The laser beam will already be fairly wide (order of mm) as it exists the system, but it needs to be reasonably low divergence to give you accurate spatial information 200 m away. We should assume to be pessimistic, that you get the full beam into your eye (up to 7 mm). This is really back of the envelope stuff, but there are lots of factors to consider. You could probably get away with even a 100mW laser with the right setup. Obvious disclaimer that you should respect laser safety and not trust someone's internet napkin calculations. According to this you're allowed 1W/m^2 at > 1400nm for an accidental exposure (100 seconds): https://workspace.imperial.ac.uk/physics/Public/physicsdocs/about/safety/files/MPE-tables.pdf https://workspace.imperial.ac.uk/physics/Public/physicsdocs/... Equivalently that's 1 mW/mm^2. So the question is, what power is the laser kicking out? A Faro scanner can put out as much as 20mW/mm^2 at 1m and their systems are thus Class 3R. So far, so bad. However... laser safety ratings are given as "Under normal operating conditions". The laser is being scanned, and very quickly at that, so you'd only be getting very short bursts of light (I don't know if it's truly a pulsed laser). If you stared into the beam continuously you would have problems, but since the beam is only going to hit you for a fraction of a second it's unlikely to do any damage. And indeed Faro say that for practical purposes their system is eye-safe, even though it's got a stonking laser in it. The tables say you can go up to 10^4 J/m^2 for short exposures and suppose we only have the beam in our eye for 10^-3 seconds (additionally the pulse length will be very short), you're allowed a light power of perhaps 1000 times higher. Maybe divide by a factor of 100 or so because you'd get several repeat exposures if you stood in the same place or if you're standing on a street filled with these things. Have a look at Faro's manual, Appendix E for a real example of this kind of analysis: https://doarch332.files.wordpress.com/2013/11/e866_faro_laser_scanner_focus3d_manual_en.pdf https://doarch332.files.wordpress.com/2013/11/e866_faro_lase...
tyingq 9y ago
The actual candor around the limitations, from a potential beneficiary of the Lidar boom, is refreshing.
- jobu 9y ago
  My thoughts exactly. Issues with rain/snow are a common concern, but I had never heard of the "dark car problem" : Current lidar systems can’t see a black tire, or a person like me wearing black—Velodyne’s [Puck] wouldn’t see a 5- to 10-percent reflective object [30 meters away]. It’s the dark car problem—no one else talks about it!”
  - macintux 9y ago
    Considering nearly every pedestrian walking along the streets near me at night is wearing dark clothes (and there are typically no sidewalks) that's a terrifying statement.
    - hwillis 9y ago
      It's not a problem at night. It's a problem during the day, when everything is washed out. The lidar can still see something there, but not how far away it is.
      - macintux 9y ago
        Ok. Still not remotely good.
        hwillis 9y ago
        Note that it's a matte black car problem. Shiny black cars are visible. It's also not a problem at short distances, or if there are significant parts of the car that are visible. It's a similar thing to not being able to see men carrying a glass windowpane. It's a somewhat niche problem.
        9y ago
deepnotderp 9y ago
It's interesting that he uses InGaAs, that's a relatively expensive material and closes off the possibility of silicon photonics.
- spott 9y ago
  Not necessarily. Bonding III/V materials onto Silicon is a thing[0]. Not to say it would be easy, but it should be doable. [0]https://optoelectronics.ece.ucsb.edu/sites/default/files/2017-02/Davenport%20Heterogeneous%20Silicon%20III–V%20Semiconductor%20Optical%20Amplifiers_0.pdf https://optoelectronics.ece.ucsb.edu/sites/default/files/201...
givemefive 9y ago
There's a video here: https://www.youtube.com/watch?v=AasQG3fR8Mo https://www.youtube.com/watch?v=AasQG3fR8Mo
Hasz 9y ago
Maybe I missed it, but I see no actual power output, just multiples of some standard. IS this thing putting out 5mW or 1W?
- hwillis 9y ago
  probably tens of milliwatts, normal lidars are fractions of a milliwatt average output. The HDL-64 has a max laser power of 1mW.
c517402 9y ago
Back when the only really powerful lasers that could be found for optical tables were IR, I know a couple of guys who lost enough of their retina to be considered legally blind from light they couldn't see. One of them told me, "You know you're in trouble when your eye starts to hurt and you realize your safety glasses aren't on."
- Kenji 9y ago
  As someone who works with lasers on a daily basis - this is my nightmare. Luckily they're almost always overlaid with visible light (except during some special production steps), making things much safer.
- Confusion 9y ago
  They wouldn't be in that trouble if their quote was shorter: "You know you're in trouble when ... your safety glasses aren't on."
deleted 9y ago
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partisan 9y ago
I wonder if this is a problem that can be solved by public-private partnerships. What if we have a public utility that maintains a network of cameras throughout the city that can be used to create a real-time self driving guidance system. Users of the system would pay fees to patch into the data feed so that their cars can use that data. The utility would turn the data into anonymized object data. Since we would want to have standards around this type of infrastructure data, it would be regulated in the early days and then can move to deregulation where third party providers can layer other data and analysis into the stream. This could be cheaper and more effective than the current attempts at per-car LIDAR with all of its limitations. Alternatively, you could aggregate the data collected by all of the cars and provide a single vision of the local area that is not limited by your single LIDAR unit.
- Fjolsvith 9y ago
  Think of the nightmare situations if that infrastructure data was hacked...
  - jopsen 9y ago
    As oppose to all the car companies having the data? You don't think the car companies won't record, collect and analyse the data for advertisement purposes?
    - maxerickson 9y ago
      That's why telematics are already in most new vehicles. Chevrolet wants to be a data company. https://www.bloomberg.com/news/articles/2016-07-12/your-car-s-been-studying-you-closely-and-everyone-wants-the-data https://www.bloomberg.com/news/articles/2016-07-12/your-car-...
  - indolering 9y ago
    In the US, most local Governments capable of rolling out such infrastructure already record everything a lot of information. Seattle public transit records everything (including audio!). Many have license plate scanners in busy streets. Then they have a roving band of police who with dash and body cameras.
deepnet 9y ago
What is the output of LIDAR ? A point cloud or stripes ? What are the specs of the output of a LIDAR such a Velodyne or this one ?
- nix0n 9y ago
  Generally LIDAR outputs a point cloud. Velodynes tend to output very stripey point clouds. Edit to add more info: the Puck's data sheet [0] claims a range of 100m and 300,000 points per second. [0] http://velodynelidar.com/docs/datasheet/63-9229_Rev-F_Puck%20_Spec%20Sheet_Web.pdf http://velodynelidar.com/docs/datasheet/63-9229_Rev-F_Puck%2...
- timdorr 9y ago
  The front page video on their site gives a good visual on their output: https://www.luminartech.com https://www.luminartech.com The rainbow colors are, of course, optional.
- joshvm 9y ago
  It's a point cloud, but you get stripes because of the way the systems scan. Unless you're using a flash LIDAR (mucho dinero), all LIDAR are single point sensors which have to be scanned. That is, you send out a pulse of light and a single photodiode detects the return signal. A Velodyne LIDAR has up to 64 rx/tx pairs arranged into a grid which is rotated rapidly, so you end up imaging a series of rings around the sensor. Specs - the best LIDAR systems scan at around 1Mpt/second over a full hemisphere. The Velodyne system gives you around 20-30k measurements in the field of view a typical car camera. Accuracy is centimeter level. Stripes are produced by laser triangulation systems, but they're not true LIDAR. You project a line and look at how the image of it shifts compared to a known distance.
lerie 9y ago
The article is unbearable to read.
- cowardlydragon 9y ago
  agreed
Lord_Zero 9y ago
This website is really frustrating to use.
- 0xCMP 9y ago
  It's fine if all JS is disabled using uMatrix
iaw 9y ago
I wonder how the tradeoff between precision, speed of movement, and robustness of the system was handled. Will a moving car on a bumpy road suffer from corrupted signals?
Sephr 9y ago
Just because I can't see infrared doesn't mean it won't damage my retinas through my fully dilated pupils at night when you pump up the power by 40x. Edit: Emphasis on fully dilated. The amount of infrared energy that reaches my retinas in daylight is reduced due to pupil contraction. Additionally, this has moving parts so what if it suddenly fails to spin and you are exposed to a continuous IR beam with fully dilated pupils at night? I'm sure that it's possible for it to heat and damage your retina in this failure scenario.
- IanCal 9y ago
  No, it doesn't just mean that. But it's rather a quick judgement to suggest that's their line of thinking. It may well be fine to do this if increasing the wavelength to over 900nm makes a beam far less damaging. A more useful comment would be to ask what the wavelength-damage relationship is for different power levels.
  - deleted 9y ago
    [deleted]
- hwillis 9y ago
  Nah, you'll be fine. You receive a couple hundred watts of near infrared radiation (ie the 1550 nm in the laser) just by being in direct sunlight. That's spread over your entire body, of course. The laser in this lidar has a power of ~40 mW, which technically puts it out of being a class 1[1] laser, ie you can shine it directly into your pupil through a magnifying glass without fear. However the class is just a guideline. Using a maximum permissible exposure chart gives a better sense of danger. Lidar pulses are on the order of 10 nanoseconds, or 1/100th the smallest division on this chart[2]. Even so, you can see that the maximum safe power for 1550 nm is somewhere between 8 and 10,000 watts, at least 800x more than the lidar emits. 1550 nm doesn't chemically damage biological receptors. The damage would have to be thermal, but the laser is pulsed for an incredibly short time and even if it wasn't it's well under what you can be exposed to indefinitely. [1] https://en.wikipedia.org/wiki/Laser_safety#/media/File:Laser_class_EN_60825-1.en.png https://en.wikipedia.org/wiki/Laser_safety#/media/File:Laser... [2] https://en.wikipedia.org/wiki/File:IEC60825_MPE_W_s.png https://en.wikipedia.org/wiki/File:IEC60825_MPE_W_s.png
spuz 9y ago
It's interesting that the perspective in this article is that the high price is unimportant. Isn't the problem with existing spinning mirror Lidar that it's expensive? It makes me think there is some other advantage that solid state Lidars have to generate so much investment.
- abakker 9y ago
  Also that it is relatively fragile. It is one thing to have expensive precisions instruments, but in cars, they need to be able take the bumps, shakes and any other forces that the car takes. That can be tough on tiny bearings with low intended duty cycles. Of course, you can beef up all of that to make it last, but if you avoid mechanical components all together it is definitely better.
  - sliken 9y ago
    Plenty of moving parts in a car, but the vast majority of them are metal and most with pretty forgiving tolerances. Fast spinning mirrors aren't particularly hard, but the tolerances are pretty unforgiving. Being able to tell if a car is partially in your lane at 200 meters is a pretty small angle. Cars take quite a bit of abuse over their 100-200k mile lifetime. Vibration (at numerous frequencies), huge temperature variations (120F to -20F or so). Not sure I buy that Lidar is better than cameras for cars. Especially since they are cheap enough for you to have a dozen of them. Better price point, and more likely to have the same limitations as eyes do (to fit social expectations). Sadly society seems more focused on failures than a strict rational decision of deciding if a technology is worthwhile based on the numbers of lives saved vs lost. Sure, if someone can make a solid state lidar using the lower frequency light (so they can use 40x stronger laser) it might compete. I'd still worry about blind spots because of fog, smog, snow, sleet, rain, blowing dust, sand storms, etc.
- joshvm 9y ago
  Moving parts and economy of scale. If you want to buy an industrial 1D LIDAR off the shelf today, you're looking at a few thousand dollars. A galvanometer scanner like these guys use is again, several thousand dollars (just look at Thorlabs for a basic system). InGaS array sensors are also not cheap. Frankly I'm skeptical that a galvo based system will last long in the real world. In principle, flash LIDAR solves all of the problems. You can image an area at long distance in real-time. It has no moving parts and it's presumably amenable to MEMS production. Basic (non-MEMS) units from people like ASC cost tens of thousands. We just need someone with a serious bankroll to develop one. We saw exactly the same with Time of Flight cameras. Microsoft bought Canesta and suddenly a $5k+ camera cost $100.
joshvm 9y ago
So it's a LIDAR + galvanometer scanner in a box? This is nothing particularly novel in itself, except they seem to have solved the scanning-speed problem. If you look at the videos of the scan, you can see that rather than the ring-like scans you'd get from a Velodyne system, you get a kind of snake-path. They're scanning (extremely quickly, by the looks of it) with a mirror and doing a kind of raster pattern. From a skim of their patent it's a multiplexed system - http://www.freepatentsonline.com/y2017/0131388.html http://www.freepatentsonline.com/y2017/0131388.html Seems like they're using a galvo to scan the LIDAR and they're beamsplitting the laser to get multiple returns.
- indolering 9y ago
  > except they seem to have solved the scanning-speed problem By way of a GaN chip, which is the standard solution for anything requiring super high clock speeds. Considering another company is pitching a $50 solid-state LIDAR for autonomous vehicles, I don't think this qualifies as a breakthrough[0]. It's just the market pushing prices down. [1]: http://spectrum.ieee.org/cars-that-think/transportation/sensors/osrams-laser-chip-for-lidar-promises-supershort-pulses-in-a-smaller-package http://spectrum.ieee.org/cars-that-think/transportation/sens...
  - joshvm 9y ago
    I was thinking more of the mirrors. I've used galvo systems at work before, and the off the shelf ones couldn't come close to the sorts of speeds they're showing off. Especially not in a raster pattern. 3D LIDAR using galvos has been done before for space applications (one was used on the space shuttle, or at least a ground-based model), they used a lissajous scanning pattern which is much kinder on the motors because you can do continuous movements rather than making the mirror do a rapid turn at the end of each row. It's called TriDAR: http://adsabs.harvard.edu/abs/2006SPIE.6220E...7R http://adsabs.harvard.edu/abs/2006SPIE.6220E...7R
smoyer 9y ago
As a cautionary warning, a laser with a 1550 nm wavelength can still cause damage to the human eye. I don't know how collimated the laser in this system is but when we piped this color of light down single-mode fiber, looking in the other end could leave you with a dead spot in your retina.
- rubidium 9y ago
  They said in the article it was low mW. Yes, looking at the other end of a laser fiber is stupid, particularly when your eye can't see the wavelength. If you're working with 1550nm light and single-mode fibers you should know that, and if you don't you should've received better laser safety training.
51Cards 9y ago
Can someone clarify this: "...particularly at 200 meters and beyond. That’s how far cars will have to see at highway speeds if they want to give themselves more than half a second to react to events." 200 meters, half second? That would mean the car is covering 1km in 2.5 seconds, or 1440km/h. Not sure what type of car is going that fast.
- mahyarm 9y ago
  Processing lag probably contributes
- dtparr 9y ago
  My reading is that the half second only accounts for reaction time, not stopping distance. Two cars head on at highway speeds would barely be able to stop from a 200m detection.
- nathan-muir 9y ago
  I think the author is slightly exaggerating here; not that the larger range wouldn't be useful. Assuming that there's a stationary obstruction that you must come to a complete stop. According to [1] the stopping distance of a car travelling at 70mph is 245ft (75m). A car travelling at 70mph is doing approx 31m/s. With a 0.5s reaction time, the car would travel only 90m, or; With a 200m range, the car would have 4s to initiate an emergency breaking manoeuvre. [1] http://www.government-fleet.com/content/driver-care-know-your-stopping-distance.aspx http://www.government-fleet.com/content/driver-care-know-you...
bitmapbrother 9y ago
>But, because it hasn’t got the 360-degree coverage of a rooftop tower, you’d need four units, one for each corner of the car. The technology is certainly interesting and it does have its advantages, but the need to use 4 of these units, for complete coverage, isn't exactly going to make it cheap.
theprop 9y ago
You can be super-human with just cameras. Lidar is not required.
ptero 9y ago
Pencil beam with fast scans coupled to a moving, unstabilized platform can introduce stitching/alignment problems that must be solved to maintain high accuracy. I wonder how well this system does it -- it is not trivial.
jpitz 9y ago
The article mentions that the primary advantage of this approach is that it provides the long distance coverage necessary to handle highway speeds. It also states that, because of the device design, you'd need 4, one at each corner. It seems to me that you don't need 200m coverage to the rear, and maybe the rear of the vehicle could be handled by a less expensive 360-degree lidar unit?
- deleted 9y ago
  [deleted]
bogomipz 9y ago
The article states: “Current lidar systems can’t see a black tire, or a person like me wearing black—Velodyne’s [Puck] wouldn’t see a 5- to 10-percent reflective object [30 meters away]. It’s the dark car problem—no one else talks about it!” How are the current autonomous vehicles from the Google, Uber et al compensating for this shortcoming? If anyone has some recommendations for learning more about Lidar that they could share I appreciate it.
- babo 9y ago
  Using more than one sensor helps, radar could see a black car, while lidar not.

280 points by deepnotderp 9y ago

It will be interesting, to me, if there are any observable effects on nature exposed to 200 meter blasts of IR type wavelength stuff. I mean, maybe it'll scare off deer, or pull them in closer to see what's up? Any number of species with un-intended consequences. Insects in the desert. Pidgeons in the big city. Gulls on the coast. Maybe it's totally harmless, but I'd like a study that verifies mass adoption would not have ecological consequences.

philipkglass 9y ago
Your comment spurred me to search for information about near-infrared vision systems in animals. NIR vision appears to be entirely absent from vertebrates. (I am not claiming that it is present in invertebrates, only that I found stronger claims about absence from vertebrates.) See "The Verriest Lecture 2009: Recent progress in understanding mammalian color vision" https://pdfs.semanticscholar.org/c9df/0b61e4a45e10577c001513a4fc1432696b3c.pdf https://pdfs.semanticscholar.org/c9df/0b61e4a45e10577c001513... Particularly Figure 1. Vertebrate photopigment sensitivity drops off rapidly toward the near IR (~700 nm). I found this fascinating related (but not peer reviewed) document on arXiv, "Did Evolution get it right? An evaluation of near-infrared imaging in semantic scene segmentation" https://arxiv.org/pdf/1611.08815.pdf https://arxiv.org/pdf/1611.08815.pdf The author performs semantic segmentation with convnets using conventional visual-spectrum images and compares performance with images spectrally extended into the near-infrared. He finds that adding the additional NIR band did not improve task performance -- hence that evolution "got it right" by not expanding vision into a wavelength region that fails to improve semantic segmentation. I'm not sure how good this work is from a professional biologist's perspective, but I found it damn interesting. EDIT: note that this laser operating at 1550 nm is far from the long wave IR (~8000 nm and up) that various animals sense to detect prey body heat.
- prestonbriggs 9y ago
  I believe that I can't see that wavelength, but the energy has to go somewhere (similarly, I can't see microwave radiation, but don't want to put my head in a running microwave, a la Infinite Jest). I think the better question is: Will it blind you/me/animals?
  - goodcanadian 9y ago
    Indeed, I find it mildly painful to look at IR emitters, for example, on a "night vision" security camera. I don't believe it is dangerous or will blind anyone, or anything, but it is plausible to me that there could be an unanticipated effect. EDIT: It appears that this is given a passing mention in the article: . . . it can receive at a wavelength of 1550 nanometers, deep in the infrared part of the spectrum. That makes this wavelength much safer for human eyes than today’s standard wavelength, 905 nm.
  - splawn 9y ago
    It depends on the power density. I have an IR laser that is invisible and it would burn your eyes out of your head.
    - hwillis 9y ago
      ~40 mW peak, ~10 nS pulses
  - hueving 9y ago
    >similarly, I can't see microwave radiation, but don't want to put my head in a running microwave, a la Infinite Jest Yet wireless access points spew microwave radiation at you all day.
    - p1esk 9y ago
      Not at 1,000W.
      - 9y ago
hwillis 9y ago
This wavelength of light is used for long range telecomms. We would know if it did anything. Animals can't see this wavelength, not even snakes or fish. In addition to that the laser spot is spread rapidly over a very wide area and it won't actually be visible except to extremely fast sensors, which eyes are not.
chillydawg 9y ago
Fish are sensitive to IR, it penetrates water better than visible or UV.
- eric_h 9y ago
  > IR, it penetrates water better than visible or UV. What? IR is lower energy than visible red and that's the first color to go when you get a few feet under water (with no local light source).
  - dheera 9y ago
    Water does absorb infrared well but it's not because it has lower energy. Infrared is absorbed well due to the spectrum of vibrational transitions. Ultraviolet is also absorbed well, due to electronic transitions. There is a "window" in the visible light that is not absorbed well by many transitions.
    - eric_h 9y ago
      > but it's not because it has lower energy...There is a "window" in the visible light fair enough, I got my physics a bit wrong there, but I was under the impression that that window was in the blue/green part of the spectrum since I do know that water is good at blocking UV and even cosmic radiation. I also know that it's good at blocking visible red, because if you go further than about 20-30 feet down on a sunny day and cut yourself, your blood looks green. Is there an additional window in the infrared part of the spectrum that supports GP's point?
- hwillis 9y ago
  some fish see some IR. Carp etc. would be able to see the 900 nm light in normal lidar, but even they can't see 1550 nm.
AndrewKemendo 9y ago
Considering ~55% of the sun's energy that hits the earth is in the form of IR, my guess is IR systems would be marginal. I think it bears testing though to be sure. As you say other creatures are much more sensitive to IR differences.
- function_seven 9y ago
  That's a good point, but also reminds me of moths circling a flame or porch light. The vast majority of light we see in the world comes from the sun, but when the sun is elsewhere, our artificial light triggers changes in how insects behave. I wonder if ground-source lidar at night would have similar effects on animals that are "used to" IR coming from above.
dheera 9y ago
Deer cannot see at 1550 nm. I'm not aware of any mammals that can.
agitator 9y ago
This is a good point. But same goes for other sensors in cars. I always wondered how annoying AF ultra-sonic sensors are for dogs. It looks like most ultrasonic sensors are out of range for dogs, but the ultrasonics for sure mess with bats. I wonder how bat populations will be affected when all of these ultrasonic sensors mess with their ability to hunt.
- fudged71 9y ago
  Cops in my city installed subsonic sirens on their cars to alert people who are playing loud music etc. Its always bothered me a bit about not knowing the potential impact to animals
- hwillis 9y ago
  Ultrasound transducers are not the only producers of ultrasound, nor the loudest. Most things that vibrate create ultrasound, including almost anything that moves. Noise pollution is mostly produced accidentally. Also, nocturnal bats will largely be unaffected by cars in no small part because they don't cohabitate with humans very much.
seanalltogether 9y ago
1500nm is way outside the the range of usable solar radiation in nature. https://upload.wikimedia.org/wikipedia/commons/e/e7/Solar_spectrum_en.svg https://upload.wikimedia.org/wikipedia/commons/e/e7/Solar_sp... Snakes pick back up around 5000nm since that's the temperature other living animals radiate, which is helpful in hunting. https://en.wikipedia.org/wiki/Infrared_sensing_in_snakes https://en.wikipedia.org/wiki/Infrared_sensing_in_snakes
grizzles 9y ago
I don't know about IR but Kestrel's (the bird) are UV sensitive. AFAIK all organics emit IR so it's probably not going to be a problem.
red75prime 9y ago
Can I direct your attention to the street lights? Those death traps, causing millions of insects to fly in circles and possibly die of exhaustion. You will save many more insects, raising awareness to this problem.
- rijoja 9y ago
  Exactly we are blasting so much radiation everywhere, why should we start caring now with the IR radiation.
  - Crespyl 9y ago
    The best way to start fixing a problem is to stop making things worse. LIDAR may or may not have an adverse impact on wildlife, but we should at least find out and see if there are simple ways to mitigate any possible side effects.
simonh 9y ago
Many types of common headlights, and other light sources, emit tons of IR radiation already so we'd probably know.
joshvm 9y ago
What you care about is the maximum permissible exposure at close range - because it's entirely possible that a kid is going to walk up to your car and stick their face up against the glass. The laser beam will already be fairly wide (order of mm) as it exists the system, but it needs to be reasonably low divergence to give you accurate spatial information 200 m away. We should assume to be pessimistic, that you get the full beam into your eye (up to 7 mm). This is really back of the envelope stuff, but there are lots of factors to consider. You could probably get away with even a 100mW laser with the right setup. Obvious disclaimer that you should respect laser safety and not trust someone's internet napkin calculations. According to this you're allowed 1W/m^2 at > 1400nm for an accidental exposure (100 seconds): https://workspace.imperial.ac.uk/physics/Public/physicsdocs/about/safety/files/MPE-tables.pdf https://workspace.imperial.ac.uk/physics/Public/physicsdocs/... Equivalently that's 1 mW/mm^2. So the question is, what power is the laser kicking out? A Faro scanner can put out as much as 20mW/mm^2 at 1m and their systems are thus Class 3R. So far, so bad. However... laser safety ratings are given as "Under normal operating conditions". The laser is being scanned, and very quickly at that, so you'd only be getting very short bursts of light (I don't know if it's truly a pulsed laser). If you stared into the beam continuously you would have problems, but since the beam is only going to hit you for a fraction of a second it's unlikely to do any damage. And indeed Faro say that for practical purposes their system is eye-safe, even though it's got a stonking laser in it. The tables say you can go up to 10^4 J/m^2 for short exposures and suppose we only have the beam in our eye for 10^-3 seconds (additionally the pulse length will be very short), you're allowed a light power of perhaps 1000 times higher. Maybe divide by a factor of 100 or so because you'd get several repeat exposures if you stood in the same place or if you're standing on a street filled with these things. Have a look at Faro's manual, Appendix E for a real example of this kind of analysis: https://doarch332.files.wordpress.com/2013/11/e866_faro_laser_scanner_focus3d_manual_en.pdf https://doarch332.files.wordpress.com/2013/11/e866_faro_lase...

tyingq 9y ago

The actual candor around the limitations, from a potential beneficiary of the Lidar boom, is refreshing.

jobu 9y ago
My thoughts exactly. Issues with rain/snow are a common concern, but I had never heard of the "dark car problem" : Current lidar systems can’t see a black tire, or a person like me wearing black—Velodyne’s [Puck] wouldn’t see a 5- to 10-percent reflective object [30 meters away]. It’s the dark car problem—no one else talks about it!”
- macintux 9y ago
  Considering nearly every pedestrian walking along the streets near me at night is wearing dark clothes (and there are typically no sidewalks) that's a terrifying statement.
  - hwillis 9y ago
    It's not a problem at night. It's a problem during the day, when everything is washed out. The lidar can still see something there, but not how far away it is.
    - macintux 9y ago
      Ok. Still not remotely good.
      - hwillis 9y ago
        Note that it's a matte black car problem. Shiny black cars are visible. It's also not a problem at short distances, or if there are significant parts of the car that are visible. It's a similar thing to not being able to see men carrying a glass windowpane. It's a somewhat niche problem.
        9y ago

deepnotderp 9y ago

It's interesting that he uses InGaAs, that's a relatively expensive material and closes off the possibility of silicon photonics.

spott 9y ago
Not necessarily. Bonding III/V materials onto Silicon is a thing[0]. Not to say it would be easy, but it should be doable. [0]https://optoelectronics.ece.ucsb.edu/sites/default/files/2017-02/Davenport%20Heterogeneous%20Silicon%20III–V%20Semiconductor%20Optical%20Amplifiers_0.pdf https://optoelectronics.ece.ucsb.edu/sites/default/files/201...

givemefive 9y ago

There's a video here: https://www.youtube.com/watch?v=AasQG3fR8Mo https://www.youtube.com/watch?v=AasQG3fR8Mo

Hasz 9y ago

Maybe I missed it, but I see no actual power output, just multiples of some standard. IS this thing putting out 5mW or 1W?

hwillis 9y ago
probably tens of milliwatts, normal lidars are fractions of a milliwatt average output. The HDL-64 has a max laser power of 1mW.

c517402 9y ago

Back when the only really powerful lasers that could be found for optical tables were IR, I know a couple of guys who lost enough of their retina to be considered legally blind from light they couldn't see. One of them told me, "You know you're in trouble when your eye starts to hurt and you realize your safety glasses aren't on."

Kenji 9y ago
As someone who works with lasers on a daily basis - this is my nightmare. Luckily they're almost always overlaid with visible light (except during some special production steps), making things much safer.
Confusion 9y ago
They wouldn't be in that trouble if their quote was shorter: "You know you're in trouble when ... your safety glasses aren't on."

deleted 9y ago

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partisan 9y ago

I wonder if this is a problem that can be solved by public-private partnerships. What if we have a public utility that maintains a network of cameras throughout the city that can be used to create a real-time self driving guidance system. Users of the system would pay fees to patch into the data feed so that their cars can use that data. The utility would turn the data into anonymized object data. Since we would want to have standards around this type of infrastructure data, it would be regulated in the early days and then can move to deregulation where third party providers can layer other data and analysis into the stream. This could be cheaper and more effective than the current attempts at per-car LIDAR with all of its limitations. Alternatively, you could aggregate the data collected by all of the cars and provide a single vision of the local area that is not limited by your single LIDAR unit.

Fjolsvith 9y ago
Think of the nightmare situations if that infrastructure data was hacked...
- jopsen 9y ago
  As oppose to all the car companies having the data? You don't think the car companies won't record, collect and analyse the data for advertisement purposes?
  - maxerickson 9y ago
    That's why telematics are already in most new vehicles. Chevrolet wants to be a data company. https://www.bloomberg.com/news/articles/2016-07-12/your-car-s-been-studying-you-closely-and-everyone-wants-the-data https://www.bloomberg.com/news/articles/2016-07-12/your-car-...
- indolering 9y ago
  In the US, most local Governments capable of rolling out such infrastructure already record everything a lot of information. Seattle public transit records everything (including audio!). Many have license plate scanners in busy streets. Then they have a roving band of police who with dash and body cameras.

deepnet 9y ago

What is the output of LIDAR ? A point cloud or stripes ? What are the specs of the output of a LIDAR such a Velodyne or this one ?

nix0n 9y ago
Generally LIDAR outputs a point cloud. Velodynes tend to output very stripey point clouds. Edit to add more info: the Puck's data sheet [0] claims a range of 100m and 300,000 points per second. [0] http://velodynelidar.com/docs/datasheet/63-9229_Rev-F_Puck%20_Spec%20Sheet_Web.pdf http://velodynelidar.com/docs/datasheet/63-9229_Rev-F_Puck%2...
timdorr 9y ago
The front page video on their site gives a good visual on their output: https://www.luminartech.com https://www.luminartech.com The rainbow colors are, of course, optional.
joshvm 9y ago
It's a point cloud, but you get stripes because of the way the systems scan. Unless you're using a flash LIDAR (mucho dinero), all LIDAR are single point sensors which have to be scanned. That is, you send out a pulse of light and a single photodiode detects the return signal. A Velodyne LIDAR has up to 64 rx/tx pairs arranged into a grid which is rotated rapidly, so you end up imaging a series of rings around the sensor. Specs - the best LIDAR systems scan at around 1Mpt/second over a full hemisphere. The Velodyne system gives you around 20-30k measurements in the field of view a typical car camera. Accuracy is centimeter level. Stripes are produced by laser triangulation systems, but they're not true LIDAR. You project a line and look at how the image of it shifts compared to a known distance.

lerie 9y ago

The article is unbearable to read.

cowardlydragon 9y ago
agreed

Lord_Zero 9y ago

This website is really frustrating to use.

0xCMP 9y ago
It's fine if all JS is disabled using uMatrix

iaw 9y ago

I wonder how the tradeoff between precision, speed of movement, and robustness of the system was handled. Will a moving car on a bumpy road suffer from corrupted signals?

Sephr 9y ago

Just because I can't see infrared doesn't mean it won't damage my retinas through my fully dilated pupils at night when you pump up the power by 40x. Edit: Emphasis on fully dilated. The amount of infrared energy that reaches my retinas in daylight is reduced due to pupil contraction. Additionally, this has moving parts so what if it suddenly fails to spin and you are exposed to a continuous IR beam with fully dilated pupils at night? I'm sure that it's possible for it to heat and damage your retina in this failure scenario.

IanCal 9y ago
No, it doesn't just mean that. But it's rather a quick judgement to suggest that's their line of thinking. It may well be fine to do this if increasing the wavelength to over 900nm makes a beam far less damaging. A more useful comment would be to ask what the wavelength-damage relationship is for different power levels.
- deleted 9y ago
  [deleted]
hwillis 9y ago
Nah, you'll be fine. You receive a couple hundred watts of near infrared radiation (ie the 1550 nm in the laser) just by being in direct sunlight. That's spread over your entire body, of course. The laser in this lidar has a power of ~40 mW, which technically puts it out of being a class 1[1] laser, ie you can shine it directly into your pupil through a magnifying glass without fear. However the class is just a guideline. Using a maximum permissible exposure chart gives a better sense of danger. Lidar pulses are on the order of 10 nanoseconds, or 1/100th the smallest division on this chart[2]. Even so, you can see that the maximum safe power for 1550 nm is somewhere between 8 and 10,000 watts, at least 800x more than the lidar emits. 1550 nm doesn't chemically damage biological receptors. The damage would have to be thermal, but the laser is pulsed for an incredibly short time and even if it wasn't it's well under what you can be exposed to indefinitely. [1] https://en.wikipedia.org/wiki/Laser_safety#/media/File:Laser_class_EN_60825-1.en.png https://en.wikipedia.org/wiki/Laser_safety#/media/File:Laser... [2] https://en.wikipedia.org/wiki/File:IEC60825_MPE_W_s.png https://en.wikipedia.org/wiki/File:IEC60825_MPE_W_s.png

spuz 9y ago

It's interesting that the perspective in this article is that the high price is unimportant. Isn't the problem with existing spinning mirror Lidar that it's expensive? It makes me think there is some other advantage that solid state Lidars have to generate so much investment.

abakker 9y ago
Also that it is relatively fragile. It is one thing to have expensive precisions instruments, but in cars, they need to be able take the bumps, shakes and any other forces that the car takes. That can be tough on tiny bearings with low intended duty cycles. Of course, you can beef up all of that to make it last, but if you avoid mechanical components all together it is definitely better.
- sliken 9y ago
  Plenty of moving parts in a car, but the vast majority of them are metal and most with pretty forgiving tolerances. Fast spinning mirrors aren't particularly hard, but the tolerances are pretty unforgiving. Being able to tell if a car is partially in your lane at 200 meters is a pretty small angle. Cars take quite a bit of abuse over their 100-200k mile lifetime. Vibration (at numerous frequencies), huge temperature variations (120F to -20F or so). Not sure I buy that Lidar is better than cameras for cars. Especially since they are cheap enough for you to have a dozen of them. Better price point, and more likely to have the same limitations as eyes do (to fit social expectations). Sadly society seems more focused on failures than a strict rational decision of deciding if a technology is worthwhile based on the numbers of lives saved vs lost. Sure, if someone can make a solid state lidar using the lower frequency light (so they can use 40x stronger laser) it might compete. I'd still worry about blind spots because of fog, smog, snow, sleet, rain, blowing dust, sand storms, etc.
joshvm 9y ago
Moving parts and economy of scale. If you want to buy an industrial 1D LIDAR off the shelf today, you're looking at a few thousand dollars. A galvanometer scanner like these guys use is again, several thousand dollars (just look at Thorlabs for a basic system). InGaS array sensors are also not cheap. Frankly I'm skeptical that a galvo based system will last long in the real world. In principle, flash LIDAR solves all of the problems. You can image an area at long distance in real-time. It has no moving parts and it's presumably amenable to MEMS production. Basic (non-MEMS) units from people like ASC cost tens of thousands. We just need someone with a serious bankroll to develop one. We saw exactly the same with Time of Flight cameras. Microsoft bought Canesta and suddenly a $5k+ camera cost $100.

joshvm 9y ago

So it's a LIDAR + galvanometer scanner in a box? This is nothing particularly novel in itself, except they seem to have solved the scanning-speed problem. If you look at the videos of the scan, you can see that rather than the ring-like scans you'd get from a Velodyne system, you get a kind of snake-path. They're scanning (extremely quickly, by the looks of it) with a mirror and doing a kind of raster pattern. From a skim of their patent it's a multiplexed system - http://www.freepatentsonline.com/y2017/0131388.html http://www.freepatentsonline.com/y2017/0131388.html Seems like they're using a galvo to scan the LIDAR and they're beamsplitting the laser to get multiple returns.

indolering 9y ago
> except they seem to have solved the scanning-speed problem By way of a GaN chip, which is the standard solution for anything requiring super high clock speeds. Considering another company is pitching a $50 solid-state LIDAR for autonomous vehicles, I don't think this qualifies as a breakthrough[0]. It's just the market pushing prices down. [1]: http://spectrum.ieee.org/cars-that-think/transportation/sensors/osrams-laser-chip-for-lidar-promises-supershort-pulses-in-a-smaller-package http://spectrum.ieee.org/cars-that-think/transportation/sens...
- joshvm 9y ago
  I was thinking more of the mirrors. I've used galvo systems at work before, and the off the shelf ones couldn't come close to the sorts of speeds they're showing off. Especially not in a raster pattern. 3D LIDAR using galvos has been done before for space applications (one was used on the space shuttle, or at least a ground-based model), they used a lissajous scanning pattern which is much kinder on the motors because you can do continuous movements rather than making the mirror do a rapid turn at the end of each row. It's called TriDAR: http://adsabs.harvard.edu/abs/2006SPIE.6220E...7R http://adsabs.harvard.edu/abs/2006SPIE.6220E...7R

smoyer 9y ago

As a cautionary warning, a laser with a 1550 nm wavelength can still cause damage to the human eye. I don't know how collimated the laser in this system is but when we piped this color of light down single-mode fiber, looking in the other end could leave you with a dead spot in your retina.

rubidium 9y ago
They said in the article it was low mW. Yes, looking at the other end of a laser fiber is stupid, particularly when your eye can't see the wavelength. If you're working with 1550nm light and single-mode fibers you should know that, and if you don't you should've received better laser safety training.

51Cards 9y ago

Can someone clarify this: "...particularly at 200 meters and beyond. That’s how far cars will have to see at highway speeds if they want to give themselves more than half a second to react to events." 200 meters, half second? That would mean the car is covering 1km in 2.5 seconds, or 1440km/h. Not sure what type of car is going that fast.

mahyarm 9y ago
Processing lag probably contributes
dtparr 9y ago
My reading is that the half second only accounts for reaction time, not stopping distance. Two cars head on at highway speeds would barely be able to stop from a 200m detection.
nathan-muir 9y ago
I think the author is slightly exaggerating here; not that the larger range wouldn't be useful. Assuming that there's a stationary obstruction that you must come to a complete stop. According to [1] the stopping distance of a car travelling at 70mph is 245ft (75m). A car travelling at 70mph is doing approx 31m/s. With a 0.5s reaction time, the car would travel only 90m, or; With a 200m range, the car would have 4s to initiate an emergency breaking manoeuvre. [1] http://www.government-fleet.com/content/driver-care-know-your-stopping-distance.aspx http://www.government-fleet.com/content/driver-care-know-you...

bitmapbrother 9y ago

>But, because it hasn’t got the 360-degree coverage of a rooftop tower, you’d need four units, one for each corner of the car. The technology is certainly interesting and it does have its advantages, but the need to use 4 of these units, for complete coverage, isn't exactly going to make it cheap.

theprop 9y ago

You can be super-human with just cameras. Lidar is not required.

ptero 9y ago

Pencil beam with fast scans coupled to a moving, unstabilized platform can introduce stitching/alignment problems that must be solved to maintain high accuracy. I wonder how well this system does it -- it is not trivial.

jpitz 9y ago

The article mentions that the primary advantage of this approach is that it provides the long distance coverage necessary to handle highway speeds. It also states that, because of the device design, you'd need 4, one at each corner. It seems to me that you don't need 200m coverage to the rear, and maybe the rear of the vehicle could be handled by a less expensive 360-degree lidar unit?

deleted 9y ago
[deleted]

bogomipz 9y ago

The article states: “Current lidar systems can’t see a black tire, or a person like me wearing black—Velodyne’s [Puck] wouldn’t see a 5- to 10-percent reflective object [30 meters away]. It’s the dark car problem—no one else talks about it!” How are the current autonomous vehicles from the Google, Uber et al compensating for this shortcoming? If anyone has some recommendations for learning more about Lidar that they could share I appreciate it.

babo 9y ago
Using more than one sensor helps, radar could see a black car, while lidar not.