[HN Gopher] A Short Introduction to Automotive Lidar Technology
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A Short Introduction to Automotive Lidar Technology
Author : kayson
Score : 234 points
Date : 2024-11-25 20:12 UTC (1 days ago)
(HTM) web link (www.viksnewsletter.com)
(TXT) w3m dump (www.viksnewsletter.com)
| kayson wrote:
| Related: https://www.viksnewsletter.com/p/teslas-big-bet-cameras-
| over...
| Animats wrote:
| Waymo tried cameras-only recently as a research project.[1][2]
| They seem to do about as well as Tesla, which they don't
| consider good enough.
|
| [1]
| https://www.forbes.com/sites/bradtempleton/2024/10/30/waymo-...
|
| [2] https://arxiv.org/pdf/2410.23262
| xnx wrote:
| One of the cool thing about the Waymo Driver is that it can
| be configured to work with different degrees of quality
| depending on the sensors available. In a low risk environment
| (e.g. closed to humans) like operating forklifts in an
| autonomous warehouse, it would work fine with just cameras.
| Waymo hasn't been very boastful to date, but some of the
| capabilities are hinted at in this interview:
| https://www.youtube.com/watch?v=d6RndtrwJKE
| MaxPock wrote:
| Fantastic tech that Musk hates
| quonn wrote:
| It's not just Musk. Most automobile manufacturers have
| maintained that they need to find a way to do it with cheap and
| pretty sensors.
| juliushuijnk wrote:
| > have maintained that they need to find a way to do it with
| cheap
|
| If the goal is to make roads safer. Aiming for cheap is good,
| it means aiming for more people who can afford that safer
| car. If it's not safer than humans, it should not be on the
| road in the first place.
| tgaj wrote:
| Theoretically if a human can drive a car using a pair of eyes
| connected to brain, it should be possible to do that using
| two cameras connected to some kind of image processing unit.
| fragmede wrote:
| If we want the sell driving computer to be only possibly as
| good as a human. I can't see in the dark, can't see through
| fog, and have trouble with rain. Why is human visibility
| the bar to meet here?
| fragmede wrote:
| Oh and the sun. I get blinded when the sun is in my eyes
| at sunrise and sunset.
| tgaj wrote:
| And how many car accidents did you cause in your life?
| Probably still no a lot even with your flawed vision.
| itishappy wrote:
| In theory. In practice neither the cameras nor processors
| available in cars function anywhere near human level.
| vel0city wrote:
| It's not even entirely true in theory. We use a lot of
| our senses when driving. Force feedback on the wheel.
| Sounds from the environment. Inertial senses. And our
| vision isn't fixed, its constantly moving.
|
| And yeah, as you mention, cameras don't really have the
| same level of range our eyes have and computers don't
| operate in the same way.
| knifie_spoonie wrote:
| In practice humans aren't particularly safe drivers.
| xdmr wrote:
| Is that because their vision fails to provide the
| information necessary to drive safely? Or is it due to
| distraction and/or poor judgment? I don't actually know
| the answer to this, but I assume distraction/judgment is
| a bigger factor.
|
| I'm not a fan of the camera-only approach and think Tesla
| is making a mistake backing it due to path-dependence,
| but when we're _only_ talking about this is _broadly
| theoretical_ terms, I don't think they're wrong. The
| ideal autonomous driving agent is like a perfect monday
| morning quarterback who gets to look at every failure and
| say "see, what you should have done here was..." and it
| seems like it might well both have enough information and
| be able too see enough cases to meet some desirable
| standard of safety. In theory. In practice, maybe they
| just can't get enough accuracy or something.
| ra7 wrote:
| > _Is that because their vision fails to provide the
| information necessary to drive safely?_
|
| In certain conditions, yes. Humans drive terribly in dark
| and low light, something lidar excels in.
| tgaj wrote:
| Still, millions of humans drive every night and only a
| miniscule percentage cause any accidents. So maybe we are
| not so bad at this.
| ra7 wrote:
| According to NHTSA, about half of all fatal crashes occur
| at night, even though only 25% of driving happens at
| nighttime. So yes, we are pretty bad at this.
| tgaj wrote:
| I totally agree, I think most accidents are caused by
| human nature (especially slow reaction time in specific
| conditions like being tired or drunk) and ignoring laws
| of physics (driving too fast). And some are just a pure
| bad luck (something/someone getting on the road right in
| front of the car).
| jdhwosnhw wrote:
| Imagine that same reasoning applied to the car itself. Ugh,
| wheels?? Humans get around just fine bipedally, so cars
| should have legs too.
| dawnerd wrote:
| Explains the Tesla robot actually
| carbotaniuman wrote:
| Theory isn't really all that applicable to this though - in
| theory nothing is stopping anyone from writing all code in
| assembly, but obviously that doesn't happen.
|
| I think more practically cars have adding driver assistance
| feature for a while now - more cameras, blind spot
| monitoring, ultrasound for parking, lane drift indicators.
|
| It is therefore not unreasonable to assume that adding more
| sensors is helpful (but even the old adage of more data is
| better than less would probably say that).
| tgaj wrote:
| To be honest, it's possible that having too much data can
| only cause problems in quick decision-making. Any
| redundant data will only slow down processing pipelines.
| KeplerBoy wrote:
| Sure, but why strive for that? We can have better than
| human perception by adding lidar and radar.
| ProblemFactory wrote:
| > Theoretically it should be possible to do that using two
| cameras connected to some kind of image processing unit
|
| That "some kind of image processing unit" in humans has an
| awful lot of compute power and software.
|
| If you remove $100k of sensors but have to add $200k of
| compute to run more advanced computer vision software, then
| it's a bad tradeoff to use only cameras, even if in theory
| that software is possible.
| Klaus23 wrote:
| This is simply not true. Let's look at the best autonomous
| driving features available today, i.e. level 3:
|
| Mercedes Drive Pilot: Uses a lidar (and a dummy unit) up
| front.
|
| BMW Personal Pilot: Uses a lidar (and a dummy unit) up front
|
| Honda SENSING Elite: Uses 5! lidars
|
| They all use lidar, and some of the placement locations are
| downright hideous (Mercedes EQS). I think further development
| will require even more/better sensors, and manufacturers tend
| to agree on this point.
| asdasdsddd wrote:
| What are the benchmarks that say Mercedes, BMW, and Honda
| have the best level 3 features.
| fragmede wrote:
| Don't forget Blue Cruise from Ford.
| Klaus23 wrote:
| Blue Cruise is level 2+, not 3, and does not rely on
| lidar.
| Klaus23 wrote:
| I ignore the Chinese because it is difficult to get
| reliable English information. Apart from those, these are
| the only level 3 systems available, and level 3 is the
| most advanced system that private individuals can
| currently get their hands on. Have I missed any?
| luos2 wrote:
| It's not a benchmark, but there is a youtube channel (Out
| of Spec) which tests these systems, and I think they also
| say Mercedes are the best in their "Hogback challenge".
|
| https://www.youtube.com/watch?v=xK3NcHSH49Q&list=PLVa4b_V
| n4g...
|
| Worth checking out, many cars are very bad.
| GoToRO wrote:
| Sponsored by Magna, probably the contractor selling them
| the system...
| ra7 wrote:
| Chinese OEMs (BYD, Xaomi, Nio) use lidar in almost all of
| their mid to premium segments. Also, Polestar 3.
| UltraSane wrote:
| How well do they work? Camera only systems can be easily
| blinded by sun, fog, dirt, and snow
| quonn wrote:
| Maybe they changed their mind on it in the last 10 years. I
| had as the source a high-ranking BMW manager as well as an
| Audi one who each gave a public lecture at a university
| with such a statement.
| Klaus23 wrote:
| After a bit of research, I found out that they apparently
| did. Obviously every manufacturer would like to be able
| to use only proven technologies such as cameras and radar
| because they are cheap. One of the early Mercedes
| prototypes seemingly didn't have lidar
| <https://www.youtube.com/watch?v=DlgGTi4Gs50&t=79>.
|
| Since then, the consensus has been that without lidar,
| the systems would not meet safety standards. For example,
| the cars need to be able to detect fairly flat objects,
| such as pallets that have fallen onto the road, which are
| very difficult to see optically, especially in difficult
| lighting conditions. For this reason, and because the
| technology has come down in price, virtually everyone
| except Tesla, which is developing advanced driving
| systems, is using lidar.
|
| This development is nearly a decade old. It is for this
| reason, combined with the overwhelming amount of Musk-
| related nonsense, that I objected so strongly.
| tordrt wrote:
| All of these are far less capable than FSD. They might have
| more advanced regulatory approval because they have strong
| limitations of when it can be used, but if you drive the
| same route and compare, its not even close.
| Klaus23 wrote:
| I doubt it. Yes, FSD is more flexible and can also drive
| reasonably well on city streets, but there is a reason
| why it is not certified for level 3 on motorways. It
| would most likely fail certification. With a level 3
| system, I can take my eyes off the road and watch a
| movie. Doing that with FSD, even in the best conditions,
| is suicidal. Level 3 vehicles must have an extremely low
| failure rate. Any crash would quickly be picked up by the
| media.
|
| FSD is a versatile level 2 system, but at best a
| prototype for level 3. If we are talking about
| prototypes, it has to be compared to prototypes from
| other manufacturers like this
| <https://www.youtube.com/watch?v=0uSph0asNsk> fully
| autonomous system from ... 11 years ago. The reason FSD
| is available to the average consumer is mostly a matter
| of philosophy, not technology.
| Symmetry wrote:
| If you want conventional car utilization where the car sits
| in a parking spot most of the time then the extra cost from
| the lidars is much more of an issue than if you're operating
| a fleet that is acting as taxis most of the day.
| r17n wrote:
| So there's a video of him addressing this - he doesn't hate the
| tech. He mentions that it's wildly expensive for cars. But,
| they use it heavily for SpaceX
| threeseed wrote:
| The issue isn't that it's wildly expensive for cars. But
| rather for Tesla.
|
| Because the company has promised that existing Tesla owners
| would be able to use FSD.
|
| Having to retrofit them to add LiDAR sensors would be cost-
| prohibitive.
| stormfather wrote:
| Also he wants to reuse the foundational machine vision tech
| in Optimus bot, which probably won't have lidar.
| threeseed wrote:
| Based on presentations we've seen what sets Tesla apart
| are its datasets not the core technology.
|
| And those don't translate across to the Optimus bot.
| stormfather wrote:
| I think they will though, I think the enormous corpus of
| video data and the supercluster that powers self driving
| development are the machine vision analog of internet
| scale text data that gave rise to LLMs. We'll see the
| same moment for vision models that text prediction models
| had once the data is there, where an enormous foundation
| model becomes much much better, especially at zero-shot
| tasks.
| threeseed wrote:
| FSD is already using the fruits of this today with their
| end to end NN.
|
| And based on what we've seen the results haven't improved
| enough to put them close to Waymo.
| sroussey wrote:
| Optimus should probably have LiDAR more than a car...
| stormfather wrote:
| I would guess the plan is to have the foundational
| machine vision tech that becomes the core of robotics
| sensors. Not just Optimus but every robot arm in a
| factory, robot mule, etc. I don't think everything will
| have LIDAR if its proven to be unnecessary.
| threeseed wrote:
| The foundational tech Tesla is using is the same as
| everyone.
|
| We know this because there have been public presentations
| about it.
|
| And inventing groundbreaking new tech is so far the
| domain of academia and large, well funded R&D labs. And
| almost always shared.
| kieranmaine wrote:
| In a recent No Priors podcast with the Waymo Co-CEO Dmitri
| Dolgov, he talks about how they evaluated just driving with
| cameras and how it isn't good enough for full autonomy and
| doesn't meet their bar for safety [1].
|
| 1: https://www.youtube.com/watch?v=d6RndtrwJKE&t=1119s
| jaimex2 wrote:
| They went deep down the wrong path and need to justify their
| mistake. Waymo will be killed off any day now.
| bobsomers wrote:
| That's a bold claim. Care to justify it?
| jaimex2 wrote:
| Yeah, it only works in extremely controlled environments
| driving really slowly.
|
| The design is also flawed as it has to work with cameras
| anyway. The last thing you want is two systems arguing
| over what they see.
| Infinitesimus wrote:
| It doesn't have to be an argument. You know what each
| system is good at and prioritize inputs accordingly.
| ra7 wrote:
| Extremely controlled environments like the entire city of
| San Francisco?
|
| Sensor fusion is a thing. There are no two systems that
| "argue with each other". I can't believe the same old
| ignorant tropes are still making rounds.
| coolspot wrote:
| Waymos don't drive slowly, I don't know where you're
| getting this from. If anything, they drive too fast for a
| thing without a driver.
| adamweld wrote:
| Nice, you just outed yourself as being completely
| clueless. There exist many good sensor fusion techniques
| for summing the output of disagreeing sensors.
| ra7 wrote:
| Google killing off Waymo by giving them $5.6B just a few
| weeks ago!
| UltraSane wrote:
| What do they actually use that much money for?
| ra7 wrote:
| New vehicles and setting up depot operations.
| JaggedJax wrote:
| From person experience, the state of the art Tesla vision
| FSD still can't drive east at sunrise, west at sunset, or
| in moderate rain. I haven't seen any sign of them solving
| that fundamental problem with vision, especially given
| there are existing non-vision solutions.
| UltraSane wrote:
| I find opinions like this to be almost as crazy as saying
| that the earth is flat because Waymo has a working, truly
| self-driving taxi service RIGHT FREAKING NOW while Musk is
| still promising to have one some day in the hazy future
| while NEVER making a single vehicle that can actually drive
| without someone in the car. Musk rejecting LIDAR means that
| he fundamentally doesn't understand the technological
| challenge of self-driving despite have access to the
| world's experts OR he is cynically using false promises of
| self-driving to pump up Tesla share price. I know which one
| I think is true.
| altacc wrote:
| I think anyone who listens to Musk talking about
| something they themselves know a lot about quickly
| realises that Musk's skills are elsewhere. He can
| motivate and market the hell out of a business whilst
| snorting more ketamine than a herd of horses but he is
| not a technical genius by any means. He pays people well
| to agree with him and fires them when they don't, so I
| suspect that his companies that produce better and more
| stable products do so because he micromanages them less.
| mavhc wrote:
| It's weird that what he does is so easy yet no one else
| is making EVs at scale in USA, or landing rockets, 10
| years after SpaceX did it
| jaimex2 wrote:
| It doesn't. It has a party trick that works in very
| specific conditions.
| olabyne wrote:
| At least it works. Meanwhile Tesla have nothing to show,
| even in "very specific conditions".
| KeplerBoy wrote:
| Do you expect a car with fewer sensors to fare any better
| soon?
| UltraSane wrote:
| But it works vastly better than anything Tesla has made
| so what does that say about Tesla?
| tordrt wrote:
| Karpathy said in some podcast that Tela uses LIDAR in
| training, and by doing this they can get a lot of the
| benefits. Not sure that all off the "worlds experts"
| agree with you that you HAVE to use LIDAR. Rate of
| progress for FSD has been very impressive lately. I
| personally think that its very plausible that Tesla might
| beat Waymo to large scale location independent autonomous
| driving.
| UltraSane wrote:
| The stats on the latest FSD are still terrible. It still
| needs human intervention far too frequently and is no
| where near being able to run without a human in the car
| or Tesla accepting liability for crashes.
| willy_k wrote:
| > Rate of progress
| reportingsjr wrote:
| Waymo's recent experiment with multimodal models and a
| purely camera based system (EMMA) validate some of the
| claims that using LIDAR data in training does help.
| Pretty neat! Still not as good as a LIDAR + RADAR based
| system.
| jaimex2 wrote:
| Musk has said several times Lidar is great. It's just a stupid
| idea for automotive use and he's not wrong.
|
| There's nothing similar in nature for a reason.
| itishappy wrote:
| Time of flight ranging is used in nature by bats and
| whales/dolphins.
| fragmede wrote:
| and humans! https://www.atlasobscura.com/articles/how-to-
| echolocate
| password4321 wrote:
| 2024 https://news.ycombinator.com/item?id=42160071
|
| 2018 https://news.ycombinator.com/item?id=18208334
| maxbond wrote:
| My back of the napkin estimate is that a human using time
| of flight ranging would be unable to distinguish between
| an object directly in front of their face and 8.6 meters
| away[1]. I think human echolocation uses a different
| mechanism (presumably relating to amplitude)?
|
| Skimming the Wikipedia article[2], it seems like animals
| do use time of flight, but also Doppler shifting.
|
| (As a side note, some animals have apparently evolved
| active countermeasures to echolocation!? It seems obvious
| in retrospect but incredibly cool.)
|
| There's interesting research into the mechanisms of human
| echolocation [3], but it was over my head. My impression
| was that the jury is out as far as the precise mechanisms
| involved but that there's a lot of evidence to be
| considered, I'm sure someone with a better background
| would get more out of it than I did.
|
| (I'm just curious about the mechanism, I agree that LIDAR
| has natural analogs.)
|
| [1] Speed of sound * 25ms, 25ms being the rule of thumb
| I've memorized for the minimum interval for two sounds to
| register as distinct from each other. This is just folk
| wisdom I've picked up hacking on audio, so perhaps I'm
| mistaken.
|
| [2] https://en.wikipedia.org/wiki/Animal_echolocation
|
| [3] https://durham-
| repository.worktribe.com/preview/1375913/1963...
| jaimex2 wrote:
| Both primarily use their eyes. Look it up.
| igorstellar wrote:
| Rotorwings are also not found in the nature yet they give us
| ability to navigate in a short distance 3D space better than
| fixed wing.
| bobsomers wrote:
| Airplanes don't flap their wings and boats don't wag their
| tails.
|
| Assuming that all technology should imitate nature is a naive
| engineering principle. The solution should solve the problem
| within the given constraints.
| jaimex2 wrote:
| Nature came up with something much better in both those
| cases.
|
| Portable, energy efficient, light, doesn't need refined
| oil, tightly steers...
|
| Boats and aeroplanes are terrible in comparison. They only
| work due to a huge network of global effort.
| 542354234235 wrote:
| >They only work due to a huge network of global effort.
|
| And horses don't need roads like cars do and cars only
| work thanks to a huge network of global effort. What
| point are you trying to make? That we abandon planes
| until we can develop flight as efficient as nature?
| Abandoning LIDAR until we can develop visual light
| perception and processing equal to the human eye and
| brain?
| vel0city wrote:
| I don't see many birds around able to carry an extra
| 280,000lbs for 2,300 miles without having a meal.
| bluGill wrote:
| Nature makes for bad drivers. for some age groups cars are
| the largest causeof death. I self driving can do better.
| edm0nd wrote:
| Bats kinda have Lidar.
| jaimex2 wrote:
| Echo location but they still mostly use their eyes. Same as
| dolphins
| willy_k wrote:
| Wouldn't it be sonar?
| UltraSane wrote:
| Because Musk thinks is much much smarter than he actually is
| and refuses to listen to anyone. And between how many people he
| fired at Twitter, Tesla, and soon the US Federal Government I
| think he gets off on it.
| rightbyte wrote:
| "Its particular superpower is that it can generate high
| resolution images of its surroundings much better than radar
| can."
|
| Is this true tough? Car radars are fixed. I guess a comparable
| lidar would be fixed too and have n points for n lasers.
|
| A rovolving radar would have continuous resolution around while a
| lidar samples?
|
| I thought the advantage of lidars were accuracy and being better
| at measuring heights of objects, where as radars flatten the
| view.
| lupusreal wrote:
| Very high tech radars can generate amazing imagery, but they'll
| never top what lidar can do. Conceptually they're both doing
| the same sort of thing using EM radiation, but lidar uses a
| _much_ smaller wavelength which gives it an intrinsic
| resolution advantage. Particularly at distances and with
| hardware sized relevant to cars.
| ender7 wrote:
| The issue isn't one of fixed vs rotation, it's that radar can't
| fundamentally achieve the resolution necessary to distinguish
| important features in the environment. It's easily fooled by
| oddly-shaped objects, especially concave features like corners,
| and so while it's great for answer the question of "am I close
| to something" it's not reliable for telling you what that
| something is, especially at longer ranges.
| xnx wrote:
| I believe automotive radar has a cone of sensitivity that is
| read as a single "pixel" worth of data. Even if the radar spun
| like lidar, the radar cone of sensitivity is thousands of times
| wider than the lidar beam so you can't make much of a picture
| with radar.
| 0_____0 wrote:
| IIRC the data coming out of the Conti radars was preprocessed
| to give bearing, distance, and size of an object in the FOV
| of the unit. I don't know if I ever saw the true raw data out
| of one of them, but I'm curious what it looks like.
| itishappy wrote:
| I'd be curious if the design of the Cybertruck affects
| readings at all. It's got angles straight outta an F-117.
| 0_____0 wrote:
| I reckon it's probably not that bad, there are big
| surfaces that are almost normal to what would be incoming
| radio energy. Stealth shapes tend to reflect energy in a
| completely different direction from the source.
| itishappy wrote:
| Here's the closest thing to data I've been able to find.
| I have no idea what to do with this info.
|
| https://x.com/jwt0625/status/1848218860513628203
| 0_____0 wrote:
| The polar plot at the end would be useful if there were
| plots for other cars and trucks to compare to. I'm
| assuming that it's a simulation?
| rightbyte wrote:
| I think "stealth" planes assumes the radar is under the
| plane on the ground? For the geometry. And they have some
| color or alloy that reflect less.
| 0_____0 wrote:
| It's cooler than that these days - under the paint are
| antennas plated? printed? onto the skin panels that are
| tuned to absorb specific frequencies of interest.
| rightbyte wrote:
| Ye I have a hard time imaganing how a car radar image looks
| like.
|
| On boat radars it seems like the radar have really high
| resolution (can see much further than lidars) but have
| worse accuracy. I.e. things looks like blobs.
|
| A lidar image at 50+ meters is very sparse.
| jeffreygoesto wrote:
| Roughly like in this paper https://www.semanticscholar.or
| g/paper/RadarScenes:-A-Real-Wo...
| rightbyte wrote:
| Thanks. Spot on!
| ndileas wrote:
| "Size" might be as simple as radar cross section. Not
| necessarily a good thing for us squishy blobs.
| Animats wrote:
| That's a reasonable basic overview.
|
| I'm surprised that rotating scanners are still used. It's been
| twenty years since Velodyne built their first one. They work OK,
| but cost too much. I was expecting flash LIDAR or MEMS mirrors to
| take over. Continental, the auto parts company, bought the
| leading flash LIDAR company over a decade ago, but the volume
| market a big parts company needs never appeared.
|
| Waymo is still using rotating LIDARs even for the little ones at
| the vehicle corners. Those need less range. There needs to be a
| cheap, flush-mounted replacement for those things. The location
| is too vulnerable. Maybe millimeter phased array radar mounted
| behind Fiberglas body panels. Waymo needs to solve that problem
| before they do New York.
|
| The LIDAR on top may not be a problem. Insisting that it has to
| go away to "look like a car" is like insisting that cars had to
| have the form factor of horse-propelled buggies. Early cars
| looked like buggies, but that didn't last.
|
| One big advantage of pulsed LIDAR over continuous is that the
| interference problem between identical units is much less. The
| duty cycle is tiny. Data from one pulse round trip is collected
| in less than a microsecond. Just put some randomization in the
| pulse timing and getting multiple conflicts in a row goes away.
| xnx wrote:
| > They work OK, but cost too much.
|
| Costs have dropped dramatically in the past 20 years and
| continue to do so.
|
| > There needs to be a cheap, flush-mounted replacement for
| those things.
|
| Why? Corners are the optimal mounting position for maximum
| visibility. It allows the car to -in-effect- see around corners
| in ways no centrally mounted sensor can.
|
| > Waymo needs to solve that problem before they do New York.
|
| What? Because of vandalism?
| aftbit wrote:
| Have you ever seen the corners of a car that has been parked
| in a big East-coast city? They will sustain damage during the
| course of normal operation and storage, and many people will
| not stop and leave their insurance information, especially if
| the damage is perceived as minor and happens while the car is
| parked and the owner not present. Currently, the corners of a
| car are relatively non-critical to its function and usually
| not too expensive to repair. If both of those change, we'll
| see more expensive damage that is more challenging to repair
| as well as less likely to be handled by the responsible
| party.
|
| Also, having the sensors stick out from the corners makes the
| car's collision box and turning radius bigger. That doesn't
| help in any tight situation, but I imagine that's not that
| different between e.g. SF and New York. What is different is
| the sheer volume of cars and pedestrian activity.
| AlotOfReading wrote:
| They don't stick out that much. The geely vehicle has front
| sensors recessed just above the front wheel well, without
| much additional side clearance. Either way, a collision
| involves regulatory filings, downtime, and sensor
| recalibration even if no damage is sustained.
| m0llusk wrote:
| Waymos sometimes stop briefly in parking spots while
| waiting for assignments, but they don't really park as such
| except in special lots. The big problem I have seen is they
| tend not to always pull to the curb when releasing
| passengers and if a door is left even slightly ajar then
| they will sit there requesting the door be closed even if
| they are blocking a lane with many cars behind them
| beeping.
| UltraSane wrote:
| Not having a motor and thus having to depend on people to
| close doors on an autonomous car seems very silly.
| xnx wrote:
| Waymo's custom designed 6th generation vehicles[1] with
| self-closing doors were expected to enter service this
| year, but have [probably] been put on indefinite hold due
| to tariff issues
|
| [1] https://waymo.com/blog/2021/12/expanding-our-waymo-
| one-fleet...
| UltraSane wrote:
| can't they retrofit a door closer to their current cars?
| mrguyorama wrote:
| Minivans have had powered doors for decades and make
| great taxis, why do they need a special vehicle for this?
| xnx wrote:
| An earlier version of Waymo's vehicle was based on the
| Chrysler Pacifica. Like in a lot of areas, if you're
| going to spend billions of dollars to buy thousands of
| some product, it is worth customizing it for the specific
| purpose.
| Animats wrote:
| Right. It seems to have been Waymo's decision to have zero
| blind spots around the vehicle perimeter, even if that
| means having the sensors stick out.
|
| Cruise had an accident where another vehicle knocked a
| pedestrian into a Cruise car, and the pedestrian was
| dragged. Cruise lost their California DMV autonomous
| license for that. So there's a good case for full perimeter
| coverage.
|
| Humans don't have that. The same week as the Cruise
| incident, a NYPD tow truck dragged a pedestrian some
| distance because they were in a blind spot for the driver.
| Filligree wrote:
| Did the tow truck driver lose their license?
| ljlolel wrote:
| They lost their license for not reporting it properly (as
| required under the license). Not for the accident.
| financetechbro wrote:
| I think it's due to how often cars bump or scratch against
| each other in NYC (I.e. the sensors are in a vulnerable spot
| to be easily damaged).
|
| It's quite funny seeing the number of cars that have bumper
| skirts in NYC to help minimize damage from inevitable close
| encounters with other vehicles
| 0_____0 wrote:
| Waymo have in house radar, I think in the 70GHz gap in the
| absorption spectrum. They're pretty obvious as sort of
| paperback book sized planes, mounted near other sensors IIRC.
|
| The old Velodyne units were actually susceptible to damage if
| you left two units running right next to each other. I did hear
| a proposal at some point for a different but similar unit to
| use GPS time to sync the rotations of all the units we had live
| so they wouldn't be pointed at each other, but in practice it
| seemed to not be a huge issue.
|
| BTW I once gave you guff about continuing to bring up Conti's
| flash LIDAR, and in retrospect I wish I hadn't, I really enjoy
| your contributions here.
| Animats wrote:
| I went down to Advanced Scientific Concepts in Santa Monica,
| CA, in 2003 to see their prototype flash LIDAR. It was on an
| optical bench aimed out an overhead door into daylight,
| nowhere near a product. It did work, but required strange
| InGaAs semiconductor processes and a timer chip stacked back
| to back against the sensor chip. Way too expensive to fab.
|
| I thought that was going to be the future, and that
| technology would get cheap. But it's still expensive to fab
| such devices.
| wbl wrote:
| Si interpoisers are a pretty mainstream packaging
| technology nowadays, so that might help with the stacking
| bits.
| deepnotderp wrote:
| The SNR for flash Lidar is really low because you spread the
| beam out over such a large area.
|
| Most automotive Lidar already operate in a "photon starved
| regime", ~200-300 photons per return[0]. If you spread that
| over the entire scene, your snr drops quickly.
|
| This forces you into 1550nm, and a large detector array and
| high power laser at 1550nm is extremely expensive.
|
| As for MEMS, it's been a while but I think FOV/steering angle
| range , steering speed and even maximum beam power were
| concerns
|
| EDIT: my Lidar friend Jake reminded me that the appetizer size
| is also an issue with MEMS- smaller aperture = less light
| collected = lower SNR
|
| [0] https://www.hamamatsu.com/content/dam/hamamatsu-
| photonics/si...
| hwillis wrote:
| > Most automotive Lidar already operate in a "photon starved
| regime", ~200-300 photons per return[0]. If you spread that
| over the entire scene, your snr drops quickly.
|
| Translating: Normally you have a large single sensor per
| laser, which makes measurements at a very high rate. With
| flash lidar, you split the sensor up like an image sensor. In
| a normal image sensor, each pixel can collect light for a
| _long_ time, but if you do that with lidar you have no
| distance resolution. The sensor is sitting idle 99% of the
| time, and you pay in sensitivity and accuracy.
|
| Array sensors, MEMs, and phased arrays all struggle because
| they're all really good at small-angle differences, while the
| reason for scanning lidar is large-angle differences. Maybe
| one day we'll start making curved dies and it'll be easier to
| have a really wide FOV without needing multiple sensors.
| deepnotderp wrote:
| You can actually make curved dies already- there's a
| company doing that for image sensors, if you thin silicon
| down it becomes flexible
| JayPalm wrote:
| Continental is folding their automotive LiDAR division and is
| laying off everybody.
| Animats wrote:
| Not surprised. I don't think they sold many.
| michaelt wrote:
| _> I 'm surprised that rotating scanners are still used. It's
| been twenty years since Velodyne built their first one._
|
| They're even older than that. SICK have been pointing laser
| range finders into spinning mirrors since about 1995 - albeit
| mostly for industrial safety systems which can be quite price-
| insensitive.
|
| There's a few things to know about LIDAR to understand why
| spinning lasers make sense.
|
| First of all, anything emitting a cone of light encounters
| "inverse square dropoff" - where moving twice as far away means
| you get a quarter of the light, per unit area. This is most
| visible with flash photography at night - but it also applies
| to LIDARs. And in an automotive application, ideally you want
| to be able to sense things 100m away. Illuminating a laser spot
| is much more practical than illuminating everything.
|
| Secondly, whatever light source you use has to be eye-safe. And
| sure, IR has safety advantages over visible light here - but a
| light source bright enough to illuminate things at a 100m
| distance would be very hard to make safe, even with the
| advantages of IR. As a scanning laser never lingers in one
| point for long, it can safely be much more intense.
|
| The third thing to know is whatever light source you're using,
| you're in competition with the sun. Sometimes the sun is low in
| the sky and directly dazzling your sensors. Other times it's
| illuminating the same things you want to illuminate. This means
| you can't make up for a weak light source and inverse-square
| dropoff with clever signal processing.
|
| And finally, the makers of these cars envisage a future where
| every single vehicle on the road is using this technology. So
| there's also a risk of the reflected returns of two different
| vehicles interfering with one another. Even rotating LIDAR can
| be vulnerable to it, but flash LIDAR is _particularly_
| vulnerable.
|
| Meanwhile, automotive companies aren't scared of moving parts.
| A car has loads of spinning parts already; they have mastered
| the art of making spinning things that can keep spinning for
| thousands of hours.
| rrr_oh_man wrote:
| _> Meanwhile, automotive companies aren 't scared of moving
| parts. A car has loads of spinning parts already; they have
| mastered the art of making spinning things that can keep
| spinning for thousands of hours._
|
| Almost an understatement.
|
| A typical car wheel hub with a 20-27 inch tire diameter has
| experienced around 75-100M full rotations by the time it
| reaches 100K miles.
|
| Meanwhile, the engine probably has revolved ~5-10 times more
| during the same time.
| raisedbyninjas wrote:
| I may be wrong, but I think the concern was delicate
| components protruding from the body are susceptible to
| damage in urban areas.
| HPsquared wrote:
| Cars already have mirrors and lights etc. LIDAR is in the
| same family as those.
| vel0city wrote:
| Mirrors and lights are generally cheaper than a whole
| LIDAR unit when I get lightly sideswiped.
| HPsquared wrote:
| I figure if the LIDAR is mass produced on every car, it
| won't be much more than a headlight. (Headlight prices
| notwithstanding)
| atomic128 wrote:
| Here's an interesting "lidar gem" from Hacker News a few years
| ago:
|
| https://news.ycombinator.com/item?id=33554679
|
| _Lidar obstacle detection algorithm from a Git repo leaked onto
| Tor_
|
| _This is a drivable region mapping (obstacle detection)
| algorithm found in what appears to be a git repo leaked from an
| autonomous vehicle company in 2017. The repo was available
| through one or more Tor hidden services for several years._
|
| _The lidar code appears to be written for the Velodyne HDL-32E.
| It operates in a series of stages, each stage refining the output
| of the previous stage. This algorithm is in the second stage. It
| is the primary obstacle detection method, with the other methods
| making only small improvements._
|
| _The leaked code uses a column-major matrix of points and it
| explicitly handles NaNs (the no-return points). We 've rewritten
| it to use a much more cache-efficient row-major matrix layout and
| a conditional that will ignore the NaN points without explicit
| testing._
|
| _This is an amazingly effective method of obstacle detection,
| considering its simplicity._
| arrakark wrote:
| Which Tor hidden service was this?
|
| Asking for a friend...
| edm0nd wrote:
| If it was leaked in 2017, that's when Tor hidden service v2
| URLs were still in use. Meaning the site is long gone and
| inaccessible these days.
| hammock wrote:
| Are LIDAR dangerous to the eyes of other drivers or pedestrians?
| itishappy wrote:
| They should not be. In theory they can be, but there are strict
| regulations to prevent that.
| hammock wrote:
| What are the regulations and who are the relevant regulatory
| bodies? I could not find with a google search
| AlotOfReading wrote:
| They fall under the same regulations as lasers.
| hnisoss wrote:
| Those can be gamed easily.
| itishappy wrote:
| Please explain!
| itishappy wrote:
| Good question! You're right, this is surprisingly hard to
| Google. It looks like the FDA is responsible. I would not
| have guessed that!
|
| The National Highway Traffic Safety Administration (NHTSA)
| would have been my guess, but I'm not finding much there.
| They have a spec for LIDAR speed measurement devices, and
| one for the required sensors in vehicles, but nothing on
| the the output of said sensors.
|
| > For manufacturers of laser products, the standard of
| principal importance is the regulation of the Center for
| Devices and Radiological Health (CDRH), Food and Drug
| Administration (FDA) which regulates product performance.
| All laser products sold in the USA since August 1976 must
| be certified by the manufacturer as meeting certain product
| performance (safety) standards, and each laser must bear a
| label indicating compliance with the standard and denoting
| the laser hazard classification.
|
| https://www.lia.org/resources/laser-safety-
| information/laser...
|
| https://www.fda.gov/radiation-emitting-products/home-
| busines...
|
| https://www.fda.gov/about-fda/fda-organization/center-
| device...
| hammock wrote:
| Sorry, I don't believe the FDA is doing anything more
| than stamping a Class 1 or class 2 sticker on component
| parts. They are not testing LIDAR arrays in situ under
| simulated driving conditions
|
| I would like to see crash test dummy style research
| around vehicular LIDAR
| kube-system wrote:
| Crash tests in the US are also technically on the honors
| system too, but NHTSA does test the most common models.
| But many they don't. For example, the Cybertruck.
| itishappy wrote:
| Classification should be sufficient. Remember that LIDAR
| is invisible, so distraction or flash-blindness are not
| relevant, just health effects. Class 1 has already been
| thoroughly tested and deemed "safe even for long term
| intentional viewing." Class 2 is visible only, so any
| LIDAR systems above 5mW would be Class 3, which are
| deemed harmful to humans. You can put a Class 3 laser in
| public (see laser light shows) but the FDA regulations
| require an indicator and to give the public enough
| warning to get clear if desired. These restrictions are
| going to make anything but Class 1 LIDAR exceedingly
| difficult for use in automotive applications.
| sroussey wrote:
| I know we are talking about car type lidar, but the iPhone Pro
| has a type of one and gets a depth map of photos. So you're
| shooting it everyone you are taking photos of.
| KaiserPro wrote:
| I don't think the Lidar in apple's stuff is actually a lidar,
| I think its a structured light sensor.[1]
|
| What do I mean by that? lidar sends pulses of light and works
| out the difference between emission time and arrival time to
| work out how far the pulse has travelled.
|
| The structured light sensor emits a pattern or dots, and any
| distortion of that can be used to compute the shape of an
| object.
|
| [1] https://image-ppubs.uspto.gov/dirsearch-
| public/print/downloa...
| flutas wrote:
| They aren't talking about FaceID.
|
| iPhone 12 introduced a lidar sensor in the back.
|
| https://www.nature.com/articles/s41598-021-01763-9
| deepnotderp wrote:
| No, there's a class system for laser safety
|
| The rating is for you to stick your eyes right up to it for a
| long period of time and still be fine
| hammock wrote:
| What's "a Long time"? Does it cover a 2 hour commute in
| traffic with 20+ cars around you blasting it continuously any
| direction you look, invisibly?
| Symmetry wrote:
| Laser safety ratings are based on what would happen if the
| laser was pointed directly at your eye continuously. In the
| case of general traffic each lidar is scanning in different
| direction and while manufacturers try to make the energy
| produced by their lasers instantaneously brighter than the
| sun in one specific wavelength but damage to your retina is
| caused by excessive heating and doesn't care about what
| wavelength the energy is coming in at in the IR except to
| the extend that it can get to the retina or not. In your
| morning commute I'd worry less about the lidars than the
| much larger amount of invisible IR radiation given off by
| the sun. And I'd worry much less about the sun's IR
| radiation than the sun's UV radiation, wearing sunglasses
| during a 2 hour commute is best for your eyes.
| hnisoss wrote:
| 1550nm LiDAR Damaged Sony Camera at CES - http://image-sensors-
| world.blogspot.com/2019/01/1550nm-lidar...
| hammock wrote:
| Thanks for sharing that, clearly there is something at least
| worth investigating here. The concern about long-term
| exposure to LiDAR beams is not extensively studied. Current
| regulations seem to primarily focus on short-term exposure
| limits, and there is a lack of comprehensive testing under
| real-world conditions
| brcmthrowaway wrote:
| Is there a lidar unit I can take home and scan my house at high
| resolution (than iphone)?
| beeburrt wrote:
| I was wondering this too, although for a different use-case. A
| couple years ago I was walking through a field/vacant lot not
| far from Centralia, WA and I came across what I think is a
| grave.
|
| The (supposed) "grave" was roughly human-sized and human-
| shaped, the ground was concave, sunken in and deepest at the
| center, and it was encircled with stones that were slightly
| larger than grapefruit.
|
| The reason I suspect it's a grave is because I stumbled upon a
| very similar-looking thing at a historical site in Tooele
| county Utah named Mercur cemetery.
|
| With Lidar I could prove/disprove my grave theory, correct?
| edm0nd wrote:
| I think Ground-penetrating radar (GPR) would be better usage
| for this grave scenario vs LIDAR.
| twelvechairs wrote:
| You can, they are just expensive (other than iphone). Maybe 8k
| for a handheld basic one (e.g. Trion P1), $15k for a drone
| attachment (e.g. DJI Zenmuse L1) - more for the ones surveyors
| use proper including the tripod-mount ones.
|
| At the consumer end photogrammetry tends to just be so much
| cheaper that its preferred unless you really need defined
| accuracy at a high level of detail. Lidar tends to work
| currently much better in an industrial/professional context
| because its more accurate. Whether Lidar will make the jump to
| lower cost / consumer level is the big open question (and
| basically the same issue as for cars here)
| brcmthrowaway wrote:
| iphone has actual lidar not photogrammetry right?
| reportingsjr wrote:
| Yes, the iPhone has a laser array and sensor that it uses
| for lidar.
| qiqitori wrote:
| I think this depends on your budget and what exactly you want
| to do. Do you want to scan your house from outside? Sounds
| expensive, would probably have to be drone-mounted, and the
| drone would fly around for a while (depending on the shape of
| the house.) Inside, and don't mind some minor inaccuracies? Not
| Lidar, but a Kinect from yesteryear may be enough.
| tgot wrote:
| Lookup the RPLidar family of devices. Cheap 1D, easy to work
| with. By 1D I mean that it measures ranges in 360degrees around
| the plane that it is spinning in.
| coolspot wrote:
| iPhone pro with LiDAR and Scaniverse or Polycam free apps.
| slt2021 wrote:
| LIDARs can be blinded by consumer grade laser pointers, I wonder
| if there are systems that protect LIDARs against adversarial
| attacks or DOS attacks
| elictronic wrote:
| Drivers can also be blinded by consumer grade laser pointers.
|
| If someone starts attacking safety systems physically I would
| expect they will get quite a bit of jail time.
| rightbyte wrote:
| Messing with machines have a way lower ethical threshold for
| most people.
|
| Like fooling vending machines to give you soda. Nothing 'my
| teenage friend' lost sleep over.
| JumpCrisscross wrote:
| > _Messing with machines have a way lower ethical threshold
| for most people_
|
| We're in the regime of throwing rocks at a freeway from a
| bridge to cutting brake lines as a prank. The attack
| surface here isn't new and isn't difficult to think
| through. Someone who can't is going to be equally
| dangerous, machine or man.
| rightbyte wrote:
| I don't think e.g. 'kids' will see it like cutting a
| brake line.
|
| I agree, as a former ECU programmer, though. I am
| terrified of drive by wire.
|
| More like making the Google computer do silly things.
|
| More comparable would be the prank of tying some soda tin
| cans in a string to the exhaust etc, in how I believe my
| scapegoat kids would see it.
| denysvitali wrote:
| There are also (stupid) people who like to point laser
| pointers to helicopter pilots...
| rightbyte wrote:
| They can be blinded by the sun too.
|
| I worked as a reaserch engineer at a uni playing with a 16 beam
| Velodyne when those were fancy.
|
| Put it on a car for a demo day, drawing the dots in 3d and
| marking obstacles red, and during sun set there was artifacts
| with no obvious way to filter out.
|
| Strangely, I was never able to recreate this. I think was some
| specific athmospheric condition.
| synthos wrote:
| I worked on an automotive FMCW LiDAR that didn't quite make it to
| market. Cool technology but it was difficult to scale the cost
| down, which is pretty important for automotive. Margins are very
| low in that market
| bastloing wrote:
| Why is lidar so expensive? And still needs to be miniaturized.
| But time should solve those problems, there's enough engineering
| effort.
| kube-system wrote:
| When you're measuring something as precise as the time it takes
| light to bounce off something in front of you, you need really
| precise optics and electronics. Also, automotive lidar is still
| in the realm of low-volume specialty equipment, so there are
| little to no economies of scale in manufacturing this stuff.
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