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Vaccum-chamber quantum sensor device could allow GPS-free navigation
- stopagephobia 5y agoI think a big question is how much $ to make one, AIRS is very good but damn expensive.
- aaaaaaaaaaab 5y agoTLDR; Sandia researches dead reckoning with a new kind of atomic accelerometer and gyroscope. It has nothing to do with avocados, aside from someone comparing the device’s size to that of an avocado, and that was probably the only thing the journalist understood so they went with it…
- tartoran 5y agoI really appreciate the TLDR; Saved me and others quite a bit of time
- FeepingCreature 5y agoYeah this article is very bad.
- gsliepen 5y agoIndeed. Also, the old system apparently "needs thousands of volts of electricity," which is too much for airplanes, despite them heating food with microwave ovens which typically use > 10 kV to drive the klystrons that generate the microwaves.
- pixl97 5y agoI'm guessing they turn off the microwave when things go bad, like engines going offline and reducing total power generation to the aircraft.
- tialaramex 5y agoTo be fair the "thousands of volts of electricity" nonsense is in their own press release not just this fluffy article. It's really hard to get the people writing for a lay audience to actually understand the difference between "Simpler for lay people to understand" and "Simply wrong". This is sort-of fine if you're making a Hollywood movie, but it makes serious research look pretty stupid. Unfortunately the rare person who understands and knows how to communicate this stuff to lay people is probably more valuable as a lecturer or in some management role than writing press releases :/
- dboreham 5y agoPerhaps it is green.
- analog31 5y agoLooks more like the size of an oscillation overthruster.
- deleted 5y ago[deleted]
- yetanother-1 5y agoYes, but how will it determine its position without a reference, I read the article and missed that concept.
- saboot 5y agoI'm also confused by this, does it get set a reference point once? If so what is the accuracy degradation, is it fixed over time or acceleration? If it's updated periodically what does that system look like? Is the advantage that it can manage on its own "offline" for a usable period, unlike GPS which needs an active connection?
- mynegation 5y agoAll great questions, but I suspect the answers are classified.
- saboot 5y agoHere's the press release from Sandia https://www.sandia.gov/labnews/2021/10/22/this-device-could-usher-in-gps-free-navigation/ https://www.sandia.gov/labnews/2021/10/22/this-device-could-... And the published paper it refers to https://avs.scitation.org/doi/10.1116/5.0053885 https://avs.scitation.org/doi/10.1116/5.0053885 And I agree that the answers to my questions are probably not public, this is likely going to be very useful for things that go boom, in addition to a lot of other civilian applications.
- throwawaylinux 5y agoThe reference is your previous position. This is known as dead reckoning.
- Snoozus 5y agoJust like dead reckoning works today, you start from a known point at known attitude and integrate up accelerations and rotations to keep an up to date position. Whenever you can get a GPS signal you use that to reduce the drift. Cheap systems can do this for seconds, 10k$ buys you 15minutes (MEMS), 100k an hour (laser gyro), everything above is under export restrictions and NDAs so noone will tell you what the state of the art is. Looks like with these frozen gasses one can build even better sensors, which will make no difference for civilian use because it will be even more expensive than existing systems and also because we wouldn't be allowed to use it.
- errcorrectcode 5y agoHow is this an improvement over other INS like LRG? INS mechanisms suffer from the same problem: that they only detect linear or rotational acceleration. To reach position, double integration must be performed, which rapidly accumulates error (drift) because velocity and position both have to be maintained to calculate the next position. Disclaimer: Trimble Nav alum
- rjeli 5y agoeven worse, your (single) integrated gyro estimate must then be fed back into your double integrated accel filter to subtract gravity and further compound errors :)
- errcorrectcode 5y agoRelativistic effects suck. GPS has to consider it when determining a fix too.
- snerbles 5y agoWhile I heard that the effect of double integration is bad, attempting it as a student with consumer MEMS devices was quite dramatic. Really underscores the importance of Kalman filters and updates from sensors with fewer derivatives.
- bitwize 5y agoYou mean like... GPS? I used to work on AUVs with inertial navigation, and a Kalman filter accepting input from GPS at the surface and a DVL or similar underwater, as well as the inertial unit, was pretty much standard equipment. The device in the article has to have miraculously low error in order to eliminate the need for GPS.
- errcorrectcode 5y agoMiraculous vaporware hype until proven otherwise. Something working in a lab is vastly different from manufacturable.
- mikewarot 5y agoThe 10kv power supply for an ion pump could be quite small, as the load current is proportional to leakage. The real innovation seems to be offering a small package without the voltage induced by the ion pump possibly effective the rest of the environment. The actual paper itself would make it clear what the real advance is, but it's paywalled. 8(
- fabiotrezzi 5y agoAm I wrong or this is exactly the project the Sheldon and the rest of the team were working on in Big Bang Theory ?
- oatmeal_croc 5y agoThis is exactly what I was thinking.
- dtgriscom 5y agoGee: "titanium metal walls"! "Sapphire windows"! (Not exactly aimed at the technically proficient...)
- dang 5y agoUrl changed from https://asiatimes.com/2021/11/atomic-avocado-could-change-the-way-we-navigate/ https://asiatimes.com/2021/11/atomic-avocado-could-change-th..., which seems to be copying from other sources and mentioning them, but not linking to them. That's a shoddy practice and from a quick look at other submissions like they do it a lot, so I've banned the site. If anyone knows of a better article on this, we can change the URL again.
- avsteele 5y agoThe innovation here appear to be the chamber. (caveat: I still need to read the paper). A few thoughts follow. They are going for a UHV***, probably <1e-10 mbar, but want to do it with a passive pumping design. In an ordinary chamber to get there you'd do a pump down, then bake it to remove the water. Then use an ion pump plus occasional firing of a titanium sublimation pump to remove the hydrogen that leaks in (ion pumps don't work so well for hydrogen at low pressures). They have some expensive chamber that doesn't suffer from these leaks. Still a lot of other work to do though. I see a table full of optics to make the MOT*. Also see a pair of anti-Helmholtz coils for the magnetic field. They could maybe replace those coils (which probably drive a few amps) with permanent magnets (assuming they don't need to switch the fields on and off which I imagine they don't because it can't imagine a pulsed design that wouldn't risk missing data) Passive getters work for a good long time with low leak rates. These you can just buy**. To be honest I'm not sure why you need such a fancy chamber. I'd guess a good NEG pump, a small chamber, and good seals would make you fine for a long time, but I'd need to do the math to be sure. *https://en.wikipedia.org/wiki/Magneto-optical_trap https://en.wikipedia.org/wiki/Magneto-optical_trap **https://www.saesgetters.com/products-functions/products/neg-pumps%26vacuum-solutions https://www.saesgetters.com/products-functions/products/neg-... ***https://en.wikipedia.org/wiki/Ultra-high_vacuum https://en.wikipedia.org/wiki/Ultra-high_vacuum
- kragen 5y agoDoes passive pumping mean a chamber full of baked zeolite or something that's then chilled to adsorb all the gas? I guess I should read the paper too, but I don't have a copy.
- Fronzie 5y agoOr even without the chilling. CRT televisions had zeolite as vacuum pump as well. They kept vacuum for up to decades.
- kragen 5y agoI think CRTs were mostly manufactured using conventional high-vacuum pumps with moving parts or liquids, not sorption pumps. They didn't normally include a pump in the cathode-ray tube itself; the pump stayed at the factory. And I think you're mistaken that the CRTs ever included any zeolite. Perhaps you're confusing zeolites with getters, which react irreversibly with any stray molecules that manage to get into the vacuum?
- dumdumdumdum 5y ago> Using a starting point as a fixed reference and calibrated to the patterns of Earth’s magnetic field, data from a quantum navigation system will give us all the information we need to accurately determine where we are. Why is the Earth's magnetic field important? And isn't that just as easy to "spoof" (if not more) than a GPS signal?
- danielheath 5y agoMagnetic field strength falls off rapidly - a spoofer would be extremely large and heavy to reach even a very short range. It’s not going to work against aircraft.
- Animats 5y agoDARPA has been funding work on better gyros and accelerometers for about 10 years now. MEMS gyros keep getting better. The good ones are down to a few degrees per hour.[1] That IMU/GPS is $3,386.09. Not down to the phone/vacuum cleaner price point yet. This is nowhere near as good as the device described in the parent article, but it's good enough for a lot of applications. If you can get a GPS fix every few minutes, it's good enough for many nav applications. (When we did a DARPA Grand Challenge vehicle in 2005, we had a MEMS gyro with over 10 deg/minute drift. That was too much for the mapping to work properly. We needed < 2 deg/minute for the laser scans to align. Better IMUs were back-ordered due to the Iraq war, and attempting to work around the problem with filters and a magnetic compass were not quite good enough.) [1] https://www.mouser.com/ProductDetail/Parker-LORD/3DMGQ7 https://www.mouser.com/ProductDetail/Parker-LORD/3DMGQ7
- willis936 5y agoGPS is trivial to jam. Any exotic IMU has huge defense implications. Being able to miniaturize it would be a big deal.
- ansgri 5y agoI thought so for a long time, but then learned about spread-spectrum and frequency-hopping (with cryptographically randomized pattern) radio communication techniques which are employed in military-grade communications, and suddenly reliably jamming GPS without jamming literally everything becomes very hard.
- vbezhenar 5y agoI'm literally experiencing GPS jamming when I'm driving my car near president palace. Like one second I'm moving on road and next second I'm jumping to random places few hundred meters away until I passed long enough. Navigator sometimes goes crazy because of that. So at least civilian GPS is possible to jam.
- pfortuny 5y ago
- asimjalis 5y ago“Vaccum” in title should be “vacuum”.
- leptoniscool 5y agoWould this be useful on Mars?
- causi 5y agoArticle seems a little short on numbers. Just how slowly does this drift out of true?
- 01100011 5y agoI would think camera-based navigation would be fairly successful at this point. We can easily store large amounts of image and terrain data, and deep learning based image recognition systems are quite powerful. I would think that by limiting your image search space based on your likely position would make the problem even easier to solve. Terrain based navigation is certainly nothing new(1950s?), so there is probably a large pool of research into it, but I wonder what's been done with recent pattern recognition advances?
- upbeat_general 5y agoThere’s still the issue of compute power required for a lot of the CV algorithms you’d want to use. There’s also the question of what data you are using; Satellite imagery is much harder to match with a ground perspective and ground imagery(e.g street view) is very tedious to collect and keep updated. In areas with unique features (dense urban) localizing to within ~50ft has been demonstrated pretty robustly but more accurate methods of localization are a lot more variable and depend on the datasets, cameras (monocular vs stereo), compute, etc.
- Dunedan 5y ago> I would think camera-based navigation would be fairly successful at this point. We can easily store large amounts of image and terrain data, and deep learning based image recognition systems are quite powerful. Aside from the fact that the amount of data required for that would be orders of magnitudes larger than you can reasonably store, that wouldn't work at all in areas with little terrain features like deserts or the open sea.
- Daniel_sk 5y agoOr just a dense forest.
- upbeat_general 5y agoIt’s certainly conceivable that you could store a compressed representation of the image features. Especially if you’re operating in a more limited environment (e.g. a large metro area), it would be very feasible to only store extracted features from the image data that you could use for matching.
- basicplus2 5y agoThis reminds me of a spacecraft navigation system that employed an almost perfect sphere, that floated inside the centre of chamber that employed a detection system that corrected the spacecrafts direction to keep the sphere in the centre of the chamber. On the drawings it was referred to as the space crafts "consciousness" Unfortunately i cannot find any reference to it anywhere.
- sgtnoodle 5y agoI remember that too. Maybe this? https://en.m.wikipedia.org/wiki/Gravity_Probe_B https://en.m.wikipedia.org/wiki/Gravity_Probe_B
- basicplus2 5y agoThats cool! but not that.. the one I an thinking of used the device for course correction over vast distances
- dogma1138 5y agoSounds like AIRS https://en.m.wikipedia.org/wiki/Advanced_Inertial_Reference_Sphere https://en.m.wikipedia.org/wiki/Advanced_Inertial_Reference_... Basically floating gyros, pretty common design for IMUs.