Tube trains could navigate the Underground using the rules of Quantum Physics
1–10 of 83 posts
Re: Tube trains could navigate the Underground using the rules of Quantum Physics
#2The title is more than a bit of a stretch, but interesting none the less.
Re: Tube trains could navigate the Underground using the rules of Quantum Physics
#3I looked into quantum inertial navigation a while ago because I wanted to understand - is it some weird quantum thing where they eliminate all accumulated error or not. As far as I could tell the answer is "not" - it's just a very very precise way of measuring acceleration.
Seems kind of hard to imagine that any accelerometer can be so precise you can use dead reckoning to the centimeter over a long time scale. Especially given how strong acceleration due to gravity is.
Re: Tube trains could navigate the Underground using the rules of Quantum Physics
#4I would have thought a simple device that counts the number of times the wheel has rotated would be vastly simpler and cheaper, and surely accurate to within a few centimeters.
Re: Tube trains could navigate the Underground using the rules of Quantum Physics
#51.25 millions doesn’t even buy you the laser to cool the atom gas.
It’s for sure interesting, but to put this on a train, we will have to solve a few more questions. like for example, how do you operate an optical table on a bumpy metro.
Re: Tube trains could navigate the Underground using the rules of Quantum Physics
#6It's kind of annoying that they don't go into specifics about why this is good. The problem with traditional accelerometers is that the error accumulates, and so even small errors accumulate. The article doesn't really address what makes this different - and in fact I don't think it is different. You're still just measuring acceleration using a sensor and that sensor will have errors that accumulate. So the question is how much better is it?
I would wager that actually this is probably just a way of funnelling money into research around quantum rather than genuinely trying to solve this specific problem. This specific problem sounds like it could be solved for a lot less money using conventional accelerometers in combination with some other local location data (optical sensors for example, you're in a very controlled environment).
Re: Tube trains could navigate the Underground using the rules of Quantum Physics
#7I would have thought a simple device that counts the number of times the wheel has rotated would be vastly simpler and cheaper, and surely accurate to within a few centimeters.
But then they couldn't use the word quantum
Re: Tube trains could navigate the Underground using the rules of Quantum Physics
#8> As long as the vehicle has a known starting point, quantum accelerometers can continue tracking its movement accurately, regardless of what’s happening above the atmosphere.
So this is a much more precise inertial guidance system replacement? If true, I'd expect UK MoD to be involved to the point of making technology a military secret, but clearly it didn't happen.
Re: Tube trains could navigate the Underground using the rules of Quantum Physics
#9I looked into quantum inertial navigation a while ago because I wanted to understand - is it some weird quantum thing where they eliminate all accumulated error or not. As far as I could tell the answer is "not" - it's just a very very precise way of measuring acceleration. Seems kind of hard to imagine that any accelerometer can be so precise you can use dead reckoning to the centimeter over a long time scale. Espec…
It's pretty clear from other articles the answer is not. Although from what I can see it claims to be about 50 times better than conventional methods. One claim is they tracked a plane to within a few hundreds meters for a 300 mile flight. Which is technically impressive but entirely useless for the stated purpose in this article.
Re: Tube trains could navigate the Underground using the rules of Quantum Physics
#10If you have fixed beacons with a known location, couldn't the devices work out their location?
Seems like an engineered solution to rely on "quantum".