| Electronics > Projects, Designs, and Technical Stuff |
| Are accurate clocks really the limiting factor in cheap Inertial Navigation? |
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| tomato:
--- Quote from: rs20 on March 26, 2019, 02:34:28 am --- The problem is, read what you bolded. The first bottleneck. That implies that this innovation is immediately applicable and useful on its own. --- End quote --- I don't follow that logic. --- Quote ---Regardless, even if you interpret that sentence differently, the entire original article gives absolutely no hint that there's another entirely new innovation required to provide the claimed benefits. It's essentially one group claiming the credit for hypothetical future work done by someone else. --- End quote --- I don't see them trying to take credit for anything other than the advances they've made with small clocks. --- Quote ---Keep in mind that if you had a choice between getting the atomic clock in your phone OR this hypothetical quantum gyro made by someone else; based on what I'm seeing in this thread, you'd absolutely want the quantum gyro. The MEMS sensors are the first bottleneck, not the clock. Hence your bolded sentence is factually wrong. --- End quote --- The authors aren't trying to convert an existing iPhone to an inertial guidance device. The MEMS sensors aren't the main bottleneck because better technology exists. |
| rs20:
--- Quote from: tomato on March 26, 2019, 02:57:20 am --- --- Quote from: rs20 on March 26, 2019, 02:34:28 am --- The problem is, read what you bolded. The first bottleneck. That implies that this innovation is immediately applicable and useful on its own. --- End quote --- I don't follow that logic. --- End quote --- So what does the word "first" mean in this context then? She also says "research by our colleagues on quantum gyroscopes should make this thing even better". If the quantum gyroscope makes it even better, then that implies that this innovation is useful on its own. If I really have to spell it out for you: * "Thing A improves performance by 200%. Thing B makes it even better!" <-- Second sentence makes sense. * "Thing A isn't immediately applicable or useful on its own. Thing B makes it even better!" <-- Second sentence makes no sense whatsoever. Ergo, by contradiction, the sentence "Thing B makes it even better!" implies that the thing mentioned before hand is applicable or useful on its own. --- Quote from: tomato on March 26, 2019, 02:57:20 am --- --- Quote ---Regardless, even if you interpret that sentence differently, the entire original article gives absolutely no hint that there's another entirely new innovation required to provide the claimed benefits. It's essentially one group claiming the credit for hypothetical future work done by someone else. --- End quote --- I don't see them trying to take credit for anything other than the advances they've made with small clocks. --- End quote --- Dude, they're saying "now ambulances can navigate in tunnels and we don't need satellite signals anymore". If they're not claiming the credit for those improvements, are they just rambling irrelevant BS then? --- Quote from: tomato on March 26, 2019, 02:57:20 am --- --- Quote ---Keep in mind that if you had a choice between getting the atomic clock in your phone OR this hypothetical quantum gyro made by someone else; based on what I'm seeing in this thread, you'd absolutely want the quantum gyro. The MEMS sensors are the first bottleneck, not the clock. Hence your bolded sentence is factually wrong. --- End quote --- The authors aren't trying to convert an existing iPhone to an inertial guidance device. The MEMS sensors aren't the main bottleneck because better technology exists. --- End quote --- So go on then, tell me a angular rate sensor that is more accurate than MEMS, and affordable and small enough to fit in a mobile phone? Answering THAT question is the FIRST bottleneck, not clocks. |
| tomato:
--- Quote from: rs20 on March 26, 2019, 03:22:08 am ---So what does the word "first" mean in this context then? She also says "research by our colleagues on quantum gyroscopes should make this thing even better". If the quantum gyroscope makes it even better, then that implies that this innovation is useful on its own. If I really have to spell it out for you: * "Thing A improves performance by 200%. Thing B makes it even better!" <-- Second sentence makes sense. * "Thing A isn't immediately applicable or useful on its own. Thing B makes it even better!" <-- Second sentence makes no sense whatsoever. Ergo, by contradiction, the sentence "Thing B makes it even better!" implies that the thing mentioned before hand is applicable or useful on its own. --- End quote --- When one states Thing A is the first bottleneck, it (generally) means there are several bottlenecks, but Thing A is presently setting the limit for performance. When the authors state "research by our colleagues on quantum gyroscopes should make this thing even better" it likely means that recent advances in quantum gyroscopes have improved their performance, i.e the limits imposed by the second (or third?) bottleneck has become even less of an issue. --- Quote from: rs20 on March 26, 2019, 03:22:08 am ---Dude, they're saying "now ambulances can navigate in tunnels and we don't need satellite signals anymore". If they're not claiming the credit for those improvements, are they just rambling irrelevant BS then? --- End quote --- There is nothing in that sentence that indicates the authors are claiming credit for everything. In fact, they have explicitly praised their colleagues for improvements in the quantum gyros. --- Quote from: rs20 on March 26, 2019, 03:22:08 am ---So go on then, tell me a angular rate sensor that is more accurate than MEMS, and affordable and small enough to fit in a mobile phone? Answering THAT question is the FIRST bottleneck, not clocks. --- End quote --- The whole point of the article is that, with their breakthrough, the clock will no longer be the first bottleneck. Replacing the MEMS may take over the position of first bottleneck. |
| rs20:
OK, but the fact appears to be that even before any of the mentioned advances, quartz crystals are NOT the bottleneck. I repeat, the clock already isn't the first bottleneck. The MEMS sensors have been the bottleneck all along. So if you get the impression from the article that quartz crystals used to be the bottleneck, but due to their breakthrough, MEMS sensors are the new bottleneck, then you've been duped by the dishonesty of the article. It is this dishonesty, along with the implication in the original article that their advance makes satellite-less INS feasible, that I'm questioning in this thread. I mean, looking back at the article, I see they're using words like "one step closer" in various places. So maybe my objection wouldn't hold up in a strictly technical court of law. But that doesn't make it any less slimy or clickbaity. Also, "without the need for satellite signal" is a bloody great stretch given that even the best INS's need occasional feedback, which is almost always from GPS satellites or star trackers. |
| tomato:
--- Quote from: rs20 on March 26, 2019, 05:00:38 am ---OK, but the fact appears to be that even before any of the mentioned advances, quartz crystals are NOT the bottleneck. I repeat, the clock already isn't the first bottleneck. The MEMS sensors have been the bottleneck all along. So if you get the impression from the article that quartz crystals used to be the bottleneck, but due to their breakthrough, MEMS sensors are the new bottleneck, then you've been duped by the dishonesty of the article. It is this dishonesty, along with the implication in the original article that their advance makes satellite-less INS feasible, that I'm questioning in this thread. I mean, looking back at the article, I see they're using words like "one step closer" in various places. So maybe my objection wouldn't hold up in a strictly technical court of law. But that doesn't make it any less slimy or clickbaity. Also, "without the need for satellite signal" is a bloody great stretch given that even the best INS's need occasional feedback, which is almost always from GPS satellites or star trackers. --- End quote --- This device involves clocks based on optical combs and accelerometers based on atom interferometers. Quartz clocks and MEMS aren't the bottlenecks -- they aren't even in the discussion. |
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