3 ms·
Is the idea here to accurately track the acceleration that the sensor is undergoing? So, if you started at a known location with velocity=0 and integrate the ac
by tomtom1337 2y ago
Is the idea here to accurately track the acceleration that the sensor is undergoing? So, if you started at a known location with velocity=0 and integrate the acceleration data wrt time twice, you get the relative change in position and can thus know your new location?
- Someone 2y agoLooks like it, given (FTA): “The aim of the Imperial College project […] is to create a device that […] does not rely on receiving external signals.” and “At the heart of the quantum compass – which could be ready for widespread use in a few years – is a device known as an accelerometer that can measure how an object’s velocity changes” So, it’s advanced dead reckoning (https://en.wikipedia.org/wiki/Dead_reckoning https://en.wikipedia.org/wiki/Dead_reckoning). I wonder whether they really don’t use external signals at all or occasionally use them to correct for accumulation of errors. For example, the ability to detect that velocity w.r.t. earth is zero would help with that. (Of course, for the London subway, the fact that trains tend to follow the tracks can help, if the system knows the track layout. That probably is the simplest way to prevent accumulation of errors, but then, do they really need such a complex accelerometer?)
- haiku2077 2y agoThey're just using the subway as a convenient moving lab. The real-world application of this technology is for military submarines and marine drones.
- gus_massa 2y agoMy guess is that calculating the initial velocity is hard, so it will drift slowly. Perhapa keep the device on a table for a minute to ensure v=0, or sync it at every subway stop.