---
title: ""The secret to this level of accuracy is the heart of the gyro -- a…"
date: 2020-04-11
source: facebook
type: Archer T. Ships shared a link.
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# "The secret to this level of accuracy is the heart of the gyro -- a…

*April 11, 2020 · Facebook*

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[https://spectrum.ieee.org/tech-talk/sensors/automotive-sensors/new-gyroscope-design-will-help-autonomous-cars-robots-map-world](https://spectrum.ieee.org/tech-talk/sensors/automotive-sensors/new-gyroscope-design-will-help-autonomous-cars-robots-map-world){target="_blank"}
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\"The secret to this level of accuracy is the heart of the gyro \-- a resonating structure of ultra-pure metal-coated glass that looks almost exactly like a upside-down Bundt cake pan, or an upside-down bird bath.\"\
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\"A wine-glass-shaped resonator is much better at measuring rotation than a tuning-fork-shaped resonator for several reasons. First, the shape is axisymmetric, or symmetrical around a central axis. This symmetry means that the two modes of vibration happen at almost the exact same frequency, so when the Coriolis effect transfers energy from the first mode to the second, it\'s very efficient, meaning that you get more vibration per amount of rotation, leading to a more sensitive gyro.\"\
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\"Wine-glass resonators also have a very high \'Q factor,\' which is a dimensionless measurement of the ratio between the amount of energy that\'s stored in a resonator, and how much energy the resonator loses every time it oscillates.\" \"A typical cell phone gyro has a Q of a few hundred and vibrates for much less than a second. The resonator that makes up the core of the PSI gyro has a Q of 5.1 million (!), meaning that once it\'s packaged up in a vacuum it\'ll vibrate for 300 seconds after being whacked one single time. \"
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