New small, precise gyroscope for navigating without GPS

A small, inexpensive and highly accurate gyroscope, developed at the University of Michigan, could help drones and autonomous cars stay on track without a GPS signal. Ιs 10,000 times more accurate and 1,000 times less expensive than much larger gyroscopes with similar performance. [It is 10 times more expensive than gyroscopes used in your typical cell phones].

The device that enables navigation without a consistent orienting signal is called an inertial measurement unit. It is made up of three accelerometers and three gyroscopes, one for each axis in space. But getting a good read on which way you're going with existing IMUs is so pricey that it has been out of range, even for equipment as expensive as autonomous vehicles. The key to making this affordable, small gyroscope is a nearly symmetrical mechanical resonator. It looks like a Bundt pan crossed with a wine glass, made one centimeter wide.

As with wine glasses, the duration of the ringing tone produced when the glass is struck depends on the quality of the glass—but instead of being an aesthetic feature, the ring is crucial to the gyroscope's function. The complete device uses electrodes placed around the glass resonator to push and pull on the glass, making it ring and keeping it going. The glass resonator vibrates in a certain pattern. If you suddenly rotate it, the vibrating pattern wants to stay in its original orientation. So, by monitoring the vibration pattern it is possible to directly measure rotation rate and angle.The way that the vibrating motion moves through the glass reveals when, how fast and by how much the gyroscope spins in space.

The paper, "0.00016 deg/√hr angle random walk (ARW) and 0.0014 deg/hr bias instability (BI) from a 5.2M-Q and 1-cm precision shell integrating (PSI) gyroscope," is scheduled to be presented at the (now virtual) 7th IEEE international Symposium on Inertial Sensors & Systems, on Wednesday, March 25.

Most smartphones contain gyroscopes to detect the orientation of the screen and help figure out which way we're facing, but their accuracy is poor. They're the reason why phones often incorrectly indicate which direction a user is facing during navigation. It doesn't matter much to a human on the street or behind the wheel, but a driverless car could get lost quickly with a loss of GPS signal. Inside their backup navigation systems, autonomous vehicles currently use high-performance gyroscopes that are larger and much more expensive. Better backup navigation equipment could also help soldiers find their way in areas where GPS signals have been jammed. Or in a more mundane scenario, accurate indoor navigation could speed up warehouse robots.

https://techxplore.com/news/2020-03-small-precise-gyroscope-gps.html