A gyroscope smaller than a fingertip could prove the key to accurate navigation without Global Navigation Satellite Systems (GNSS) like GPS — and the University of Michigan claims to have made a highly-accurate version three orders of magnitude cheaper than the current state of the art.
"Our gyroscope is 10,000 times more accurate but only 10 times more expensive than gyroscopes used in your typical cell phones," explains Professor Khalil Najafi of the ultra-compact device. "This gyroscope is 1,000 times less expensive than much larger gyroscopes with similar performance."
Gyroscopes allow for so-called inertial navigation - literally tracking the twists and turns a vehicle or person takes — in place of relying on GNSS systems. Inertial navigation works anywhere, even indoors, but comes with one major drawback: It needs an inertial measurement unit (IMU) built with extremely accurate gyroscopes in order to work, or the small measurement errors quickly compound into a massive loss of accuracy.
"High-performance gyroscopes are a bottleneck, and they have been for a long time," says Jae Yoong Cho, an assistant research scientist in electrical engineering and computer science at the University of Michigan. "This gyroscope can remove this bottleneck by enabling the use of high-precision and low-cost inertial navigation in most autonomous vehicles."
The team's work relies upon a glass resonator, produced from fused silica a quarter of a millimetre thick, surrounded by electrodes and measuring just 1cm (around 0.4") in diameter. "Basically, the glass resonator vibrates in a certain pattern," notes Sajal Singh. "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."
Details of the gyroscope are to be revealed in a paper presented at the 7th IEEE international Symposium on Inertial Sensors & Systems later this week; Enertia Microsystems, meanwhile, has been founded as a startup to exploit the technology and produce a commercial implementation.