Silicon Sensing MEMS gyros are Vibrating Structure gyroscopes (VSGs). These VSGs use shell (cylinder or ring) structures and work on the Coriolis forces where forces are observed when linear motion occurs in a rotating frame. The mechanics of the vibrations in a stationary mode and a dynamic mode are shown on the following pages.
The shell structures are very rugged in design and construction. This has the advantage of a superior performance, particularly in a high vibration environment, than competing technologies (eg tuning forks).
The technology provides excellent scale factor and performance over wide rate and temperature ranges.
VSG1 - Launched 1985. Piezo ceramic cup structure provided very low noise gyros but at a relatively high price. All products now obsolete
VSG2- Launched 1995. Metal Ring structure developed to reduce costs. All products now obsolete
VSG3 - Launched 1998. First Silicon MEMS gyro with inductive drive and pick-offs provides a reliable product still in production. Over 20 million parts supplied. Used in CRS03, CRS07, CRS09, CRS39 and SiRRS01.
VSG5 - Launched 2010. Silicon MEMS structure with piezo drive and pick-offs. Low cost/high performance solution. Over 1 million units supplied since launch. Used in PinPoint®, CRM100 & CRM200 and Orion™.