Dual axis operation of a micromachined rate gyroscope

Since micromachining technology hs raised the prospect of fabricating high performance sensors without the associated high cost and large size, many researchers have investigated micromachined rate gyroscopes. The vast majority of research has focused on single input axis rate gyroscopes, but this paper presents work on a dual input axis micromachined rate gyroscope. The key to successful simultaneous dual axis operation is the quad symmetry of the circular oscillating rotor design. Untuned gyroscopes with mismatched modes yielded random walk as low as 10/spl deg///spl radic/(Hour) with cross axis sensitivity ranging from 3% to 16%. Subsequent mode frequency matching via electrostatic tuning allowed performance of 2/spl deg///spl radic/(Hour), but at the expense of excessive cross axis sensitivity.