Triaxial Gyroscope Composed of Accurately Positioned Building Blocks Incorporating a Z-Axis Gyroscope

Abstract

We propose a triaxial gyroscope with a mounting structure composed of four non-rectangular building blocks with an inclined face on which a single-axis gyroscope is mounted. The mounting structure is designed considering high inter-axial orthogonality, stress resistance, and redundancy for three-axis angular rate detection in the event of failure. Injection molding and molded interconnected device technologies are used to produce plastic blocks with highly precise faces (face angle error: ±0.05°). A prototype is fabricated using blocks in which a Z-axis gyroscope is incorporated. The blocks are accurately positioned by pressing against an alignment jig. Three-axis test results obtained via a vector operation on the outputs of four Z-axis gyroscopes demonstrate a sensitivity to the applied angular rate of 100% for the main axis and ±0.2% for the other axes. An inter-axial orthogonality error of below 0.1° is also demonstrated. The proposed gyroscope detects the three-axis angular rates with low cross-axis sensitivity and has high inter-axial orthogonality.