Three-axis MEMS Gyroscope Decoupling Sense Modes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional three-axis MEMS gyroscopes suffer from coupled sense modes, leading to superposition of errors in angular velocity detection.
Innovation Solution
The proposed three-axis MEMS gyroscope features a substrate with anchor point structures and coupling structures that decouple the sense modes, allowing for anti-phase vibration of mass blocks and independent detection of angular velocities along the X, Y, and Z axes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional three-axis MEMS gyroscope designs are used, then three-axis detection capability is achieved, but sense modes become coupled resulting in superposition of errors
Solution Approach 1:
The sensing unit is divided into four independent mass blocks (first, second, third, and fourth mass blocks) positioned at the corners of the substrate. Each mass block is independently connected to the substrate through separate elastic connection structures, allowing independent vibration detection. This segmentation prevents the coupling of sense modes that occurs in conventional designs with shared mass blocks, thereby eliminating superposition of errors and improving angular velocity detection accuracy for each axis.
2Measurement precision
If mass blocks are used to detect angular velocity, then detection capability is achieved, but displacement of non-moving mass blocks occurs reducing accuracy
Solution Approach 1:
Elastic connection structures serve as intermediaries between the mass blocks and the substrate. These elastic connections allow the mass blocks to remain relatively stationary while still transmitting vibrational signals to the substrate. The elastic structures act as mediators that transmit the Coriolis effect-induced vibrations without requiring large displacements of the mass blocks themselves, thereby reducing measurement errors caused by mass block displacement.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design effectively reduces coupling between motion modes, minimizes orthogonal errors, and enhances bias stability, resulting in improved detection accuracy and reduced displacement of non-moving mass blocks.
Implementation Method 1
When an angular velocity Ω is applied, the MEMS oscillating gyroscope transfers energy and is switched to a sense mode due to the Coriolis effect
Data Source
AI summary
A three-axis MEMS gyroscope includes a substrate, a sensing unit connected with the substrate, and a driving unit driving the sensing unit to move. The substrate includes anchor point structures and coupling structures connected with the anchor point structures. The driving unit includes driving pieces. One ends of each of the driving pieces are elastically connected with an adjacent coupling structure. The sensing unit includes X and Y mass blocks and Z mass blocks. Each of the X and Y mass blocks is arranged in a corresponding avoiding space. The X and Y mass blocks are respectively connected with adjacent coupling structures to form a rectangular frame. The Z mass blocks are connected with the driving pieces and separately arranged on one side of each driving piece away from each anchor point structure. The three-axis MEMS gyroscope is differentially driven, which realizes differential detection and reduces quadrature error.