MEMS Gyroscope Decoupling Structure for Sensitivity
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Solution Overview
Problem
Traditional MEMS gyroscopes suffer from small drive/detection capacitance and low Coriolis gain, which limits their sensitivity and accuracy.
Innovation Solution
A MEMS gyroscope design featuring internal and external coupling beams, decoupling structures with specific elastic members, and transducers to enhance vibration amplitude and sensitivity, while minimizing quadrature error through orthogonal vibration shaft arrangements and asymmetric mass distribution between drive and detection weights.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional MEMS gyroscope structure is used, then device complexity is low, but sensitivity is poor and quadrature error is high
Solution Approach 1:
The gyroscope structure is segmented into distinct functional modules: drive structure with driving weights, detection structure with testing weights, internal coupling beam, external coupling beam, and decoupling structures. This segmentation allows optimization of each module's function while managing overall complexity through modular design.
Solution Approach 2:
The detection structure is nested within the drive structure, with testing weights positioned inside the drive structure and connected through coupling beams. This nested arrangement maximizes space utilization and enables the detection of Coriolis forces generated by the driving weights.
2Measurement precision
If drive and detection structures are closely coupled, then device complexity is reduced, but quadrature error increases
Solution Approach 1:
Decoupling structures are extracted from the main structure to separate the drive and detection functions. The first decoupling structure connects the drive structure to the external anchor, and the second decoupling structure connects the detection structure to the internal anchor, effectively isolating the two functions to minimize quadrature error.
Solution Approach 2:
Coupling beams serve as intermediaries between the drive and detection structures. The internal coupling beam connects the drive structure to the detection structure, while the external coupling beam provides additional mechanical coupling, enabling force transmission while maintaining functional separation.
3Measurement precision
If symmetric mass distribution is used, then manufacturing is easier, but Coriolis gain is low
Solution Approach 1:
The gyroscope employs asymmetric mass distribution with driving weights having a first mass and testing weights having a second mass, where the masses are deliberately different. This asymmetry optimizes the Coriolis gain by creating unequal inertial effects that enhance the detection signal while remaining compatible with standard fabrication processes.
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
The design improves sensitivity and reduces quadrature error, achieving greater Coriolis gain and vibration amplitude, thereby enhancing the overall performance of the MEMS gyroscope.
Implementation Method 1
a drive structure including multiple driving weights vibrating along a first vibration shaft or a second vibration shaft under a driving mode status
Implementation Method 2
a detection structure alternately arranged on outside of the internal coupling beam, and having multiple testing weights vibrating along a third vibration shaft or a fourth vibration shaft in a detection mode
Implementation Method 3
the internal coupling beam and the external coupling beam both undergo elasticity deformation in the driving/detecting mode
Implementation Method 4
Traditional MEMS gyroscope has shortcomings such as small drive/detection capacitance and low Coriolis gain
Data Source
AI summary
The present invention provides a MEMS gyroscope having internal coupling beam, an external coupling beam, a drive structure and a detection structure. The drive structure includes multiple driving weights, and the detection structure includes multiple testing weights. The drive structure further includes a first decoupling structure and a first transducer. The first decoupling structure is arranged on the side of the driving weight far away from the internal coupling beam, and the first transducer excites the driving weight to vibrate. The MEMS gyroscope of the present invention can fully increase the layout area of the first transducer, thereby realizing a larger vibration amplitude under a small driving voltage, thereby increasing the sensitivity.