Coupled MEMS Proof Mass Structure for Accurate Gyroscope Sensing
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Solution Overview
Problem
Existing MEMS devices fail to effectively separate angular velocity from acceleration signals, which are sensitive to angular rotation, with existing technologies, and existing gyroscopes are sensitive to acceleration, and existing gyroscopes are sensitive to acceleration, which are not easy to achieve efficient and accurate angular rotation measurements.
Innovation Solution
A MEMS device with a first and second proof mass configured to oscillate in anti-phase in a primary direction perpendicular to the y-axis, using flexible and stiff suspension structures, and a first coupling structure that transmits force in the primary direction between the first and second proof masses, with flexible and stiff suspension structures, and a second suspension structure that connects the first and second proof masses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single-mass gyroscope is used, then the device structure is simple, but the measurement precision deteriorates due to sensitivity to acceleration
Solution Approach 1:
The single proof mass is segmented into two separate proof masses (first proof mass and second proof mass) that are coupled together. This segmentation allows the system to distinguish between acceleration effects (which affect both masses equally) and Coriolis effects (which affect masses differently), thereby improving measurement precision while maintaining relatively simple structure.
2Measurement precision
If mass pairs oscillate out-of-phase to suppress acceleration signal, then measurement precision improves, but device complexity increases
Solution Approach 1:
Two proof masses are merged into a single coupled system where the masses are connected through coupling structures. This merging allows the system to achieve differential oscillation modes for suppressing acceleration signals while sharing common support structures and control mechanisms, thus limiting the increase in device complexity.
3Measurement precision
If coupling structures synchronize out-of-phase motion, then measurement precision improves, but cross-axis interference increases
Solution Approach 1:
The coupling structures are designed with directionally dependent properties: they provide strong coupling in the primary oscillation direction (x-direction) to synchronize out-of-phase motion, while providing weak or no coupling in the perpendicular direction (y-direction) to minimize cross-axis interference. This local quality differentiation allows the system to achieve precise measurement while suppressing harmful cross-axis effects.
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 MEMS device achieves efficient and accurate angular rotation measurements by minimizing cross-axis interference and ensuring independent oscillation modes, which are sensitive to acceleration, and the coupling structure that connects the first and second proof masses, with flexible and stiff suspension structures, and a second suspension structure that connects the first and second proof masses.
Implementation Method 1
a first proof mass and a second proof mass in a device plane that is defined by an x-axis and a y-axis that is perpendicular to the x-axis, the first proof mass and second proof mass being configured to oscillate in anti-phase in a primary direction that is perpendicular to the y-axis
Implementation Method 2
a first y-axis spring structure that is more flexible in the y-direction than in the primary direction
Implementation Method 3
a first primary spring structure that is more flexible in the primary direction than in the y-direction
Implementation Method 4
the other oscillation mode (the secondary oscillation mode) is generated by the Coriolis force when the gyroscope undergoes rotation
Data Source
AI summary
A microelectromechanical device is provided that includes a first proof mass and a second proof mass. A first coupling structure is configured to transmit force in a primary direction between the first and second proof masses. The first coupling structure is connected to a primary spring structure in a first suspension structure that extends from a first anchor point to the first proof mass. The first primary spring structure is more flexible in the primary direction than in the y-direction.