Gyro Vibrating Arms Inverse-Phase Vibration Mask Displacement
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Solution Overview
Problem
Existing angular velocity detection gyro elements face issues with noise due to unwanted vibrations in the Z-axis direction, leading to degraded detection accuracy, particularly caused by mask displacement during manufacturing, which results in uneven cross-sectional shapes of drive arms.
Innovation Solution
The proposed solution involves an angular velocity detection element with vibrating arms that vibrate in-phase in the X-axis direction and inverse-phase in the Z-axis direction, utilizing piezoelectric elements to generate signals with opposite phases, which cancel out noise and maintain detection accuracy even with mask displacement, and incorporating a simplified configuration with piezoelectric elements for both drive and detection sections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If photolithography and etching techniques are used to pattern the quartz crystal substrate, then the outer shape of the gyro element can be obtained, but mask displacement occurs causing the cross-sectional shapes of the drive arms to deviate from design shapes
Solution Approach 1:
The patent introduces asymmetric structures (tilted vibrating arms and asymmetric mass distribution) to create a deliberate imbalance that generates a compensating moment. This asymmetric design allows the system to counteract the unwanted effects of mask displacement and achieve the desired vibration mode despite manufacturing inaccuracies.
2Manufacturing precision
If mask displacement occurs during manufacturing, then the cross-sectional shapes of the drive arms become non-uniform, but this causes vibration coupling between Z-axis in-phase mode and X-axis inverse-phase mode
Solution Approach 1:
The patent applies preliminary anti-action by pre-configuring the vibrating arms with specific asymmetric geometries and mass distributions that generate compensating forces. These pre-designed asymmetric features create moments that counteract the coupling effects caused by mask displacement, preventing the unwanted vibration mode coupling before it occurs during operation.
3Measurement precision
If the drive arms vibrate in the X-axis inverse-phase mode, then angular velocity detection is enabled, but unwanted Z-axis vibrations occur due to mode coupling, generating noise
Solution Approach 1:
The patent employs counterweight principles by introducing asymmetric mass distributions and tilted arm configurations that generate opposing moments. These counter-moments balance and cancel out the unwanted Z-axis vibrations caused by mask displacement, eliminating the noise source while preserving the desired X-axis inverse-phase vibration mode for accurate angular velocity detection.
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 approach effectively reduces noise and maintains high detection accuracy by canceling out unwanted vibrations, ensuring reliable angular velocity detection despite manufacturing inaccuracies and mask displacement, resulting in a more robust and accurate angular velocity detection system.
Implementation Method 1
utilizing piezoelectric elements to generate signals with opposite phases
Data Source
AI summary
A gyro element includes a base section, vibrating arms connected to the base section, driving piezoelectric elements disposed on the vibrating arms and causing a flexural vibration in the drive vibration mode of X-axis in-phase and Z-axis inverse-phase, and detecting piezoelectric elements disposed on the vibrating arms and adapted to detect the angular velocity around the detection axis, and in a case of making the vibrating arms flexurally vibrate in the drive vibration mode, signals having respective phases reverse to each other are generated in the detecting piezoelectric elements, and in a case in which the angular velocity is applied while making the vibrating arms flexurally vibrate in the drive vibration mode, signals having respective phases the same as each other are generated in the detecting piezoelectric elements.