Angular Velocity Sensor Rotational Vibration Attenuation
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Solution Overview
Problem
Existing angular velocity sensors fail to effectively suppress output fluctuations due to rotational vibration around the detection axis, particularly when the rotational vibration frequency is near the detuning frequency, leading to signal saturation and reduced detection accuracy.
Innovation Solution
The angular velocity sensor is designed with a resonance frequency in the rotational vibration mode set lower than the detuning frequency, using a mechanical low-pass filter mechanism to attenuate rotational vibrations, ensuring the resonance frequency is greater than the detection frequency band width and the detuning frequency is set to maintain an optimal Signal-to-Noise ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the resonance frequency in rotational vibration mode is set lower than the detuning frequency to create a mechanical low-pass filter, then rotational vibration attenuation is improved, but the detection frequency band may be affected
Solution Approach 1:
The patent applies parameter changes by precisely controlling the resonance frequency f2 to be lower than the detuning frequency f3, while ensuring f2 is sufficiently separated from the detection frequency band (f1). This frequency parameter optimization creates a mechanical low-pass filter effect that attenuates rotational vibration without interfering with the detection band, resolving the contradiction between output stability and detection accuracy
Solution Approach 2:
The patent introduces the rotational vibration mode as an intermediary mechanism between the supporting unit and the detection system. By designing this mode with a specific resonance frequency that acts as a mechanical low-pass filter, it mediates the transmission of rotational vibration to the base portion, allowing high-frequency rotational vibration to be attenuated while preserving the detection signal integrity
2Reliability
If the resonance frequency is set to attenuate rotational vibration near the detuning frequency, then the Signal-to-Noise ratio is improved, but the amplification of rotational vibration in the detection frequency band may increase
Solution Approach 1:
The patent applies parameter changes by establishing specific frequency relationships: f2 (rotational vibration resonance) < f3 (detuning frequency), and ensuring f2 is sufficiently lower than the detection frequency band. This parameter optimization ensures that the rotational vibration amplification occurs at a frequency that does not overlap with the detection band, thereby improving the Signal-to-Noise ratio without causing harmful vibration amplification in the detection range
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 configuration effectively suppresses output fluctuations and enhances the Signal-to-Noise ratio by attenuating rotational vibrations, preventing signal saturation and maintaining detection accuracy even when rotational vibration frequencies approach the detuning frequency.
Implementation Method 1
when an angular velocity around a z-axis is applied from the outside in a state where the vibrating body is vibrated (driving vibration) in an x-axis direction, a Coriolis force acts on the vibrating body, and thus the vibrating body is displaced (detection vibration) in a y-axis direction
Implementation Method 2
the resonance frequency f2 in the rotational vibration mode is made smaller than the detuning frequency f3. Thus, when the rotational vibration around the detection axis is received from the outside, it is possible to attenuate the rotational vibration in a frequency band near the detuning frequency f3
Data Source
AI summary
An angular velocity sensor includes fixing units, a base portion, beam portions that support the base portion with respect to the fixing units, driving vibrating arms connected to the base portion, and detection vibrating arms connected to the base portion. When a width of a detection frequency band is set to f1 [Hz], a resonance frequency in a rotational vibration mode in which the base portion rotates and vibrates around a detection axis with respect to the fixing units in association with the deformation of the beam portions is set to f2 [Hz], and a detuning frequency is set to f3 [Hz], the relation of f1<f2<f3 is satisfied.