Vibrator Element Adjustment Arms for Leakage Vibration Cancellation
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Solution Overview
Problem
Existing angular velocity sensors face challenges in accurately detecting angular velocity due to unintended arm bending during manufacturing, leading to reduced detection accuracy and difficulty in adjusting charge output.
Innovation Solution
The proposed solution involves a vibrator element with an excitation arm, a detection arm, and two adjustment arms, where the output signals of the adjustment arms are out of phase and have different amplitudes to cancel and suppress leakage vibrations, allowing for coarse and fine adjustments to improve detection accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a pair of electrodes of the detection portion is partially removed to adjust charge amount, then detection accuracy can be improved, but adjustment accuracy becomes difficult when adjustment amount is large
Solution Approach 1:
The adjustment portion is divided into multiple segments (first adjustment portion and second adjustment portion) that can be independently adjusted. This segmentation allows for stepwise adjustment of the charge amount, improving both the adjustability range and the precision of the adjustment process.
Solution Approach 2:
Instead of removing a large portion of electrodes at once, the adjustment is performed in partial steps through multiple adjustment portions. This allows for gradual refinement of the charge amount, achieving both large adjustments and high precision through iterative partial actions.
2Adaptability or versatility
If a pair of electrodes of the detection portion is partially removed to increase adjustment range, then more flexibility is achieved, but variation of charge amount relative to removal amount must be made small
Solution Approach 1:
Multiple adjustment portions are provided along the detection arm, each contributing differently to the total charge amount. This segmentation enables a wide adjustment range while maintaining control over charge amount variation, as each segment can be independently optimized.
Solution Approach 2:
Different regions of the detection arm (first adjustment portion vs. second adjustment portion) have different adjustment characteristics. By assigning different functions to different locations, the system achieves both wide adjustment range and fine control over charge amount variation.
3Ease of manufacture
If etching is used to form the tuning fork, then manufacturing is simplified, but unintended arm bending occurs due to etching anisotropy
Solution Approach 1:
Adjustment portions are designed into the structure before final assembly, allowing for preliminary adjustment of the arm's mechanical properties. This preliminary action compensates for the unintended bending caused by etching anisotropy, ensuring accurate arm alignment without requiring perfect etching precision.
Solution Approach 2:
The adjustment mechanism creates a compensatory effect that copies and counteracts the unintended bending. By introducing adjustment portions that can be tuned to produce opposite bending, the system compensates for the etching-induced shape errors.
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 enhances the detection accuracy and sensitivity of angular velocity sensors by effectively suppressing leakage signals and allowing for precise adjustments, leading to improved performance and stability.
Implementation Method 1
a first adjustment vibrating arm and a second adjustment vibrating arm extending from the base portion and vibrating along with excitation vibration of the excitation vibrating arm
Implementation Method 2
an output signal of the first adjustment vibrating arm at least is out of phase with an output signal of leakage vibration of the detection vibrating arm
Implementation Method 3
an excitation portion and a detection portion in which a piezoelectric thin film is interposed between a pair of electrodes
Implementation Method 4
when the angular velocity around an axial line in an extension direction is applied to the arm in this excitation state, the arm of the detection portion is bent by the Coriolis force
Data Source
AI summary
A vibration gyro-element includes a base portion, an excitation vibrating arm and a detection vibrating arm extending from the base portion, and a first adjustment vibrating arm and a second adjustment vibrating arm extending from the base portion and vibrating along with excitation vibration of the excitation vibrating arm, wherein an output signal of the first adjustment vibrating arm at least is out of phase with respect to an output signal of leakage vibration of the detection vibrating arm, and wherein an amplitude of the output signal of the first adjustment vibrating arm is larger than an amplitude of the output signal of the second adjustment vibrating arm.