Vibrating Element Detuning Frequency Adjustment via Displacement Asymmetry

Solution Overview

Problem

Angular velocity sensors face challenges in adjusting the detuning frequency due to a small change in detuning frequency per unit mass, leading to disturbances in the balance of drive and detection vibrating arms, which deteriorates the sensor's characteristics.

Innovation Solution

A vibrating element design where the displacement of the detection vibrating arm is greater than the drive vibrating arm, allowing for increased change in detuning frequency per unit mass by adjusting the mass of either arm, thereby reducing the need for significant changes in mass or shape, thus maintaining sensor balance and sensitivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the mass of the drive vibrating arm or detection vibrating arm is greatly changed to adjust the detuning frequency to a target value, then the detuning frequency can be adjusted, but the balance of the vibrating arm is disturbed and characteristics are deteriorated

Engineering Contradiction:

Improvedetuning frequency adjustmentVSAvoidvibrating arm balance

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The invention applies local quality by making the detection vibrating arm have different displacement characteristics compared to the drive vibrating arm. Specifically, the detection vibrating arm is designed to have greater displacement than the drive vibrating arm when both are subjected to rotation, creating a localized difference in vibration behavior that enables better detuning frequency adjustment without affecting overall balance

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The invention changes the displacement parameter relationship between the detection and drive vibrating arms. By designing the detection vibrating arm to have greater displacement than the drive vibrating arm, the system achieves improved detuning frequency control while maintaining proper balance, resolving the contradiction between frequency adjustment and balance maintenance

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If the mass of the drive vibrating arm or detection vibrating arm is greatly changed to bring the detuning frequency to a target value, then the detuning frequency adjustment is achieved, but significant changes in mass or shape are required which complicates the design

Engineering Contradiction:

Improvedetuning frequency adjustmentVSAvoidmass and shape modification

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The invention applies local quality by making the detection vibrating arm have different displacement characteristics compared to the drive vibrating arm. Specifically, the detection vibrating arm is designed to have greater displacement than the drive vibrating arm when both are subjected to rotation, creating a localized difference in vibration behavior that enables better detuning frequency adjustment without affecting overall balance

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The invention changes the displacement parameter relationship between the detection and drive vibrating arms. By designing the detection vibrating arm to have greater displacement than the drive vibrating arm, the system achieves improved detuning frequency control while maintaining proper balance, resolving the contradiction between frequency adjustment and balance maintenance

Inventive Principle:

Principle #35Parameter changes

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 sensitivity and reliability of angular velocity detection while preventing the deterioration of sensor characteristics by increasing the change in detuning frequency per unit mass, allowing for more precise adjustments without compromising the balance of the vibrating arms.

Implementation Method 1

the drive vibrating arms flexurally vibrate (drive-vibrate) close to or away from each other by energization

Methodology Applied

Scientific EffectFlexural vibration: Vibration

Implementation Method 2

when an angular velocity about a predetermined axis is applied to the angular velocity sensor, the drive vibrating arms flexurally vibrate in opposite directions with the Coriolis force

Methodology Applied

Scientific EffectCoriolis force: Coriolis Force

Implementation Method 3

consequently, the detection vibrating arms flexurally vibrate (detection-vibrate) in opposite directions. With the detection vibrations of the detection vibrating arms, charge is generated at electrodes provided on the detection vibrating arms

Methodology Applied

Scientific EffectFlexural vibration: Vibration

Data Source

PatentUS9581446B2Vibrating element with an increased amount of change in detuning frequency per unit mass, vibrator, electronic apparatus, and moving object

Publication Date: 2017.02.28 SEIKO EPSON CORP

AI summary

A vibrating element includes: drive vibrating arm supported to the base portion and extending in a direction of the second axis; and detection vibrating arm supported to the base portion at a position different from the drive vibrating arm and extending in the direction of the second axis. When the vibrating element is subjected to rotation about the second axis while the drive vibrating arm being reciprocally driven in a direction of the first axis, an amount of displacement of the detection vibrating arm in a direction of the third axis at a position distant from the base portion by a distance y1 along the direction of the second axis is greater than an amount of displacement of the drive vibrating arm in the direction of the third axis at a position distant from the base portion by the distance y1 along the direction of the second axis.