Vibrating Micro-Mechanical Sensor Multi-Axis Angular Velocity

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Solution Overview

Problem

Existing angular velocity sensors face challenges in measuring multiple degrees of freedom efficiently and cost-effectively, particularly in small vibrating micro-mechanical solutions, while also being sensitive to external mechanical interference.

Innovation Solution

A vibrating micro-mechanical sensor design featuring at least two seismic masses, supported by spring structures and excitation frames, utilizing common primary mode vibrations to measure angular velocity in two or three axes, with differential detection to minimize external interference, and implemented using SOI wafer material for enhanced performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If separate sensors are used for each axis of angular velocity measurement, then measurement precision is improved, but device complexity increases and cost rises

Engineering Contradiction:
Improveangular velocity measurement precisionVSAvoidsensor structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines multiple seismic masses (first and second seismic masses) into a single integrated sensor structure that can measure angular velocity around multiple axes simultaneously. The masses are coupled through spring structures to a common support, allowing one device to perform functions that would traditionally require separate sensors for each axis.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The sensor structure is designed with universal functionality to measure angular velocity around at least two different axes using a common excitation frame and detection system. The first and second seismic masses can both be excited by the same excitation frame and detected by the same detection comb structures, enabling multi-axis measurement with a single device.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If multiple seismic masses are used to measure multiple degrees of freedom, then measurement capability is improved, but space requirements increase

Engineering Contradiction:
Improvedegrees of freedom measurement capabilityVSAvoidsensor footprint area
Core Design Contradiction:
Adaptability or versatilityVSArea of moving object

Solution Approach 1:

The patent employs a nested arrangement where the first and second seismic masses are positioned in different spatial planes (e.g., one in the X-Z plane and another in the Y-Z plane), allowing them to share common support structures and excitation/detection mechanisms. This nesting approach enables multi-degree-of-freedom measurement while minimizing the overall footprint of the sensor.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The invention utilizes three-dimensional spatial arrangement by positioning seismic masses in different planes and orientations. The masses are coupled through spring structures that allow motion in multiple dimensions, enabling the sensor to measure angular velocity around multiple axes without requiring proportional increases in planar footprint area.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Ease of manufacture

If traditional sensor structures are used, then manufacturing simplicity is maintained, but resistance to external mechanical interference deteriorates

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidresistance to shaking and impact
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent segments the sensor structure into distinct functional components: excitation frame, detection frame, spring structures, and seismic masses. This segmentation allows each component to be optimized for its specific function while maintaining overall structural integrity. The modular design facilitates manufacturing while the distributed structure provides resistance to external mechanical interference through differential measurement capabilities.

Inventive Principle:
Principle #1Segmentation

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 design achieves reliable and cost-effective measurement in multiple degrees of freedom with reduced sensitivity to external mechanical interference, enabling efficient use of space and improved signal detection.

Implementation Method 1

at least two seismic masses, which are supported by means of spring structures

Methodology Applied
Scientific EffectSpring: Spring

Implementation Method 2

the at least two seismic masses are adapted to be activated into a common primary mode vibration

Methodology Applied
Scientific EffectVibration: Vibration

Implementation Method 3

An external angular velocity affecting the sensor in a direction perpendicular to the direction of motion of the resonators causes Coriolis forces influencing the masses in opposite directions

Methodology Applied
Scientific EffectCoriolis force: Coriolis Force

Implementation Method 4

The generated vibrations can be capacitively detected by means of the electrodes 18

Methodology Applied
Scientific EffectVibration detection: Vibration

Data Source

PatentEP2269001B1Vibrating micro-mechanical sensor of angular velocity
Publication Date: 2016.11.30 MURATA ELECTRONICS OY
  • EP2269001B1 patent drawingFigure 1
  • EP2269001B1 patent drawingFigure 2
  • EP2269001B1 patent drawingFigure 3

AI summary

The invention relates to measuring devices used in measuring angular velocity and, more precisely, to vibrating micro-mechanical sensors of angular velocity. The sensor of angular velocity according to the invention is adapted to measure angular velocity in relation to two or three axes, and at the least two seismic masses (34-36, 52-53, 71-75) of the sensor of angular velocity are adapted to be activated into primary motion vibration by means of a common mode. The structure of the sensor of angular velocity according to the invention enables reliable measuring with good performance, particularly in small size vibrating micro-mechanical sensors of angular velocity.