Optical Fiber Acoustic Sensing with Adaptive Section Evaluation
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Solution Overview
Problem
Existing optical fiber sensors struggle with low detection accuracy for acoustic signals with amplitudes equal to or smaller than background noise, making it difficult to accurately locate sound sources in wide-area monitoring systems.
Innovation Solution
The optical fiber sensor sets sections of varying lengths for evaluation, extracts state changes in light using time-series data, and employs detection methods to improve accuracy in detecting environmental changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a single optical fiber microphone is used to monitor wide area, then the monitoring coverage is large, but the detection accuracy deteriorates due to low signal-to-noise ratio
Solution Approach 1:
The optical fiber is divided into multiple sections along its length, with each section acting as an independent acoustic sensing unit. This segmentation allows the system to process acoustic signals from different locations separately, improving the ability to detect and locate sound sources while maintaining wide-area coverage.
Solution Approach 2:
The patent transitions from single-point acoustic detection to distributed spatial detection along the optical fiber. By utilizing the longitudinal dimension of the optical fiber and dividing it into multiple sections, the system achieves three-dimensional acoustic field monitoring capability, enabling both wide coverage and precise location identification.
2Measurement precision
If multiple microphone arrays are installed for wide-area monitoring, then the detection accuracy improves, but the construction cost increases
Solution Approach 1:
A single optical fiber sensor performs multiple functions that would traditionally require multiple separate microphone arrays. The optical fiber simultaneously provides wide-area coverage, acoustic signal detection, and spatial location identification, eliminating the need for multiple distributed microphone arrays and reducing system complexity.
Solution Approach 2:
The patent replaces mechanical microphone arrays with an optical fiber-based sensing system. By using optical fiber as the sensing medium and detecting acoustic-induced strain optically, the system eliminates the need for multiple electronic microphones and associated signal processing equipment, thereby reducing construction cost and complexity.
3Reliability
If the section length is increased to improve signal collection, then the signal-to-noise ratio improves, but the location resolution deteriorates
Solution Approach 1:
The optical fiber is divided into multiple discrete sections, each optimized for a balance between signal collection and location resolution. By segmenting the fiber and processing signals from each section independently, the system achieves both sufficient signal-to-noise ratio within each section and precise location resolution through section identification.
Solution Approach 2:
The system dynamically adjusts the evaluation between different section configurations based on detection needs. The optical fiber sensor can adaptively select and evaluate specific sections along the fiber, allowing flexible optimization of the balance between signal collection efficiency and spatial resolution for different monitoring scenarios.
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
Enhances detection performance by accurately identifying sound sources, even at low signal amplitudes, reducing the need for multiple microphones and lowering system costs.
Implementation Method 1
An optical fiber sensor that uses a scattered light by Rayleigh scattering (Rayleigh scattered light)
Implementation Method 2
When a section of an optical fiber is affected by an incoming item (for example, incoming sound or vibration), the optical fiber expands or contracts in the section
Data Source
AI summary
The optical fiber sensor includes a setting unit which sets a section to be evaluated set in the optical fiber to one of a first section and a plurality of second sections, each of which is shorter than the first section, an extraction unit which extracts a state change of light from the optical fiber, and a detection unit which detects a change in the surrounding environment based on time-series data of the state change of light in the section to be evaluated.