Non-contact acoustic diagnostic apparatus for structural deterioration
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Solution Overview
Problem
Existing diagnostic methods for structural deterioration, such as in buildings or infrastructure, often rely on contact-based techniques that may not achieve the same level of diagnostic accuracy as hammering sound evaluations and can be prone to damage and operator variability.
Innovation Solution
A non-contact diagnostic apparatus that uses an excitation unit to radiate an excitation sound to a measurement object, with sound reception units to capture vibration radiation sounds and excitation sounds. The apparatus calculates impulse responses and correlation transfer functions to diagnose the object based on changes in the vibration radiation sound volume as the excitation sound volume changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If contact-based diagnostic methods (ultrasonic waves, acoustic emission sensors, magnetic sensors) are used, then automatic diagnosis is achieved, but diagnostic accuracy is lower than hammering sound evaluations
Solution Approach 1:
The patent replaces contact-based mechanical sensing systems (ultrasonic waves, acoustic emission sensors, magnetic sensors) with a non-contact acoustic radiation pressure measurement system. The excitation unit generates acoustic waves that exert radiation pressure on the measurement object, and the acoustic wave detector measures the resulting vibrations without physical contact, thereby maintaining automation while achieving hammering-sound-level diagnostic accuracy through non-contact acoustic coupling.
2Ease of operation
If contact-based diagnostic methods are used, then diagnosis can be performed, but risk of damage to the measurement object increases
Solution Approach 1:
The patent introduces acoustic waves as an intermediary medium between the excitation unit and the measurement object. Instead of direct mechanical contact, the acoustic waves transmit energy through the air gap, exerting radiation pressure on the object's surface. This intermediary approach enables diagnosis performance while eliminating the direct mechanical contact that causes damage risk.
3Measurement precision
If hammering sound evaluation is used, then high diagnostic accuracy is achieved, but contact with the object is required
Solution Approach 1:
The patent substitutes the mechanical hammering system with a non-contact acoustic radiation pressure system. The excitation unit generates acoustic waves that couple with the measurement object through air, eliminating the need for physical contact while reproducing the diagnostic accuracy of hammering sounds through acoustic-structure interaction.
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 solution enables diagnostic accuracy comparable to hammering sound evaluations while avoiding contact, thus reducing the risk of damage and improving uniformity and accuracy of the diagnosis.
Implementation Method 1
an excitation unit, a first sound reception unit, a second sound reception unit, and a processor. The excitation unit radiates an excitation sound to a measurement object
Implementation Method 2
receives a sound including a vibration radiation sound of the measurement object caused by radiation of the excitation sound
Implementation Method 3
The first sound reception unit is arranged in a vicinity of the measurement object and receives a sound including a vibration radiation sound
Implementation Method 4
The processor calculates a first reference impulse response, a second reference impulse response, a first evaluation impulse response, and a second evaluation impulse response
Data Source
AI summary
A diagnostic apparatus includes an excitation unit, a first sound reception unit, a second sound reception unit, and a processor. The processor designates a plurality of various volumes for the excitation unit. The processor calculates a first reference impulse response, a second reference impulse response, a first evaluation impulse response, and a second evaluation impulse response. The processor calculates a correlation transfer function. The processor calculates a difference between a first evaluation characteristic and a first reference characteristic. The processor diagnoses a measurement object based on the difference and a characteristic that a volume of a vibration radiation sound shifts from a dead zone to a rise region to a linear region to a saturation zone in this order as a volume of the excitation sound changes.