Adaptive Ultrasonic Flaw Imaging With Misalignment Compensation
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Solution Overview
Problem
Existing ultrasonic inspection methods for detecting subsurface flaws in structures face challenges such as misalignment between the probe assembly and the test specimen, leading to flawed imaging and suppressed flaw identification, particularly in volumetric scans.
Innovation Solution
An adaptive approach using zonal Dynamic Depth Focusing (zDDF) and Coherent Adaptive Focusing (CAF) techniques to compensate for misalignment by applying delay factor corrections, allowing for accurate imaging of flaws through virtual probe generation and coherent summation of acoustic echo signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional ultrasonic inspection methods are used with fixed probe positioning, then the inspection process is simple to operate, but misalignment between the probe assembly and the test specimen causes flawed imaging and suppressed flaw identification
Solution Approach 1:
The system performs preliminary characterization of the test specimen surface geometry using the same transducer array before conducting the actual flaw detection. This preliminary action captures surface variation data that is then used to pre-calculate compensation delay values, allowing the main inspection to proceed without requiring precise manual alignment while maintaining high measurement precision
Solution Approach 2:
The patent dynamically adjusts the delay values applied to signals from different transducer elements based on the measured surface geometry. By changing these temporal parameters in response to measured surface variations, the system compensates for misalignment and maintains accurate flaw detection even when probe positioning varies
2Area of stationary object
If volumetric scanning with stacked E-Scan images is performed, then coverage of the inspection area is improved, but the imaging does not represent flaw location corresponding to actual physical location
Solution Approach 1:
The patent replaces the mechanical stacking approach with a computational field-based reconstruction method. Instead of mechanically moving the probe and stacking images, the system uses phased array transducers to illuminate the entire volume and reconstructs the flaw locations using delay-and-sum beamforming with surface-compensated delay values, achieving both full coverage and accurate spatial representation
Solution Approach 2:
The system transitions from 2D E-Scan image stacking to 3D volumetric reconstruction by utilizing the full phased array capability to probe multiple depths and angles simultaneously. The surface compensation technique adds a spatial dimension correction that maps reconstructed flaw positions back to their true physical locations in three-dimensional space
3Reliability
If delay factor corrections are applied to compensate for surface variation, then flaw detection sensitivity is enhanced, but the processing complexity increases
Solution Approach 1:
The surface characterization and delay value calculation are performed as a preliminary step before the actual flaw detection scan. By pre-computing the compensation delays based on measured surface geometry, the system enhances detection sensitivity without adding complexity to the time-critical inspection process itself
Solution Approach 2:
The system implements dynamic delay adjustment where the compensation values are calculated based on actual measured surface conditions rather than using fixed predetermined values. This dynamic adaptation optimizes detection sensitivity for each specific inspection scenario while maintaining efficient processing through algorithmic automation
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 inspection productivity and sensitivity to flaws while reducing the impact of mechanical misalignment, providing intuitive and accurate imaging of subsurface defects.
Implementation Method 1
generating respective acoustic transmission events using different transmitting apertures, the apertures defined by corresponding zones along the array, the zones include multiple electro-acoustic transducer elements
Implementation Method 2
In response to the respective acoustic transmission events, respective acoustic echo signals are received, using receiving ones of the electro-acoustic transducer elements
Implementation Method 3
acoustic (e.g., ultrasonic) inspection can be used to obtain data for imaging of features on or within a test specimen
Data Source
Figure 1
Figure 2A~2B
Figure 3A~3B
AI summary
Acoustic evaluation of a target can be performed using an array of electro-acoustic transducers. For example, a technique for such evaluation can include generating acoustic transmission events using different transmitting apertures, the apertures defined by corresponding zones along the array, the zones including multiple electro-acoustic transducer elements. In response to the respective acoustic transmission events, respective acoustic echo signals are received. Representations of the respective received acoustic echo signals are coherently summed. The coherently summing includes applying determined nominal element delay factors to the respective representations to approximate a virtual probe normal to a nominal shape of a surface of a structure being inspected. A pixel or voxel value is corresponding to a specified spatial location within the structure being inspected is generated using the coherently summed representations.