Application of Phase-Reversal Fresnel Zone Plates for High-Resolution Robotic Ultrasonic Non-Destructive Evaluation

Area of Science:

• * Robotics and Automation
• * Ultrasonic Non-Destructive Testing (NDT)
• * Acoustic Lens Technology

Background:

• * Automated inspection systems using six degrees of freedom robotic manipulators are crucial in NDT.
• * Achieving high-resolution results remains a significant challenge in ultrasonic NDT.
• * Localized coupling devices require precise control over focusing depth.

Purpose of the Study:

• * To investigate the application of Phase-Reversal Fresnel Zone Plates (PRFZPs) for high-resolution ultrasonic NDT.
• * To design and validate a PRFZP for specific experimental conditions.
• * To assess the performance of PRFZPs in terms of resolution and signal-to-noise ratio.

Main Methods:

• * Design of a Phase-Reversal Fresnel Zone Plate tailored for experimental requirements.
• * Finite Element Method (FEM) modeling for efficiency verification.
• * Experimental validation using the designed PRFZP in an ultrasonic NDT setup.

Main Results:

• * The designed PRFZP demonstrated effective high-resolution results acquisition.
• * Relative error in flaw size estimation did not exceed 6%.
• * Signal-to-noise ratio consistently remained above 17.1 dB.

Conclusions:

• * Phase-Reversal Fresnel Zone Plates enable high lateral resolution and signal-to-noise ratio in ultrasonic NDT.
• * PRFZPs allow high-resolution acquisition using a single unfocused transducer.
• * The developed technology is suitable for localized coupling devices in robotic inspection.