Robotic scanning technology for laser pulse‐echo inspection

Abstract

The full‐field pulse‐echo ultrasonic propagation imaging (PE UPI) system using a two‐axis linear stage has been successfully used to perform a non‐destructive evaluation of flat specimens. This study used a six‐axis robot arm to develop a robotic scanning algorithm that can be applied to the laser pulse‐echo inspection of non‐flat objects. The robotic PE UPI system was constructed and verified for both flat and curved specimens. The internal structures and defects of a honeycomb sandwich plate and a glass‐fibre‐reinforced polymer specimen were visualised by the robotic PE UPI system. The quality of the evaluation of the flat specimen was equivalent to that of a two‐axis linear system, and the result of the curved specimen showed improvement compared to that of the linear system. The ability of the robotic scanning technique to evaluate the structural health performance of arbitrarily shaped surfaces was validated.

Robotic scanning free-space measurement system for electromagnetic performance evaluation of curved radar absorbing structures

“…A similar result was obtained by Son et al 24 for S-shaped specimens using two-axis SFM. To conclude, the negative curvature reduces the resonant frequency return loss due to the compression of the outer surface of the specimen, as shown by region A, and the positive curvature increases the resonant frequency return loss due to the expansion of the specimen, as shown by region C. These results show that six-axis RSFM has been applied to EM evaluation as well as non-destructive testing by Lee et al 25 of curvature specimens.…”

Guest Editorial: Non‐Destructive Testing

“…In [20 ], Sikundalapuram et al , present an elastic metamaterial rod for mode filtering in ultrasonic applications. Finally, in [21 ], Lee et al study a six‐axis robot arm to develop a robotic scanning algorithm which can be applied to the laser pulse‐echo inspection of non‐flat objects.…”