An Advanced Imaging Method Based on Phased Array in NDT

摘要

Nowadays, the conventional Delay-And-Sum (DAS) imaging techniques has been implemented widely on commercial Linear Phased Array (LPA) products in NDT industry. It produces the satisfied image quality but at the cost of significant number of front-end channels. In this paper a novel beamforming imaging method was proposed aiming to provide customers the optimal and cost effective UT imaging instrument, which is capable of producing the satisfied imaging quality in terms of high contrast, high clarify and good resolution but with a small-scale array and less number of front-end channel. An adaptive coherent weighting strategy was proposed along with a synthesis fixed focus transmitting and dynamic receive focusing scheme. The performance of the new techniques was evaluated through simulation and the real experimental data. The results showed that the proposed new method can significantly reduce the front-end hardware complexity while produced satisfactory quality imaging. It can also effectively suppress unwanted interference from undesired directions which are inherently introduced by high-level side-lobe in the beam profile pattern of small-size arrays.