Research On High Resolution Sparse Full Focus Ultrasonic Phased Array Imaging Algorithm

In recent years,ultrasonic phased array nondestructive testing technology has attracted more and more attention due to its advantages such as flexible acoustic beam control.Although phased array nondestructive testing technology has many advantages,but each technology has its disadvantages,ultrasonic phased array nondestructive testing technology is no exception.Due to the problems of beamforming technology,ultrasonic phased array full matrix-full focus imaging takes a long time,and the imaging resolution of phased array detection is limited by acoustic diffraction,resulting in low image resolution,the existence of grating lobe,side lobe and artifact problems,these shortcomings limit its application in practical industry.In order to solve these problems,the full matrix-full focus beamforming algorithm of ultrasonic phased array is studied from the beam synthesis technology.Is adopted in this paper,based on the principle of "effective aperture" sparse array design,use the transmitting aperture synthesis method based on adaptive weighted function for full matrix-full focus imaging for sparse array,effectively improve the full matrix-full focus imaging resolution and efficiency,improved the performance of whole focus imaging algorithm,the related research results are as follows:(1)The principle of phased-array traditional time-delay superposition focusing imaging and full matrices full focusing imaging algorithms are studied.Field II is used to carry out simulation and comparison experiments of three imaging algorithms of phased array: traditional time-delay superposition focusing,dynamic focusing and full matrices full focusing.Based on the beam width diagrams of three focusing techniques in phased array beam synthesis,the imaging resolution of the three focusing techniques is analyzed,and the influence of array element directivity function on the imaging quality of full matrices and full focusing is analyzed based on simulation experiments.(2)A phased array sparse synthetic aperture full focus imaging algorithm based on adaptive weighting function is proposed,and the algorithm model is established.Will launch aperture synthesis technology and full matrix-full focus imaging algorithm,improve the imaging resolution,the follow the principle of effective aperture and point scattering function under the sparse array design,thus reducing the imaging data volume,and join the adaptive weighted function,the sparse array with full aperture effect,achieved while maintaining the quality of imaging resolution and speed up the imaging purposes;Field II is used to simulate and analyze the image reconstruction of ultrasonic phased array full matrices and full focus imaging algorithm,phased array sparse synthetic aperture full focus imaging algorithm,and phased array sparse synthetic aperture full focus imaging algorithm based on adaptive weighting function.