Study On The Post-processing Method Of Ultrasonic Phased Array Detection System

To ensure the safety of industrial production is the basis of the steady development of modern industry.Ultrasonic nondestructive testing technology as one of the most widely used nondestructive testing technology,plays an important role in the field of industrial safety.Ultrasonic imaging algorithm is an important factor affecting the detection effect of ultrasonic flaw detection system.In this paper,according to the theory of post-processing imaging method applied to phased array inspection system,model and simulate the algorithms,and analyze the imaging effect of post-processing algorithms.Then test imaging effects of these algorithm in 16×64 ultrasonic flaw detection system.The main work of this paper includes the following aspects:First of all,this paper studied the basic theory of ultrasonic flaw detection,including the sound field theory of ultrasonic,the principle of the defect detection and location by ultrasonic flaw detection system.The transverse resolution and vertical resolution of the flaw detection system are discussed.At the same time the traditional ultrasonic imaging algorithms and the principle of imaging algorithm based on data post-processing technique is studied,compared and analyzed the advantages and disadvantages between the imaging algorithms based on data post-processing technique and the traditional algorithms.Secondly,based on the principle of data post-processing imaging algorithm,Synthetic Aperture Focusing Technology,Multi-element Synthetic Aperture Focusing,Full Matrix Capture–Total Focus Method,Multi-element Total Focus Method,and Synthetic Transmit Aperture algorithm were modeled.The raw data of simulation was collected by the Field II sound field simulation software based on MATLAB toolkit and obtained the imaging results of the above five kinds of algorithms.Beamforming of the above five kinds of algorithm were simulated and combined with the simulation results qualitatively analyzed the imaging quality of the above five kinds of algorithm.Combined with the-6 dB array performance indicator of imaging results quantitatively analyzed the imaging quality of the algorithms.Finally,studied the structure and working procedure of 16×64 ultrasonic flaw detection system,combined with the established model of imaging algorithms,designed a set of data collection process adapting to16 x 64 system.The original experimental data of these five imaging algorithms were collected and processed by median filter method to deal with the baseline drift.Combined with the model of imaging algorithm,the image of the five algorithm were got by process the backward-wave data,and the imaging effect were compared and analyzed.