Design Of Ultrasonic Phased Array Digital System For Industrial Inspection

Phase Array detection is an advanced ultrasonic detection method widely used in medical imaging and industrial non-destructive testing.Based on the existing 32-channel portable flaw detector,a 64-channel new desktop industrial ultrasonic testing system was designed and implemented.The main work is as follows:1.Study on principle of ultrasonic phased array technology.The theory of ultrasonic sound field,principle of ultrasonic detection and theory of ultrasonic imaging detection were studied.To lay a solid theoretical foundation for the design of the follow-up digital system,the principle of ultrasound emission reception,basic scanning methods,and key imaging indicators were emphatically analyzed.2.Design of ultrasonic phased array digital system.Based on the related ultrasound theory,the requirements of 64-channel new desktop ultrasonic digital system were analyzed.The master-slave digital system architecture was designed and the system protocol formulation and functional module division were completed.The system hardware platform was designed according to the system architecture,including the design of the power supply scheme and high-speed digital circuit simulation.Finally,the FPGA design in the reset design,clock design,cross-clock domain data processing and other aspects of in-depth discussion,help to improve the stability of the subsequent digital system FPGA design.3.FPGA design and implementation of ultrasonic phased array digital system.Based on the scheme of the 64-channel ultrasound digital system design,we first achieved a low-complexity 2.5ns delay accuracy based on the four-phase phase-shifted clock generated by the FPGA's internal PLL.Then through the dual-port RAM buffer ultrasonic echo signal and the corresponding address of the read-write control to complete the signal delay processing,the sum of the processed data can be averaged to achieve sound beam synthesis.Using Matlab simulation to compare the baseline effect of the IIR filter,the median filter and the mean filter,the remove baseline algorithm was implemented using the mean filter.Finally,using CORDIC algorithm,IIR filter and so on in the FPGA to achieve a digital quadrature detection algorithm and a good extraction of the signal envelope.4.Testing and analysis of ultrasonic phased array digital system.Tested and analyzed the 64-channel new desktop industrial ultrasonic testing digital sub-modules.Firstly,the RTL-level functional simulation of FPGA was realized through Modelsim.The real-time working signal of the module was captured by Signaltap for analysis simultaneously.Finally,the signal of the key circuit test point was measured through the oscilloscope and the image received by the host computer shows that the system meet the design requirements and works stably.The research of the above key technologies and the design and implementation of the desktop digital system have significantly improved the performance of the phased-array ultrasound imaging system and lay a solid foundation for the subsequent development of a 128-channel,256-channel desktop industrial inspection system.