Research On Phased Array Ultrasonic Testing Technique And The Design Of Hardware System

Under the developing trend of the clean energy, China has also accelerated the development of the new energy such as the natural gas. And the safety testing of pipelines has become a research hotspot. As a new non-destructive testing technology, phased array ultrasonic testing technique has been widely used in the field of industrial safety testing with its unique advantages. It can generate ultrasonic wave by exciting the ultrasonic transducer. If you change the delay rules of the phased array probe flexible, then the ultrasonic beam can be focused at different depths and the different direction. It can achieve defect detection in a certain area by using this technique. Compared with the other non-destructive testing method, phased array ultrasonic technique has many advantages: it can detect a wide range of objects; it can turn the defect of the measured object into a picture; it has the feature of high sensitivity and high accuracy. Because our research on phased array technique stay in infancy, and imported phased array testing equipment is expensive, achieving a mature?independent phased array testing system become a crucial problem. We investigate the mature phased array testing equipment, study the basic theory and the key technologies. Based on these work, we have designed a FPGA-controlled 32-channel phased ultrasonic testing system which can be used to detect the defect of natural gas transportation pipelines.In the beginning of this paper, it gives an introduce on the background of the phased array technology and the current developing status of this technique. There is a general description on the fundamental of the phased array testing technique and its key technologies such as the phased delay. Then the advantages and limitation of the phased array testing technique are listed.The detailed design process of the 32-channel phased array ultrasonic testing hardware system is shown in this paper, including the overall design of the hardware system and the circuit design of each function module. The hardware system has many function module: excitation pulse signal transmission circuit; ultrasonic echo signals isolation and channel selection circuit; signal amplification and analog to digital conversion module; FPGA-based control module and dual DDR 2memory circuit; power management module, et al.The design completed the drawing of the PCB and introduced the issues that we need take our attention in the drawing process. There listed some basic rules and constraints we need to follow when work on the high-speed circuit board layout.After the design of the phased array ultrasonic testing system, some functional verification and testing experiment are carried out. The result show that the phased array testing system is completely meet the requirements. The equipment can detect all the defects in the test piece and the system has the feature of good stability and high efficiency.