Design Of Ultrasonic Detection Module Based On Time Of Flight Diffraction

Nondestructive detection is an important means to ensure the safety of industrial production.In many nondestructive detection techniques,ultrasonic detection has become one of the most widely used means because of its advantages of large detection depth,high sensitivity,low cost and harmless to human body.In this paper,the ultrasonic detection technology based on time of flight diffraction method is researched,and the detection principle and application requirements are deeply studied.The design of hardware circuit and control program are completed,and then the design result is tested and analyzed with testing software.The main work of this paper includes the following aspects:Firstly,the basic principles,probe characteristics and detection methods of time of flight diffraction ultrasonic detection are deeply studied.The quantitative calculation methods of defect size and depth by using echo signal characteristics are discussed.The scanning and imaging methods of ultrasonic TOFD detection are also briefly introduced,and the limitations of ultrasonic TOFD detection are enumerated.Secondly,the basic structure of ultrasonic TOFD detection system is discussed,and then the overall design of the detection module is proposed according to the ultrasonic nondestructive detection industry standard.Then the chip selection and schematic design of the hardware circuit are completed,and the design of the circuit board is realized by combining the concepts of signal integrity and power integrity.On the basis of the completion of the hardware circuit design,the logic design of FPGA is divided into functional modules,and the function of each functional module are clarifed,and then the design process of USB communication,process control and digital filter are introduced in detail.Finally,the testing software is developed to test the performance of the design results,including USB stable transmission rate test and a number of electrical performance index tests.The testing process and evaluation method of each index are recorded in detail,and the reason analysis of the poor performance indexes are carried out after the test is completed,furthermore some feasible improvement schemes are proposed.The test results show that the performance of the ultrasonic TOFD detection module designed in this paper meets the industry standards and has research and application value.