Research On Characteristics Measurement System Of Ultrasonic Transducer Based On STM32

Ultrasonic testing technology has advantages of high-degree automation and no pollution.The technology of ultrasonic will be the developing direction of precision inspection technology ?Ultrasonic transducer is the key component of ultrasound equipment and its performance has a great influence on the effectiveness and stability of ultrasound equipment.Therefore,it is of great practical significance to research on the system to judge the critical characteristics of the ultrasonic wave to achieve the performance of the transducer.Now there is no standard strain on the different ultrasonic transducer evaluation.It has been judged by experience for a long time.This project focuses on the research of ultrasonic testing ultrasonic transducer's detection performance.Refer to similar measurement experiments using the maximum amplitude,average amplitude and phase difference as the ultrasonic transducer characteristic measurement index,and supply a reasonable standard on quality classification.First analyze the essential characteristics of ultrasonic and the universal evaluation standard of transducer.According to the characteristics of the transducer and the corresponding performance evaluation index of this subject,analyze the advantages and disadvantages of the existing measurement principle of multiple amplitudes and phase differences,and choose suitable for this topic.The measurement principle and formulate the corresponding measurement system program.STM32F407 is selected as the core controller to perform analog-to-digital conversion on the signal-conditioned ultrasonic echo signal with its built-in letter high-speed A/D converter.Verilog hardware description language is used to realize the data collection,data buff and data pretreatment control.Design corresponding echo rectification and low-pass filter circuits to amplify and filter ultrasonic echo signals.The system takes advantages of high speed serial transmission,simple transmission protocol,and strong versatility.RS485 interface chip SP3485 is used as the main core to realize high speed data transmission between the STM32F407 and PC.The host application design is completed in the Lab VIEW development environment to implement data processing and calculation.Finally,the corresponding ultrasonic signal de-noising algorithm is studied.The simulation analysis of the studied algorithm is implemented in MATLAB software.It is proved that the de-noising algorithm used is feasible and the accuracy of the measured parameter is improved.Compare the measured data of the design measurement system of this project with the measurement data of standard equipment and methods,and verify the stability of the measurement system through actual measurements under laboratory conditions.Through the detection of the same batch of transducers,it is verified that the measurement system can realize accurate measurement of the amplitude and phase difference of the echo signals of the transducer.By judging the performance of the ultrasonic transducer,the quality of the ultrasonic transducer can be better verified.