Study On Ultrasonic Transducer Measurement System Based On Third-order Equivalent Circuit Mode

With the continuous development of science and technology,ultrasonic testing technology has been more and more widely used in the fields of medical health,industrial testing,transportation and energy security.Ultrasonic,as a key components of ultrasonic testing equipment and other applied ultrasonic technology equipment,plays an important role because the quality of the performance index of ultrasonic transducer directly determines the performance of the whole ultrasonic equipment,while the traditional technical method of measuring the performance of passive device such as ultrasonic transducers has some limitations.Taking the performance index measurement of ultrasonic transducer in engineering application as the research background and In view of the shortcomings of the traditional measuring techniques,this thesis studies the realization of efficiently measuring the impedance and frequency characteristics wirelessly(two key performance indicators)of passive devices like ultrasonic transducer,establish the classification test algorithm model,proposes and builds a system based on the performance index of wirelessly measuring ultrasonic transducer of classified optional test circuit and other passive devices,and passed the verification of the feasibility of the method proposed by experiments.This will be of great significance to the design of the matching circuit of the ultrasonic transducer and to guide the efficient work of ultrasonic equipment.The man research work and innovations completed in this thesis are as follows:1.Explain and summarize common and classic impedance measurement techniques and frequency characteristic measurement techniques and analyze the advantages and disadvantages.Besides,propose and design a system based on the performance index of wirelessly measuring ultrasonic transducer of classified optional test circuit and other passive devices,introduce the hardware and software of the system and describe the overall measurement steps of the system.2.Establish the classified test algorithm model and regard the classified optional test circuit as a channel.Obtain the frequency characteristic function of the circuit under test and the parameters of the passive device under test by means of signal processing.Classification test refers to the measurement that is carried out according to the characteristics of the passive device under test and the parameters of the signal output branch.3.The simulation and physical measurement of a single RLC element,the average error of the measurement result is less than 1.5%,which verifies the accuracy of the algorithm and the necessity of classification test.Translate the ultrasonic transducer into a third-order combinational circuit model and simulate and physically measure the third-order combinational circuit model.Finally,the physical measurement of commonly used piezoelectric ultrasonic transducers,the average error of the measurement result is less than 3%.The good experimental results verify the feasibility and application value of the method described in this thesis.