Design And Research Of Ultrasonic Guided Wave Excitation Signal Generator

The content of this paper is introduction of an important part which is designed for the ultrasonic guided wave experimental platform--ultrasonic guided wave excitation signal generator design, its direct impact on the precision and accuracy of the experiment.This article describes the history of ultrasonic guided waves nondestructive testing technology research progress in two aspects the theoretical study of the progress and research methods. The same time the introduction of this subject is important and major work.For the design of ultrasonic guided wave excitation signal generator, we should do the nature of ultrasonic guided waves further study. The basic theory from ultrasonic guided wave mode selection based on ultrasonic guided wave ultrasonic guided wave dispersion characteristics, wave group velocity and wave phase speed nature study, and we make sure the frequency of wave base on it. In order to the waveform better sensitivity, we use the narrowband excitation signal tone burst signals. Also in order to make the signal sidelobe, the energy is more concentrated in the main lobe, is modulated using the Hanning window function, which determine the waveform of the excitation signal.System hardware design is based on the modal parameters of ultrasonic guided waves such as frequency and waveform. In order to achieve the requirements of the system, the hardware design of the system the microcontroller peripheral interface circuit design the ultrasonic circuit design, the D/A converter, as well as key input with LCD display circuit design; software design includes the main program design, key interrupt handling program design, to display program design, counter programming and so on. This paper introduce the various parts of the hardware by the device selection, performance analysis and circuit elements connected three aspects. And simulation experiments were carried out in the signal synthesizing section, feasible conclusions. Software design includes the main program design process, key interrupt handler design process, the AD9851program design process, programming, counter programming, the procedure can be found in the Appendix.Finally, it is described in the commissioning of the system with the use of the process. From the instrument appearance, LCD monitor, Keyboard notes describe the design.