Research On Reconstruction Technique For High Frequency Acoustic Field Based On Angular Spectrum Method And Its Visualization

In order to achieve the effective evaluation of high frequency acoustic field to promote the development of non-contacted micro-manipulation technology based on ultrasonic radiation force,combing with National High-Tech R&D Program(863 Program) "The key technology research on three-dimension remote manipulation for micro-components based on ultrasonic radiation force"(2006AA04Z329) and on the basis of discussing the theory of acoustic field reconstruction technology using Angular Spectrum Method(ASM),a high precision reconstrticting technique for high frequency acoustic field was established by solving four key factors which affect the reconstruction accuracy in high frequency acoustic field.Moreover,the acoustic field data obtained from reconstruction were displayed in three-dimension within an intuitive and friendly manner by using the latest research results of visualization in scientific computing technology,and a set of three-dimension high frequency acoustic field measurement and reconstruction system was developed.Finally,the reconstruction experiment for high frequency acoustic field was practiced by means of above system,the experiment results validated the feasibility and efficiency of the method proposed in this dissertation.The detail contents of this dissertation are presented as below:Chapter 1,a survey of the importance about research on reconstruction and visualization technology for high frequency acoustic field was given,the review of current status and future developing trend of high frequency acoustic field reconstruction and visualization technology was summarized,the researching direction of the reconstruction and its visualization technique for high frequency acoustic field were specified,and then the research content of this dissertation was presented and each chapter of this dissertation was arranged.Chapter 2,proposed a reconstruction technique for high frequency acoustic field based on ASM.On the basis of analyzing several key factors including selecting interval and holographical aperture,de-noising and the ill-posedness of inverse problem which affect the reconstruction accuracy in high frequency acoustic field,the corresponding solutions were put forward,and thus the reconstruction accuracy was improved,then the feasibility and efficiency of this technique was validated by reconstruction simulation of several typical high frequency radiation acoustic field.Chapter 3,upon the basis of completing the overall program design of acoustic field visualization technique,research mainly on the preprocessing method of measurement data and key technique of realizing three-dimensional acoustic field visualization software were finished,and a set of three-dimensional acoustic field visualization software system was developed by using Visual C++ mixed programming with MATLAB.Chapter 4,using above research achievement,a system with the ability of multi-point simultaneous measurement,analysis and display based on needle type hydrophone was developed,then the experiment was carried out,and the feasibility and superiority of the technique proposed in this dissertation were validated by comparing the experimental results with the data measured actually in acoustic field.Chapters 5,the main conclusions of this dissertation were summarized and the prospect of the future research on high frequency acoustic field reconstruction technique was put forward.