The Sound Field Simulation And The Research On Experimental System Of Phased Array Technology

Compared with traditional Ultrasonic Testing,the ultrasonic phased array can control its acoustic angle, focus range and focus size by software ; Operates simply, can realize Multi-angle-scan only use poly probe which control by a small electronic; have very flexibility on the test of complex geometry materials. So Phased Array Technology plays an important role in Nondestructive Testing. The sound field directivity pattern is the key points of Phased Array Technology. The main contents of the thesis are how to increase the sound field directivity pattern of Phased Array Technology.In the introductory remarks, we discuss the Significance of Phased Array Technology and the research situation. This paper introduces the applications of ultrasonic phased array technology in medicine and ultrasonic testing, and gives the advantages of ultrasonic phased array technology. Then we give the basic ideas and research directions of this paper.The paper then introduces the basic concepts of ultrasonic field and the physical description of the sound field. And introduces phased array technology focusing and deflection theory, and gives the time delay phased array formula, lay a theoretical foundation to the next work.The third part of this paper describes the calculation method for sound field of ultrasound phased array, This article focuses on the directive property of circular array and rectangular array,gives the array transducer order basis, according to this basis, , the system uses ultrasonic probe which used by reversing radar for the common transducer, the system arranged in rectangular phased array: an array of seven probes were composed of the distribution of 2 * 3 rectangular array composed of the six probes, The seventh probe outside the array. The system uses multiple forms of a single collection to the array as a phased array of six probes launched a probe for the seventh received a single probe. Can get some distance in front of the plane m * n the exact focus point. Experimental results show that a small number of the array transducer, focusing accuracy, to meet the requirements of ultrasonic obstacle avoidance.Chapter IV of this paper describes the experimental system's hardware build, given the system the basic processes and methods of spatial scan. The end of the proposed scan chain is 5 * 5 points to the echo signal to a time window of the time interval between successive back to receive the probe in order to receive time base control objectives for each focus point of the launch time. This5 * 5 points the optimal scanning sequence is: the process used to launch and receive the least when the target point first, with more time to sort the post. A target point of focused ultrasound is fired, the following point and this point with some delay with the time difference is equal to the standards of a time window of the delay launching the next point. This approach greatly enhance the scanning speed, applied to the system to save time than that sweeps 90%, to achieve fast, high-precision focusing. This section mainly PFGA timing circuit has been designed so that it can provide a way to sync pulse and 6-channel pulse and 6-channel pulse relative to the sync pulse delay time adjustable.Finally, we summarized this paper and prospected the future work.