相控阵超声信号动态变迹技术研究及实现
发布时间：2018-08-21 13:41
【摘要】：众多超声相控阵技术中,波束合成和空间扫描都是基于对阵元的时延或相位控制,要解决的根本问题是在声束形成时产生具有尽可能低的旁瓣波形,并进行空间电子扫描,而作为阵元信号的另一个可控变量,辐射幅度一直没有得到应有的考虑。因此,针对相控阵超声信号处理,我们提出了一种动态变迹的方法,希望通过对各个阵元信号幅度加上窗函数的权值来获得主瓣更窄、旁瓣更少、旁瓣数量级更低的声束分布,以此改善波束的指向性。 再有,传统的相控阵超声检测系统由上位机生成波束合成所需的各种参数,系统体积庞大且集成度不高,而采用FPGA实现可很好地避免这一问题,需考虑的是数字控制引起的误差及精度要求。不仅如此,研究发现,通过对阵元幅度进行加权,可以实现人们所需要的远场波形及近场声束聚焦。因此,采用幅度加权的方法形成波束,采用线性相位控制进行空间扫描,还可很大程度降低检测系统的复杂度和节约成本。 本文理论设计通过Matlab模拟方法的可行性,再在Field Ⅱ超声仿真平台上进行相关算法的声束控制实验,并验证理论研究；数字实现部分先通过Modelsim的波形仿真时序验证方案的正确性,进而在已有的相控阵超声检测实验平台测试其功能的完备性及精确度。复杂算法模块的信号处理及各模块的控制借助FPGA和DSP技术完成,而强大的设计开发工具Quartus Ⅱ、CCS及丰富的EDA电子应用使总体方案得以实现。 以上数字主控平台设计主要基于Altera公司的Cyclone系列芯片,该芯片引脚丰富,逻辑门充足,且内嵌DSP核,有利于各种算法处理的实现。
[Abstract]:In many ultrasonic phased array technologies, beam synthesis and space scanning are based on the time delay or phase control of the opposing elements. The fundamental problem to be solved is to generate as low a sidelobe waveform as possible when the sound beam is formed, and to conduct spatial electronic scanning. As another controllable variable of array element signal, the radiation amplitude has not been given due consideration. Therefore, for the ultrasonic signal processing of phased array, we propose a dynamic method to change the number of nodes. We hope to obtain a narrower main lobe, less sidelobe and lower magnitude of sidelobe by adding the weight of window function to the signal amplitude of each array element. In order to improve the directivity of the beam. Furthermore, the traditional phased array ultrasonic detection system needs all kinds of parameters needed by PC to generate beam synthesis. The system is large in volume and low in integration, but this problem can be avoided by using FPGA. It is necessary to consider the error and precision requirement caused by digital control. Moreover, it is found that the far-field waveform and near-field acoustic beam focus can be realized by weighting the amplitude of the face element. Therefore, using amplitude weighting method to form beam and linear phase control for spatial scanning can greatly reduce the complexity and cost of the detection system. In this paper, the feasibility of the Matlab simulation method is designed, then the acoustic beam control experiment of the related algorithm is carried out on the Field 鈪，
本文编号：2195912
[Abstract]:In many ultrasonic phased array technologies, beam synthesis and space scanning are based on the time delay or phase control of the opposing elements. The fundamental problem to be solved is to generate as low a sidelobe waveform as possible when the sound beam is formed, and to conduct spatial electronic scanning. As another controllable variable of array element signal, the radiation amplitude has not been given due consideration. Therefore, for the ultrasonic signal processing of phased array, we propose a dynamic method to change the number of nodes. We hope to obtain a narrower main lobe, less sidelobe and lower magnitude of sidelobe by adding the weight of window function to the signal amplitude of each array element. In order to improve the directivity of the beam. Furthermore, the traditional phased array ultrasonic detection system needs all kinds of parameters needed by PC to generate beam synthesis. The system is large in volume and low in integration, but this problem can be avoided by using FPGA. It is necessary to consider the error and precision requirement caused by digital control. Moreover, it is found that the far-field waveform and near-field acoustic beam focus can be realized by weighting the amplitude of the face element. Therefore, using amplitude weighting method to form beam and linear phase control for spatial scanning can greatly reduce the complexity and cost of the detection system. In this paper, the feasibility of the Matlab simulation method is designed, then the acoustic beam control experiment of the related algorithm is carried out on the Field 鈪，
本文编号：2195912
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