相控陣超聲信號動態(tài)變跡技術研究及實現
發(fā)布時間：2018-08-21 13:41
【摘要】：眾多超聲相控陣技術中,波束合成和空間掃描都是基于對陣元的時延或相位控制,要解決的根本問題是在聲束形成時產生具有盡可能低的旁瓣波形,并進行空間電子掃描,而作為陣元信號的另一個可控變量,輻射幅度一直沒有得到應有的考慮。因此,針對相控陣超聲信號處理,我們提出了一種動態(tài)變跡的方法,希望通過對各個陣元信號幅度加上窗函數的權值來獲得主瓣更窄、旁瓣更少、旁瓣數量級更低的聲束分布,以此改善波束的指向性。 再有,傳統(tǒng)的相控陣超聲檢測系統(tǒng)由上位機生成波束合成所需的各種參數,系統(tǒng)體積龐大且集成度不高,而采用FPGA實現可很好地避免這一問題,需考慮的是數字控制引起的誤差及精度要求。不僅如此,研究發(fā)現,通過對陣元幅度進行加權,可以實現人們所需要的遠場波形及近場聲束聚焦。因此,采用幅度加權的方法形成波束,采用線性相位控制進行空間掃描,還可很大程度降低檢測系統(tǒng)的復雜度和節(jié)約成本。 本文理論設計通過Matlab模擬方法的可行性,再在Field Ⅱ超聲仿真平臺上進行相關算法的聲束控制實驗,并驗證理論研究；數字實現部分先通過Modelsim的波形仿真時序驗證方案的正確性,進而在已有的相控陣超聲檢測實驗平臺測試其功能的完備性及精確度。復雜算法模塊的信號處理及各模塊的控制借助FPGA和DSP技術完成,而強大的設計開發(fā)工具Quartus Ⅱ、CCS及豐富的EDA電子應用使總體方案得以實現。 以上數字主控平臺設計主要基于Altera公司的Cyclone系列芯片,該芯片引腳豐富,邏輯門充足,且內嵌DSP核,有利于各種算法處理的實現。
[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，
本文編號：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，
本文編號：2195912
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