scholarly journals Optimal Algorithm of Full Focus Array Based on Sparse Matrix

CONVERTER ◽  
2021 ◽  
pp. 770-780
Author(s):  
Donghan Wang, Et al.

Ultrasonic phased array all-focus imaging algorithm has the advantages of high accuracy and full range dynamic focusing, but the existing imaging time-consuming problem limits its practical industrial application. In order to meet the requirements of real-time imaging and clear and distinguishable image defects in all-focus array ultrasound scanning. In this paper, a sparse optimization model of TFM phased array is established. Based on the Fermat principle, the delay time of each element under two layers of media is calculated, and a two-layer media phased array all-focus imaging algorithm is established, using minimal redundancy. The sparse design of the MRLA is carried out, and the all-focus imaging and sparse all-focus imaging experiments of the two-layer medium are carried out, and the influence of the sparse emission array on the defect quantitative accuracy and the calculation efficiency of the all-focus algorithm is discussed. The final optimized sparse array is compared with the sound field beam pattern of the full array, the smallest redundant array, and the genetic algorithm optimized array, and an all-focus scanning environment is established based on the array. Scanning images can not only obtain the maximum amount of information under minimum redundancy, but also have good sidelobe characteristics. At the same time, the array is sparse, which greatly improves the efficiency of all-focus scanning, and provides a certain reference value for the research of all-focus imaging technology.

2015 ◽  
Vol 82 (11) ◽  
Author(s):  
Kevin Mäder ◽  
Richard Nauber ◽  
Hannes Beyer ◽  
Arne Klaß ◽  
Norman Thieme ◽  
...  

AbstractFlow control based on time-dependent magnetic fields is used in various industrial processes involving liquid metals, i. e. during the solidification process of silicon to improve the quality and efficiency of wafers. In order to investigate the interactions between spatiotemporal-varying magnetic fields and conductive fluids numerical simulations are performed. The numerical models are verified by model experiments with opaque low-melting alloys. A suitable measurement technique for flow mapping in such model experiments is ultrasound Doppler velocimetry. In contrast to conventional systems employing transducers with fixed sound field our approach is to use a phased array with the ability to focus and steer its acoustic field. We present the Phased Array Ultrasound Doppler Velocimeter (PAUDV) for flow mapping in magnetohydrodynamics. With its custom host software for control and signal processing experiments that are flexible regarding the experimental setup can be defined.


2011 ◽  
Vol 38 (9) ◽  
pp. 4971-4981 ◽  
Author(s):  
Allison Payne ◽  
Urvi Vyas ◽  
Nick Todd ◽  
Joshua de Bever ◽  
Douglas A. Christensen ◽  
...  

2018 ◽  
Vol 55 (1) ◽  
pp. 011103 ◽  
Author(s):  
卞光宇 Bian Guangyu ◽  
汪毅 Wang Yi ◽  
白宝平 Bai Baoping ◽  
李嘉科 Li Jiake ◽  
陈晓冬 Chen Xiaodong

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