柱状线阵列超声换能器指向性研究
发布时间：2019-05-11 18:19
【摘要】：超声技术在工业、农业、军事、健康和其他方面的应用日益广泛,实现电声转换的换能器是技术核心。为了满足各类超声技术应用中具有独特的指向性声场的辐射声源要求,满足不同声场需求的换能器及阵列的研究发展很快。 随着社会发展对超声检测质量要求的不断提高,对超声波的声场也提出了更高的要求。从最简单的传感器阵列到线性阵列、凸阵列、环阵列和相控阵等等类型都获得了快速发展。基于惠更斯原理发展起来的超声相控阵技术,激励信号按一定规则和时序控制激发阵列换能器各个阵元,调整超声扫描波束形状、焦点位置以及声束扫描偏转角。目前绝大部分线阵列的聚焦区域条是线状,扫描面是平面,对于涉及到空间立体的应用,需要比较特殊的圆柱形扫描声场,本文提出满足空间立体声场分布的柱状线阵列超声换能器,进行了以下几方面的研究： (1)理论研究阵列超声换能器的参数、基本组成和诊断仪分辨率的评价标准,讨论设计新型线阵列换能器的理论依据及各种超声阵列的波束处理方法,提出线性阵列换能器新组成方式：以线阵元为基础组成柱状阵列换能器。 (2)通过仿真实验,改变线阵列的参数,间距相同,基元数目参数对新设计换能器栅瓣的影响,研究旁瓣减小的条件。研究表明：当阵元数目增加的时候,主瓣宽度减小；组成线阵的阵元长度和宽度会对阵列的指向性有一定的影响,当阵元长度和宽度越大,线阵列指向性的主瓣宽度越小,栅瓣越大,栅瓣数量越多；当阵元宽度保持不变,阵元长度变大的同时线阵列的指向性越优。 (3)本文提出的柱状阵列换能器的聚焦区域为一个圆环,同时发现阵元的形状对柱状换能器阵列的指向性有一定影响；柱状换能器的聚焦圆环可以通过阵元的激励延时控制改变指向性。
[Abstract]:Ultrasonic technology is widely used in industry, agriculture, military, health and other fields. The transducer to realize electroacoustic conversion is the core of the technology. In order to meet the requirements of radiation sources with unique directional sound field in the application of various ultrasonic technologies, the research of transducer and array to meet the needs of different sound fields has developed rapidly. With the continuous improvement of the quality requirements of ultrasonic testing in the development of society, the sound field of ultrasonic is also put forward higher requirements. From the simplest sensor array to linear array, convex array, ring array and phased array and other types have been developed rapidly. Based on Huygens principle, the ultrasonic phased array technology is developed. The excitation signal controls each array element of the excitation array transducer according to certain rules and timing, and adjusts the beam shape, focus position and beam scanning deflection angle of the ultrasonic scanning. At present, most of the focus area bars of the line array are linear, and the scanning surface is planar. For applications involving spatial stereoscopic, it is necessary to have a special cylindrical scanning sound field. In this paper, a cylindrical linear array ultrasonic transducer satisfying the distribution of spatial stereoscopic sound field is proposed. The following aspects are studied: (1) the parameters, basic composition and evaluation criteria of the resolution of the diagnostic instrument are studied theoretically. This paper discusses the theoretical basis of designing a new type of line array transducer and the beam processing methods of various ultrasonic arrays, and puts forward a new composition method of linear array transducer: cylindrical array transducer based on line array element. (2) through the simulation experiment, the parameters of the line array are changed, the spacing is the same, and the influence of the number of elements on the gate lobe of the newly designed transducer is studied, and the condition of sidelobe reduction is studied. The results show that when the number of elements increases, the width of the main lobe decreases. The length and width of the array elements will have a certain influence on the directivity of the array. when the length and width of the array elements are larger, the smaller the main lobe width of the linear array directivity is, the larger the gate lobe is and the more the number of gate petals is. When the width of the array element remains unchanged, the direction of the line array is better when the length of the array element becomes larger and the direction of the line array is better. (3) the focusing region of the cylindrical array transducer proposed in this paper is a ring, and it is found that the shape of the array element has a certain influence on the directivity of the cylindrical transducer array. The focusing ring of the cylindrical transducer can change the directivity through the excitation delay control of the array element.
【学位授予单位】：陕西师范大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TB552
本文编号：2474737
[Abstract]:Ultrasonic technology is widely used in industry, agriculture, military, health and other fields. The transducer to realize electroacoustic conversion is the core of the technology. In order to meet the requirements of radiation sources with unique directional sound field in the application of various ultrasonic technologies, the research of transducer and array to meet the needs of different sound fields has developed rapidly. With the continuous improvement of the quality requirements of ultrasonic testing in the development of society, the sound field of ultrasonic is also put forward higher requirements. From the simplest sensor array to linear array, convex array, ring array and phased array and other types have been developed rapidly. Based on Huygens principle, the ultrasonic phased array technology is developed. The excitation signal controls each array element of the excitation array transducer according to certain rules and timing, and adjusts the beam shape, focus position and beam scanning deflection angle of the ultrasonic scanning. At present, most of the focus area bars of the line array are linear, and the scanning surface is planar. For applications involving spatial stereoscopic, it is necessary to have a special cylindrical scanning sound field. In this paper, a cylindrical linear array ultrasonic transducer satisfying the distribution of spatial stereoscopic sound field is proposed. The following aspects are studied: (1) the parameters, basic composition and evaluation criteria of the resolution of the diagnostic instrument are studied theoretically. This paper discusses the theoretical basis of designing a new type of line array transducer and the beam processing methods of various ultrasonic arrays, and puts forward a new composition method of linear array transducer: cylindrical array transducer based on line array element. (2) through the simulation experiment, the parameters of the line array are changed, the spacing is the same, and the influence of the number of elements on the gate lobe of the newly designed transducer is studied, and the condition of sidelobe reduction is studied. The results show that when the number of elements increases, the width of the main lobe decreases. The length and width of the array elements will have a certain influence on the directivity of the array. when the length and width of the array elements are larger, the smaller the main lobe width of the linear array directivity is, the larger the gate lobe is and the more the number of gate petals is. When the width of the array element remains unchanged, the direction of the line array is better when the length of the array element becomes larger and the direction of the line array is better. (3) the focusing region of the cylindrical array transducer proposed in this paper is a ring, and it is found that the shape of the array element has a certain influence on the directivity of the cylindrical transducer array. The focusing ring of the cylindrical transducer can change the directivity through the excitation delay control of the array element.
【学位授予单位】：陕西师范大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TB552
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