A method for arranging low-frequency and high-power volume arrays with broadband transmission

Abstract

The present invention discloses a method for arranging a low-frequency, high-power volume array for broadband transmission, wherein the volume array is composed of eight transducers, and the steps are as follows: 1. Arrange four layers of binary sub-arrays along the height direction of the transducers as a group of two transducers, and the four layers of binary sub-arrays form an eight-element volume array; the four layers of binary sub-arrays have the same orientation, and are arranged alternately between layers. The center spacing between two transducers in each layer of binary sub-arrays is αλ, and the vertical spacing and horizontal spacing between the centers of the transducers between layers are both αλ; 2. Rotate the four transducers of the binary sub-arrays of the top and bottom layers, or the four diagonally distributed transducers in any two adjacent layers of binary sub-arrays, by 90 degrees along their respective center lines parallel to the long axis direction to form the final eight-element volume array. The beneficial effects of the present invention are as follows: the present invention forms two new types of volume arrays by introducing two different transducer orientations in the volume array, which can effectively broaden the working bandwidth of the base array and can be used for low-frequency active sonar.

Description

Technical Field

[0001] The invention belongs to the field of underwater acoustic transducer arrays, and mainly relates to a low-frequency and high-power volume array arrangement method for broadband transmission. Background Art

[0002] The development trend of active sonar is low frequency, small size, high power and broadband. Among them, the advantages of broadband performance are: strong environmental adaptability. In the complex environment of shallow sea, the reverberation formed by multipath effect has a great influence on the sonar performance. Broadband signal can improve the detection ability of sonar under the background of reverberation; high accuracy in estimating target motion parameters, because the distance resolution is proportional to the signal bandwidth, so the wider the bandwidth, the higher the distance resolution accuracy. At the same time, broadband signal can make the target echo carry more target information, making the sonar target recognition ability stronger.

[0003] In order to achieve the overall sonar indicators, transducers generally need to be used in an array to increase the sound source level and achieve directional emission. Traditional array methods mostly use 1 / 2 wavelength arrays on planes or cylindrical surfaces, and achieve low sidelobe directional emission through delay compensation and amplitude control. The array elements of the base array are generally longitudinal vibration transducers or curved disk transducers. The disadvantage of this array method is that the number of array elements in the base array is severely limited by the array space. Volume arrays do not require transducers to be on the same plane, so volume array technology can make better use of the array space, maintain the number of base array elements within an appropriate range, and ensure that the sonar radiated sound power is not reduced. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and to provide a method for arranging a low-frequency, high-power volume array with broadband transmission, which can be used to improve the working bandwidth of a transducer array.

[0005] The object of the present invention is achieved by the following technical solution: A method for arranging a low-frequency, high-power volume array for broadband transmission, wherein the volume array is composed of eight transducers and comprises the following steps:

[0006] (1) Arrange two transducers in a group into four layers of binary sub-arrays along the height direction of the transducers, and the four layers of binary sub-arrays form an eight-element volume array; the four layers of binary sub-arrays have the same orientation and are arranged alternately between layers. The center spacing between two transducers in each layer of binary sub-array is αλ, where λ is the wavelength and α is the wavelength coefficient. The vertical spacing and horizontal spacing between the centers of the transducers between layers are both αλ;

[0007] (2) The four transducers of the top and bottom layers of the binary sub-array, or the four diagonally distributed transducers of any two adjacent layers of the binary sub-array, are rotated 90 degrees along their respective center lines parallel to the long axis direction to form a final eight-element volume array.

[0008] As a preferred technical solution, every two transducers are grouped into a four-layer binary sub-array along the height direction of the transducer at a quarter wavelength of a given frequency. The four-layer binary sub-array forms an eight-element volume array with coordinates (0, 0), (λ / 4, -λ / 4), (λ / 2, 0) and (3λ / 4, -λ / 4) in a plane perpendicular to the height direction of the transducer.

[0009] As a preferred technical solution, the transducer may be other types of flextensional transducers, slotted annular transducers, and other transducers capable of forming a volume array, including but not limited to the type IV flextensional transducer described in the example.

[0010] The beneficial effects of the present invention are as follows: the present invention proposes a new volume array arrangement method, by introducing two different transducer orientations in the volume array, two new volume array formations are formed, and by optimizing and adjusting the base array formation and array spacing, the interaction between the volume array elements can be improved, the base array working bandwidth can be effectively broadened, and it can be used for low-frequency active sonar. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is the original basic formation diagram before rotation.

[0012] Figure 2 This is the 1# array diagram of the eight-element piezoelectric array of the present invention.

[0013] Figure 3 for Figure 3 Front view of .

[0014] Figure 4 for Figure 2 Right view of .

[0015] Figure 5 This is the 2# array diagram of the eight-element piezoelectric array of the present invention.

[0016] Figure 6 for Figure 5 Front view of .

[0017] Figure 7 for Figure 6 Right view of .

[0018] Figure 8 The transmission voltage response curve of the octal piezoelectric array 1# of the present invention.

[0019] Fig. 9 The transmission voltage response curve of the 2# array of the eight-element piezoelectric array of the present invention.

[0020] Explanation of the reference numerals: first transducer a1-1, second transducer a1-2, first transducer b2-1, second transducer b2-2, first transducer c3-1, second transducer c3-2, first transducer d4-1, second transducer d4-2. DETAILED DESCRIPTION

[0021] The present invention will be described in detail below with reference to the accompanying drawings and embodiments:

[0022] The volume array of underwater acoustic transducers described in the present invention is composed of 8 type IV flextensional transducers, and the 8 type IV flextensional transducers are arranged in an open space according to a certain pattern to form a volume array. The biggest difference between a volume array and a traditional planar array is that there are scattered sound waves between the array elements in the volume array, while there is no scattering between the array elements of a planar array. The scattering between the array elements of a volume array has a great influence on the radiation impedance of each array element, so the arrangement of the array elements of a volume array has a decisive influence on the overall working performance of the array. The volume array array type described in the present invention can significantly increase the working bandwidth of the array.

[0023] The maximum response, resonance peak and working bandwidth of the array may vary greatly with different array element spacing. The maximum value of the array element spacing is determined according to the array space, and the minimum value of the array element spacing is determined according to the array element size. At the same time, the required working frequency band is considered to select the optimal array element spacing. The array element spacing described in this example is a quarter wavelength of a given frequency.

[0024] like Figure 1 As shown, every two type IV flextensional transducers in the base array form a group and are divided into four groups a, b, c, and d. The two type IV flextensional transducers in each group are arranged into a binary sub-array at a quarter wavelength interval in the transducer height direction. Group a includes the first transducer a1-1 and the second transducer a1-2, group b includes the first transducer b2-1 and the second transducer b2-2, group c includes the first transducer c3-1 and the second transducer c3-2, and group d includes the first transducer d4-1 and the second transducer d4-2. The directions of the four groups of binary sub-arrays a, b, c, and d are all in the same direction as the y-axis, and the center points A, B, C, and D of the four binary sub-arrays are on the xz plane, so the spatial distribution of the four binary sub-arrays can be determined by their center points. Taking point A as the origin, the coordinates of points A, B, C, and D on the xz plane are (0, 0), (λ / 4, -λ / 4), (λ / 2, 0), and (3λ / 4, -λ / 4), respectively.

[0025] The eight-element piezoelectric array 1# array is shown in the figure Figure 2-4As shown, the four transducers in the two groups of binary sub-arrays a and d (the first transducer a1-1, the second transducer a1-2, the first transducer d4-1, and the second transducer d4-2) are rotated 90 degrees along the center line of their respective long axes as the rotation axis, and the other transducers remain as they are, ultimately forming an eight-element piezoelectric array 1# formation. Figure 8 The simulation results of the 1# array are shown in the right two figures. The directivity at different frequencies in the yz plane of the array horizontal plane is shown in the figure below. The 0° direction is the z direction, and the 270° direction is the y direction. The left figure shows the transmission voltage response results in the direction of the maximum directivity. The maximum transmission voltage response of the array shown is reduced by 3dB, and the working bandwidth is widened by 63%.

[0026] The 2# array of the eight-element piezoelectric array is shown in the figure Figure 5-7 As shown, the second transducer a1-2, the first transducer b2-1, the second transducer c3-2, and the first transducer d4-1 are respectively rotated 90 degrees along the center line of their respective long axis directions as the rotation axis, and the other transducers remain as they are, ultimately forming an eight-element piezoelectric array 2# formation. Fig. 9 The simulation results of the 2# array are shown in the right two figures. The directivity at different frequencies in the yz plane of the array horizontal plane is shown in the figure below. The 0° direction is the z direction, and the 270° direction is the y direction. The left figure shows the transmission voltage response results in the direction of the maximum directivity. The maximum transmission voltage response of the array shown is reduced by 2dB, and the working bandwidth is widened by 59%.

[0027] According to the different rotating transducers, two different formations are formed. The simulation results of the transmission voltage response of the formation are as follows: Figure 8 and Fig. 9 The maximum voltage response of the middle formation has decreased, but Figure 8 and Fig. 9 The bandwidth of the formation has been increased.

[0028] It is understandable that, for those skilled in the art, any equivalent replacement or change to the technical solution and inventive concept of the present invention should fall within the protection scope of the claims attached to the present invention.

Claims

1. A method for arranging a low-frequency, high-power volume array for broadband transmission, characterized in that: The volume array is composed of eight transducers and includes the following steps: (1) Arrange two transducers in a group into four layers of binary sub-arrays along the height direction of the transducers, and the four layers of binary sub-arrays form an eight-element volume array; the four layers of binary sub-arrays have the same orientation and are arranged alternately between layers. The center spacing between two transducers in each layer of binary sub-array is αλ, where λ is the wavelength and α is the wavelength coefficient. The vertical spacing and horizontal spacing between the centers of the transducers between layers are both αλ; (2) The four transducers of the top and bottom layers of the binary sub-array, or the four diagonally distributed transducers of any two adjacent layers of the binary sub-array, are rotated 90 degrees along their respective center lines parallel to the long axis direction to form a final eight-element volume array.

2. The method for arranging a low-frequency, high-power volume array for broadband transmission according to claim 1, characterized in that: Every two transducers are grouped into a four-layer binary sub-array along the height direction of the transducer at a quarter wavelength of a given frequency. The four-layer binary sub-array forms an eight-element volume array with coordinates (0, 0), (λ / 4, -λ / 4), (λ / 2, 0) and (3λ / 4, -λ / 4) in the plane perpendicular to the height direction of the transducer.

3. The method for arranging a low-frequency, high-power volume array for broadband transmission according to claim 1 or 2, characterized in that: The transducer is a type IV flextensional transducer, or other transducers capable of forming a volume array.

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