Phased array transmitting system design method based on common small altimeter

Abstract

The invention belongs to the technical field of phased array emission, and particularly relates to a phased array emission system design method based on a common small altimeter. Comprising the following steps of: equidistantly installing a plurality of small altimeters on the same horizontal plane, and gradually transmitting a transducer array formed by the small altimeters from two ends to the center in a 1Ping measurement process in a delayed manner by setting the delay of FPGA logic in the small altimeters and adding a unified external synchronous trigger signal; and sound wave beams emitted by the small altimeter transducers are synthesized and superposed in water, so that the energy of the superposed emitted waves is enhanced and the superposed emitted waves point to a specific curvature center, and the effect of enhancing the directivity of sounding wave beams through phase-controlled emission is achieved. According to the invention, a phase control technology is introduced, and mutual superposition of sound waves in water is enhanced by coupling emission sound wave array planes emitted by a plurality of altimeter transducers, so that the directivity of an emission sound source is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of phased array transmission, and in particular relates to a design method of a phased array transmission system based on a common small altimeter. Background Art

[0002] The directivity of a sound source reflects its sound radiation characteristics in different directions. A highly directional sound source has the characteristics of long propagation distance and small beam angle. It is recognized that it has a significant improvement over traditional sound sources in improving the directivity of echo sounder transmission and increasing the transmission energy of echo sounder.

[0003] Therefore, it is necessary to develop a method based on a combination of multiple ordinary small altimeters (small single-beam depth sounders) to enhance the directivity of the transmitting sound source through synchronous phased transmission. Summary of the invention

[0004] The purpose of the present invention is to overcome the above-mentioned shortcomings of the prior art. The present invention provides a design method for a phased array transmission system based on an ordinary small altimeter. The existing ordinary altimeter products are used to introduce phased control technology. By coupling the transmission sound wave fronts emitted by multiple altimeter transducers, the mutual superposition of sound waves in water is enhanced to improve the directivity of the transmitting sound source. The application of this design can realize the phased array transmission of depth sound waves without the need to redeploy professional equipment and large transducer arrays, and only using a few low-cost small altimeter devices.

[0005] In order to solve the above technical problems, the present invention provides a method for designing a phased array transmitting system based on a common small altimeter, comprising the following steps:

[0006] Multiple small altimeters are installed equidistantly on the same horizontal plane. By setting the delay of the internal FPGA logic of the small altimeter and adding a unified external synchronous trigger signal, the transducer array composed of the small altimeters is gradually delayed from both ends to the center during the 1Ping measurement process, so that the sound wave beams emitted by each small altimeter transducer are synthesized and superimposed in the water, so that the energy of the superimposed transmitted wave is enhanced and pointed to a specific curvature center, so as to achieve the effect of enhancing the directivity of the depth sounding beam by phased transmission.

[0007] Preferably, each of the small altimeters also includes a transmitting unit, which includes: a high-precision clock source, an FPGA chip, a power input module, a DA conversion module, a transmitting drive circuit, a transmitting power amplifier circuit and an ultrasonic transducer; the high-precision clock source, phase delay parameters and synchronization trigger signals are input to the FPGA chip, the power input module supplies power to the FPGA chip, and the FPGA chip is connected to the DA conversion module, the transmitting drive circuit, the transmitting power amplifier circuit and the ultrasonic transducer which are connected in sequence.

[0008] Preferably, according to the actual installation position of each small altimeter, the distance between it and the central small altimeter is measured and calculated, and the phase delay parameter is obtained by calibration and stored in the FPGA chip; wherein the calculation formula for the transmission delay Δt of two adjacent altimeters is:

[0009]

[0010] Wherein, d is the distance between the centers of two small altimeter transducer array elements on the same horizontal plane, θ is the angle between the centers of the two small altimeter transducer array elements relative to the center of curvature, and vl is the propagation speed of sound in water.

[0011] Preferably, the logic in the FPGA chip is programmed to execute a logical delay of the corresponding phase delay time through a transmission delay execution based on the phase delay parameters stored therein and taking the clock signal of the high-precision clock source as a reference when an external synchronous trigger signal arrives, and then generate a logical output transmission drive signal through a transmission drive signal, which is converted by a DA conversion module and sent to a transmission drive circuit. The transmission drive circuit then performs voltage boost modulation on the signal through a transmission power amplifier circuit to drive the ultrasonic transducer to perform a single transmission.

[0012] Preferably, the synchronization trigger signals of the entire phased array transmitting system are connected together and given uniformly by an external device. Under such working conditions, once the external device gives a synchronization trigger signal, all small altimeter devices in the array will be started synchronously and, according to pre-set parameters, emit ultrasonic measurement beams after different delay times, so that the sound waves emitted by the small altimeter array are spatially focused, achieving the effect of enhancing the directivity of the depth measurement beam by phased array transmission.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] The present invention provides a method for enhancing the directivity of an emitted sound source by synchronous phased emission. The existing common altimeter products are used to introduce phased technology, and the emission sound wave fronts emitted by multiple altimeter transducers are coupled to enhance the mutual superposition of sound waves in water, so as to improve the directivity of the emitted sound source. The application of this design can realize the phased array emission of depth sound waves without the need to redeploy professional equipment and large transducer arrays, and only using a few low-cost small altimeter devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The present invention is a flow chart of a method for designing a phased array transmitting system based on a common small altimeter.

[0016] Figure 2 It is a schematic diagram of phased focusing emission of the present invention.

[0017] Figure 3 FIG. 4 is a block diagram of a single altimeter system of the present invention.

[0018] Figure 4 This is the internal logic block diagram of the FPGA chip of the present invention. DETAILED DESCRIPTION

[0019] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The advantages and features of the present invention will become more apparent from the following description. It should be noted that the accompanying drawings are in very simplified form and in non-precise proportions, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

[0020] like Figure 1 As shown, an embodiment of the present invention provides a method for designing a phased array transmission system based on an ordinary small altimeter, including: installing multiple small altimeters at equal distances on the same horizontal height plane, setting the delay of the internal FPGA logic of the small altimeter, and adding a unified external synchronization trigger signal, so that the transducer array composed of the small altimeters is gradually delayed from both ends to the center during the 1 Ping measurement process, and then the sound wave beams emitted by each small altimeter transducer are synthesized and superimposed in the water, so that the energy of the superimposed transmission wave is enhanced and pointed to a specific curvature center, so as to achieve the effect of enhancing the directivity of the depth sounding beam by phased transmission, such as Figure 2 shown.

[0021] The transmitting part of each small altimeter includes a high-precision clock source, an FPGA chip, a power input module, a DA conversion module, a transmitting drive circuit, a transmitting power amplifier circuit, and an ultrasonic transducer. The overall block diagram is as follows Figure 3 shown.

[0022] According to the actual installation position of each small altimeter, the distance between it and the central device is measured and calculated, and the phase delay parameters are obtained through calibration and stored in the device. Among them, the calculation formula for the transmission delay Δt of two adjacent altimeters is:

[0023]

[0024] In the above formula, d is the distance between the centers of two small altimeter transducer array elements on the same horizontal plane, θ is the angle between the centers of the two small altimeter transducer array elements relative to the center of curvature, and vl is the propagation speed of sound in water.

[0025] The delayed emission control of each individual small altimeter is performed by the FPGA chip in it. FPGA (Field Programmable Gate Array) is a chip whose internal structure can be programmed to achieve the purpose of use. It is mainly composed of programmable logic units, input and output units and programmable interconnection resources, and works based on lookup table technology. Using FPGA with a high-precision clock source can achieve accurate and reliable clock delay at the nanosecond (ns) level, ensuring the phase accuracy of the emission phase-controlled delay.

[0026] The logic in the small altimeter FPGA chip is programmed to execute the logic delay of the corresponding phase delay time through the transmission delay execution according to the phase delay parameters stored when the external synchronous trigger signal arrives, taking the clock signal of the high-precision clock source as the reference, and then generate the logic output through the transmission drive signal. The transmission drive signal is given to the transmission drive circuit after DA conversion, and the transmission drive circuit then boosts and modulates the signal through the transmission power amplifier circuit to drive the ultrasonic transducer to perform a single transmission. Its logic block diagram is as follows Figure 4 shown.

[0027] The synchronization trigger signals of the entire system are connected together and given uniformly by external equipment. Under such working conditions, once the external equipment gives a synchronization trigger signal, all altimeter devices in the array will start synchronously and, according to the pre-set parameters, emit ultrasonic measurement beams after different delay times, so that the sound waves emitted by the altimeter array are spatially focused, achieving the effect of phased emission to enhance the directivity of the depth measurement beam.

[0028] In summary, an array of multiple small altimeters is installed on the test platform ship, and the sound intensity of the array during phased transmission is detected by placing a standard hydrophone at the center of curvature. Compared with the same array without phased transmission, the sound intensity is significantly improved.

[0029] The above description is only a description of the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention. Any changes or modifications made by a person skilled in the art in the field of the present invention based on the above disclosure shall fall within the scope of protection of the claims.

Claims

1. A design method for a phased array transmitting system based on a common small altimeter, characterized in that: The steps include: Multiple small altimeters are installed equidistantly on the same horizontal plane. By setting the delay of the internal FPGA logic of the small altimeter and adding a unified external synchronous trigger signal, the transducer array composed of the small altimeters is gradually delayed from both ends to the center during the 1Ping measurement process, so that the sound wave beams emitted by each small altimeter transducer are synthesized and superimposed in the water, so that the energy of the superimposed transmitted wave is enhanced and pointed to a specific curvature center, so as to achieve the effect of enhancing the directivity of the depth sounding beam by phased transmission.

2. The method for designing a phased array transmitting system based on a common small altimeter according to claim 1, characterized in that: Each of the small altimeters also includes a transmitting part, which includes: a high-precision clock source, an FPGA chip, a power input module, a DA conversion module, a transmitting drive circuit, a transmitting power amplifier circuit and an ultrasonic transducer; the high-precision clock source, phase delay parameters and synchronization trigger signals are input into the FPGA chip, the power input module supplies power to the FPGA chip, and the FPGA chip is connected to the DA conversion module, the transmitting drive circuit, the transmitting power amplifier circuit and the ultrasonic transducer which are connected in sequence.

3. The method for designing a phased array transmitting system based on a common small altimeter as claimed in claim 2, characterized in that: According to the actual installation position of each small altimeter, the distance between it and the central small altimeter is measured and calculated, and the phase delay parameter is obtained by calibration and stored in the FPGA chip; wherein, the calculation formula of the transmission delay Δt of two adjacent altimeters is: Wherein, d is the distance between the centers of two small altimeter transducer array elements on the same horizontal plane, θ is the angle between the centers of the two small altimeter transducer array elements relative to the center of curvature, and vl is the propagation speed of sound in water.

4. The method for designing a phased array transmitting system based on a common small altimeter as claimed in claim 2, characterized in that: The logic in the FPGA chip is programmed to, when an external synchronous trigger signal arrives, based on the phase delay parameters it has stored and taking the clock signal of the high-precision clock source as a reference, execute a logical delay of the corresponding phase delay time through the transmission delay execution, and then generate a logical output transmission drive signal through the transmission drive signal, which is sent to the transmission drive circuit after conversion by the DA conversion module. The transmission drive circuit then boosts and modulates the signal through the transmission power amplifier circuit to drive the ultrasonic transducer to perform a single transmission.

5. A method for designing a phased array transmitting system based on a common small altimeter as claimed in any one of claims 1 to 4, characterized in that: The synchronization trigger signals of the entire phased array transmitting system are connected together and given uniformly by an external device. Under such working conditions, once the external device gives a synchronization trigger signal, all small altimeter devices in the array will start synchronously and emit ultrasonic measurement beams after different delays according to pre-set parameters, so that the sound waves emitted by the small altimeter array are spatially focused, achieving the effect of phased transmission to enhance the directivity of the depth sounding beam.

Images