Distance detection method and device for underwater target, electronic equipment and program product

Abstract

The invention is suitable for the technical field of distance measurement, and provides a distance detection method and device for an underwater target, electronic equipment and a program product. The method is applied to a frequency-modulated continuous wave laser detection system, and a signal receiving end of the frequency-modulated continuous wave laser detection system comprises a two-dimensional matrix detector array composed of a plurality of single-photon avalanche photodiodes. The method comprises the following steps: transmitting a plurality of first laser signals with different frequencies to an underwater target through a signal transmitting end of a frequency-modulated continuous wave laser detection system; receiving second laser signals with different frequencies through a plurality of single-photon avalanche photodiodes; performing two-dimensional discrete synthesis processing on the second laser signals with different frequencies to obtain target echo signals; and determining the distance between the underwater target and the frequency-modulated continuous wave laser detection system according to the target echo signal. According to the frequency-modulated continuous wave laser detection system, a plurality of laser signals with different frequencies can be transmitted and received, so that the detection distance and the resolution ratio of an underwater target can be improved.

Description

Technical Field

[0001] The present application belongs to the field of distance measurement technology, and in particular, relates to a distance detection method, device, electronic equipment and program product for underwater targets. Background Art

[0002] At present, underwater target detection technologies mainly include hydroacoustic detection technology and laser detection technology. Compared with hydroacoustic detection technology, laser detection technology has the advantages of low latency and strong anti-interference. The commonly used laser detection system is the Time of Flight (TOF) underwater laser detection system. However, due to the serious attenuation of light waves during underwater transmission, the scattering and absorption of light by low-reflectivity objects will also limit the underwater detection distance to a certain extent. Therefore, the detection distance of the TOF underwater laser detection system is relatively short. In addition, since the TOF underwater laser detection system can usually only transmit and receive laser signals with a narrow bandwidth, the resolution of the TOF underwater laser detection system is relatively low, resulting in a short detection distance and low resolution for detecting underwater targets. Summary of the invention

[0003] In view of this, the embodiments of the present application provide a method, device, electronic device and program product for detecting the distance of an underwater target to solve the technical problems of short detection distance and low resolution in the existing detection of underwater targets.

[0004] In a first aspect, an embodiment of the present application provides a method for detecting the distance of an underwater target, which is applied to a frequency modulated continuous wave laser detection system, wherein a signal receiving end of the frequency modulated continuous wave laser detection system includes a two-dimensional matrix detector array composed of multiple single photon avalanche photodiodes, and the method includes: Transmitting a plurality of first laser signals of different frequencies to the underwater target through a signal transmitting end of the frequency modulated continuous wave laser detection system; receiving second laser signals of different frequencies through the multiple single-photon avalanche photodiodes; the second laser signal is a signal reflected by the multiple single-photon avalanche photodiodes after the first laser signal is emitted to the underwater target, and the frequencies of the second laser signals received by the respective single-photon avalanche photodiodes are not completely the same; Performing two-dimensional discrete synthesis processing on the second laser signals of different frequencies to obtain target echo signals; The distance between the underwater target and the frequency modulated continuous wave laser detection system is determined according to the target echo signal.

[0005] Optionally, the signal transmitting end includes a signal generator, a signal driver, a distributed feedback laser, a signal beam splitter and a signal circulator, and the signal transmitting end of the frequency modulated continuous wave laser detection system transmits a plurality of first laser signals of different frequencies to the underwater target, including: Outputting a modulation signal to the signal driver through the signal generator; Outputting a modulation current to the distributed feedback laser according to the modulation signal through the signal driver; generating a linear chirped optical signal according to the modulation current through the distributed feedback laser, and outputting the linear chirped optical signal to the signal beam splitter; generating the first laser signal according to the linear chirped optical signal through the signal beam splitter, and outputting the first laser signal to the signal circulator; The first laser signal is transmitted to the underwater target through the signal circulator.

[0006] Optionally, generating a linear chirp optical signal by the distributed feedback laser according to the modulation current includes: Obtaining the current detection distance and current distance resolution of the frequency modulated continuous wave laser detection system; If the current detection distance is less than a preset detection distance threshold, and the current distance resolution is greater than a preset distance resolution threshold, the linear chirp optical signal is generated by the distributed feedback laser according to the modulation current in a step frequency modulation manner; If the current detection distance is greater than or equal to the detection distance threshold, and the current distance resolution is less than or equal to the distance resolution threshold, the linear chirp light signal is generated by the distributed feedback laser in a linear frequency modulation manner according to the modulation current.

[0007] Optionally, the signal receiving end further includes the signal circulator, and the receiving of the second laser signals of different frequencies through the multiple single-photon avalanche photodiodes includes: receiving the second laser signals of different frequencies through the signal circulator, and outputting the second laser signals of different frequencies to the two-dimensional matrix detector array; The second laser signal of one frequency is received by each of the single-photon avalanche photodiodes.

[0008] Optionally, the two-dimensional matrix detector array includes a first detector array in a first direction and a second detector array in a second direction, and the number of the single-photon avalanche photodiodes included in the first detector array is the same as the number of the single-photon avalanche photodiodes included in the second detector array.

[0009] Optionally, before receiving the second laser signals with different frequencies through the multiple single-photon avalanche photodiodes, the method further includes: Obtaining a minimum value of a light intensity requirement range of the frequency modulated continuous wave laser detection system and a preset incident angle of the second laser signal; Determining a first spacing between each of the first detector arrays and a second spacing between each of the second detector arrays according to a minimum value of the light intensity requirement range and the preset incident angle; The pitch of the two-dimensional matrix detector array is adjusted according to the first pitch and the second pitch.

[0010] Optionally, the signal receiving end further includes a phase shifter and a beam combiner; the two-dimensional discrete synthesis processing of the second laser signals of different frequencies to obtain the target echo signal includes: Performing phase distortion compensation processing on each of the second laser signals by using the phase shifter; The beam combiner performs optical wave combining processing on each of the second laser signals after the phase distortion compensation processing to obtain the target echo signal.

[0011] In a second aspect, an embodiment of the present application provides a distance detection device for an underwater target, which is applied to a frequency modulated continuous wave laser detection system, wherein a signal receiving end of the frequency modulated continuous wave laser detection system includes a two-dimensional matrix detector array composed of multiple single photon avalanche photodiodes, and the device includes: A signal transmitting unit, used for transmitting a plurality of first laser signals of different frequencies to an underwater target through a signal transmitting end of the frequency modulated continuous wave laser detection system; A signal receiving unit, configured to receive second laser signals of different frequencies through the multiple single-photon avalanche photodiodes; the second laser signal is a signal generated by the first laser signal being emitted to the underwater target and then reflected to the multiple single-photon avalanche photodiodes, and the frequencies of the second laser signals received by the respective single-photon avalanche photodiodes are not completely the same; A signal processing unit, used for performing two-dimensional discrete synthesis processing on the second laser signals of different frequencies to obtain a target echo signal; The distance determination unit is used to determine the distance between the underwater target and the frequency modulated continuous wave laser detection system according to the target echo signal.

[0012] In a third aspect, an embodiment of the present application provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, each step of the underwater target distance detection method as described in the first aspect is implemented.

[0013] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the underwater target distance detection method as described in the first aspect above.

[0014] In a fifth aspect, an embodiment of the present application provides a computer program. When the computer program is run on an electronic device, the electronic device executes each step of the underwater target distance detection method as described in the first aspect above.

[0015] The underwater target distance detection method, device, electronic device and program product provided by the embodiments of the present application have the following beneficial effects: The distance detection method for underwater targets provided in the embodiment of the present application can be applied to a frequency modulated continuous wave laser detection system, wherein the signal receiving end of the frequency modulated continuous wave laser detection system includes a two-dimensional matrix detector array composed of multiple single-photon avalanche photodiodes, and the method includes: transmitting multiple first laser signals of different frequencies to the underwater target through the signal transmitting end of the frequency modulated continuous wave laser detection system; receiving second laser signals of different frequencies through multiple single-photon avalanche photodiodes, wherein the second laser signal is a signal reflected to multiple single-photon avalanche photodiodes after the first laser signal is emitted to the underwater target, and the frequencies of the second laser signals received by each single-photon avalanche photodiode are not completely the same; performing two-dimensional discrete synthesis processing on the second laser signals of different frequencies to obtain a target echo signal; according to the target echo signal, determining the distance between the underwater target and the frequency modulated continuous wave laser detection system. The frequency modulated continuous wave laser detection system of the present application can transmit and receive multiple laser signals of different frequencies through a two-dimensional matrix detector array composed of multiple single-photon avalanche photodiodes, so the area for receiving laser signals is large, which can improve the detection distance of underwater targets, and the frequency of the received laser signals is large, so the resolution of detecting underwater targets can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0017] Figure 1 A flowchart of a method for detecting the distance of an underwater target provided in an embodiment of the present application; Figure 2 A schematic diagram of the structure of a two-dimensional matrix detector array provided in an embodiment of the present application; Figure 3 A schematic diagram of a preset incident angle of a laser signal provided in an embodiment of the present application; Figure 4 A schematic diagram of the structure of a distance detection device for an underwater target provided in an embodiment of the present application; Figure 5 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0018] It should be noted that the terms used in the embodiments of the present application are only used to explain the specific embodiments of the present application, and are not intended to limit the present application. In the description of the embodiments of the present application, unless otherwise specified, "multiple" refers to two or more than two, and "at least one", "one or more" refers to one, two or more. The terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, it is defined that the "first" and "second" features can explicitly or implicitly include one or more of the features.

[0019] References to "one embodiment" or "some embodiments" etc. described in this specification mean that a particular feature, structure or characteristic described in conjunction with the embodiment is included in one or more embodiments of the present application. Thus, the phrases "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear at different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0020] The execution subject of the underwater target distance detection method provided in the embodiment of the present application can be a frequency modulated continuous wave laser detection system, wherein the signal receiving end of the frequency modulated continuous wave laser detection system includes a two-dimensional matrix detector array composed of multiple single-photon avalanche photodiodes. When it is necessary to improve the detection distance and resolution of underwater targets, the frequency modulated continuous wave laser detection system provided in the embodiment of the present application can be used to perform the various steps of the underwater target distance detection method provided in the embodiment of the present application, thereby improving the detection distance and resolution of underwater targets.

[0021] See also Figure 1 , Figure 1A flow chart for implementing a method for detecting the distance of an underwater target provided in an embodiment of the present application. The method for detecting the distance of an underwater target provided in an embodiment of the present application can be applied to a frequency modulated continuous wave laser detection system, and the signal receiving end of the frequency modulated continuous wave laser detection system includes a two-dimensional matrix detector array composed of multiple single-photon avalanche photodiodes.

[0022] See also Figure 2 , Figure 2 This is a schematic diagram of the structure of a two-dimensional matrix detector array provided in an embodiment of the present application. Figure 2 As shown, the two-dimensional matrix detector array may include a first detector array in a first direction and a second detector array in a second direction, wherein the number of single-photon avalanche photodiodes included in the first detector array is the same as the number of single-photon avalanche photodiodes included in the second detector array. Figure 2 As shown, exemplarily, the number of single-photon avalanche photodiodes included in the first detector array and the number of single-photon avalanche photodiodes included in the second detector array can both be 8, that is, the two-dimensional matrix detector array can include 8×8 single-photon avalanche photodiodes.

[0023] In the two-dimensional matrix detector array provided in the embodiment of the present application, each single-photon avalanche photodiode can receive a laser signal of a preset frequency, and the frequency of the laser signal received by each single-photon avalanche photodiode in the two-dimensional matrix detector array is not exactly the same, thereby improving the resolution of detecting underwater targets.

[0024] In practical applications, even if only a single photon is incident on a single-photon avalanche photodiode, the single-photon avalanche photodiode will generate a large current due to the avalanche effect. Therefore, the two-dimensional matrix detector array composed of multiple single-photon avalanche photodiodes has the ability to detect single photons. Therefore, when detecting the distance of underwater targets, the two-dimensional matrix detector composed of multiple single-photon avalanche photodiodes can also improve the detection distance of underwater targets.

[0025] Based on the two-dimensional matrix detector array provided above, such as Figure 1 As shown, a method for detecting the distance of an underwater target provided in an embodiment of the present application may include steps S101 to S104, which are described in detail as follows: In S101, a plurality of first laser signals with different frequencies are transmitted to an underwater target through a signal transmitting end of a frequency modulated continuous wave laser detection system.

[0026] In an embodiment of the present application, when it is necessary to detect the distance of an underwater target, a plurality of first laser signals of different frequencies can be emitted to the underwater target through a signal transmitting end of a frequency modulated continuous wave laser detection system.

[0027] The specific frequency of each first laser signal can be set according to actual needs.

[0028] In a possible implementation, the signal transmitting end of the frequency modulated continuous wave laser detection system may include a signal generator, a signal driver, a distributed feedback laser, a signal beam splitter, and a signal circulator. Based on this, steps a to e may be performed to transmit a plurality of first laser signals of different frequencies to an underwater target through the signal transmitting end of the frequency modulated continuous wave laser detection system. The details are as follows: In step a, a modulation signal is output to a signal driver through a signal generator.

[0029] In this implementation, when it is necessary to transmit a plurality of first laser signals of different frequencies to an underwater target through a signal transmitting end of a frequency modulated continuous wave laser detection system, a modulation signal can be first output to a signal driver through a signal generator. The modulation signal can be used to generate a modulation current. Exemplarily, the modulation signal can be a triangular wave signal.

[0030] In step b, a modulation current is output to the distributed feedback laser through a signal driver according to a modulation signal.

[0031] In this implementation, after receiving the modulation signal, the signal driver can synthesize, amplify or scale the modulation signal with the required DC bias current so that the modulation current entering the laser has the correct bias and modulation amplitude.

[0032] In step c, a linear chirp optical signal is generated according to a modulation current by a distributed feedback laser, and the linear chirp optical signal is output to a signal beam splitter.

[0033] In this implementation, the laser diode in the distributed feedback laser outputs a single-frequency laser signal. Under the modulation of the modulation current, the frequency of the laser signal will periodically sweep within a bandwidth range (such as from low frequency to high frequency and then back to low frequency), forming a linear chirped light signal.

[0034] In practical applications, the output wavelength of a distributed feedback laser is very sensitive to temperature. In order to ensure the accuracy and repeatability of frequency modulation (chirp) in a frequency modulated continuous wave laser detection system, the temperature of the distributed feedback laser needs to be maintained within a specific and stable range. This can reduce the wavelength drift caused by ambient temperature fluctuations and ensure that the linear frequency modulation characteristics of the linear chirp optical signal remain good.

[0035] In a possible implementation, the distributed feedback laser can select different methods to generate a linear chirped light signal according to actual conditions. Specifically, the distributed feedback laser can first obtain the current detection distance and current distance resolution of the frequency modulated continuous wave laser detection system. Afterwards, the distributed feedback laser can compare the current detection distance with a preset detection distance threshold, and can compare the current distance resolution with a preset distance resolution threshold.

[0036] If the current detection distance is less than the preset detection distance threshold, and the current distance resolution is greater than the preset distance resolution threshold, a distributed feedback laser generates a linear chirp light signal according to the modulation current in a step frequency modulation (SFM) manner; if the current detection distance is greater than or equal to the detection distance threshold, and the current distance resolution is less than or equal to the distance resolution threshold, a distributed feedback laser generates a linear chirp light signal according to the modulation current in a linear frequency modulation (LFM) manner. In practical applications, both the detection distance threshold and the distance resolution threshold can be set according to actual needs.

[0037] The above gives a method for generating a linear chirp light signal by selecting different methods according to the current detection distance and current distance resolution of the frequency modulated continuous wave laser detection system. When the linear chirp light signal is generated according to the modulation current using the step frequency modulation method, the response width of the two-dimensional matrix detector array can be better utilized (the response width of the two-dimensional matrix detector array is mainly determined by the dead time of each single-photon avalanche photodiode, usually between 3 and 5 MHz). When the linear frequency modulation method is used to generate the linear chirp light signal according to the modulation current, the process of generating the linear chirp light signal can be made simpler and faster.

[0038] In step d, a first laser signal is generated according to the linear chirped optical signal by a signal beam splitter, and the first laser signal is output to a signal circulator.

[0039] In this implementation, after the distributed feedback laser outputs the linear chirped optical signal to the signal beam splitter, the signal beam splitter can generate a first laser signal according to the linear chirped optical signal, and output the first laser signal to the signal circulator.

[0040] Specifically, the linear chirp optical signal can be split by a signal beam splitter to obtain two optical signals, the first optical signal can be output as a first laser signal to a signal circulator, and the second optical signal can be output as a reference signal to a mixer of a frequency modulated continuous wave laser detection system. The mixer is used to perform beat frequency processing on the reference signal and the echo signal, thereby realizing demodulation of the received second laser signal.

[0041] In step e, a first laser signal is transmitted to an underwater target through a signal circulator.

[0042] In this implementation, after the signal beam splitter outputs the first laser signal to the signal circulator, the first laser signal may be emitted to the underwater target through the signal circulator.

[0043] The signal circulator is also used to receive the second laser signal, and is also used to isolate the first laser signal from the second laser signal.

[0044] In S102 , second laser signals with different frequencies are received by a plurality of single-photon avalanche photodiodes.

[0045] In the embodiment of the present application, the second laser signal is a signal generated by the first laser signal being emitted to the underwater target and then reflected to multiple single-photon avalanche photodiodes. The frequencies of the second laser signals received by each single-photon avalanche photodiode are not completely the same.

[0046] In a possible implementation, the signal receiving end may further include a signal circulator. The signal circulator may receive second laser signals of different frequencies and output second laser signals of different frequencies to the two-dimensional matrix detector array. Afterwards, each single-photon avalanche photodiode in the two-dimensional matrix detector array may receive a second laser signal of one frequency.

[0047] In a possible implementation, before receiving the second laser signals of different frequencies through multiple single-photon avalanche photodiodes, the two-dimensional matrix detector array can be adjusted by performing steps e to g through a frequency modulated continuous wave laser detection system to improve the quality of the acquired second laser signal. The details are as follows: In step e, the minimum value of the light intensity requirement range of the frequency modulated continuous wave laser detection system and the preset incident angle of the second laser signal are obtained.

[0048] In this implementation, the frequency modulated continuous wave laser detection system can obtain the minimum value of the light intensity requirement range of the frequency modulated continuous wave laser detection system and the preset incident angle of the second laser signal, wherein the light intensity requirement range of the frequency modulated continuous wave laser detection system and the preset incident angle of the second laser signal can both be input into the frequency modulated continuous wave laser detection system by the user.

[0049] In step f, a first spacing between each first detector array and a second spacing between each second detector array are determined according to a minimum value of the light intensity requirement range and a preset incident angle.

[0050] In this implementation, after obtaining the minimum value of the light intensity requirement range and the preset incident angle of the second laser signal, the frequency modulated continuous wave laser detection system can determine the first spacing between each first detector array and the second spacing between each second detector array.

[0051] Specifically, the frequency modulated continuous wave laser detection system can determine the first spacing between each first detector array and the second spacing between each second detector array by the following formula:

[0052] in, is the minimum value of the light intensity requirement range, and are respectively represented as a first spacing between each first detector array and a second spacing between each second detector array, It is represented as a preset incident angle of the second laser signal.

[0053] See also Figure 3 , Figure 3 This is a schematic diagram of a preset incident angle of a laser signal provided in an embodiment of the present application. and Figure 3 The θ and α in correspond to each other.

[0054] In step g, the pitch of the two-dimensional matrix detector array is adjusted according to the first pitch and the second pitch.

[0055] In this implementation, after determining the first spacing and the second spacing, the frequency modulated continuous wave laser detection system can adjust the spacing of the two-dimensional matrix detector array according to the first spacing and the second spacing. Specifically, the frequency modulated continuous wave laser detection system can adjust the spacing between each first detector array to the first spacing, and can adjust the spacing between each second detector array to the second spacing.

[0056] Through the above method, the two-dimensional matrix detector array can be adjusted, so as to improve the quality of the acquired second laser signal, and further improve the accuracy of the distance detection of the underwater target.

[0057] In S103, two-dimensional discrete synthesis processing is performed on the second laser signals of different frequencies to obtain target echo signals.

[0058] In an embodiment of the present application, after receiving second laser signals of different frequencies through multiple single-photon avalanche photodiodes, the frequency-modulated continuous-wave laser detection system can perform two-dimensional discrete synthesis processing on the second laser signals of different frequencies to obtain target echo signals.

[0059] In a possible implementation, the signal receiving end of the frequency modulated continuous wave laser detection system further includes a phase shifter and a beam combiner. Based on this, each second laser signal can be subjected to phase distortion compensation processing by the phase shifter, and then each second laser signal subjected to phase distortion compensation processing can be subjected to optical wave beam combining processing by the beam combiner to obtain a target echo signal.

[0060] In S104, the distance between the underwater target and the FMCW laser detection system is determined according to the target echo signal.

[0061] In the embodiment of the present application, after the target echo signal is obtained, the distance between the underwater target and the frequency modulated continuous wave laser detection system can be determined according to the target echo signal.

[0062] Specifically, the target echo signal can be received by the mixer of the frequency modulated continuous wave laser detection system, and the beat frequency processing can be performed according to the target echo signal and the reference signal, so as to determine the distance between the underwater target and the frequency modulated continuous wave laser detection system.

[0063] It can be seen from the above that the distance detection method for underwater targets provided in the embodiment of the present application can be applied to a frequency modulated continuous wave laser detection system, wherein the signal receiving end of the frequency modulated continuous wave laser detection system includes a two-dimensional matrix detector array composed of multiple single-photon avalanche photodiodes, and the method includes: transmitting multiple first laser signals with different frequencies to the underwater target through the signal transmitting end of the frequency modulated continuous wave laser detection system; receiving second laser signals with different frequencies through multiple single-photon avalanche photodiodes, wherein the second laser signal is a signal that is reflected to multiple single-photon avalanche photodiodes after the first laser signal is emitted to the underwater target, and the frequencies of the second laser signals received by each single-photon avalanche photodiode are not exactly the same; performing two-dimensional discrete synthesis processing on the second laser signals with different frequencies to obtain a target echo signal; and determining the distance between the underwater target and the frequency modulated continuous wave laser detection system according to the target echo signal. The frequency modulated continuous wave laser detection system of the present application can emit and receive multiple laser signals of different frequencies through a two-dimensional matrix detector array composed of multiple single-photon avalanche photodiodes. Therefore, the area for receiving laser signals is large, which can improve the detection distance of underwater targets, and the received laser signals have more frequencies, so the resolution of detecting underwater targets can be improved.

[0064] Based on the underwater target distance detection method provided in the above embodiment, the present application further provides an underwater target distance detection device for implementing the above method embodiment. The underwater target distance detection device is applied to a frequency modulated continuous wave laser detection system. The signal receiving end of the frequency modulated continuous wave laser detection system includes a two-dimensional matrix detector array composed of multiple single photon avalanche photodiodes. Please refer to Figure 4 , Figure 4 This is a schematic diagram of the structure of a distance detection device for an underwater target provided in an embodiment of the present application. Figure 4 As shown, the underwater target distance detection device 40 may include: a signal transmitting unit 41, a signal receiving unit 42, a signal processing unit 43 and a distance determination unit 44. Among them: The signal transmitting unit 41 is used to transmit a plurality of first laser signals with different frequencies to the underwater target through the signal transmitting end of the frequency modulated continuous wave laser detection system.

[0065] The signal receiving unit 42 is used to receive second laser signals of different frequencies through multiple single-photon avalanche photodiodes; the second laser signal is a signal that is reflected to multiple single-photon avalanche photodiodes after the first laser signal is emitted to the underwater target, and the frequencies of the second laser signals received by each single-photon avalanche photodiode are not exactly the same.

[0066] The signal processing unit 43 is used to perform two-dimensional discrete synthesis processing on the second laser signals of different frequencies to obtain target echo signals.

[0067] The distance determination unit 44 is used to determine the distance between the underwater target and the FMCW laser detection system according to the target echo signal.

[0068] Optionally, the signal transmitting end includes a signal generator, a signal driver, a distributed feedback laser, a signal beam splitter and a signal circulator. The signal transmitting unit 41 is specifically used for: Outputting a modulation signal to a signal driver via a signal generator; Outputting a modulation current to the distributed feedback laser according to the modulation signal through a signal driver; Generate a linear chirp optical signal according to a modulation current through a distributed feedback laser, and output the linear chirp optical signal to a signal beam splitter; Generate a first laser signal according to the linear chirped light signal through a signal beam splitter, and output the first laser signal to a signal circulator; A first laser signal is emitted toward an underwater target through a signal circulator.

[0069] Optionally, the signal transmitting unit 41 is specifically used for: Get the current detection distance and current distance resolution of the frequency modulated continuous wave laser detection system; If the current detection distance is less than the preset detection distance threshold, and the current distance resolution is greater than the preset distance resolution threshold, a linear chirp light signal is generated according to the modulation current in a step frequency modulation manner by a distributed feedback laser; If the current detection distance is greater than or equal to the detection distance threshold, and the current distance resolution is less than or equal to the distance resolution threshold, a linear chirp light signal is generated by a distributed feedback laser according to a modulation current in a linear frequency modulation manner.

[0070] Optionally, the signal receiving unit 42 is specifically used for: receiving second laser signals of different frequencies through a signal circulator, and outputting second laser signals of different frequencies to a two-dimensional matrix detector array; A second laser signal of one frequency is received by each single photon avalanche photodiode.

[0071] Optionally, the two-dimensional matrix detector array includes a first detector array in a first direction and a second detector array in a second direction, and the number of single-photon avalanche photodiodes included in the first detector array is the same as the number of single-photon avalanche photodiodes included in the second detector array.

[0072] Optionally, the underwater target distance detection device 40 may further include an array adjustment unit. The array adjustment unit is specifically used for: Obtaining a minimum value of a light intensity requirement range of a frequency modulated continuous wave laser detection system and a preset incident angle of a second laser signal; Determine a first spacing between each first detector array and a second spacing between each second detector array according to a minimum value of a light intensity requirement range and a preset incident angle; The pitch of the two-dimensional matrix detector array is adjusted according to the first pitch and the second pitch.

[0073] Optionally, the signal receiving end further includes a phase shifter and a beam combiner. The signal processing unit 43 is specifically used for: Performing phase distortion compensation processing on each second laser signal through a phase shifter; The beam combiner performs light wave combining processing on each second laser signal after the phase distortion compensation processing to obtain a target echo signal.

[0074] See also Figure 5 , Figure 5 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. Figure 5 As shown, the electronic device 5 provided in this embodiment may include: a processor 50, a memory 51, and a computer program 52 stored in the memory 51 and executable on the processor 50, such as a program corresponding to the underwater target distance detection method. When the processor 50 executes the computer program 52, the steps in the above-mentioned embodiment of the underwater target distance detection method are implemented, such as Figure 1 Alternatively, when the processor 50 executes the computer program 52, the functions of each module / unit in the above-mentioned underwater target distance detection device embodiment are realized, for example Figure 4 The functions of the units 41 to 44 are shown.

[0075] Exemplarily, the computer program 52 may be divided into one or more modules / units, one or more modules / units are stored in the memory 51 and executed by the processor 50 to complete the present application. The one or more modules / units may be a series of computer program instruction segments that can complete specific functions, and the instruction segments are used to describe the execution process of the computer program 52 in the electronic device 5. For example, the computer program 52 may be divided into a signal transmitting unit 41, a signal receiving unit 42, a signal processing unit 43, and a distance determining unit 44. For the specific functions of each unit, please refer to Figure 4 The relevant descriptions in the corresponding embodiments are not repeated here.

[0076] Those skilled in the art will understand that Figure 5 The electronic device 5 is merely an example and does not constitute a limitation on the electronic device 5 , and may include more or less components than those shown in the figure, or may combine certain components, or may have different components.

[0077] The processor 50 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc.

[0078] The memory 51 may be an internal storage unit of the electronic device 5, such as a hard disk or memory of the electronic device 5. The memory 51 may also be an external storage device of the electronic device 5, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, or a flash card, etc., equipped on the electronic device 5. Further, the memory 51 may also include both an internal storage unit of the electronic device 5 and an external storage device. The memory 51 is used to store computer programs and other programs and data required by the electronic device. The memory 51 may also be used to temporarily store data that has been output or is to be output.

[0079] Those skilled in the art can clearly understand that, for the convenience and simplicity of description, only the division of the above-mentioned functional units is used as an example for illustration. In actual applications, the above-mentioned functions can be assigned to different functional units as needed, that is, the internal structure of the underwater target distance detection device can be divided into different functional units to complete all or part of the functions described above. The functional units in the embodiment can be integrated into a processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0080] An embodiment of the present application further provides a computer-readable storage medium, in which a computer program is stored. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments can be implemented.

[0081] An embodiment of the present application provides a computer program product. When the computer program product is executed on a terminal device, the terminal device implements the steps in the above-mentioned various method embodiments.

[0082] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0083] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0084] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A method for detecting the distance of an underwater target, characterized in that: Applied to a frequency modulated continuous wave laser detection system, the signal receiving end of the frequency modulated continuous wave laser detection system includes a two-dimensional matrix detector array composed of multiple single photon avalanche photodiodes, and the method includes: Transmitting a plurality of first laser signals of different frequencies to the underwater target through a signal transmitting end of the frequency modulated continuous wave laser detection system; receiving second laser signals of different frequencies through the multiple single-photon avalanche photodiodes; the second laser signal is a signal reflected by the multiple single-photon avalanche photodiodes after the first laser signal is emitted to the underwater target, and the frequencies of the second laser signals received by the respective single-photon avalanche photodiodes are not completely the same; Performing two-dimensional discrete synthesis processing on the second laser signals of different frequencies to obtain target echo signals; The distance between the underwater target and the frequency modulated continuous wave laser detection system is determined according to the target echo signal.

2. The method according to claim 1, characterized in that The signal transmitting end includes a signal generator, a signal driver, a distributed feedback laser, a signal beam splitter and a signal circulator, and the signal transmitting end of the frequency modulated continuous wave laser detection system transmits a plurality of first laser signals of different frequencies to the underwater target, including: Outputting a modulation signal to the signal driver through the signal generator; Outputting a modulation current to the distributed feedback laser according to the modulation signal through the signal driver; generating a linear chirped optical signal according to the modulation current through the distributed feedback laser, and outputting the linear chirped optical signal to the signal beam splitter; generating the first laser signal according to the linear chirped optical signal through the signal beam splitter, and outputting the first laser signal to the signal circulator; The first laser signal is transmitted to the underwater target through the signal circulator.

3. The method according to claim 2, characterized in that The step of generating a linear chirp optical signal by the distributed feedback laser according to the modulation current comprises: Obtaining the current detection distance and current distance resolution of the frequency modulated continuous wave laser detection system; If the current detection distance is less than a preset detection distance threshold, and the current distance resolution is greater than a preset distance resolution threshold, the linear chirp optical signal is generated by the distributed feedback laser according to the modulation current in a step frequency modulation manner; If the current detection distance is greater than or equal to the detection distance threshold, and the current distance resolution is less than or equal to the distance resolution threshold, the linear chirp light signal is generated by the distributed feedback laser in a linear frequency modulation manner according to the modulation current.

4. The method according to claim 2, characterized in that: The signal receiving end further includes the signal circulator, and the receiving of the second laser signals of different frequencies through the multiple single-photon avalanche photodiodes includes: receiving the second laser signals of different frequencies through the signal circulator, and outputting the second laser signals of different frequencies to the two-dimensional matrix detector array; The second laser signal of one frequency is received by each of the single-photon avalanche photodiodes.

5. The method according to claim 1, characterized in that The two-dimensional matrix detector array includes a first detector array in a first direction and a second detector array in a second direction, and the number of the single-photon avalanche photodiodes included in the first detector array is the same as the number of the single-photon avalanche photodiodes included in the second detector array.

6. The method according to claim 5, characterized in that Before receiving the second laser signals with different frequencies through the multiple single-photon avalanche photodiodes, the method further includes: Obtaining a minimum value of a light intensity requirement range of the frequency modulated continuous wave laser detection system and a preset incident angle of the second laser signal; Determining a first spacing between each of the first detector arrays and a second spacing between each of the second detector arrays according to a minimum value of the light intensity requirement range and the preset incident angle; The pitch of the two-dimensional matrix detector array is adjusted according to the first pitch and the second pitch.

7. The method according to claim 1, characterized in that The signal receiving end further includes a phase shifter and a beam combiner; the two-dimensional discrete synthesis processing of the second laser signals of different frequencies to obtain the target echo signal includes: Performing phase distortion compensation processing on each of the second laser signals by using the phase shifter; The beam combiner performs optical wave combining processing on each of the second laser signals after the phase distortion compensation processing to obtain the target echo signal.

8. A distance detection device for underwater targets, characterized in that: Applied to a frequency modulated continuous wave laser detection system, the signal receiving end of the frequency modulated continuous wave laser detection system includes a two-dimensional matrix detector array composed of multiple single photon avalanche photodiodes, and the device includes: A signal transmitting unit, used for transmitting a plurality of first laser signals of different frequencies to an underwater target through a signal transmitting end of the frequency modulated continuous wave laser detection system; A signal receiving unit, configured to receive second laser signals of different frequencies through the multiple single-photon avalanche photodiodes; the second laser signal is a signal generated by the first laser signal being emitted to the underwater target and then reflected to the multiple single-photon avalanche photodiodes, and the frequencies of the second laser signals received by the respective single-photon avalanche photodiodes are not completely the same; A signal processing unit, used for performing two-dimensional discrete synthesis processing on the second laser signals of different frequencies to obtain a target echo signal; The distance determination unit is used to determine the distance between the underwater target and the frequency modulated continuous wave laser detection system according to the target echo signal.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the underwater target distance detection method according to any one of claims 1 to 7 are implemented.

10. A computer program product, characterized in that When the computer program product is executed by a processor, each step of the underwater target distance detection method according to any one of claims 1 to 7 is implemented.

Images