Method, device, electronic device and program product for detecting distance of underwater target

Abstract

This application is applicable to the field of ranging technology, and provides a method, device, electronic device and program product for detecting the distance of underwater targets. The method is 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. The method includes: transmitting multiple first laser signals with different frequencies to an underwater target through the signal transmitting end of the frequency-modulated continuous-wave laser detection system; receiving second laser signals with different frequencies through the multiple single-photon avalanche photodiodes; 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 this application can transmit and receive multiple laser signals with different frequencies, so it can improve the detection distance and resolution of underwater targets.

Description

Technical Field

[0001] This application belongs to the technical field of ranging, and particularly relates to a method, device, electronic device and program product for detecting the distance of underwater targets. Background Art

[0002] At present, the detection technologies for underwater targets mainly include underwater acoustic detection technology and laser detection technology. Compared with underwater acoustic detection technology, laser detection technology has the advantages of low time delay and strong anti-interference ability. The currently commonly used laser detection system is the Time of Flight (TOF) underwater laser detection system. However, since light waves attenuate severely when transmitting underwater, 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 usually can only emit 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 this application provide a method, device, electronic device and program product for detecting the distance of underwater targets, so as to solve the technical problems of short detection distance and low resolution in detecting underwater targets in the prior art.

[0004] In a first aspect, the embodiments of this application provide a method for detecting the distance of an underwater target, which 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. The method includes:

[0005] Transmitting 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;

[0006] Receiving second laser signals with different frequencies through the multiple single-photon avalanche photodiodes; the second laser signals are the signals that the first laser signals are reflected to the multiple single-photon avalanche photodiodes after being transmitted to the underwater target, and the frequencies of the second laser signals received by each of the single-photon avalanche photodiodes are not completely the same;

[0007] Performing two-dimensional discrete synthesis processing on the second laser signals with different frequencies to obtain a target echo signal;

[0008] Determining the distance between the underwater target and the frequency-modulated continuous-wave laser detection system according to the target echo signal.

[0009] Optionally, the signal transmitting end includes a signal generator, a signal driver, a distributed feedback laser, a signal beam splitter, and a signal circulator. Transmitting multiple first laser signals with different frequencies to an underwater target through the signal transmitting end of the frequency-modulated continuous-wave laser detection system includes:

[0010] Outputting a modulation signal from the signal generator to the signal driver;

[0011] Outputting a modulation current from the signal driver to the distributed feedback laser according to the modulation signal;

[0012] Generating a linearly chirped optical signal by the distributed feedback laser according to the modulation current, and outputting the linearly chirped optical signal to the signal beam splitter;

[0013] Generating the first laser signal by the signal beam splitter according to the linearly chirped optical signal, and outputting the first laser signal to the signal circulator;

[0014] Transmitting the first laser signal to the underwater target through the signal circulator.

[0015] Optionally, generating the linearly chirped optical signal by the distributed feedback laser according to the modulation current includes:

[0016] Obtaining the current detection distance and the current distance resolution of the frequency-modulated continuous-wave laser detection system;

[0017] 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, generating the linearly chirped optical signal by the distributed feedback laser in a stepped frequency modulation manner according to the modulation current;

[0018] 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, generating the linearly chirped optical signal by the distributed feedback laser in a linear frequency modulation manner according to the modulation current.

[0019] Optionally, the signal receiving end further includes the signal circulator. Receiving different-frequency second laser signals through the multiple single-photon avalanche photodiodes includes:

[0020] Receiving each different-frequency second laser signal through the signal circulator, and outputting each different-frequency second laser signal to the two-dimensional matrix detector array;

[0021] Receiving one frequency of the second laser signal through each single-photon avalanche photodiode.

[0022] 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.

[0023] Optionally, before receiving the second laser signals of different frequencies through the plurality of single-photon avalanche photodiodes, it further includes:

[0024] Obtaining 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;

[0025] Determining a first spacing between the first detector arrays and a second spacing between the second detector arrays according to the minimum value of the light intensity requirement range and the preset incident angle;

[0026] Adjusting the spacing of the two-dimensional matrix detector array according to the first spacing and the second spacing.

[0027] 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 a target echo signal includes:

[0028] Performing phase distortion compensation processing on each of the second laser signals through the phase shifter;

[0029] Performing optical wave beam combination processing on each of the second laser signals after the phase distortion compensation processing through the beam combiner to obtain the target echo signal.

[0030] In a second aspect, an underwater target distance detection device provided by an embodiment of the present application is 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 a plurality of single-photon avalanche photodiodes. The device includes:

[0031] A signal transmitting unit, configured 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;

[0032] A signal receiving unit, configured to receive second laser signals of different frequencies through the plurality of single-photon avalanche photodiodes; the second laser signals are signals reflected from the first laser signals to the underwater target and then to the plurality of single-photon avalanche photodiodes, and the frequencies of the second laser signals received by each of the single-photon avalanche photodiodes are not completely the same;

[0033] A signal processing unit, configured to perform two-dimensional discrete synthesis processing on the second laser signals of different frequencies to obtain a target echo signal;

[0034] A distance determination unit, configured to determine the distance between the underwater target and the frequency-modulated continuous-wave laser detection system according to the target echo signal.

[0035] In a third aspect, an embodiment of the present application provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the method for detecting the distance of an underwater target as described in the first aspect are implemented.

[0036] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium. The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method for detecting the distance of an underwater target as described in the first aspect are implemented.

[0037] In a fifth aspect, an embodiment of the present application provides a computer program. When the computer program runs on an electronic device, the electronic device is caused to execute the steps of the method for detecting the distance of an underwater target as described in the first aspect.

[0038] The method, device, electronic device, and program product for detecting the distance of an underwater target provided by the embodiments of the present application have the following beneficial effects:

[0039] The method for detecting the distance of an underwater target provided by the embodiments of the present application can be applied to a frequency-modulated continuous-wave laser detection system. Among them, the signal receiving end of the frequency-modulated continuous-wave laser detection system includes a two-dimensional matrix detector array composed of a plurality of single-photon avalanche photodiodes. The method includes: transmitting 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; receiving second laser signals of different frequencies through a plurality of single-photon avalanche photodiodes, where the second laser signal is the signal reflected from the first laser signal to the underwater target and then to the plurality of single-photon avalanche photodiodes, 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; determining the distance between the underwater target and the frequency-modulated continuous-wave laser detection system according to the target echo signal. Through the frequency-modulated continuous-wave laser detection system of the present application, a plurality of laser signals of different frequencies can be transmitted and received through a two-dimensional matrix detector array composed of a plurality of single-photon avalanche photodiodes. Therefore, the area for receiving laser signals is large, the detection distance of underwater targets can be improved, and the frequencies of the received laser signals are relatively many. Therefore, the resolution for detecting underwater targets can be improved. Description of the Drawings

[0040] To more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0041] Figure 1 It is a flowchart for implementing a method for detecting the distance of an underwater target provided by an embodiment of the present application;

[0042] Figure 2 It is a schematic structural diagram of a two-dimensional matrix detector array provided by an embodiment of the present application;

[0043] Figure 3 It is a schematic diagram of a preset incident angle of a laser signal provided by an embodiment of the present application;

[0044] Figure 4 It is a schematic structural diagram of a device for detecting the distance of an underwater target provided by an embodiment of the present application;

[0045] Figure 5 It is a schematic structural diagram of an electronic device provided by an embodiment of the present application. Specific embodiments

[0046] 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, rather than to limit the present application. In the description of the embodiments of the present application, unless otherwise specified, "a plurality" means two or more than two, "at least one", "one or more" means one, two or more than two. 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 quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features.

[0047] The reference to "one embodiment" or "some embodiments" etc. in this specification means that a specific feature, structure, or characteristic described in conjunction with the embodiment is included in one or more embodiments of the present application. Thus, the statements "in one embodiment", "in some embodiments", "in other some embodiments", "in still other embodiments" etc. that appear in different places in this specification are not necessarily all referring to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "comprise", "include", "have" and their variants all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0048] The execution subject of the underwater target distance detection method provided by the embodiments of the present application can be a frequency-modulated continuous-wave laser detection system. Among them, 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, each step of the underwater target distance detection method provided by the embodiments of the present application can be executed by the frequency-modulated continuous-wave laser detection system provided by the embodiments of the present application, so as to improve the detection distance and resolution of underwater targets.

[0049] Please refer to Figure 1 , Figure 1 which is a flowchart of the implementation of a method for detecting the distance of an underwater target provided by the embodiments of the present application. The method for detecting the distance of an underwater target provided by the embodiments 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.

[0050] Please refer to Figure 2 , Figure 2 which is a schematic structural diagram of a two-dimensional matrix detector array provided by the embodiments of the present application. As Figure 2 shown, the two-dimensional matrix detector array can include a first detector array in the first direction and a second detector array in the second direction. Among them, 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. As Figure 2 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.

[0051] In the two-dimensional matrix detector array provided by the embodiments of the present application, each single-photon avalanche photodiode can receive a laser signal of a preset frequency, and the frequencies of the laser signals received by each single-photon avalanche photodiode in the two-dimensional matrix detector array are not completely the same, so the resolution of detecting underwater targets can be improved.

[0052] In practical applications, even if only a single photon is incident on the single-photon avalanche photodiode, it will cause a large current in the single-photon avalanche photodiode 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 an underwater target, the two-dimensional matrix detector composed of multiple single-photon avalanche photodiodes can also improve the detection distance of the underwater target.

[0053] Based on the two-dimensional matrix detector array provided above, as Figure 1 shown, a method for detecting the distance of an underwater target provided by an embodiment of the present application may include steps S101 to S104, which are described in detail as follows:

[0054] In S101, a plurality of first laser signals with different frequencies are emitted to the underwater target through the signal transmitting end of the frequency-modulated continuous-wave laser detection system.

[0055] 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 with different frequencies can be emitted to the underwater target through the signal transmitting end of the frequency-modulated continuous-wave laser detection system.

[0056] Among them, the specific frequencies of the respective first laser signals can be set according to actual requirements.

[0057] In a possible implementation manner, 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 can be used to implement the emission of 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. The details are as follows:

[0058] In step a, a modulation signal is output from the signal generator to the signal driver.

[0059] In this implementation manner, when it is necessary to emit 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, a modulation signal can be first output from the signal generator to the signal driver. Among them, the modulation signal can be used to generate a modulation current. Exemplarily, the modulation signal can be a triangular wave signal.

[0060] In step b, the signal driver outputs a modulation current to the distributed feedback laser according to the modulation signal.

[0061] In this implementation manner, 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.

[0062] In step c, the distributed feedback laser generates a linear chirped optical signal according to the modulation current and outputs the linear chirped optical signal to the signal beam splitter.

[0063] In this implementation, the laser diode in a Distributed Feedback (DFB) laser outputs a laser signal with a single frequency. Under the modulation of a modulation current, the frequency of this laser signal will sweep periodically within a bandwidth range (such as from a low frequency to a high frequency and then back to a low frequency), forming a linearly chirped optical signal.

[0064] In practical applications, the output wavelength of a distributed feedback laser is very sensitive to temperature. To ensure the accuracy and repeatability of frequency modulation (chirping) in a frequency-modulated continuous-wave (FMCW) 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 environmental temperature fluctuations and ensure that the linear chirping characteristics of the linearly chirped optical signal remain good.

[0065] In a possible implementation, the distributed feedback laser can select different methods to generate a linearly chirped optical signal according to the actual situation. Specifically, the distributed feedback laser can first obtain the current detection distance and the current distance resolution of the frequency-modulated continuous-wave laser detection system. After that, the distributed feedback laser can compare the current detection distance with a preset detection distance threshold and can also compare the current distance resolution with a preset distance resolution threshold.

[0066] 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, the distributed feedback laser generates a linearly chirped optical 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, the distributed feedback laser generates a linearly chirped optical 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 requirements.

[0067] The above gives a method for selecting different ways to generate a linearly chirped optical signal according to the current detection distance and the current distance resolution of the frequency-modulated continuous-wave laser detection system. When generating a linearly chirped optical signal according to the modulation current in a step frequency modulation manner, it can make better use of the response width of the two-dimensional matrix detector array (the response width of the two-dimensional matrix detector array is mainly determined by the dead time of each single-photon avalanche photodiode and is usually between 3 and 5 MHz). When generating a linearly chirped optical signal according to the modulation current in a linear frequency modulation manner, the process of generating the linearly chirped optical signal can be made simpler and faster.

[0068] In step d, a first laser signal is generated based on the linearly chirped optical signal by a signal beam splitter, and the first laser signal is output to a signal circulator.

[0069] In this implementation, after the distributed feedback laser outputs the linearly chirped optical signal to the signal beam splitter, the signal beam splitter can generate a first laser signal based on the linearly chirped optical signal and output the first laser signal to the signal circulator.

[0070] Specifically, the linearly chirped optical signal can be split by the signal beam splitter to obtain two parts of optical signals. The first part of the optical signal can be output as the first laser signal to the signal circulator, and the second part of the optical signal can be output as a reference signal to the mixer of the frequency-modulated continuous-wave laser detection system. Among them, the mixer is used to perform beat frequency processing on the reference signal and the echo signal, so as to realize the demodulation of the received second laser signal.

[0071] In step e, the first laser signal is transmitted to the underwater target through the signal circulator.

[0072] In this implementation, after the signal beam splitter outputs the first laser signal to the signal circulator, the first laser signal can be transmitted to the underwater target through the signal circulator.

[0073] Among them, the signal circulator is also used to receive the second laser signal and isolate the first laser signal and the second laser signal.

[0074] In S102, different frequencies of the second laser signal are received by a plurality of single-photon avalanche photodiodes.

[0075] In the embodiments of the present application, the second laser signal is the signal reflected from the first laser signal transmitted to the underwater target to the plurality of single-photon avalanche photodiodes. The frequencies of the second laser signals received by each single-photon avalanche photodiode are not exactly the same.

[0076] In a possible implementation, the signal receiving end may further include a signal circulator. Each different frequency of the second laser signal can be received by the signal circulator and output to the two-dimensional matrix detector array. Then, each single-photon avalanche photodiode in the two-dimensional matrix detector array can receive a second laser signal of one frequency.

[0077] In a possible implementation, before receiving different frequencies of the second laser signal by a plurality of single-photon avalanche photodiodes, steps e to g can be performed by the frequency-modulated continuous-wave laser detection system to adjust the two-dimensional matrix detector array to improve the quality of the obtained second laser signal. Details are as follows:

[0078] In step e, 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.

[0079] 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, where both 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 be input by the user into the frequency-modulated continuous-wave laser detection system.

[0080] In step f, determine the first spacing between each first detector array and the second spacing between each second detector array according to the minimum value of the light intensity requirement range and the preset incident angle.

[0081] In this implementation, after the frequency-modulated continuous-wave laser detection system obtains the minimum value of the light intensity requirement range and the preset incident angle of the second laser signal, it can determine the first spacing between each first detector array and the second spacing between each second detector array.

[0082] 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 through the following formula:

[0083]

[0084] where, is the minimum value of the light intensity requirement range, and respectively represent the first spacing between each first detector array and the second spacing between each second detector array, represents the preset incident angle of the second laser signal.

[0085] Please refer to Figure 3 , Figure 3 which is a schematic diagram of the preset incident angle of a laser signal provided by an embodiment of the present application. In the above formula corresponds to θ and Figure 3 α in.

[0086] In step g, adjust the spacing of the two-dimensional matrix detector array according to the first spacing and the second spacing.

[0087] In this implementation manner, 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.

[0088] Through the above method, the two-dimensional matrix detector array can be adjusted, so that the quality of the obtained second laser signal can be improved, and further the accuracy of the distance detection of the underwater target can be improved.

[0089] In S103, two-dimensional discrete synthesis processing is performed on the second laser signals with different frequencies to obtain a target echo signal.

[0090] In the embodiments of the present application, after receiving the second laser signals with 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 with different frequencies to obtain a target echo signal.

[0091] In a possible implementation manner, 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, the phase distortion compensation processing can be performed on each second laser signal through the phase shifter, and then the optical wave beam combination processing can be performed on each second laser signal after the phase distortion compensation processing through the beam combiner to obtain a target echo signal.

[0092] In S104, according to the target echo signal, the distance between the underwater target and the frequency-modulated continuous-wave laser detection system is determined.

[0093] In the embodiments of the present application, after obtaining the target echo signal, the distance between the underwater target and the frequency-modulated continuous-wave laser detection system can be determined according to the target echo signal.

[0094] Specifically, the target echo signal can be received by the mixer of the frequency-modulated continuous-wave laser detection system, and beat frequency processing can be performed according to the target echo signal and the reference signal, so as to further determine the distance between the underwater target and the frequency-modulated continuous-wave laser detection system.

[0095] As can be seen above, the distance detection method for underwater targets provided by the embodiments of the present application can be applied to a frequency-modulated continuous-wave laser detection system. Among them, 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. The method includes: transmitting multiple first laser signals with different frequencies to an 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, where the second laser signal is the signal reflected from the first laser signal to the underwater target and then to the multiple single-photon avalanche photodiodes, 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. Through the frequency-modulated continuous-wave laser detection system of the present application, multiple laser signals with different frequencies can be transmitted and received through a two-dimensional matrix detector array composed of multiple single-photon avalanche photodiodes. Therefore, the area for receiving laser signals is large, the detection distance for underwater targets can be increased, and the frequencies of the received laser signals are relatively many. Therefore, the resolution for detecting underwater targets can be improved.

[0096] Based on the distance detection method for underwater targets provided in the above embodiments, the embodiments of the present application further provide a distance detection device for underwater targets to implement the above method embodiments. The distance detection device for underwater targets is 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. Please refer to Figure 4 , Figure 4 which is a schematic structural diagram of a distance detection device for underwater targets provided by the embodiments of the present application. As Figure 4 shown, the distance detection device 40 for underwater targets may include: a signal transmitting unit 41, a signal receiving unit 42, a signal processing unit 43, and a distance determining unit 44. Among them:

[0097] The signal transmitting unit 41 is configured to transmit multiple first laser signals with different frequencies to an underwater target through the signal transmitting end of the frequency-modulated continuous-wave laser detection system.

[0098] The signal receiving unit 42 is configured to receive second laser signals with different frequencies through multiple single-photon avalanche photodiodes; the second laser signal is the signal reflected from the first laser signal to the underwater target and then to the multiple single-photon avalanche photodiodes, and the frequencies of the second laser signals received by each single-photon avalanche photodiode are not exactly the same.

[0099] The signal processing unit 43 is configured to perform two-dimensional discrete synthesis processing on the second laser signals with different frequencies to obtain a target echo signal.

[0100] The distance determination unit 44 is configured to determine the distance between the underwater target and the frequency-modulated continuous-wave laser detection system according to the target echo signal.

[0101] 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 configured to:

[0102] Output a modulation signal to the signal driver through the signal generator;

[0103] Output a modulation current to the distributed feedback laser through the signal driver according to the modulation signal;

[0104] Generate a linear chirp optical signal according to the modulation current through the distributed feedback laser, and output the linear chirp optical signal to the signal beam splitter;

[0105] Generate a first laser signal according to the linear chirp optical signal through the signal beam splitter, and output the first laser signal to the signal circulator;

[0106] Transmit the first laser signal to the underwater target through the signal circulator.

[0107] Optionally, the signal transmitting unit 41 is specifically configured to:

[0108] Obtain the current detection distance and the current distance resolution of the frequency-modulated continuous-wave laser detection system;

[0109] 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, generate a linear chirp optical signal according to the modulation current through the distributed feedback laser in a stepped frequency modulation manner;

[0110] 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, generate a linear chirp optical signal according to the modulation current through the distributed feedback laser in a linear frequency modulation manner.

[0111] Optionally, the signal receiving unit 42 is specifically configured to:

[0112] Receive second laser signals of different frequencies through the signal circulator, and output the second laser signals of different frequencies to the two-dimensional matrix detector array;

[0113] Receive a second laser signal of one frequency through each single-photon avalanche photodiode.

[0114] 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.

[0115] Optionally, the distance detection device 40 for underwater targets may further include an array adjustment unit. Wherein:

[0116] The array adjustment unit is specifically configured to:

[0117] 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;

[0118] Determine the first spacing between the first detector arrays and the second spacing between the second detector arrays according to the minimum value of the light intensity requirement range and the preset incident angle;

[0119] Adjust the spacing of the two-dimensional matrix detector array according to the first spacing and the second spacing.

[0120] Optionally, the signal receiving end further includes a phase shifter and a beam combiner. The signal processing unit 43 is specifically configured to:

[0121] Perform phase distortion compensation processing on each second laser signal through the phase shifter;

[0122] Perform optical wave beam combination processing on the phase distortion compensation processed second laser signals through the beam combiner to obtain the target echo signal.

[0123] Please refer to Figure 5 , Figure 5 which is a schematic structural diagram of an electronic device provided by an embodiment of the present application. As Figure 5 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 method for detecting the distance of an underwater target. When the processor 50 executes the computer program 52, the steps in the above-described embodiment of the method for detecting the distance of an underwater target are implemented, such as Figure 1 the S101~S104 shown. Alternatively, when the processor 50 executes the computer program 52, the functions of the various modules / units in the above-described embodiment of the distance detection device for underwater targets are implemented, such as Figure 4 the functions of the units 41~44 shown.

[0124] Exemplarily, the computer program 52 can 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. One or more modules / units can be a series of computer program instruction segments capable of completing 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 can 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, which will not be elaborated here.

[0125] Those skilled in the art can understand that Figure 5 merely examples of the electronic device 5, which do not constitute a limitation on the electronic device 5, and may include more or fewer components than shown in the figure, or combine certain components, or different components.

[0126] The processor 50 can be a central processing unit (CPU), or can also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc.

[0127] The memory 51 can be an internal storage unit of the electronic device 5, such as the hard disk or memory of the electronic device 5. The memory 51 can 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 equipped on the electronic device 5. Further, the memory 51 can also include both the internal storage unit and the external storage device of the electronic device 5. The memory 51 is used to store computer programs and other programs and data required by the electronic device. The memory 51 can also be used to temporarily store the data that has been output or will be output.

[0128] Those skilled in the art can clearly understand that, for the convenience and conciseness of description, only the division of the above functional units is used as an example. In actual applications, the above functions can be allocated to different functional units according to needs, 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. Each functional unit in the embodiment can be integrated into a processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above integrated unit can be implemented in the form of hardware or in the form of a software functional unit. In addition, the specific names of the functional units are only for the convenience of mutual distinction and do not limit the protection scope of this application. The specific working process of the units in the above system can refer to the corresponding process in the foregoing method embodiment and will not be elaborated herein.

[0129] An embodiment of the present application also 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 foregoing method embodiments can be implemented.

[0130] An embodiment of the present application provides a computer program product. When the computer program product runs on a terminal device, the terminal device implements the steps in the foregoing method embodiments.

[0131] In the above embodiments, the descriptions of the various embodiments have their own emphases. For the parts not detailed or recorded in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0132] Those of ordinary skill in the art can realize that the units and algorithm steps of the examples described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or by a combination of computer software and electronic hardware. Whether these functions are executed in hardware or software depends on the specific application and design constraints of the technical solution. A professional technician can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of this application.

[0133] The above embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit them. Although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. And these modifications or replacements do not make the essence of the corresponding technical solutions deviate 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; Determining the distance between the underwater target and the frequency modulated continuous wave laser detection system according to the target echo signal; The two-dimensional matrix detector array comprises a first detector array in a first direction and a second detector array in a second direction, wherein 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; 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; Adjusting the spacing of the two-dimensional matrix detector array according to the first spacing and the second spacing; The determining, according to the minimum value of the light intensity requirement range and the preset incident angle, a first spacing between each of the first detector arrays and a second spacing between each of the second detector arrays comprises: Determine each of the first spacings and each of the second spacings according to the minimum value of the light intensity requirement range, the preset incident angle, and a target formula; The target formula is: in, is the minimum value of the light intensity requirement range, and are the first spacings and the second spacings respectively, is the preset incident angle.

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 generating of 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 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.

6. 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; A distance determination unit, used to determine the distance between the underwater target and the FMCW laser detection system according to the target echo signal; The two-dimensional matrix detector array comprises a first detector array in a first direction and a second detector array in a second direction, wherein 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; The device also includes: An acquisition unit, used to acquire 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; a spacing determination unit, configured to determine 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; A spacing adjustment unit, configured to adjust the spacing of the two-dimensional matrix detector array according to the first spacing and the second spacing; The spacing determination unit is specifically used for: Determine each of the first spacings and each of the second spacings according to the minimum value of the light intensity requirement range, the preset incident angle, and a target formula; The target formula is: in, is the minimum value of the light intensity requirement range, and are the first spacings and the second spacings respectively, is the preset incident angle.

7. 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 in the underwater target distance detection method according to any one of claims 1 to 5 are implemented.

8. 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 5 is implemented.

Images