Signal enhancement method, device, OPA laser radar and storage medium

Abstract

The present application is applicable to the field of signal processing technology, and provides a signal enhancement method, device, OPA laser radar and storage medium. The signal enhancement method includes: obtaining a first frequency spectrum corresponding to each of N difference frequency signals for the target detection object, wherein the first frequency spectrum includes a spectrum serial number and a spectrum amplitude corresponding to the spectrum serial number, where N is an integer greater than 1; performing a dot multiplication operation on the spectrum amplitudes with the same spectrum serial number in the N first frequency spectra to obtain a second frequency spectrum with a signal-to-noise ratio of #imgabs0#, where x1 is the signal-to-noise ratio of a single first frequency spectrum; and determining the frequency of the difference frequency signal based on the second frequency spectrum. The present application can improve the accuracy of the frequency measurement results of the difference frequency signal.

Description

Technical Field

[0001] The present application belongs to the field of signal processing technology, and in particular relates to a signal enhancement method, device, OPA laser radar and storage medium. Background Art

[0002] When an optical phased array (OPA) lidar's transmitted signal propagates through space, it generates an echo signal if it encounters an obstacle. This echo signal is mixed with the current local oscillator signal to produce a difference frequency signal. The frequency of the difference frequency signal can be used to determine the distance between the obstacle and the OPA lidar. However, the echo signal often contains noise, resulting in a low signal-to-noise ratio and reducing the accuracy of the difference frequency signal's frequency measurement. Summary of the Invention

[0003] The embodiments of the present application provide a signal enhancement method, device, OPA laser radar and storage medium to improve the accuracy of the frequency measurement results of the difference frequency signal.

[0004] In a first aspect, an embodiment of the present application provides a signal enhancement method applied to an OPA laser radar, the signal enhancement method comprising:

[0005] Obtaining a first frequency spectrum corresponding to each of N difference frequency signals of the target detection object, wherein the first frequency spectrum includes a spectrum number and a spectrum amplitude corresponding to the spectrum number, where N is an integer greater than 1;

[0006] Perform a dot multiplication operation on the spectrum amplitudes of the N first frequency spectra with the same spectrum number, and obtain the signal-to-noise ratio: The second frequency spectrum of x1 is the signal-to-noise ratio of the single first frequency spectrum;

[0007] The frequency of the difference frequency signal is determined according to the second frequency spectrum.

[0008] In a second aspect, an embodiment of the present application provides a signal enhancement device, which is applied to an OPA laser radar. The signal enhancement device includes:

[0009] A frequency spectrum acquisition module is configured to acquire a first frequency spectrum corresponding to each of N difference frequency signals of the target detection object, wherein the first frequency spectrum includes a spectrum number and a spectrum amplitude corresponding to the spectrum number, where N is an integer greater than 1;

[0010] The dot multiplication operation module is used to perform dot multiplication operation on the spectrum amplitudes with the same spectrum sequence number in the N first frequency spectra to obtain a signal-to-noise ratio of The second frequency spectrum of x1 is the signal-to-noise ratio of the single first frequency spectrum;

[0011] The frequency determination module is configured to determine the frequency of the difference frequency signal according to the second frequency spectrum.

[0012] In a third aspect, an embodiment of the present application provides an OPA laser radar, comprising 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 signal enhancement method described in the first aspect above are implemented.

[0013] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the signal enhancement method described in the first aspect are implemented.

[0014] In a fifth aspect, an embodiment of the present application provides a computer program product. When the computer program product is run on an OPA laser radar, the OPA laser radar performs the steps of the signal enhancement method described in the first aspect above.

[0015] As can be seen from the above, this scheme can enhance the signal strength by obtaining the first frequency spectrum corresponding to each of the N difference frequency signals of the target detection object and performing a dot multiplication operation on the spectrum amplitudes with the same spectrum sequence number in the N first frequency spectra, and obtain a signal-to-noise ratio of Compared with the single first frequency spectrum, the signal-to-noise ratio of the second frequency spectrum is improved. times, based on the signal-to-noise ratio The second frequency spectrum can more accurately measure the frequency of the difference frequency signal, thereby improving the accuracy of the frequency measurement result of the difference frequency signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. 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 any creative work.

[0017] Figure 1 This is a schematic diagram of the implementation flow of the signal enhancement method provided in Example 1 of the present application;

[0018] Figure 2a is an example diagram of a single first frequency spectrum;

[0019] Figure 2b is an example diagram of the second frequency spectrum;

[0020] Figure 3 This is a schematic diagram of the implementation flow of the signal enhancement method provided in Example 2 of the present application;

[0021] Figure 4 This is a schematic diagram of the implementation flow of the signal enhancement method provided in Example 3 of the present application;

[0022] Figure 5 This is a schematic structural diagram of a signal enhancement device provided in Example 4 of the present application;

[0023] Figure 6 This is a schematic diagram of the structure of the OPA laser radar provided in Example 5 of the present application. DETAILED DESCRIPTION

[0024] In the following description, specific details such as specific system structures and techniques are provided for purposes of illustration rather than limitation to facilitate a thorough understanding of the embodiments of the present application. However, it will be apparent to those skilled in the art that the present application may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid obscuring the description of the present application with unnecessary detail.

[0025] It will be understood that when used in this specification and the appended claims, the term "comprising" indicates the presence of described features, integers, steps, operations, elements and / or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0026] It will also be understood that the term "and / or" used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0027] As used in this specification and the appended claims, the term "if" can be interpreted as "when" or "upon" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrase "if it is determined" or "if [described condition or event] is detected" can be interpreted as meaning "upon determination" or "in response to determining" or "upon detection of [described condition or event]" or "in response to detecting [described condition or event]," depending on the context.

[0028] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0029] References to "one embodiment" or "some embodiments" in this specification mean that a particular feature, structure, or characteristic described in conjunction with that embodiment is included in one or more embodiments of the present application. Thus, phrases such as "in one embodiment," "in some embodiments," "in other embodiments," and "in other embodiments" appearing in various places in this specification do not necessarily refer to the same embodiment, but rather mean "one or more but not all embodiments," unless otherwise specifically emphasized. The terms "including," "comprising," "having," and variations thereof all mean "including but not limited to," unless otherwise specifically emphasized.

[0030] It should be understood that the size of the serial numbers of each step in this embodiment does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of this application.

[0031] In order to illustrate the technical solution described in this application, specific embodiments are provided below.

[0032] See also Figure 1 , is a schematic diagram of the implementation flow of the signal enhancement method provided in Example 1 of the present application, which is applied to OPA laser radar. Figure 1 As shown, the signal enhancement method may include the following steps:

[0033] Step 101: Obtain a first frequency spectrum corresponding to each of N difference frequency signals of a target detection object. The first frequency spectrum includes a spectrum number and a spectrum amplitude corresponding to the spectrum number.

[0034] Wherein, N is an integer greater than 1.

[0035] The target detection object can be a static object or a moving object, such as a vehicle, pedestrian, drone, etc. This application does not limit the specific type of the target detection object.

[0036] The OPA lidar transmits a detection signal to a target object. The target object, based on the detection signal, reflects an echo signal back to the OPA lidar. After receiving the echo signal, the OPA lidar mixes it with the current local oscillator signal to generate a difference frequency signal. The detection signal can be understood as the OPA lidar's transmitted signal.

[0037] An OPA lidar includes a transmitting array, in which transmitting units emit optical signals. These signals pass through an electro-optical modulator and a beam splitter (e.g., a 1×2 beam splitter) before being split into two signals: a local oscillator (LO) signal and a detection signal. The LO signal is used for frequency mixing.

[0038] For the i-th difference frequency signal of the target detection object, where the i-th difference frequency signal is any difference frequency signal among the N difference frequency signals, a first frequency spectrum corresponding to the i-th difference frequency signal can be obtained by performing a fast Fourier transform on the i-th difference frequency signal. The present application does not limit the specific number of frequency domain sampling points for the fast Fourier transform, but requires that the number of frequency domain sampling points for the N difference frequency signals when performing the fast Fourier transform be the same to facilitate calculation of the point-wise accumulation of the frequency spectrum in step 102.

[0039] The spectrum number is related to the length of the Fourier transform spectrum analysis. Each spectrum number corresponds to a spectrum amplitude. For example, if the spectrum analysis length is 4096, the spectrum number ranges from 0 to 4095. The frequency spectrum includes 4096 spectrum numbers and the spectrum amplitudes corresponding to each of these 4096 spectrum numbers.

[0040] Step 102: Perform a dot multiplication operation on the spectrum amplitudes with the same spectrum sequence number in the N first frequency spectra to obtain a signal-to-noise ratio of The second frequency spectrum of x1 is the signal-to-noise ratio of the single first frequency spectrum.

[0041] By performing a dot multiplication operation on the spectrum amplitudes with the same spectrum sequence number in the N first frequency spectra, the dot multiplication accumulation of the N first frequency spectra can be achieved, thereby enhancing the signal strength and obtaining an improved signal-to-noise ratio. times the second frequency spectrum.

[0042] like Figure 2a Shown is an example diagram of a single first frequency spectrum; Figure 2b The following is an example of the second frequency spectrum. Figure 2a , Figure 2b The signal strength of the second frequency spectrum is enhanced and the noise strength is reduced, thereby improving the signal-to-noise ratio. The spectrum amplitude in the frequency spectrum corresponds to the signal strength.

[0043] In one embodiment, the spectrum amplitudes with the same spectrum number in the N first frequency spectra are multiplied by a dot product operation to obtain a signal-to-noise ratio of The second frequency spectrum includes:

[0044] Performing a dot product operation on the amplitudes of the N first frequency spectra with the same frequency spectrum sequence number to obtain the signal power of the second frequency spectrum;

[0045] determining the noise power of the second frequency spectrum based on the single noise power;

[0046] Calculating a signal-to-noise ratio of the second frequency spectrum according to the signal power of the second frequency spectrum and the noise power of the second frequency spectrum;

[0047] in, x N is the signal-to-noise ratio of the second frequency spectrum, A2N is the signal power of the second frequency spectrum, A is the amplitude of the echo signal, is the noise power of the second frequency spectrum, σ 2 is the single noise power.

[0048] The OPA laser radar can achieve the point product accumulation of N first frequency spectra by performing a dot multiplication operation on the spectrum amplitudes with the same spectrum sequence number in N first frequency spectra to obtain a second frequency spectrum. According to the signal power of the second frequency spectrum and the noise power of the second frequency spectrum, the signal-to-noise ratio of the second frequency spectrum can be calculated.

[0049] Assume that the echo signal is a complex signal contaminated by additive noise The power of the noise (i.e. the power of a single noise) is σ 2 , then the signal-to-noise ratio of a single first frequency spectrum is The signal-to-noise ratio of a single first frequency spectrum may be understood as the signal-to-noise ratio of a single echo signal. represents the phase of the echo signal, e represents the natural exponent, and j represents the imaginary unit.

[0050] Since one difference frequency signal corresponds to one echo signal, then N difference frequency signals correspond to N echo signals. Since the noise parts of the N echo signals are independent of each other, the noise power of the second frequency spectrum is the accumulation of the individual noise powers.

[0051] Step 103: Determine the frequency of the difference frequency signal according to the second frequency spectrum.

[0052] Improved signal-to-noise ratio The second frequency spectrum can more accurately measure the frequency of the difference frequency signal, thereby improving the accuracy of the frequency measurement result of the difference frequency signal.

[0053] Improved signal-to-noise ratio The frequency of the difference frequency signal obtained by measuring the second frequency spectrum can more accurately obtain the distance between the target detection object and the OPA lidar, thereby improving the ranging capability of the OPA lidar.

[0054] Table 1 shows the distance measured based on a single first frequency spectrum and the distance measured based on the dot product accumulation of three first frequency spectra.

[0055]

[0056] Table 1 uses three distance measurements as an example. As can be seen from Table 1, the distance measured based on the dot product accumulation of the three first frequency spectra is closer to the actual distance, indicating that this embodiment can improve the ranging capability of the OPA lidar and obtain a more accurate distance.

[0057] In one embodiment, determining the frequency of the difference frequency signal according to the second frequency spectrum includes:

[0058] Comparing the spectrum amplitudes corresponding to the spectrum numbers in the second frequency spectrum to obtain a second maximum value, where the second maximum value refers to the maximum value among the spectrum amplitudes corresponding to the spectrum numbers in the second frequency spectrum;

[0059] The frequency of the difference frequency signal is determined according to the frequency spectrum sequence number corresponding to the second maximum value.

[0060] The second maximum value is the peak value of the second frequency spectrum.

[0061] According to the spectrum number corresponding to the second maximum value, the sampling frequency of the fast Fourier transform and the spectrum analysis length, the frequency of the difference frequency signal can be calculated as follows: (sampling frequency*spectrum number) / spectrum analysis length.

[0062] The embodiment of the present application obtains the first frequency spectra corresponding to the N difference frequency signals of the target detection object, and performs a dot multiplication operation on the spectrum amplitudes with the same spectrum sequence number in the N first frequency spectra, so as to enhance the signal strength and obtain a signal-to-noise ratio of Compared with the single first frequency spectrum, the signal-to-noise ratio of the second frequency spectrum is improved. times, based on the signal-to-noise ratio The second frequency spectrum can more accurately measure the frequency of the difference frequency signal, thereby improving the accuracy of the frequency measurement result of the difference frequency signal.

[0063] See also Figure 3 , is a schematic diagram of the implementation flow of the signal enhancement method provided in Example 2 of this application, which is applied to an OPA laser radar. The OPA laser radar includes N groups of antenna arrays, where N is an integer greater than 1. Figure 3 As shown, the signal enhancement method may include the following steps:

[0064] Step 301: transmit a detection signal to a target detection object. The detection signal is used to indicate that the target detection object reflects an echo signal.

[0065] The target detection object can be a static object or a moving object, such as a vehicle, pedestrian, drone, etc. This application does not limit the specific type of the target detection object.

[0066] The OPA lidar includes a transmitting array, in which the transmitting units emit optical signals. After passing through an electro-optical modulator and a 1×2 beam splitter, the optical signals are split into two signals: a local oscillator signal and a detection signal. The local oscillator signal is used for frequency mixing.

[0067] Step 302: Acquire echo signals received by N groups of antenna arrays at the same time to obtain N echo signals.

[0068] The OPA lidar includes multiple antenna arrays for receiving signals. The N antenna arrays can be all or part of the OPA lidar's antenna arrays, without limitation.

[0069] The OPA lidar can transmit a detection signal to a target object. The target object, based on the detection signal, reflects an echo signal back to the OPA lidar. The OPA lidar can simultaneously receive these echo signals through N antenna arrays, generating N echo signals. Each antenna array corresponds to one echo signal, so N antenna arrays correspond to N echo signals.

[0070] This embodiment is based on the multi-antenna array structure of the OPA laser radar. By transmitting and receiving multiple signals at once (that is, transmitting a detection signal once and receiving N echo signals at the same time), N echo signals can be quickly obtained without affecting the scanning frequency of the OPA laser radar.

[0071] Step 303: Mix the N echo signals with the current local oscillator signal to obtain difference frequency signals corresponding to the N echo signals.

[0072] For the jth echo signal, the jth echo signal is any echo signal among the N echo signals. By mixing the jth echo signal with the current local oscillator signal, a difference frequency signal corresponding to the jth echo signal can be obtained.

[0073] Step 304: Perform fast Fourier transform on the N difference frequency signals to obtain first frequency spectra corresponding to the N difference frequency signals.

[0074] For the i-th difference frequency signal, the i-th difference frequency signal is any difference frequency signal among the N difference frequency signals. By performing fast Fourier transform on the i-th difference frequency signal, a first frequency spectrum corresponding to the i-th difference frequency signal can be obtained.

[0075] Step 305: Perform a dot multiplication operation on the spectrum amplitudes with the same spectrum sequence number in the N first frequency spectra to obtain a signal-to-noise ratio of The second frequency spectrum of x1 is the signal-to-noise ratio of the single first frequency spectrum.

[0076] This step is the same as step 102. For details, please refer to the relevant description of step 102, which will not be repeated here.

[0077] Step 306: Determine the frequency of the difference frequency signal according to the second frequency spectrum.

[0078] This step is the same as step 103. For details, please refer to the relevant description of step 103, which will not be repeated here.

[0079] Based on the first embodiment, this embodiment is based on the multi-antenna array structure of the OPA laser radar, and can quickly obtain N echo signals without affecting the scanning frequency of the OPA laser radar.

[0080] See also Figure 4 , is a schematic diagram of the implementation flow of the signal enhancement method provided in Example 3 of this application, which is applied to OPA laser radar. Figure 4 As shown, the signal enhancement method may include the following steps:

[0081] Step 401: transmit a detection signal to a target detection object. The detection signal is used to indicate that the target detection object reflects an echo signal.

[0082] The target detection object can be a static object or a moving object, such as a vehicle, pedestrian, drone, etc. This application does not limit the specific type of the target detection object.

[0083] The OPA lidar includes a transmitting array, in which the transmitting units emit optical signals. After passing through an electro-optical modulator and a 1×2 beam splitter, the optical signals are split into two signals: a local oscillator signal and a detection signal. The local oscillator signal is used for frequency mixing.

[0084] The OPA lidar can transmit a detection signal to the target object, and the target object can reflect an echo signal to the OPA lidar based on the detection signal.

[0085] Step 402: Acquire a single echo signal.

[0086] The OPA lidar includes multiple antenna arrays, which are used to receive signals.

[0087] In this embodiment, the OPA laser radar can receive the echo signal through a group of antenna arrays to obtain a single echo signal.

[0088] Step 403: Mix the echo signal with the current local oscillator signal to obtain a difference frequency signal corresponding to the echo signal.

[0089] Step 404: Perform a fast Fourier transform on the difference frequency signal to obtain a first frequency spectrum corresponding to the difference frequency signal.

[0090] Step 405: Determine whether the spectrum amplitude of the first frequency spectrum is less than an amplitude threshold.

[0091] By judging whether the spectrum amplitude of the first frequency spectrum is less than the amplitude threshold, the strength of the echo signal can be judged; if the spectrum amplitude of the first frequency spectrum is less than the amplitude threshold, the intensity of the echo signal is judged to be weak, and it is necessary to perform signal enhancement through the scheme of the present application to improve the ranging capability of the OPA lidar; if the spectrum amplitude of the first frequency spectrum is greater than or equal to the amplitude threshold, the intensity of the echo signal is judged to be strong, and the distance can be measured more accurately based on the echo signal with stronger intensity, without the need to execute the scheme of the present application. Among them, the amplitude threshold can be obtained by actual testing. In some embodiments, reasons such as long ranging and weak reflecting surface may cause the echo signal to have a weak intensity.

[0092] When the spectrum amplitude of the first frequency spectrum is less than the amplitude threshold, N first frequency spectra can be obtained by returning to execute step 401 to step 404 N-1 times.

[0093] In this embodiment, when the intensity of the echo signal is weak, the multi-antenna array structure based on the OPA laser radar can obtain a single first frequency spectrum through a one-transmit-one-receive method (i.e., transmitting a detection signal once and receiving a single echo signal). By repeating the one-transmit-one-receive method N times, N first frequency spectra can be obtained.

[0094] Repeating the transmission and reception N times requires transmitting N detection signals to the target object. In order to reduce the measurement errors of frequency and distance, the detection point on the target object targeted by the N detection signals needs to remain unchanged. That is, when the OPA lidar transmits N detection signals, the point on the target object detected (i.e., the detection point) is the same.

[0095] Optionally, before determining whether the spectrum amplitude of the first frequency spectrum is less than an amplitude threshold, this embodiment further includes:

[0096] Comparing spectrum amplitudes corresponding to the spectrum numbers in the first frequency spectrum to obtain a first maximum value, where the first maximum value refers to the maximum value among the spectrum amplitudes corresponding to the spectrum numbers in the first frequency spectrum;

[0097] A first maximum value is determined as a spectral amplitude of the first frequency spectrum.

[0098] The first maximum value is the peak value of the first frequency spectrum. The signal strength corresponding to the peak value of the first frequency spectrum is the strongest. If the spectrum amplitude of the first frequency spectrum is less than the amplitude threshold, it means that the spectrum amplitudes corresponding to all spectrum numbers in the first spectrum are less than the amplitude threshold, indicating that the echo signal strength is weak.

[0099] Step 406: When N first frequency spectra are obtained, the spectrum amplitudes with the same spectrum number in the N first frequency spectra are multiplied to obtain a signal-to-noise ratio of The second frequency spectrum of x1 is the signal-to-noise ratio of the single first frequency spectrum.

[0100] This step is partially identical to step 102 . For details of the identical parts, please refer to the relevant description of step 102 and will not be repeated here.

[0101] Step 407: Determine the frequency of the difference frequency signal according to the second frequency spectrum.

[0102] This step is the same as step 103. For details, please refer to the relevant description of step 103, which will not be repeated here.

[0103] Based on the first embodiment, this embodiment, based on the multiple antenna array structures of the OPA lidar, can obtain N first frequency spectra by repeating N times of one transmission and one reception when the echo signal strength is weak. In addition, because the echo signal strength is weak, the signal-to-noise ratio of the echo signal is low. Under low signal-to-noise ratio conditions, this embodiment enables the OPA lidar to more accurately measure the frequency of the difference frequency signal, thereby improving the ranging capability of the OPA lidar.

[0104] Corresponding to the signal enhancement method of the above embodiment, Figure 5 The structure block diagram of the signal enhancement device provided in the fourth embodiment of the present application is shown. The signal enhancement device can be applied to the OPA laser radar. For ease of explanation, only the part related to the embodiment of the present application is shown.

[0105] The signal enhancement device includes:

[0106] The frequency spectrum acquisition module 51 is used to obtain a first frequency spectrum corresponding to each of the N difference frequency signals of the target detection object, wherein the first frequency spectrum includes a spectrum number and a spectrum amplitude corresponding to the spectrum number, where N is an integer greater than 1;

[0107] The dot product operation module 52 is used to perform dot product operation on the spectrum amplitudes with the same spectrum sequence number in the N first frequency spectra to obtain a signal-to-noise ratio of The second frequency spectrum of x1 is the signal-to-noise ratio of the single first frequency spectrum;

[0108] The frequency determination module 53 is configured to determine the frequency of the difference frequency signal according to the second frequency spectrum.

[0109] Optionally, the OPA laser radar includes N groups of antenna arrays, and the frequency spectrum acquisition module 51 is specifically used to:

[0110] A detection signal is transmitted to the target detection object, and the detection signal is used to indicate that the target detection object reflects an echo signal;

[0111] Acquire the echo signals received by N groups of antenna arrays at the same time to obtain N echo signals;

[0112] Mix the N echo signals with the current local oscillator signal respectively to obtain the difference frequency signals corresponding to the N echo signals;

[0113] Fast Fourier transform is performed on the N difference frequency signals respectively to obtain first frequency spectra corresponding to the N difference frequency signals.

[0114] Optionally, the frequency spectrum acquisition module 51 is specifically configured to:

[0115] A detection signal is transmitted to the target detection object, and the detection signal is used to indicate that the target detection object reflects an echo signal;

[0116] Acquire a single echo signal;

[0117] Mix the echo signal with the current local oscillator signal to obtain the difference frequency signal corresponding to the echo signal;

[0118] Performing a fast Fourier transform on the difference frequency signal to obtain a first frequency spectrum corresponding to the difference frequency signal;

[0119] Determining whether the spectrum amplitude of the first frequency spectrum is less than an amplitude threshold;

[0120] If the spectrum amplitude of the first frequency spectrum is less than the amplitude threshold, the process returns to executing the steps of transmitting a detection signal to the target detection object, obtaining a single echo signal, mixing the echo signal with the current local oscillator signal to obtain a difference frequency signal, and performing a fast Fourier transform on the difference frequency signal to obtain the first frequency spectrum corresponding to the difference frequency signal, until N first frequency spectra are obtained.

[0121] Optionally, the detection point on the target detection object targeted by the N detection signals remains unchanged.

[0122] Optionally, the frequency spectrum acquisition module 51 is further configured to:

[0123] Comparing the spectrum amplitudes corresponding to the spectrum serial numbers in the first frequency spectrum to obtain a first maximum value, where the first maximum value refers to the maximum value among the spectrum amplitudes corresponding to the spectrum serial numbers in the first frequency spectrum;

[0124] A first maximum value is determined as a spectral amplitude of the first frequency spectrum.

[0125] Optionally, the difference frequency signal is determined by an echo signal reflected by the target detection object, and the dot product operation module 52 is specifically used to:

[0126] Performing a dot product operation on the amplitudes of the N first frequency spectra with the same frequency spectrum sequence number to obtain the signal power of the second frequency spectrum;

[0127] determining the noise power of the second frequency spectrum based on the single noise power;

[0128] Calculating a signal-to-noise ratio of the second frequency spectrum according to the signal power of the second frequency spectrum and the noise power of the second frequency spectrum;

[0129] in, x N is the signal-to-noise ratio of the second frequency spectrum, A 2N is the signal power of the second frequency spectrum, A is the amplitude of the echo signal, is the noise power of the second frequency spectrum, σ 2 is the single noise power.

[0130] Optionally, the frequency determination module 53 is specifically configured to:

[0131] Comparing the spectrum amplitudes corresponding to the spectrum numbers in the second frequency spectrum to obtain a second maximum value, where the second maximum value refers to the maximum value among the spectrum amplitudes corresponding to the spectrum numbers in the second frequency spectrum;

[0132] The frequency of the difference frequency signal is determined according to the frequency spectrum sequence number corresponding to the second maximum value.

[0133] It should be noted that the information interaction, execution process, etc. between the above-mentioned devices / units are based on the same concept as the method embodiment of this application. Their specific functions and technical effects can be found in the method embodiment section and will not be repeated here.

[0134] Figure 6 This is a schematic diagram of the structure of the OPA laser radar provided in Example 5 of this application. Figure 6 As shown, the OPA laser radar 6 of this embodiment includes: one or more processors 60 (only one is shown in the figure), a memory 61, and a computer program 62 stored in the memory 61 and executable on the processor 60. When the processor 60 executes the computer program 62, the steps of the above-mentioned various signal enhancement method embodiments are implemented.

[0135] The OPA laser radar may include, but is not limited to, a processor 60 and a memory 61. Those skilled in the art will understand that Figure 6 The OPA laser radar 6 is merely an example and does not limit the OPA laser radar 6. The OPA laser radar 6 may include more or fewer components than shown in the figure, or may combine certain components, or different components. For example, the OPA laser radar may also include input and output devices, network access devices, buses, etc. Optionally, the OPA laser radar may also include an antenna array, a transmitting array, an electro-optical modulator, a beam splitter, etc.

[0136] The processor 60 may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), 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.

[0137] The memory 61 can be an internal storage unit of the OPA laser radar 6, such as a hard disk or memory of the OPA laser radar 6. The memory 61 can also be an external storage device of the OPA laser radar 6, such as a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (SecureDigital, SD) card, a flash card (Flash Card), etc. equipped on the OPA laser radar 6. Furthermore, the memory 61 can also include both the internal storage unit of the OPA laser radar 6 and an external storage device. The memory 61 is used to store the computer program and other programs and data required by the OPA laser radar. The memory 61 can also be used to temporarily store data that has been output or is to be output.

[0138] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated into one processing unit, or each unit can exist physically alone, 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 and modules 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 and modules in the above-mentioned device can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0139] An embodiment of the present application further provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments can be implemented.

[0140] An embodiment of the present application also provides a computer program product, which, when run on an OPA laser radar, enables the OPA laser radar to implement the steps in the above-mentioned method embodiments when executed.

[0141] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0142] Those skilled 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 beyond the scope of this application.

[0143] In the embodiments provided in this application, it should be understood that the disclosed device / OPA laser radar and method can be implemented in other ways. For example, the device / OPA laser radar embodiments described above are merely schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0144] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0145] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present application implements all or part of the process in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and when the computer program is executed by the processor, it can implement the steps of the above-mentioned various method embodiments. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electric carrier signals and telecommunication signals.

[0146] The above-described embodiments 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, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present application, and should all be included in the scope of protection of the present application.

Claims

1. A signal enhancement method, characterized in that: Applied to OPA laser radar, the signal enhancement method includes: Obtaining a first frequency spectrum corresponding to each of N difference frequency signals of the target detection object, wherein the first frequency spectrum includes a spectrum number and a spectrum amplitude corresponding to the spectrum number, where N is an integer greater than 1; Perform a dot multiplication operation on the spectrum amplitudes of the N first frequency spectra with the same spectrum number, and obtain the signal-to-noise ratio: The second frequency spectrum of x1 is the signal-to-noise ratio of the single first frequency spectrum; The frequency of the difference frequency signal is determined according to the second frequency spectrum.

2. The signal enhancement method according to claim 1, wherein: The OPA laser radar includes N groups of antenna arrays, and obtaining first frequency spectra corresponding to N difference frequency signals of the target detection object includes: transmitting a detection signal to the target detection object, wherein the detection signal is used to indicate that the target detection object reflects an echo signal; Acquire the echo signals received by N groups of the antenna arrays at the same time to obtain N echo signals; Mixing the N echo signals with the current local oscillator signal respectively to obtain difference frequency signals corresponding to the N echo signals; Perform fast Fourier transform on the N difference frequency signals respectively to obtain first frequency spectra corresponding to the N difference frequency signals.

3. The signal enhancement method according to claim 1, wherein: The acquiring of the first frequency spectrum corresponding to each of the N difference frequency signals of the target detection object comprises: transmitting a detection signal to the target detection object, wherein the detection signal is used to indicate that the target detection object reflects an echo signal; Acquiring a single echo signal; Mixing the echo signal with the current local oscillator signal to obtain a difference frequency signal corresponding to the echo signal; Performing a fast Fourier transform on the difference frequency signal to obtain a first frequency spectrum corresponding to the difference frequency signal; Determining whether the spectrum amplitude of the first frequency spectrum is less than an amplitude threshold; If the spectrum amplitude of the first frequency spectrum is less than the amplitude threshold, return to execute the steps of transmitting a detection signal to the target detection object once, obtaining a single echo signal, mixing the echo signal with the current local oscillator signal to obtain a difference frequency signal, and performing a fast Fourier transform on the difference frequency signal to obtain the first frequency spectrum corresponding to the difference frequency signal, until N first frequency spectra are obtained.

4. The signal enhancement method according to claim 3, wherein: The detection point on the target detection object targeted by the detection signals N times remains unchanged.

5. The signal enhancement method according to claim 3, wherein: Before determining whether the spectrum amplitude of the first frequency spectrum is less than an amplitude threshold, the method further includes: Comparing spectrum amplitudes corresponding to the spectrum numbers in the first frequency spectrum to obtain a first maximum value, where the first maximum value refers to the maximum value among the spectrum amplitudes corresponding to the spectrum numbers in the first frequency spectrum; A first maximum value is determined as the spectrum amplitude of the first frequency spectrum.

6. The signal enhancement method according to any one of claims 1 to 5, characterized in that: The difference frequency signal is determined by the echo signal reflected by the target detection object, and the spectrum amplitudes with the same spectrum number in the N first frequency spectra are multiplied to obtain a signal-to-noise ratio of The second frequency spectrum includes: Performing a dot product operation on the amplitudes of the N spectrums with the same spectrum sequence number in the first frequency spectrum to obtain the signal power of the second frequency spectrum; determining the noise power of the second frequency spectrum according to the single noise power; calculating a signal-to-noise ratio of the second frequency spectrum according to the signal power of the second frequency spectrum and the noise power of the second frequency spectrum; in, x N is the signal-to-noise ratio of the second frequency spectrum, A 2N is the signal power of the second frequency spectrum, A is the amplitude of the echo signal, is the noise power of the second frequency spectrum, σ 2 is the single noise power.

7. The signal enhancement method according to any one of claims 1 to 5, characterized in that: Determining the frequency of the difference frequency signal according to the second frequency spectrum includes: Comparing spectrum amplitudes corresponding to the spectrum numbers in the second frequency spectrum to obtain a second maximum value, where the second maximum value refers to the maximum value among the spectrum amplitudes corresponding to the spectrum numbers in the second frequency spectrum; The frequency of the difference frequency signal is determined according to the frequency spectrum sequence number corresponding to the second maximum value.

8. A signal enhancement device, characterized in that: Applied to OPA laser radar, the signal enhancement device includes: A frequency spectrum acquisition module is configured to acquire a first frequency spectrum corresponding to each of N difference frequency signals of the target detection object, wherein the first frequency spectrum includes a spectrum number and a spectrum amplitude corresponding to the spectrum number, where N is an integer greater than 1; The dot multiplication operation module is used to perform dot multiplication operation on the spectrum amplitudes with the same spectrum sequence number in the N first frequency spectra to obtain a signal-to-noise ratio of The second frequency spectrum of x1 is the signal-to-noise ratio of the single first frequency spectrum; The frequency determination module is configured to determine the frequency of the difference frequency signal according to the second frequency spectrum.

9. An OPA laser radar, 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 signal enhancement method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the signal enhancement method according to any one of claims 1 to 7 are implemented.

Images