Pulse laser coherent ranging method and device based on linear frequency modulation local oscillator

Abstract

The present invention discloses a pulse laser coherent ranging method and device based on linear frequency modulation local oscillator, comprising: when a first linear modulator is triggered, a linear frequency modulation signal of a preset frequency interval is generated; based on the generated linear frequency modulation signal, a target signal is linearly frequency modulated to form a first signal; the signal light is modulated; the modulated signal light is combined with the first signal; after the combined light signal passes through a detector, the acquired echo signal is sampled and matched filtered; and the distance is resolved according to the result of the matched filtering. The embodiment of the present application adopts different linear modulation modes for the local oscillator light and the output light, respectively, and uses the principle of coherent detection to match filter the linear modulation waveform after the echo difference frequency, thereby solving the problems of multiple blind points and distance ambiguity in high repetition rate integrated pulse laser ranging.

Description

Technical Field

[0001] The present invention relates to the technical field of laser ranging, and in particular to a pulse laser coherent ranging method and device based on linear frequency modulation local oscillator. Background Art

[0002] When detecting long-distance stationary targets, the traditional integrated transceiver high-repetition-rate pulsed laser coherent ranging splits the laser emitted by the seed source into one beam as the local oscillator light and the other as the signal light. The signal light is subjected to acousto-optic frequency modulation and chopped to form a pulse signal light with frequency shift information. The pulse signal light is then emitted from the lens through a circulator and an optical amplifier. The received signal light and the local oscillator difference frequency are used to detect the time information of the difference frequency and calculate the target distance.

[0003] High-repetition-rate pulse laser coherent ranging has a high repetition frequency, so when the target is far away, it will cause distance ambiguity. That is, within a trigger cycle, due to the long distance of the target, the pulse cannot return to the receiving end within this trigger cycle, and needs to arrive in other cycles, causing ambiguity in the distance solution; at the same time, for the integrated transceiver laser pulse coherent detection, since the lens end face will reflect strong outgoing light at the moment of emission, it is impossible to collect echo light at close range within the emission pulse cycle, that is, the echo light is submerged in the lens reflected light, resulting in the inability to detect close-range targets within the pulse cycle and targets corresponding to the entire pulse cycle.

[0004] To solve the above problems, the existing technology adopts the method of using multiple frequencies for fuzzy resolution and using the detector to shut down at the pulse emission moment. The problem brought by this is that the resolution is relatively complicated and there are multiple blind spots. Summary of the invention

[0005] The embodiment of the present invention provides a pulse laser coherent ranging method and device based on linear frequency modulated local oscillator, which adopts different linear modulation modes for local oscillator light and output light respectively, and utilizes the principle of coherent detection. After the combined light signal passes through a band-stop or low-pass detector and an acquisition system, matched filtering is performed on the linear modulation waveform after the echo difference frequency, so as to solve the problems of multiple blind points and distance ambiguity in high repetition rate integrated pulse laser ranging.

[0006] The embodiment of the present invention provides a pulse laser coherent ranging method based on linear frequency modulation local oscillator, comprising:

[0007] When the first linear modulator is triggered, a linear frequency modulation signal of a preset frequency interval is generated;

[0008] Performing linear frequency modulation on the target signal based on the generated linear frequency modulation signal, so that the light frequency emitted by the seed source is loaded with the linear frequency modulation signal on the base frequency to form a first signal;

[0009] Modulating the signal light, wherein the modulation frequency of the frequency modulated pulse emitted after the modulation is determined by the slope of the linear frequency modulated signal and the pulse period;

[0010] Combining the modulated signal light with the first signal;

[0011] After the combined optical signal passes through the detector, the acquired echo signal is sampled and matched filtered;

[0012] The distance is calculated based on the results of matched filtering.

[0013] Optionally, when the first linear modulator is triggered, generating a linear frequency modulation signal in a preset frequency interval includes:

[0014] When the first linear modulator is triggered, the frequency generated is arrive The trigger period is 0 to Trig local Linear frequency modulation signal The slope of the linear frequency modulation signal is Among them, Trig local The maximum detectable distance is determined based on the laser coherence ranging system.

[0015] Optionally, the modulation frequency of the nth pulse of the frequency-modulated pulse emitted after modulating the signal light satisfies:

[0016]

[0017] Among them, Trig sig represents the repetition period, k1 represents the frequency modulation slope of the transmitted signal, t n It means that within a cycle, with the trigger time as time 0, the time position of each transmitted signal satisfies:

[0018] (n-1)×Trig sig <t n <(n-1)×Trig sig +T sig

[0019] T sig represents the pulse width, It is expressed as the end frequency of the first linear frequency modulation pulse based on the optical frequency in the transmitted signal light. It indicates the starting frequency of the first linear frequency modulation pulse based on the optical frequency in the transmitted signal light.

[0020] Optionally, performing matched filtering on the acquired echo signal includes:

[0021] According to the trigger signal for modulating the signal light, data acquisition and matched filtering processing are performed in each repetition period. The matched filtering processing adopts the following steps:

[0022] Determine the frequency range of the difference frequency characteristic between the local oscillator light and the echo signal:

[0023] Based on the frequency range, fit the frequency of the difference frequency characteristic, satisfying:

[0024] f match (r) = (k1 - k0)×r + f match_low

[0025] where r is the fitting time, satisfying:

[0026]

[0027] f match_high represents the termination frequency of the designed matching frequency range, and f match_low represents the starting frequency of the designed matching frequency range;

[0028] Determine the matched filter based on the fitted frequency of the difference frequency characteristic.

[0029] Optionally, after obtaining the matched filtering results of each repetition period, accumulate the matched filtering results to maximize the matched result value.

[0030] Optionally, distance calculation based on the result of matched filtering includes:

[0031] In the case of only one matched result, the distance of the target to be measured satisfies:

[0032]

[0033] where f s represents the sampling rate, N0 represents the abscissa reference of the matched result, N1 represents the abscissa value where the actual matched result is located, and c represents the speed of light;

[0034] In the case of having two matched results (N1, N2), the corresponding abscissa values are N1 and N2 respectively, and N1 < N0 < N2. If the amplitude corresponding to N2 is greater than the amplitude corresponding to N1, the distance of the target to be measured satisfies:

[0035]

[0036] If the amplitude corresponding to N1 is greater than the amplitude corresponding to N2, the distance of the target to be measured satisfies:

[0037]

[0038] An embodiment of the present application further provides a laser coherent ranging device, comprising a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the steps of the aforementioned laser coherent ranging method are implemented.

[0039] The embodiment of the present application further proposes a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the aforementioned laser coherent ranging method are implemented.

[0040] The embodiment of the present application adopts different linear modulation methods for the local oscillation light and the output light respectively, and utilizes the principle of coherent detection to perform matched filtering processing on the linear modulation waveform after the echo difference frequency, so as to solve the problems of multiple blind points and distance ambiguity in high repetition rate integrated pulse laser ranging.

[0041] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0043] Figure 1 This is a basic flow chart of the pulsed laser coherent ranging method according to an embodiment of the present application;

[0044] Figure 2 This is an implementation case of the high repetition rate transceiver integrated pulse laser coherent ranging system based on linear frequency modulation in the embodiment of the present application;

[0045] Figure 3 This is another implementation case of the high repetition rate transceiver integrated pulse laser coherent ranging system based on linear frequency modulation in the embodiment of the present application;

[0046] Figure 4 This is another implementation case of the high repetition rate transceiver integrated pulse laser coherent ranging system based on linear frequency modulation in the embodiment of the present application;

[0047] Figure 5 This is an example of the signal trigger timing of the embodiment of the present application;

[0048] Figure 6 This is a time-frequency diagram of the laser seed source after being modulated by the modulator 1 in the embodiment of the present application;

[0049] Figure 7 This is a time-frequency diagram of the laser seed source after being modulated by the modulator 2 in the embodiment of the present application;

[0050] Figure 8 This is a schematic diagram of the difference frequency results of N pulses in the embodiment of the present application (τ′ <Trig sig );

[0051] Fig. 9 Schematic diagram of the result of N pulse difference frequencies in the embodiment of the present application (T sig <τ′ <Trig sig );

[0052] Fig.10 This is an example of a matched filter design according to an embodiment of the present application;

[0053] Fig.11 The N pulse difference frequency matching filtering result diagram (τ′) of the embodiment of the present application is shown in FIG. <Trig sig );

[0054] Fig.12 This is a graph showing the result of N pulse frequency matching filters in the embodiment of the present application (T sig <τ′ <Trig sig ). DETAILED DESCRIPTION

[0055] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0056] The embodiment of the present invention provides a pulse laser coherent ranging method based on linear frequency modulation local oscillator, such as Figure 1 As shown, the following steps are included:

[0057] In step S101 , when a first linear modulator is triggered, a linear frequency modulation signal of a preset frequency interval is generated.

[0058] In the present application, various laser coherent ranging systems can be used to form the local oscillation light. For example, Figure 2 As shown, linear modulator 1 and linear modulator 2 receive Figure 2After the trigger signal shown, the frequency modulation operation is performed respectively. After the laser seed source is linearly modulated 1, it enters the beam splitter, one beam is used as the local oscillator light, and the other beam is used as the signal light. After the signal light passes through the optical modulator controlled by the linear modulator 2, it passes through the circulator and the amplifier, and the high-power pulse laser is emitted from the lens. The echo signal passes through the circulator 3 end and the optical amplifier and enters the beam combiner, and is combined with the local oscillator light. After passing through the detector, data operations such as sampling and matched filtering are performed to obtain the fixed target distance.

[0059] As another example, Figure 3 As shown, linear modulator 1 and linear modulator 2 receive Figure 2 After the trigger signal shown, the frequency modulation operation is performed respectively. The laser seed source enters the beam splitter, one beam is used as the local oscillator light, and the other beam is used as the signal light. The local oscillator light passes through the optical modulator 1 controlled by the linear modulator 1, and the signal light passes through the optical modulator 2 controlled by the linear modulator 2. The signal light passes through the circulator and the amplifier, and the high-power pulse laser is emitted from the lens. The echo signal passes through the circulator 3 end and the optical amplifier and enters the beam combiner, and is combined with the local oscillator light. After passing through the detector, data operations such as sampling and matched filtering are performed to obtain the fixed target distance.

[0060] As another example, Figure 4 As shown, the laser seed source generates a linear Chirp signal with a repetitive period after internal modulation, and generates a trigger electrical signal at the same time. The electrical signal triggers the linear modulator 2 to generate a trigger signal 2. After the linearly modulated optical signal enters the beam splitter, one beam is used as the local oscillator light and the other beam is used as the signal light. The signal light then passes through the optical modulator controlled by the linear modulator 2, and then through the circulator and amplifier to emit the high-power pulse laser from the lens. The echo signal enters the beam combiner after passing through the circulator 3 and the optical amplifier, and is combined with the local oscillator light. After passing through the detector, data operations such as sampling and matched filtering are performed to obtain a fixed target distance.

[0061] In step S102, the target signal is subjected to linear frequency modulation based on the generated linear frequency modulation signal, so that the light frequency emitted by the seed source is loaded with the linear frequency modulation signal on the base frequency to form a first signal. The target signal referred to in this example can be the local oscillator light signal after passing through the beam splitter, or the laser signal of the laser seed source. After the linear frequency modulation, the light frequency emitted by the seed source is loaded with the linear tuning frequency on the base frequency to form a first signal. arrive

[0062] In step S103, the signal light is modulated, and the modulation frequency of the frequency modulated pulse emitted after modulation is determined by the slope and pulse period of the linear frequency modulated signal. The signal light referred to in this example is another signal relative to the local oscillator light.

[0063] In step S104, the modulated signal light is combined with the first signal.

[0064] In step S105, after the combined optical signal passes through the detector, the acquired echo signal is sampled and matched filtered. The detector referred to in this example can be a band-stop or low-pass detector. By selecting a detector with an appropriate frequency response, the problem of multiple blind spots caused by the need to shut down the detector response when the lens echo light is too strong at the time of emission can be solved.

[0065] In step S106, distance calculation is performed according to the result of matched filtering.

[0066] The embodiment of the present invention adopts different linear modulation modes for the local oscillator light and the output light respectively, and utilizes the principle of coherent detection. After the combined light signal passes through a band-stop or low-pass detector and an acquisition system, matched filtering is performed on the linear modulation waveform after the echo difference frequency, so as to solve the problems of multiple blind points and distance ambiguity in high-repetition-rate integrated pulse laser ranging.

[0067] In some embodiments, when the first linear modulator is triggered, generating a linear frequency modulation signal of a preset frequency interval includes:

[0068] When the first linear modulator is triggered, the frequency generated is arrive The trigger period is 0 to Trig local Linear frequency modulation signal The slope of the linear frequency modulation signal is Among them, Trig local The maximum detectable distance is determined based on the laser coherence ranging system.

[0069] Specifically, in this example, the signal modulation process is further described. Assume that the maximum detectable distance of the laser coherent ranging system is L max , L max satisfy:

[0070]

[0071] like Figure 5 As shown, when the linear modulator 1 receives a trigger signal, the frequency generated changes from arrive Time from 0 to Trig local A linear frequency modulation signal, such as Figure 6 As shown, assuming (The above frequency modulation scheme of this application is taken as an example, and the lower frequency modulation scheme is also applicable to the method of this application in principle). 0 <t<Trig local

[0072]

[0073] for Figure 2 The laser coherent ranging system shown in the figure can use a linear modulator 1 to perform linear frequency modulation on a laser seed source, so that the light frequency emitted by the seed source is loaded with a linear tuning frequency on the base frequency. arrive After passing through the beam splitter, one beam of light is used as the local oscillator, and the other beam of light is used as the signal light and passes through the optical modulator controlled by the linear modulation 2 and is modulated again.

[0074] for Figure 3 The laser coherent ranging system is shown in FIG. The laser seed source is first split into two beams by a beam splitter, one beam is used as the local oscillator light, and the other beam is used as the signal light. The local oscillator light can be linearly modulated by a linear modulator 1, so that the light frequency emitted by the seed source is loaded with a linear tuning frequency on the base frequency. arrive Another beam of light is modulated as signal light by an optical modulator controlled by linear modulation 2.

[0075] for Figure 4 The laser coherent ranging system is shown. The laser seed source can generate a linear Chirp signal with a repetitive period through internal modulation, and generate a trigger electrical signal at the same time. The electrical signal triggers the linear modulator 2 to generate a trigger signal 2.

[0076] In some embodiments, Figure 7 As shown, the modulation frequency of the nth pulse of the frequency-modulated pulse emitted after modulating the signal light satisfies:

[0077]

[0078] Among them, Trig sig represents the repetition period, k1 represents the frequency modulation slope of the transmitted signal, t n It means that within a cycle, with the trigger time as time 0, the time position of each transmitted signal satisfies:

[0079] (n-1)×Trig sig <t n <(n-1)×Trig sig +T sig

[0080] T sig represents the pulse width, It is expressed as the end frequency of the first linear frequency modulation pulse based on the optical frequency in the transmitted signal light. It indicates the starting frequency of the first linear frequency modulation pulse based on the optical frequency in the transmitted signal light.

[0081] In the specific implementation process, taking the frequency modulation as an example, in order to facilitate the solution, you can specify:

[0082]

[0083] k1>k0

[0084] for Figure 2 ,as well as Figure 4 The pulse laser coherent ranging system shown in the figure performs chopping on the basis of linear frequency modulation 1, and the modulation frequency of linear modulation 2 in the nth trigger cycle is:

[0085]

[0086] for Figure 3 In the pulse laser coherent ranging system shown, the frequency modulated by the linear modulator 2 is:

[0087]

[0088] (n-1)×Trig sig <t n <(n-1)×Trig sig +T sig

[0089] Among them, the repetition period is Trig sig , pulse width is T sig .

[0090] After the pulse has passed through time τ, it passes through the circulator and amplifier from the lens, is coherent with the local oscillator, and is sampled and matched filtered after passing through a band-stop or low-pass detector. The distance calculation is performed based on the matched filtering result.

[0091] During laser coherent detection, the signal light is combined with the local oscillator light after passing through a circulator and an optical amplifier, and the combined light enters the detector. Since the photodetector cannot directly detect the optical frequency, according to the basic principle of coherent detection, the sum frequency term generated after the local oscillator light and the signal light are combined cannot be detected, and only the difference frequency term can be detected, that is, the difference between the optical frequency of the echo signal and the optical frequency of the local oscillator signal. In some examples, sampling and matched filtering of the acquired echo signal include:

[0092] In some embodiments, the target is at a distance S, after After a certain time, the echo and the local oscillator light are combined. At this time, the frequency of the local oscillator light is:

[0093]

[0094] The optical frequency of the echo signal is:

[0095]

[0096] Its difference frequency f c (τ′,n) is:

[0097]

[0098] in,

[0099] (n-1)×Trig sig <t n <(n-1)×Trig sig +T sig

[0100] 0 <t n -(n-1)×Trig sig <T sig

[0101] is a fixed frequency difference, (k1-k0)×(t n -(n-1)Trig sig ) This part is a fixed linear frequency modulation signal with a modulation frequency of 0 to (k1-k0)×T sig , the modulation time is 0 to T sig That is, f c (τ′,n) has nothing to do with n, and the difference frequency result is only related to τ′. When the target distance is close, that is, τ′ <T sig , the difference frequency of N pulses is as follows Figure 8 As shown, a fixed frequency difference chirp is obtained. When the target is far away, that is, T sig <τ′ <Trig sig , the difference frequency of N pulses is as follows Fig. 9 As shown, two fixed frequency difference chirps are obtained.

[0102] From the above analysis, it can be seen that the difference frequency result is independent of N, and the bandwidth of the obtained frequency difference chirp signal is (k1-k0)×T sig , that is, the slope is constant, and the center frequency is related to the echo time τ′. In this example, according to the trigger signal for modulating the signal light, in each repetition period Trig sig Perform data collection and matched filtering processing, wherein the matched filtering processing adopts the following steps:

[0103] Determine the difference frequency f between the local oscillator light and the echo signal match The characteristic is that the slope is (k1-k0) and the frequency range satisfies:

[0104] f match_low <f match <f match_high

[0105] fmatch_low =f sig (1)-f local2

[0106] f match_high =f sig (N-1)+k1×T sig -f local1

[0107] The frequency of the difference frequency characteristic is fitted based on the frequency range, satisfying:

[0108] f match (r)=(k1-k0)×r+f match_low

[0109] Among them, r is the fitting time, which satisfies the following relationship:

[0110]

[0111] f match_high Indicates the end frequency of the designed matching frequency range, f match_low Indicates the starting frequency of the designed matching frequency range;

[0112] like Fig.10 As shown, the frequency of the fitted difference frequency characteristic determines the matched filter. When the slope is constant, f match_low Can be lowered appropriately, f match_high Can be appropriately increased.

[0113] In some embodiments, after obtaining the matched filtering results of each repetition period, the matched filtering results are accumulated to maximize the matching result value. sig After the matched filtering results are obtained, M (M ≥ N) Trig sig The results are accumulated, and the accumulated results are as follows Fig.11 as well as Fig.12 As shown. When τ′=0, according to the designed matched filter (the matched filter can be obtained based on the matching template), the matched filtering result is obtained when the horizontal coordinate is N0, and the matched filtering result value is the largest. When performing the target test, the output result is matched when the horizontal coordinate is N1 (or the horizontal coordinates N1 and N2) (that is, the output value is the largest and exceeds the detection threshold).

[0114] In some embodiments, performing distance calculation based on the result of matched filtering includes:

[0115] When there is only one matching result, the distance of the target to be measured satisfies:

[0116]

[0117] Among them, fs represents the sampling rate, N0 represents the abscissa reference of the matching result, N1 represents the abscissa value where the actual matching result is located, and c represents the speed of light;

[0118] In the case of having two matching results (N1, N2), the corresponding abscissa values are N1 and N2 respectively, and N1 < N0 < N2. If the amplitude corresponding to N2 is greater than the amplitude corresponding to N1, then the distance of the target to be measured satisfies:

[0119]

[0120] If the amplitude corresponding to N1 is greater than the amplitude corresponding to N2, then the distance of the target to be measured satisfies:

[0121]

[0122] When using a transceiver integrated pulsed laser rangefinder, at the emission moment, part of the signal light directly returns from the lens surface, and the power of this part of the signal light is relatively strong. Adopting the method of turning off the detector at the emission moment will cause the echo signal to not be detected at each emission moment, and there will be multiple blind distance points within a relatively long distance. The method of the present application uses a high-repetition-rate transceiver integrated pulsed laser coherent ranging method based on a chirped local oscillator. From the emission moment to a specified short time (such as Num is a positive integer), the frequency of the echo light exiting the lens is within the range. By selecting a band-stop or low-pass detector that does not respond in this frequency band, long-distance detection with a short blind distance can be achieved. It avoids the phenomenon that the distance cannot be measured caused by multiple blind distance points in the case of high repetition rate. When performing long-distance ranging, there is no need to change the signal light repetition rate by controlling the trigger time and perform multiple-frequency ambiguity resolution calculation; only through the design of the local oscillator light repetition rate, long-distance measurement can be achieved.

[0123] The embodiment of the present application also proposes a laser coherent ranging device, including a memory and a processor. The memory stores a computer program, and when the computer program is executed by the processor, the steps of the foregoing laser coherent ranging method are implemented.

[0124] The embodiment of the present application also proposes a computer-readable storage medium. A computer program is stored on the computer-readable storage medium, and when the computer program is executed by the processor, the steps of the foregoing laser coherent ranging method are implemented.

[0125] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0126] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0127] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, a magnetic disk, or an optical disk), and includes a number of instructions for enabling a terminal (which can be a mobile phone, a computer, a server, an air conditioner, or a network device, etc.) to execute the methods described in each embodiment of the present invention.

[0128] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation modes, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. A pulsed laser coherent ranging method based on linear frequency modulation local oscillator, characterized in that: Including: When the first linear modulator is triggered, generating a chirp signal within a preset frequency range; Based on the generated chirp signal, performing chirp modulation on the target signal, such that the optical frequency emitted by the seed source is loaded with the chirp signal on the fundamental frequency to form a first signal; Modulating the signal light, where the modulation frequency of the emitted chirp pulse after modulation is determined by the slope of the chirp signal and the pulse period. After the laser seed source undergoes linear modulation 1, it enters a beam splitter. One beam serves as the local oscillator light, and the other beam serves as the signal light. The signal light passes through an optical modulator controlled by a linear modulator 2, and then through a circulator and an amplifier, and high-power pulsed laser is emitted from the lens; Combining the modulated signal light with the first signal; After the combined optical signal passes through a detector, sampling and matched filtering processing are performed on the acquired echo signal; Performing distance calculation based on the result of the matched filtering; When the first linear modulator is triggered, generating a chirp signal within a preset frequency range includes: When the first linear modulator is triggered, the frequency generated is arrive The trigger period is 0 to Trig local Linear frequency modulation signal The slope of the linear frequency modulation signal is Among them, Trig local Determination of the maximum detectable distance based on the laser coherent ranging system; The modulation frequency of the nth pulse of the chirp pulse emitted after modulating the signal light satisfies: Among them, Trig sig represents the repetition period, k1 represents the frequency modulation slope of the transmitted signal, t n It means that within a cycle, with the trigger time as time 0, the time position of each transmitted signal satisfies: (n-1)×Trig sig <t n <(n-1)×Trig sig +T sig T sig represents the pulse width, It is expressed as the end frequency of the first linear frequency modulation pulse based on the optical frequency in the transmitted signal light. It indicates the starting frequency of the first linear frequency modulation pulse based on the optical frequency in the transmitted signal light.

2. The laser coherence ranging method according to claim 1, characterized in that: Performing matched filtering processing on the acquired echo signal includes: According to the trigger signal for modulating the signal light, data acquisition and matched filtering processing are performed in each repetition period, where the matched filtering processing adopts the following steps: Determining the frequency range of the difference frequency characteristic between the local oscillator light and the echo signal: Fitting the frequency of the difference frequency characteristic based on the frequency range, satisfying: f match (r)=(k1-k0)×r+f match_low where r is the fitting time, satisfying: f match_high Indicates the end frequency of the designed matching frequency range, f match_low Indicates the starting frequency of the designed matching frequency range; Determining a matched filter based on the fitted frequency of the difference frequency characteristic.

3. The laser coherence ranging method according to claim 2, characterized in that: After obtaining the matched filtering results of each repetition period, adding up the matched filtering results of each period to maximize the matched result value.

4. The laser coherence ranging method according to claim 3, characterized in that: Performing distance calculation based on the result of the matched filtering includes: In the case of only one matched result, the distance of the target to be measured satisfies: Among them, f s represents the sampling rate, N0 represents the horizontal coordinate reference of the matching result, N1 represents the horizontal coordinate value of the actual matching result, and c represents the speed of light; In the case of two matched results (N1, N2), the corresponding abscissa values are N1 and N2 respectively, and N1 < N0 < N2. If the amplitude corresponding to N2 is greater than the amplitude corresponding to N1, the distance of the target to be measured satisfies: If the amplitude corresponding to N1 is greater than the amplitude corresponding to N2, the distance of the target to be measured satisfies:

5. A laser coherent ranging device, characterized in that: Including a memory and a processor, the memory stores a computer program, and when the computer program is executed by the processor, it implements the steps of the laser coherent ranging method according to any one of claims 1 to 4.

6. A computer-readable storage medium, characterized in that: A computer program is stored on the computer-readable storage medium, and when the computer program is executed by the processor, it implements the steps of the laser coherent ranging method according to any one of claims 1 to 4.

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