Information detection method and system

Abstract

The invention discloses an information detection method and system, and the method comprises the steps: generating a distance measurement light beam through a distance measurement laser, dividing the distance measurement light beam into a first distance measurement light signal and a second distance measurement light signal, generating a speed measurement light beam through a speed measurement laser, and dividing the speed measurement light beam into a first speed measurement light signal and a second speed measurement light signal; moving the frequency of the first speed measurement optical signal to a specified frequency point; combining the delayed first distance measurement optical signal and the frequency-shifted first speed measurement optical signal into a path of detection optical signal, transmitting the detection optical signal into a detection space, and receiving an echo signal; combining the second distance measurement optical signal and the second speed measurement optical signal into a reference optical signal, and performing beat frequency on the reference optical signal and the echo signal to obtain a beat frequency signal; and determining speed information based on a speed measurement frequency point located in a speed frequency domain interval in two frequency points analyzed from the beat frequency signal, and determining distance information based on a distance measurement frequency point located in a distance frequency domain interval in the two frequency points.

Description

Technical Field

[0001] This application relates to the technical field of lidar, and in particular, to an information detection method and system. Background Art

[0002] In the related art, a laser modulation method can be used for target detection to detect object information of a target object in a specific space. For example, the distance between the laser and the target object, the moving speed of the target object, etc. However, the above target detection method cannot distinguish the direction of the speed, resulting in the inability to make an accurate prediction based on the object information and thus perform corresponding processing, such as target interception, target avoidance, etc.

[0003] It can be seen that in the information detection method in the related art, there is a problem that the direction of the speed cannot be measured using a single laser. Summary of the Invention

[0004] Embodiments of this application provide an information detection method and system to at least solve the problem that the direction of the speed cannot be measured using a single laser in the related art.

[0005] According to one aspect of the embodiments of this application, an information detection method is provided, including: generating a ranging beam through a ranging laser and splitting the ranging beam into a first ranging optical signal and a second ranging optical signal, and generating a velocity measurement beam through a velocity measurement laser and splitting the velocity measurement beam into a first velocity measurement optical signal and a second velocity measurement optical signal; performing a delay process on the first ranging optical signal to obtain the delayed first ranging optical signal, and shifting the frequency of the first velocity measurement optical signal to a specified frequency point to obtain the frequency-shifted first velocity measurement optical signal; combining the delayed first ranging optical signal and the frequency-shifted first velocity measurement optical signal into a detection optical signal, emitting the detection optical signal into a detection space, and receiving an echo signal; combining the second ranging optical signal and the second velocity measurement optical signal into a reference optical signal, and performing beat frequency between the reference optical signal and the echo signal to obtain a beat frequency signal; determining velocity information based on a velocity measurement frequency point located in a velocity frequency domain interval among two frequency points resolved from the beat frequency signal, and determining distance information based on a ranging frequency point located in a distance frequency domain interval among the two frequency points, where the velocity frequency domain interval is symmetric about the specified frequency point, and the velocity frequency domain interval and the distance frequency domain interval do not overlap.

[0006] According to another aspect of the embodiments of the present application, an information detection system is provided, including: a light source, a frequency shifter, a delay component, a transceiver module, and a processing module. The light source includes a ranging laser and a velocity measuring laser. Among them, the light source is configured to generate a ranging light beam through the ranging laser, and divide the ranging light beam into a first ranging optical signal and a second ranging optical signal, and generate a velocity measuring light beam through the velocity measuring laser, and divide the velocity measuring light beam into a first velocity measuring optical signal and a second velocity measuring optical signal; the delay component is configured to perform delay processing on the first ranging optical signal to obtain the delayed first ranging optical signal; the frequency shifter is configured to shift the frequency of the first velocity measuring optical signal to a specified frequency point to obtain the frequency-shifted first velocity measuring optical signal; the transceiver module is configured to combine the delayed first ranging optical signal and the frequency-shifted first velocity measuring optical signal into a detection optical signal, transmit the detection optical signal into the detection space, and receive an echo signal; the processing module is configured to combine the second ranging optical signal and the second velocity measuring optical signal into a reference optical signal, and perform beat frequency on the reference optical signal and the echo signal to obtain a beat frequency signal; determine velocity information based on the velocity measuring frequency point located in the velocity frequency domain interval among the two frequency points parsed from the beat frequency signal, and determine distance information based on the ranging frequency point located in the distance frequency domain interval among the two frequency points, where the velocity frequency domain interval is symmetric about the specified frequency point, and the velocity frequency domain interval and the distance frequency domain interval do not overlap.

[0007] In the embodiments of the present application, a ranging laser is used to generate a ranging light beam, and the ranging light beam is divided into a first ranging optical signal and a second ranging optical signal. A velocity measuring laser is used to generate a velocity measuring light beam, and the velocity measuring light beam is divided into a first velocity measuring optical signal and a second velocity measuring optical signal. The first ranging optical signal is subjected to a delay process to obtain a delayed first ranging optical signal, and the frequency of the first velocity measuring optical signal is shifted to a specified frequency point to obtain a frequency-shifted first velocity measuring optical signal. The delayed first ranging optical signal and the frequency-shifted first velocity measuring optical signal are combined into a detection optical signal, and the detection optical signal is emitted into a detection space, and an echo signal is received. The second ranging optical signal and the second velocity measuring optical signal are combined into a reference optical signal, and the reference optical signal and the echo signal are subjected to beat frequency to obtain a beat frequency signal. Velocity information is determined based on the velocity measuring frequency point located in the velocity frequency domain interval among the two frequency points parsed from the beat frequency signal, and distance information is determined based on the ranging frequency point located in the distance frequency domain interval among the two frequency points. The velocity frequency domain interval is symmetric about the specified frequency point, and the velocity frequency domain interval and the distance frequency domain interval do not overlap. Velocity measurement and ranging are respectively performed by two lasers. Among them, the ranging optical signal is subjected to a delay process, and the frequency of the velocity measuring optical signal is shifted to the specified frequency point by a frequency shifter, so that the obtained velocity frequency domain interval and distance frequency domain interval do not overlap. Furthermore, the velocity information can be determined based on the velocity measuring frequency point located in the velocity frequency domain interval, the distance information can be determined based on the ranging frequency point located in the distance frequency domain interval among the two frequency points, and the velocity direction can be determined according to the magnitude relationship between the velocity frequency point and the specified frequency point. Therefore, only a single-channel processing system (i.e., a single-channel back-end calculation system, usually including a balanced detector, a single-channel ADC, and a single-channel digital signal processor) is required to parse the distance, velocity, and direction, and further, the problem that the velocity direction cannot be measured by using a single-channel laser in the related art can be solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The accompanying drawings herein are incorporated into the specification and constitute a part of this specification, showing embodiments consistent with the present application, and are used together with the specification to explain the principles of the present application.

[0009] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the accompanying drawings required for use in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0010] Figure 1 is a schematic flowchart of an optional information detection method according to an embodiment of the present application;

[0011] Figure 2 is a schematic flowchart of another optional information detection method according to an embodiment of the present application;

[0012] Figure 3 It is a schematic diagram of an optional circulator according to an embodiment of the present application;

[0013] Figure 4 It is a schematic structural diagram of an optional information detection system according to an embodiment of the present application;

[0014] Figure 5 It is a schematic diagram of an optional information detection method according to an embodiment of the present application;

[0015] Figure 6 It is a schematic diagram of another optional information detection method according to an embodiment of the present application;

[0016] Figure 7 It is a schematic block diagram of an optional information detection system according to an embodiment of the present application;

[0017] Figure 8 It is a schematic block diagram of a computer system of an optional electronic device according to an embodiment of the present application. Detailed implementation manners

[0018] In order to enable those skilled in the art to better understand the solutions of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0019] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily need to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present application described herein can be implemented in an order different from those illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0020] According to one aspect of the embodiments of the present application, an information detection method is provided. Optionally, in this embodiment, the above information detection method can be applied to scenarios where the object information of a target object in a specific space needs to be detected. For example, it can be scenarios such as detecting the distance between a laser and a target object, the moving speed of the target object, and the speed direction, etc.

[0021] The information detection method of the embodiments of the present application can be executed by an information detection system, which may include a light source, a frequency shifter, a delay component, a transceiver module, and a processing module; the information detection system can be various types of optical ranging devices or lidars such as lidars, FMCW (Frequency Modulated Continuous Wave) radars, and optical sensors. Taking the information detection method in this embodiment executed by the information detection system as an example, Figure 1 is a schematic flowchart of an optional information detection method according to the embodiments of the present application, as Figure 1 shown, the process of this method may include the following steps:

[0022] Step S102, generating a ranging beam through a ranging laser, and splitting the ranging beam into a first ranging optical signal and a second ranging optical signal, and generating a velocity measurement beam through a velocity measurement laser, and splitting the velocity measurement beam into a first velocity measurement optical signal and a second velocity measurement optical signal.

[0023] For the ranging beam and the velocity measurement beam, the ranging beam and the velocity measurement beam refer to optical signals with specific frequencies or specific waveforms, and the modulation signals of the ranging beam and the velocity measurement beam can be triangular wave signals or DC signals, etc.

[0024] Optionally, the modulation signal of the ranging optical signal is a triangular wave signal, and the modulation signal of the velocity measurement optical signal is a DC signal.

[0025] For splitting the ranging beam into a first ranging optical signal and a second ranging optical signal, and splitting the velocity measurement beam into a first velocity measurement optical signal and a second velocity measurement optical signal, here, the way of splitting the ranging beam into a first ranging optical signal and a second ranging optical signal can be achieved by inputting the ranging beam into a beam splitter, and the beam splitter divides the ranging beam into a first ranging optical signal and a second ranging optical signal, and the same applies to the velocity measurement beam; it should be noted that a beam splitter is an optical device that divides the input beam into multiple parallel output beams.

[0026] The information detection system may include a light source, which is used to generate a ranging beam and a velocity measurement beam through a laser, and split the ranging beam and the velocity measurement beam respectively, and step S102 can be executed by the light source.

[0027] Optionally, generating a ranging beam through a ranging laser, and splitting the ranging beam into a first ranging optical signal and a second ranging optical signal, and generating a velocity measurement beam through a velocity measurement laser, and splitting the velocity measurement beam into a first velocity measurement optical signal and a second velocity measurement optical signal, includes:

[0028] Generating a ranging beam through a ranging laser, and generating a velocity measurement beam through a velocity measurement laser;

[0029] The ranging beam is divided into a first ranging optical signal and a second ranging optical signal by a first beam splitter, and the velocity measurement beam is divided into a first velocity measurement optical signal and a second velocity measurement optical signal by a second beam splitter.

[0030] In this embodiment, the light source may include a first beam splitter and a second beam splitter. A ranging beam is generated by a ranging laser, and the ranging beam is divided into a first ranging optical signal and a second ranging optical signal by the first beam splitter. A velocity measurement beam is generated by a velocity measurement laser, and the velocity measurement beam is divided into a first velocity measurement optical signal and a second velocity measurement optical signal by the second beam splitter.

[0031] It should be noted that, in this embodiment, the beam splitter may also be called a one-to-two coupler, which is used to divide a specifically input beam into two parallel output beams.

[0032] The light source may include a first beam splitter and a second beam splitter, that is, the steps of this embodiment may be jointly executed by the first beam splitter and the second beam splitter.

[0033] Step S104: Perform a delay process on the first ranging optical signal to obtain a delayed first ranging optical signal, and shift the frequency of the first velocity measurement optical signal to a specified frequency point to obtain a frequency-shifted first velocity measurement optical signal.

[0034] In this embodiment, performing a delay process on the first ranging optical signal to obtain a delayed first ranging optical signal may be achieved by serially connecting a delay optical fiber in the optical path of the first ranging optical signal. The delay optical fiber can change the optical path difference, and thus can change the frequency of the first ranging optical signal. Here, performing a delay process on the first ranging optical signal may be to increase the frequency of the first ranging optical signal.

[0035] For shifting the frequency of the first velocity measurement optical signal to a specified frequency point to obtain a frequency-shifted first velocity measurement optical signal, it may be achieved by serially connecting a frequency shifter in the optical path of the first velocity measurement optical signal. The frequency shifter can change the frequency of the first velocity measurement optical signal, and the frequency of the frequency-shifted first velocity measurement optical signal is located at the specified frequency point.

[0036] Optionally, the lowest frequency point of the delayed first ranging optical signal is greater than twice the specified frequency point, which can make the frequency range where the first ranging optical signal is located different from the frequency range where the first velocity measurement optical signal is located, so that it is easier to distinguish between the velocity measurement frequency points in the velocity frequency domain range and the ranging frequency points in the distance frequency domain range.

[0037] The information detection system may include a delay component and a frequency shifter. The delay component is used to perform a delay process on the first ranging optical signal to obtain a delayed first ranging optical signal. The frequency shifter is used to shift the frequency of the first velocity measurement optical signal to a specified frequency point to obtain a frequency-shifted first velocity measurement optical signal. Step S104 may be jointly executed by the delay component and the frequency shifter.

[0038] Step S106: Combine the delayed first ranging optical signal and the frequency-shifted first velocity measurement optical signal into a single detection optical signal, transmit the detection optical signal into the detection space, and receive the echo signal.

[0039] For combining the delayed first ranging optical signal and the frequency-shifted first velocity measurement optical signal into a single detection optical signal, it may be achieved through a beam combiner. The beam combiner can couple the first ranging optical signal and the first velocity measurement optical signal into a single detection optical signal.

[0040] After transmitting the detection optical signal into the detection space, the detection optical signal can propagate within the detection space. When there is a target object in the detection space, after the detection optical signal contacts the target object, it will be reflected back by the target object, and the information detection system can receive the reflected echo signal. Exemplarily, the information detection system may be an on-vehicle FMCW radar, and the application scenario may be a scenario where an automobile is driving on a road. The on-vehicle FMCW radar emits a single detection optical signal forward. After the detection optical signal contacts the vehicle ahead, it is reflected back, and the on-vehicle FMCW radar can receive the echo signal.

[0041] The information detection system may include a transceiver module. The transceiver module is used to combine the delayed first ranging optical signal and the frequency-shifted first velocity measurement optical signal into a single detection optical signal, transmit the detection optical signal into the detection space, and receive the echo signal. Step S106 may be executed by the transceiver module.

[0042] Step S108: Combine the second ranging optical signal and the second velocity measurement optical signal into a single reference optical signal, and perform beat frequency between the reference optical signal and the echo signal to obtain a beat frequency signal.

[0043] For combining the second ranging optical signal and the second velocity measurement optical signal into a single reference optical signal, and performing beat frequency between the reference optical signal and the echo signal to obtain a beat frequency signal, it may be achieved by using a beam combiner to combine the second ranging optical signal and the second velocity measurement optical signal into a single reference optical signal.

[0044] The information detection system may include a processing module. The processing module is used to perform beat frequency between the reference optical signal and the echo signal to obtain a beat frequency signal. Step S108 may be executed by the processing module.

[0045] Step S110: Determine the velocity information based on the velocity measurement frequency point within the velocity frequency domain interval among the two frequency points parsed from the beat frequency signal, and determine the distance information based on the distance measurement frequency point within the distance frequency domain interval among the two frequency points. Here, the velocity frequency domain interval is symmetric about a specified frequency point, and the velocity frequency domain interval and the distance frequency domain interval do not overlap.

[0046] For parsing two frequency points from the beat frequency signal, the two frequency points can be obtained by performing frequency point parsing on the beat frequency signal. For example, the beat frequency signal can be converted into a digital signal through analog-to-digital conversion, and the digital signal can be subjected to fast Fourier transform to obtain two frequency points. Since the frequencies of the first distance measurement optical signal and the first velocity measurement optical signal are distinguished in step S104, the two frequency points parsed from the beat frequency signal are respectively located in the velocity frequency domain interval and the distance frequency domain interval. The velocity information can be determined from the velocity measurement frequency point within the velocity frequency domain interval among the two frequency points parsed from the beat frequency signal, and the distance information can be determined based on the distance measurement frequency point within the distance frequency domain interval among the two frequency points.

[0047] Here, the velocity information can include the moving velocity of the detection target and the velocity direction of the moving velocity of the detection target, and the distance information can include the distance between the light source and the detection target.

[0048] The information detection system can include a processing module. The processing module is used to determine the velocity information and the distance information based on the two frequency points parsed from the beat frequency signal. Step S110 can be executed by the processing module.

[0049] Optionally, determining the velocity information based on the velocity measurement frequency point within the velocity frequency domain interval among the two frequency points parsed from the beat frequency signal, and determining the distance information based on the distance measurement frequency point within the distance frequency domain interval among the two frequency points includes:

[0050] Taking the result obtained by dividing the product of the velocity measurement frequency point and the central wavelength of the velocity measurement laser by 4 as the velocity information;

[0051] Taking the result obtained by dividing the product of the distance measurement frequency point, the speed of light, and the target modulation period by the product of 4 and the target modulation bandwidth as the distance information;

[0052] Wherein, the target modulation period is the modulation period corresponding to the detection optical signal, and the target modulation bandwidth is the modulation bandwidth corresponding to the detection optical signal.

[0053] The processing module can include a digital signal processor. The digital signal processor is used to determine the velocity information and the distance information according to the velocity measurement frequency point and the distance measurement frequency point respectively. Step S110 can be executed by the digital signal processor.

[0054] Through the embodiments provided in the present application, a ranging laser beam is generated by a ranging laser, and the ranging laser beam is divided into a first ranging optical signal and a second ranging optical signal, and a velocity measurement laser beam is generated by a velocity measurement laser, and the velocity measurement laser beam is divided into a first velocity measurement optical signal and a second velocity measurement optical signal; the first ranging optical signal is subjected to a delay process to obtain a delayed first ranging optical signal, and the frequency of the first velocity measurement optical signal is shifted to a specified frequency point to obtain a frequency-shifted first velocity measurement optical signal; the delayed first ranging optical signal and the frequency-shifted first velocity measurement optical signal are combined into a detection optical signal, the detection optical signal is emitted into a detection space, and an echo signal is received; the second ranging optical signal and the second velocity measurement optical signal are combined into a reference optical signal, and the reference optical signal and the echo signal are subjected to beat frequency to obtain a beat frequency signal; velocity information is determined based on a velocity measurement frequency point located in a velocity frequency domain interval among two frequency points resolved from the beat frequency signal, and distance information is determined based on a ranging frequency point located in a distance frequency domain interval among the two frequency points, wherein the velocity frequency domain interval is symmetric about the specified frequency point, the velocity frequency domain interval and the distance frequency domain interval do not overlap, and thus the velocity information can be determined based on the velocity measurement frequency point located in the velocity frequency domain interval, the distance information can be determined based on the ranging frequency point located in the distance frequency domain interval among the two frequency points, and the velocity direction can be determined according to the magnitude relationship between the velocity frequency point and the specified frequency point. Therefore, only a single-channel processing system (i.e., a single-channel backend calculation system, usually including a balanced detector, a single-channel ADC, and a single-channel digital signal processor) is required to resolve the distance, velocity, and direction, and thus the problem in the related art that a single-channel laser cannot measure the velocity direction can be solved.

[0055] As an optional solution, after combining the second ranging optical signal and the second velocity measurement optical signal into a reference optical signal and subjecting the reference optical signal and the echo signal to beat frequency, the method further includes:

[0056] S11, performing a fast Fourier transform on the beat frequency signal of one signal period with a sliding window of a preset length to obtain a set of sub-frequency signals, wherein each sub-frequency signal in the set of sub-frequency signals corresponds to a signal in the sliding window after one sliding in the beat frequency signal of one signal period;

[0057] S12, performing a peak search process on the set of sub-frequency signals to obtain the velocity measurement frequency point and the ranging frequency point.

[0058] In this embodiment, the length of the sliding window of the preset length is less than the length of the sliding window after one sliding, that is, after performing a long-window fast Fourier transform on the beat frequency signal, a short-window fast Fourier transform can be used. The long-window fast Fourier transform can limit the peak search interval of the short-window fast Fourier transform, thereby reducing the peak search interval, reducing interference, and improving the accuracy of information detection.

[0059] The information detection system may include a processing module, which is used to perform a fast Fourier transform on the beat frequency signal to obtain a set of sub-frequency signals, and obtain the speed measurement frequency point and the ranging frequency point based on the set of sub-frequency signals. The steps of this embodiment may be executed by the processing module.

[0060] Through this embodiment, performing a fast Fourier transform on the beat frequency signal of a signal period with a sliding window of a preset length can limit peak searching, reduce interference, and improve the accuracy of information detection.

[0061] As an alternative solution, refer to Figure 2 , Figure 2 is a schematic flowchart of another alternative information detection method according to an embodiment of the present application. As shown in Figure 2 , after performing peak searching on a set of sub-frequency signals to obtain the speed measurement frequency point and the ranging frequency point, the method further includes:

[0062] Step S202, when the speed direction of the moving speed of the detection target is the first direction and the sliding window is located in the up-sweeping frequency of the beat frequency signal of a signal period, update the ranging frequency point to the speed measurement frequency point plus the ranging frequency point minus the specified frequency point;

[0063] Step S204, when the speed direction of the moving speed of the detection target is the first direction and the sliding window is located in the down-sweeping frequency of the beat frequency signal of a signal period, update the ranging frequency point to the speed measurement frequency point plus the specified frequency point minus the ranging frequency point;

[0064] Step S206, when the speed direction of the moving speed of the detection target is the second direction and the sliding window is located in the up-sweeping frequency of the beat frequency signal of a signal period, update the ranging frequency point to the speed measurement frequency point plus the specified frequency point minus the ranging frequency point;

[0065] Step S208, when the speed direction of the moving speed of the detection target is the second direction and the sliding window is located in the down-sweeping frequency of the beat frequency signal of a signal period, update the ranging frequency point to the speed measurement frequency point plus the ranging frequency point minus the specified frequency point;

[0066] Wherein, the first direction is the direction away from the speed measurement laser, and the second direction is the direction close to the speed measurement laser.

[0067] Optionally, before executing step S202, the solution of this embodiment may further include determining the speed direction of the moving speed of the detection target based on the relationship between the speed measurement frequency point and the specified frequency point: when the speed measurement frequency point is greater than the specified frequency point, determine that the speed direction of the moving speed of the detection target is the first direction; when the speed measurement frequency point is less than the specified frequency point, determine that the speed direction of the moving speed of the detection target is the second direction.

[0068] In this embodiment, frequency sweeping refers to the process in which the frequency of a signal continuously changes from high to low (or from low to high) within a frequency band; the upper frequency sweep of the beat signal of a sliding window located in one signal period means that the sliding window is located in the signal segment where the frequency of the beat signal of one signal period changes from low to high, and the lower frequency sweep of the beat signal of a sliding window located in one signal period means that the sliding window is located in the signal segment where the frequency of the beat signal of one signal period changes from high to low.

[0069] The information detection system may include a processing module, and the processing module is configured to determine a ranging frequency point according to the velocity direction of the moving speed of the detection target and the position of the sliding window in the beat signal. The steps of this embodiment may be executed by the processing module.

[0070] The processing module may include a digital signal processor, and the digital signal processor is configured to determine a ranging frequency point according to the velocity direction of the moving speed of the detection target and the position of the sliding window in the beat signal. The steps of this embodiment may be executed by the digital signal processor.

[0071] Through this embodiment, determining the ranging frequency point according to the velocity direction of the moving speed of the detection target and the position of the sliding window in the beat signal can improve the accuracy of determining the ranging frequency point.

[0072] As an optional solution, the optical power of the first ranging optical signal is greater than the optical power of the second ranging optical signal, and the optical power of the first velocity measurement optical signal is greater than the optical power of the second velocity measurement optical signal.

[0073] In this embodiment, the ratio of the optical power of the first ranging optical signal to the optical power of the second ranging optical signal may be 90:10; the ratio of the optical power of the first velocity measurement optical signal to the optical power of the second velocity measurement optical signal may be 90:10.

[0074] Through this embodiment, the optical power of the first ranging optical signal is greater than the optical power of the second ranging optical signal, and the optical power of the first velocity measurement optical signal is greater than the optical power of the second velocity measurement optical signal, which can improve the accuracy of the information detection method.

[0075] As an optional solution, combining the second ranging optical signal and the second velocity measurement optical signal into one reference optical signal, and performing beat frequency between the reference optical signal and the echo signal to obtain a beat signal, includes:

[0076] S21, combining the second ranging optical signal and the second velocity measurement optical signal into one reference optical signal through a first beam combiner; combining the reference optical signal and the echo signal through a second beam combiner to perform beat frequency between the reference optical signal and the echo signal within the second beam combiner to obtain a beat signal, wherein the beat signal is provided by the second beam combiner to a balanced detector.

[0077] After beating the reference optical signal with the echo signal, the method further includes:

[0078] S22, performing optoelectronic conversion and analog-to-digital conversion on the beat signal in sequence through a balanced detector and an analog-to-digital converter to obtain a speed measurement frequency point and a ranging frequency point.

[0079] In this embodiment, the first beam combiner may be a two-in-one coupler for coupling two light beams into one light beam. The second beam combiner may be a 2×2 coupler or a mixer. The second beam combiner is used to beat the reference optical signal as the local oscillator signal with the echo signal to obtain a beat signal and provide the beat signal to the balanced detector.

[0080] The processing module may further include an ADC (Analog-to-Digital Converter) and a digital signal processor. The second beam combiner provides the beat signal to the balanced detector. The balanced detector performs optoelectronic conversion on the beat signal to obtain an electrical signal. The ADC performs analog-to-digital conversion on the electrical signal to obtain a digital signal (obtaining a speed measurement frequency point and a ranging frequency point). The digital signal processor processes based on the digital signal to obtain speed information and distance information.

[0081] The information detection system may include a processing module. The processing module is used to obtain a beat signal and determine a speed measurement frequency point and a ranging frequency point according to the beat signal. The steps of this embodiment may be executed by the processing module.

[0082] The processing module may include a first beam combiner, a second beam combiner, a balanced detector, and an analog-to-digital converter. The steps of this embodiment may be jointly executed by the first beam combiner, the second beam combiner, the balanced detector, and the analog-to-digital converter.

[0083] Through this embodiment, a beat signal is obtained through the first beam combiner and the second beam combiner, and a speed measurement frequency point and a ranging frequency point are determined based on the beat signal, which can improve the information detection efficiency of the information detection method.

[0084] As an alternative solution, combining the delayed first ranging optical signal and the frequency-shifted first speed measurement optical signal into one detection optical signal, emitting the detection optical signal into the detection space, and receiving the echo signal includes:

[0085] S31, combining the delayed first ranging optical signal and the frequency-shifted first speed measurement optical signal into one detection optical signal;

[0086] S32, inputting the detection optical signal into the first port of the circulator, and emitting it into the detection space through the collimator connected to the second port of the circulator and receiving the echo signal; or,

[0087] In S33, the detection optical signal is input into the first port of the circulator, and is emitted into the detection space through the optical parametric amplifier connected to the second port of the circulator, and the echo signal is received.

[0088] In this embodiment, the transceiver module may include a third beam combiner, a circulator, and a collimator. The third beam combiner is used to combine the delayed first ranging optical signal and the frequency-shifted first velocity measurement optical signal into a detection optical signal. The circulator is used to output the detection optical signal input through the first port of the circulator to the collimator through the second port of the circulator. The collimator is used to emit the detection optical signal into the detection space to obtain an echo signal. The transceiver module may also include a third beam combiner, a circulator, and an optical parametric amplifier. The third beam combiner is used to combine the delayed first ranging optical signal and the frequency-shifted first velocity measurement optical signal into a detection optical signal. The circulator is used to output the detection optical signal input through the first port of the circulator to the optical parametric amplifier through the second port of the circulator. The optical parametric amplifier is used to emit the detection optical signal into the detection space and receive the echo signal.

[0089] It should be noted that referring to Figure 3 , Figure 3 is a schematic diagram of an optional circulator according to an embodiment of the present application. As Figure 3 shown, the circulator is a multi-port optical device with non-reciprocal characteristics. When an optical signal is input from any port, it is output from the next port in numerical order with very little loss. When a signal is input from the first port, the signal can only be output from the second port. Similarly, the signal input from the second port can only be output from the third port. For emitting the detection optical signal into the detection space, the detection optical signal can be input into the first port of the circulator, and the circulator outputs the detection optical signal from the second port of the circulator to the collimator. The collimator is used to emit the detection optical signal into the detection space and receive the echo signal. The echo signal can be input into the second port of the circulator and output from the third port of the circulator. Here, the collimator belongs to an optical element for input and output in optical fiber communication optical devices. The collimator belongs to a commonly used optical device and will not be elaborated here.

[0090] The information detection system may include a transceiver module. The transceiver module is used to obtain an echo signal based on the detection optical signal. The steps of this embodiment may be executed by the transceiver module. The transceiver module may include a third beam combiner, a circulator, and a collimator. The steps of this embodiment may be jointly executed by the third beam combiner, the circulator, and the collimator. The transceiver module may include a third beam combiner, a circulator, and an optical parametric amplifier. The steps of this embodiment may be jointly executed by the third beam combiner, the circulator, and the optical parametric amplifier.

[0091] Through this embodiment, obtaining an echo signal based on the detection optical signal can improve the information detection efficiency of the information detection method.

[0092] The information detection method in this embodiment will be explained below in conjunction with an optional example. In this optional example, the information detection method can be executed by an information detection system. Referring to FIG. 4, Figure 4 is a schematic structural diagram of an optional information detection system according to an embodiment of the present application. As Figure 4 shown, the information detection system includes:

[0093] Range measurement laser M1: The range measurement laser M1 is modulated with high power, long period, and large bandwidth, for example, 25K - 8G. Referring to Figure 5 , Figure 5 where F = 25K and B = 8G. Here, the range measurement calculation period is executed by a digital signal processor, using a short-window fast Fourier transform. As Figure 5 shown, in the time-frequency signal of 25K - 8G, the entire waveform is divided along the dividing line (for example Figure 5 in which one period of the 40uS periodic signal is divided into 8 parts, each part being 5us, and then an operation of a short-window fast Fourier transform can be performed). In this way, combined with the subsequent long and short window FFT algorithms, both the calculation accuracy and the point frequency can be ensured;

[0094] Velocity measurement laser S2: The velocity measurement laser S2 modulates a DC modulation waveform to measure the speed of the detection target;

[0095] 1x2 coupler: Divides a beam of laser into two beams of laser;

[0096] 2x1 coupler: Combines two beams of laser into one beam of laser;

[0097] Frequency shifter: Shifts the frequency of the speed measurement path to point A of the frequency. The determination of the speed direction of the detection target's movement is confirmed by the speed measurement frequency point in the direction of point A of the frequency. For example, if the speed measurement frequency point is greater than the shifted frequency A, the speed is positive, that is, the detection target is moving away from the direction of the velocity measurement laser. Otherwise, it is negative;

[0098] Delay optical fiber, circulator, collimator, 2x2 coupler, balanced detector, ADC, and digital signal processor.

[0099] In this embodiment, the information detection method includes: the ranging laser M1 performs forward triangular wave modulation, and the velocity measurement laser S2 modulates a DC modulation waveform. For the ranging laser M1, after modulation (the modulation signal used is a triangular wave), a ranging light beam is generated. The ranging light beam is divided into a first ranging optical signal and a second ranging optical signal by a one-to-two coupler (in practice, the optical power of the second ranging optical signal is less than that of the first ranging optical signal. For example, the ratio of the optical power of the second ranging optical signal to that of the first ranging optical signal is 10:90); for the velocity measurement laser S2, the velocity measurement light beam is divided into a first velocity measurement optical signal and a second velocity measurement optical signal by a one-to-two coupler (in practice, the optical power of the second velocity measurement optical signal is less than that of the first velocity measurement optical signal. For example, the ratio of the optical power of the second velocity measurement optical signal to that of the first velocity measurement optical signal is 10:90), where, see Figure 6 In the optical path of the first ranging optical signal, a certain length of delay optical fiber is connected in series (the delay optical fiber can change the optical path difference, so it will change the frequency). In the optical path of the first velocity measurement optical signal, a frequency shifter is connected in series (its function is to separate the velocity measurement frequency point from the ranging frequency point. If they are mixed together, they cannot be distinguished).

[0100] Among them, the first ranging optical signal and the first velocity measurement optical signal are combined into a single detection optical signal through a two-in-one coupler and input to the first port of the circulator. The detection optical signal is output to the detection space for ranging through the collimator connected to the second port of the circulator. After being reflected by the detected object, it is also received by the collimator and output as an echo signal through the third port of the circulator. Here, the detection optical signal can also be input to an optical parametric amplifier for ranging.

[0101] The second ranging optical signal generated by the ranging laser M1 and the second velocity measurement optical signal generated by the velocity measurement laser S2 are combined into a single reference optical signal through a two-in-one coupler. The reference optical signal and the echo signal are mixed and beat through a 2×2 coupler to obtain a beat signal. The beat signal is input to a balanced detector to be converted into an electrical signal, and the electrical signal is input to an ADC to be converted into a digital signal. The ADC inputs the digital signal to a digital signal processor for processing.

[0102] For the calculation of velocity and distance: First, perform a short-window fast Fourier transform on the beat signal. After obtaining the calculation result, perform peak searching. First, judge the velocity measurement frequency point Fc and the ranging frequency point Fd, and then perform calculation after determining the two interval frequency points.

[0103] For the calculation of velocity, first determine the velocity direction of the moving speed of the detected target according to the magnitude relationship between the velocity measurement frequency point Fc and the frequency point A. If the velocity measurement frequency point is greater than the frequency shift frequency A, the velocity is positive, that is, the direction in which the detected target moves away from the velocity measurement laser. Otherwise, it is negative; the magnitude of the moving speed of the detected target is calculated according to formula (1):

[0104]

[0105] For the calculation of the distance value, first update the ranging frequency point Fd according to the velocity direction. If the velocity direction is positive, the short window is located on the up-chirp of the modulation signal, and the distance calculation frequency point is updated to F c +(F d -A). At this time, the distance between the detected target and the laser is If the velocity direction is positive and the short window is located on the down-chirp of the modulation signal, the distance calculation frequency point is updated to F c -(F d -A). At this time, the distance between the detected target and the laser is If the velocity direction is negative and the short window is located on the up-chirp of the modulation signal, the distance calculation frequency point is updated to F c -(F d -A). At this time, the distance between the detected target and the laser is If the velocity direction is negative and the short window is located on the down-chirp of the modulation signal, the distance calculation frequency point is updated to F c +(F d -A). At this time, the distance between the detected target and the laser is

[0106] Where λ is the center wavelength of the laser, C is the speed of light, B is the modulation bandwidth, and T is the modulation period.

[0107] It should be noted that for the foregoing method embodiments, for the sake of simple description, they are all expressed as a series of action combinations. However, those skilled in the art should know that this application is not limited by the described action sequence, because according to this application, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

[0108] Through the description of the above embodiments, those skilled in the art can clearly understand that the method according to the above embodiments can be implemented by means of software plus a necessary general hardware platform. Of course, it can also be implemented by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the embodiments of this application, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disc), and includes several instructions to enable a terminal device (which can be a mobile phone, computer, server, or network device, etc.) to execute the methods of the various embodiments of this application.

[0109] According to another aspect of the embodiments of the present application, an information detection system is further provided. This system is used to implement the information detection method provided in the above embodiments, and the parts that have been described will not be elaborated again. Refer to Figure 7 , Figure 7 FIG. Figure 7 is a structural block diagram of an optional information detection system according to the embodiments of the present application. As Figure 7 shown, the information detection system may include: a light source, a frequency shifter, a delay component, a transceiver module, and a processing module. The light source includes a ranging laser and a velocity measuring laser;

[0110] The light source 702 is configured to generate a ranging light beam through the ranging laser, and divide the ranging light beam into a first ranging optical signal and a second ranging optical signal, and generate a velocity measuring light beam through the velocity measuring laser, and divide the velocity measuring light beam into a first velocity measuring optical signal and a second velocity measuring optical signal;

[0111] The delay component is configured to perform delay processing on the first ranging optical signal to obtain a delayed first ranging optical signal;

[0112] The frequency shifter is configured to shift the frequency of the first velocity measuring optical signal to a specified frequency point to obtain a frequency-shifted first velocity measuring optical signal;

[0113] The transceiver module 704 is configured to combine the delayed first ranging optical signal and the frequency-shifted first velocity measuring optical signal into a detection optical signal, transmit the detection optical signal into the detection space, and receive an echo signal;

[0114] The processing module 706 is configured to combine the second ranging optical signal and the second velocity measuring optical signal into a reference optical signal, and perform beat frequency on the reference optical signal and the echo signal to obtain a beat frequency signal; determine velocity information based on the velocity measuring frequency point located in the velocity frequency domain interval among the two frequency points parsed from the beat frequency signal, and determine distance information based on the ranging frequency point located in the distance frequency domain interval among the two frequency points, where the velocity frequency domain interval is symmetric about the specified frequency point, and the velocity frequency domain interval and the distance frequency domain interval do not overlap.

[0115] Through the above information detection system, a ranging laser beam is generated by a ranging laser, and the ranging laser beam is divided into a first ranging optical signal and a second ranging optical signal, and a speed measurement laser beam is generated by a speed measurement laser, and the speed measurement laser beam is divided into a first speed measurement optical signal and a second speed measurement optical signal; the first ranging optical signal is subjected to delay processing to obtain a delayed first ranging optical signal, and the frequency of the first speed measurement optical signal is shifted to a specified frequency point to obtain a frequency-shifted first speed measurement optical signal; the delayed first ranging optical signal and the frequency-shifted first speed measurement optical signal are combined into a detection optical signal, the detection optical signal is emitted into the detection space, and an echo signal is received; the second ranging optical signal and the second speed measurement optical signal are combined into a reference optical signal, and the reference optical signal and the echo signal are subjected to beat frequency to obtain a beat frequency signal; the speed information is determined based on the speed measurement frequency point located in the speed frequency domain interval among the two frequency points resolved from the beat frequency signal, and the distance information is determined based on the ranging frequency point located in the distance frequency domain interval among the two frequency points, wherein the speed frequency domain interval is symmetric about the specified frequency point, the speed frequency domain interval and the distance frequency domain interval do not overlap, and thus the speed information can be determined based on the speed measurement frequency point located in the speed frequency domain interval, the distance information can be determined based on the ranging frequency point located in the distance frequency domain interval among the two frequency points, and the speed direction can be determined according to the magnitude relationship between the speed frequency point and the specified frequency point. Therefore, only a single-channel processing system (i.e., a single-channel backend calculation system, usually including a balanced detector, a single-channel ADC, and a single-channel digital signal processor) is required to resolve the distance, speed, and direction, and thus the problem in the related art that a single-channel laser cannot measure the speed direction can be solved.

[0116] As an optional solution, the delay component is a delay optical fiber, and the lowest frequency point of the delayed first ranging optical signal is greater than twice the specified frequency point.

[0117] As an optional solution, the light source further includes a first beam splitter and a second beam splitter, wherein the ranging laser is used to generate a ranging laser beam; the first beam splitter is used to divide the ranging laser beam into a first ranging optical signal and a second ranging optical signal; the speed measurement laser is used to generate a speed measurement laser beam; the second beam splitter is used to divide the speed measurement laser beam into a first speed measurement optical signal and a second speed measurement optical signal.

[0118] As an optional solution, the processing module includes: a first beam combiner for combining the second ranging optical signal and the second speed measurement optical signal into a reference optical signal; a second beam combiner for combining the reference optical signal and the echo signal to perform beat frequency on the reference optical signal and the echo signal in the second beam combiner to obtain a beat frequency signal, wherein the beat frequency signal is provided by the second beam combiner to a balanced detector; the balanced detector and an analog-to-digital converter are used to sequentially perform photoelectric conversion and analog-to-digital conversion on the beat frequency signal to obtain the speed measurement frequency point and the ranging frequency point.

[0119] As an alternative solution, the transceiver module includes: a third beam combiner for combining the delayed first ranging optical signal and the frequency-shifted first velocity measurement optical signal into a detection optical signal and inputting the detection optical signal into the first port of the circulator; a circulator for outputting the detection optical signal input through the first port to the collimator through the second port of the circulator; a collimator for emitting the detection optical signal into the detection space and receiving the echo signal; or a circulator for outputting the detection optical signal input through the first port to the optical parametric amplifier through the second port of the circulator; an optical parametric amplifier for emitting the detection optical signal into the detection space and receiving the echo signal.

[0120] According to another aspect of the embodiments of the present application, there is also provided a computer-readable storage medium. The computer-readable storage medium includes a stored program, wherein when the program runs, it executes the steps in any one of the above method embodiments.

[0121] In an exemplary embodiment, the above computer-readable storage medium may include, but is not limited to: USB flash drives, read-only memories (ROM for short), random access memories (RAM for short), mobile hard disks, magnetic disks, or optical discs and other various media that can store computer programs.

[0122] According to yet another aspect of the embodiments of the present application, there is also provided an electronic device, including a memory and a processor. A computer program is stored in the memory, and the processor is configured to execute the steps in any one of the above method embodiments through the computer program.

[0123] In an exemplary embodiment, the above electronic device may further include a transmission device and an input / output device, wherein the transmission device is connected to the above processor, and the input / output device is connected to the above processor.

[0124] The specific examples in this embodiment may refer to the examples described in the above embodiments and exemplary embodiments, and will not be repeated here.

[0125] According to yet another aspect of the embodiments of the present application, there is provided a computer program product. The computer program product includes computer programs / instructions, and the computer programs / instructions include program codes for executing the method shown in the flowchart. In such an embodiment, refer to Figure 8 , the computer program can be downloaded and installed from the network through the communication part 809, and / or installed from the removable medium 811. When the computer program is executed by the central processing unit 801, it executes various functions provided by the embodiments of the present application. The above serial numbers of the embodiments of the present application are only for description and do not represent the advantages and disadvantages of the embodiments.

[0126] Reference Figure 8 , Figure 8 is a block diagram of a computer system of an optional electronic device according to an embodiment of the present application.

[0127] Figure 8 Schematically shows a block diagram of a computer system of an electronic device for implementing the embodiments of the present application. As Figure 8 shown, the computer system 800 includes a central processing unit 801 (CPU), which can perform various appropriate actions and processes according to a program stored in a read-only memory 802 (ROM) or a program loaded from a storage section 808 into a random access memory 803 (RAM). In the random access memory 803, various programs and data required for system operations are also stored. The central processing unit 801, the read-only memory 802, and the random access memory 803 are connected to each other via a bus 804. An input / output interface 805 (Input / Output interface, i.e., I / O interface) is also connected to the bus 804.

[0128] The following components are connected to the input / output interface 805: an input section 806 including a keyboard, a mouse, etc.; an output section 807 including, for example, a cathode ray tube (CRT), a liquid crystal display (LCD), etc. and a speaker, etc.; a storage section 808 including a hard disk, etc.; and a communication section 809 including a network interface card such as a local area network card, a modem, etc. The communication section 809 performs communication processing via a network such as the Internet. A drive 810 is also connected to the input / output interface 805 as needed. A removable medium 811, such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc., is installed on the drive 810 as needed so that a computer program read from it can be installed into the storage section 808 as needed.

[0129] Specifically, according to the embodiments of the present application, the processes described in each method flow chart can be implemented as computer software programs. For example, the embodiments of the present application include a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program includes program codes for performing the methods shown in the flow charts. In such an embodiment, the computer program can be downloaded and installed from a network through the communication section 809, and / or installed from the removable medium 811. When the computer program is executed by the central processing unit 801, various functions defined in the system of the present application are executed.

[0130] It should be noted that Figure 8 The computer system 800 of the electronic device shown is only an example, and should not impose any limitations on the functions and usage scope of the embodiments of the present application.

[0131] Obviously, those skilled in the art should understand that the various modules or steps of the above embodiments of the present application can be implemented by a general-purpose computing device. They can be concentrated on a single computing device or distributed on a network composed of multiple computing devices. They can be implemented by program codes executable by the computing device. Thus, they can be stored in a storage device and executed by the computing device. And in some cases, the steps shown or described can be executed in a sequence different from that here, or they can be separately fabricated into individual integrated circuit modules, or multiple modules or steps among them can be fabricated into a single integrated circuit module for implementation. In this way, the embodiments of the present application are not limited to any specific combination of hardware and software.

[0132] The above are only the preferred embodiments of the present application, and are not used to limit the embodiments of the present application. For those skilled in the art, the embodiments of the present application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the principle of the embodiments of the present application shall be included in the protection scope of the embodiments of the present application.

Claims

1. An information detection method, characterized in that, Including: Generating a ranging light beam through a ranging laser, and splitting the ranging light beam into a first ranging optical signal and a second ranging optical signal, and generating a velocity measurement light beam through a velocity measurement laser, and splitting the velocity measurement light beam into a first velocity measurement optical signal and a second velocity measurement optical signal; Performing a delay process on the first ranging optical signal to obtain the delayed first ranging optical signal, and shifting the frequency of the first velocity measurement optical signal to a specified frequency point to obtain the frequency-shifted first velocity measurement optical signal; Combining the delayed first ranging optical signal and the frequency-shifted first velocity measurement optical signal into a detection optical signal, emitting the detection optical signal into a detection space, and receiving an echo signal; Combining the second ranging optical signal and the second velocity measurement optical signal into a reference optical signal, and performing beat frequency on the reference optical signal and the echo signal to obtain a beat frequency signal; Determining velocity information based on a velocity measurement frequency point located within a velocity frequency domain interval among two frequency points parsed from the beat frequency signal, and determining distance information based on a ranging frequency point located within a distance frequency domain interval among the two frequency points, wherein the velocity frequency domain interval is symmetric about the specified frequency point, and the velocity frequency domain interval and the distance frequency domain interval do not overlap.

2. The method according to claim 1, characterized in that, The performing a delay process on the first ranging optical signal to obtain the delayed first ranging optical signal includes: Performing a delay process on the first ranging optical signal through a delay optical fiber to obtain the delayed first ranging optical signal.

3. The method according to claim 2, wherein The lowest frequency point of the delayed first ranging optical signal is greater than twice the specified frequency point.

4. The method according to claim 1, characterized in that, After combining the second ranging optical signal and the second velocity measurement optical signal into a reference optical signal and performing beat frequency on the reference optical signal and the echo signal, the method further includes: Performing a fast Fourier transform on the beat frequency signal of one signal period with a sliding window of a preset length to obtain a set of sub-frequency signals, wherein each sub-frequency signal in the set of sub-frequency signals corresponds to a signal within the sliding window after one sliding in the beat frequency signal of one signal period; Performing a peak search process on the set of sub-frequency signals to obtain the velocity measurement frequency point and the ranging frequency point.

5. The method according to claim 4, characterized in that After performing a peak search process on the set of sub-frequency signals to obtain the velocity measurement frequency point and the ranging frequency point, the method further includes: When the velocity direction of the moving speed of the detection target is the first direction and the sliding window is located in the up-sweeping frequency of the beat frequency signal of one signal period, updating the ranging frequency point to the velocity measurement frequency point plus the ranging frequency point minus the specified frequency point; When the velocity direction of the moving speed of the detection target is the first direction and the sliding window is located in the down-sweeping frequency of the beat frequency signal of one signal period, updating the ranging frequency point to the velocity measurement frequency point plus the specified frequency point minus the ranging frequency point; When the velocity direction of the moving speed of the detected target is the second direction and the sliding window is located in the up-sweeping frequency of the beat frequency signal in one signal period, update the ranging frequency point to the velocity measurement frequency point plus the specified frequency point minus the ranging frequency point; When the velocity direction of the moving speed of the detected target is the second direction and the sliding window is located in the down-sweeping frequency of the beat frequency signal in one signal period, update the ranging frequency point to the velocity measurement frequency point plus the ranging frequency point minus the specified frequency point; Wherein, the first direction is the direction away from the velocity measurement laser, and the second direction is the direction towards the velocity measurement laser.

6. The method according to claim 1, characterized in that The optical power of the first ranging optical signal is greater than that of the second ranging optical signal, and the optical power of the first velocity measurement optical signal is greater than that of the second velocity measurement optical signal.

7. The method according to claim 1, wherein The combining the second ranging optical signal and the second velocity measurement optical signal into one reference optical signal, and performing beat frequency on the reference optical signal and the echo signal to obtain a beat frequency signal includes: combining the second ranging optical signal and the second velocity measurement optical signal into one reference optical signal through a first beam combiner; combining the reference optical signal and the echo signal through a second beam combiner to perform beat frequency on the reference optical signal and the echo signal in the second beam combiner to obtain the beat frequency signal, wherein the beat frequency signal is divided into two beams by the first beam combiner and provided to a balanced detector; After performing beat frequency on the reference optical signal and the echo signal, the method further includes: performing photoelectric conversion and analog-to-digital conversion on the beat frequency signal in sequence through the balanced detector and an analog-to-digital converter to obtain the velocity measurement frequency point and the ranging frequency point.

8. The method according to claim 1, wherein The combining the delayed first ranging optical signal and the frequency-shifted first velocity measurement optical signal into one detection optical signal, emitting the detection optical signal into the detection space, and receiving an echo signal includes: Combining the delayed first ranging optical signal and the frequency-shifted first velocity measurement optical signal into one detection optical signal; Inputting the detection optical signal into the first port of a circulator, and emitting it into the detection space through a collimator connected to the second port of the circulator and receiving the echo signal; or Inputting the detection optical signal into the first port of a circulator, and emitting it into the detection space through an optical parametric amplifier connected to the second port of the circulator and receiving the echo signal.

9. The method according to any one of claims 1 to 8, characterized in that, The modulation signal of the ranging optical signal is a triangular wave signal, and the modulation signal of the velocity measurement optical signal is a direct current signal.

10. An information detection system, characterized in that, Including: A light source, a frequency shifter, a delay component, a transceiver module, and a processing module. The light source includes a ranging laser and a velocity measurement laser, wherein The light source is configured to generate a ranging light beam through the ranging laser, divide the ranging light beam into a first ranging optical signal and a second ranging optical signal, generate a velocity measurement light beam through the velocity measurement laser, and divide the velocity measurement light beam into a first velocity measurement optical signal and a second velocity measurement optical signal; The delay component is configured to delay the first ranging optical signal to obtain the delayed first ranging optical signal; The frequency shifter is configured to shift the frequency of the first velocity measurement optical signal to a specified frequency point to obtain the frequency-shifted first velocity measurement optical signal; The transceiver module is configured to combine the delayed first ranging optical signal and the frequency-shifted first velocity measurement optical signal into a single detection optical signal, transmit the detection optical signal into the detection space, and receive the echo signal; The processing module is configured to combine the second ranging optical signal and the second velocity measurement optical signal into a single reference optical signal, and perform beat frequency between the reference optical signal and the echo signal to obtain a beat frequency signal; determine the velocity information based on the velocity measurement frequency point located in the velocity frequency domain interval among two frequency points resolved from the beat frequency signal, and determine the distance information based on the ranging frequency point located in the distance frequency domain interval among the two frequency points, where the velocity frequency domain interval is symmetric about the specified frequency point, and the velocity frequency domain interval and the distance frequency domain interval do not overlap.

11. The information detection system according to claim 10, characterized in that, The delay component is an optical fiber delay line, and the lowest frequency point of the delayed first ranging optical signal is greater than twice the specified frequency point.

12. The information detection system according to claim 10, wherein The light source further includes a first beam splitter and a second beam splitter, where The ranging laser is configured to generate the ranging light beam; The first beam splitter is configured to divide the ranging light beam into the first ranging optical signal and the second ranging optical signal; The velocity measurement laser is configured to generate the velocity measurement light beam; The second beam splitter is configured to divide the velocity measurement light beam into the first velocity measurement optical signal and the second velocity measurement optical signal.

13. The information detection system according to claim 12, characterized in that, The processing module includes: A first combiner configured to combine the second ranging optical signal and the second velocity measurement optical signal into a single reference optical signal; A second combiner configured to combine the reference optical signal and the echo signal to perform beat frequency between the reference optical signal and the echo signal in the second combiner to obtain the beat frequency signal, where the beat frequency signal is split into two beams by the first combiner and provided to a balanced detector; The balanced detector and the analog-to-digital converter are configured to sequentially perform photoelectric conversion and analog-to-digital conversion on the beat frequency signal to obtain the velocity measurement frequency point and the ranging frequency point.

14. The information detection system according to claim 10, wherein The transceiver module includes: A third combiner configured to combine the delayed first ranging optical signal and the frequency-shifted first velocity measurement optical signal into a single detection optical signal, and input the detection optical signal into the first port of the circulator; The circulator outputs the detection optical signal input through the first port to the collimator through the second port of the circulator; the collimator is configured to transmit the detection optical signal into the detection space and receive the echo signal; or The circulator outputs the detection optical signal input through the first port to the optical parametric amplifier through the second port of the circulator; the optical parametric amplifier is configured to transmit the detection optical signal into the detection space and receive the echo signal.

Images