Multiplexing photon Doppler velocity measurement method and device

Abstract

According to the multiplexing photon Doppler velocity measurement method and device provided by the invention, velocity measurement of M * N velocity measurement points can be realized only by a single set of device, so that velocity measurement of a large number of points is technically feasible; when two oscilloscope channels are used, speed signal retest of M * N speed measurement points can be realized, the hidden danger of test data loss caused by oscilloscope and channel faults can be effectively reduced, and the reliability is obviously improved.

Description

Technical Field

[0001] The invention relates to the technical field of laser speed measurement, and in particular to a multiplexed photon Doppler speed measurement method and device. Background Art

[0002] In the research fields of shock wave and detonation physics, explosives, high-intensity lasers, pulse power, ultra-high-speed experiments, astrophysics, weapons, etc., velocity has always been the most critical issue and the main parameter that needs to be diagnosed, such as continuous and non-contact measurement of the free surface velocity history of various materials under the action of shock waves, measurement of the velocity of flyers driven by loading technologies such as explosives, light gas guns, laser devices, and electromagnetic drives, and measurement of the velocity and acceleration of shells in artillery and shell launching systems.

[0003] Photonic Doppler Velocimetry (PDV, also known as DPS or DISAR in China) has the advantages of non-contact measurement, high time resolution, and high velocity measurement accuracy. It has been widely used and has become the main means of velocity measurement.

[0004] The existing laser velocity measurement technology can only measure a limited number of points on the object to be measured, but with the deepening of related research, the requirement of array-type or area coverage velocity measurement of a large number of points on the object to be measured has been proposed, such as simultaneous velocity measurement of multiple objects, spatiotemporal inhomogeneity of strong shock waves, velocity change history of each point on the target surface loaded by laser or electromagnetic over time, velocity distribution and relative difference of the entire surface of the sample at one or more moments, etc. The development trend of laser velocity measurement technology has also put forward the same requirement, and defined the new optical velocity measurement equipment that realizes this requirement as the latest generation of optical velocity measurement equipment. At present, my country has a clear and urgent demand for this.

[0005] In traditional speed measuring equipment such as PDV, one measuring point requires at least one recording channel (including one detector and one oscilloscope channel), and generally one speed measuring host can only measure 4 to 8 speed measuring points at most. The measurement of more points needs to be achieved by superimposing multiple hosts. However, with the increase in the number of speed measuring points, the complexity, cost and volume of the entire system (especially the recording channel) increase significantly. Therefore, it is difficult to use the simple superposition method of PDV to achieve speed measurement of a large number of points (dozens or even hundreds of points), and other speed measuring technologies have more prominent problems in this regard. Summary of the invention

[0006] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a multiplexed photon Doppler velocity measurement method and device, which is specifically achieved through the following technical solutions:

[0007] The present invention provides a multiplexed photon Doppler speed measuring device, comprising:

[0008] N detection light lasers of different wavelengths, each of which is used to output a DC detection light, and the N detection light lasers output a total of N channels of DC detection light of different wavelengths;

[0009] N modulators, the modulators are connected to the output end of each detection light laser, and the N modulators are used to modulate N channels of DC detection light into N channels of pulsed detection light; the duration of each channel of the pulsed detection light covers and only covers the duration of the speed signal to be measured;

[0010] N optical fiber beam splitters, the optical fiber beam splitters are connected to the output end of the modulator, each optical fiber beam splitter is used to split the pulsed detection light of the access path into M detection lights; the N optical fiber beam splitters split the N pulsed detection lights into M×N detection lights;

[0011] M wavelength division multiplexers A, M circulators, M wavelength division multiplexers B and M×N speed measuring probes, one of the light paths separated by each optical fiber beam splitter is inputted to each wavelength division multiplexer A without duplication, each wavelength division multiplexer A combines N paths of light from N optical fiber beam splitters into one path of light, and then splits the path of light into N paths of light through the circulator and the wavelength division multiplexer B, and then enters N different speed measuring probes; since the N optical fiber beam splitters divide the N paths of pulsed detection light into M×N paths of detection light, the M wavelength division multiplexers A combine the M×N paths of detection light into M paths of light, the M circulators and the M wavelength division multiplexers B divide the M paths of light into M×N paths of light, and the M×N paths of light enter the M×N speed measuring probes respectively, and then illuminate the moving target to be measured, forming M×N speed measuring points;

[0012] Each speed measuring probe returns a pulse signal light with speed information, which then passes through the wavelength division multiplexer B and the circulator in turn to be multiplexed into a group of pulse signal lights; M×N speed measuring point speed measuring probes return M×N pulse signal lights, which are then multiplexed into M groups of pulse signal lights;

[0013] Each group of pulsed signal lights enters the first fiber coupler after being amplified by the amplifier and delayed by the delay line. There is an equidistant delay between each group of pulsed signal lights, and the interval time is the duration of the pulsed detection light. The M groups of pulsed signal lights are coupled into one light by the first fiber coupler and then input into the second fiber coupler.

[0014] N reference lasers, the wavelengths of the N reference lasers correspond one to one with the wavelengths of the N detection light lasers; the N reference lights output by the N reference lasers are multiplexed and power-adjusted by the wavelength division multiplexer C and combined into one light, which is input to the second optical fiber coupler;

[0015] The optical fiber coupler 2 interferes with the two light beams and enters the detector to be converted into a voltage signal, which is recorded and processed by the oscilloscope to achieve speed measurement of M×N speed measurement points.

[0016] Optionally or preferably, the number of the detection light lasers is N; the optical fiber beam splitter is used to split the pulsed detection light into M pieces; wherein, the recommended values ​​of N and M are both not less than 2.

[0017] Optionally or preferably, the oscilloscope has 1-2 channels.

[0018] The present invention provides a multiplexed photon Doppler velocity measurement method, comprising the following steps:

[0019] S1, N detection light lasers emit N channels of DC detection light;

[0020] S2, N modulators modulate the DC detection lights emitted by N detection light lasers respectively to modulate them into N pulse detection lights;

[0021] S3, splitting N pulsed detection lights by using N optical fiber beam splitters, each pulsed detection light is divided into M detection lights, and the N pulsed detection lights are divided into M×N detection lights in total;

[0022] S4, inputting the M paths of light split by each optical fiber beam splitter into M different wavelength division multiplexers A respectively, that is, each wavelength division multiplexer A simultaneously receives N paths of light from N optical fiber beam splitters; the wavelength division multiplexer A multiplexes the received light beams and outputs them as one path of light;

[0023] S5. The output optical path of each wavelength division multiplexer A is split by a circulator and a wavelength division multiplexer B. The output optical path of each wavelength division multiplexer A is divided into N paths. M circulators and M wavelength division multiplexers B split M different wavelength division multiplexers A into M×N paths of light. The M×N paths of light are respectively input into M×N speed measuring probes and irradiated onto the moving target to be measured, forming M×N speed measuring points.

[0024] S6. The surface of the moving target to be measured will reflect the detection light. Based on the Doppler frequency shift, the speed of the moving target to be measured will cause the reflected detection light to carry the speed information of the moving target to be measured. The reflected detection light is the signal light.

[0025] S7, the speed measuring probe collects signal lights from M×N speed measuring points, and multiplexes the M×N signal lights into M groups of pulse signal lights through M wavelength division multiplexers B and M circulators;

[0026] S8, amplifying the M groups of pulsed signal lights obtained in step S7;

[0027] S9, performing equal delay on the M groups of pulse signal lights processed in step S8;

[0028] S10, inputting the M groups of pulsed signal lights processed in step S9 into coupler 1, which couples them into one light beam and inputs it into coupler 2;

[0029] S11, coupler 2 receives the light beam processed in step S10 and the multi-wavelength reference light beam set, interferes the two beams, and forms an interference light beam through wavelength division multiplexing;

[0030] S12, the detector receives the interference light generated in step S11 and converts it into a voltage signal;

[0031] S13. Record and process the voltage signal generated in step S12 by an oscilloscope to achieve speed measurement of M×N speed measurement points.

[0032] Optionally or preferably, in step S9, when the M groups of pulsed signal lights are equally delayed, specifically:

[0033] The first group of pulsed signal lights is not delayed, so that the first group of pulsed signal lights is directly used as the subsequent input; a group of delay lines is added to the optical channel of the second group of pulsed signal lights, so that the second group of pulsed signal lights is delayed by ΔT and used as the subsequent input;

[0034] …

[0035] Adding M-2 groups of delay lines to the optical channel of the M-1 group of pulsed signal light, so that the M-1 group of pulsed signal light is delayed by (M-2)×ΔT and used as subsequent input;

[0036] Add M-1 groups of delay lines to the optical channel of the Mth group of pulsed signal light, so that the Mth group of pulsed signal light is delayed by (M-1)×ΔT and used as subsequent input.

[0037] Optionally or preferably, the multi-wavelength reference beam set is generated by the following steps:

[0038] T1. Configure N reference light lasers so that the N reference light lasers emit N reference lights, and the wavelengths of the reference lights correspond one to one with the wavelengths of the DC detection lights in step S1, that is:

[0039] λ iR =λ i +Δi

[0040] Among them, λ iR is the wavelength of the reference light emitted by the i-th reference laser; iis the wavelength of the DC detection light emitted by the i-th detection light laser; Δi is the wavelength difference between the i-th reference laser and the i-th detection light laser, and Δi belongs to the i-th item in the monotonic sequence {Δn}: Δ1, Δ2, …, Δn;

[0041] T2, multiplexing the reference light generated in step T1 through a dense wavelength division multiplexer;

[0042] T3. Adjust the power of the reference light generated in step T2 through an adjustable attenuator to obtain a multi-wavelength reference beam.

[0043] Optionally or preferably, the step S13 comprises the following steps:

[0044] S1301, input the voltage signal into the first channel of the oscilloscope, and record it as the main measurement signal;

[0045] S1302, performing time-frequency processing on the main measurement signal, and obtaining the change of the speed measured at each speed measurement point relative to the static reference speed from the speed spectrum generated by interference;

[0046] S1303. By wavelength division multiplexing, all speed signals generated by all detection lights multiplexed by the same wavelength division multiplexer B are taken as the same group of speed signals, all speed measurement points belonging to the same group of speed signals are taken as the same group of speed measurement points, and the speed signals of each group of speed measurement points are multiplexed into a group of time division signals.

[0047] Optionally or preferably, the step S13 comprises the following steps:

[0048] S1311, dividing the voltage signal into a first voltage signal and a second voltage signal;

[0049] S1312, inputting the first voltage signal into the first channel of the oscilloscope, and recording it as the main measurement signal;

[0050] S1313, performing time-frequency processing on the main measurement signal, and obtaining the change of the speed measured at each speed measurement point relative to the static reference speed from the speed spectrum generated by interference;

[0051] S1314, by wavelength division multiplexing, all speed signals generated by all detection lights multiplexed by the same wavelength division multiplexer B are taken as the same group of speed signals, all speed measurement points belonging to the same group of speed signals are taken as the same group of speed measurement points, and the speed signals of each group of speed measurement points are multiplexed into a group of time division signals;

[0052] S1315, input the second voltage signal into the second channel of the oscilloscope, and perform the same processing as the first voltage signal, thereby realizing signal retesting.

[0053] Optionally or preferably, in step S1311, the voltage signal may be split by an electronic power divider or an electronic three-way connector.

[0054] Based on the above technical solution, the following technical effects can be produced:

[0055] 1. A single device can be used to measure the speed of M×N speed measurement points, making speed measurement at a large number of points technically feasible;

[0056] 2. Only two oscilloscope channels are needed to achieve speed signal retesting of M×N speed measurement points, which can effectively reduce the risk of test data loss due to oscilloscope and channel failures, significantly increase reliability, and can adapt to unpredictable dynamic changes in interference signal amplitude by setting high sensitivity and low sensitivity amplitude ranges on two oscilloscope channels, significantly improving the test effect. Conventional devices and methods require 2*N*M detectors and 2*N*M oscilloscope channels to achieve signal retesting of the same number of measurement points;

[0057] 3. Greatly reduce the number of oscilloscopes and detectors required, when no signal retest is performed, the number is reduced to 1 / (M×N), when signal retest is performed, the number of detectors is reduced to 1 / (2×M×N) and the number of oscilloscopes is reduced to 1 / (M×N), making the speed measurement of a large number of points feasible in terms of hardware resources (hardware resources are limited, and conventional methods and devices are not easy to implement when the number of measurement points is large, especially signal retest cannot be achieved);

[0058] 4. All M×N speed measurement points can realize optical heterodyne speed measurement, that is, up-conversion heterodyne can be used to improve the time resolution and measurement accuracy of the speed, and down-conversion heterodyne can be used to reduce the bandwidth requirements of the system, and the two methods are easy to switch;

[0059] 5. Each group of time-division signals contains multiple speed signals of multiple wavelengths (rather than the conventional single wavelength or single speed signal). The speed signals in the group are isolated by wavelength differences. Each group of time-division signals is modulated into pulse signals with different starting points by a high-power single-channel optical fiber intensity modulator, so that the speed signal crosstalk of all measuring points can be effectively eliminated. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0061] Figure 1It is a schematic diagram of the structural connection of the detection light laser, the detection light output optical path and the signal light return optical path;

[0062] Figure 2 It is a schematic diagram of the structural connection of the multiplexed optical path and the signal recording part;

[0063] Figure 3 The wavelength division and time division joint multiplexed speed measurement signals of M×N speed measurement points obtained for one recording channel (wavelength division multiplexing in the vertical direction and time division multiplexing in the horizontal direction). DETAILED DESCRIPTION

[0064] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0065] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0066] Embodiment 1:

[0067] like Figure 1-Figure 3 As shown:

[0068] The present invention provides a multiplexed photon Doppler speed measuring device, comprising:

[0069] N detection light lasers with different wavelengths, each of which is used to output DC detection light, and the N detection light lasers output N channels of DC detection light with different wavelengths; specifically, when setting the wavelength of the detection light laser, it is set to the ITUDWDM standard wavelength;

[0070] N modulators, the modulators are connected to the output end of each detection light laser, and the N modulators are used to modulate N channels of DC detection light into N channels of pulsed detection light; the duration of each channel of the pulsed detection light covers and only covers the duration of the speed signal to be measured; specifically, the modulator is a high-power single-channel high-speed optical fiber intensity modulator or a high-power 1*1 single-channel high-speed optical switch; the modulator is directly added to the output end of the detection light laser because the target to be measured is basically started at the same or similar time, and the speed signal duration is basically the same, so the N modulators only need to use 1 modulation signal (equally divided into N channels), instead of the conventional N-channel control signal, which effectively reduces the requirements for the modulation signal and the equipment;

[0071] N optical fiber beam splitters, the optical fiber beam splitters are connected to the output end of the modulator, each optical fiber beam splitter is used to split the pulsed detection light of the access path into M detection lights; the N optical fiber beam splitters split the N pulsed detection lights into M×N detection lights;

[0072] M wavelength division multiplexers A, M circulators, M wavelength division multiplexers B and M×N speed measuring probes, one of the light paths separated by each optical fiber beam splitter is inputted to each wavelength division multiplexer A without duplication, each wavelength division multiplexer A combines N paths of light from N optical fiber beam splitters into one path of light, and then splits the path of light into N paths of light through the circulator and the wavelength division multiplexer B, and then enters N different speed measuring probes; since the N optical fiber beam splitters divide the N paths of pulsed detection light into M×N paths of detection light, the M wavelength division multiplexers A combine the M×N paths of detection light into M paths of light, the M circulators and the M wavelength division multiplexers B divide the M paths of light into M×N paths of light, and the M×N paths of light enter the M×N speed measuring probes respectively, and then illuminate the moving target to be measured, forming M×N speed measuring points;

[0073] Each speed measuring probe returns a pulse signal light with speed information, which then passes through the wavelength division multiplexer B and the circulator in turn to be multiplexed into a group of pulse signal lights; M×N speed measuring point speed measuring probes return M×N pulse signal lights, which are then multiplexed into M groups of pulse signal lights;

[0074] Each group of pulsed signal lights enters the first fiber coupler after being amplified by the amplifier and delayed by the delay line. There is an equidistant delay between each group of pulsed signal lights, and the interval time is the duration of the pulsed detection light. The M groups of pulsed signal lights are coupled into one light by the first fiber coupler and then input into the second fiber coupler.

[0075] N reference lasers, the wavelengths of the N reference lasers correspond one to one with the wavelengths of the N detection light lasers; the N reference lights output by the N reference lasers are multiplexed and power-adjusted by the wavelength division multiplexer C and combined into one light, which is input to the second optical fiber coupler;

[0076] The optical fiber coupler 2 interferes with the two light beams and enters the detector to be converted into a voltage signal, which is recorded and processed by the oscilloscope to achieve speed measurement of M×N speed measurement points.

[0077] Specifically, it is recommended that the values ​​of N and M be no less than 2; for example, N and M can be 4 or 8.

[0078] The present invention also provides a multiplexed photon Doppler velocity measurement method, comprising the following steps:

[0079] S1, N detection light lasers emit N channels of DC detection light;

[0080] S2, N modulators modulate the DC detection light emitted by N detection light lasers respectively into N pulse detection lights with a duration of ΔT; ΔT directly corresponds to the duration of the target speed signal to be measured, and the time other than ΔT is completely cut off (extinction ratio ≥ 50dB), thereby ensuring that there is only a valid signal during the speed duration, and there is no additional optical signal that can cause crosstalk at other times;

[0081] S3, splitting N pulsed detection lights by using N optical fiber beam splitters, each pulsed detection light is divided into M detection lights, and the N pulsed detection lights are divided into M×N detection lights in total;

[0082] S4, such as Figure 1 As shown, the M paths of light split by each optical fiber beam splitter are respectively input to M different wavelength division multiplexers A, that is, each wavelength division multiplexer A simultaneously receives N paths of light from N optical fiber beam splitters; the wavelength division multiplexer A multiplexes the received light beams and outputs them as one path of light;

[0083] S5. The output optical path of each wavelength division multiplexer A is split by a circulator and a wavelength division multiplexer B. The output optical path of each wavelength division multiplexer A is divided into N paths. M circulators and M wavelength division multiplexers B split M different wavelength division multiplexers A into M×N paths of light. The M×N paths of light are respectively input into M×N speed measuring probes and irradiated onto the moving target to be measured, forming M×N speed measuring points.

[0084] S6. The surface of the moving target to be measured will reflect the detection light. Based on the Doppler frequency shift, the speed of the moving target to be measured will cause the reflected detection light to carry the speed information of the moving target to be measured. The reflected detection light is the signal light.

[0085] S7, the speed measuring probe collects signal lights from M×N speed measuring points, and multiplexes the M×N signal lights into M groups of pulse signal lights through M wavelength division multiplexers B and M circulators;

[0086] Among them, the second to Mth paths separated by N detection light lasers have detection light output and signal light return paths that are the same as Figure 1 The first paths within the dashed boxes are identical, so they are no longer shown in their entirety;

[0087] S8, amplifying the M groups of pulsed signal lights obtained in step S7;

[0088] S9, performing equal delay on the M groups of pulse signal lights processed in step S8;

[0089] S10, inputting the M groups of pulsed signal lights processed in step S9 into coupler 1, which couples them into one light beam and inputs it into coupler 2;

[0090] S11, coupler 2 receives the light beam processed in step S10 and the multi-wavelength reference light beam set, interferes the two beams, and forms an interference light beam through wavelength division multiplexing;

[0091] Since the multi-wavelength reference light and the detection light have a certain wavelength difference, the interference generated by the two is optical heterodyne interference. Up-conversion heterodyne velocity measurement or down-conversion heterodyne velocity measurement can be achieved by changing the wavelength of the reference light.

[0092] S12, the detector receives the interference light generated in step S11 and converts it into a voltage signal;

[0093] S13. Record and process the voltage signal generated in step S12 by an oscilloscope to achieve speed measurement of M×N speed measurement points.

[0094] In this embodiment, when the M groups of pulsed signal lights are equally delayed in step S9, specifically:

[0095] The first group of pulsed signal lights is not delayed, so that the first group of pulsed signal lights is directly used as the subsequent input; a group of delay lines is added to the optical channel of the second group of pulsed signal lights, so that the second group of pulsed signal lights is delayed by ΔT and used as the subsequent input;

[0096] …

[0097] Adding M-2 groups of delay lines to the optical channel of the M-1 group of pulsed signal light, so that the M-1 group of pulsed signal light is delayed by (M-2)×ΔT and used as subsequent input;

[0098] Add M-1 groups of delay lines to the optical channel of the Mth group of pulsed signal light, so that the Mth group of pulsed signal light is delayed by (M-1)×ΔT and used as subsequent input.

[0099] In this embodiment, the multi-wavelength reference beam set is generated by the following steps:

[0100] T1. Configure N reference light lasers so that the N reference light lasers emit N reference lights, and the wavelengths of the reference lights correspond one to one with the wavelengths of the DC detection lights in step S1, that is:

[0101] λ iR =λ i +Δi

[0102] Among them, λ iR is the wavelength of the reference light emitted by the i-th reference laser; iis the wavelength of the DC detection light emitted by the i-th detection light laser; Δi is the wavelength difference between the i-th reference laser and the i-th detection light laser, and Δi belongs to the i-th item in the monotonic sequence {Δn}: Δ1, Δ2, …, Δn; further, the sequence {Δn} is an arithmetic increasing sequence or an unequally increasing sequence;

[0103] T2, multiplexing the reference light generated in step T1 through a dense wavelength division multiplexer;

[0104] T3. Adjust the power of the reference light generated in step T2 through an adjustable attenuator to obtain a multi-wavelength reference beam.

[0105] Furthermore, when the wavelength of the reference light is longer (i.e., the above Δi is a positive value), it is an up-conversion heterodyne speed measurement, there is an initial static speed that is not zero (its value corresponds to Δi), and the speed curve in the dynamic stage increases on its basis (up to the speed value corresponding to the system bandwidth), thereby improving the time resolution and measurement accuracy. When the wavelength of the reference light is shorter (i.e., the above Δi is a negative value), it is a down-conversion heterodyne speed measurement, there is also an initial static speed that is not zero (its value corresponds to Δi), and the speed curve in the dynamic stage first decreases to zero and then increases on its basis (up to the speed value corresponding to the system bandwidth), thereby increasing the speed measurement range, or reducing the system bandwidth requirement when the speed measurement range is the same.

[0106] In this embodiment, step S13 includes the following steps:

[0107] S1311, dividing the voltage signal into a first voltage signal and a second voltage signal through an electronic power divider or an electronic three-way connector;

[0108] S1312, inputting the first voltage signal into the first channel of the oscilloscope, and recording it as the main measurement signal;

[0109] S1313, performing time-frequency processing on the main measurement signal, and obtaining the change of the speed measured at each speed measurement point relative to the static reference speed from the speed spectrum generated by interference;

[0110] S1314, by wavelength division multiplexing, all speed signals generated by all detection lights multiplexed by the same wavelength division multiplexer B are taken as the same group of speed signals, all speed measurement points belonging to the same group of speed signals are taken as the same group of speed measurement points, and the speed signals of each group of speed measurement points are multiplexed into a group of time division signals;

[0111] like Figure 3The figure shows the velocity spectrum generated by interference. It can be seen that because {Δn}: Δ1, Δ2, ..., Δn is an increasing series, the velocity curves of the first group of velocity measurement points 1-1, 2-1, ..., N-1 are changed in turn based on static velocities of different magnitudes, that is, through the wavelength division multiplexing method, the velocity signals of the first group of N velocity measurement points are multiplexed into the first group of time division signals of the velocity spectrum (starting point 0, duration ΔT), and are separated in sequence in the longitudinal direction, and can be processed again later to obtain separate velocity signals of the N velocity measurement points; the second to Mth groups of time division signals are processed in the same way;

[0112] S1315, input the second voltage signal into the second channel of the oscilloscope, and perform the same processing on it as the first voltage signal, so as to achieve signal retest.

[0113] For example, 8 groups of lasers, 1 1x4 optical switch, 1 detector and 1 oscilloscope channel can realize 32-point wavelength division and time division joint multiplexing speed measurement of a single device; 8 groups of lasers, 1 1x8 optical switch, 1 detector and 1 oscilloscope channel can realize 64-point wavelength division and time division joint multiplexing speed measurement of a single device; 16 groups of lasers, 1 1x16 optical switch, 1 detector and 1 oscilloscope channel can realize 256-point wavelength division and time division joint multiplexing speed measurement of a single device.

[0114] The above is only a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art shall not deviate from the spirit and scope of the present invention, and shall be within the scope of protection of the claims attached to the present invention.

Claims

1. A multiplexed photon Doppler speed measurement device, characterized in that: include: N detection light lasers of different wavelengths, each of which is used to output a DC detection light, and the N detection light lasers output a total of N channels of DC detection light of different wavelengths; N modulators, the modulators are connected to the output end of each detection light laser, and the N modulators are used to modulate N channels of DC detection light into N channels of pulsed detection light; the duration of each channel of the pulsed detection light covers and only covers the duration of the speed signal to be measured; N optical fiber beam splitters, the optical fiber beam splitters are connected to the output end of the modulator, and each optical fiber beam splitter is used to split the pulsed detection light of the access path into M detection lights; N optical fiber beam splitters divide N pulsed detection lights into M×N detection lights; M wavelength division multiplexers A, M circulators, M wavelength division multiplexers B and M×N speed measuring probes, one of the light paths separated by each optical fiber beam splitter is inputted to each wavelength division multiplexer A without duplication, each wavelength division multiplexer A combines N paths of light from N optical fiber beam splitters into one path of light, and then splits the path of light into N paths of light through the circulator and the wavelength division multiplexer B, and then enters N different speed measuring probes; since the N optical fiber beam splitters divide the N paths of pulsed detection light into M×N paths of detection light, the M wavelength division multiplexers A combine the M×N paths of detection light into M paths of light, the M circulators and the M wavelength division multiplexers B divide the M paths of light into M×N paths of light, and the M×N paths of light enter the M×N speed measuring probes respectively, and then illuminate the moving target to be measured, forming M×N speed measuring points; Each speed measuring probe returns a pulse signal light with speed information, which then passes through the wavelength division multiplexer B and the circulator in turn to be multiplexed into a group of pulse signal lights; M×N speed measuring point speed measuring probes return M×N pulse signal lights, which are then multiplexed into M groups of pulse signal lights; Each group of pulsed signal lights enters the first fiber coupler after being amplified by the amplifier and delayed by the delay line. There is an equidistant delay between each group of pulsed signal lights, and the interval time is the duration of the pulsed detection light. The M groups of pulsed signal lights are coupled into one light by the first fiber coupler and then input into the second fiber coupler. N reference lasers, the wavelengths of the N reference lasers correspond one to one with the wavelengths of the N detection light lasers; the N reference lights output by the N reference lasers are multiplexed and power-adjusted by the wavelength division multiplexer C and combined into one light, which is input to the second optical fiber coupler; The optical fiber coupler 2 interferes with the two light beams and enters the detector to be converted into a voltage signal, which is recorded and processed by the oscilloscope to achieve speed measurement of M×N speed measurement points.

2. A multiplexed photon Doppler speed measuring device according to claim 1, characterized in that: The number of the detection light lasers is N; the optical fiber beam splitter is used to split the pulsed detection light into M pieces; wherein the values ​​of N and M are not less than 2.

3. A multiplexed photon Doppler speed measurement device according to claim 1, characterized in that: The oscilloscope has 1-2 channels.

4. A multiplexed photon Doppler velocity measurement method, characterized in that: The following steps are involved: S1, N detection light lasers emit N channels of DC detection light; S2, N modulators modulate the DC detection lights emitted by N detection light lasers respectively to modulate them into N pulse detection lights; S3, splitting N pulsed detection lights by using N optical fiber beam splitters, each pulsed detection light is divided into M detection lights, and the N pulsed detection lights are divided into M×N detection lights in total; S4, inputting the M paths of light split by each optical fiber beam splitter into M different wavelength division multiplexers A respectively, that is, each wavelength division multiplexer A simultaneously receives N paths of light from N optical fiber beam splitters; the wavelength division multiplexer A multiplexes the received light beams and outputs them as one path of light; S5. The output optical path of each wavelength division multiplexer A is split by a circulator and a wavelength division multiplexer B. The output optical path of each wavelength division multiplexer A is divided into N paths. M circulators and M wavelength division multiplexers B split M different wavelength division multiplexers A into M×N paths of light. The M×N paths of light are respectively input into M×N speed measuring probes and irradiated onto the moving target to be measured, forming M×N speed measuring points. S6. The surface of the moving target to be measured will reflect the detection light. Based on the Doppler frequency shift, the speed of the moving target to be measured will cause the reflected detection light to carry the speed information of the moving target to be measured. The reflected detection light is the signal light. S7, the speed measuring probe collects signal lights from M×N speed measuring points, and multiplexes the M×N signal lights into M groups of pulse signal lights through M wavelength division multiplexers B and M circulators; S8, amplifying the M groups of pulsed signal lights obtained in step S7; S9, performing equal delay on the M groups of pulse signal lights processed in step S8; S10, inputting the M groups of pulsed signal lights processed in step S9 into coupler 1, which couples them into one light beam and inputs it into coupler 2; S11, coupler 2 receives the light beam processed in step S10 and the multi-wavelength reference light beam set, interferes the two beams, and forms an interference light beam through wavelength division multiplexing; S12, the detector receives the interference light generated in step S11 and converts it into a voltage signal; S13. Record and process the voltage signal generated in step S12 by an oscilloscope to achieve speed measurement of M×N speed measurement points.

5. A multiplexed photon Doppler velocity measurement method according to claim 4, characterized in that: When the M groups of pulse signal lights are equally delayed in step S9, specifically: The first group of pulsed signal lights is not delayed, so that the first group of pulsed signal lights is directly used as the subsequent input; a group of delay lines is added to the optical channel of the second group of pulsed signal lights, so that the second group of pulsed signal lights is delayed by ΔT and used as the subsequent input; …… Adding M-2 groups of delay lines to the optical channel of the M-1 group of pulsed signal light, so that the M-1 group of pulsed signal light is delayed by (M-2)×ΔT and used as subsequent input; Add M-1 groups of delay lines to the optical channel of the Mth group of pulsed signal light, so that the Mth group of pulsed signal light is delayed by (M-1)×ΔT and used as subsequent input.

6. A multiplexed photon Doppler velocity measurement method according to claim 4, characterized in that: The multi-wavelength reference beam set is generated by the following steps: T1. Configure N reference light lasers so that the N reference light lasers emit N reference lights, and the wavelengths of the reference lights correspond one to one with the wavelengths of the DC detection lights in step S1, that is: l iR =λ i +Dn Among them, λ iR is the wavelength of the reference light emitted by the i-th reference laser; i is the wavelength of the DC detection light emitted by the i-th detection light laser; Δi is the wavelength difference between the i-th reference laser and the i-th detection light laser, and Δi belongs to the i-th item in the monotonic sequence {Δn}: Δ1, Δ2, …, Δn; T2, multiplexing the reference light generated in step T1 through a dense wavelength division multiplexer; T3. Adjust the power of the reference light generated in step T2 by an adjustable attenuator to obtain a multi-wavelength reference beam.

7. A multiplexed photon Doppler velocity measurement method according to claim 4, characterized in that: The step S13 comprises the following steps: S1301, input the voltage signal into the first channel of the oscilloscope, and record it as the main measurement signal; S1302, performing time-frequency processing on the main measurement signal, and obtaining the change of the speed measured at each speed measurement point relative to the static reference speed from the speed spectrum generated by interference; S1303. By wavelength division multiplexing, all speed signals generated by all detection lights multiplexed by the same wavelength division multiplexer B are taken as the same group of speed signals, all speed measurement points belonging to the same group of speed signals are taken as the same group of speed measurement points, and the speed signals of each group of speed measurement points are multiplexed into a group of time division signals.

8. A multiplexed photon Doppler velocity measurement method according to claim 4, characterized in that: The step S13 comprises the following steps: S1311, dividing the voltage signal into a first voltage signal and a second voltage signal; S1312, inputting the first voltage signal into the first channel of the oscilloscope, and recording it as the main measurement signal; S1313, performing time-frequency processing on the main measurement signal, and obtaining the change of the speed measured at each speed measurement point relative to the static reference speed from the speed spectrum generated by interference; S1314, by wavelength division multiplexing, all speed signals generated by all detection lights multiplexed by the same wavelength division multiplexer B are taken as the same group of speed signals, all speed measurement points belonging to the same group of speed signals are taken as the same group of speed measurement points, and the speed signals of each group of speed measurement points are multiplexed into a group of time division signals; S1315, input the second voltage signal into the second channel of the oscilloscope, and perform the same processing on it as the first voltage signal, so as to achieve signal retest.

9. A multiplexed photon Doppler velocity measurement method according to claim 8, characterized in that: In step S1311, the voltage signal may be split by an electronic power divider or an electronic three-way connector.

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