A multi-directional velocity sensing micro multi-core fiber probe and a multi-directional velocity measuring device

Abstract

The application provides a multi-directional velocity sensing micro multi-core optical fiber probe and a multi-directional velocity measuring device, and belongs to the technical field of laser detection and velocity measurement. The device comprises a continuous light source, a first optical splitter, a pulsed light source, a modulator, a first optical wavelength division multiplexer, n optical circulators, a multi-core optical fiber fan-in and fan-out device, a probe, a second optical wavelength division multiplexer, an axial photoelectric detector, a second optical splitter, and m radial photoelectric detectors. By combining the cores at different positions in the probe, multiple velocity information acquisition channels can be formed. The probe is composed of m radial core groups, the total number of cores is n, the m straight lines where the radial core groups are located intersect the axis of the No. 1 core, the No. 1 core is used for axial sensing, the radial core groups are used for axial sensing, the axial photoelectric detector and the radial photoelectric detector are used for outputting signals to an upper computer, and the upper computer calculates the axial and radial velocities according to the calculation requirements. The application realizes the synchronous velocity measurement in multiple directions.

Description

Technical Field

[0001] This invention relates to the field of laser detection and velocity measurement technology, and in particular to a miniature multi-core fiber optic probe and a multi-directional velocity measurement device for multi-directional velocity sensing. Background Technology

[0002] Optical measurement is an advanced detection method that combines precise and sensitive optical technology with modern photoelectric detection technology. However, traditional optical probes face problems such as complex probe structure, large size, and high cost. The reasons are as follows: First, the probe often contains many components, such as optical emitting modules, optical receiving modules, mechanical rotating motors, and other modules; Second, the strict coupling and matching between multiple discrete optical devices and optical channels inside the probe requires a lot of precise and time-consuming assembly and adjustment work. For example, the spatial optical channel formed between the optical emitting module and the optical receiving module requires a lot of precise and time-consuming setup and adjustment to improve the optical coupling efficiency.

[0003] Laser velocimetry is a relatively accurate method of speed measurement. It features a stable light source and minimal incident signal error. However, building a multidimensional laser velocimetry device directly using optical components requires installing multiple devices to complete speed measurements along different axes. Therefore, when multidimensional speed measurement is needed, the installation process is relatively complex, occupies too much space, and is not convenient or quick. Summary of the Invention

[0004] In view of this, the present invention provides a miniature multi-core fiber optic probe and a multi-directional velocity measurement device for multi-directional velocity sensing, which can perform synchronous multi-dimensional velocity measurement. It has the characteristics of simple structure, small size, small space occupation, and convenient use.

[0005] The technical solution adopted by the embodiments of the present invention to solve its technical problem is as follows:

[0006] A multi-directional velocity sensing miniature multi-core fiber optic probe includes: a continuous light source (1), a first optical splitter (2), a pulsed light source (3), a modulator (4), a first optical wavelength division multiplexer (5), n optical circulators [6-1 to 6-n], a multi-core fiber fan-in fan-out unit (7), a probe (8), a second optical wavelength division multiplexer (9), an axial photodetector (10), a second optical splitter (11), and m radial photodetectors [12-1 to 12-m].

[0007] The probe (8) consists of m radial fiber cores arranged in a straight line [a1~a1~a2~a3~a4~a5~a6~a7~a8~a9~a1 ... m The radial core groups [a1~a1~a2] consist of n fibers and have a total number of n cores. m The intersection point of the m straight lines [a1~am] is located on the axis of fiber core 1, where fiber core 1 is the radial fiber core group [a1~am]. mThe common core of the radial core group [a1~a1] is also used for axial sensing. m Each of the fiber cores in the array has the capability to transmit and receive optical signals, and the radial photodetectors [12-1 to 12-m] are used to receive signals from the corresponding numbered radial fiber core groups [a1 to a2]. m The reflected light signal;

[0008] The continuous light source (1) is connected to the input end of the optical splitter (2). The optical splitter (2) has output ports [2-1 to 2-n]. The output port (2-1) of the optical splitter (2) is connected to the first output end of the first optical wavelength division multiplexer (5). The output end of the first optical wavelength division multiplexer (5) is connected to the input port (7-1) of the multi-core fiber fan-in / fan-out unit 7. The output ports [2-2 to 2-n] of the optical splitter (2) are connected to the optical circulator in numerical order. The common ends of the optical circulators [6-2 to 6-n] are connected to the input ports [7-2 to 7-n] of the multi-core fiber fan-in fan-out unit 7 in numerical order; the output port of the multi-core fiber fan-in fan-out unit 7 is connected to the probe (8), so that the optical splitter (2), the optical circulators [6-1 to 6-n], the multi-core fiber fan-in fan-out unit 7 and the n fiber cores establish optical paths accordingly, wherein the first fiber core is connected to the input port (7-1);

[0009] The pulsed light source (3), the modulator (4), and the second input terminal of the first optical wavelength division multiplexer (5) are connected in sequence;

[0010] The receiving end of the optical circulator (6-1) is connected to the input end of the second optical wavelength division multiplexer (9). The first output end of the second optical wavelength division multiplexer (9) is connected to the axial photodetector (10), and the output type is a pulse signal. The second output end of the second optical wavelength division multiplexer (9) is connected to the input end of the second optical splitter (11), and the output type is a continuous signal. The m output ends of the second optical splitter (11) are respectively connected to the m radial photodetectors [12-1~12-m]. The receiving ends of the optical circulator [6-2~6-n] are connected according to the radial fiber core group [a1~a2-n]. m The numbers are connected to the corresponding radial photodetectors [12-1 to 12-m];

[0011] The axial photodetector (10) and the radial photodetector [12-1~12-m] are used to connect to the host computer and output electrical signals to the host computer. The signal output by the axial photodetector (10) is used to calculate the axial velocity, and the signal output by the radial photodetector [12-1~12-m] is used to calculate the velocity in the direction of the straight line [a1~am].

[0012] During the optical signal transmission process, the continuous light source (1) outputs a continuous laser signal, which is split into n beams by the first optical splitter (2). The first beam and the pulsed laser signal of the pulsed light source (3) are processed by the first optical wavelength division multiplexer (5) and then output into the optical circulator (6-1). The second to n beams directly enter the corresponding numbered optical circulators [6-2 to 6-n]. The optical signals output from the common ends of each of the optical circulators [6-1 to 6-n] are input to the corresponding fiber cores of the probe (8) through the multi-core fiber fan-in and fan-out device 7.

[0013] During the optical signal reception process, each fiber core of the probe (8) receives the reflected optical signal. The reflected optical signals received by the fiber cores 2 to n pass sequentially through the multi-core fiber fan-in / fan-out unit 7, the corresponding numbered optical circulators [6-2 to 6-n], and arrive at the corresponding numbered radial photodetectors [12-1 to 12-m]. The reflected optical signal of the fiber core 1 passes through the multi-core fiber fan-in / fan-out unit 7, the optical circulator (6-1), and arrives at the second optical wavelength division multiplexer (9). The second optical wavelength division multiplexer (9) outputs the continuous signal obtained by separating the reflected optical signal to the second optical splitter (11). The second optical splitter (11) splits the signal into m beams and inputs them to the radial photodetectors [12-1 to 12-m]. The second optical wavelength division multiplexer (9) outputs the pulse signal obtained by separating the reflected optical signal to the axial photodetector (10).

[0014] Preferably, the probe consists of n fiber cores, a cladding layer providing fiber core insertion, a coating layer covering the outer surface of the cladding layer, and a protective shell mounted on the outer surface of the coating layer.

[0015] Preferably, the wavelengths of the continuous light source (1) and the pulsed light source (3) are different.

[0016] Preferably, the spacing between the individual cores within the same radial core group is the same.

[0017] Preferably, the protective shell is made of a high-hardness material.

[0018] Preferably, the connections between the various components in the miniature multi-core fiber optic probe are all made using fiber optic connections.

[0019] The present invention also provides a multi-directional speed measurement device, comprising the aforementioned multi-directional speed sensing miniature multi-core fiber optic probe and a host computer:

[0020] The axial photodetector (10) and radial photodetectors [12-1 to 12-m] in the miniature multi-core fiber optic probe are used to output signals to the host computer;

[0021] Under the condition of axial velocity calculation, the host computer is connected to the axial photodetector (10) and receives signals. The host computer calculates the axial velocity based on the signal output by the axial photodetector (10).

[0022] Under the condition of radial velocity calculation, the host computer is connected to at least one axial photodetector corresponding to the required direction among the m radial photodetectors [12-1 to 12-m] and receives signals. The host computer calculates the velocity in the required direction based on the signals output by the radial photodetectors [12-1 to 12-m].

[0023] Under the condition of axial and radial velocity calculation requirements, the host computer is connected to the axial photodetector (10) and the corresponding radial photodetector.

[0024] As can be seen from the above technical solution, the multi-directional speed sensing miniature multi-core fiber optic probe and multi-directional speed measurement device provided in the embodiments of the present invention are composed of a continuous light source, a first optical splitter, a pulse light source, a modulator, a first optical wavelength division multiplexer, n optical circulators, a multi-core fiber fan-in fan-out unit, a probe, a second optical wavelength division multiplexer, an axial photodetector, a second optical splitter, and m radial photodetectors. The probe is composed of m radial fiber core groups arranged in a straight line, with a total number of n fiber cores. The intersection point of the m straight lines where the radial fiber core groups are located is located on the axis of fiber core No. 1. Fiber core No. 1 is both a common fiber core of the radial fiber core groups and is used for axial sensing. The radial fiber core groups are used for axial sensing. The axial photodetector and the radial photodetector are used to output signals to the host computer. The host computer performs axial and radial speed calculations according to the calculation requirements. The present invention realizes synchronous speed measurement in multiple directions and can perform synchronous multi-dimensional speed measurement. It has the characteristics of simple structure, small size, small space occupation, and convenient use. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of the multi-directional velocity sensing miniature multi-core fiber optic probe of the present invention.

[0026] Figure 2 This is a schematic diagram of the radial fiber core assembly in the probe of the present invention.

[0027] Figure 3 This is a schematic diagram of the probe cross-section of the present invention.

[0028] In the diagram: 1. Continuous light source; 2. First optical splitter; 3. Pulse light source; 4. Modulator; 5. First optical wavelength division multiplexer; 6-1 to 6-9. Optical circulator; 7. Multi-core fiber fan-in / fan-out; 8. Probe; 9. Second optical wavelength division multiplexer; 10. Axial photodetector; 11. Second optical splitter; 12-1 to 12-4. Radial photodetector; 8-1. Fiber core; 8-2. Cladding layer; 8-3. Coating layer; 8-4. Protective shell. Detailed Implementation

[0029] The technical solution and effects of the present invention will be further described in detail below with reference to the accompanying drawings.

[0030] This invention provides a miniature multi-core fiber optic probe for multi-directional velocity sensing and a multi-directional velocity measurement device, such as... Figure 1 As shown, the miniature multi-core fiber optic probe consists of a continuous light source (1), a first optical splitter (2), a pulsed light source (3), a modulator (4), a first optical wavelength division multiplexer (5), n optical circulators [6-1 to 6-n], a multi-core fiber fan-in / fan-out unit (7), a probe (8), a second optical wavelength division multiplexer (9), an axial photodetector (10), a second optical splitter (11), and m radial photodetectors [12-1 to 12-m]. All components in the miniature multi-core fiber optic probe are connected using optical fibers. The optical circulators [6-1 to 6-n] refer to optical circulators (6-1), (6-2), ..., (6-n), and the radial photodetectors [12-1 to 12-m] refer to radial photodetectors (12-1), (12-2), ..., (12-n).

[0031] like Figure 3 As shown, the probe (8) consists of n fiber cores 8-1, a cladding 8-2, a coating layer 8-3, and a protective shell 8-4. The coating layer 8-3 wraps around the outer surface of the cladding 8-2, and the protective shell 8-4 is mounted on the outer surface of the coating layer. The protective shell is made of a high-hardness material, and the coating layer and the protective shell are fixed with heat-cured epoxy resin. The probe (8) uses multi-core optical fiber, which is a new type of microstructure optical fiber. Its characteristic is that there are multiple fiber cores in its cladding, and its uniformity and neatness of arrangement are higher than those of optical fiber arrays, ensuring measurement accuracy. The probe (8) simultaneously transmits and receives optical signals. By combining the fiber cores at different positions in the probe, multiple speed information acquisition channels can be formed.

[0032] Structurally, the miniature multi-core fiber optic probe possesses both axial and radial detection capabilities. Axial detection utilizes the No. 1 fiber core located at the center, while radial detection in a single direction utilizes a group of radially linearly arranged fiber cores. Radial detection in multiple directions utilizes multiple groups of radially linearly arranged fiber cores. In this invention, the probe (8) consists of m radially arranged fiber core groups [a1~a1~a2~a3~a4~a5~a6~a7~a8~a9~a1 ... m The composition and total number of fiber cores are n. The positions of the fiber cores are fixed by the fiber core intercalation provided in cladding 8-2, so that they are arranged in a star-shaped radial array, satisfying the requirement that they are radially arranged in a straight line. The radial fiber core groups [a1~a2] are... m The intersection point of the m straight lines [a1~am] containing the core is located on the axis of fiber core 1, where fiber core 1 is both the radial fiber core group [a1~a... m The common core of the fiber is also used for axial sensing, and the radial core assembly [a1~a] is used for radial sensing. m Each fiber core in the array has the capability to transmit and receive optical signals. Radial photodetectors [12-1 to 12-m] are used to receive signals from the corresponding numbered radial fiber core groups [a1 to a2]. m The reflected light signal; a radial fiber core group corresponds to a velocity information acquisition channel in one direction, and the spacing between each fiber core in the same radial fiber core group is the same to avoid errors;

[0033] A continuous light source (1) is connected to the input end of an optical splitter (2). The optical splitter (2) has output ports [2-1 to 2-n]. The output port (2-1) of the optical splitter (2) is connected to the first output end of a first optical wavelength division multiplexer (5). The output end of the first optical wavelength division multiplexer (5) is connected to the input port (7-1) of a multi-core fiber fan-in / fan-out unit 7. The output ports [2-2 to 2-n] of the optical splitter (2) are connected to optical rings in numerical order. The transmitter of the optical splitter [6-2~6-n] and the common end of the optical circulator [6-2~6-n] are connected to the input ports [72~7n] of the multi-core fiber fan-in fan-out unit 7 in the order of their numbers. The output port of the multi-core fiber fan-in fan-out unit 7 is connected to the probe (8), so that the optical splitter (2), the optical circulator [6-1~6-n], the multi-core fiber fan-in fan-out unit 7 and the n fiber cores establish optical paths, wherein the first fiber core is connected to the input port (7-1).

[0034] The second input terminals of the pulse light source (3), modulator (4), and first optical wavelength division multiplexer (5) are connected in sequence;

[0035] The receiving end of the optical circulator (61) is connected to the input end of the second optical wavelength division multiplexer (9). The first output end of the second optical wavelength division multiplexer (9) is connected to the axial photodetector (10), and the output type is a pulse signal. The second output end of the second optical wavelength division multiplexer (9) is connected to the input end of the second optical splitter (11), and the output type is a continuous signal. The m output ends of the second optical splitter (11) are respectively connected to m radial photodetectors [121~12]. m The receiving end of the optical circulator [6-2~6-n] is arranged according to the radial fiber core group [a1~a] m The numbers are connected to the corresponding radial photodetectors [12-1 to 12-m].

[0036] The axial photodetector (10) and the radial photodetector [12-1~12-m] are used to connect to the host computer and output electrical signals to the host computer. The signal output by the axial photodetector (10) is used to calculate the axial velocity, and the signal output by the radial photodetector [12-1~12-m] is used to calculate the straight line [a1~a m ] velocity in the direction;

[0037] During the optical signal transmission process, the continuous light source (1) outputs a continuous laser signal, which is split into n beams by the first optical splitter (2). The first beam and the pulsed laser signal of the pulsed light source (3) are processed by the first optical wavelength division multiplexer (5) and then output into the optical circulator (61). The second to n beams directly enter the corresponding numbered optical circulators [6-2 to 6-n]. The optical signals output from each common end of the optical circulators [6-1 to 6-n] are input to each fiber core of the probe (8) through the multi-core fiber fan-in fan-out device (7).

[0038] During the optical signal reception process, each fiber core of the probe (8) receives the reflected optical signal. The reflected optical signals received by fiber cores 2 to n pass through the multi-core fiber fan-in fan-out unit 7, the corresponding numbered optical circulator [6-2 to 6-n], and arrive at the corresponding numbered radial photodetector [12-1 to 12-m]. The reflected optical signal of fiber core 1 passes through the multi-core fiber fan-in fan-out unit 7, the optical circulator (61), and arrives at the second optical wavelength division multiplexer (9). The second optical wavelength division multiplexer (9) outputs the continuous signal obtained by separating the reflected optical signal to the second optical splitter (11). The second optical splitter (11) splits the signal into m beams and inputs them to the radial photodetector [12-1 to 12-m]. The second optical wavelength division multiplexer (9) outputs the pulse signal obtained by separating the reflected optical signal to the axial photodetector (10).

[0039] The following examples illustrate this point; please refer to them as well. Figure 1 and Figure 2Taking a total number of fiber cores n=9 and the number of radial fiber core groups m=4 as an example, we use a, b, c, w to replace [a1~a4] as the numbering of the radial fiber core groups. The lines [a1~a4] are named using the a-axis, b-axis, c-axis, and w-axis, respectively. The fiber core numbers are as follows: Figure 2 As shown. The optical signal output from the continuous light source 1 is split into nine optical signals after entering the optical splitter 2. The optical signal output from the pulsed light source 3 is processed by the modulator 4, and then multiplexed with the first optical signal output from the optical splitter 2 through the optical wavelength division multiplexer 5. Subsequently, the nine optical signals are input to the nine ports (7-1 to 7-9) of the multi-core fiber fan-in fan-out unit 7 through nine optical circulators (6-1 to 6-9), and finally enter the multi-core fiber probe 8 and are emitted to the object under test.

[0040] The optical signal reflecting the load speed information from the object under test is collected by the multi-core fiber optic probe 8. This optical signal returns to the nine optical circulators (6-1 to 6-9) through the nine ports (7-1 to 7-9) of the multi-core fiber optic fan-in / fan-out unit 7. The optical signal from the optical circulator 6-1 is input to the optical wavelength division multiplexer 9, which separates the reflected continuous optical signal from the pulsed optical signal. The pulsed optical signal is input to the photodetector 10, while the continuous optical signal is input to the optical splitter 11. The optical splitter 11 outputs four signals to the photodetectors 12-1 to 12-4. The other eight optical circulators (6-2 to 6-9) output the optical signals to the photodetectors 12-1 to 12-4.

[0041] Here, the wavelengths of the continuous light source (1) and the pulsed light source (3) are different, so that the axial and radial velocity measurements do not interfere with each other and the signals are accurately separated.

[0042] It can be seen that fiber core No. 1 can be directly used for axial velocity measurement. The axial photodetector (10) outputs an electrical signal to the host computer to calculate the velocity component signal V of the moving object. z The three optical signals 7-1 (continuous light), 7-2, and 7-6 enter the same photodetector 12-1. Therefore, fiber cores 1, 2, and 6 belong to radial fiber core group a, corresponding to the velocity measurement along axis a. The radial photodetector (12-1) outputs an electrical signal to the host computer to calculate the velocity component signal V of the moving object. a The three optical signals 7-1 (continuous light), 7-3, and 7-7 enter the same photodetector 12-2. Therefore, fiber cores 1, 3, and 7 belong to radial fiber core group b, corresponding to the velocity measurement along the b-axis. The radial photodetector (12-2) outputs an electrical signal to the host computer to calculate the velocity component signal V of the moving object. bThe three optical signals 7-1 (continuous light), 7-4, and 7-8 enter the same photodetector 12-3. Therefore, fiber cores 1, 4, and 8 belong to radial fiber core group c, corresponding to the c-axis velocity measurement. The radial photodetector (12-3) outputs an electrical signal to the host computer to calculate the velocity component signal V of the moving object. c The three optical signals 7-1 (continuous light section), 7-5, and 7-9 enter the same photodetector 12-4. Therefore, fiber cores 1, 5, and 9 belong to the radial fiber core group w, corresponding to the w-axis velocity measurement. The radial photodetector (12-4) outputs an electrical signal to the host computer to calculate the velocity component signal V of the moving object. w Each radial fiber core group is used for one-dimensional velocity. Accordingly, by arbitrarily selecting two or more of the signals from the axial photodetector (10), radial photodetector (12-2), radial photodetector (12-3), and radial photodetector (12-4), the host computer can perform synchronous calculation of multi-directional velocity.

[0043] In the radial direction, two linear arrays (one-dimensional velocity measurement channels) on different axes can be combined to form a two-dimensional velocity measurement channel, depending on the actual needs. For example, combining the a-axis and the b-axis can measure the velocity component V of a moving object. a With V b Then via V a With V b Calculate the radial resultant velocity V of the object.

[0044] It should be noted that the number and arrangement of fiber cores may vary in different multi-core optical fibers. Therefore, the number of axes, the relative positions between axes, the number of fiber cores on the axes, and the number of one-dimensional velocity measurement channels are not limited to the above implementation examples.

[0045] The probe has a compact structure and small size, and can simultaneously acquire multi-directional velocity information. The protective shell isolates the probe from external dust, water vapor and other factors that affect its service life, ensuring long-term reliability.

[0046] Furthermore, the present invention also provides a multi-directional speed measuring device, including... Figure 1 The diagram shows a multi-directional velocity sensing miniature multi-core fiber optic probe and a host computer, wherein:

[0047] The axial photodetector (10) and radial photodetector [12-1~12-m] in the miniature multi-core fiber optic probe are used to output signals to the host computer;

[0048] Under the condition of axial velocity calculation, the host computer is connected to the axial photodetector (10) and receives signals. The host computer calculates the axial velocity based on the signal output by the axial photodetector (10).

[0049] Under the condition of radial velocity calculation, the host computer is connected to at least one axial photodetector corresponding to the required direction among m radial photodetectors [12-1 to 12-m] and receives signals. The host computer calculates the velocity in the required direction based on the signals output by the radial photodetectors [12-1 to 12-m].

[0050] Under the condition of axial and radial velocity calculation requirements, the host computer is connected to the axial photodetector (10) and the corresponding radial photodetector.

[0051] Can be referred to together Figure 1 and Figure 2 The radial photodetector (12-1) collects the optical signals from each fiber core along axis a. The host computer can calculate the component velocity signal V of the moving object based on the output signal of the radial photodetector (12-1). a The radial photodetector (12-2) collects the optical signals from each fiber core along axis b. The host computer can calculate the velocity component V of the moving object based on the output signal of the radial photodetector (12-2). b The radial photodetector (12-3) collects the optical signals from each fiber core along axis c. The host computer can calculate the velocity component V of the moving object based on the output signal of the radial photodetector (12-3). c The radial photodetector (12-4) collects the optical signals from each fiber core along axis w. The host computer can calculate the velocity component V of the moving object based on the output signal of the radial photodetector (12-4). w The host computer calculates the component velocity signal V of the moving object based on the signal provided by the axial photoelectric detector (10). z .

[0052] In the radial direction, the host computer can combine linear arrays (one-dimensional velocity information acquisition channels) on two different axes as needed to form a two-dimensional velocity measurement. For example, by combining the a-axis and the b-axis, the velocity information components Va and Vb of the moving object can be acquired, and then the radial resultant velocity V of the object can be calculated using Va and Vb.

[0053] Combining radial and axial axes allows for two-dimensional or three-dimensional velocity measurements. For example, combining the a-axis, b-axis, and z-axis allows for velocity calculations based on V... a V b V z The three-dimensional radial resultant velocity V is obtained.

[0054] Therefore, this invention enables synchronous speed measurement in multiple directions, allowing for synchronous multidimensional speed measurement. It features a simple structure, small size, minimal space requirements, and ease of use.

[0055] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A multi-directional speed measuring device, characterized in that, Includes miniature multi-core fiber optic probes and host computer: The multi-directional velocity sensing miniature multi-core fiber optic probe includes: a continuous light source (1), a first optical splitter, a pulsed light source (3), a modulator (4), a first optical wavelength division multiplexer (5), n optical circulators [6-1~6-n], a multi-core fiber fan-in fan-out unit (7), a probe (8), a second optical wavelength division multiplexer (9), an axial photodetector, a second optical splitter (11), and m radial photodetectors [12-1~12-m]. The probe (8) consists of m radial fiber cores arranged in a straight line [a1~a2]. m The radial core group [a1~a1] consists of n fibers and has a total number of n cores. m The intersection point of the m straight lines [a1~am] is located on the axis of fiber core 1, where fiber core 1 is the radial fiber core group [a1~am]. m The common core of the radial core group [a1~a1] is also used for axial sensing. m Each of the fiber cores in the array has the capability to transmit and receive optical signals, and the radial photodetectors [12-1~12-m] are used to receive signals from the corresponding numbered radial fiber core groups [a1~a2]. m The reflected light signal; The continuous light source (1) is connected to the input end of the optical splitter. The optical splitter has output ports [2-1~2-n]. The output port (2-1) of the optical splitter is connected to the first output end of the first optical wavelength division multiplexer (5). The output end of the first optical wavelength division multiplexer (5) is connected to the input port (7-1) of the multi-core fiber fan-in / fan-out unit 7. The output ports [2-2~2-n] of the optical splitter are connected to the optical circulator [6-2~2-2-n] in numerical order. The common ends of the optical circulators [6-2~6-n] are connected to the input ports [7-2~7-n] of the multi-core fiber fan-in fan-out unit 7 in numerical order; the output port of the multi-core fiber fan-in fan-out unit 7 is connected to the probe (8), so that the optical splitter, the optical circulators [6-1~6-n], the multi-core fiber fan-in fan-out unit 7 and the n fiber cores establish optical paths accordingly, wherein the first fiber core is connected to the input port (7-1); The pulsed light source (3), the modulator (4), and the second input terminal of the first optical wavelength division multiplexer (5) are connected in sequence; The receiving end of the optical circulator (6-1) is connected to the input end of the second optical wavelength division multiplexer (9). The first output end of the second optical wavelength division multiplexer (9) is connected to the axial photodetector, and the output type is pulse signal. The second output end of the second optical wavelength division multiplexer (9) is connected to the input end of the second optical splitter (11), and the output type is continuous signal. The m output ends of the second optical splitter (11) are respectively connected to the m radial photodetectors [12-1~12-m]. The receiving end of the optical circulator [6-2~6-n] is connected according to the radial fiber core group [a1~a2]. m The numbers are connected to the corresponding radial photodetectors [12-1~12-m]; The axial photodetector and the radial photodetector [12-1~12-m] are used to connect to the host computer and output electrical signals to the host computer. The signal output by the axial photodetector is used to calculate the axial velocity, and the signal output by the radial photodetector [12-1~12-m] is used to calculate the velocity in the direction of the straight line [a1~am]. During the optical signal transmission process, the continuous light source (1) outputs a continuous laser signal, which is split into n beams by the first optical splitter. The first beam and the pulsed laser signal of the pulsed light source (3) are processed by the first optical wavelength division multiplexer (5) and then output into the optical circulator (6-1). The second to n beams directly enter the corresponding numbered optical circulators [6-2 to 6-n]. The optical signals output from each common end of the optical circulators [6-1 to 6-n] are input to each fiber core of the probe (8) through the multi-core fiber fan-in and fan-out device (7). During the optical signal reception process, each fiber core of the probe (8) receives reflected optical signals. The reflected optical signals received by fiber cores 2 to n pass sequentially through the multi-core fiber fan-in / fan-out unit 7, the corresponding numbered optical circulator [6-2 to 6-n], and arrive at the corresponding numbered radial photodetector [12-1 to 12-m]. The reflected optical signal of fiber core 1 passes through the multi-core fiber fan-in / fan-out unit 7, the optical circulator (6-1), and arrives at the second optical wavelength division multiplexer (9). The second optical wavelength division multiplexer (9) outputs the continuous signal obtained by separating the reflected optical signal to the second optical splitter (11). The second optical splitter (11) splits the signal into m beams and inputs them to the radial photodetector [12-1 to 12-m]. The second optical wavelength division multiplexer (9) outputs the pulse signal obtained by separating the reflected optical signal to the axial photodetector. The axial photodetector and radial photodetector [12-1~12-m] in the miniature multi-core fiber optic probe are used to output signals to the host computer. Under the condition of axial velocity calculation, the host computer is connected to the axial photodetector and receives signals through fiber optic core 1. The host computer calculates the axial velocity V based on the signal output by the axial photodetector. z ; Under the condition of radial velocity calculation, the host computer is connected to at least one axial photodetector corresponding to the required direction among the m radial photodetectors [12-1~12-m] and receives signals. The host computer calculates the velocity in the required direction based on the signal output by the radial photodetectors [12-1~12-m], which is the velocity on the straight line where each radial fiber core group is located. Under the requirement of calculating axial and radial velocities, the host computer is connected to the axial photodetector and the corresponding radial photodetector, and the velocities on the straight lines where each radial fiber core group is located are compared with the axial velocity V. z The resultant velocity is the radial velocity V.

2. The multi-directional speed measuring device as described in claim 1, characterized in that, The probe consists of n fiber cores, a cladding layer providing fiber core insertion, a coating layer covering the outer surface of the cladding layer, and a protective shell mounted on the outer surface of the coating layer.

3. The multi-directional speed measuring device as described in claim 2, characterized in that, The wavelengths of the continuous light source (1) and the pulsed light source (3) are different.

4. The multi-directional speed measuring device as described in claim 3, characterized in that, The spacing between the individual cores within the same radial core group is the same.

5. The multi-directional speed measuring device as described in claim 4, characterized in that, The protective shell is made of a high-hardness material.

6. The multi-directional speed measuring device as described in claim 5, characterized in that, The connections between the various components in the miniature multi-core fiber optic probe are all made using fiber optic connections.

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