Distributed optical fiber sensing system and method for safely sensing vector acceleration facing robot interaction

Abstract

The invention relates to a distributed optical fiber sensing system and method for safely sensing vector acceleration facing robot interaction. The system comprises a light source, a coupler, a first Mach-Zehnder modulator, an optical circulator, a detection optical fiber, a second Mach-Zehnder modulator and a polarization diversity coherent receiver. The output end of the light source is connected with the input end of the coupler, the output end of the coupler is connected with the input end of the first Mach-Zehnder modulator and the input end of the second Mach-Zehnder modulator, the output end of the first Mach-Zehnder modulator is connected with a first port of the optical circulator, and a second port of the optical circulator is connected with the detection optical fiber. A third port of the optical circulator is connected with the polarization diversity coherent receiver; and the output end of the second Mach-Zehnder modulator is connected with the polarization diversity coherent receiver. According to the invention, the bandwidth of the received signal is greatly reduced, and the spatial domain is broadened after the signal is converted into the time domain, so that excellent spatial resolution and integration are realized, and the sensing ability of the robot is improved.

Description

Technical Field

[0001] This application relates to the fields of optical fiber communication and sensing technology, and more specifically, to a distributed optical fiber sensing system and method for sensing vector acceleration for robot interaction safety. Background Technology

[0002] With the development of the robotics field, the demand for robot interaction safety has received increasing attention. The ability to promptly detect and respond to any harmful or destructive behavior that robots may cause to humans or the environment during production and daily life is a key factor influencing the widespread application of robots in real-world production and daily life. However, limited by single-point sensors, achieving systematic perception of the external environment by robots often requires integrating multiple sensor systems to provide multi-directional sensing information as the basis for feedback control, significantly increasing the complexity of robot sensing functions and deployment costs. Distributed fiber optic sensing technology can effectively solve this problem. By deploying a single optical fiber on a humanoid robot, it systematically senses various locations of the robot in an array. The sensing system is unified, the sensing positions are continuous, and the deployment cost is low. Furthermore, fiber optic sensing also has the characteristics of resistance to electromagnetic interference and strong real-time performance, providing technological support for promoting the practical application of intelligent humanoid robots.

[0003] Distributed fiber optic sensing utilizes backscattered light generated during light propagation in optical fibers. Based on the frequency or phase modulation of different environmental variables (including strain, temperature, vibration, and sound waves) by different scattered light (including Rayleigh scattering, Brillouin scattering, and Raman scattering), and the difference in optical path length of scattered light at different spatial locations within the fiber, distributed environmental sensing along the fiber optic axis is achieved. Compared to traditional single-point sensors, distributed fiber optic sensing technology uses optical fibers as a large-scale sensor array, providing high spatial density sensing information. This significantly improves the sensing capabilities for natural systems such as oceans or geology, building systems such as roads or buildings, and even robots or robotic arms, providing a low-cost and reliable sensing technology for monitoring and analyzing various events. Among the rapidly developing distributed fiber optic sensing technologies, phase-sensitive optical time-domain reflectometry (phi-OTDR) and optical frequency-domain reflectometry (OFDR) are the most mature. Both achieve high-sensitivity vibration or strain detection by measuring the strongest backscattered Rayleigh signal. The former utilizes the time domain to distinguish the vibration location of optical fibers, enabling environmental sensing over a wide range (>50km). Its spatial resolution (the ability to distinguish the spatial scale of events) is typically 1-20m, but this resolution is far from sufficient for applications in robotics sensing. The latter uses a swept-frequency light source to map the frequency and spatial domains, achieving centimeter-level or even millimeter-level spatial resolution. However, it has stringent requirements for the light source, making integration and high efficiency difficult. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing distributed sensing technologies in the field of robotics, such as insufficient spatial resolution and stringent requirements for light sources that make integration difficult. This invention provides a distributed fiber optic sensing system and method for robot interactive safety perception vector acceleration, which meets the spatial resolution requirements of robots and has a simple structure that enables on-chip integration.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A distributed fiber optic sensing system for safe perception of vector acceleration in robot interaction is provided, comprising: a light source, a coupler, a first Mach-Zehnder modulator, an optical circulator, a probe fiber, a second Mach-Zehnder modulator, and a polarization diversity coherent receiver; the output of the light source is connected to the input of the coupler, the output of the coupler is connected to the inputs of the first Mach-Zehnder modulator and the second Mach-Zehnder modulator respectively, the output of the first Mach-Zehnder modulator is connected to the first port of the optical circulator, the second port of the optical circulator is connected to the probe fiber, and the third port of the optical circulator is connected to the polarization diversity coherent receiver; the output of the second Mach-Zehnder modulator is connected to the polarization diversity coherent receiver.

[0006] This invention discloses a distributed fiber optic sensing system for robot interactive safety perception vector acceleration. Based on a phase-sensitive optical time-domain reflectometry (PHI-OTDR) system with dual-frequency comb modulation, it employs a Mach-Zehnder modulator to modulate the probe light and the local oscillator light with dual-frequency comb modulation. This reduces the spectral spacing of the interference result signal between the backscattered Rayleigh light and the local oscillator light to the difference in the comb tooth spacing of the dual-frequency comb, thereby significantly reducing the bandwidth of the received signal. After the signal is converted to the time domain, the spatial domain is broadened, thus achieving superior spatial resolution and integrability, and improving the robot's perception capability.

[0007] Furthermore, a first optical amplifier and a first optical filter are connected between the first Mach-Zehnder modulator and the optical circulator. The output of the first Mach-Zehnder modulator is connected to the input of the first optical amplifier, the output of the first optical amplifier is connected to the input of the first optical filter, and the output of the first optical filter is connected to the first port of the optical circulator.

[0008] Furthermore, a second optical amplifier and a second optical filter are connected between the third port of the optical circulator and the polarization diversity coherent receiver. The third port of the optical circulator is connected to the input of the second optical amplifier, the output of the optical amplifier is connected to the input of the second optical filter, and the output of the second optical filter is connected to the polarization diversity coherent receiver.

[0009] Furthermore, a third optical amplifier and a third optical filter are connected to the second Mach-Zehnder modulator and the polarization diversity coherent receiver. The output of the second Mach-Zehnder modulator is connected to the input of the third optical amplifier, the output of the third optical amplifier is connected to the input of the third optical filter, and the output of the third optical filter is connected to the polarization diversity coherent receiver.

[0010] Further, the output light of the light source is split into two paths after passing through the coupler: one path serves as the probe light, and the other as the local oscillator light. The probe light is modulated into a frequency comb probe light by the first Mach-Zehnder modulator. The frequency comb probe light then passes through the first optical amplifier for optical amplification, the first optical filter for optical filtering, the first port and the second port of the optical circulator before entering the probe fiber. The frequency comb probe light generates a backscattered Rayleigh signal in the probe fiber. The backscattered Rayleigh signal passes through the third port of the optical circulator, the second optical amplifier for optical amplification, and the second optical filter for optical filtering before entering the polarization diversity coherent receiver. The local oscillator light is modulated into a frequency comb local oscillator light by the second Mach-Zehnder modulator. The frequency comb local oscillator light then passes through the third optical amplifier for optical amplification and the third optical filter for optical filtering before entering the polarization diversity coherent receiver. The backscattered Rayleigh light and the frequency comb local oscillator light interfere in the polarization diversity coherent receiver and are converted into an electrical signal.

[0011] Furthermore, the detection fiber is a multi-core fiber, one core of which is used to connect to the second port of the optical circulator, and the remaining cores are connected in series.

[0012] Furthermore, the light source is a narrow-linewidth single-frequency light source. This invention requires only a single-frequency light source and does not rely on a swept-frequency laser with high frequency variation linearity.

[0013] This invention also provides a distributed fiber optic sensing method for safe perception of vector acceleration in robot interaction. Using the distributed fiber optic sensing system described above, a first Mach-Zehnder modulator is used to perform frequency comb modulation on the probe light to obtain a frequency comb probe light. The modulation comb spacing of the probe light by the first Mach-Zehnder modulator is [missing information]. , ,in To detect the length of the optical fiber, To detect the refractive index of the optical fiber, The speed of light in vacuum; the second Mach-Zehnder modulator is used to frequency-comb modulate the local oscillator light to obtain frequency-comb local oscillator light, and the spacing of the modulation comb teeth of the second Mach-Zehnder modulator on the local oscillator light is... ,in Comb tooth spacing difference satisfy , This indicates the number of teeth on the frequency comb; the frequency comb probe light generates backscattered Rayleigh light in the probe fiber, and the backscattered Rayleigh light interferes with the local oscillator probe light in the polarization diversity coherent receiver to obtain a frequency interval of... The electrical signal. Among them, It is equal to the pulse repetition frequency of a traditional phi-OTDR system.

[0014] This invention discloses a distributed fiber optic sensing method for safe sensing vector acceleration in robot interaction. It employs a Mach-Zehnder modulator to perform dual-frequency comb modulation on both the probe light and the local oscillator light, reducing the spectral spacing of the interference signal between the backscattered Rayleigh light and the local oscillator light to the difference in the comb tooth spacing of the dual-frequency comb. Compared with the traditional phi-OTDR, the time domain length of the resulting signal is reduced from... Add to The time domain length is extended This increases the spatial resolution by a factor of two, thus improving it. times.

[0015] Furthermore, it also includes digital signal processing of electrical signals, including low-pass filtering, carrier removal, spatial differential, time differential, phase extraction, and so on.

[0016] Furthermore, the detection fiber is a multi-core fiber connected end-to-end. This multi-core fiber allows for the simultaneous sensing of the corresponding signals of N2 fiber cores in a single interrogation, where N2 is the number of fiber cores connected in series. Utilizing the differences in response to different fiber cores from the same external signal, N2 overdetermined equations are constructed. ,in For the first The angle between the root core and the center line of the probe fiber. For the first Phase measured from the fiber core The two-dimensional vector direction angle of the external signal is obtained by solving the overdetermined system of equations. .

[0017] Furthermore, by converting the phase into strain rate strain rate By performing time differentiation, the acceleration is obtained; where, , The wavelength of light For phase, To detect the refractive index of the optical fiber, This represents the spatial distance in spatial difference operations.

[0018] Compared with the prior art, the beneficial effects of the present invention are: This invention discloses a distributed fiber optic sensing system and method for sensing vector acceleration for robot interaction safety. It employs a Mach-Zehnder modulator to perform dual-frequency comb modulation on the probe light and the local oscillator light, reducing the spectral spacing of the interference signal between the backscattered Rayleigh light and the local oscillator light to the difference in the comb tooth spacing of the dual-frequency comb. This significantly reduces the bandwidth of the received signal. After the signal is converted to the time domain, the spatial domain is broadened, achieving superior spatial resolution and integrability, thus improving the robot's sensing capabilities. By applying multi-core optical fibers and differential operations, high-sensitivity vector acceleration sensing is achieved, providing an excellent solution for robot interaction safety. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a distributed fiber optic sensing system for robot interaction safety perception vector acceleration in Example 1. Figure 2 This is a schematic diagram illustrating the principle of achieving high spatial resolution by modulating a dual-frequency comb with a Mach-Zehnder modulator in Example 3. Figure 3 This is a schematic diagram of multi-core interrogation implemented by series-connected multi-core optical fibers in Example 2. The arrows indicate the direction of signal transmission. Figure 4 This is a schematic diagram of a distributed fiber optic sensing system for robot interaction safety applications.

[0020] In the attached diagram: 1. Light source; 2. Coupler; 3. First Mach-Zehnder modulator; 4. First optical amplifier; 5. First optical filter; 6. Optical circulator; 7. Probe fiber; 8. Second optical amplifier; 9. Second optical filter; 10. Second Mach-Zehnder modulator; 11. Third optical amplifier; 12. Third optical filter; 13. Polarization diversity coherent receiver. Detailed Implementation

[0021] The present invention will be further described below with reference to specific embodiments. The accompanying drawings are for illustrative purposes only, representing schematic diagrams rather than actual physical objects, and should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0022] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0023] Example 1 This embodiment is a first embodiment of a distributed fiber optic sensing system for robot interaction safety perception vector acceleration, such as... Figure 1 As shown, the system includes: a light source 1, a coupler 2, a first Mach-Zehnder modulator 3, a first optical amplifier 4, a first optical filter 5, an optical circulator 6, a probe fiber 7, a second optical amplifier 8, a second optical filter 9, a second Mach-Zehnder modulator 10, a third optical amplifier 11, a third optical filter 12, and a polarization diversity coherent receiver 13. The output of the light source 1 is connected to the input of the coupler 2. The output of the coupler 2 is connected to the inputs of the first Mach-Zehnder modulator 3 and the second Mach-Zehnder modulator 10, respectively. The output of the first Mach-Zehnder modulator 3 is connected to the input of the first optical amplifier 4. The output of the first optical amplifier 4... The first optical amplifier 7 is connected to the input of the first optical filter 5, the output of the first optical filter 5 is connected to the first port of the optical circulator 6, the second port of the optical circulator 6 is connected to the probe fiber 7, the third port of the optical circulator 6 is connected to the input of the second optical amplifier 8, the output of the optical amplifier is connected to the input of the second optical filter 9, and the output of the second optical filter 9 is connected to the polarization diversity coherent receiver 13; the output of the second Mach-Zehnder modulator 10 is connected to the input of the third optical amplifier 11, the output of the third optical amplifier 11 is connected to the input of the third optical filter 12, and the output of the third optical filter 12 is connected to the polarization diversity coherent receiver 13.

[0024] In this embodiment, the light source 1 is a narrow-linewidth single-frequency light source 1. This embodiment only requires the single-frequency light source 1 and does not rely on a swept-frequency laser with high frequency variation linearity.

[0025] Working principle: The output light of light source 1 is split into two paths after passing through coupler 2, one path serving as probe light and the other as local oscillator light. The probe light is modulated into frequency comb probe light by the first Mach-Zehnder modulator 3. The frequency comb probe light passes through the first optical amplifier 4 for optical amplification, the first optical filter 5 for optical filtering, and the first and second ports of the optical circulator 6 before entering the probe fiber 7. The frequency comb probe light generates a backscattered Rayleigh signal in the probe fiber 7. The backscattered Rayleigh signal passes through the third port of the optical circulator 6, the second optical amplifier 8 for optical amplification, and the second optical filter 9 for optical filtering before entering the polarization diversity coherent receiver 13. The local oscillator light is modulated into frequency comb local oscillator light by the second Mach-Zehnder modulator 10. The frequency comb local oscillator light passes through the third optical amplifier 11 for optical amplification and the third optical filter 12 for optical filtering before entering the polarization diversity coherent receiver 13. The backscattered Rayleigh light and the frequency comb local oscillator light interfere in the polarization diversity coherent receiver 13 and are converted into electrical signals. The electrical signals are digitally processed to obtain a high spatial resolution sensing signal along the optical fiber.

[0026] This embodiment presents a distributed fiber optic sensing system for robot interactive safety perception vector acceleration. Based on a phase-sensitive optical time-domain reflectometry (PHI-OTDR) system with dual-frequency comb modulation, it employs a Mach-Zehnder modulator to modulate the probe light and the local oscillator light with dual-frequency comb modulation. This reduces the spectral spacing of the interference result signal between the back Rayleigh scattered light and the local oscillator light to the difference in the comb tooth spacing of the dual-frequency comb, thereby significantly reducing the bandwidth of the received signal. After the signal is converted to the time domain, the spatial domain is broadened, thus achieving superior spatial resolution and integrability, and improving the robot's perception capability.

[0027] This embodiment solves the limitations of traditional distributed fiber optic sensing systems, such as phi-OTDR, which have spatial resolution that is difficult to meet the needs of robot perception scenarios, and OFDR, which relies on a high-quality continuously modulated light source 1 and is difficult to integrate on a chip. This embodiment is based on phi-OTDR technology with dual-frequency comb modulation, and achieves centimeter-level spatial resolution with a phi-OTDR system that only needs to use a single-frequency light source 1. The structure is simple and can be integrated on a chip.

[0028] Example 2 This embodiment is a second embodiment of a distributed optical fiber sensing system for robot interactive safety perception vector acceleration. This embodiment is similar to the first embodiment, except that in this embodiment, the detection optical fiber 7 is a multi-core optical fiber. One core of the multi-core optical fiber is used to connect to the second port of the optical circulator 6, and the remaining cores are connected in series. Figure 3 As shown, the detection fiber 7 is a multi-core fiber connected in series. The multi-core fiber connected in series enables the distributed optical fiber sensing system to simultaneously sense the response signal of the root fiber core in a single query.

[0029] Example 3 This embodiment is an example of a distributed fiber optic sensing method for safety perception vector acceleration in robot interaction. This embodiment uses the distributed fiber optic sensing system provided in Embodiment 1, such as... Figure 2 As shown, the first Mach-Zehnder modulator 3 is used to perform frequency comb modulation on the probe light to obtain frequency comb probe light. The modulation comb spacing of the first Mach-Zehnder modulator 3 on the probe light is... , The pulse repetition frequency, equal to that of a traditional Phi-OTDR system, should satisfy the condition that the period time is greater than the propagation time of light in the fiber under test. ,in To detect the length of fiber optic cable 7, To detect the refractive index of fiber 7, The speed of light in vacuum; the second Mach-Zehnder modulator 10 is used to frequency comb modulate the local oscillator light to obtain frequency combed local oscillator light, and the modulation comb spacing of the second Mach-Zehnder modulator 10 on the local oscillator light is... ,in Furthermore, to avoid signal aliasing, the comb tooth spacing is different. Should meet , This indicates the number of teeth on the frequency comb; the frequency comb probe light generates backscattered Rayleigh light in the probe fiber 7, and the backscattered Rayleigh light interferes with the local oscillator probe light in the polarization diversity coherent receiver 13, resulting in a frequency interval of... The electrical signal is processed digitally, including low-pass filtering, carrier removal, spatial differential, time differential, phase extraction, etc.

[0030] Specifically, taking a probe fiber 7 with a length of less than 200m as an example, to avoid inter-frame pulse aliasing, the probe light repetition frequency needs to be met. The period time is greater than the propagation time of light in the probe fiber 7, that is... ,in To detect the length of fiber 7, The refractive index of the optical fiber. Set to the speed of light in a vacuum. If the frequency band is 500kHz and the number of frequency comb traces is 10,000, then the bandwidth of the modulated frequency comb probe light is 5GHz; the spacing between the comb teeth of the frequency comb modulated by the local oscillator light is... ,in Set to 20Hz; the frequency interval of the resulting signal obtained by interferometric beat frequency analysis of the backscattered Rayleigh light and the local oscillator light is... That is, 20Hz, the signal time domain is from (i.e., 2us) increased to (i.e., 50ms), spatial resolution improved The signal-to-noise ratio is guaranteed by spatial sliding average, and the spatial resolution can reach 2cm.

[0031] Furthermore, the probe fiber 7 is configured as a multi-core fiber connected end-to-end. This multi-core fiber allows for the simultaneous sensing of the corresponding signals from N2 fiber cores in a single interrogation, where N2 is the number of fiber cores connected in series. Utilizing the differences in response to different fiber cores from the same external signal, N2 overdetermined equations are constructed. ,in For the first The angle between the line connecting the core fiber and the center of the probe fiber 7. For the first Phase measured from the fiber core The direction angle of the two-dimensional vector of the external signal can be obtained by solving the overdetermined system of equations using the least squares method. .

[0032] Furthermore, through phase-strain transformation and time differentiation, the response phase is converted into acceleration, yielding a vector acceleration result. The phase is then converted into strain rate. strain rate By performing time differentiation, the acceleration is obtained; where, , The wavelength of light For phase, To detect the refractive index of the optical fiber, This represents the spatial distance in spatial difference operations.

[0033] Existing distributed fiber optic sensing system chips use traditional phi-OTDR systems, which can only achieve meter-level spatial resolution. OFDR systems, capable of achieving high spatial resolution, are limited by the high time-frequency linearity requirements of linear frequency sweep of the light source, making it difficult to meet the on-chip integration needs of humanoid robot sensing scenarios. This invention optimizes the traditional phi-OTDR technology using dual-frequency comb modulation. By separately modulating the probe light and local oscillator light with dual-frequency combs, the spatial resolution performance of the traditional phi-OTDR system is improved from the meter-level (typically 1~20m) limited by probe power and modulation bandwidth to the centimeter-level (2cm). Since the system relies solely on a single-frequency laser light source, current technology can already achieve on-chip integration. Therefore, the dual-frequency comb-modulated phi-OTDR system of this invention is an integrable, high spatial resolution, and high vector acceleration sensing sensitivity distributed fiber optic sensing system, effectively solving the safety issues associated with robot interaction.

[0034] In the specific implementation of the above embodiments, the technical features can be combined in any non-contradictory way. For the sake of brevity, not all possible combinations of the above technical features are described. However, as long as the combination of these technical features is not contradictory, it should be considered to be within the scope of this specification.

[0035] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A distributed fiber optic sensing system for safe perception of vector acceleration in robot interaction, characterized in that, include: The system comprises a light source (1), a coupler (2), a first Mach-Zehnder modulator (3), an optical circulator (6), a probe fiber (7), a second Mach-Zehnder modulator (10), and a polarization diversity coherent receiver (13). The output of the light source (1) is connected to the input of the coupler (2). The output of the coupler (2) is connected to the input of the first Mach-Zehnder modulator (3) and the input of the second Mach-Zehnder modulator (10). The output of the first Mach-Zehnder modulator (3) is connected to the first port of the optical circulator (6). The second port of the optical circulator (6) is connected to the probe fiber (7). The third port of the optical circulator (6) is connected to the polarization diversity coherent receiver (13). The output of the second Mach-Zehnder modulator (10) is connected to the polarization diversity coherent receiver (13).

2. The distributed fiber optic sensing system for robot interaction safety perception vector acceleration according to claim 1, characterized in that, A first optical amplifier (4) and a first optical filter (5) are also connected between the first Mach-Zehnder modulator (3) and the optical circulator (6). The output of the first Mach-Zehnder modulator (3) is connected to the input of the first optical amplifier (4), the output of the first optical amplifier (4) is connected to the input of the first optical filter (5), and the output of the first optical filter (5) is connected to the first port of the optical circulator (6).

3. The distributed fiber optic sensing system for robot interaction safety perception vector acceleration according to claim 2, characterized in that, A second optical amplifier (8) and a second optical filter (9) are also connected between the third port of the optical circulator (6) and the polarization diversity coherent receiver (13). The third port of the optical circulator (6) is connected to the input of the second optical amplifier (8), the output of the optical amplifier is connected to the input of the second optical filter (9), and the output of the second optical filter (9) is connected to the polarization diversity coherent receiver (13).

4. The distributed fiber optic sensing system for robot interaction safety perception vector acceleration according to claim 3, characterized in that, A third optical amplifier (11) and a third optical filter (12) are also connected to the second Mach-Zehnder modulator (10) and the polarization diversity coherent receiver (13). The output of the second Mach-Zehnder modulator (10) is connected to the input of the third optical amplifier (11), the output of the third optical amplifier (11) is connected to the input of the third optical filter (12), and the output of the third optical filter (12) is connected to the polarization diversity coherent receiver (13).

5. The distributed fiber optic sensing system for robot interaction safety perception vector acceleration according to claim 4, characterized in that, The output light from the light source (1) is split into two paths after passing through the coupler (2), one path serving as the probe light and the other as the local oscillator light. The probe light is modulated into a frequency comb probe light by the first Mach-Zehnder modulator (3). The frequency comb probe light passes through the first optical amplifier (4) for optical amplification, the first optical filter (5) for optical filtering, and the first and second ports of the optical circulator (6) in sequence before entering the probe fiber (7). The frequency comb probe light generates a backscattered Rayleigh signal in the probe fiber (7). The backscattered Rayleigh signal passes through the optical circulator. The optical amplification of the second optical amplifier (8) and the optical filtering of the second optical filter (9) are passed through the third port of the shaper (6) and enter the polarization diversity coherent receiver (13); the local oscillator light is modulated into a frequency comb local oscillator light by the second Mach-Zehnder modulator (10), and the frequency comb local oscillator light is sequentially passed through the optical amplification of the third optical amplifier (11) and the optical filtering of the third optical filter (12) before entering the polarization diversity coherent receiver (13); the back Rayleigh scattered light and the frequency comb local oscillator light interfere in the polarization diversity coherent receiver (13) and are converted into electrical signals.

6. The distributed fiber optic sensing system for robot interactive safety perception vector acceleration according to any one of claims 1 to 5, characterized in that, The detection fiber (7) is a multi-core fiber, one of the cores of which is used to connect to the second port of the optical circulator (6), and the remaining cores are connected in series.

7. The distributed fiber optic sensing system for robot interaction safety perception vector acceleration according to claim 6, characterized in that, The light source (1) is a narrow linewidth single-frequency light source (1).

8. A distributed fiber optic sensing method for vector acceleration for safety perception in robot interaction, characterized in that, The distributed optical fiber sensing system according to any one of claims 1 to 7 is used, wherein the first Mach-Zehnder modulator (3) is used to perform frequency comb modulation on the probe light to obtain frequency comb probe light, and the modulation comb spacing of the probe light by the first Mach-Zehnder modulator (3) is as follows: , ,in To detect the length of the optical fiber (7), To detect the refractive index of the optical fiber (7), The speed of light in vacuum; the second Mach-Zehnder modulator (10) is used to perform frequency comb modulation on the local oscillator light to obtain frequency comb local oscillator light, and the spacing of the modulation comb teeth of the second Mach-Zehnder modulator (10) on the local oscillator light is... ,in Comb tooth spacing difference satisfy , The number of teeth in the frequency comb is indicated; the frequency comb probe light generates backscattered Rayleigh light in the probe fiber (7), and the backscattered Rayleigh light interferes with the local oscillator probe light in the polarization diversity coherent receiver (13) to obtain a frequency interval of . The electrical signal.

9. The distributed fiber optic sensing method for robot interaction safety perception vector acceleration according to claim 8, characterized in that, The detection fiber (7) is a multi-core fiber connected end-to-end. Through the multi-core fiber connected in series, the corresponding signals of N2 fiber cores can be sensed simultaneously in a single interrogation, where N2 is the number of fiber cores connected in series. By utilizing the response differences of the same external signal to different fiber cores, N2 overdetermined equations are constructed. ,in For the first The angle between the line connecting the root core and the center of the probe fiber (7), For the first Phase measured from the fiber core The two-dimensional vector direction angle of the external signal is obtained by solving the overdetermined system of equations. .

10. The distributed fiber optic sensing method for robot interaction safety perception vector acceleration according to claim 8, characterized in that, By converting phase to strain rate strain rate By performing time differentiation, the acceleration is obtained; where, , The wavelength of light For phase, To detect the refractive index of the optical fiber, This represents the spatial distance in spatial difference operations.

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