Sapphire fiber F-P double-sensing microprobe based on rotary scanning and measuring method

Abstract

This application discloses a sapphire fiber optic F-P dual-sensor micro probe based on rotational scanning and a measurement method. The probe transforms the traditional "multi-point spatial measurement" into a "reference measurement + single-point rotational scanning measurement" method by setting a reference measurement channel and a rotational scanning measurement channel. While ensuring the miniaturization of the probe (the diameter of the spherical probe at the front end is about 3mm) and high temperature adaptability, it realizes continuous spatial distribution measurement of the measured area.

Description

Technical Field

[0001] This application belongs to the field of fiber optic sensor technology, specifically relating to a sapphire fiber optic FP dual-sensor micro probe and measurement method based on rotational scanning, which is suitable for high spatial resolution measurement of parameters of high-temperature complex flow fields or structural surfaces. Background Technology

[0002] In aero-engines, gas turbines, compressors, turbomachinery, and various high-temperature aerodynamic experimental environments, flow field parameters often exhibit significant spatial non-uniformity and temporal unsteadiness. For example, in the blade wake region, boundary layer region, near shock waves, and in local high-gradient flow regions, parameters such as pressure, strain, and temperature change rapidly with time and spatial location. To study these complex physical phenomena, it is usually necessary to use miniature sensor probes to perform high-resolution measurements of local areas.

[0003] Traditional flow field measurement probes often employ porous structures, fixed multi-point structures, or combinations of multiple discrete sensing units. While these methods can acquire spatial information to some extent, they are essentially still discrete sampling. To improve spatial resolution, it is usually necessary to increase the number of measuring points or reduce the spacing between them, which directly leads to increased probe size, increased manufacturing complexity, difficulties in arranging internal channels, and enhanced disturbance to the original flow field.

[0004] For microchannels, narrow gaps, and regions with high local gradients, the larger the probe size, the more significant the interference to the measured object. Therefore, probe miniaturization is an important development direction in these situations. At the same time, after probe miniaturization, the number of measurement units that can be arranged inside is significantly limited. If the traditional multi-point fixed layout is still used, problems such as insufficient number of measurement points, incomplete spatial coverage, and difficulty in reconstructing continuous distribution will easily occur.

[0005] In sensing technology, while traditional electrical sensors are widely used, they have certain limitations in high-temperature and strong electromagnetic environments. For example, piezoresistive, resistive, and other electrical signal output methods are easily affected by temperature drift, electromagnetic interference, and lead arrangement conditions, and their long-term stability in high-temperature environments is limited. In contrast, fiber optic sensing technology has advantages such as high-temperature resistance, resistance to electromagnetic interference, suitability for long-distance transmission, and ease of miniaturization and integration. Among them, sapphire fiber optic sensing structures based on the Fabry-Perot interferometry principle are particularly suitable for measuring minute displacement, pressure, or strain signals in complex high-temperature environments.

[0006] However, existing fiber optic FP sensing technologies are mostly based on single-point measurements, i.e., high-precision detection at a fixed location. While single-point measurement structures offer high stability and sensitivity, they still suffer from limited measurement range when dealing with objects exhibiting distinct spatial distribution characteristics. If multiple fiber optic sensor heads are deployed simultaneously, the problems of structural complexity, increased probe size, and spatial arrangement difficulties associated with multi-point fixed measurements become apparent again.

[0007] Therefore, achieving "continuous spatial distribution measurement with fewer sensing channels" in small-scale probes is a key direction for the development of this type of technology. This application proposes a rotating scanning dual-channel sapphire fiber optic FP miniature sensing probe based on the aforementioned technological background. Summary of the Invention

[0008] The purpose of this application is to solve the technical problems existing in the prior art and to provide a sapphire fiber optic FP dual-sensor micro probe and measurement method based on rotation scanning. By introducing a dual-channel structure that combines a reference measurement channel and a rotation scanning measurement channel, continuous spatial measurement can be achieved at an extremely small probe scale.

[0009] To solve the technical problem, the technical solution of this application is: a sapphire fiber optic FP dual-sensor micro probe based on rotation scanning, including an integrally formed spherical probe and a connecting rod, the bottom of which is fastened to a micro transmission component; The spherical probe is provided with a top strip strain membrane at the top, and the spherical probe below the top strip strain membrane has a top strain membrane cavity. The top strain membrane cavity is provided with a top optical sensor, and the bottom of the top optical sensor is connected to a top-coupled sapphire optical fiber. The spherical probe has a central strip strain membrane arranged circumferentially around the spherical probe. The spherical probe inside the central strip strain membrane has a circumferentially arranged central strip strain membrane cavity. A rotating optical sensor is disposed in the central strip strain membrane cavity, and the tail of the rotating optical sensor is connected to a rotating coupled sapphire optical fiber. The connecting rod has a through hole inside, through which both the top-coupled sapphire fiber and the rotationally coupled sapphire fiber pass. The micro transmission assembly includes a housing, a motor, a cross-type coupling, a ceramic body boss, and a fiber optic data acquisition card. The motor is fixed to the bottom inside the housing. The power output end of the motor is connected to the cross-type coupling, and the other end of the cross-type coupling is connected to the ceramic body boss. The fiber optic data acquisition card is set at the center of the top of the ceramic body boss. The motor is electrically connected to the fiber optic data acquisition card. The top-coupled sapphire fiber and the rotary-coupled sapphire fiber ends are respectively connected to and fixed to the fiber optic data acquisition card; The top optical sensor and the top-coupled sapphire fiber form a reference measurement channel for acquiring reference signals; the rotating optical sensor and the rotating-coupled sapphire fiber form a rotating scanning channel for scanning measurements at different circumferential positions of the central strip-shaped strain film.

[0010] Preferably, the bottom of the connecting rod is provided with an arc-shaped opening, and the micro transmission assembly also includes an external ceramic sleeve. The ceramic body boss is fitted into the inner ring of the bottom of the external ceramic sleeve, the top of the external ceramic sleeve protrudes out of the outer shell, and the top of the external ceramic sleeve passes through the arc-shaped opening and is fixed in the through hole. Preferably, the connecting rod has two arc-shaped openings at its bottom center, and the top of the outer ceramic sleeve has two arc-shaped connectors, which are respectively inserted into the two arc-shaped openings.

[0011] Preferably, the bottom edge of the connecting rod is provided with a connecting annular protrusion, and the top edge of the outer casing is provided with an annular groove, the annular protrusion and the annular groove engaging with each other.

[0012] Preferably, the diameter of the spherical probe is 2.5~3.5mm, and the equivalent outer diameter of the rotating optical sensor is... equivalent inner diameter Equivalent body length Equivalent overhang length equivalent quality Equivalent material elastic modulus .

[0013] Preferably, the motor is an adaptive variable step size resampling motor.

[0014] Preferably, the rotary-coupled sapphire optical fiber includes an integrally formed arc segment and a straight segment, with the front end of the arc segment connected to a rotary optical sensor and the rear end of the straight segment connected to an optical fiber data acquisition card.

[0015] Preferably, the rotating optical sensor is supported by an upper and lower double support structure, a coaxial sleeve limiting structure, or a short cantilever plus radial limiting structure.

[0016] A preferred measurement method based on a sapphire fiber optic dual-sensor microprobe using rotational scanning includes the following steps: Step 1: Install the sapphire fiber FP dual-sensor micro probe based on rotational scanning into the flow field to be measured; Step 2: The motor drives the rotating optical sensor to scan and measure at different circumferential positions of the central strip strain membrane. At the same time, the top optical sensor and the rotating optical sensor transmit the collected data to the fiber optic data acquisition card to form a voltage signal. Step 3: Voltage signal synchronization; The motor feeds back the pulse-coded signal of its rotor position to the fiber optic data acquisition card in real time, which serves as the spatial positioning and timestamp alignment reference for the interference data; Step 4: Reconstruct the interference spectrum from the synchronized voltage signal, extract the FP cavity length, and calculate the cavity length change. The original cavity length change was obtained by demodulating the rotating scanning channel. The change in raw cavity length demodulated from the reference measurement channel ; Step 5: Use dual-channel dynamic spatiotemporal differential compensation to compensate for nonlinear errors; utilize the original cavity length variation demodulated from the rotating scanning channel. The change in raw cavity length demodulated from the reference measurement channel The actual flow field deformation displacement after removing common-mode errors was calculated. ; Step 6: Calculate the actual flow field deformation displacement. The physical quantities are converted, and then the spatial distribution is reconstructed to obtain the pressure data of the flow field to be measured.

[0017] Preferably, the actual flow field deformation displacement The calculation formula is: ; In the formula: As temperature The variable structural coupling transfer coefficient.

[0018] Compared with the prior art, the advantages of this application are: (1) This application proposes a sapphire fiber FP dual-sensor micro probe based on rotation scanning. The probe transforms the traditional "multi-point spatial measurement" into a "reference measurement + single-point rotation scanning measurement" measurement method by setting a reference measurement channel and a rotation scanning measurement channel. While ensuring the miniaturization of the probe (the diameter of the spherical probe at the front end is about 3mm) and high temperature adaptability, it realizes continuous spatial distribution measurement of the measured area. (2) The top optical sensor and the top coupled sapphire fiber constitute a reference measurement channel for acquiring reference signals. The rotating optical sensor and the rotating coupled sapphire fiber constitute a rotating scanning channel for scanning measurements at different circumferential positions of the central strip strain film. The reference measurement channel and the rotating scanning channel do not interfere with each other, thus improving measurement stability. (3) The rotating optical sensor of this application adopts limited angle reciprocating scanning or step scanning to avoid long-term unbounded torsion of the rotating coupled sapphire fiber. Furthermore, the rotating optical sensor reduces the error caused by long-term drooping through lightweight and dual support structure. (4) This application breaks with the conventional order of calculating physical quantities first and then performing back-end filtering, and adjusts the processing logic to: "phase pulse hardware-level synchronization". "Level-difference operation of cavity length" "Final physical quantity conversion and spatial reconstruction" benefited from the structure of the bottom motor directly driving the optical fiber and the optical fiber directly driving the optical sensor. At the physical level, all independent transmission shafts and gears were eliminated. This structure, combined with hardware-level phase synchronization, made the angle output by the bottom motor equivalent to the deflection angle of the rotating optical sensor without delay or deviation. This completely eliminated the "mechanical backlash" introduced by the tiny processing gaps, so that the reconstructed continuous spatial distribution field had no trailing or distortion under high-frequency scanning. (5) The diameter of the spherical probe of this application is 2.5~3.5mm. The probe size is small and has little interference to the flow field. Furthermore, it utilizes the FP principle of sapphire fiber and has advantages such as high temperature resistance and electromagnetic interference resistance. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the sapphire fiber optic dual-sensor micro probe based on rotational scanning in this application. Figure 2 For this application Figure 1 AA section view; Figure 3 This is a schematic diagram showing the disassembled sapphire fiber optic dual-sensor micro probe based on rotational scanning according to this application. Figure 4 This is a comparison chart showing the verification and effect of the adaptive variable step size sampling mechanism of this application; Figure 5 This is a diagram showing the effect of dynamic differential compensation at the bottom cavity length level of this application on cleaning common-mode interference.

[0020] Explanation of reference numerals in the attached figures: 1. Spherical probe; 2. Connecting rod; 3. Miniature transmission assembly; 1-1. Top strip strain membrane; 1-2. Top strain membrane cavity; 1-3. Top optical sensor; 1-4. Middle strip strain membrane; 1-5. Middle strip strain membrane cavity; 1-6. Rotating optical sensor; 1-7. Top-coupled sapphire fiber; 1-8. Rotationally coupled sapphire fiber. 2-1. Through hole; 2-2. Arc-shaped opening; 2-3. Annular protrusion; 3-1. Outer casing; 3-2. Motor; 3-3. Cross-type coupling; 3-4. Ceramic body boss; 3-5. Fiber optic data acquisition card; 3-6. External ceramic sleeve. Detailed Implementation

[0021] The present application is described in detail below with reference to the accompanying drawings and specific embodiments, but the present application is not limited to these embodiments. The present application covers any alternatives, modifications, equivalent methods, and solutions made within the spirit and scope of the present application. To provide the public with a thorough understanding of the present application, specific details are described in detail in the following embodiments, but those skilled in the art will fully understand the present application even without these detailed descriptions.

[0022] This application introduces the concept of scanning measurement, transforming the spatial measurement that originally relied on multiple fixed measurement points to be completed simultaneously into a single measurement point scanning point by point at different spatial locations over time, and then spatially reconstructing the sampling results; this approach can improve spatial resolution and information acquisition capabilities without significantly increasing the probe size.

[0023] like Figures 1-3 As shown, this application discloses a sapphire fiber optic FP dual-sensor micro probe based on rotation scanning, including an integrally formed spherical probe 1 and a connecting rod 2, the bottom of the connecting rod 2 being fastened to a micro transmission component 3; The spherical probe 1 is provided with a top strip strain membrane 1-1 at the top, and the spherical probe 1 below the top strip strain membrane 1-1 is provided with a top strain membrane cavity 1-2. The top strain membrane cavity 1-2 is provided with a top optical sensor 1-3, and the bottom of the top optical sensor 1-3 is connected to a top-coupled sapphire optical fiber 1-7. The spherical probe 1 has a central strip strain membrane 1-4 arranged circumferentially around the center of the spherical probe 1. The spherical probe 1 inside the central strip strain membrane 1-4 has a circumferentially arranged central strip strain membrane cavity 1-5. The rotating optical sensor 1-6 is disposed in the central strip strain membrane cavity 1-5. The tail of the rotating optical sensor 1-6 is connected to a rotating coupled sapphire optical fiber 1-8. The connecting rod 2 has a through hole 2-1 inside, through which the top-coupled sapphire fiber 1-7 and the rotationally coupled sapphire fiber 1-8 both pass. The micro transmission assembly 3 includes a housing 3-1, a motor 3-2, a cross-type coupling 3-3, a ceramic body boss 3-4, and a fiber optic data acquisition card 3-5. The motor 3-2 is fixed to the bottom inside the housing 3-1. The power output end of the motor 3-2 is connected to the cross-type coupling 3-3, and the other end of the cross-type coupling 3-3 is connected to the ceramic body boss 3-4. The fiber optic data acquisition card 3-5 is set at the top center of the ceramic body boss 3-4. The motor 3-2 is electrically connected to the fiber optic data acquisition card 3-5. The ends of the top-coupled sapphire fiber 1-7 and the rotary-coupled sapphire fiber 1-8 are respectively connected to and fixed to the fiber optic data acquisition card 3-5; The top optical sensor 1-3 and the top coupled sapphire fiber 1-7 form a reference measurement channel for acquiring reference signals; the rotating optical sensor 1-6 and the rotating coupled sapphire fiber 1-8 form a rotating scanning channel for scanning measurements at different circumferential positions of the central strip strain membrane 1-4.

[0024] Preferably, the bottom of the connecting rod 2 is provided with an arc-shaped opening 2-2, and the micro transmission component 3 also includes an external ceramic sleeve 3-6. The ceramic body boss 3-4 is fitted into the inner ring of the bottom of the external ceramic sleeve 3-6, the top of the external ceramic sleeve 3-6 protrudes through the outer shell 3-1, and the top of the external ceramic sleeve 3-6 passes through the arc-shaped opening 2-2 and is fixed in the through hole 2-1. Preferably, the bottom center of the connecting rod 2 is provided with two arc-shaped openings 2-2, and the top of the outer ceramic sleeve 3-6 is provided with two arc-shaped connectors, which are respectively inserted into the two arc-shaped openings 2-2.

[0025] Preferably, the bottom edge of the connecting rod 2 is provided with a connecting annular protrusion 2-3, and the top edge of the outer shell 3-1 is provided with an annular groove, the annular protrusion 2-3 and the annular groove engaging with each other.

[0026] Preferably, the diameter of the spherical probe 1 is 2.5~3.5mm, and the equivalent outer diameter of the rotating optical sensors 1-6 is... equivalent inner diameter Equivalent body length Equivalent overhang length equivalent quality Equivalent material elastic modulus .

[0027] Preferably, the motor 3-2 is an adaptive variable step size resampling motor.

[0028] Preferably, the rotary-coupled sapphire optical fiber 1-8 includes an integrally formed arc segment and a straight segment. The front end of the arc segment is connected to the rotary optical sensor 1-6, and the rear end of the straight segment is connected to the optical fiber data acquisition card 3-4.

[0029] Preferably, the rotating optical sensors 1-6 are supported by an upper and lower double support structure, a coaxial sleeve limiting structure, or a short cantilever plus radial limiting structure.

[0030] A preferred measurement method based on a sapphire fiber optic dual-sensor microprobe using rotational scanning includes the following steps: Step 1: Install the sapphire fiber FP dual-sensor micro probe based on rotational scanning into the flow field to be measured; Step 2: Motor 3-2 drives the rotating optical sensor 1-6 to scan and measure at different circumferential positions of the central strip strain membrane 1-4. At the same time, the top optical sensor 1-3 and the rotating optical sensor 1-6 transmit the collected data to the fiber optic data acquisition card 3-5 to form a voltage signal. Step 3: Voltage signal synchronization; Motor 3-2 feeds back the pulse-coded signal of its rotor position to the fiber optic data acquisition card 3-5 in real time, which serves as the spatial positioning and timestamp alignment reference for the interference data; Step 4: Reconstruct the interference spectrum from the synchronized voltage signal, extract the FP cavity length, and calculate the cavity length change. The original cavity length change was obtained by demodulating the rotating scanning channel. The change in raw cavity length demodulated from the reference measurement channel ; Step 5: Use dual-channel dynamic spatiotemporal differential compensation to compensate for nonlinear errors; utilize the original cavity length variation demodulated from the rotating scanning channel. The change in raw cavity length demodulated from the reference measurement channel The actual flow field deformation displacement after removing common-mode errors was calculated. ; Step 6: Calculate the actual flow field deformation displacement. The physical quantities are converted, and then the spatial distribution is reconstructed to obtain the pressure data of the flow field to be measured.

[0031] Preferably, the actual flow field deformation displacement The calculation formula is: ; In the formula: As temperature The variable structural coupling transfer coefficient.

[0032] Example 1 The miniature probe of this application has an overall axisymmetric structure, with a spherical probe at the front end having a diameter of 3 mm and a corresponding radius of 1.5 mm. This size, while ensuring structural strength, can significantly reduce the blocking effect on the flow field and reduce the influence of the probe itself on the original field distribution.

[0033] The top strip strain membrane 1-1 is disposed in the top region of the spherical probe 1, and a top strain membrane cavity 1-2 is formed below it. The top optical sensor 1-3 is installed in the top strain membrane cavity 1-2. During operation, it only rotates and its unit position remains unchanged. This channel is mainly used to provide a reference measurement signal for the reference position so as to perform system calibration and differential compensation.

[0034] The central strip strain membrane 1-4 is disposed on the outer periphery of the middle region of the spherical probe 1, and a central strip strain membrane cavity 1-5 is formed inside it. The rotating optical sensor 1-6 is disposed in the central strip strain membrane cavity 1-5, and performs point-by-point scanning measurement at different circumferential positions of the central strip strain membrane 1-4 through rotational movement.

[0035] The top optical sensor 1-3 and the top coupled sapphire fiber 1-7 form a reference measurement channel for acquiring reference signals; the rotating optical sensor 1-6 and the rotating coupled sapphire fiber 1-8 form a rotating scanning channel for scanning measurements at different circumferential positions of the central strain membrane 1-4.

[0036] With the above structure, this application does not use multiple independent fixed measuring points, but adopts a dual-channel structure of "one reference measuring point + one rotating scanning measuring point", which achieves continuous spatial distribution measurement while maintaining a compact structure.

[0037] This application constructs an optomechanical co-driven direct-drive and synchronous acquisition system, whose data flow and physical transmission process are as follows: Physical transmission flow: The system power source is a micro transmission component set at the bottom of the spherical probe. The micro transmission component outputs rotational torque to the bottom end of the rotary coupled sapphire fiber 1-8. The rotary coupled sapphire fiber 1-8 serves as both an optical signal transmission waveguide and a rigid mechanical transmission medium. The torque is transmitted upward along the fiber, directly driving the rotary optical sensor 1-6 to achieve reciprocating scanning at a limited angle.

[0038] Data flow: After the top strip strain membrane 1-1 and the middle strip strain membrane 1-4 are subjected to pressure deformation, the inner cavity 1-2 of the top strain membrane and the inner cavity 1-5 of the middle strip strain membrane are deformed. The light beam is reflected by the top and middle strip strain membranes to form FP interference light. After the top optical sensor 1-3 and the rotating optical sensor 1-6 detect the data, it enters the top coupled sapphire fiber (forming the reference measurement channel) and the rotating coupled sapphire fiber (forming the rotating scanning channel) respectively, and is converted into a voltage signal array, and finally input into the fiber optic data acquisition card 3-5.

[0039] Example 2 To further improve the stability and transmission accuracy of the micro probe in high-temperature and complex flow fields, this application designs a special heat-resistant and high-precision micro transmission assembly at the power input end at the bottom of the probe. The micro transmission assembly includes, from bottom to top: a motor 3-2, a cross-type coupling 3-3, a ceramic body boss 3-4, and an outer ceramic sleeve 3-6 that surrounds the periphery. A fiber optic data acquisition card 3-5 is installed at the center of the top of the ceramic body boss 3-4.

[0040] Motor: As the drive source, it is located at the farthest end of the probe (relatively low temperature zone). The motor outputs a precisely controlled finite-angle reciprocating scanning torque according to the system's adaptive variable step size resampling logic.

[0041] Cross-type coupling: connects the motor output shaft to the ceramic boss at the front end. Due to the extremely small overall space of the probe (the front diameter is only 3mm), microscopic coaxiality deviations are easily generated during assembly. The introduction of the cross-type coupling effectively absorbs these tiny radial and angular errors; more importantly, it plays a crucial mechanical filtering role, isolating the high-frequency mechanical vibrations generated during motor operation and preventing them from being transmitted upwards to the sensitive optical interference cavity, thereby purifying the background noise of the underlying optical signal.

[0042] Ceramic boss: It bears the torque of the cross coupling and is rigidly connected to the bottom end of the upper rotary coupling sapphire optical fiber 1-8. The use of special ceramic material here has dual technical benefits: On the one hand, ceramic has extremely high mechanical rigidity, ensuring that the torque output by the motor is transmitted to the rotary optical sensor 1-6 without hysteresis and with zero backlash, meeting the requirements for accurate reconstruction of spatial distribution; on the other hand, by utilizing the excellent thermal insulation properties of ceramic, the ceramic boss forms an effective "thermal break" between the high-temperature hot end (probe head) and the room-temperature cold end (bottom motor), preventing high-temperature heat flow from being conducted downward through the transmission main shaft and thus damaging the drive motor.

[0043] External ceramic sleeve: It has a cylindrical structure and is fitted around the outer periphery of the internal ceramic body boss, with its upper end abutting the bottom of the connecting rod. The external ceramic sleeve not only provides radial centering support with high coaxiality for the internal rotating parts and plays a guiding role, but also acts as an external heat insulation barrier at the bottom of the system, further preventing the high-temperature environment of the complex flow field from intruding into the internal precision electromechanical components.

[0044] The beneficial effects of this structural design are: This composite physical architecture of "motor direct drive + coupling flexible vibration reduction + ceramic rigid transmission and heat insulation" perfectly matches the high-precision measurement requirements of the sapphire fiber optic FP sensing system. It not only ensures high synchronization transmission in a confined space (eliminating mechanical hysteresis), but also achieves excellent "thermal-mechanical" physical isolation, solving the industry pain point of microelectromechanical systems being prone to failure in high-temperature flow fields from the hardware level.

[0045] Example 3 This application discloses a measurement method for a sapphire fiber optic dual-sensor micro probe based on rotational scanning, comprising the following steps: Step 1: Install the sapphire fiber FP dual-sensor micro probe based on rotational scanning into the flow field to be measured; Step 2: The top optical sensor 1-3 and the rotating optical sensor 1-6 transmit the collected data to the fiber optic data acquisition card 3-5 respectively, forming a voltage signal; Step 3: Voltage signal synchronization; The motor 3-2 feeds back the pulse-coded signal of its rotor position to the fiber optic data acquisition card 3-5 in real time, which serves as the spatial positioning and timestamp alignment reference for the interference data; The bottom motor 3-2 feeds back its rotor position pulse-coded signal to the fiber optic data acquisition card 3-5 in real time, serving as a spatial positioning and timestamp alignment reference for the interferometric data. This achieves hardware-level "zero-delay" synchronous binding of physical spatial coordinates and optical interferometric data. This bottom-up direct-drive transmission path keeps the heat source and vibration source away from the temperature-sensitive FP interferometer cavity, significantly improving the stability of hot-end measurements.

[0046] Step 4: Reconstruct the interference spectrum from the synchronized voltage signal, extract the FP cavity length, and calculate the cavity length change. The original cavity length change was obtained by demodulating the rotating scanning channel. The change in raw cavity length demodulated from the reference measurement channel ; After acquiring the voltage signal array, the fiber optic data acquisition card 3-5 performs the following demodulation and calculation steps: Interference spectrum demodulation: The voltage signal is restored to an interference spectrum, and the FP cavity length is extracted. The demodulation is based on the interference spectrum formula: In the formula, The intensity of the reflected interference light received by the optical sensor; The wavelength of the incident light; and These are the reflected light intensities from the end face of the sapphire fiber and the inner surface of the strain film, respectively. The real-time FP cavity length (i.e., the diaphragm deformation displacement caused by the measured physical quantity). is the initial phase constant.

[0047] Dynamic scanning position calculation: The real-time spatial position of the probe is calculated synchronously based on the pulse code signal. The calculation model is as follows: In the formula, For rotating optical sensors in The angular position at any given moment; The maximum scanning angle amplitude (preferred in this embodiment) ); The reciprocating scanning angular frequency; This serves as the initial installation reference angle; This represents the actual scanning arc length trajectory on the central strip-shaped strain membrane; The center scan radius (preferably) is the center scan radius. ).

[0048] Step 5: Use dual-channel dynamic spatiotemporal differential compensation to compensate for nonlinear errors; utilize the original cavity length variation demodulated from the rotating scanning channel. The change in raw cavity length demodulated from the reference measurement channel The actual flow field deformation displacement after removing common-mode errors was calculated. ; To eliminate common-mode interference from probe thermal expansion, structural sagging, and motor vibration in high-temperature complex flow fields, this application employs dual-channel dynamic spatiotemporal differential compensation. The core of this approach lies in placing the differential step at the bottom cavity length scale. The compensation formula is as follows: In the formula, As temperature The varying structural coupling transmission coefficient. By differentially truncating the length of the bottom interferometric cavity, the top-coupled sapphire fiber serves as a mirror reference source for the mechanical vibration and sag of the scanning fiber, directly cutting off the nonlinear error transmission from the optical root.

[0049] Step 6: Calculate the actual flow field deformation displacement. Physical quantity conversion and spatial distribution reconstruction are performed to obtain the detected pressure data.

[0050] This application breaks with the conventional order of calculating physical quantities first and then performing back-end filtering, adjusting the processing logic to: "phase pulse hardware-level synchronization". "Level-difference operation of cavity length" "Final physical quantity conversion and spatial reconstruction" benefited from the structure of the bottom motor directly driving the optical fiber and the optical fiber directly driving the optical sensor. At the physical level, all independent transmission shafts and gears were eliminated. This structure, together with hardware-level phase synchronization, made the angle output by the bottom motor equivalent to the deflection angle of the rotating optical sensor 1-6 without delay or deviation. This completely eliminated the "mechanical backlash" introduced by the tiny processing gap, so that the reconstructed continuous spatial distribution field had no trailing and no distortion under high-frequency scanning.

[0051] Example 4 In this application, the rotating optical sensor 1-6 is connected to the fiber optic data acquisition card 3-5 through a rotating coupled sapphire optical fiber 1-8. The rotating coupled sapphire optical fiber 1-8 plays the role of data transmission and also drives the rotating optical sensor 1-6 to rotate. Its movement mode can adopt step-type circumferential scanning or limited angle reciprocating scanning.

[0052] In a preferred embodiment, instead of unrestricted continuous rotation, the oscillation is limited to a preset angle range to reduce the cumulative torsional stress of the rotationally coupled sapphire fiber and improve long-term stability.

[0053] In a finite-angle reciprocating scanning mode, the angular position of the rotating optical sensor can be expressed as: Where θ(t) is the angular position at time t, θm is the maximum scanning angular amplitude, ω is the scanning angular frequency, and θ0 is the initial installation angular position.

[0054] In a preferred embodiment of this application, the maximum scanning angle amplitude is: That is, the rotating optical sensor performs reciprocating scanning within a range of ±15°. If the central scanning radius is rm = 1.2mm, then the corresponding scanning arc length is: Therefore, the maximum single-sided scanning arc length is approximately 0.314 mm, and the total arc length covered by the reciprocating scan is approximately 0.628 mm. This scanning range is sufficient to meet the requirements for point-by-point sampling of local circumferential areas within a small-scale probe.

[0055] The top-coupled sapphire fiber and the top optical sensor form a reference measurement channel, arranged along the probe axis and isolated from the motion area of ​​the rotating optical sensor by an independent channel. Therefore, during scanning, the rotating optical sensor does not directly drive the top-coupled sapphire fiber to rotate, nor does it transmit torque to the top-coupled sapphire fiber, thus ensuring the stability of the output of the reference measurement channel.

[0056] A rotary-coupled sapphire fiber is connected to a rotating optical sensor for transmitting scanning measurement signals. To prevent the entire sapphire fiber from continuously twisting with the scanning unit, this application only allows the rotary-coupled sapphire fiber to bear limited angular displacement in a short local segment near the rotating optical sensor, while the remaining portion achieves stress relief through a fixed channel, a flexible compensation section, or a coaxial coupling section.

[0057] For this short segment of local compensation, estimation can be performed using a circular cross-section torsion model. If the outer diameter of the rotationally coupled sapphire fiber is taken as... ,radius If the length of the locally compensated segment is Lc = 1.0 mm, then its polar moment of inertia is: If the shear modulus of sapphire is taken as G = 145 GPa, then the equivalent torsional stiffness of this locally compensated section is: When the maximum scan angle amplitude is 15°, that is When the torque is 0.2618 rad, the equivalent torque borne by the locally compensated short segment is approximately: Therefore, it can be seen that under the limited angle reciprocating scanning mode, the torsional load borne by the local short segment at the near end of the rotationally coupled sapphire fiber is within a controllable range and will not produce unbounded cumulative torsion as in continuous rotation.

[0058] Furthermore, the maximum shear strain on the locally compensated short-segment outer surface can be expressed as: Substitution , , We can obtain: Right now: If the maximum scanning angle amplitude is 10°, the corresponding maximum shear strain is approximately 1.09%; if the maximum scanning angle amplitude is 5°, the corresponding maximum shear strain is approximately 0.55%. This indicates that when the scanning angle amplitude is controlled within a small angle range, the torsional deformation experienced by the near-end compensation section of the rotationally coupled sapphire fiber is limited and designable.

[0059] Therefore, this application clarifies the specific motion mode of the rotating optical sensor and its influence on the two sapphire fiber channels by using a method of "limited-angle reciprocating scanning of the rotating optical sensor + limited torsion compensation of a local short segment of the rotating coupled sapphire fiber". This design ensures the scanning measurement function while avoiding the problems of interference with the reference measurement channel and continuous torsion of the long segment of the rotating coupled sapphire fiber.

[0060] Example 5 If the rotating optical sensor 1-6 uses a large-mass integral optical component, it is prone to sagging due to its own weight after long-term operation, causing changes in the gap between it and the central strip-shaped strain membrane 1-4, which in turn leads to measurement errors and reduced repeatability. To solve this problem, this application has specifically optimized the rotating optical sensor 1-6.

[0061] First, the rotating optical sensors 1-6 adopt a lightweight design, preferably a short, hollow rotating scanning structure, and can specifically adopt at least one of the following structural forms: 1. Hollow structure; 2. Partially hollowed-out structure; 3. Short probe structure; 4. Lightweight high-temperature resistant ceramic or lightweight composite material encapsulation structure.

[0062] In the preferred embodiment of the application, the design parameters of the rotating optical sensors 1-6 are as follows: equivalent outer diameter ; equivalent inner diameter ; Equivalent Body Length ; Equivalent overhang length ; equivalent quality ; Equivalent material elastic modulus ; Secondly, the rotating optical sensors 1-6 do not adopt a long cantilever free-end form, but are instead supported by a dual support of a micro-rotation support and a drive mechanism, or by a short cantilever support. Preferably, the support method is as follows: 1. Double support structure (top and bottom); 2. Coaxial sleeve limiting structure; 3. Short cantilever with radial limiting structure.

[0063] The above-mentioned support method can significantly reduce the free overhang length of the rotating optical sensors 1-6 and suppress bending and sagging caused by their own weight.

[0064] Furthermore, the center of gravity of the rotating optical sensors 1-6 is positioned as close as possible to the support location to reduce eccentric loads and long-term sway. Approximating it as a cantilever structure with a circular cross-section, its moment of inertia is: Substitution We can obtain: The equivalent gravitational load of the rotating optical sensors 1-6 is: The maximum deflection caused by its own weight can be expressed as: Substituting L=0.80mm, E=300GPa and the above parameters, we get: Right now: Therefore, it can be seen that after adopting a lightweight, short cantilever and high rigidity design, the static sag of the rotating optical sensors 1-6 due to weight is much smaller than the effective micron-level measurement displacement of the strain membrane, and will not have a significant impact on the scanning measurement gap.

[0065] Furthermore, based on the first-order natural frequency model of the cantilever beam, the first-order natural frequency of the rotating optical sensors 1-6 is estimated to be approximately: Right now: Meanwhile, the moment of inertia of the rotating optical sensors 1-6 is approximately: The above values ​​show that the rotating optical sensor 1-6 not only has extremely small self-weight deflection, but also good structural dynamic stability and low driving inertia, making it suitable for achieving limited-angle reciprocating scanning control using a micro-rotating support and drive mechanism.

[0066] The scanning radius of the rotating optical sensors 1-6 on the central strip-shaped strain film is: The perimeter of the scan trajectory in one week is: During the scanning process, the circumferential position satisfies: When the angle step size is When the circumferential spatial resolution is: in Use radians.

[0067] When the angle step length is taken When, the corresponding radian is approximately ,but: When the angle step length is taken Then: Therefore, it can be seen that this application can directly improve spatial resolution by increasing angular resolution.

[0068] Because the banded strain membrane is relatively narrow, its local stress can be approximated as a small beam structure fixed at both ends. Under external pressure, its local displacement satisfies: in: Angular position Local displacement of the strain membrane; The corresponding external pressure or equivalent load at the location; l is the local effective length; h is the film thickness; E is the Young's modulus of the material; This is the structural correction factor.

[0069] In the preferred embodiment of this application, the following is taken: ; ; ; ; When the external pressures are 0.1 MPa, 0.5 MPa, 1.0 MPa, and 1.5 MPa, the local displacements of the strain membrane are approximately: ; ; ; ; This shows that, within the design pressure range, the strain membrane displacement is on the order of micrometers, making it suitable for high-precision demodulation of fiber optic FP interferometric signals.

[0070] This application employs a sapphire fiber FP cavity structure for measurement. When the strain membrane undergoes a minute displacement, it will cause a corresponding change in the FP cavity length: in, is the displacement transfer coefficient.

[0071] Furthermore, changes in cavity length will cause a shift in the interference spectrum: in: This is the wavelength shift. This is the initial operating wavelength; This is the initial cavity length.

[0072] By combining the strain film displacement model and the optical demodulation relationship, a direct relationship between pressure and wavelength drift can be obtained: The above formulas are all calculation relationships based on existing models, used to convert scanning measurement signals into corresponding physical quantities.

[0073] To ensure the dynamic performance of the rotating scanning measurement, the natural frequency of the strain membrane was designed: in: It is the first-order natural frequency; 1 represents the modal coefficient; l is the characteristic length; E is the Young's modulus of the material; h is the film thickness; This represents the material density.

[0074] In the preferred embodiment of this application, the following is taken: =4.73; l=0.8mm; h=30 ; E=410GPa; ; Substituting the values, we can obtain the first natural frequency of the strained membrane as approximately: Right now: This result demonstrates that the strained membrane body possesses high dynamic response potential, providing a structural basis for high-frequency dynamic measurements.

[0075] Example 6 This application provides a sapphire fiber optic FP dual-sensor micro probe based on rotational scanning. Combined with specific miniaturized application scenarios (such as flow field measurement with a front-end spherical probe diameter of approximately 3mm), this probe utilizes an optomechanical collaborative direct-drive architecture and has undergone deep optimization of the underlying data flow and processing mechanisms. The specific implementation method and operation control steps are as follows: 1. An optomechanical integrated transmission and data synchronization mechanism with finite angle constraints; To achieve extreme miniaturization of the probe, this embodiment abandons traditional independent mechanical transmission components and directly uses a waveguide with high Young's modulus (i.e., a rotationally coupled sapphire fiber) as a rigid mechanical transmission medium. A micromotor at the bottom of the probe outputs rotational torque, which directly drives the rotating optical sensor through this fiber.

[0076] Considering that single-crystal sapphire is a brittle material, this system sets strict rigid constraints in its motion control logic: the scanning parameters are forcibly limited to a restricted finite angle (e.g., The optical fiber undergoes a reciprocating scanning motion (within the optical fiber). This mechanism satisfies the scanning requirements for high spatial resolution while fundamentally preventing fiber breakage due to excessive twisting. Simultaneously, the bottom micro-motor feeds back the pulse-coded signal of its rotor position to the optical fiber data acquisition card in real time, serving as a spatial positioning and timestamp alignment reference for subsequent interference data, thus achieving hardware-level synchronization between physical space and optical signals.

[0077] 2. Variable step size resampling operation control based on adaptive angular velocity; Because the probe is limited to a finite angular reciprocating motion, its angular velocity exhibits a nonlinear characteristic of being fast in the middle and slow at both ends. If the constant frequency isochronous sampling of a conventional white light interferometric FP demodulator is used, the sampling points will be sparse when the probe is in the middle position, while the data will be severely piled up and overlapped at the extreme positions on both sides.

[0078] To address this, the system innovatively introduces an adaptive variable step size resampling control strategy: the real-time angular velocity signal of the micro motor is directly connected to the external trigger loop of the spectral acquisition module, and the sampling frequency parameters of the demodulator are dynamically adjusted so that they are directly proportional to the absolute value of the real-time angular velocity of the motor.

[0079] like Figure 4 The figure shows the verification and effect comparison of the adaptive variable step size sampling mechanism. This mechanism changes the system driving source from "clock driving" to "spatial displacement driving", which effectively avoids the computational overload caused by data redundancy during edge scanning of the lower computer and ensures the absolute uniformity of the effective spatial resolution of the flow field cross section.

[0080] 3. Dual-channel bottom-level cavity long-stage dynamic spatiotemporal differential processing flow; In high-temperature, harsh flow fields, the probe is subject to common-mode interference such as thermal expansion and motor vibration. Existing systems typically calculate the final pressure / strain values ​​first and then perform software subtraction, at which point the error is amplified by the nonlinear response of the sensitive diaphragm and phase distortion occurs. This application breaks with the conventional approach and constructs a "pulse hardware-level binding" system. Low-level cavity length differential A brand-new processing flow for "physical quantity conversion": Extraction of the original interferometric cavity length: Using a demodulation algorithm, the original interferometric cavity length affected by interference is extracted from the spectral signals of the reference measurement channel and the rotating scanning channel, respectively. and Low-level interferometric pre-differentiation: Performing differential operations directly at the nanometer-scale interferometric cavity length without any physical quantity conversion. (in (This refers to the temperature coupling transfer coefficient).

[0081] Converting to real physical quantities: Finally, the change in length of the cleaned cavity. Substitute the parameters into the mechanistic model and convert them into actual flow field physical parameters.

[0082] like Figure 5The image shows the effect of dynamic differential compensation at the bottom cavity length level on common-mode interference removal. By placing the differential action at the lowest optical level, the top-fixed sapphire fiber perfectly serves as a real-time mirror reference source for the "baseline thermal drift and mechanical vibration" of the scanning channel. This completely eliminates the error from its optical origin before it is amplified by the nonlinear model, resulting in a reconstructed continuous spatial distribution curve of the flow field with excellent performance, including no trailing and high overlap between forward and reverse trajectories.

[0083] This application improves the stability of the technical solution through the following measures: 1. It is clear that the rotating optical sensor uses limited-angle reciprocating scanning or step scanning, rather than unlimited continuous rotation; 2. Clarify the relationship between the rotating optical sensor and the top-coupled sapphire fiber and the rotationally coupled sapphire fiber. The top-coupled sapphire fiber rotates along the central axis but remains stationary, while the rotationally coupled sapphire fiber only couples with the rotating optical sensor at a limited angular displacement in the near end. 3. By using a lightweight rotating optical sensor, a dual-support structure, and a short cantilever arrangement, the long-term sag and deflection changes of the rotating optical sensor caused by its own weight are reduced. 4. Converge the overall technical solution towards the direction of "fiber optic sensor / miniature sensing probe" to improve its compatibility with the rapid pre-screening and classification direction.

[0084] 5. Dual-channel optomechanical decoupling and underlying dynamic differential mechanism (signal and transmission level) In a high-temperature, high-frequency vibrating flow field, the signal of a traditional single-channel fiber optic probe is superimposed with thermal expansion and mechanical vibration, making it extremely difficult to peel off. Furthermore, as a brittle and hard material, sapphire fiber is prone to breakage due to the accumulation of torsional stress if conventional continuous rotation scanning is used.

[0085] This solution innovatively constructs a collaborative mechanism of "dual-channel asymmetric arrangement" and "limited-angle local decoupling".

[0086] At the mechanical transmission level: through the decoupling mechanism and control logic, the upward rotational driving force at the bottom only produces a localized, limited angular displacement (reciprocating scan) within the allowable range of material elasticity in the "rotationally coupled sapphire fiber," without interfering with the "top-fixed sapphire fiber." This cleverly resolves the physical contradiction between the "brittle fiber material" and the "dynamic scanning requirements," fundamentally avoiding fiber breakage failure.

[0087] At the signal processing level: the top fixed channel serves as the in-situ real-time environmental reference. Since the two channels are in a very small space and experience the same heat flow environment, the system can use the data from the fixed channel in real time at the low-level data level of optical demodulation to subtract and eliminate common-mode noise (thermal drift and overall jitter) in the rotating channel.

[0088] This "hardware-level optomechanical decoupling + algorithm-level low-level differential" design gives the probe an extremely long mechanical life and completely breaks the limitation of traditional single-point measurement relying on post-process software filtering, achieving high-fidelity extraction of real minute parameters of the flow field under harsh working conditions.

[0089] In existing nanoscale FP interferometry, the micron-level "drooping deflection" of the cantilever structure inside the probe under the action of gravity and centrifugal force can lead to fatal measurement baseline drift; while traditional multi-hole probes (such as five-hole probes) are bulky (usually greater than 8 mm) in order to obtain spatial distribution, and will produce strong aerodynamic blockage and wake interference when inserted into narrow flow channels.

[0090] This solution employs an extreme miniaturization architecture design from both physical statics and aerodynamics perspectives: Anti-sagging mechanical architecture: The internal movable unit features a unique three-in-one protective architecture of "lightweight + dual support + short cantilever". The dual support optimizes the force model from a "cantilever beam" to a "simply supported beam", strictly locking the deformation of internal components caused by centrifugal force or self-weight within the nanometer-level background noise range. This makes the cavity length change of the FP interferometer cavity uniquely and purely responds to external flow field parameters, completely eliminating the false signals introduced by internal mechanical "softening sagging".

[0091] Extremely low aerodynamic disturbance shape: Through a dynamic scanning strategy of "trading time for space", this solution covers the sensing range of traditional multi-hole probes with the rotation of a single probe, and this application successfully compresses the external shape limit of the probe into a spherical probe with a diameter of only about 3mm.

[0092] The preferred embodiments of this application have been described in detail above. However, this application is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this application.

[0093] Many other changes and modifications can be made without departing from the concept and scope of this application. It should be understood that this application is not limited to the specific embodiments, and the scope of this application is defined by the appended claims.

Claims

1. A rotating scanning based sapphire fiber F-P dual sensing microprobe, characterized in that: It includes an integrally molded spherical probe (1) and a connecting rod (2), the bottom of which is fastened to a micro transmission assembly (3); The spherical probe (1) has a top strip strain membrane (1-1) at the top, and the spherical probe (1) below the top strip strain membrane (1-1) has a top strain membrane cavity (1-2). The top strain membrane cavity (1-2) has a top optical sensor (1-3), and the bottom of the top optical sensor (1-3) is connected to a top-coupled sapphire optical fiber (1-7). The spherical probe (1) has a central strip strain membrane (1-4) arranged circumferentially around the spherical probe (1). The spherical probe (1) inside the central strip strain membrane (1-4) has a circumferentially arranged central strip strain membrane cavity (1-5). The rotating optical sensor (1-6) is located in the central strip strain membrane cavity (1-5). The tail of the rotating optical sensor (1-6) is connected to a rotating coupled sapphire optical fiber (1-8). The connecting rod (2) has a through hole (2-1) inside, and the top-coupled sapphire fiber (1-7) and the rotationally coupled sapphire fiber (1-8) both pass through the through hole (2-1). The micro transmission assembly (3) includes a housing (3-1), a motor (3-2), a cross-type coupling (3-3), a ceramic body boss (3-4), and a fiber optic data acquisition card (3-5). The motor (3-2) is fixed to the bottom inside the housing (3-1). The power output end of the motor (3-2) is connected to the cross-type coupling (3-3), and the other end of the cross-type coupling (3-3) is connected to the ceramic body boss (3-4). The fiber optic data acquisition card (3-5) is set at the top center of the ceramic body boss (3-4). The motor (3-2) is electrically connected to the fiber optic data acquisition card (3-5). The ends of the top-coupled sapphire fiber (1-7) and the rotationally coupled sapphire fiber (1-8) are respectively connected to and fixed to the fiber optic data acquisition card (3-5); The top optical sensor (1-3) and the top coupled sapphire optical fiber (1-7) constitute a reference measurement channel for acquiring reference signals; A rotating optical sensor (1-6) and a rotating coupled sapphire fiber (1-8) form a rotating scanning channel for scanning measurements at different circumferential positions of the central strip strain membrane (1-4). 2.The rotating scanning based sapphire fiber F-P dual-sensing microprobe according to claim 1, wherein: The connecting rod (2) has an arc-shaped opening (2-2) at its bottom. The micro transmission assembly (3) also includes an outer ceramic sleeve (3-6). The ceramic body boss (3-4) is fitted into the inner ring at the bottom of the outer ceramic sleeve (3-6). The top of the outer ceramic sleeve (3-6) protrudes through the outer shell (3-1). The top of the outer ceramic sleeve (3-6) passes through the arc-shaped opening (2-2) and is fixed in the through hole (2-1). 3.The rotating scanning based sapphire fiber F-P dual-sensing microprobe according to claim 2, wherein: The connecting rod (2) has two arc-shaped openings (2-2) at the bottom center, and the top of the outer ceramic sleeve (3-6) has two arc-shaped plugs, which are inserted into the two arc-shaped openings (2-2) respectively.

4. The sapphire fiber optic dual-sensor micro probe based on rotational scanning according to claim 2, characterized in that: The bottom edge of the connecting rod (2) is provided with a connecting annular protrusion (2-3), and the top edge of the outer shell (3-1) is provided with an annular groove. The annular protrusion (2-3) and the annular groove are interlocked.

5. The sapphire fiber optic dual-sensor micro probe based on rotational scanning according to claim 1, characterized in that: The diameter of the spherical probe (1) is 2.5~3.5mm, and the equivalent outer diameter of the rotating optical sensor (1-6) is... equivalent inner diameter Equivalent body length Equivalent overhang length equivalent quality Equivalent material elastic modulus .

6. The sapphire fiber optic FP dual-sensor micro probe based on rotational scanning according to claim 1, characterized in that: The motor (3-2) is an adaptive variable step size resampling motor.

7. The sapphire fiber optic dual-sensor micro probe based on rotational scanning according to claim 1, characterized in that: The rotary-coupled sapphire fiber (1-8) includes an integrally formed arc segment and a straight segment. The front end of the arc segment is connected to a rotary optical sensor (1-6), and the rear end of the straight segment is connected to a fiber optic data acquisition card (3-4).

8. The sapphire fiber optic dual-sensor micro probe based on rotational scanning according to claim 7, characterized in that: The rotating optical sensors (1-6) are supported by an upper and lower double support structure, a coaxial sleeve limiting structure, or a short cantilever plus radial limiting structure.

9. A measurement method based on a sapphire fiber optic FP dual-sensor micro probe with rotating scanning, characterized in that, Includes the following steps: Step 1: Install the sapphire fiber FP dual-sensor micro probe based on rotational scanning as described in any one of claims 1 to 8 into the flow field to be measured; Step 2: The motor (3-2) drives the rotating optical sensor (1-6) to scan and measure at different circumferential positions of the central strip strain membrane (1-4). At the same time, the top optical sensor (1-3) and the rotating optical sensor (1-6) transmit the collected data to the fiber optic data acquisition card (3-5) to form a voltage signal. Step 3: Voltage signal synchronization; The motor (3-2) feeds back the pulse-coded signal of its rotor position to the fiber optic data acquisition card (3-5) in real time, which serves as the spatial positioning and timestamp alignment reference for the interference data; Step 4: Reconstruct the interference spectrum from the synchronized voltage signal, extract the FP cavity length, and calculate the cavity length change. The original cavity length change was obtained by demodulating the rotating scanning channel. The change in raw cavity length demodulated from the reference measurement channel ; Step 5: Use dual-channel dynamic spatiotemporal differential compensation to compensate for nonlinear errors; utilize the original cavity length variation demodulated from the rotating scanning channel. The change in raw cavity length demodulated from the reference measurement channel The actual flow field deformation displacement after removing common-mode errors was calculated. ; Step 6: Calculate the actual flow field deformation displacement. The physical quantities are converted, and then the spatial distribution is reconstructed to obtain the pressure data of the flow field to be measured.

10. The measurement method of the sapphire fiber FP dual-sensor micro probe based on rotational scanning according to claim 9, characterized in that, The actual flow field deformation displacement The calculation formula is: ； In the formula: As temperature The variable structural coupling transfer coefficient.

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