Collision identification research method based on optical fiber FP sensibilization

Abstract

The invention relates to the technical field of optical fiber sensing and collision identification, and discloses a novel optical fiber FP (Fabry-Perot) sensor which comprises a single-mode optical fiber, metal gold and a PETP (Polyethylene Terephthalate) film, the single-mode optical fiber is connected with the metal gold through epoxy resin, and the metal gold is deposited on the surface of the PETP film through the metal chromium; the PETP film is made of polyethylene terephthalate plastic; comprising the following steps: S1, adopting a PETP film as a metal deposition substrate; s2, metal chromium with a certain thickness is deposited on the surface of the thin film through the vacuum evaporation technology; and S3, metal gold with a certain thickness is deposited outside the chromium-plated PETP film. The corrosion-resistant metal gold is used for improving the optical reflectivity, and the optical fiber sensor has the advantages of corrosion resistance, light weight, easiness in integration and the like, so that when the optical fiber sensor is used for collision identification of spacecrafts, the sensitivity and speed of collision identification are improved, and a more reliable basis is provided for collision early warning and safety protection.

Description

Technical Field

[0001] The present invention relates to the field of optical fiber sensing and collision recognition technology, and in particular to a collision recognition research method based on optical fiber FP sensitivity enhancement. Background Art

[0002] In today's era of rapid technological development, collision recognition technology plays a vital role in many fields. Whether it is the safety monitoring of aircraft in the aerospace field, the collision warning of vehicles in the transportation field, or the operating status detection of equipment in industrial production, efficient and accurate collision perception methods are indispensable.

[0003] Traditional collision sensing technologies mainly include mechanical structure-based sensors and single optical or acoustic sensors. Mechanical structure collision sensors are usually large in size and inconvenient to install and maintain. Moreover, their sensitivity is limited, and they may not be able to accurately sense and identify small collisions in a timely manner. In addition, mechanical sensors are easily affected by environmental factors such as temperature, humidity, vibration, etc., which will reduce the accuracy and reliability of their measurements.

[0004] Although the single optical collision perception method has the advantages of fast response speed and high accuracy, it also has some problems in practical applications. For example, optical sensors are easily interfered by light, such as strong light exposure, shadow occlusion, etc., which may lead to misjudgment or missed collision events. At the same time, the cost of optical sensors is relatively high, which limits their widespread application in some fields. Acoustic collision recognition methods also have their limitations. In complex noise environments, the accuracy of acoustic sensors will be greatly reduced.

[0005] Moreover, acoustic sensors have a weak response to low-frequency collisions and cannot meet the needs of certain specific scenarios. With the continuous development of fiber optic technology, fiber optic sensors are gradually emerging in the field of collision perception. Fiber optic sensors have the advantages of small size, light weight, anti-electromagnetic interference, high sensitivity, etc., and can adapt to various harsh environmental conditions. However, the existing fiber optic collision recognition technology still cannot meet the requirements of high precision in some cases. For example, in the detection of weak collision signals, the sensitivity of fiber optic sensors needs to be improved.

[0006] To this end, those skilled in the art provide a collision identification research method based on optical fiber FP sensitivity enhancement to solve the problems raised in the above background technology. Summary of the invention

[0007] In view of the deficiencies in the prior art, the present invention provides a collision identification research method based on optical fiber FP sensitivity enhancement, which solves the problems of low accuracy and large volume.

[0008] To achieve the above objectives, the present invention is implemented through the following technical solutions: a new type of optical fiber FP sensor, including: single-mode optical fiber, metal gold, PETP film;

[0009] The single-mode optical fiber is connected to the metal gold through epoxy resin, and the metal gold is deposited on the surface of the PETP film through metal chromium.

[0010] Preferably, the PETP film is made of polyethylene terephthalate plastic.

[0011] A collision identification research method based on optical fiber FP sensitization, according to a new optical fiber FP sensor, includes the following steps:

[0012] S1, using PETP film as the metal deposition substrate;

[0013] S2, using vacuum evaporation technology to deposit a certain thickness of metal chromium on the surface of the film;

[0014] S3, then depositing a certain thickness of metal gold outside the chrome-plated PETP film;

[0015] S4, turning the PETP film over to the non-metal-plated surface, and depositing chromium and gold reflective layers;

[0016] S5. After the metal deposition is completed, it is cut into the desired shape;

[0017] S6. Design a packaging structure with tolerance capability;

[0018] S7, vertically and non-destructively assemble the optical fiber probe into the through hole of the ceramic substrate;

[0019] S8, using dry transfer to peel off the PETP film and closely adhere it to the ceramic substrate;

[0020] S9, accurately adjust the position of the optical fiber probe, use epoxy resin to fix the single-mode optical fiber and the ceramic substrate, and complete the production of the optical fiber FP sensor;

[0021] S10. Fix the fiber optic FP sensor on the surface of the spacecraft using epoxy resin.

[0022] Preferably, in the step S6, a corrosion-resistant ceramic ferrule is placed inside the packaging structure to protect and fix the position of the optical fiber FP sensor.

[0023] Preferably, in the step S2, the metal chromium is deposited in a circular shape.

[0024] The present invention provides a research method for collision identification based on optical fiber FP sensitivity enhancement, which has the following beneficial effects:

[0025] The present invention utilizes corrosion-resistant metal gold to improve optical reflectivity. At the same time, due to the advantages of optical fiber sensors such as corrosion resistance, light weight and easy integration, they are used for collision identification of spacecraft, thereby improving the sensitivity and speed of collision identification and providing a more reliable basis for collision warning and safety protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The design structure of the optical fiber FP sensor;

[0027] Figure 2 It is a schematic diagram of a collision recognition device of an optical fiber FP sensor;

[0028] Figure 3 This is a schematic diagram of the ultrasonic Lamb signal acting on the optical fiber FP sensor;

[0029] Figure 4 It is a diagram of the method steps of the present invention.

[0030] Among them, 1. Single-mode optical fiber; 2. Metallic gold; 3. PETP film. DETAILED DESCRIPTION

[0031] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] Example:

[0033] See also Figure 1 , Figure 3 A novel optical fiber FP sensor includes a single-mode optical fiber 1, metal gold 2, and a PETP film 3. Metal chromium is used to connect the metal gold 2 and the PETP film 3 on both sides. In order not to affect the transmittance, the metal chromium is deposited by vacuum evaporation, and the thickness of the metal chromium is nanometer level.

[0034] The single-mode optical fiber 1 and the metal gold 2 are connected by epoxy resin. Since epoxy resin has a high light transmittance, there is still a certain amount of reflected light after reflection by two layers of metal gold 2, which will not affect the interference spectrum in the single-mode optical fiber 1.

[0035] See also Figure 1 When light is transmitted in the single-mode optical fiber 1, part of the light is reflected from the end face of the single-mode optical fiber 1, and the other part of the light enters the FP cavity, and is reflected by the metal gold 2 and then incident back to the single-mode optical fiber 1. Since there is an optical path difference between the two reflected lights, there is an interference spectrum in the single-mode optical fiber 1. If the cavity thickness is equal to an integer multiple of the laser wavelength, the transmittance is maximum and the reflectivity is minimum, thus generating a trough in the reflection spectrum.

[0036] The fiber FP sensor causes the optical path difference of the transmission beam to change through the effect of the ultrasonic Lamb signal on the FP cavity, which in turn causes the phase difference to change. This is phase modulation and has high sensitivity.

[0037] The light emitted by the laser reaches the optical fiber FP sensor after passing through the circulator, and is reflected on the two reflection surfaces of the FP cavity. The reflected light intensity is:

[0038] I1=IR1

[0039] I2=I(1-R1) 2 R2

[0040] Where I is the light intensity reaching the sensor, and R1 and R2 are the reflectivities of the two reflective surfaces respectively.

[0041] The total reflected light intensity of a single-mode optical fiber is:

[0042]

[0043] Among them, R1 and R2 are the reflectivities of the two reflection surfaces of the FP cavity, n0 is the refractive index of light in the PETP film, L is the length of the FP cavity, and I0 is the light intensity when the incident wavelength is λ.

[0044] When the ultrasonic Lamb acts on the optical fiber FP sensor, the FP cavity will be deformed and its reflection spectrum will shift.

[0045] When the elastic deformation of the FP cavity is less than 30% of the thickness of the FP cavity, the deformation is proportional to the pressure;

[0046] For the central area of ​​the FP cavity, the maximum deformation is:

[0047]

[0048] Where r and d are the effective radius and thickness of the FP cavity, u and E are the Poisson's ratio and Young's modulus of the FP cavity, and P is the pressure acting on the FP cavity.

[0049] When the ultrasonic wave acts on the FP cavity, it causes the cavity to vibrate, causing the FP cavity length to oscillate back and forth within the linear range of the interference spectrum, and then the conversion of ultrasonic Lamb and light intensity signals is obtained;

[0050] When the FP cavity length is at the orthogonal working point Q, its light intensity change rate is the largest, that is, the sensor sensitivity is the highest;

[0051] The thickness of the metal gold 2 is achieved at the nanometer level by vacuum evaporation, thereby improving the light transmittance of the metal gold 2 and thereby increasing the intensity of interference light in the single-mode optical fiber;

[0052] The change of the output interference signal is detected to realize the recognition of the collision signal.

[0053] See also Figure 2 ,The collision recognition method uses ultrasonic excitation equipment to simulate the Lamb signal generated by collision. ,The simulation experimental equipment is as follows: tunable laser, circulator, photoelectric converter, oscilloscope, fiber FP sensor, ultrasonic probe, ultrasonic generator, and control computer.

[0054] The interference light after the ultrasonic Lamb signal is acted on enters the circulator through the single-mode optical fiber 1, and the optical signal is converted into an electrical signal by a photoelectric converter connected to the circulator, and finally the signal is identified by an oscilloscope.

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

Claims

1. A novel optical fiber FP sensor, characterized in that: include: Single-mode optical fiber (1), metallic gold (2), PETP film (3); The single-mode optical fiber (1) is connected to the metal gold (2) via epoxy resin, and the metal gold (2) is deposited on the surface of the PETP film (3) via metal chromium.

2. A novel optical fiber FP sensor according to claim 1, characterized in that: The PETP film (3) is made of polyethylene terephthalate plastic.

3. A research method for collision identification based on optical fiber FP sensitization, according to a novel optical fiber FP sensor according to any one of claims 1-2, characterized in that: The following steps are involved: S1, using PETP film (3) as a metal deposition substrate; S2, using vacuum evaporation technology to deposit a certain thickness of metal chromium on the surface of the film; S3, then depositing a certain thickness of metal gold (2) outside the chrome-plated PETP film (3); S4, turning the PETP film (3) over to the non-metal-plated side, and depositing a reflective layer of chromium and gold; S5. After the metal deposition is completed, it is cut into the desired shape; S6. Design a packaging structure with tolerance capability; S7, vertically and non-destructively assemble the optical fiber probe into the through hole of the ceramic substrate; S8, peeling off the PETP film (3) by dry transfer and making it closely fit with the ceramic substrate; S9, accurately adjust the position of the optical fiber probe, use epoxy resin to fix the single-mode optical fiber (1) and the ceramic substrate, and complete the production of the optical fiber FP sensor; S10. Fix the fiber optic FP sensor on the surface of the spacecraft using epoxy resin.

4. A collision identification research method based on optical fiber FP sensitization according to claim 3, characterized in that: In the step S6, a corrosion-resistant ceramic ferrule is placed inside the packaging structure to protect and fix the position of the optical fiber FP sensor.

5. The method for collision identification based on optical fiber FP sensitization according to claim 3 is characterized in that: In the step S2, the metal chromium is deposited in a circular manner.

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