A water-loaded multipoint optical fiber sensing system and application to large amphibious aircraft

Abstract

This utility model relates to the field of aircraft water load flight test technology, specifically to a large amphibious aircraft with a multi-point fiber optic sensing system for water load and its application. The system consists of several fiber optic sensors, with several fiber optic sensor arrays distributed on the aircraft's belly. Each sensor is connected to the aircraft's access port via a separate fiber optic pigtail, and then connected to armored fiber optic cables via fiber optic flanges and internal data acquisition equipment. This utility model can realize large-scale, multi-point real-time measurement of water load on amphibious aircraft. By utilizing fiber optic sensors and fiber optic signal transmission, it improves the measurement system's resistance to electromagnetic interference, high temperature, impact, high humidity, and high salinity, meeting the requirements of onshore and offshore aircraft testing.

Description

Technical Field

[0001] This utility model belongs to the field of adhesive structure design technology, specifically relating to a water load multi-point fiber optic sensing system and its application in a large amphibious aircraft. Background Technology

[0002] Amphibious aircraft are multi-functional aircraft capable of performing various complex missions such as ground surveillance, maritime rescue, and forest fire fighting. The complex mission environments necessitate that amphibious aircraft possess excellent water-landing capabilities to handle water-based takeoffs, landings, and taxiing. In particular, the seaworthiness of amphibious aircraft is a crucial technical indicator. Water impact loads have short durations and high peak values, easily causing structural damage, instrument malfunctions, control failures, and personnel injuries. Therefore, water load monitoring methods have significant engineering application value.

[0003] Existing methods for verifying water load primarily involve a combination of model testing and numerical simulation. In aircraft water load flight tests, sensors such as electrical pressure sensors and strain gauges are commonly used. Electrical pressure sensors are typically mounted on the model using a drilling method, while strain gauges are bonded to the fuselage surface. Since strain gauges cannot directly measure water impact loads, this method often introduces significant errors. Furthermore, the drilling method significantly impacts the structural strength of the aircraft and is difficult to implement for full-scale, multi-point measurements on a real aircraft. Simultaneously, electrical sensors suffer from poor anti-interference capabilities and insufficient resistance to humidity, salinity, and impact. Therefore, a large-scale, multi-point real-world water load measurement scheme for amphibious aircraft is urgently needed. Utility Model Content

[0004] This invention addresses the need for full-scale water load measurement of amphibious aircraft in both on-water and at-sea environments. It proposes a fiber-optic-based multi-point water load measurement system for amphibious aircraft. Benefiting from the advantages of fiber optics—small size, resistance to electromagnetic interference, flexibility, high temperature resistance, high humidity resistance, strong impact resistance, and high salinity resistance—this system enables full-scale, large-scale, multi-point sensing capabilities without affecting airframe strength, and full-scale multi-point measurement capabilities in extreme environments such as on-water and at sea. It solves the problems of existing drilling methods affecting airframe structural strength and the insufficient resistance of electrical sensors to humidity, salinity, and strong impact, as well as their susceptibility to environmental interference.

[0005] Technical solution: To achieve the above objectives, this utility model designs a multi-point fiber optic sensing system for water load. The system consists of several fiber optic sensors, with several fiber optic sensor arrays distributed on the belly of the aircraft. Each sensor is connected to the aircraft access port via a separate fiber optic pigtail, and is connected to an armored fiber optic cable via a fiber optic flange and then to an internal data acquisition device.

[0006] Furthermore, the fiber pigtail can be made of bend-resistant single-mode fiber or polyimide-coated bend-resistant single-mode fiber.

[0007] Furthermore, the optical fiber diameter is 250μm, and the operating wavelength is C-band.

[0008] Furthermore, the fiber optic sensor array adopts a multi-point arrangement, with each arrangement point serving as a measurement point.

[0009] Furthermore, at least 60% of the measuring points in the fiber optic sensor array are located before the amphibious aircraft enters the water to measure the maximum water impact load upon entry; the remaining measuring points are located after the water is disconnected.

[0010] Furthermore, the fiber optic sensor includes a temperature sensor and a pressure sensor, wherein the pressure sensor has a range of -100kPa to 1.5MPa and an accuracy of 0.5% FS, and the temperature sensor has a range of -80 to 200℃ and an accuracy of 0.5℃.

[0011] As a typical application of the multi-point fiber optic sensing system for water load designed above, this system is applied to large amphibious aircraft to realize real-time measurement of large-scale multi-point water load on amphibious aircraft.

[0012] Technical benefits: This invention enables real-time measurement of large-scale, multi-point water loads on amphibious aircraft. Utilizing fiber optic sensors and fiber optic signal transmission enhances the measurement system's resistance to electromagnetic interference, high temperatures, impacts, high humidity, and high salinity, meeting the requirements for real-world testing on water and at sea. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the multi-point fiber optic sensing system for water load of a large amphibious aircraft according to this utility model.

[0014] Among them, 1-fiber optic sensor array, 2-aircraft access point. Detailed Implementation

[0015] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0016] The design of a multi-point fiber optic sensing system for water load on large amphibious aircraft involves the installation of numerous sensors on the aircraft's surface. A multi-point arrangement is used, distributing several fiber optic sensor arrays across the aircraft's underside. Fixing methods include, but are not limited to, adhesive bonding and internal embedding. Theoretical simulations are used to determine the measurement range of the fiber optic sensors, as well as their installation locations and quantities in different areas, based on the magnitude of the water load and its spatiotemporal variation rate. Here, the fiber optic sensors primarily refer to fiber optic point pressure sensors. The typical fiber optic sensor's encapsulation thickness should not exceed 1mm. Depending on the water load, the pressure range can be -100kPa to 1MPa, -100kPa to 1.5MPa, or -100kPa to 2MPa, with a measurement accuracy of no less than 0.5% FS. The number of sensors ranges from 1 to 1000, depending on actual testing requirements.

[0017] Sensor wiring layout and equipment connection. Since the equipment is located inside the aircraft, the sensor fiber optic cables need to be routed into the fuselage. The fiber optic cable path is determined based on the location of the fiber optic connector. Here, the fiber optic pigtail can be selected from bend-resistant single-mode, polyimide-coated bend-resistant single-mode fiber with a diameter of 250μm and operating in the C-band.

[0018] The device's data acquisition is synchronized with the clock. Data acquisition is achieved through a fiber optic demodulation system, and the device also synchronizes with other sensor data by connecting to the aircraft's GPS signal. Typical data acquisition rates here are 10kHz, 20kHz, and 30kHz. The device should be equipped with electromagnetic interference and vibration damping devices.

[0019] See appendix Figure 1This utility model specifically designs a multi-point fiber optic sensing system for water loads on a large amphibious aircraft, comprising a fiber optic sensor array 1. Each sensor in the array collects signals via optical fibers, which are then converged at the aircraft access port 2. These signals are connected to armored optical fibers via fiber optic flanges and then to internal data acquisition equipment. In a typical example, a multi-point measurement method based on 16 measuring points requires 12 fiber optic pressure sensors and 4 fiber optic temperature sensors. Each sensor is connected to the aircraft access port via a separate fiber optic pigtail, and then connected to armored optical fibers via fiber optic flanges and finally to internal data acquisition equipment. During the implementation, 10 measuring points were located before the amphibious aircraft entered the water to measure the maximum water impact load upon entry. These included 2 temperature sensors and 8 pressure sensors. The pressure sensors had a range of -100 kPa to 1.5 MPa and an accuracy of 0.5% FS, while the temperature sensors had a range of -80 to 200°C and an accuracy of 0.5°C. Additionally, 6 measuring points were located after the water entered the water, including 2 temperature sensors and 4 pressure sensors. The pressure sensors had a range of -100 kPa to 1 MPa and an accuracy of 0.5% FS, while the temperature sensors had a range of -80 to 200°C and an accuracy of 0.5°C.

[0020] The specific implementation method needs to be adjusted according to different water load flight test plans. There are multiple ways to achieve this. The final implementation result should satisfy the relationship between the sensor installation method, range, accuracy and system test accuracy mentioned above.

[0021] The above specific embodiments or examples are only used to explain the technical solutions of this utility model and are not intended to limit this utility model. Parts not described in detail are considered as conventional technical means in the field. Those skilled in the art should understand that, based on the design concept of this application, adaptive modifications can be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the various embodiments of this utility model.

Claims

1. A multi-point fiber optic sensing system for water load, characterized in that, The system consists of several fiber optic sensors, with several fiber optic sensor arrays distributed on the belly of the aircraft; each sensor is connected to the aircraft access port via a separate fiber optic pigtail, and is connected to the armored fiber optic cable and the internal data acquisition equipment via a fiber optic flange.

2. The multi-point fiber optic sensing system for water load as described in claim 1, characterized in that, The fiber optic pigtail can be made of bend-resistant single-mode fiber or polyimide-coated bend-resistant single-mode fiber.

3. The multi-point fiber optic sensing system for water load as described in claim 2, characterized in that, The optical fiber has a diameter of 250μm and operates in the C-band.

4. The multi-point fiber optic sensing system for water load as described in claim 1, characterized in that, The fiber optic sensor array adopts a multi-point arrangement, with each arrangement point serving as a measurement point.

5. The multi-point fiber optic sensing system for water load as described in claim 4, characterized in that, No less than 60% of the measuring points in the fiber optic sensor array are located before the amphibious aircraft enters the water to measure the maximum water impact load upon entry; the remaining measuring points are located after the water is disconnected.

6. The multi-point fiber optic sensing system for water load as described in claim 5, characterized in that, The fiber optic sensor includes a temperature sensor and a pressure sensor. The pressure sensor has a range of -100 kPa to 1.5 MPa and an accuracy of 0.5% FS. The temperature sensor has a range of -80 to 200℃ and an accuracy of 0.5℃.

7. A large amphibious aircraft, characterized in that, The aircraft has a water load multi-point fiber optic sensing system as described in any one of claims 1 to 6.

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