Wing real-time deformation load inversion method based on fiber grating strain sensor

Abstract

The invention relates to a real-time wing deformation load inversion method based on fiber grating strain sensors, provides a real-time wing deformation load measurement and analysis method based on the fiber grating strain sensors, and solves the key technical problem of real-time analysis and calculation of fiber grating strain measurement results. A fiber bragg grating temperature sensor is connected in series at the tail end of the sensor, real-time strain of each measurement point is obtained according to measurement results of the fiber bragg grating strain sensor and the temperature sensor, and real-time deformation of the wing is obtained through a strain inversion deformation algorithm; and obtaining the real-time load of the wing through a strain inversion load algorithm.

Description

Technical Field

[0001] The invention relates to a wing real-time deformation load inversion method based on a fiber grating strain sensor, belonging to the technical field of optical fiber sensing. Background Art

[0002] Deformation and load measurement is one of the important means to analyze the stress state of aircraft parts or structures, verify the correctness of the design, and determine the load condition of the whole aircraft during actual operation. It is of great significance for structural damage identification and health monitoring. The intelligent health monitoring system of aircraft composite structures can meet the needs of continuous monitoring of flight loads and monitoring of aircraft structural damage, provide favorable data support for quantifying the health status of aircraft, reduce the frequency and cost of maintenance inspections, improve the safety and reliability of aircraft, and ultimately extend the operating life cycle of aircraft.

[0003] At present, the aircraft composite structure load and damage monitoring system based on fiber grating sensors has been applied to a series of ground tests and designs. The results of many tests have shown that the fiber grating sensing system can effectively monitor the local damage of the aircraft composite structure. In 2013, Airbus announced a plan to install fiber grating sensing monitoring systems on all new aircraft in the future. However, in terms of detecting overall damage to aircraft structures, since the main measurement parameter of fiber grating sensors is strain, it is still necessary to establish a reliable method to link the measured strain with the aircraft structure parameters (deformation and load), so as to more reliably monitor the overall health of the aircraft structure. Summary of the invention

[0004] The technical problem solved by the present invention is: in view of the problem that the existing technology lacks means for associating measured strain with aircraft structural parameters, a real-time deformation load inversion method for a wing based on a fiber grating strain sensor is proposed.

[0005] The present invention solves the above technical problems by the following technical solutions:

[0006] A method for inverting real-time deformation load of a wing based on a fiber grating strain sensor, comprising:

[0007] Measuring points are set on the wing surface, and fiber Bragg grating strain sensors connected in series are attached to each measuring point;

[0008] A fiber Bragg grating temperature sensor is connected in series at the end of each fiber Bragg grating strain sensor;

[0009] The measurement results of fiber Bragg grating strain sensor and fiber Bragg grating temperature sensor are collected to obtain the real-time strain and real-time temperature of each measuring point. The real-time deformation of the wing is calculated by the strain inversion deformation algorithm, and the real-time load of the wing is calculated by the strain inversion load algorithm.

[0010] The fiber Bragg grating strain sensor adopts a fiber Bragg grating strain sensor, and the wavelength measurement result is Δλ 1 , the wavelength sensitivity coefficient is C 1 .

[0011] The spacing between the measuring points is set to Δl, the number of measuring points is n, and the spacing and number of measuring points are selected and determined according to the wing structure.

[0012] After the fiber Bragg grating strain sensors are connected in series, the connection spacing of the fiber Bragg grating measuring points in series and the number of the fiber Bragg grating strain sensors in series correspond to the measuring points.

[0013] The fiber grating strain sensor is attached to the corresponding measuring point on the outer surface of the wing along the length direction of the wing by adhesive.

[0014] The fiber Bragg grating strain sensor is connected in series with a fiber Bragg grating temperature sensor at the end for temperature compensation. The temperature compensation is calculated as follows:

[0015]

[0016] Where ε is the compensation temperature value.

[0017] The fiber Bragg grating temperature sensor is a fiber Bragg grating temperature sensor, and the wavelength measurement result is Δλ 2 , the wavelength sensitivity coefficient is C 2 .

[0018] The setting parameters of each measuring point are:

[0019] The distance from the measuring point to the wing root is x i ;

[0020] The real-time strain at the measuring point after temperature compensation is ε(x i );

[0021] The distance from the measuring point to the neutral axis of the wing is c(x i ).

[0022] The strain inversion deformation algorithm is:

[0023] Computer Wing in X i The tilt angle tanθ of the measuring point i ;

[0024] Computer Wing in X i The total deformation y of the measuring point i ,in:

[0025] Wing at x i The tilt angle tanθ of the measuring pointi for

[0026]

[0027] Wing at x i Total deformation y of the measuring point i for

[0028]

[0029] The variable inversion load algorithm is:

[0030] Computer Wing in X i The strength of the measuring point is calculated based on the strength value. i Load value at the measuring point

[0031]

[0032] Where P i is the load value at measuring point i.

[0033] The advantages of the present invention compared with the prior art are:

[0034] (1) The present invention provides a real-time deformation load inversion method for a wing based on a fiber Bragg grating strain sensor. The fiber Bragg grating sensor principle is applied to demodulate the central wavelength and intensity of each fiber Bragg grating along the length direction of the optical fiber to obtain large-capacity light wave parameter information. Multiple measurement points are set and each central wavelength of the optical fiber sensor is calculated and processed using a statistical method, thereby obtaining the deformation load information of the wing in real time, with a fast real-time response speed.

[0035] (2) The present invention upgrades the deformation measurement method from point sensing to distributed sensing, realizes high-density deformation load measurement within the full range, significantly improves the measurement accuracy and coverage, solves the key technical difficulties of real-time measurement and analysis of wing deformation load, and can meet the future needs of real-time deformation load perception and real-time data output of wings. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A flow chart of a method for inverting the real-time deformation load of a wing based on a fiber Bragg grating strain sensor provided by the present invention;

[0037] Figure 2 This is a schematic diagram of the sensor layout provided by the present invention. DETAILED DESCRIPTION

[0038] A method for inverting the real-time deformation load of a wing based on a fiber Bragg grating strain sensor is provided. The method solves the key technical problem of real-time analysis and calculation of the fiber Bragg grating strain measurement results. The method comprises: a fiber Bragg grating strain sensor is attached in series to the wing surface, a fiber Bragg grating temperature sensor is connected in series to the end of the sensor, the real-time strain of each measuring point is obtained according to the measurement results of the fiber Bragg grating strain sensor and the temperature sensor, the real-time deformation of the wing is obtained by a strain inversion deformation algorithm, and the real-time load of the wing is obtained by a strain inversion load algorithm.

[0039] The real-time deformation load inversion method of the wing based on the fiber Bragg grating strain sensor includes the following steps:

[0040] Measuring points are set on the wing surface, and fiber Bragg grating strain sensors connected in series are attached to each measuring point;

[0041] A fiber Bragg grating temperature sensor is connected in series at the end of each fiber Bragg grating strain sensor;

[0042] The measurement results of fiber Bragg grating strain sensor and fiber Bragg grating temperature sensor are collected to obtain the real-time strain and real-time temperature of each measuring point. The real-time deformation of the wing is calculated by the strain inversion deformation algorithm, and the real-time load of the wing is calculated by the strain inversion load algorithm.

[0043] The fiber Bragg grating strain sensor uses a fiber Bragg grating strain sensor, and the wavelength measurement result is Δλ 1 , the wavelength sensitivity coefficient is C 1 .

[0044] The spacing between each measuring point is set to Δl, the number of measuring points is set to n, and the spacing and number of each measuring point are selected and determined according to the wing structure.

[0045] After the fiber Bragg grating strain sensors are connected in series, the connection spacing of the fiber Bragg grating measuring points in series and the number of the fiber Bragg grating strain sensors in series correspond to the measuring points.

[0046] The fiber grating strain sensor is attached to the corresponding measuring point on the outer surface of the wing along the length direction of the wing by adhesive.

[0047] A fiber Bragg grating temperature sensor is connected in series at the end of the fiber Bragg grating strain sensor for temperature compensation. The temperature compensation calculation method is:

[0048]

[0049] Where ε is the compensation temperature value.

[0050] The fiber Bragg grating temperature sensor is a fiber Bragg grating temperature sensor, and the wavelength measurement result is Δλ 2, the wavelength sensitivity coefficient is C 2 .

[0051] The setting parameters of each measuring point are:

[0052] The distance from the measuring point to the wing root is x i ;

[0053] The real-time strain at the measuring point after temperature compensation is ε(x i );

[0054] The distance from the measuring point to the neutral axis of the wing is c(x i ).

[0055] The strain inversion deformation algorithm is:

[0056] Computer Wing in X i The tilt angle tanθ of the measuring point i ;

[0057] Computer Wing in X i The total deformation y of the measuring point i ,in:

[0058] Wing at x i The tilt angle tanθ of the measuring point i for

[0059]

[0060] Wing at x i Total deformation y of the measuring point i for

[0061]

[0062] The variable inversion load algorithm is:

[0063] Computer Wing in X i The strength of the measuring point is calculated based on the strength value. i Load value at the measuring point

[0064]

[0065] Where P i is the load value at measuring point i.

[0066] The following is further described in conjunction with the accompanying drawings and preferred embodiments of the specification:

[0067] In the current embodiment, if Figure 1 As shown, in this embodiment, the real-time deformation load measurement and analysis method of the wing based on the fiber Bragg grating strain sensor includes:

[0068] Step 101, affixing serially connected fiber Bragg grating strain sensors to the wing surface.

[0069] In this embodiment, the fiber Bragg grating strain sensor may refer to a fiber Bragg grating strain sensor, and the wavelength measurement result is Δλ 1 , the wavelength sensitivity coefficient is C 1 .

[0070] like Figure 2 As shown in the figure, the fiber Bragg grating strain sensor is attached to the outer side of the wing, the spacing between the fiber Bragg grating measuring points in series is Δl, and the number of fiber Bragg grating strain sensors in series is n. The distance from each measuring point of the fiber Bragg grating strain sensor to the root of the wing is x; the real-time strain after temperature compensation is ε(x); and the distance to the neutral axis of the wing is c(x).

[0071] Step 102: A fiber grating temperature sensor is connected in series at the end of the sensor.

[0072] Fiber Bragg grating temperature sensor can be a fiber Bragg grating temperature sensor, and the wavelength measurement result is Δλ 2 , the wavelength sensitivity coefficient is C 2 .

[0073] Step 103: acquiring the real-time strain of each measuring point according to the measurement results of the fiber grating strain sensor and the temperature sensor.

[0074] According to the measurement results of each fiber Bragg grating strain sensor and the measurement results of the fiber Bragg grating temperature sensor, the strain of each measuring point is calculated as follows:

[0075] Step 104, obtaining the real-time deformation of the wing by using a strain inversion deformation algorithm;

[0076] Computing wing real-time deformation i The expression is:

[0077]

[0078] Step 105, obtaining the real-time load of the wing by using a strain inversion load algorithm.

[0079] Compute wing real-time load P i The expression is:

[0080]

[0081] In summary, the real-time deformation load measurement and analysis method of the wing based on the fiber Bragg grating strain sensor of the present invention uses the fiber Bragg grating strain measurement results, and obtains the information of the distributed deformation load of the wing through the strain inversion deformation algorithm and the strain inversion load algorithm. This method has higher safety, higher measurement accuracy, and a larger measurement range. It is lighter, more convenient, and safer than other electrical sensors. This improvement in accuracy, increase in coverage, and improvement in safety will play a vital role in the future development of the field of aircraft structure monitoring.

[0082] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

[0083] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A method for real-time deformation load inversion of a wing based on a fiber Bragg grating strain sensor, characterized in that include: Measuring points are set on the wing surface, and fiber Bragg grating strain sensors connected in series are attached to each measuring point; A fiber Bragg grating temperature sensor is connected in series at the end of each fiber Bragg grating strain sensor; The measurement results of fiber Bragg grating strain sensor and fiber Bragg grating temperature sensor are collected to obtain the real-time strain and real-time temperature of each measuring point. The real-time deformation of the wing is calculated by the strain inversion deformation algorithm, and the real-time load of the wing is calculated by the strain inversion load algorithm.

2. The method for real-time deformation load inversion of a wing based on a fiber Bragg grating strain sensor according to claim 1, characterized in that: The fiber grating strain sensor adopts a Bragg fiber grating strain sensor, the wavelength measurement result is Δλ1, and the wavelength sensitivity coefficient is C1.

3. The method for real-time deformation load inversion of a wing based on a fiber Bragg grating strain sensor according to claim 1, characterized in that: The spacing between the measuring points is set to Δl, the number of measuring points is n, and the spacing and number of measuring points are selected and determined according to the wing structure.

4. The method for real-time deformation load inversion of a wing based on a fiber Bragg grating strain sensor according to claim 3 is characterized by: After the fiber Bragg grating strain sensors are connected in series, the connection spacing of the fiber Bragg grating measuring points in series and the number of the fiber Bragg grating strain sensors in series correspond to the measuring points.

5. The method for real-time deformation load inversion of a wing based on a fiber Bragg grating strain sensor according to claim 4, characterized in that: The fiber grating strain sensor is attached to the corresponding measuring point on the outer surface of the wing along the length direction of the wing by adhesive.

6. The method for real-time deformation load inversion of a wing based on a fiber Bragg grating strain sensor according to claim 4, characterized in that: The fiber Bragg grating strain sensor is connected in series with a fiber Bragg grating temperature sensor at the end for temperature compensation. The temperature compensation is calculated as follows: Where ε is the compensation temperature value.

7. The method for real-time deformation load inversion of a wing based on a fiber Bragg grating strain sensor according to claim 6, characterized in that: The fiber grating temperature sensor is a Bragg fiber grating temperature sensor, the wavelength measurement result is Δλ2, and the wavelength sensitivity coefficient is C2.

8. The method for real-time deformation load inversion of a wing based on a fiber Bragg grating strain sensor according to claim 6, characterized in that: The setting parameters of each measuring point are: The distance from the measuring point to the wing root is x i ; The real-time strain at the measuring point after temperature compensation is ε(x i ); The distance from the measuring point to the neutral axis of the wing is c(x i ).

9. The method for real-time deformation load inversion of a wing based on a fiber Bragg grating strain sensor according to claim 8, characterized in that: The strain inversion deformation algorithm is: Computer Wing in X i The tilt angle tanθ of the measuring point i ; Computer Wing in X i The total deformation y of the measuring point i ,in: Wing at x i The tilt angle tanθ of the measuring point i for Wing at x i Total deformation y of the measuring point i for 10. The method for real-time deformation load inversion of a wing based on a fiber Bragg grating strain sensor according to claim 9, characterized in that: The variable inversion load algorithm is: Computer Wing in X i The strength of the measuring point is calculated based on the strength value. i Load value at the measuring point Where P i is the load value at measuring point i.

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