Airborne stand-alone service life monitoring sensing data acquisition device

Abstract

The utility model discloses an airborne stand-alone service life monitoring sensing data acquisition device, which relates to the technical field of aviation and comprises a plurality of optical fiber sensors, a host and optical fibers. The optical fiber sensors are distributed and fixed on an aircraft structural member and connected with the host through optical fibers; the host comprises a shell, a main control board and a plurality of interfaces; the main control board is arranged in the shell, and the interface is arranged on one side face of the shell and connected with the main control board. An optical fiber connection interface; the main control board comprises a preprocessing board, a power board and a control board; the preprocessing board is connected with the interface and the control board. The power board is connected with the preprocessing board and the control board. According to the utility model, single-machine detection data can be accurately acquired in real time, and single-machine service life monitoring can be realized.

Description

Technical Field

[0001] The utility model relates to the field of aviation technology, and more particularly to an airborne single-machine life monitoring sensor data acquisition device. Background Art

[0002] With the continuous development of aviation technology, aircraft safety and reliability are receiving increasing attention. Aircraft structural inspection, maintenance, and safety assurance technologies are also evolving from preventative maintenance (preventative maintenance) based on calendar time and flight cycles to condition-based maintenance (CBM) based on structural condition monitoring data. This aims to better ensure the structural integrity, functionality, safety, and reliability of aircraft throughout their lifecycle, while reducing system maintenance costs.

[0003] Aircraft life management has evolved from "fleet life management" to "single-aircraft life management." Fleet management treats a fleet of aircraft of the same model as a whole. Based on the results of full-scale fatigue testing under a benchmark load spectrum and durability / damage tolerance analysis of key structural components, it develops a fleet service life and maintenance outline, employing unified principles and methods for implementation. However, this approach suffers from two shortcomings: it fails to guarantee the maximum flight safety of each aircraft; and the fleet life is often lower than the actual lifespan of most aircraft, resulting in a waste of resources. Therefore, single-aircraft life management manages the lifespan of each aircraft in the fleet, avoiding potential safety hazards arising from deviations from actual usage, ensuring flight safety, and avoiding waste caused by fleet management. However, existing single-aircraft life management often relies on traditional manual monitoring, resulting in low monitoring reliability, inefficient data collection, and high costs.

[0004] Therefore, how to achieve real-time and accurate data collection in single-machine life monitoring is an urgent problem that technicians in this field need to solve. Utility Model Content

[0005] In view of this, the utility model provides an airborne single-machine life monitoring sensor data acquisition device, which can collect single-machine detection data in real time and accurately, and helps to realize single-machine life monitoring.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] An onboard single-machine life monitoring sensor data acquisition device comprises a plurality of fiber optic sensors, a host computer and optical fibers; the fiber optic sensors are distributed and fixed on aircraft structural components and connected to the host computer via the optical fibers; the host computer comprises a housing, a main control board and a plurality of interfaces; the main control board is disposed within the housing, the interfaces are disposed on a side of the housing and connected to the main control board; the optical fibers are connected to the interfaces; the main control board comprises a preprocessing board, a power supply board and a control board; the preprocessing board is connected to the interfaces and the control board, and the power supply board is connected to the preprocessing board and the control board.

[0008] Preferably, the pre-processing board includes a connected T-type filter and an RFI low-pass filter circuit; the T-type filter and the RFI low-pass filter circuit are both connected to the interface, and the T-type filter is connected to the power supply board.

[0009] Preferably, the power supply board includes a filter, a DC isolator and a voltage conversion module; the input end of the filter is connected to the interface, the output end of the filter is connected to the input end of the DC isolator, and the output end of the DC isolator is connected to the T-type filter of the preprocessing board and the control board through a voltage conversion unit.

[0010] Preferably, the control panel includes a tunable narrowband light source, a wavelength calibration module, a photodetector module, a signal processing module, and a data acquisition and control module connected in sequence; wherein the tunable narrowband light source includes an ASE light source, an optical attenuator, a tunable FP filter and an optical splitter connected in sequence, the optical splitter is connected to the interface, and the tunable FP filter is connected to the wavelength calibration module; the photodetector module includes a photoelectric detection circuit, a zeroing circuit, an amplification circuit and a filtering circuit connected in sequence, and the photoelectric detection circuit is connected to the interface; the signal processing circuit includes a modulation and demodulation circuit; the data acquisition and control module includes a data acquisition card, an analog-to-digital converter, a controller and a network port transmission module connected in sequence, and the network port transmission module is connected to the interface.

[0011] The technical effect of the above technical solution is that the tunable narrowband light is evenly divided into 8 paths through the optical splitter to achieve the purpose of multi-channel demodulation. The optical splitter can divide the optical path into multiple parts, which allows the system to simultaneously demodulate sensors of multiple channels without channel switching time, thereby improving the demodulation rate; the power of the ASE light source is 10dBm-13dBm, that is, 10-20mW, and the input power of the tunable FP filter is 9mW. The power of the light source is greater than the maximum input power of the tunable FP filter, so it is necessary to add an optical attenuator between the two to attenuate the optical power of the light source to a power range acceptable to the tunable FP filter.

[0012] Preferably, the RFI low-pass filter circuit includes a common-mode filter circuit and a differential-mode filter circuit.

[0013] Preferably, the wavelength calibration module includes a FP etalon.

[0014] Preferably, the data acquisition card is an N16361 data acquisition card.

[0015] Preferably, the optical fiber sensor includes a strain sensor and a temperature sensor, etc., all of which are four-wire sensors.

[0016] Preferably, the interface includes a remote control interface, a power interface and several data interfaces; the data interface connects the optical fiber and the tunable narrowband light source and the photodetector module of the control board; the remote control interface connects the host computer and the data acquisition and control module of the control board, and the power interface connects the power supply and the filter of the power board.

[0017] It can be seen from the above technical solution that compared with the existing technology, the utility model discloses an airborne single-machine life monitoring sensor data acquisition device, which comprehensively collects deformation signals and temperature signals at various positions of the single machine by distributing optical fiber sensors on the single machine, and then filters, demodulates and transmits the signals through the host, thereby collecting single-machine monitoring signals in real time and reliably, which helps to timely and accurately predict the life of the single machine, improve aircraft flight safety, and reduce maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0019] Figure 1 The accompanying drawing is a schematic diagram of the overall structure of the host provided by the utility model;

[0020] Figure 2 The accompanying drawing is a schematic diagram of the appearance structure of the host provided by the utility model;

[0021] Figure 3 The accompanying drawing is a schematic diagram of the structure of the pretreatment plate provided by the utility model;

[0022] Figure 4 The accompanying drawing is a schematic diagram of the structure of the power supply board provided by the utility model;

[0023] Figure 5 The accompanying drawing is a schematic diagram of the control panel structure provided by the utility model;

[0024] Figure 6 The accompanying drawing is a schematic diagram of the circuit structure of the pre-processing board provided by the utility model.

[0025] In the accompanying drawings: 1-housing, 21-power board, 22-control board, 23-preprocessing board, 31-data interface, 32-remote control interface, 33-power interface. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described 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 making creative efforts are within the scope of protection of the present invention.

[0027] The embodiment of the utility model discloses an airborne single-machine life monitoring sensor data acquisition device, which includes a plurality of fiber optic sensors, a host and optical fibers; the fiber optic sensors are distributed and fixed on aircraft structural parts and connected to the host through optical fibers; the host includes a shell 1, a main control board and a plurality of interfaces; the main control board is arranged in the shell 1, and the interface is arranged on a side of the shell 1 and connected to the main control board; the optical fiber is connected to the interface; the main control board includes a preprocessing board 23, a power board 21 and a control board 22; the preprocessing board 23 is connected to the interface and the control board 22, and the power board 21 is connected to the preprocessing board 23 and the control board 22.

[0028] Furthermore, the pre-processing board includes a connected T-type filter and an RFI low-pass filter circuit; the T-type filter and the RFI low-pass filter circuit are both connected to the interface, and the T-type filter is connected to the power board.

[0029] Furthermore, the power board includes a filter, a DC isolator and a voltage conversion module; the input end of the filter is connected to the interface, the output end of the filter is connected to the input end of the DC isolator, and the output end of the DC isolator is connected to the T-type filter of the preprocessing board and the control board through the voltage conversion unit.

[0030] Furthermore, the control board includes a tunable narrowband light source, a wavelength calibration module, a photodetector module, a signal processing module, and a data acquisition and control module, all connected in sequence. The tunable narrowband light source includes an ASE light source, an optical attenuator, a tunable FP filter, and an optical splitter, all connected in sequence. The optical splitter is connected to an interface, and the tunable FP filter is connected to the wavelength calibration module. The photodetector module includes a photodetection circuit, a zeroing circuit, an amplification circuit, and a filtering circuit, all connected in sequence. The photodetection circuit is connected to an interface. The signal processing circuit includes a modulation and demodulation circuit. The data acquisition and control module includes a data acquisition card, an analog-to-digital converter, a controller, and a network port transmission module, all connected in sequence. The network port transmission module is connected to an interface. All of the above modules and components can utilize mature circuit structures and electronic components from existing technologies.

[0031] Furthermore, the RFI low-pass filter circuit includes a common-mode filter circuit and a differential-mode filter circuit.

[0032] Furthermore, the wavelength calibration module includes an FP etalon. The FP etalon serves as a reference grating for wavelength calibration. The FP etalon can output a series of peak values ​​with fixed wavelengths and similar powers. Therefore, the FP etalon is also called a comb filter. An FP etalon with a mark point can be selected, that is, there is a missing fixed wavelength value in the comb waveform of the FP etalon. The wavelength value missing at the mark point will be used as the calibration wavelength, that is, the reference wavelength value. The FP etalon outputs a series of fixed wavelength peaks that cover the entire wavelength range of the sensing grating. The wavelength value of each peak of the FP etalon can be calculated from the wavelength value of the mark point. Within a smaller output range, the wavelength and the corresponding scanning voltage are approximately linearly related, so that a corresponding relationship between the wavelength and the scanning voltage can be established.

[0033] Furthermore, the data acquisition card used is the NI6361 data acquisition card. The NI6361 data acquisition card has analog output and input ports with a resolution of 16 bits, and can simultaneously perform data acquisition and control of the tuned FP filter.

[0034] Furthermore, the optical fiber sensors include strain sensors and temperature sensors, all of which adopt four-wire sensors.

[0035] Furthermore, the controller uses FPGA, DSP or single-chip microcomputer. The FPGA can choose the Cyclone III series EP3C120F484 chip produced by INTEL, which has 432 M9K memory blocks and 3888KB of embedded storage space. The rich storage resources support the FPGA's real-time processing of large-capacity data to meet the system storage requirements. The FPGA can synchronously collect and process large amounts of data from the spectra of 16-channel sensors and the spectra of a wavelength calibration module. The FPGA drives the data acquisition card to collect data, converts the multi-channel spectral analog signals into digital signals through the analog-to-digital converter, and transmits them to the FPGA.

[0036] Furthermore, the interface includes a remote control interface 32, a power interface 33 and several data interfaces 31; the data interface 31 connects the optical fiber and the tunable narrowband light source and photodetector module of the control board 22; the remote control interface 32 connects the host computer and the microcontroller of the control board 22, and the power interface 33 connects the power supply and the filter of the power board.

[0037] Furthermore, the photodetector module can be a GT322D InGaAs detector. The photodetector module is used to convert the optical signal into an electrical signal and is located at the rear end of the sensing optical path and the FP etalon.

[0038] Furthermore, the housing 1 includes a bottom box and a cover plate, which are fixedly connected by screws. The cover plate is provided with screw holes for fixing the host on the aircraft.

[0039] Furthermore, the pre-processing board 23 is located in the bottom box on one side of the interface and can be connected to the control board via a patch panel.

[0040] Furthermore, the modulation and demodulation circuit can use many demodulation methods to detect small changes in the central wavelength of the fiber Bragg grating, including matched filtering, unbalanced Mach-Zehnder (MZ) interferometer, tunable fiber Bragg grating filter, tunable Fabry-Perot (FP) filter, etc.

[0041] Furthermore, the tunable FP filter includes two sets of reflectors, piezoelectric ceramics, and a drive circuit. The two sets of reflectors are arranged side by side, with the gap between them forming a tunable FP cavity. The piezoelectric ceramics are placed on the reflectors on the side of the incident light from the ASE light source, and the drive circuit is connected to the piezoelectric ceramics. Of the two high-reflection mirrors that constitute the tunable FP cavity, one is fixed, while the other is movable under the influence of an external force, and the piezoelectric ceramic is affixed to the back surface. The extension of the FP cavity length is proportional to the applied drive voltage. When a sawtooth scanning voltage is applied to the piezoelectric ceramic, the piezoelectric ceramic will expand and contract, thereby changing the cavity length of the FP cavity and changing the wavelength of the transmitted light of the FP cavity, thereby achieving the purpose of tunable transmitted light wavelength. The tunable narrowband light source composed of an ASE light source and a tunable FP filter is controlled by a tunable FP cavity control module. The tunable FP cavity control module generates a periodic sawtooth voltage, which is applied to the tunable FP filter. The cavity length of the tunable FP filter changes periodically with the sawtooth voltage. Different cavity lengths of the tunable FP filter correspond to different wavelength values. Therefore, among the broadband light emitted by the ASE light source, only the light with a wavelength matching the cavity length of the tunable FP filter can pass through the tunable FP filter, and at each moment, only one light with a certain wavelength value can pass through the tunable FP filter.

[0042] Furthermore, in the photodetector module, the photodetection circuit is used to convert the optical signal into an electrical signal; the zeroing circuit is used to improve the detection sensitivity and protect the device when detecting dynamic signals. Because the photodetection circuit has a large base value, when the change is too small, the relative change is too small and difficult to detect. If the amplification factor is too large, the amplifier will be saturated and the data acquisition card will be damaged. The amplification circuit is divided into pre-amplification and secondary amplification. Among them, the pre-amplification is to pre-amplify the output signal of the detector to obtain a better signal-to-noise ratio, perform impedance transformation, and reduce interference in signal transmission. The secondary amplification is mainly considered to be not too large. The amplitude of the signal after pre-amplification is still relatively small and cannot be well collected and processed by the data acquisition card. With the addition of secondary amplification, the signal amplitude can be adjusted more flexibly, which facilitates the flexible use of the system; the filtering circuit is used to filter out the noise in the useful signal to obtain a relatively clean signal. The weak analog signal will be interfered with during the amplification process, causing the amplitude or phase of the transmitted signal to be distorted. Therefore, the weak analog signal is filtered.

[0043] Furthermore, an optical splitter is used to evenly divide the tunable narrowband light into eight paths, enabling multi-channel demodulation. This splitter can evenly divide the optical path into multiple paths. Compared to an optical switch, it allows the device to demodulate multiple channels simultaneously without the channel switching time, thus increasing the demodulation rate.

[0044] Furthermore, an optical attenuator is placed between the ASE light source and the tunable FP filter to attenuate the light source's optical power to a power range acceptable to the tunable FP filter. Because the light source's power is 10dBm-13dBm, or 10 to 20mW, and the tunable FP filter's input power is 9mW, the light source's power exceeds the filter's maximum input power. The optical attenuator's attenuation coefficient is greater than 4.3dB.

[0045] On the other hand, in a specific embodiment, the preprocessing board includes an operational amplifier U, four T-type filters S1-S4, five resistors R1-R5 and three capacitors C1-C3; wherein, one end of the resistor R1 is directly connected to the +5V power supply provided by the power supply board, and the other end is respectively connected to the non-inverting input terminal of the operational amplifier and one end of the T-type filter S1, and the other end of the T-type filter S1 is connected to one end of the T-type filter S2 as the positive power supply terminal A; the output end of the operational amplifier U is connected to the inverting input terminal to form a voltage follower, and the inverting input terminal is connected to the ground terminal to ensure that the voltage of the non-inverting input terminal is always zero; the other end of the T-type filter S2 is connected to the differential voltage input terminal D through the resistor R4, and is also connected to AGND through the resistor R2; one end of the T-type filter S3 and the T-type filter S4 is connected as the negative power supply terminal B; the other end of the T-type filter S3 is connected to the differential voltage input terminal E through the resistor R5, and The differential voltage input terminals D and E are connected to AGND via capacitor C3. The differential voltage input terminal D is connected to AGND via capacitor C1, and the differential voltage input terminal E is connected to AGND via capacitor C2. The negative power supply terminal B is connected to AGND via a T-type filter S4. The ground terminals of all T-type filters are connected to the shield ground, using model GTL2012X-103T801. Resistors R4-R5 and capacitors C1-C3 form an RFI low-pass filter circuit to achieve low-pass filtering of the input signal and filter out differential-mode interference and common-mode interference carried in the input differential signal. The positive and negative power supply terminals A and B are connected to the power line of the four-wire sensor, and the differential voltage input terminals D and E are connected to the signal line of the four-wire sensor. The power output terminal of the power board is connected to resistor R1 to provide a +5V power supply, and the ground line is connected to the inverting input terminal of the operational amplifier U. The pre-processing board can effectively eliminate electromagnetic and RFI radiation interference, greatly improving the reliability of the acquisition. In addition, the voltage is directly measured from the positive pole A and the negative pole B of the power supply, eliminating the error caused by the lead resistance and improving the accuracy of the resistance value.

[0046] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0047] The above description of the disclosed embodiments will enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An airborne single-machine life monitoring sensor data acquisition device, characterized in that: The system comprises a plurality of fiber optic sensors, a host and optical fibers; the fiber optic sensors are distributed and fixed on aircraft structural parts and connected to the host through the optical fibers; the host comprises a housing, a main control board and a plurality of interfaces; the main control board is arranged in the housing, the interfaces are arranged on a side of the housing and connected to the main control board; the optical fibers are connected to the interfaces; the main control board comprises a preprocessing board, a power supply board and a control board; the preprocessing board is connected to the interfaces and the control board, and the power supply board is connected to the preprocessing board and the control board.

2. The airborne single-machine life monitoring sensor data acquisition device according to claim 1, characterized in that: The pre-processing board includes a connected T-type filter and an RFI low-pass filter circuit; the T-type filter and the RFI low-pass filter circuit are both connected to the interface, and the T-type filter is connected to the power supply board.

3. The airborne single-machine life monitoring sensor data acquisition device according to claim 1, characterized in that: The power supply board includes a filter, a DC isolator and a voltage conversion module; the input end of the filter is connected to the interface, the output end of the filter is connected to the input end of the DC isolator, and the output end of the DC isolator is connected to the preprocessing board and the control board through the voltage conversion unit.

4. The airborne single-machine life monitoring sensor data acquisition device according to claim 1, characterized in that: The control panel includes a tunable narrowband light source, a wavelength calibration module, a photodetector module, a signal processing module, and a data acquisition and control module connected in sequence; wherein the tunable narrowband light source includes an ASE light source, an optical attenuator, a tunable FP filter, and an optical splitter connected in sequence, the optical splitter is connected to the interface, and the tunable FP filter is connected to the wavelength calibration module; the photodetector module includes a photoelectric detection circuit, a zero adjustment circuit, an amplification circuit, and a filtering circuit connected in sequence, and the photoelectric detection circuit is connected to the interface; the signal processing circuit includes a modulation and demodulation circuit; the data acquisition and control module includes a data acquisition card, an analog-to-digital converter, a controller, and a network port transmission module connected in sequence, and the network port transmission module is connected to the interface.

5. The airborne single-machine life monitoring sensor data acquisition device according to claim 2, characterized in that: The RFI low-pass filter circuit includes a common-mode filter circuit and a differential-mode filter circuit.

6. The airborne single-machine life monitoring sensor data acquisition device according to claim 4, characterized in that: The wavelength calibration module includes a FP etalon.

7. The airborne single-machine life monitoring sensor data acquisition device according to claim 4, characterized in that: The data acquisition card used is N16361 data acquisition card.

8. The airborne single-machine life monitoring sensor data acquisition device according to claim 1, characterized in that: The optical fiber sensor includes a strain sensor and a temperature sensor.

9. The airborne single-machine life monitoring sensor data acquisition device according to claim 1, characterized in that: The interface includes a remote control interface, a power interface and several data interfaces; the data interface connects the optical fiber and the control board; the remote control interface connects the host computer and the control board, and the power interface connects the power supply and the power board.

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