A fast demodulation method and device for FBG array sensor

Abstract

This invention provides a fast demodulation method and apparatus for FBG array sensors, enabling rapid real-time demodulation of signals from multiple FBG sensors. The fast demodulation method modulates a laser source into pulsed light using a pulse driving circuit, and then shapes the pulsed light into pulsed laser light using a spectral line triangular shaping filter. Employing time-division multiplexing, the shaped pulsed laser light is input to the FBG sensor array via a coupler. After acquiring the reflected signal from the sensor array, it is again input to a photodetector and amplification circuit via a coupler to obtain the reflected signal from the sensor array. A comparator signal array composed of multiple voltage comparators is used to compare and determine the acquired signals, and the corresponding grating wavelength value is determined based on the matched voltage value. An AD acquisition and signal processing circuit controls and synchronizes the pulse driving circuit, achieving accurate and stable demodulation, facilitating rapid real-time demodulation of signals from multiple FBG sensors.

Description

Technical Field

[0001] This invention relates to the field of Internet of Things (IoT) technology, specifically to a fast demodulation method and apparatus for an FBG array sensor. Background Technology

[0002] FBG (Fiber Bragg Grating) sensors are sensors based on the Bragg grating principle in optical fibers, widely used in the detection of physical quantities such as temperature, strain, displacement, and vibration. Due to their superior performance, FBG sensors are widely used in power grid monitoring, structural health monitoring, and other fields, especially in harsh environments such as high temperature and humidity, corrosive environments, and environments requiring electromagnetic interference, where FBG sensors demonstrate unparalleled advantages over other sensors. Furthermore, FBG sensors can be used to build distributed sensor networks, enabling multi-point monitoring of large facilities, and have broad application prospects.

[0003] However, existing FBG sensor demodulation methods have some limitations. First, some methods are costly, restricting their application. Second, traditional demodulation methods have limitations in demodulation speed and accuracy, failing to meet the growing demands of power grid monitoring and structural health monitoring. Especially when rapid demodulation of multiple FBG sensor signals is required, traditional methods may suffer from slow demodulation speeds, affecting real-time monitoring performance. Furthermore, increasing the number of sensors may be limited by laser bandwidth, further restricting the scalability of demodulation.

[0004] Therefore, it is necessary to propose a novel demodulation method for FBG array sensors to meet the requirements of fast demodulation speed, low cost, and high reliability. Summary of the Invention

[0005] In view of this, the present invention proposes a fast demodulation method and apparatus for FBG array sensors. By fully utilizing spectral line shaping and data processing with multiple voltage comparators, fast real-time demodulation of signals from multiple FBG sensors is achieved, thereby breaking through the limitations of traditional demodulation methods and meeting the needs of different fields for efficient demodulation.

[0006] To achieve the above objectives, in a first aspect, the present invention provides a fast demodulation method for FBG array sensors, used to realize fast real-time demodulation of signals from multiple FBG sensors, the method comprising the following steps: The laser source is modulated into pulsed light by a pulse driving circuit, and the pulsed light is shaped into pulsed laser by a laser spectrum shaping filter. Using the time-division multiplexing principle, the shaped pulsed laser is input into the FBG sensor array through a coupler. The signal reflected back from the FBG sensor array is collected and then input into the photodetector and amplification circuit through the coupler to obtain the reflected signal of the FBG sensor array. The collected reflected signals are compared and detected using a comparator signal array, with the voltage value of each comparator corresponding to the wavelength value of the calibrated grating. When the voltage value of the reflected signal matches the voltage value of the comparator, the corresponding grating wavelength value is quickly determined; the AD acquisition and signal processing circuit is used to control and synchronize the pulse drive circuit.

[0007] As a further embodiment of the present invention, the laser source is selected as a laser source with a 3dB bandwidth greater than 3nm, and the filter is a spectral line triangulation filter used to shape the pulsed light into a pulsed laser.

[0008] As a further embodiment of the present invention, the coupler is a 3dB coupler, and a delay fiber is connected before each FBG sensor to ensure accurate signal timing.

[0009] As a further aspect of the present invention, the spectral line triangular shaping filter is a quasi-linear filter used to shape the spectrum during demodulation, thereby improving demodulation accuracy and stability.

[0010] As a further aspect of the present invention, the delay fiber is used to ensure that the reflected signal of each FBG sensor is demodulated within the correct time window, thereby achieving rapid demodulation of multiple sensors.

[0011] As a further aspect of the present invention, the initial wavelength of the FBG sensor array is the same as the peak wavelength of the laser light source. When affected by temperature or strain, the wavelength of the FBG sensor array drifts.

[0012] As a further aspect of the present invention, the comparator signal array consists of multiple voltage comparators, each of which has a calibrated voltage value for accurate comparison and determination of signals of different wavelengths; the comparator signal array can distinguish different voltage values, thereby achieving rapid demodulation of different wavelengths.

[0013] As a further aspect of the present invention, the pulse driving circuit has a stable pulse period and pulse width control. The pulse period of the pulse driving circuit is 2MHz and the pulse width control is 10ns to ensure stable pulse light source output.

[0014] As a further aspect of the present invention, the demodulation method, by processing multiple voltage comparators in parallel, can simultaneously demodulate multiple FBG sensor signals, thereby achieving a highly efficient demodulation process.

[0015] As a further aspect of the present invention, the photodetector and amplification circuit are used to acquire and amplify the reflected signal to ensure the stability and clarity of the demodulated signal.

[0016] As a further aspect of the present invention, the AD acquisition and signal processing circuit is used to control and synchronize the pulse drive circuit to ensure the accuracy and synchronization of the demodulation process.

[0017] As a further aspect of the present invention, the laser source has a 3dB bandwidth greater than 3nm, ensuring sufficient spectral width to meet the demodulation requirements of multiple sensors.

[0018] As a further aspect of the present invention, the demodulation method of the FBG array sensor, under the collaborative operation of multiple sensors, can realize real-time monitoring and rapid demodulation of different parameters (such as temperature, strain, etc.). The demodulation method of the FBG array sensor can also be applied to multiple fields such as power grid detection and structural health monitoring, realizing rapid real-time demodulation of multiple sensor signals, and has broad application prospects.

[0019] Secondly, the present invention provides a fast demodulation device for an FBG array sensor, used to achieve fast real-time demodulation of signals from multiple FBG sensors, including: A pulse drive circuit is used to modulate the laser source into pulsed light; A spectral line triangulation filter is used to shape pulsed light into pulsed laser light. A time-division multiplexing system is used to input shaped pulsed laser light into an FBG sensor array via a coupler; Photodetectors and amplifier circuits are used to acquire and amplify signals reflected from the sensor array; A comparator signal array consisting of multiple voltage comparators is used to compare and determine signals; The AD acquisition and signal processing circuit is used to control and synchronize the pulse drive circuit.

[0020] As a further aspect of the present invention, it also includes: a time-delay fiber, used to ensure that the reflected signal of each FBG sensor is demodulated within the correct time window; As a further aspect of the present invention, the pulse driving circuit has stable pulse period and pulse width control to ensure the stability and controllability of the pulse light source output.

[0021] The fast demodulation device for FBG array sensors of the present invention can be widely used in fields such as power grid detection and structural health monitoring, providing an efficient, reliable, fast, and real-time demodulation solution for multiple sensor signals.

[0022] In another aspect, the present invention provides a computer device including a memory and a processor, the memory storing a computer program which, when executed by the processor, performs any of the above-described fast demodulation methods for the FBG array sensor according to the present invention.

[0023] In another aspect, the present invention provides a computer-readable storage medium storing computer program instructions that, when executed, implement the fast demodulation method of the FBG array sensor according to any of the above-described methods.

[0024] Compared with existing technologies, the fast demodulation method and apparatus for FBG array sensors proposed in this invention have the following advantages: 1. Fast real-time demodulation capability: By adopting the time-division multiplexing principle and the structure of multiple voltage comparators, this invention can quickly demodulate multiple FBG sensor signals in real time, achieve efficient signal processing, greatly improve demodulation speed, and meet real-time monitoring requirements.

[0025] 2. Overcoming the limitation on the number of sensors: Traditional FBG demodulation methods are limited by the laser bandwidth, which restricts the number of sensors that can be demodulated simultaneously. This invention uses spectral line triangulation and multiple voltage comparators to overcome the bandwidth limitation on the number of sensors, enabling simultaneous demodulation of multiple sensors.

[0026] 3. Improved demodulation accuracy and stability: A spectral line triangulation filter is used to shape the pulsed laser, improving demodulation accuracy and stability. The use of a voltage comparator accurately determines the voltage value corresponding to different wavelengths, further enhancing demodulation precision.

[0027] 4. High-efficiency multi-sensor monitoring: By processing multiple voltage comparators in parallel, this invention can demodulate multiple sensor signals simultaneously, achieving a high-efficiency demodulation process and improving the efficiency of multi-sensor monitoring.

[0028] In summary, the fast demodulation method and apparatus for FBG array sensors of the present invention offer low cost, speed, accuracy, and stable demodulation performance. It can handle complex environments and is suitable for various application scenarios, such as power grid monitoring and structural health monitoring. It can operate stably in complex environments including high temperature and humidity, corrosive environments, and environments requiring electromagnetic interference, demonstrating broad applicability. Furthermore, compared to other demodulation methods, the equipment used is relatively simple, requiring no high equipment investment, thus reducing costs. Simultaneously, through reasonable signal processing methods, the reliability and accuracy of demodulation are improved, enabling it to play a significant role in monitoring needs across multiple fields.

[0029] These or other aspects of this application will become more apparent from the following description of embodiments. It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only, and are not intended to limit the application. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort.

[0031] In the diagram: Figure 1 This is a flowchart of a fast demodulation method for an FBG array sensor according to an embodiment of the present invention; Figure 2 This is a system block diagram of a fast demodulation method and apparatus for an FBG array sensor according to an embodiment of the present invention; Figure 3 This is a basic schematic diagram of laser spectral shaping in a fast demodulation method for an FBG array sensor according to an embodiment of the present invention.

[0032] Figure 4 This is a diagram of the pulse signal of the FBG sensor detected at each return time in a fast demodulation method for an FBG array sensor according to an embodiment of the present invention.

[0033] Figure 5 This is a timing diagram of the actual signal acquired in a fast demodulation method and device for an FBG array sensor according to an embodiment of the present invention. Detailed Implementation

[0034] The present application will now be further described in conjunction with the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0035] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to specific examples and the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0036] It should be noted that all uses of the terms "first" and "second" in the embodiments of the present invention are for the purpose of distinguishing two different entities or different parameters with the same name. Therefore, "first" and "second" are merely for convenience of expression and should not be construed as limiting the embodiments of the present invention. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion, such as other steps or units inherent in a process, method, apparatus, product, or device that includes a series of steps or units.

[0037] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0038] The flowchart shown in the attached diagram is for illustrative purposes only and does not necessarily include all content and operations / steps, nor does it necessarily have to be performed in the order described. For example, some operations / steps can be broken down, combined, or partially merged, so the actual execution order may change depending on the actual situation.

[0039] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0040] Currently, demodulation methods based on various types of FBG array sensors are generally quite expensive. Therefore, there is a need to find a cost-effective and reliable FBG signal demodulation method to meet the growing demands for power grid monitoring and structural health monitoring.

[0041] This invention proposes a novel demodulation method for FBG array sensors. Based on time-division multiplexing and combined with spectral line triangulation, it utilizes data processing methods with multiple voltage comparators to quickly determine the wavelength, thereby achieving rapid real-time demodulation of multiple FBGs.

[0042] This invention proposes a fast demodulation method and apparatus for FBG array sensors. By fully utilizing spectral line shaping and data processing with multiple voltage comparators, it achieves fast real-time demodulation of signals from multiple FBG sensors, thereby overcoming the limitations of traditional demodulation methods and meeting the needs of various fields for efficient demodulation.

[0043] See Figure 1 and Figure 2 As shown, an embodiment of the present invention provides a fast demodulation method for an FBG array sensor, used to achieve fast real-time demodulation of signals from multiple FBG sensors. The method includes the following steps: Step S10: The laser source is modulated into pulsed light by a pulse driving circuit, and the pulsed light is shaped into pulsed laser by a laser spectrum shaping filter.

[0044] Step S20: Using the time-division multiplexing principle, the shaped pulsed laser is input into the FBG sensor array through a coupler. The signal reflected back from the FBG sensor array is collected and input into the photodetector and amplification circuit through the coupler again to obtain the reflected signal of the FBG sensor array.

[0045] Step S30: Use a comparator signal array to compare and detect the acquired reflected signals. The voltage value of each comparator corresponds to the wavelength value of the calibrated grating.

[0046] Step S40: When the voltage value of the reflected signal matches the voltage value of the comparator, quickly determine the corresponding grating wavelength value; use the AD acquisition and signal processing circuit to control and synchronize the pulse drive circuit.

[0047] In the fast demodulation method of the FBG array sensor in this embodiment of the invention, a laser source with a 3dB bandwidth greater than 3nm is selected and modulated into pulsed light by a pulse driving circuit. The pulsed light then passes through a filter for laser spectral shaping; this filter is quasi-linear. The filter can be an FBG sensor with a 3dB bandwidth of 3nm, a Fabry-Perot interferometer, a fiber Sagnac interferometer with a 3nm bandwidth, or a Mach-Zehnder interferometer. This allows for spectral shaping of the laser source. The shaped pulsed laser light passes through a 3dB coupler into the FBG sensor array. Each FBG is connected to a delay fiber. The signal reflected back from the FBG array passes through another 3dB coupler into a photodetector and amplification circuit for acquisition and amplification. Then, it enters a comparator signal array for signal comparison and detection. The voltage value corresponding to each comparator corresponds to the wavelength value of a calibrated grating. When the returned voltage signal corresponds to the voltage value of the comparator, the wavelength value of the returned grating can be quickly determined. An AD acquisition and signal processing circuit is used to control and synchronize the pulse driving circuit.

[0048] In this embodiment, the spectral line triangular shaping filter is a quasi-linear filter used to shape the spectrum during demodulation, thereby improving demodulation accuracy and stability; the delay fiber is used to ensure that the reflected signal of each FBG sensor is demodulated within the correct time window, enabling rapid demodulation of multiple sensors.

[0049] In this embodiment, the initial wavelength of the FBG sensor array is the same as the peak wavelength of the laser light source. When affected by temperature or strain, the wavelength of the FBG sensor array drifts.

[0050] In this embodiment, the comparator signal array consists of multiple voltage comparators, each of which has a calibrated voltage value for accurate comparison and determination of signals of different wavelengths. The comparator signal array can distinguish between different voltage values, thereby enabling rapid demodulation of different wavelengths.

[0051] The pulse driving circuit features stable pulse period and pulse width control. The pulse period is 2MHz, and the pulse width is 10ns to ensure stable pulse light source output. The demodulation method of this invention, by processing multiple voltage comparators in parallel, can simultaneously demodulate signals from multiple FBG sensor sensors, achieving a highly efficient demodulation process. The photodetector and amplification circuit are used to acquire and amplify the reflected signals. The photodetector detects the voltage signals reflected back from the FBG at different times, and the amplifier amplifies the voltage signals to ensure the stability and clarity of the demodulated signal. The AD acquisition and signal processing circuit is used to control and synchronize the pulse drive circuit, determine the voltage value input to the comparator, and simultaneously synchronize the drive pulses, determining the timing of the pulse returns to ensure the accuracy and synchronization of the demodulation process. The laser source has a 3dB bandwidth greater than 3nm, ensuring sufficient spectral width to meet the demodulation requirements of multiple sensors.

[0052] In this embodiment, when the comparator signal array is used to compare and detect the collected reflected signals, the comparator signal array is entered. It is determined whether the comparator 1 / 2 / 3... etc. need to distinguish the signal reflected back by each FBG: the voltage signal reflected back by each FBG needs to be determined and distinguished at 10mV intervals. Each comparator corresponds to / is responsible for the voltage signal value reflected back by one FBG, which also corresponds to one FBG wavelength.

[0053] The demodulation method of the FBG array sensor of the present invention can realize real-time monitoring and rapid demodulation of different parameters (such as temperature, strain, etc.) under the collaborative work of multiple sensors. The FBG array sensor demodulation method can also be applied to multiple fields such as power grid detection and structural health monitoring, realizing rapid real-time demodulation of multiple sensor signals, and has broad application prospects.

[0054] See Figure 3 As shown, Figure 3 This is a basic principle diagram of laser spectrum shaping in the demodulation method of the FBG array sensor of the present invention, wherein the laser spectrum is combined with the quasi-linear fiber filter spectrum to finally shape the output light source spectrum.

[0055] See Figure 4 As shown, Figure 4This is a pulse signal diagram of the FBG sensor detected at each return time in the demodulation method of the FBG array sensor of the present invention, wherein, Figure 4 In this embodiment, the light source spectrum is actually a linear filter that linearly filters the wavelength values ​​of the FBG, but the signal of each FBG is separated in time. In one embodiment of the present invention, a 1551.928nm laser is selected as the light source. The demodulation scheme of the present invention is tested by a grating array with 8 peak wavelengths of 1551.92nm, a reflectivity of 1.5%, a 3dB bandwidth of 0.2nm, and a spacing of 2 meters. The pulse period of the pulse driving circuit is 2MHz and the pulse width is controlled at 10ns. Figure 5 This is a timing diagram of the signal actually acquired by the demodulation system of this invention. The wavelength of the FBG can be determined by the voltage value of each pulse through a comparator. The wavelength resolution of the demodulator is determined by the resolution set in the comparator voltage value. The comparator can distinguish a voltage signal difference of 10mV. For every 10pm wavelength drift, the voltage value changes by 10mV. Within a dynamic demodulation range of 1nm, 100 voltage comparators can quickly achieve a wavelength differentiation demodulation accuracy of 10pm. Increasing the number of comparators can further improve the wavelength demodulation range of the demodulator.

[0056] In summary, the fast demodulation method for an FBG array sensor of the present invention modulates a laser source into pulsed light through a pulse driving circuit, and then shapes it into pulsed laser light through a spectral line triangular shaping filter. Using the time-division multiplexing principle, the shaped pulsed laser light is input to the FBG sensor array. After acquiring the reflected signal from the sensor array, it is input again through a coupler to a photodetector and amplification circuit to obtain the reflected signal from the sensor array. A comparator signal array composed of multiple voltage comparators is used to compare and determine the acquired signal, and the corresponding grating wavelength value is determined based on the matched voltage value. An AD acquisition and signal processing circuit is used to control and synchronize the pulse driving circuit to ensure the accuracy and synchronization of the demodulation process. The method and apparatus of the present invention have significant advantages in fast demodulation, overcoming sensor quantity limitations, improving demodulation accuracy, adapting to complex environments, and enabling multi-sensor collaborative operation. It is applicable to multiple application fields and brings innovation and breakthroughs to the field of sensor monitoring.

[0057] It should be noted that the above figures are merely illustrative of the processes included in the method according to exemplary embodiments of the present invention, and are not intended to be limiting. It is readily understood that the processes shown in the above figures do not indicate or limit the temporal order of these processes. Furthermore, it is readily understood that these processes may, for example, be executed synchronously or asynchronously in multiple modules.

[0058] It should be understood that although the above description follows a certain order, these steps are not necessarily executed in that order. Unless otherwise expressly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, some steps in this embodiment may include multiple steps or multiple stages, which are not necessarily completed at the same time, but may be executed at different times. The execution order of these steps or stages is not necessarily sequential, but may be performed alternately or in turn with other steps or at least a portion of the steps or stages in other steps.

[0059] A second aspect of the present invention is described in [reference 1]. Figure 2 As shown, the present invention also provides a fast demodulation device for an FBG array sensor, comprising: A pulse drive circuit is used to modulate the laser source into pulsed light; A spectral line triangulation filter is used to shape pulsed light into pulsed laser light. A time-division multiplexing system is used to input shaped pulsed laser light into an FBG sensor array via a coupler; Photodetectors and amplifier circuits are used to acquire and amplify signals reflected from the sensor array; A comparator signal array consisting of multiple voltage comparators is used to compare and determine signals; The AD acquisition and signal processing circuit is used to control and synchronize the pulse drive circuit.

[0060] As a further aspect of the present invention, it also includes: a time-delay fiber, used to ensure that the reflected signal of each FBG sensor is demodulated within the correct time window; In this embodiment, the pulse driving circuit has stable pulse period and pulse width control to ensure the stability and controllability of the pulse light source output.

[0061] The fast demodulation device for FBG array sensors of the present invention can be widely used in fields such as power grid detection and structural health monitoring, providing an efficient, reliable, fast, and real-time demodulation solution for multiple sensor signals.

[0062] For example, in a power grid monitoring application, the fast demodulation device of the present invention is used to monitor multiple FBG sensors on a power transmission line. By using this device, signals from multiple sensors can be demodulated simultaneously, enabling rapid real-time monitoring of the power grid status. The device's stability and efficiency allow for accurate acquisition of sensor data even in complex power environments, providing crucial operation and maintenance support. Furthermore, this device can also be applied to other fields, such as structural health monitoring, enabling multi-sensor collaborative operation and providing robust data support for the safety of engineering projects and facilities.

[0063] In summary, the fast demodulation device for FBG array sensors of the present invention includes key components such as a pulse driving circuit, a spectral line triangulation filter, a time-division multiplexing system, a photodetector and amplification circuit, a comparator signal array composed of multiple voltage comparators, and AD acquisition and signal processing circuits. This fast demodulation device for FBG array sensors can shape pulsed light signals into pulsed lasers through a spectral line triangulation filter, and then simultaneously demodulate multiple FBG sensors through a time-division multiplexing system. The comparator signal array compares the acquired signals with pre-calibrated voltage values ​​to quickly determine the wavelength value of the grating. This device has advantages such as fast demodulation speed, high demodulation accuracy, and adaptability to complex environments, and can be widely used in fields such as power grid detection and structural health monitoring, bringing an efficient and reliable fast demodulation solution to the field of sensor monitoring.

[0064] A third aspect of the present invention also provides a computer device, including a memory and a processor, wherein the memory stores a computer program that, when executed by the processor, implements the method of any of the above embodiments.

[0065] The computer device includes a processor and a memory, and may also include input and output devices. The processor, memory, input devices, and output devices can be connected via a bus or other means. The input devices can receive input digital or character information and generate signal inputs related to the fast demodulation migration of the FBG array sensor. The output devices may include display devices such as a screen.

[0066] Memory, as a non-volatile computer-readable storage medium, can be used to store non-volatile software programs, non-volatile computer-executable programs, and modules, such as the program instructions / modules corresponding to the fast demodulation method for the FBG array sensor in the embodiments of this application. Memory may include a program storage area and a data storage area, wherein the program storage area may store the application program required for operating the device and at least one function; the data storage area may store data created by using the fast demodulation method for the FBG array sensor, etc. Furthermore, memory may include high-speed random access memory and may also include non-volatile memory, such as at least one disk storage device, flash memory device, or other non-volatile solid-state storage device. In some embodiments, memory may optionally include memory remotely located relative to the processor, and these remote memories can be connected to the local module via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0067] In some embodiments, the processor may be a central processing unit (CPU), a controller, a microcontroller, a microprocessor, or other data processing chip. This processor is typically used to control the overall operation of a computer device. In this embodiment, the processor is used to run program code stored in memory or process data. In this embodiment, the processors of multiple computer devices execute various server functions and data processing by running non-volatile software programs, instructions, and modules stored in memory, thereby implementing the steps of the fast demodulation method for the FBG array sensor described in the above method embodiment.

[0068] It should be understood that, where there is no conflict, all the embodiments, features and advantages described above for the fast demodulation method of the FBG array sensor according to the present invention are equally applicable to the fast demodulation and storage medium of the FBG array sensor according to the present invention.

[0069] Those skilled in the art will also understand that the various exemplary logic blocks, modules, circuits, and algorithm steps described in conjunction with the disclosure herein can be implemented as electronic hardware, computer software, or a combination of both. To clearly illustrate this interchangeability between hardware and software, the functionality of various illustrative components, blocks, modules, circuits, and steps has been generally described. Whether this functionality is implemented as software or as hardware depends on the specific application and the design constraints imposed on the overall device. Those skilled in the art can implement the functionality in various ways for each specific application, but such implementation decisions should not be construed as departing from the scope of the embodiments disclosed herein.

[0070] Finally, it should be noted that the computer-readable storage medium (e.g., memory) described herein can be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. By way of example, and not limitation, non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory may include random access memory (RAM), which can act as external cache memory. By way of example, and not limitation, RAM can be obtained in various forms, such as synchronous RAM (DRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), and direct Rambus RAM (DRRAM). The storage devices disclosed herein are intended to include, but are not limited to, these and other suitable types of memory.

[0071] The various exemplary logic blocks, modules, and circuits described herein can be implemented or performed using the following components designed to perform the functions herein: general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic, discrete hardware components, or any combination of these components. A general-purpose processor may be a microprocessor, but alternatively, the processor may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors combined with a DSP, and / or any other such configuration.

[0072] The above are exemplary embodiments disclosed in this invention. However, it should be noted that various changes and modifications can be made without departing from the scope of the embodiments of this invention as defined by the claims. The functions, steps, and / or actions of the methods according to the disclosed embodiments described herein do not need to be performed in any particular order. Furthermore, although the elements disclosed in the embodiments of this invention may be described or claimed individually, they may be understood as multiple unless explicitly limited to a singular number.

[0073] It should be understood that, as used herein, the singular form "a" is intended to include the plural form as well, unless the context clearly supports an exception. It should also be understood that, as used herein, "and / or" refers to any and all possible combinations of one or more of the associatedly listed items. The embodiment numbers disclosed above are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0074] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples. Within the framework of the invention, technical features of the above embodiments or different embodiments can be combined, and many other variations of different aspects of the invention exist, which are not provided in the details for the sake of brevity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the protection scope of the invention.

Claims

1. A fast demodulation method for an FBG array sensor, characterized in that, To achieve fast real-time demodulation of signals from multiple FBG sensors, the following steps are included: The laser source is modulated into pulsed light by a pulse driving circuit, and the pulsed light is shaped into pulsed laser by a laser spectrum shaping filter. Using the time-division multiplexing principle, the shaped pulsed laser is input into the FBG sensor array through a coupler. The signal reflected back from the FBG sensor array is collected and then input into the photodetector and amplification circuit through the coupler to obtain the reflected signal of the FBG sensor array. The collected reflected signals are compared and detected using a comparator signal array, with the voltage value of each comparator corresponding to the wavelength value of the calibrated grating. When the voltage value of the reflected signal matches the voltage value of the comparator, the corresponding grating wavelength value is quickly determined; the AD acquisition and signal processing circuit is used to control and synchronize the pulse drive circuit. The laser source is selected as a laser source with a 3dB bandwidth greater than 3nm, the filter is a spectral line triangulation filter, the coupler is a 3dB coupler, and a delay fiber is connected in front of each FBG sensor. The comparator signal array consists of multiple voltage comparators, each with a calibrated voltage value, used to accurately compare and determine signals of different wavelengths. The comparator signal array is used to distinguish between different voltage values. A comparator signal array composed of multiple voltage comparators is used to compare and determine the acquired signals. The corresponding grating wavelength value is determined based on the matched voltage value. It is necessary to determine the voltage signal reflected back by each FBG. The comparator values ​​are distinguished in 10mV intervals, and the wavelength value reflected back by each FBG corresponds to the voltage value matched by the comparator.

2. The fast demodulation method for the FBG array sensor according to claim 1, characterized in that, The spectral line triangular shaping filter is a quasi-linear filter used to shape the spectrum during demodulation; the delay fiber is used to ensure that the reflected signal of each FBG sensor is demodulated within the correct time window.

3. The fast demodulation method for the FBG array sensor according to claim 2, characterized in that, The initial wavelength of the FBG sensor array is the same as the peak wavelength of the laser source. When affected by temperature or strain, the wavelength of the FBG sensor array drifts.

4. The fast demodulation method for the FBG array sensor according to claim 1, characterized in that, The pulse period of the pulse driving circuit is 2MHz, and the pulse width is controlled to be 10ns.

5. The fast demodulation method for the FBG array sensor according to claim 4, characterized in that, The photodetector and amplification circuit are used to acquire and amplify the reflected signal; the AD acquisition and signal processing circuit is used to control and synchronize the pulse drive circuit.

6. A fast demodulation device for an FBG array sensor, characterized in that, For performing the fast demodulation method of the FBG array sensor according to any one of claims 1-5, the fast demodulation device of the FBG array sensor comprises: A pulse drive circuit is used to modulate the laser source into pulsed light; A spectral line triangulation filter is used to shape pulsed light into pulsed laser light. A time-division multiplexing system is used to input shaped pulsed laser light into an FBG sensor array via a coupler; Photodetectors and amplifier circuits are used to acquire and amplify signals reflected from the sensor array; A comparator signal array consisting of multiple voltage comparators is used to compare and determine signals; The AD acquisition and signal processing circuit is used to control and synchronize the pulse drive circuit.

7. The fast demodulation device for the FBG array sensor according to claim 6, characterized in that, Also includes: Delayed fiber is used to ensure that the reflected signal from each FBG sensor is demodulated within the correct time window.

8. The fast demodulation device for the FBG array sensor according to claim 6, characterized in that, The pulse driving circuit described above has a stable pulse period and pulse width control. The pulse period of the pulse driving circuit is 2MHz and the pulse width control is 10ns.

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