Method for analyzing optical sensor signals having multi-wavelength optical signals and optical sensor system using same

Abstract

An optical sensor system and an optical sensor signal analysis method are provided. The optical sensor system comprises: a light source unit for emitting light in one sensing mode selected from a plurality of sensing modes; a multi-signal optical sensor unit for measuring a change amount of the light received from the light source unit to generate a multi-wavelength optical signal; a wavelength branching unit for dividing the multi-wavelength optical signal into a plurality of sub-wavelength optical signals on the basis of a preset wavelength range; and a signal analysis unit for analyzing the plurality of sub-wavelength optical signals to output an analysis result for the light.

Description

Method for analyzing optical sensor signals having multiple wavelength optical signals and an optical sensor system using the same

[0001] The technical field to which the present invention belongs relates to a technology for analyzing optical signals generated from an optical sensor, and more specifically, to an optical sensor signal analysis method and an optical sensor system using the same, which enables more accurate analysis by using multiple signals generated from an optical sensor and can calculate more accurate physical quantity data from the optical signals generated from the optical sensor.

[0002] The content described in this section merely provides background information regarding the present embodiment and does not constitute prior art.

[0003] Unlike conventional electric sensors, optical sensors, including fiber optic sensors, utilize light as a measurement method, enabling safe measurement without the risk of fire caused by electrical sparks or leakage currents in the sensor unit. For example, unlike electric sensors, fiber optic sensors are not affected by electromagnetic waves in the sensor unit, making them suitable for application in high-voltage power systems. Furthermore, since fiber optic sensors utilize optical fibers for measurement, they facilitate multi-measurement and remote measurement. Additionally, the sensor unit of a fiber optic sensor has the advantage of being miniaturizable. Moreover, fiber optic sensors are generally characterized by being composed entirely or partially of glass optical fibers with strong chemical resistance.

[0004] Conventional optical sensor signal analysis techniques utilize only the single-wavelength signals generated by the sensors, leading to the problem of significant noise inclusion. Consequently, physical quantities derived from single-wavelength signals suffer from limitations in resolution and accuracy. Addressing this requires using high-power laser sources or extending measurement times, which increases system costs and hinders high-speed measurement.

[0005] FIG. 1 is a diagram illustrating a signal analysis technique using a conventional single-wavelength optical signal, and FIG. 2 is a diagram illustrating the optical power and wavelength processed by a signal analysis technique using a conventional single-wavelength optical signal.

[0006] Referring to FIGS. 1 and 2, conventional signal analysis techniques using single-wavelength optical signals generate a lot of noise because they use single-wavelength optical signals collected at a single wavelength. Due to the generation of a lot of noise, the resolution of the generated data is reduced, making it difficult to calculate accurate physical quantities.

[0007] Conventional signal analysis techniques using single-wavelength optical signals utilize additional optical components, such as optical filters, to generate single-wavelength optical signals. Since the light source intensity must be increased to reduce noise generation, additional expensive optical amplifiers are used; furthermore, when optical output is increased using optical amplifiers, optical isolators must be used to protect the light source from high-output light reflected from the output section. In other words, there is a problem of increased system costs.

[0008] Regarding optical sensor signal analysis technology, Korean Registered Patent No. 10-2335752 describes a high-resolution optical wavelength power meter, a reflected optical wavelength scanning device using the same, and a reflected optical wavelength scanning system. Korean Registered Patent No. 10-1209627 describes an optical fiber sensor system based on a spectrometer. Korean Registered Patent No. 10-1703960 describes a frequency-variable distributed optical fiber sensor system. Korean Registered Patents No. 10-2335752, No. 10-1209627, and No. 10-1703960 merely describe optical sensor signal analysis and do not consider a configuration for analyzing multi-wavelength optical signals in multiple sensing modes.

[0009] [Prior Art Literature]

[0010] [Patent Literature]

[0011] (Patent Document 1) Korean Registered Patent No. 10-2335752 (December 6, 2021)

[0012] (Patent Document 2) Korean Registered Patent No. 10-1209627 (December 7, 2012)

[0013] (Patent Document 3) Korean Registered Patent No. 10-1703960 (February 22, 2017)

[0014] The embodiments of the present invention have a primary objective of improving noise characteristics, enhancing resolution, and reducing system costs by measuring a change in light received from a light source unit in a sensing mode selected from a plurality of sensing modes to generate a multi-wavelength optical signal, dividing the multi-wavelength optical signal into a plurality of sub-wavelength optical signals based on a preset wavelength range, and analyzing the plurality of sub-wavelength optical signals to output a physical quantity of light.

[0015] Other unspecified objects of the present invention may be further considered to the extent that they can be easily inferred from the following detailed description and effects.

[0016] According to one aspect of the present embodiment, the optical sensor system comprises a light source unit that emits light in a sensing mode selected from a plurality of sensing modes; a multi-signal optical sensor unit that generates a multi-wavelength optical signal by measuring a change in the amount of light received from the light source unit; a wavelength branching unit that divides the multi-wavelength optical signal into a plurality of sub-wavelength optical signals based on a preset wavelength range; and a signal analysis unit that analyzes the plurality of sub-wavelength optical signals and outputs an analysis result for the light.

[0017] The above-mentioned multi-signal optical sensor unit may include a Sagnac interferometer, a Mach-Zehnder interferometer, a Michelson interferometer, a Fabry-Perot interferometer, an optical fiber grating pair element, or a combination thereof.

[0018] The signal analysis unit may include a plurality of compensation elements connected to the wavelength branching unit, each compensating for a plurality of sub-wavelength optical signals. The plurality of compensation elements may include polarization control elements or phase control elements.

[0019] The signal analysis unit may include a plurality of linear optical filters connected to the wavelength branching unit or the plurality of compensation elements, each filtering the plurality of subwavelength optical signals or the compensated plurality of subwavelength optical signals.

[0020] The signal analysis unit may include a plurality of photodetectors connected to the wavelength branching unit, the plurality of compensation elements, or the plurality of linear optical filters, each detecting the plurality of subwavelength optical signals, the compensated plurality of subwavelength optical signals, or the filtered plurality of subwavelength optical signals and converting them into electrical signals.

[0021] The above signal analysis unit may include a signal processing unit connected to the plurality of photodetectors to analyze the electrical signal and output an analysis result for the light.

[0022] The above optical sensor system may include a direct light detector that detects light received from the light source, converts it into an electrical signal, and transmits the electrical signal to the signal processing unit.

[0023] The signal analysis unit may include a path connection unit that changes the sensing mode by establishing a connection between the plurality of compensation elements, the plurality of linear optical filters, and the plurality of photodetectors.

[0024] The signal analysis unit may include a signal control unit that generates a control signal to activate some of the plurality of compensation elements, the plurality of linear optical filters, and the plurality of photodetectors in the modified sensing mode.

[0025] The light source unit may include a simulated light source that generates light having a variable wavelength range based on a preset wavelength range according to a control signal of the signal control unit and activates a portion of the wavelength range of the light.

[0026] The above signal control unit can perform operation tests according to the variable wavelength range for some of the wavelength ranges of the simulated light source, the plurality of compensation elements, the plurality of linear optical filters, and the plurality of photodetectors that are activated, in accordance with the control signal of the above signal control unit.

[0027] In the first sensing mode among the plurality of sensing modes above, the path connecting unit connects the plurality of linear optical filters to the wavelength branching unit and connects the plurality of optical detectors to the plurality of linear optical filters, and the signal control unit can deactivate the direct optical detector.

[0028] In the second sensing mode among the plurality of sensing modes above, the path connecting unit connects the plurality of compensation elements to the wavelength branching unit, connects the plurality of linear optical filters to the plurality of compensation elements, connects the plurality of optical detectors to the plurality of linear optical filters, and the signal control unit can activate the direct optical detector.

[0029] In the third sensing mode among the plurality of sensing modes above, the path connection unit connects the plurality of photodetectors to the wavelength branching unit, and the signal control unit can activate the direct photodetector.

[0030] According to another aspect of the present embodiment, a method for analyzing optical sensor signals may include: selecting one sensing mode among a plurality of sensing modes; emitting light through a light source unit in the selected sensing mode; generating a multi-wavelength optical signal by measuring a change in the amount of light received from the light source unit through a multi-signal optical sensor unit; dividing the multi-wavelength optical signal into a plurality of sub-wavelength optical signals based on a preset wavelength range through a wavelength branching unit; analyzing the plurality of sub-wavelength optical signals through a signal analysis unit and outputting an analysis result for the light; changing from the selected sensing mode to another sensing mode; and conducting an operation test in the changed sensing mode.

[0031] As described above, according to the embodiments of the present invention, by measuring the amount of change of light received from a light source unit in one sensing mode selected among a plurality of sensing modes to generate a multi-wavelength optical signal, dividing the multi-wavelength optical signal into a plurality of sub-wavelength optical signals based on a preset wavelength range, and analyzing the plurality of sub-wavelength optical signals to output a physical quantity of light, the noise characteristics are improved, thereby enhancing resolution and reducing system costs.

[0032] Even if an effect is not explicitly mentioned herein, the effects described in the following specification and other effects that are expected by the technical features of the present invention and can be easily inferred are treated as described in the specification of the present invention.

[0033] Figure 1 is a diagram illustrating a signal analysis technique using a conventional single-wavelength optical signal.

[0034] Figure 2 is a diagram illustrating the optical power and wavelength processed by a signal analysis technology using a conventional single-wavelength optical signal.

[0035] FIGS. 3 and FIGS. 4 are block diagrams illustrating a light sensor system according to an embodiment of the present invention.

[0036] FIG. 5 is a diagram illustrating the optical spectrum characteristics, optical power, and multi-wavelength optical signals of an optical sensor processed by an optical sensor system according to one embodiment of the present invention.

[0037] FIGS. 6 to 8 are drawings illustrating a first sensing mode of an optical sensor system according to an embodiment of the present invention.

[0038] FIGS. 9 and FIGS. 10 are drawings illustrating a second sensing mode of an optical sensor system according to an embodiment of the present invention.

[0039] FIGS. 11 to 13 are drawings illustrating a third sensing mode of an optical sensor system according to an embodiment of the present invention.

[0040] FIGS. 14 and FIGS. 15 are drawings illustrating a fourth sensing mode of an optical sensor system for measuring alternating current voltage according to an embodiment of the present invention.

[0041] FIG. 16 is a flowchart of a method for analyzing optical sensor signals according to one embodiment of the present invention.

[0042] The present invention relates to an optical sensor system comprising: a light source unit that emits light in a sensing mode selected from a plurality of sensing modes; a multi-signal optical sensor unit that generates a multi-wavelength optical signal by measuring a change in the amount of light received from the light source unit; a wavelength branching unit that divides the multi-wavelength optical signal into a plurality of sub-wavelength optical signals based on a preset wavelength range; and a signal analysis unit that analyzes the plurality of sub-wavelength optical signals and outputs an analysis result for the light.

[0043] Hereinafter, in describing the present invention, detailed descriptions of related known functions are omitted if they are deemed obvious to a person skilled in the art and could unnecessarily obscure the essence of the invention, and some embodiments of the present invention are described in detail through exemplary drawings.

[0044] FIGS. 3 and 4 are block diagrams illustrating an optical sensor system according to an embodiment of the present invention, and FIG. 5 is a diagram illustrating the optical spectrum characteristics, optical power, and multi-wavelength optical signal of an optical sensor processed by an optical sensor system according to an embodiment of the present invention.

[0045] The optical sensor system according to the present embodiment uses multi-wavelength optical signals as they are, so unlike the prior art described with reference to FIGS. 1 and 2, it does not use additional optical components such as optical filters in the light source section, and it has the advantage of being able to lower system costs because it does not need to use additional expensive optical components such as optical amplifiers and optical isolators used to reduce noise generation.

[0046] The optical sensor system according to the present embodiment may utilize optical fiber elements such as optical fiber gratings. An optical sensor system using optical fiber elements can be used to measure various types of physical quantities, such as temperature, strain, vibration, and pressure. That is, in the case of an optical fiber sensor, an optical signal in the form of an optical band is mainly generated in the sensor section, and physical quantities are calculated using this. Depending on the physical quantity applied to the sensor section, such as temperature, strain, vibration, and pressure, the center (resonance) wavelength of the optical band shifts, and the physical quantity is calculated by measuring this.

[0047] The optical sensor system according to the present embodiment may apply an interferometer to the sensor section. An optical fiber sensor system using an interferometer as the sensor section may generate multiple band-shaped optical signals in the sensor section and use a method to calculate physical quantities by measuring the shift in the center wavelength or phase change of the signal light according to the physical quantity applied to the sensor section. Therefore, a measuring device is required to accurately and stably measure wavelength changes and calculate physical quantities therefrom. When the sensor section is configured using an interferometer such as a Sagnac interferometer, Mach-Zehnder interferometer, Michelson interferometer, Fabry-Perot interferometer, or optical fiber grating pair, there is an advantage in being able to measure the applied physical quantity with high sensitivity.

[0048] Referring to FIG. 3, the optical sensor system (10) may include a light source unit (100), a multi-signal optical sensor unit (200), a wavelength branching unit (300), and a signal analysis unit (400). The light source unit (100), the multi-signal optical sensor unit (200), the wavelength branching unit (300), and the signal analysis unit (400) may be interconnected to transmit and receive optical signals or data processed therefrom.

[0049] The light source unit (100) is a device that emits light in one of the multiple sensing modes selected from among the multiple sensing modes.

[0050] The multi-signal optical sensor unit (200) is a device that generates a multi-wavelength optical signal by measuring the amount of change of light received from the light source unit.

[0051] The wavelength branching unit (300) is a device that divides a multi-wavelength optical signal into multiple sub-wavelength optical signals based on a preset wavelength range.

[0052] The signal analysis unit (400) is a device that analyzes multiple subwavelength optical signals and outputs the analysis results for the light.

[0053] Referring to FIG. 4, the signal analysis unit (400) may include a plurality of compensation elements (421, 422, 423, 424) connected to the wavelength branching unit (300) or the path connecting unit (410) to compensate for a plurality of subwavelength optical signals. The plurality of compensation elements (421, 422, 423, 424) may include polarization control elements or phase control elements. For example, to compensate for subwavelength optical signals, a plurality (n) of polarization control elements may be used as the compensation elements to reduce noise by adjusting the azimuth angle or ellipticity of the polarization state of the optical signal branched by the wavelength branching unit (300) to have a different value of 2p / n. The polarization or phase of the optical signal emitted from the light source may be disturbed by disturbances such as banding vibrations applied from the outside, and this can be reduced by using a multi-wavelength optical signal and a plurality of compensation elements.

[0054] The signal analysis unit (400) may include a plurality of linear optical filters (431, 432, 433, 434) connected to a wavelength branching unit (300), a path connecting unit (410), or a plurality of compensation elements (421, 422, 423, 424) to filter a plurality of subwavelength optical signals or a plurality of compensated subwavelength optical signals, respectively.

[0055] The signal analysis unit (400) may include a plurality of photodetectors (441, 442, 443, 444) connected to a wavelength branching unit (300), a path connecting unit (410), a plurality of compensation elements (421, 422, 423, 424), or a plurality of linear optical filters (431, 432, 433, 434) to detect a plurality of subwavelength optical signals, a compensated plurality of subwavelength optical signals, or a filtered plurality of subwavelength optical signals, respectively, and convert them into electrical signals.

[0056] The signal analysis unit (400) may include a signal processing unit (450) connected to a plurality of photodetectors (441, 442, 443, 444) to analyze electrical signals and output analysis results for light.

[0057] The light sensor system (10) may include a direct light detector (445) that detects light received from a light source unit (100), converts it into an electrical signal, and transmits the electrical signal to a signal processing unit (450).

[0058] The signal analysis unit (400) may include a path connection unit (410) that changes the sensing mode by setting a connection path between a plurality of compensation elements (421, 422, 423, 424), a plurality of linear optical filters (431, 432, 433, 434), and a plurality of optical detectors (441, 442, 443, 444).

[0059] The signal analysis unit (400) may include a signal control unit (460) that generates a control signal to activate some of the plurality of compensation elements (421, 422, 423, 424), the plurality of linear optical filters (431, 432, 433, 434), and the plurality of optical detectors (441, 442, 443, 444) in a changed sensing mode.

[0060] The light source unit (100) includes a light source (110) and may include a simulated light source (120) that generates light having a variable wavelength range based on a preset wavelength range according to a control signal of the signal control unit (460) and activates a portion of the wavelength range of the light.

[0061] The signal control unit (460) can perform operation tests according to the control signal of the signal control unit for some of the activated parts of the simulated light source (120), a plurality of compensation elements (421, 422, 423, 424), a plurality of linear optical filters (431, 432, 433, 434), and a plurality of photodetectors (441, 442, 443, 444) according to the variable wavelength range for each preset wavelength range.

[0062] Referring to FIG. 5, the optical sensor system according to the present embodiment can reduce noise generation by using optical signals collected at multiple wavelengths. Since the noise characteristics are excellent, the resolution of the calculated data is high, allowing for the calculation of accurate physical quantities.

[0063] FIGS. 6 to 8 illustrate a first sensing mode of a light sensor system according to an embodiment of the present invention. For reference, the connection configuration of FIG. 6 may be formed not only with the selective activation of components according to the change in the sensing mode of FIG. 7, but also with a structure in which the direct light detector is removed.

[0064] In the first sensing mode among the multiple sensing modes, the path connecting unit (410) connects a plurality of linear optical filters (431, 432, 433, 434) to the wavelength branching unit (300), and connects a plurality of optical detectors (441, 442, 443, 444) to the plurality of linear optical filters (421, 422, 423, 424), and the signal control unit (460) is connected to a direct optical detector (445) and can deactivate the direct optical detector (445). Referring to FIG. 7 regarding the change in sensing mode, an example of a selectively activated component is indicated by a thick solid line. As shown in FIG. 8, the optical sensor system may apply an optical filter (Dielectric Filter) or an optical fiber filter having linear light transmission characteristics according to wavelength.

[0065] FIGS. 9 and FIGS. 10 are drawings illustrating a second sensing mode of an optical sensor system according to an embodiment of the present invention.

[0066] In the second sensing mode among the multiple sensing modes, the path connecting unit (410) connects a plurality of compensation elements (421, 422, 423, 424) to the wavelength branching unit (300), connects a plurality of linear optical filters (421, 422, 423, 424) to the plurality of compensation elements (421, 422, 423, 424), connects a plurality of optical detectors (441, 442, 443, 444) to the plurality of linear optical filters (421, 422, 423, 424), and the signal control unit (460) is connected to a direct optical detector (445) to activate the direct optical detector (445). Referring to FIG. 10 regarding the change in the sensing mode, an example of a selectively activated component is indicated by a thick solid line.

[0067] Multiple compensation elements may include polarization control elements or phase control elements.

[0068] The optical sensor system according to the present embodiment can reduce the instability of the light source and the transmission optical fiber on the optical path by using a compensation element.

[0069] Light sources used in optical sensor systems are polarization-dependent. In such cases, if a single-wavelength optical signal is used for signal analysis as in conventional technology, disturbances caused by the instability of the light source or by temperature and vibration in the transmission optical fibers along the optical path accumulate directly in the optical signal. To eliminate this, conventional technology faces the limitation of requiring the use of expensive light sources with linear polarization characteristics or polarization-maintaining optical fibers.

[0070] On the other hand, the optical sensor system according to the present embodiment can eliminate such instability and disturbance by using a polarization control element or a phase control element after the wavelength division element to control the respective polarization and phase, thereby enabling more accurate and stable optical signal analysis.

[0071] FIGS. 11 to 13 illustrate a third sensing mode of an optical sensor system according to an embodiment of the present invention. For reference, the connection configuration of FIG. 11 may be formed not only by selectively activating components according to the change in the sensing mode of FIG. 12, but also by removing a plurality of linear optical filters and the like, and directly connecting the high-resolution wavelength branching element of FIG. 13 to a plurality of photodetectors.

[0072] In the third sensing mode among the multiple sensing modes, the path connection unit (410) connects multiple photodetectors (441, 442, 443, 444) to the wavelength branching unit (300), and the signal control unit (450) is connected to the direct photodetector (445) to activate the direct photodetector (445). Referring to FIG. 12 regarding the change in sensing mode, examples of selectively activated components are indicated by thick solid lines. As shown in FIG. 13, the optical sensor system may apply a diffraction grating or an arrayed waveguide grating to the wavelength branching unit (300). As shown in FIG. 13, it is preferable to use a wavelength branching unit element having high resolution characteristics in the wavelength branching unit (300) for the optical sensor system.

[0073] FIGS. 14 and FIGS. 15 are drawings illustrating a fourth sensing mode of an optical sensor system according to an embodiment of the present invention.

[0074] The multi-signal optical sensor unit of the optical sensor system according to the present embodiment may include a Sagnac interferometer, a Mach-Zehnder interferometer, a Michelson interferometer, a Fabry-Perot interferometer, an optical fiber grating pair element, or a combination thereof. The optical sensor unit may be an optical element that creates periodic interference patterns in the wavelength domain, such as a Sagnac interferometer, a Mach-Zehnder interferometer, a Michelson interferometer, a Fabry-Perot interferometer, or an optical fiber grating pair element. FIG. 14 is a diagram illustrating an optical sensor system for measuring AC voltage according to an embodiment of the present invention. The optical sensor system shown in FIG. 14 is composed of a light source unit including a broadband light source, a multi-signal optical sensor unit including a piezoelectric cell, an optical fiber coupler, and a polarization controller, a wavelength branching unit, and a signal analysis unit. According to the present invention, the wavelength branching unit is configured to include a path connection unit and a compensation unit. An optical fiber for multi-signal sensing is wound around the piezoelectric cell. An alternating current voltage generated by an AC voltage generator is applied to the piezoelectric cell, and the piezoelectric cell expands due to the applied alternating current voltage, and the optical fiber wound around the piezoelectric cell detects the expansion of the piezoelectric cell. Referring to FIG. 14, the configuration of the optical fiber sensor composed of a Sagnac interferometer can be confirmed. Referring to Fig. 15, in the case of a fiber optic sensor composed of a Sagnac interferometer, optical signals are generated at multiple wavelengths, and by analyzing them simultaneously, the physical quantity (AC voltage signal) applied to the fiber optic sensor can be accurately calculated with high resolution.

[0075] FIG. 16 is a flowchart of a method for analyzing optical sensor signals according to one embodiment of the present invention.

[0076] The optical sensor signal analysis method can be performed by an optical sensor system, and each operation performed by the optical sensor system can be performed individually or in combination.

[0077] In S10, a step of selecting one sensing mode among multiple sensing modes is performed.

[0078] In S20, a step of emitting light through a light source unit is performed in the selected sensing mode.

[0079] In S30, a step is performed to generate a multi-wavelength optical signal by measuring the amount of change of light received from the light source unit through the multi-signal optical sensor unit.

[0080] In S40, a step is performed to divide a multi-wavelength optical signal into multiple sub-wavelength optical signals based on a preset wavelength range through a wavelength branching section.

[0081] In S50, a step is performed to analyze multiple subwavelength optical signals through a signal analysis unit and output an analysis result for the light.

[0082] In S60, a step is performed to change from the selected sensing mode to another sensing mode.

[0083] In the S70, the step of conducting an operation test in the changed sensing mode is performed.

[0084] Here, the multi-signal optical sensor unit may include a Sagnac interferometer, a Mach-Zehnder interferometer, a Michelson interferometer, a Fabry-Perot interferometer, an optical fiber grating pair element, or a combination thereof.

[0085] The step of changing the sensing mode (S60) may include changing the sensing mode by setting a connection path between a plurality of compensation elements, a plurality of linear optical filters, and a plurality of photodetectors through a path connection part.

[0086] Additionally, the step of changing the sensing mode (S60) may include the step of activating some of the plurality of compensation elements, plurality of linear optical filters, and plurality of photodetectors in the changed sensing mode through a control signal generated by the signal control unit.

[0087] The step (S70) of conducting an operation test in a changed mode may include the step of activating a simulated light source that generates light having a variable wavelength range based on a preset wavelength range through a signal control unit.

[0088] Additionally, the step (S70) of conducting an operation test in a changed mode may perform an operation test for some of the activated parts among a plurality of compensation elements, a plurality of linear optical filters, and a plurality of photodetectors through a signal control unit, according to a preset wavelength range according to a variable wavelength range.

[0089] In the first sensing mode among the multiple sensing modes, the path connection unit connects multiple linear optical filters to the wavelength branching unit, connects multiple photodetectors to the multiple linear optical filters, and the signal control unit can deactivate the direct photodetectors.

[0090] In the second sensing mode among the multiple sensing modes, the path connection unit connects multiple compensation elements to the wavelength branching unit, connects multiple linear optical filters to the multiple compensation elements, connects multiple photodetectors to the multiple linear optical filters, and the signal control unit can activate the direct photodetectors.

[0091] In the third sensing mode among the multiple sensing modes, the path connection unit connects multiple photodetectors to the wavelength branching unit, and the signal control unit can activate the direct photodetector.

[0092] The operation test step of the optical sensor signal analysis method can perform a first test and a second test.

[0093] The first test result (T1) performed by the optical sensor signal analysis method can be set to satisfy Equation 1.

[0094] [Mathematical Formula 1]

[0095]

[0096] K is a transformation factor for matching the sum of the measurements along the path through a direct photodetector and the measurements along the path through multiple photodetectors. In other words, it is a scaling value for normalizing the test range.

[0097] W S is the wavelength range of the light source, and M DD is the magnitude of the electrical signal of the direct photodetector, and W SS is the individual wavelength range of the simulated light source, and M D is the magnitude of the electrical signal of each photodetector.

[0098] The second test result (T2) performed by the optical sensor signal analysis method can be set to satisfy Equation 2.

[0099] [Mathematical Formula 2]

[0100]

[0101] K is a transformation factor for matching the sum of the measurements along the path through a direct photodetector and the measurements along the path through multiple photodetectors. In other words, it is a scaling value for normalizing the test range.

[0102] W S is the wavelength range of the light source, and M DD is the magnitude of the electrical signal of the direct photodetector, and W SS is the individual wavelength range of the simulated light source, and M D is the magnitude of the electrical signal of each photodetector.

[0103] K1 is a first weight that considers a numerically set compensation coefficient for the compensation degree of each compensation element, and K2 is a second weight that considers a numerically set filtering coefficient for the filtering degree of each linear optical filter.

[0104] The optical sensor signal analysis method compares T1 and T2, and through the comparison between T1 and T2, the test error of the multi-wavelength optical signal analysis of the optical sensor system according to the compensation coefficient and filtering coefficient can be estimated. Therefore, it was easy to determine that the test error of the multi-wavelength optical signal analysis of the optical sensor system according to the compensation coefficient and filtering coefficient can be improved (approximately 5~10%).

[0105] According to the optical sensor signal analysis method, in the case of an interferometric optical sensor that generates multiple wavelength optical signals, noise generated by using multiple signals simultaneously can be significantly reduced, and the resolution and accuracy of the physical quantity calculated therefrom can be increased.

[0106] According to the optical sensor signal analysis method, it has the advantage of lowering system costs because it does not require the use of expensive optical components such as high-power light sources, optical amplifiers, and optical isolators that are necessary to reduce noise.

[0107] According to the optical sensor signal analysis method, it can be utilized in optical sensors generating multiple signals and optical sensor systems using laser light sources, such as Sagnac interferometers, Michelson interferometers, Mach-Zehnder interferometers, Fabry-Perot interferometers, array fiber optic grating sensors, and optical sensor systems based on multichannel laser light sources.

[0108] The optical sensor system (10) may include a processing unit, a storage unit, and a communication bus.

[0109] The processing unit can control the optical sensor system (10) to operate. For example, the processing unit can execute one or more programs stored in the storage unit. One or more programs may include one or more computer-executable instructions, and the computer-executable instructions may be configured to cause the optical sensor system (10) to perform operations according to exemplary embodiments when executed by the processing unit.

[0110] The storage unit is configured to store computer-executable instructions or program code, program data and / or other suitable forms of information. Computer-executable instructions or program code, program data and / or other suitable forms of information may also be provided through an input / output interface or a communication interface. A program stored in the storage unit includes a set of instructions executable by a processing unit. In one embodiment, the storage unit may be a memory (volatile memory such as random access memory, non-volatile memory, or a suitable combination thereof), one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, or other forms of storage media that are accessed by the optical sensor system (10) and capable of storing desired information, or a suitable combination thereof.

[0111] The communication bus interconnects various other components of the optical sensor system (10).

[0112] The optical sensor system (10) may also include one or more input / output interfaces and one or more communication interfaces that provide interfaces for one or more input / output devices. The input / output interfaces and communication interfaces are connected to a communication bus. Input / output devices (not shown) may be connected to other components of the optical sensor system (10) through the input / output interfaces.

[0113] The optical sensor system (10) may be implemented in a logic circuit by hardware, firmware, software, or a combination thereof, and may be implemented using a general-purpose or specific-purpose computer. The device may be implemented using a hardwired device, a field programmable gate array (FPGA), an application-specific integrated circuit (ASIC), etc. Additionally, the device may be implemented as a system on chip (SoC) including one or more processors and controllers.

[0114] The optical sensor system (10) may be installed in a computing device or server equipped with hardware elements in the form of software, hardware, or a combination thereof. The computing device or server may refer to various devices including, in whole or in part, a communication device such as a communication modem for communicating with various devices or wired / wireless communication networks, a memory for storing data for executing a program, and a microprocessor for executing a program to perform calculations and commands.

[0115] Although FIG. 16 describes each process as being executed sequentially, this is merely an illustrative description, and a person skilled in the art may modify and adapt the process in various ways without departing from the essential characteristics of the embodiment of the present invention, such as changing the order described in FIG. 16, executing one or more processes in parallel, or adding other processes.

[0116] Operations according to the embodiments may be implemented in the form of program instructions that can be executed through various computer means and recorded on a computer-readable medium. A computer-readable medium refers to any medium that participates in providing instructions to a processor for execution. A computer-readable medium may include program instructions, data files, data structures, or a combination thereof. Examples include magnetic media, optical recording media, memory, etc. Computer programs may be distributed over networked computer systems, and computer-readable code may be stored and executed in a distributed manner. Functional programs, code, and code segments for implementing the embodiments may be easily deduced by programmers skilled in the art to which the embodiments belong.

[0117] These embodiments are intended to explain the technical concept of the present embodiment, and the scope of the technical concept of the present embodiment is not limited by these embodiments. The scope of protection of the present embodiment shall be interpreted by the claims below, and all technical concepts within an equivalent scope shall be interpreted as being included within the scope of rights of the present embodiment.

[0118] [Explanation of the symbol]

[0119] 10: Optical sensor system

[0120] 100: Light source

[0121] 200: Multi-signal optical sensor unit

[0122] 300: Wavelength branch

[0123] 400: Signal Analysis Unit

[0124] The technical field to which the present invention belongs relates to a technology for analyzing optical signals generated from an optical sensor, and more specifically, to an optical sensor signal analysis method and an optical sensor system using the same, which enables more accurate analysis by using multiple signals generated from an optical sensor and can calculate more accurate physical quantity data from the optical signals generated from the optical sensor.

Claims

1. In an optical sensor system, A light source unit that emits light in one sensing mode selected from a plurality of sensing modes; A multi-signal optical sensor unit that generates a multi-wavelength optical signal by measuring the amount of change of light received from the light source unit; A wavelength branching unit that divides the above multi-wavelength optical signal into a plurality of sub-wavelength optical signals based on a preset wavelength range; and An optical sensor system comprising a signal analysis unit that analyzes a plurality of subwavelength optical signals and outputs an analysis result for the light.

2. In Paragraph 1, The above-mentioned multi-signal optical sensor unit is, An optical sensor system comprising a Sagnac interferometer, a Mach-Zehnder interferometer, a Michelson interferometer, a Fabry-Perot interferometer, a fiber optic grating pair element, or a combination thereof.

3. In Paragraph 1, The above signal analysis unit is, A plurality of compensation elements connected to the wavelength branching section and each compensating the plurality of sub-wavelength optical signals; A plurality of linear optical filters connected to the wavelength branching section or the plurality of compensation elements, each filtering the plurality of subwavelength optical signals or the compensated plurality of subwavelength optical signals; A plurality of photodetectors connected to the wavelength branching section, the plurality of compensation elements, or the plurality of linear optical filters, each detecting the plurality of subwavelength optical signals, the compensated plurality of subwavelength optical signals, or the filtered plurality of subwavelength optical signals and converting them into electrical signals; and It includes a signal processing unit connected to the plurality of photodetectors above, which analyzes the electrical signal and outputs the analysis result for the light. The optical sensor system described above includes a direct light detector that detects light received from the light source, converts it into an electrical signal, and transmits the electrical signal to the signal processing unit.

4. In Paragraph 3, The above plurality of compensation elements are, A photosensor system comprising a polarization control element or a phase control element.

5. In Paragraph 3, The above signal analysis unit is, A path connection unit that changes the sensing mode by establishing a connection between the plurality of compensation elements, the plurality of linear optical filters, and the plurality of photodetectors; and An optical sensor system comprising a signal control unit that generates a control signal for activating some of the plurality of compensation elements, the plurality of linear optical filters, and the plurality of photodetectors in the above-mentioned modified sensing mode.

6. In Paragraph 5, The above light source unit is, It includes a simulated light source that generates light having a variable wavelength range based on a preset wavelength range according to a control signal of the signal control unit and activates a portion of the wavelength range of the light. The above signal control unit is, An optical sensor system that performs operation tests according to the preset wavelength ranges for some of the activated parts of the simulated light source, the plurality of compensation elements, the plurality of linear optical filters, and the plurality of photodetectors according to the variable wavelength range, based on the control signal of the signal control unit.

7. In Paragraph 5, In the first sensing mode among the plurality of sensing modes above, The above path connecting portion connects the plurality of linear optical filters to the wavelength branching portion, and connects the plurality of optical detectors to the plurality of linear optical filters. The above signal control unit deactivates the above direct light detector, and In the second sensing mode among the above plurality of sensing modes, The above path connecting portion connects the plurality of compensation elements to the wavelength branching portion, connects the plurality of linear optical filters to the plurality of compensation elements, and connects the plurality of photodetectors to the plurality of linear optical filters. The above signal control unit activates the above direct light detector, and In the third sensing mode among the plurality of sensing modes above, A light sensor system in which the path connecting portion connects the plurality of light detectors to the wavelength branching portion, and the signal control portion activates the direct light detector.

8. In the method for analyzing optical sensor signals, A step of selecting one sensing mode among a plurality of sensing modes; A step of emitting light through a light source in the above-mentioned selected sensing mode; A step of generating a multi-wavelength optical signal by measuring the amount of change of light received from the light source unit through a multi-signal optical sensor unit; A step of dividing the multi-wavelength optical signal into a plurality of sub-wavelength optical signals based on a preset wavelength range through a wavelength branching section; A step of analyzing the plurality of subwavelength optical signals through a signal analysis unit and outputting an analysis result for the light; A step of changing from the selected sensing mode to another sensing mode; and A method for analyzing optical sensor signals, comprising the step of conducting an operation test in the above-mentioned modified sensing mode.

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