Flame detection system

Abstract

To make it possible to determine the degree of deterioration of a measurement unit in a flame detection system.SOLUTION: A flame detection system in accordance with the present invention includes a measurement unit that measures the intensity of light using a sensor, a flame detection unit that detects flame on the basis of the intensity of light measured by the measurement unit, and a degree-of-deterioration determination unit that calculates an index of variance in the intensity of light measured by the measurement unit, and determines the degree of deterioration of the measurement unit on the basis of the index of variance. The degree-of-deterioration determination unit included in the flame detection system in accordance with the present invention may estimate, based on a chronological change in the index of variance over a previous predetermined period, the timing when the index of variance in the intensity of light measured by the measurement unit reaches a predetermined threshold, and determine the degree of deterioration of the measurement unit on the basis of the timing.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a technique for maintaining a flame detection system.

Background Art

[0002] There are cases where a disaster prevention system may malfunction due to deterioration. Various techniques have been proposed to prevent such inconveniences. For example, in Patent Document 1, when a fire is detected, the current value flowing through a signal line connecting a terminal device that outputs a fire signal to a disaster prevention receiving panel and the disaster prevention receiving panel is monitored, and when the current value changes significantly, it is determined as a sign of a failure caused by insulation deterioration of the signal line, etc., and a disaster prevention system having a function of outputting a sign warning is proposed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] There is a flame detection system that detects a flame with a sensor that is sensitive to the light emitted by the flame. One of the causes of the malfunction of such a flame detection system is the deterioration of the components of the measurement unit that measures the light intensity with the sensor. For example, when the sensor of the measurement unit provided in the flame detection system deteriorates, the amplitude value of the signal output from the sensor may show irregular fluctuations regardless of the presence or absence of light. Also, when the amplifier that amplifies the signal generated by the sensor deteriorates, the amplitude value of the signal from the sensor amplified by the amplifier may constantly show a high value regardless of the presence or absence of light.

[0005] As the components deteriorate as described above, the accuracy of the flame detection determination performed by the flame detection system decreases. Therefore, if the degree of deterioration of the measurement unit can be known, the accuracy of the flame detection determination required for the flame detection system can be maintained by replacing components or the like.

[0006] In view of such circumstances, an object of the present invention is to enable knowing the degree of deterioration of the measurement unit of a flame detection system.

Means for Solving the Problems

[0007] To solve the above problems, the present invention provides, as a first aspect, a flame detection system including a measurement unit that measures the intensity of light by a sensor, a flame detection unit that detects a flame based on the intensity of light measured by the measurement unit, a stable period specifying unit that specifies a period during which environmental factors that affect the measurement result of the measurement unit are stable, and a storage unit that stores, as data indicating noise, data indicating the intensity of light measured by the measurement unit during the period specified by the stable period specifying unit.

[0008] According to the flame detection system according to the first aspect, the degree of deterioration of the measurement unit of the flame detection system can be known from the noise indicated by the stored data.

[0009] In the flame detection system according to the first aspect, a configuration may be adopted as a second aspect in which the stable period specifying unit specifies a period during which environmental factors are stable based on the measurement result of the measurement unit.

[0010] According to the flame detection system according to the second aspect, it is not necessary to separately provide a sensor to specify a period during which environmental factors are stable.

[0011] In the flame detection system according to the first aspect, when the sensor is a first sensor, a second sensor different from the first sensor that measures the ambient physical quantity is provided, and the stable period specifying unit specifies a period during which environmental factors are stable based on the measurement result of the second sensor. A configuration may be adopted as a third aspect.

[0012] According to the flame detection system according to the third aspect, by providing the second sensor, it is possible to exclude the period during which the first sensor is stably irradiated with ambient light from the period during which the environmental factors are stable. Therefore, compared with the case where the second sensor is not provided, the reliability of the data indicating the noise stored is high.

[0013] In the flame detection system according to the third aspect, a configuration in which the second sensor is a sensor included in a device of the same type as the measurement unit disposed within a range of a predetermined distance from the measurement unit may be adopted as the fourth aspect.

[0014] For example, when there is an existing flame detection system including a plurality of measurement units of the same type arranged at intervals along the traveling direction of a vehicle, by specifying the period during which the environmental factors of a certain measurement unit are stable using the sensors of other measurement units arranged near that measurement unit, the flame detection system according to the fourth aspect can be realized without physically modifying the existing flame detection system.

[0015] In the flame detection system according to any one of the first to fourth aspects, a thermometer for measuring temperature and a correction unit for correcting the intensity of light measured by the measurement unit during the period specified by the stabilization period specifying unit based on the temperature measured by the thermometer are provided, and the storage unit stores the data indicating the intensity after correction by the correction unit as data indicating noise. Such a configuration may be adopted as the fifth aspect.

[0016] According to the flame detection system according to the fifth aspect, even when the intensity of light measured by the measurement unit causes an error due to the influence of temperature, the reliability of the data indicating noise is maintained.

[0017] Further, the present invention may adopt, as the sixth aspect, a configuration including a degradation degree determination unit that determines the degradation degree of the measurement unit based on the change over time of the noise indicated by the data stored in the storage unit in the flame detection system according to any one of the first to fifth aspects.

[0018] According to the flame detection system according to the sixth aspect, the degree of deterioration of the measurement unit of the flame detection system is determined.

Effect of the Invention

[0019] According to the present invention, the degree of deterioration of the measurement unit of the flame detection system can be known.

Brief Description of the Drawings

[0020]

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[0021] [Embodiment] Hereinafter, a flame detection system 1 according to an embodiment of the present invention will be described. FIG. 1 is a diagram showing the overall configuration of the flame detection system 1. The flame detection system 1 is a system for detecting flames generated in the tunnel TN.

[0022] The flame detection system 1 includes n flame detectors, namely, flame detectors 11(1), 11(2), 11(3), ···, 11(n), which are installed at substantially equal intervals along the traveling direction of the vehicle inside the tunnel TN. Hereinafter, these n flame detectors will be collectively referred to as the flame detector 11.

[0023] Substantially two flame detectors are integrated into each of the flame detectors 11. Specifically, the flame detector 11 integrates a flame detector (hereinafter referred to as the "right flame detector") that monitors a predetermined area on the right side as viewed from the flame detector 11 and a flame detector (hereinafter referred to as the "left flame detector") that monitors a predetermined area on the left side.

[0024] The tunnel TN is divided into monitoring areas A(1), A(2), A(3), ···, A(n - 1). Hereinafter, these (n - 1) monitoring areas will be collectively referred to as the monitoring area A. Each of the monitoring areas A is redundantly monitored by two adjacent flame detectors 11. For example, the monitoring area A(1) is monitored by the left flame detector of the flame detector 11(1) and the right flame detector of the flame detector 11(2). Therefore, even if one of the two adjacent flame detectors 11 fails, the monitoring of the monitoring area A will not be interrupted unless the other also fails simultaneously.

[0025] In addition to the flame detector 11, the flame detection system 1 includes a disaster prevention receiving panel 12 communicatively connected to each of the flame detectors 11, a server device 13 communicatively connected to the disaster prevention receiving panel 12, and a terminal device 14 capable of communicating with the server device 13.

[0026] Figure 2 is a diagram schematically showing the hardware configuration of the flame detector 11. The flame detector 11 includes a computer 101, four sensors connected to the computer 101, namely, sensor 111R, sensor 112R, sensor 111L, sensor 112L, four amplifiers corresponding to each of the four sensors, namely, amplifier 113R, amplifier 114R, amplifier 113L, amplifier 114L, and a thermometer 115 connected to the computer 101.

[0027] Sensors 111R and 112R are optical sensors for monitoring the right monitoring area A as viewed from the flame detector 11. Sensors 111L and 112L are optical sensors for monitoring the left monitoring area A as viewed from the flame detector 11.

[0028] Sensors 111R and 111L are long-wavelength optical sensors that respond with high sensitivity to the wavelength band on the long-wavelength side emitted by a flame (heat source). As sensors 111R and 111L, for example, optical sensors using pyroelectric elements are employed. Hereinafter, sensors 111R and 111L are collectively referred to as sensor 111.

[0029] Sensors 112R and 112L are short-wavelength optical sensors that respond with high sensitivity to the wavelength band on the short-wavelength side emitted by a flame (heat source). As sensors 112R and 112L, for example, optical sensors using photodiodes are employed. Hereinafter, sensors 112R and 112L are collectively referred to as sensor 112.

[0030] Amplifier 113R is connected between the computer 101 and sensor 111R and amplifies the signal generated when sensor 111R senses light. Amplifier 114R is connected between the computer 101 and sensor 112R and amplifies the signal generated when sensor 112R senses light. Amplifier 113L is connected between the computer 101 and sensor 111L and amplifies the signal generated when sensor 111L senses light. Amplifier 114L is connected between the computer 101 and sensor 112L and amplifies the signal generated when sensor 112R senses light.

[0031] The sensor 111R, the amplifier 113R, the wiring and contacts connecting them, and the wiring and contacts connecting the amplifier 113R and the computer 101 constitute one measurement unit. Also, the sensor 112R, the amplifier 114R, the wiring and contacts connecting them, and the wiring and contacts connecting the amplifier 114R and the computer 101 constitute one measurement unit. Also, the sensor 111L, the amplifier 113L, the wiring and contacts connecting them, and the wiring and contacts connecting the amplifier 113L and the computer 101 constitute one measurement unit. Also, the sensor 112L, the amplifier 114L, the wiring and contacts connecting them, and the wiring and contacts connecting the amplifier 114L and the computer 101 constitute one measurement unit.

[0032] In the following description, when referring to a signal output from the sensor 111 or the sensor 112, unless otherwise specified, it means a signal output from the sensor 111 or the sensor 112 and amplified by the amplifier 113 or the amplifier 114.

[0033] The thermometer 115 measures the temperature inside the housing of the flame detector 11 and outputs temperature data indicating the measured temperature to the computer 101.

[0034] The computer 101 includes a processor 1011 that performs data processing according to a program, a memory 1012 that stores various data including the program, an input / output interface 1013 that receives signal inputs from four sensors via four amplifiers and receives temperature data from the thermometer 115, and a communication interface 1014 that performs data communication with the disaster prevention receiving panel 12.

[0035] Note that in addition to the components shown in FIG. 2, the flame detector 11 includes components such as an A / D converter that converts the analog signals output from the four sensors into digital signals. However, since they are not related to the features of the present invention, they are omitted in FIG. 2 and their description is also omitted in the following explanation.

[0036] FIG. 3 is a diagram schematically showing the functional configuration of the flame detector 11. That is, when the processor 1011 of the computer 101 executes processing according to the program according to the present embodiment, the flame detector 11 including the determination device indicated by reference numeral 116 in FIG. 3 is realized. Hereinafter, the functional configuration of the determination device 116 will be described.

[0037] The determination device 116 includes a determination device 116R that determines flame detection using the signals output from the sensor 111R and the sensor 112R, and a determination device 116L that determines flame detection using the signals output from the sensor 111L and the sensor 112L. Since the configurations of the determination device 116R and the determination device 116L are common, hereinafter, as an example, the configuration of the determination device 116R will be described, and the description of the configuration of the determination device 116L will be omitted.

[0038] The determination device 116R includes a storage unit 1161R, an acquisition unit 1162R, a correction unit 1163R, a steady-state period specifying unit 1164R, a flame detection unit 1165R, a transmission / reception unit 1166R, and a timing unit 1167R.

[0039] The storage unit 1161R is realized by the memory 1012 that operates under the control of the processor 1011. The storage unit 1161R stores various data. The data stored in the storage unit 1161R includes a measurement value log table, a temperature correction constant table, and steady-state correction constant data.

[0040] FIG. 4 is a diagram illustrating the configuration of the measurement value log table. The measurement value log table is prepared according to each of the sensors 111R and 112R. In the measurement value log table, columns for "time", "temperature", "intensity (measured)", "intensity (after temperature correction)", and "intensity (after steady-state correction)" are provided. In the "time" column, the time measured by the timer unit 1167R when a signal is output from the sensor is stored. In the "temperature" column, the temperature measured by the thermometer 115 when a signal is output from the sensor is stored. In the "intensity (measured)" column, the amplitude value of the signal output from the sensor is stored. In the "intensity (after temperature correction)" column, a value obtained by correcting the amplitude value stored in the "intensity (measured)" column using the temperature correction constant described later by the correction unit 1163R is stored. In the "intensity (after steady-state correction)" column, a value obtained by correcting the amplitude value stored in the "intensity (after temperature correction)" column using the steady-state correction constant described later by the correction unit 1163R is stored.

[0041] FIG. 5 is a diagram illustrating the configuration of the temperature correction constant table. The temperature correction constant table is prepared according to each of the sensors 111R and 112R. In the temperature correction constant table, columns for "temperature" and "temperature correction constant" are provided. Various temperatures are stored in the "temperature" column. In the "temperature correction constant" column, the temperature correction constant corresponding to the temperature stored in the "temperature" column is stored. A bias due to the influence of temperature is applied to the amplitude value of the signal generated by the sensors 111R and 112R. The temperature correction constant is a value for canceling the bias due to the influence of temperature by subtracting it from the amplitude value of the signal generated by the sensor 111R or 112R, and is a value measured in advance by an experiment using the sensor 111R or 112R.

[0042] The steady-state positive compensation constant data is data indicating the steady-state positive compensation constant. In addition to the bias due to the influence of the temperature described above, a bias independent of the temperature is also applied to the amplitude values of the signals generated by the sensors 111R and 112R. The steady-state positive compensation constant is a value for canceling the bias independent of the temperature by subtracting it from the amplitude value of the signal generated by the sensor 111R or the sensor 112R. In the present embodiment, the average value of the amplitude values indicated by the dark noise data described later is used as the steady-state positive compensation constant.

[0043] Continue the description of the functional configuration of the flame detector 11 (Figure 3). The acquisition unit 1162R is realized by the input / output interface 1013 that operates under the control of the processor 1011. The acquisition unit 1162R continuously acquires the signal output from the sensor 111R and the signal output from the sensor 112R. The amplitude values of those signals acquired by the acquisition unit 1162R are stored in the measurement value log table together with the time and temperature at that time.

[0044] The correction unit 1163R is realized by the processor 1011. When new data is stored in the "time", "temperature", and "intensity (measured)" columns of the measurement value log table, the correction unit 1163R refers to the temperature positive compensation constant table, specifies the temperature positive compensation constant corresponding to the temperature stored in the "temperature" column, and stores the value obtained by subtracting the temperature positive compensation constant from the amplitude value stored in the "intensity (measured)" column in the "intensity (after temperature correction)" column. Subsequently, the correction unit 1163R stores the value obtained by subtracting the steady-state positive compensation constant from the value stored in the "intensity (after temperature correction)" column in the "intensity (after steady-state correction)" column.

[0045] The stabilization period specifying unit 1164R is realized by the processor 1011. For each of the sensors 111R and 112R, based on the data stored in the measurement value log table corresponding to those sensors, the stabilization period specifying unit 1164R specifies the period during which the environmental factors affecting the measurement results of those sensors are stable (hereinafter referred to as the "stabilization period").

[0046] FIG. 6 is a graph for explaining a method by which the steady-state period specifying unit 1164R specifies a steady-state period. The graph of FIG. 6 shows the change over time of the light intensity indicated by the amplitude value stored in the "Intensity (measured)" column of the measurement value log table according to, for example, the sensor 111. Note that since the graph of FIG. 6 is a graph for a short period of about several minutes, instead of the amplitude value stored in the "Intensity (measured)" column, the value stored in the "Intensity (after temperature correction)" column or the "Intensity (after steady-state correction)" column may be used.

[0047] Based on the data stored in the measurement value log table, the steady-state period specifying unit 1164R specifies, as the steady-state period, a period during which the state where the intensity fluctuation continuously remains within a predetermined threshold value continues for a predetermined time (for example, 1 minute) or more. In the case of the example of the graph of FIG. 6, the steady-state period specifying unit 1164R specifies the period Q1 as the steady-state period.

[0048] The description of the functional configuration of the flame detector 11 (FIG. 3) will be continued. The flame detection unit 1165R is realized by the processor 1011. The flame detection unit 1165R refers to the measurement value log table, and when it determines that the amplitude value of the signal output from the sensor 111R (the value in the "Intensity (after steady-state correction)" column) and the amplitude value of the signal output from the sensor 112R (the value in the "Intensity (after steady-state correction)" column) satisfy a predetermined condition, it causes the storage unit 1161R to store data indicating that a flame has been detected. Further, when the flame detection unit 1165R determines that the condition is not satisfied, it causes the storage unit 1161R to store data indicating that no flame has been detected.

[0049] Examples of the conditions used by the flame detection unit 1165R for flame detection determination are shown below. (Condition 1) The amplitude value of the signal output from the sensor 111R is equal to or greater than the threshold value T1. (Condition 2) The amplitude value of the signal output from the sensor 112R is equal to or greater than the threshold value T2. (Condition 3) The ratio of the amplitude value of the signal output from the sensor 111R to the amplitude value of the signal output from the sensor 112R is equal to or greater than the threshold value T3 and equal to or less than the threshold value T4 (however, T3 < T4).

[0050] When all of the above conditions 1 to 3 are satisfied a predetermined number of times or more within a predetermined time period in the past (for example, 10 seconds), the fire detection unit 1165R determines that a fire has occurred.

[0051] The transmission / reception unit 1166R is realized by a communication interface 1014 that operates under the control of the processor 1011. While data indicating that a fire has been detected is stored in the storage unit 1161R, the transmission / reception unit 1166R continuously outputs a fire detection signal to the disaster prevention receiving panel 12. Also, among the data stored in the measurement value log table, the data during the stable period specified by the stable period specifying unit 1164R is output to the disaster prevention receiving panel 12 as data indicating noise (hereinafter referred to as "dark vision noise data").

[0052] In addition, the transmission / reception unit 1166R receives the steady-state correction constant data transmitted from the disaster prevention receiving panel 12. The steady-state correction constant data received by the transmission / reception unit 1166R overwrites the steady-state correction constant data already stored in the storage unit 1161R.

[0053] The timing unit 1167R is realized by the processor 1011. The timing unit 1167R continuously measures the elapsed time from the reference time, specifies the current time, and generates a time signal indicating the specified current time.

[0054] The disaster prevention receiving panel 12 (FIG. 1) that constitutes the fire detection system 1 is installed in the tunnel TN, and when it receives a fire detection signal from the fire detector 11, it alerts people around by display and sound, and notifies the server device 13 that a fire has been detected. In addition to such general functions of a disaster prevention receiving panel, the disaster prevention receiving panel 12 has a function of determining the degree of deterioration of the fire detector 11 based on the dark vision noise data output from the fire detector 11.

[0055] FIG. 7 is a diagram schematically showing the hardware configuration of the disaster prevention receiving panel 12. The disaster prevention receiving panel 12 includes a computer 102, a display 121 and an operation unit 122 connected to the computer 102.

[0056] The computer 102 includes a processor 1021 that performs data processing according to a program, a memory 1022 that stores various data including the program, an input / output interface 1023 that inputs and outputs signals between the display 121 and the operation unit 122, and a communication interface 1024 that performs data communication between the n flame detectors 11 and the server device 13.

[0057] FIG. 8 is a diagram schematically showing the functional configuration of the disaster prevention receiving board 12. That is, when the processor 1021 of the computer 102 executes processing according to the program according to the present embodiment, the disaster prevention receiving board 12 including the degradation degree determination device indicated by reference numeral 123 in FIG. 8 is realized. Hereinafter, the functional configuration of the degradation degree determination device 123 will be described.

[0058] The degradation degree determination device 123 includes a storage unit 1231, an acquisition unit 1232, a degradation degree determination unit 1233, a transmission unit 1234, a display control unit 1235, and an operation reception unit 1236.

[0059] The storage unit 1231 is realized by the memory 1022 that operates under the control of the processor 1021 and stores various data. For example, the dark vision noise data transmitted from the flame detector 11 and acquired by the acquisition unit 1232 is stored in the storage unit 1231. FIG. 9 is a diagram illustrating the configuration of a table (hereinafter referred to as the "dark vision noise table") stored by the storage unit 1231 for storing the dark vision noise data. In the storage unit 1231, a dark vision noise table corresponding to each of the four sensors is stored for each of the plurality of flame detectors 11.

[0060] The dark vision noise table is provided with items such as a "date and time" column, a "dark vision noise data" column, an "average value" column, a "standard deviation" column, and a "data anomaly" column. In the "date and time" column, for example, the date and time of the first day of the dark vision period indicated by the dark vision noise data are stored. Also, in the "dark vision noise data" column, the dark vision noise data is stored. Note that since each individual dark vision noise data is data extracted in part from the measurement value log table (Figure 4), it includes multiple records. In the "average value" column, the average value of the values stored in the "intensity (after temperature correction)" column of the dark vision noise data is stored. In the "standard deviation" column, the standard deviation of the values stored in the "intensity (after temperature correction)" column of the dark vision noise data is stored. In the "data anomaly" column, data indicating whether the dark vision noise data stored in the "dark vision noise data" column is abnormal data is stored.

[0061] Return to the description of the functional configuration of the disaster prevention receiver 12 (Figure 8). The acquisition unit 1232 is realized by the communication interface 1024 operating under the control of the processor 1021. The acquisition unit 1232 acquires the flame detection signal and the dark vision noise data from each of the n flame detectors 11. The dark vision noise data acquired by the acquisition unit 1162 is stored in the dark vision noise table.

[0062] The degradation degree determination unit 1233 is realized by the processor 1021. When new dark vision noise data is stored in any of the dark vision noise tables, the degradation degree determination unit 1233 calculates the average value and the standard deviation of the values stored in the "intensity (after temperature correction)" column of the dark vision noise data and stores them in the corresponding columns of the dark vision noise table. Also, the degradation degree determination unit 1233 determines, among the dark vision noise data stored in the dark vision noise table, those whose average value or standard deviation deviates from the average value or standard deviation of other dark vision noise data before and after by a predetermined threshold or more as abnormal data, and stores data indicating the determination result in the "data anomaly" column.

[0063] Further, the degradation degree determination unit 1233 performs the following determination and estimation for each of the four sensors of each of the plurality of flame detectors 11, based on the data stored in the low-light noise table corresponding to those sensors (excluding the data of the records in which the data indicating that the data is abnormal is stored in the "data abnormality" column).

[0064] (1) If the average value of the intensities indicated by the most recent low-light noise data is equal to or greater than a predetermined threshold value A1, it is determined that component replacement is necessary. Also, it is estimated that the component to be replaced is the amplifier. (2) If the standard deviation of the intensities indicated by the most recent low-light noise data is equal to or greater than a predetermined threshold value B1, it is determined that component replacement is necessary. Also, it is estimated that the component to be replaced is the sensor. (3) If the day when the average value of the intensities, estimated based on the change over time of the average value of the intensities indicated by the low-light noise data in a past predetermined period, reaches the predetermined threshold value A1 is within a predetermined number of days from the present, it is determined that component replacement will be necessary soon. Also, it is estimated that the component to be replaced is the amplifier. (4) If the day when the standard deviation of the intensities, estimated based on the change over time of the standard deviation of the intensities indicated by the low-light noise data in a past predetermined period, reaches the predetermined threshold value B1 is within a predetermined number of days from the present, it is determined that component replacement will be necessary soon. Also, it is estimated that the component to be replaced is the sensor.

[0065] FIG. 10 and FIG. 11 are graphs for explaining the method by which the degradation degree determination device 123 performs the above determination and estimation. The graphs in FIGS. 10(a) and 11(a) are curves approximating the points corresponding to the values in the "date and time" column and the "average value" column of the low-light noise table. Note that the solid line portion of the curve indicates the transition of the average value up to the present, and the dashed-dotted line portion indicates the predicted transition of the average value in the future.

[0066] The graphs in FIGS. 10(b) and 11(b) are curves approximating the points corresponding to the values in the "date and time" column and the "standard deviation" column of the low-light noise table. Note that the solid line portion of the curve indicates the transition of the standard deviation up to the present, and the dashed-dotted line portion indicates the predicted transition of the standard deviation in the future.

[0067] The graph of Fig. 10(a) shows that at the current date and time d1, the average value of the intensity indicated by the scotopic noise data has not reached the threshold value A1. Also, the graph of Fig. 10(b) shows that at the current date and time d1, the standard deviation of the intensity indicated by the scotopic noise data has not reached the threshold value B1. Therefore, based on these data, the degradation degree determination unit 1233 determines that the sensor corresponding to these data or the amplifier connected to the sensor does not need to be replaced.

[0068] Also, the graph of Fig. 10(a) shows that at the date and time d2 within a predetermined number of days D1 from the current date and time d1, it is estimated that the average value of the intensity indicated by the scotopic noise data reaches the threshold value A1. Also, the graph of Fig. 10(b) shows that within a predetermined number of days D1 from the current date and time d1, it is estimated that the standard deviation of the intensity indicated by the scotopic noise data does not reach the threshold value B1. Therefore, based on these data, the degradation degree determination unit 1233 determines that the sensor corresponding to these data or the amplifier connected to the sensor will soon need to be replaced, and in that case, it is estimated that the part to be replaced is the amplifier.

[0069] The graph of Fig. 11(a) shows that at the current date and time d1, the average value of the intensity indicated by the scotopic noise data has not reached the threshold value A1. Also, the graph of Fig. 11(b) shows that at the current date and time d1, the standard deviation of the intensity indicated by the scotopic noise data has reached the threshold value B1. Therefore, based on these data, the degradation degree determination unit 1233 determines that the sensor corresponding to these data or the amplifier connected to the sensor needs to be replaced, and it is estimated that the part to be replaced is the sensor.

[0070] The degradation degree determination unit 1233 stores data indicating the results of the determination and estimation performed as described above in the storage unit 1231. FIG. 12 is a diagram illustrating the configuration of a table (hereinafter referred to as the “degradation diagnosis result table”) for storing data indicating the results of the determination and estimation performed by the degradation degree determination unit 1233. In the degradation diagnosis result table, a “device ID” column, a “right long wavelength” column, a “right short wavelength” column, a “left long wavelength” column, and a “left short wavelength” column are provided. In the “device ID” column, the identification information of the flame detector 11 is stored. The “right long wavelength” column, the “right short wavelength” column, the “left long wavelength” column, and the “left short wavelength” column are columns corresponding to the sensors 111R, 112R, 111L, and 112L, respectively. Regarding these sensors, for example, data in any of the following formats (a) to (c) is stored.

[0071] (a) “Normal”: Currently, replacement of the component is not required, and it indicates that replacement of the component will not be required within a predetermined number of days D1 from now. (b) “Replacement required (##)”: Currently, replacement of the component is required, and it indicates that replacement of the component shown in “##” (either one or both of the sensor and the amplifier) is estimated to be required. (c) “Replacement soon (##) (MM / DD)”: It is estimated that replacement of the component will be required around MM / DD, and in that case, it indicates that replacement of the component shown in “##” (either one or both of the sensor and the amplifier) is estimated to be required.

[0072] Returning to the description of the functional configuration of the disaster prevention receiving panel 12 (FIG. 8). The transmission unit 1234 is realized by a communication interface 1024 that operates under the control of the processor 1021. The transmission unit 1234 transmits the dark vision noise table and the degradation diagnosis result table to the server device 13. In addition, the transmission unit 1234 transmits, for example, periodically, data indicating the value of the “average value” column of the most recent record of the dark vision noise table (excluding the record in which data indicating that the data is abnormal is stored in the “data abnormality” column) to the flame detector 11 as steady-state correction constant data.

[0073] The display control unit 1235 is realized by the processor 1021. The display control unit 1235 performs control to cause the display 121 to display various images. For example, when receiving a flame detection signal from any one of the flame detectors 11, the display control unit 1235 generates image data representing the characters "Flame Detection Area ##", and causes the display 121 to display the image represented by the image data. Here, "Area ##" is the identification information of the monitoring area A corresponding to the right or left flame detector of the flame detector 11 that detected the flame.

[0074] The operation reception unit 1236 is realized by the input / output interface 1023 that operates under the control of the processor 1021. The operation reception unit 1236 receives operations performed by a user such as a maintenance staff on the operation unit 122. Note that the operations performed by the user on the disaster prevention receiving panel 12 using the operation unit 122 include, for example, an operation for instructing the start of the operation of the fire extinguishing device controlled by the disaster prevention receiving panel 12 at the time of flame detection.

[0075] The above is the description of the disaster prevention receiving panel 12. Since the server device 13 (see FIG. 1) is a general server device having a Web server function, the description of its hardware configuration and functional configuration is omitted.

[0076] The terminal device 14 (see FIG. 1) is a terminal device used by a maintenance staff. Since the terminal device 14 is a general terminal device having a Web browser function, the description of its hardware configuration and functional configuration is omitted.

[0077] The server device 13 receives the low-light noise table and the degradation diagnosis result table from the disaster prevention receiving panel 12, and stores the received data. Further, the server device 13 generates display instruction data (for example, HTML data) for instructing the display of a screen as shown in FIG. 13 (hereinafter referred to as "degradation diagnosis screen") in response to a request from the terminal device 14, and transmits it to the terminal device 14. The terminal device 14 displays the degradation diagnosis screen according to the display instruction data transmitted from the server device 13.

[0078] The deterioration diagnosis screen currently includes a table that displays information about the flame detector 11 that requires component replacement, and a table that displays information about the flame detector 11 that is estimated to require component replacement in the near future. By looking at the deterioration diagnosis screen, the maintenance staff can easily identify the flame detector 11 that requires maintenance work.

[0079] Also, when the maintenance staff performs a touch operation or a click operation on any row of the table on the deterioration diagnosis screen, the terminal device 14 sends a request including the identification information of the sensor corresponding to that row to the server device 13. In response to the request from the terminal device 14, the server device 13 generates display instruction data for instructing the display of a screen (hereinafter referred to as "graph display screen") including a graph related to the sensor identified by the identification information included in the request, and sends it to the terminal device 14. The graph included in the graph display screen is the graph as shown in FIG. 10 or FIG. 11. The terminal device 14 displays the graph display screen according to the display instruction data sent from the server device 13. By looking at the graph display screen, the maintenance staff can confirm the deterioration state of the flame detector 11 that requires component replacement currently or in the near future.

[0080] [Modification Example] The above-described embodiment is a specific example of the present invention, and can be variously modified within the scope of the technical idea of the present invention. Examples of such modifications are shown below. Note that two or more of the following modification examples may be appropriately combined.

[0081] (1) The stabilization period specifying unit 1164 of the flame detector 11 included in the above-described flame detection system 1 specifies the stabilization period based on the measurement results of the sensor 111 or the sensor 112. The method by which the stabilization period specifying unit 1164 specifies the stabilization period is not limited to this. For example, the flame detector 11 may be provided with a sensor (a sensor different from the sensor 111 and the sensor 112) that measures the ambient physical quantity, and the stabilization period specifying unit 1164 may specify the stabilization period based on the measurement results of that sensor.

[0082] FIG. 14 is a diagram schematically showing the hardware configuration of the flame detector 21 according to this modification. In addition to the components included in the flame detector 11 (see FIG. 2) according to the above-described embodiment, the flame detector 21 includes a sensor 117 (an example of a second sensor) connected to a computer 101. The sensor 117 is an optical camera, continuously generates an image of photographing the periphery of the flame detector 11, and outputs image data representing the generated image.

[0083] FIG. 15 is a diagram schematically showing the functional configuration of the flame detector 21. That is, when the processor 1011 of the computer 101 included in the flame detector 21 executes processing according to the program according to this modification, the flame detector 21 including a determination device indicated by reference numeral 116 in FIG. 15 is realized. The acquisition unit 1162 of the determination device 116 included in the flame detector 21 acquires the image data output from the sensor 117.

[0084] The stable period specifying unit 1164 of the determination device 116 included in the flame detector 21 compares the images represented by the image data continuously acquired by the acquisition unit 1162 between adjacent images in time series. For example, when the number of changing pixels is less than a predetermined threshold value, it is determined that there is no change between those images. Subsequently, the stable period specifying unit 1164 specifies the period during which the state where there is no change between the images has continued for a predetermined time (for example, 1 minute) or more as the stable period.

[0085] Also by the flame detector 21, the data of the stable period is taken out from the measurement value log table as dark current noise data and output to the disaster prevention receiving board 12.

[0086] Note that the type of the sensor 117 included in the flame detector 21 is not limited to an optical camera. For example, a microphone that picks up ambient sound may be adopted as the sensor 117. In this case, the stable period specifying unit 1164 specifies the period during which the state where the amplitude value of the sound measured by the sensor 117 is equal to or less than a predetermined threshold value has continued for a predetermined time or more as the stable period.

[0087] In addition, an object detection sensor for detecting moving objects in the surroundings may be adopted as sensor 117. In this case, the stabilization period specifying unit 1164 specifies, as the stabilization period, a period during which sensor 117 has continuously detected no objects for a predetermined time or longer.

[0088] Further, a vibration sensor for detecting vibration may be adopted as sensor 117. In this case, the stabilization period specifying unit 1164 specifies, as the stabilization period, a period during which the amplitude value of the vibration measured by sensor 117 has been equal to or less than a predetermined threshold value for a predetermined time or longer.

[0089] Also, sensor 117 does not necessarily have to be provided in flame detector 11. For example, sensor 117 may be a device separate from flame detector 11 that is arranged within a range of a predetermined distance from flame detector 11 and is connected to flame detector 11 wirelessly or by wire.

[0090] Also, with respect to a certain flame detector 11, sensor 111 or sensor 112 of another flame detector 11 arranged within a range of a predetermined distance from that flame detector 11 may be used as sensor 117. For example, flame detector 11(2) may acquire data indicating the amplitude value of a signal output from sensor 111 or sensor 112 of flame detector 11(1) or flame detector 11(3) installed adjacent to flame detector 11(2), and the stabilization period specifying unit 1164 of flame detector 11(2) may specify the stabilization period based on that data.

[0091] (2) The flame detector 11 included in the above-described flame detection system 1 is a two-wavelength type flame detector, but the number of wavelength bands used by the flame detector included in the flame detection system 1 for detecting flames may be 3 or more.

[0092] (3) In the above-described flame detection system 1, a part of the processing performed by the disaster prevention receiving board 12 may be performed by the flame detector 11, the server device 13, or the terminal device 14. For example, the flame detector 11 may include a degradation degree determination unit 1233. Also, in the above-described flame detection system 1, a part of the processing performed by the flame detector 11 may be performed by the disaster prevention receiving board 12, the server device 13, or the terminal device 14.

[0093] (4) Although the flame detector 11 included in the above-described flame detection system 1 monitors the space inside the tunnel TN, the area to be monitored by the flame detection system 1 is not limited to inside the tunnel. For example, the space inside a factory where there is a risk of fire may be monitored by the flame detector 11.

[0094] (5) Although the flame detector 11 included in the above-described flame detection system 1 includes a right-side flame detector and a left-side flame detector, the flame detector 11 may be a monocular flame detector that monitors only one area.

[0095] (6) In the above-described flame detection system 1, although the flame detector 11 transmits the dark vision noise data to the disaster prevention receiving panel 12 without waiting for a request from the disaster prevention receiving panel 12, the flame detector 11 may transmit the dark vision noise data to the disaster prevention receiving panel 12 in response to a request from the disaster prevention receiving panel 12.

[0096] (7) In the above-described flame detection system 1, the method for determining the degree of deterioration of the flame detector 11 described using the graphs of FIGS. 10 and 11 is an example, and various other methods may be adopted. For example, instead of the standard deviation, variance, coefficient of variation, the difference between the maximum value and the minimum value of the amplitude value, etc. may be used as an index indicating the variation of the amplitude values included in the dark vision noise data. Also, based on the shape of the graphs such as those illustrated in FIGS. 10 and 11, determination of the degree of deterioration, estimation of parts to be replaced, etc. may be performed. For example, using a large number of teacher data with the type of parts replaced in past maintenance work and the degree of deterioration of those parts as the target variables, and the dark vision noise data immediately before replacement corresponding to those parts as the explanatory variables, a learning model is generated by machine learning, and the dark vision noise data output from the flame detector 11 during operation is input into the learning model, and the learning model may output the type of parts to be replaced and the degree of deterioration of those parts.

[0097] (8) In the above-described flame detection system 1, the degree of deterioration determined by the deterioration degree determination unit 1233 is one of three levels: (a) currently, component replacement is necessary, (b) component replacement will be necessary soon, and (c) normal. The deterioration degree determination unit 1233 may determine the degree of deterioration in a different expression format. For example, the ratio of the average value of the amplitude values included in the dark vision noise data to the threshold value A1 or the ratio of the standard deviation of the amplitude values included in the dark vision noise data to the threshold value B1 may be used as the degree of deterioration of the flame detector 11.

[0098] (9) In the above-described flame detection system 1, among the components of the flame detector 11, those that may deteriorate are assumed to be the sensor and the amplifier, but the components that may deteriorate are not limited to these. For example, deterioration of wiring, contacts, etc. may also be suspected.

Explanation of Signs

[0099] 1... Flame detection system, 11... Flame detector, 12... Disaster prevention receiving board, 13... Server device, 14... Terminal device, 21... Flame detector, 101... Computer, 102... Computer, 111... Sensor, 112... Sensor, 113... Amplifier, 114... Amplifier, 115... Thermometer, 116... Determination device, 117... Sensor, 121... Display, 122... Operation unit, 123... Deterioration degree determination device, 1011... Processor, 1012... Memory, 1013... Input / output interface, 1014... Communication interface, 1021... Processor, 1022... Memory, 1023... Input / output interface, 1024... Communication interface, 1161... Storage unit, 1162... Acquisition unit, 1163... Correction unit, 1164... Stabilization period specifying unit, 1165... Flame detection unit, 1166... Transmission / reception unit, 1167... Timing unit, 1231... Storage unit, 1232... Acquisition unit, 1233... Deterioration degree determination unit, 1234... Transmission unit, 1235... Display control unit, 1236... Operation reception unit.

Claims

1. A measurement unit that measures the intensity of light by a sensor, A flame detection unit that detects a flame based on the intensity of light measured by the measurement unit, A degradation degree determination unit that calculates an index of the variation in the intensity of light measured by the measurement unit and determines the degradation degree of the measurement unit based on the index of the variation A flame detection system comprising the above.

2. The degradation degree determination unit estimates the time when the index of the variation in the intensity of light measured by the measurement unit reaches a predetermined threshold based on the change over time of the index of the variation in the past predetermined period, and determines the degradation degree of the measurement unit based on the estimated time The flame detection system according to Claim 1.

3. The degradation degree determination unit determines the degradation degree of the measurement unit based on the result of comparison between the intensity of light measured by the measurement unit and a predetermined threshold The flame detection system according to Claim 1.

4. The degradation degree determination unit estimates the time when the intensity of light measured by the measurement unit reaches a predetermined threshold based on the change over time of the intensity of light measured by the measurement unit in the past predetermined period, and determines the degradation degree of the measurement unit based on the estimated time The flame detection system according to Claim 3.

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