JP2021144925A - Abnormality sign detection device - Google Patents

Abstract

To improve a determination accuracy for an abnormality level of an X-ray thickness measurement apparatus.SOLUTION: An abnormality sign detection device comprises a diagnosis unit. The diagnosis unit detects a spike of measurement information including at least one of a detection result of a tube voltage between a filament which emits electrons with power from an X-ray control power source and a target which irradiates a thickness measurement object with X rays by collision of the electrons emitted from the filament, a detection result of a tube current flowing between the filament and the target, a detection result of at least one of a detection voltage and a detection current corresponding to an intensity of the X rays passing the measurement object, a detection result of a drive voltage at a primary side of a transformer by which the power from the X-ray control power source is transformed and supplied to the filament, and a detection result of a drive current flowing to the primary side of the transformer. The diagnosis unit determines an abnormality level of an X-ray thickness measurement apparatus which calculates a thickness of the measurement object on the basis of the detection signal, on the basis of a product of a generation frequency of the spike and a magnitude of the spike.SELECTED DRAWING: Figure 2

Description

An embodiment of the present invention relates to an abnormality sign detection device.

As a kind of thickness gauge, there is an X-ray thickness measuring device for measuring the thickness of a steel sheet to be measured in various steel sheet manufacturing lines. The X-ray thickness measuring device measures the plate thickness to be measured online on an iron / non-ferrous rolling line that operates for 24 hours.

Japanese Unexamined Patent Publication No. 2010-167282

By the way, the X-ray thickness measuring device has an X-ray generator that irradiates a measurement target such as a steel plate with X-rays, but if the X-ray generator fails, the thickness of the measurement target can be measured. It becomes impossible to control and monitor the thickness of the measurement target on the production line. Therefore, before the X-ray generator breaks down, it is required to replace the X-ray generator to reduce the influence on the production line due to the failure of the X-ray generator.

The abnormality sign detection device of the embodiment includes a diagnostic unit. The diagnostic unit detects the tube voltage between the filament that emits electrons by the power from the X-ray control power supply and the target that irradiates the thickness measurement target with X-rays by the collision of the electrons emitted from the filament, and the filament and the target. The detection result of the tube current flowing between them, the detection result of at least one of the detection voltage and the detection current according to the intensity of the X-ray passing through the measurement target, the power from the X-ray control power supply is transformed and supplied to the filament. The spike of measurement information including at least one of the detection result of the drive voltage on the primary side of the transformer and the detection result of the drive current flowing on the primary side of the transformer is detected. Further, the diagnostic unit determines the abnormality level of the X-ray thickness measuring device that calculates the thickness of the measurement target based on the detection signal based on the product of the occurrence frequency of spikes and the size of the spikes.

FIG. 1 is a schematic view showing an example of the overall configuration of the X-ray thickness measurement system according to the present embodiment. FIG. 2 is a block diagram showing an example of the functional configuration of the control system of the X-ray thickness measurement system according to the present embodiment. FIG. 3 is a diagram for explaining an example of the fluctuation range setting process by the X-ray thickness measurement system according to the present embodiment. FIG. 4 is a diagram for explaining an example of outlier removal processing by the X-ray thickness measurement system according to the present embodiment. FIG. 5 is a diagram for explaining an example of skewness correction processing of the Shewhart R control chart by the X-ray thickness measurement system according to the present embodiment. FIG. 6 is a diagram showing an example of a Shewhart R control chart of a tube voltage created by the X-ray thickness measuring system according to the present embodiment. FIG. 7 is a diagram showing an example of spikes of a tube voltage TV detected by the X-ray thickness measuring system according to the present embodiment. FIG. 8 is a diagram showing an example of spikes of a tube voltage TV detected by the X-ray thickness measuring system according to the present embodiment. FIG. 9 is a diagram showing an example of the occurrence frequency of tube voltage spikes detected by the X-ray thickness measuring system according to the present embodiment. FIG. 10 is a diagram showing an example of the magnitude of the spike of the tube voltage detected by the X-ray thickness measuring system according to the present embodiment. FIG. 11 is a diagram showing an example of a calculation result of the product of the frequency and magnitude of spikes in the tube voltage by the X-ray thickness measuring system according to the present embodiment. FIG. 12 is a diagram showing an example of the cumulative sum of the occurrence frequencies of tube voltage spikes detected by the X-ray thickness measuring system according to the present embodiment. FIG. 13 is a diagram showing an example of the cumulative sum of the spike sizes of the tube voltage detected by the X-ray thickness measuring system according to the present embodiment. FIG. 14 is a diagram showing an example of the calculation result of the product of the cumulative sum of the occurrence frequencies of the spikes of the tube voltage and the cumulative sum of the magnitudes by the X-ray thickness measuring system according to the present embodiment. FIG. 15 is a diagram showing an example of an abnormality level level meter displayed by the X-ray thickness measuring system according to the present embodiment. FIG. 16 is a flowchart showing an example of a flow of calculation processing of the upper limit control limit and the lower limit control limit by the X-ray thickness measurement system according to the present embodiment. FIG. 17 is a flowchart showing an example of the flow of the abnormality level determination process of the X-ray thickness measuring device in the X-ray thickness measuring system according to the present embodiment.

Similar components are included in the following exemplary embodiments and modifications. Therefore, in the following, similar components are given a common reference numeral, and duplicate explanations are partially omitted. The portion included in the embodiment or the modification can be configured by replacing the corresponding portion of the other embodiment or the modification. Further, the configuration and position of the portion included in the embodiment and the modified example are the same as those of the other embodiments and the modified example unless otherwise specified.

FIG. 1 is a schematic view showing an example of the overall configuration of the X-ray thickness measurement system according to the present embodiment.

First, an example of the overall configuration of the X-ray thickness measurement system according to the present embodiment will be described with reference to FIG.

The X-ray thickness measuring system 10 measures the thickness of the measurement target 90 (for example, a steel plate) by the X-ray thickness measuring device 12, and predictive data 68 (see FIG. 2) necessary for diagnosing an abnormality of the X-ray thickness measuring device 12. ) Is generated and accumulated, and the abnormality of the X-ray thickness measuring device 12 is diagnosed.

As shown in FIG. 1, the X-ray thickness measuring system 10 of the present embodiment includes an X-ray thickness measuring device 12, a sign data server 14, a maintenance device 16 (an example of an abnormality sign detecting device), a network 18, and a network 18. To be equipped. The network 18 is a LAN (Local Area Network) or the like that connects the X-ray thickness measuring device 12, the predictive data server 14, and the maintenance device 16 so as to be able to transmit and receive information to each other. Further, the X-ray thickness measuring system 10 of the present embodiment can communicate with a higher-level device provided outside the X-ray thickness measuring system 10 via a network such as the Internet in accordance with a communication standard such as TCP / IP. ..

The X-ray thickness measuring device 12 irradiates the thickness measurement target 90 with X-rays, and measures the thickness of the measurement target 90 by the amount of X-rays passing through the measurement target 90. The X-ray thickness measuring device 12 includes a measuring unit 20, an X-ray control power supply 22, and a plate thickness calculation unit (control device) 24.

The measurement unit 20 irradiates the measurement target 90 with X-rays, and outputs at least one of the detection voltage and the detection current for calculating the thickness of the measurement target 90 as a detection value to the plate thickness calculation unit 24. The measuring unit 20 of the present embodiment includes a holding unit 26, a transformer 28, an X-ray generator 30, a detector 32, an output detecting unit 34, a resistor 35, a transformer 37, and a booster circuit 39a. It has 39b and.

The holding unit 26 holds the transformer 28, the X-ray generator 30, the detector 32, the output detection unit 34, the resistor 35, the transformer 37, and the booster circuits 39a and 39b.

The transformer 28 transforms (for example, boosts) the electric power output from the X-ray control power supply 22 and supplies it to the filament 38 of the X-ray generator 30, which will be described later.

The transformer 37 is a transformer that transforms (boosts) the voltage across the resistor 35.

The booster circuit 39a is a booster circuit that boosts the voltage applied to one end (the end on the filament 38 side) of the transformer 37.

The booster circuit 39b is a booster circuit that boosts the voltage applied to the other end (the end on the target 40 side) of the transformer 37.

The X-ray generator 30 generates X-rays by the electric power supplied from the X-ray control power supply 22 and irradiates the measurement target 90 with the X-rays. The X-ray generator 30 of the present embodiment has an X-ray tube 36, a filament 38, and a target 40.

The X-ray tube 36 is, for example, a closed tube that keeps the inside in a vacuum state. The X-ray tube 36 houses and holds the filament 38 and the target 40 inside. The filament 38 emits electrons to the target 40 by the electric power supplied from the X-ray control power supply 22 via the transformer 28. The target 40 irradiates the measurement target 90 with X-rays due to the collision of electrons emitted by the filament 38.

The detector 32 is arranged at a position facing the X-ray generator 30 with the measurement target 90 interposed therebetween. The detector 32 of the present embodiment outputs at least one of the detection voltage and the detection current according to the intensity of the X-rays irradiated from the X-ray generator 30 and passed through the measurement target 90 as a detection signal. Output to. The detector 32 may be, for example, an ionization chamber that outputs a detection voltage and a detection current according to the incident X-rays.

The output detection unit 34 converts the detection signal output by the detector 32 and outputs it to the plate thickness calculation unit 24. For example, the output detection unit 34 may have an AD converter or the like and output a value obtained by digitally converting the detection signal of the analog signal as a detection value for calculating the thickness of the measurement target 90.

The X-ray control power supply 22 is an example of a power supply, and supplies power to the filament 38 of the X-ray generator 30 via a transformer 28 based on a power supply control signal from the plate thickness calculation unit 24. The X-ray control power supply 22 may be connected to an external power source such as a commercial power source. Further, the X-ray control power supply 22 has a drive detection unit 42 and a tube detection unit 44.

The drive detection unit 42 detects the drive voltage and the drive current. The drive voltage is a value of the voltage on the primary side of the transformer 28, and is a value of the voltage of the electric power supplied by the X-ray control power supply 22. The drive current is the value of the current flowing through the primary side of the transformer 28, and is the value of the current of the electric power supplied by the X-ray control power supply 22. The drive detection unit 42 outputs the detected (detected) drive voltage and drive current to the plate thickness calculation unit 24.

In the present embodiment, the drive detection unit 42 acquires time data which is a time stamp at the time of detecting the drive voltage and the drive current from the RTC (Real Time Clock) of the X-ray control power supply 22 (not shown). Then, the drive detection unit 42 adds the acquired time data to the detected drive voltage and drive current, and outputs the data to the plate thickness calculation unit 24.

The tube detection unit 44 detects the tube voltage and the tube current. The tube voltage is the value of the voltage on the secondary side of the transformer 28, and is the value of the voltage between the filament 38 and the target 40. The tube current is the value of the current flowing through the secondary side of the transformer 28 via the X-ray generator 30, and is the value of the current flowing between the filament 38 and the target 40.

In the present embodiment, the tube detection unit 44 detects the voltage across the resistor 35 as the tube voltage, and detects the value of the current flowing through the resistor 35 as the tube current. Then, the tube detection unit 44 outputs the detected (detected) tube voltage and tube current to the plate thickness calculation unit 24.

In the present embodiment, the tube detection unit 44 acquires time data which is a time stamp at the time of detecting the tube voltage and the tube current from the RTC (not shown) included in the X-ray control power supply 22. Then, the tube detection unit 44 adds the acquired time data to the detected tube voltage and tube current, and outputs the acquired time data to the plate thickness calculation unit 24.

The plate thickness calculation unit 24 controls the overall control of the X-ray thickness measuring device 12. The plate thickness calculation unit 24 may be a computer used by an operator or the like who measures the thickness of the measurement target 90 by the X-ray thickness measuring device 12.

Specifically, the plate thickness calculation unit 24 calculates the thickness of the measurement target 90 based on the detection value acquired from the output detection unit 34.

Further, the plate thickness calculation unit 24 outputs a power supply control signal indicating a drive voltage corresponding to the tube voltage of the electric power supplied to the X-ray generator 30 to the X-ray control power supply 22. The plate thickness calculation unit 24 may generate a power supply control signal indicating a set drive voltage based on the tube voltage acquired from the tube detection unit 44.

Further, the plate thickness calculation unit 24 uses the detection result of the detection value output from the output detection unit 34, the detection result of the drive voltage by the drive detection unit 42, the detection result of the drive current by the drive detection unit 42, and the tube detection unit 44. The measurement information 56 (see FIG. 2) including at least one of the tube voltage detection result and the tube current detection result by the tube detection unit 44 is output to the network 18. In the present embodiment, the plate thickness calculation unit 24 sets the maximum, minimum, and average of the detection value, drive voltage, drive current, tube voltage, and tube current for each preset period (for example, 100 ms). The measurement information 56 including the value is output to the network 18. The plate thickness calculation unit 24 may output the measurement information 56 by broadcasting, for example.

In the present embodiment, the plate thickness calculation unit 24 outputs the measurement information 56 including the detection value among the detection value and the thickness of the measurement target 90 acquired from the output detection unit 34, but the detection value and the measurement target 90 The measurement information 56 including at least one of the thicknesses of the above is not limited to this. For example, the plate thickness calculation unit 24 may output the measurement information 56 including both the detected value and the thickness of the measurement target 90, or output the measurement information 56 including the thickness of the measurement target 90 instead of the detected value. You may.

Further, in the present embodiment, the plate thickness calculation unit 24 transmits the measurement information 56 including the maximum value, the minimum value, and the average value of the detected value, the drive voltage, the drive current, the tube voltage, and the tube current to the network 18. Although it is output, the network 18 provides measurement information 56 including at least the maximum and minimum values of the maximum, minimum, and average values of the detected value, drive voltage, drive current, tube voltage, and tube current, respectively. Anything that outputs to

The sign data server 14 repeatedly acquires the measurement information 56 from the plate thickness calculation unit 24 a plurality of times, and data 68 indicating a sign of abnormality of the X-ray thickness measuring device 12 generated from the plurality of measurement information 56 (hereinafter, sign data). (See Fig. 2) is memorized and accumulated. Here, the sign data 68 is the statistics of the measurement information 56 acquired from the X-ray thickness measuring device 12. Then, the predictive data server 14 outputs the measurement information 56 and the predictive data 68 in response to the request from the maintenance device 16.

The maintenance device 16 is, for example, a computer used by a maintenance person or the like who maintains the X-ray thickness measuring device 12. The maintenance device 16 diagnoses an abnormality in the X-ray thickness measuring device 12 based on the measurement information 56 and the sign data 68 acquired from the sign data server 14, and outputs the diagnosis result as an image or the like.

FIG. 2 is a block diagram showing an example of the functional configuration of the control system of the X-ray thickness measurement system according to the present embodiment.

First, an example of the functional configuration of the plate thickness calculation unit 24 included in the X-ray thickness measuring device 12 will be described with reference to FIG.

As shown in FIG. 2, the plate thickness calculation unit 24 includes a control side processing unit 46 and a control side storage unit 48.

The control side processing unit 46 controls the overall control of the X-ray thickness measuring device 12. The control-side processing unit 46 may be a hardware processor such as a CPU (Central Processing Unit) and a GPU (Graphics Processing Unit) that execute arithmetic processing and the like. The control-side processing unit 46 reads the program stored in the control-side storage unit 48, expands the read program into the control-side storage unit 48, and executes various arithmetic processes.

The control side processing unit 46 reads, for example, the measurement program 54 and functions as a reception unit 50 and a calculation unit 52. A part or all of the reception unit 50 and the calculation unit 52 may be configured by hardware such as a circuit including an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array).

The reception unit 50 receives the measurement information 56 and outputs it to the calculation unit 52. The reception unit 50 has, for example, a detection value output from the output detection unit 34, a drive voltage detected by the drive detection unit 42, a drive current detected by the drive detection unit 42, and a tube voltage detected by the tube detection unit 44. , And the tube current detected by the tube detection unit 44 is received as the measurement information 56.

When the calculation unit 52 acquires the measurement information 56 from the reception unit 50, the calculation unit 52 calculates the thickness of the measurement target 90 and controls the X-ray thickness measuring device 12 based on the measurement information 56. For example, the calculation unit 52 calculates the thickness of the measurement target 90 based on the detected value. In the present embodiment, the calculation unit 52 acquires a detection value from the output detection unit 34, and calculates the thickness of the measurement target 90 each time the detection value is acquired.

Further, in the present embodiment, the calculation unit 52 acquires time data which is a time stamp at the time of detecting the detected value from the RTC (not shown) included in the plate thickness calculation unit 24. Then, the calculation unit 52 adds the acquired time data to the acquired detection value and the calculated thickness of the measurement target 90. Further, the calculation unit 52 generates and outputs a power supply control signal instructing the drive voltage to the X-ray control power supply 22 so that the tube voltage and the tube current become preset values. Further, the calculation unit 52 outputs the measurement information 56 to the network 18 by broadcasting.

The control side storage unit 48 includes a ROM (Read Only Memory), a RAM (Random Access Memory), a main storage device such as an HDD (Hard Disk Drive), and an auxiliary storage device. The control side storage unit 48 stores the measurement program 54 executed by the control side processing unit 46, the measurement information 56 acquired for executing the measurement program 54, and the like. The measurement program 54 may be stored and provided in a computer-readable storage medium such as a CD-ROM (Compact Disc Read Only Memory) or a DVD-ROM (Digital Versatile Disc Read Only Memory), and may be provided by a network such as the Internet. May be provided via.

Next, an example of the functional configuration of the predictive data server 14 will be described with reference to FIG. As shown in FIG. 2, the predictive data server 14 has a predictive side processing unit 58 and a predictive side storage unit 60.

The predictive side processing unit 58 controls the overall control of the predictive data server 14. The sign side processing unit 58 may be a hardware processor such as a CPU and a GPU. The predictive side processing unit 58 reads the program stored in the predictive side storage unit 60, expands the read program into the predictive side storage unit 60, and executes various arithmetic processes. The sign side processing unit 58 reads, for example, the sign program 66 and functions as a sign unit 62 and a sign unit 64. A part or all of the acquisition unit 62 and the sign unit 64 may be configured by hardware such as a circuit including an ASIC or FPGA.

The acquisition unit 62 acquires the measurement information 56 from the X-ray thickness measuring device 12. The acquisition unit 62 of the present embodiment includes at least one parameter (detection result) of the drive voltage, drive current, tube voltage, tube current, and detected value flowing on the network 18, and at the time of detecting or calculating the parameter. The measurement information 56 to which the time data of the above is added is acquired a plurality of times and output to the sign unit 64.

The acquisition unit 62 of the present embodiment acquires the measurement information 56 from the X-ray thickness measuring device 12 at a cycle longer than the time required for the predictive data 68 to be generated by the predictive unit 64, which will be described later. That is, it is assumed that the cycle for acquiring the measurement information 56 by the acquisition unit 62 is longer than the time required for the precursor data 68 to be generated by the precursor unit 64. As a result, it is possible to prevent the processing load on the predictive data server 14 from being increased due to the generation of the predictive data 68 by the predictive unit 64, and the acquisition of the measurement information 56 from the X-ray thickness measuring device 12 from failing.

The sign unit 64 writes the measurement information 56 acquired by the acquisition unit 62 into the sign side storage unit 60. Then, the sign unit 64 generates the statistics of the measurement information 56 as the sign data 68. Then, the sign unit 64 writes the generated sign data 68 to the sign side storage unit 60.

Further, the sign unit 64 outputs the measurement information 56 and the sign data 68 stored in the sign side storage unit 60 in response to a request from the maintenance device 16. Further, the sign unit 64 notifies the generated sign data 68 to an external higher-level device according to a communication standard such as analog or TCP / IP.

The predictive side storage unit 60 includes a ROM, a RAM, a main storage device such as an HDD, and an auxiliary storage device. The sign side storage unit 60 stores the sign program 66 executed by the sign side processing unit 58, the sign data 68 generated by the execution of the sign program 66, and the like. The predictive program 66 may be stored and provided in a storage medium readable by a computer such as a CD-ROM or a DVD-ROM, or may be provided via a network such as the Internet.

Next, an example of the functional configuration of the maintenance device 16 will be described with reference to FIG.

As shown in FIG. 2, the maintenance device 16 includes a maintenance side processing unit 70, a maintenance side storage unit 72, and a display unit 73.

The maintenance side processing unit 70 controls the overall control of the maintenance device 16. The maintenance side processing unit 70 may be a hardware processor such as a CPU and a GPU. The maintenance-side processing unit 70 reads the program stored in the maintenance-side storage unit 72, expands the read program into the maintenance-side storage unit 72, and executes various arithmetic processes. The maintenance side processing unit 70 reads, for example, the maintenance program 76 and functions as a diagnostic unit 74. Part or all of the diagnostic unit 74 may be configured by hardware such as a circuit including an ASIC or FPGA.

The diagnosis unit 74 acquires the measurement information 56 and the predictive data 68 output by the predictive data server 14. In the present embodiment, the diagnostic unit 74 has acquired the measurement information 56 output from the predictive data server 14, but the present invention is not limited to this, and the X-ray thickness measuring device 12 (plate thickness calculation unit 24). The output measurement information 56 may be acquired.

Further, the diagnosis unit 74 diagnoses the abnormality of the X-ray thickness measuring device 12 based on the acquired measurement information 56. Specifically, the diagnosis unit 74 obtains the product of the occurrence frequency of spikes in the measurement information 56 and the magnitude of the spikes based on the measurement information 56. Next, the diagnostic unit 74 determines the abnormality level of the X-ray thickness measuring device 12 based on the obtained product. Here, the abnormality level is a level at which the X-ray thickness measuring device 12 is approaching a failure state.

Experimental results show that there are two types of spikes in measurement information 56: very large spikes that occur discretely and small spikes that occur continuously. Therefore, it is preferable to determine the abnormality level of the X-ray thickness measuring device 12 in consideration of both the frequency of occurrence of spikes in the measurement information 56 and the magnitude of the spikes.

Therefore, as described above, the diagnostic unit 74 determines the abnormality level of the X-ray thickness measuring device 12 based on the product of the spike occurrence frequency of the measurement information 56 and the size of the spikes. As a result, the detection result of both types of spikes can be obtained by X-ray thickness regardless of whether the spikes of both types, the very large spikes that occur discretely and the small spikes that occur continuously, occur in the measurement information 56. It can be reflected in the determination of the abnormality level of the measuring device 12. As a result, the accuracy of determining the abnormality level of the X-ray thickness measuring device 12 can be improved.

In the present embodiment, the diagnostic unit 74 first removes the transition period data from the acquired measurement information 56. Here, the transition period data is the measurement information 56 within the transition period in which the measurement information 56 (for example, the tube voltage) is changed. For example, the diagnostic unit 74 removes the transition period data from the initial measurement information 56 of the acquired measurement information 56. Here, the initial measurement information 56 is, for example, the measurement information 56 from the start of the X-ray thickness measuring device 12 until a preset time (for example, 1 minute and 10 minutes) elapses.

Next, as shown in the following equation (1), the diagnostic unit 74 sets the difference between the maximum value and the minimum value included in the initial measurement information 56 from which the transition period data has been removed in the fluctuation range of the measurement information 56. .. In the present embodiment, the diagnostic unit 74 sets the fluctuation range of the measurement information 56 every 100 ms. Further, the diagnostic unit 74 removes outliers from the fluctuation range of the measurement information 56. Next, the diagnosis unit 74 creates a Shewhart R control chart in a fluctuation range from which outliers have been removed, and performs distortion correction on the Shewhart R control chart.
Fluctuation range = (maximum value of measurement information 56)-(minimum value of measurement information 56) ... (1)

Then, the diagnosis unit 74 obtains the upper limit control limit UCL and the lower limit control limit LCL of the fluctuation range of the measurement information 56 based on the Shewhart R control chart with distortion correction. As a result, even if the measurement information 56 contains unnecessary data or the measurement information 56 contains distortion, the appropriate upper limit control limit UCL is used by using the Shewhart R chart with distortion correction. And the lower limit control limit LCL can be obtained to detect the spike of the measurement information 56. As a result, the accuracy of determining the abnormality level of the X-ray thickness measuring device can be improved. The diagnostic unit 74 shall obtain the upper limit control limit UCL and the lower limit control limit LCL for each fluctuation range of the drive voltage, drive current, tube voltage, tube current, and detected value included in the measurement information 56.

After that, the diagnostic unit 74 detects the measurement information 56 whose fluctuation range exceeds the upper limit control limit UCL or the lower limit control limit LCL among the measurement information 56 of the spike detection target as spikes. Here, the measurement information 56 of the spike detection target is, for example, the measurement information 56 after the elapse of a preset time after the activation of the X-ray thickness measuring device 12.

Further, the diagnostic unit 74 generates an indicator (hereinafter, referred to as a level meter) indicating an abnormality level of the X-ray thickness measuring device 12, and causes the display unit 73 to display the generated level meter. The display unit 73 displays the sign data 68 output from the sign data server 14 and various information such as a level meter.

The maintenance side storage unit 72 includes a ROM, a RAM, a main storage device such as an HDD, and an auxiliary storage device. The maintenance side storage unit 72 stores the maintenance program 76 and the like executed by the maintenance side processing unit 70. The maintenance program 76 may be stored and provided in a storage medium readable by a computer such as a CD-ROM or a DVD-ROM, or may be provided via a network such as the Internet.

Next, a specific example of the process of calculating the upper limit control limit UCL and the lower limit control limit LCL by the diagnosis unit 74 of the maintenance device 16 will be described. In the following description, an example in which the diagnostic unit 74 calculates the upper limit control limit UCL and the lower limit control limit LCL of the tube voltage TV, which is an example of the measurement information 56, will be described, but the tube current, the drive voltage, the drive current, and the detection From the values, the upper limit control limit UCL and the lower limit control limit LCL are calculated in the same manner.

First, the process of removing the transition period data from the initial tube voltage TV (an example of the initial measurement information 56) by the diagnostic unit 74 will be described.

When changing the tube voltage TV from one set value to another, it may take several seconds to stabilize the tube voltage TV detected by the tube detection unit 44. Therefore, when the set value of the tube voltage TV is changed, the diagnosis unit 74 determines the tube voltage TV (an example of the transition period data) of the transition period required for the tube voltage TV detected by the tube detection unit 44 to stabilize. , Removed from the tube voltage TV used to calculate the upper limit control limit UCL and the lower limit control limit LCL. However, if the transition period data has already been removed from the tube voltage TV acquired from the predictive data server 14, the diagnostic unit 74 does not have to perform the process of removing the transition period data from the tube voltage TV.

In this embodiment, the diagnostic unit 74 uses a local maxima to remove the transition period data from the tube voltage TV. Specifically, the diagnosis unit 74 converts the average of the tube voltage TV into an absolute gradient value, and sets a threshold value of the tube voltage TV to be determined as transition period data based on the absolute gradient value. Next, the diagnostic unit 74 extracts the tube voltage TV exceeding the set threshold value from the tube voltage TVs, and among the extracted tube voltage TVs, sets the tube voltage TVs different from the adjacent tube voltage TVs during the transition period. Remove as data. Here, the adjacent tube voltage TV is the set value of the tube voltage TV closest to the extracted tube voltage TV among the set values of the tube voltage TV that can be applied between the filament 38 and the target 40.

Alternatively, in this embodiment, the diagnostic unit 74 uses batch averaging to remove transition period data from the tube voltage TV. Specifically, there are a plurality of tube voltage TV set values (for example, 60 kV, 80 kV, 100 kV, 110 kV, 120 kV, 130 kV, and 140 kV) that can be applied between the filament 38 and the target 40, and each set value When the permissible limit is ± 1 kV, the diagnostic unit 74 calculates the average of the tube voltage TVs (for example, 200 tube voltage TVs) actually detected by the tube detection unit 44 for each set value of the tube voltage TV. do. Then, the diagnosis unit 74 removes the tube voltage TV that does not match the average of the tube voltage TV calculated for the set value of each tube voltage TV as the transition period data.

Next, an example of the process of setting the fluctuation range of the initial tube voltage TV by the diagnostic unit 74 will be described.

In the present embodiment, the diagnostic unit 74 sets the difference between the minimum value and the maximum value of the tube voltage TV for every 100 ms acquired from the predictive data server 14 in the fluctuation range of the tube voltage TV.

FIG. 3 is a diagram for explaining an example of the fluctuation range setting process by the X-ray thickness measurement system according to the present embodiment. In FIG. 3, the vertical axis represents the fluctuation range of the tube voltage TV, and the horizontal axis represents the data points that enable the detection result of the tube voltage TV for each preset period (for example, 100 ms) to be identified.

In the present embodiment, as shown in FIG. 3, the diagnostic unit 74 sets (difference) between the maximum value TVmax and the minimum value TVmin of the tube voltage TV at each data point in the fluctuation range of the tube voltage TV.

Next, an example of processing for removing outliers from the fluctuation range of the initial tube voltage TV by the diagnostic unit 74 will be described.

In the present embodiment, the diagnostic unit 74 sets an interquartile range (IQR) from the fluctuation range of the tube voltage TV from the replacement of the X-ray generator 30 to the elapse of a preset period. Use to remove outliers. Specifically, the diagnostic unit 74 is outside the 1.5 * IQR of each of the 75th percentile (third interquartile range) and the 25th percentile (first interquartile range) in the fluctuation range of the tube voltage TV. The fluctuation range of is removed as an outlier (outlier).

FIG. 4 is a diagram for explaining an example of outlier removal processing by the X-ray thickness measurement system according to the present embodiment. In FIG. 4, the vertical axis represents the fluctuation range of the tube voltage TV, and the horizontal axis represents the data points that enable the detection result of the tube voltage TV for each preset cycle to be identified.

The diagnostic unit 74 removes the fluctuation range outside the 1.5 * IQR of each of the 75th and 25th percentiles as an outlier in the fluctuation range of the tube voltage TV. As a result, as shown in FIG. 4, the fluctuation range of the tube voltage TV changes before and after the outlier is removed, and the spikes that can occur even in the normal tube voltage TV are the upper limit control limit UCL and the lower limit control limit LCL. It can be seen that it was deleted from the tube voltage TV used for the calculation of.

Further, in the present embodiment, the diagnostic unit 74 uses a trimmed mean to remove outliers from the fluctuation range of the tube voltage TV after a preset time has elapsed since the X-ray generator 30 was replaced. do. Specifically, the diagnostic unit 74 sorts the fluctuation range of the tube voltage TV in ascending order, and then removes the fluctuation range of the tube voltage TV at a preset ratio from each of the minimum value and the maximum value as an outlier. .. When the data set of the tube voltage TV acquired by the acquisition unit 62 is an unstable data set, or when the data set of the tube voltage TV has an extremely biased distribution, the diagnostic unit 74 uses the trimmed mean. Then, the outliers are removed from the fluctuation range of the tube voltage TV. This makes it possible to create a Shewhart R control chart with the desired sigma limit.

One of the two methods described above can be used to remove outliers from the fluctuation range of the tube voltage TV. The tube voltage TV until the elapse of the life cycle of the X-ray generator 30) has very small spikes, and the outliers can be removed by IQR. Therefore, the diagnostic unit 74 removes outliers by IQR from the fluctuation range of the tube voltage TV from the replacement of the X-ray generator 30 to the elapse of a preset period.

On the other hand, when the outliers are removed by IQR from the fluctuation range of the tube voltage TV in the latter half of the life cycle of the X-ray generator 30, the number of spikes increases, and the upper limit control limit UCL and the lower limit control limit LCL are calculated. When the fluctuation range of the tube voltage TV is used, the spike due to the latter half of the life cycle of the X-ray generator 30 may be taken into consideration in determining the abnormal level. Therefore, the diagnostic unit 74 uses the trimmed mean to remove outliers from the fluctuation range of the tube voltage TV after a preset period has elapsed since the X-ray generator 30 was replaced.

Next, the process of creating the Shewhart R control chart of the fluctuation range of the initial tube voltage TV by the diagnostic unit 74 will be described.

First, the diagnosis unit 74 creates a Shewhart R control chart of a fluctuation range in which outliers are removed. The Shewhart R chart is an easy-to-use and powerful tool for statistical management of measurement information 56. In addition, the Shewhart R chart is widely used and applied in the industrial field.

By the way, the Shewhart R chart is based on the assumption that the distribution of the measurement information 56 that is statistically managed is a normal distribution or a substantially normal distribution. However, the measurement information 56 is information representing the life cycle of the X-ray generator 30. Therefore, the number of noises in the measurement information 56 for a certain period (for example, the latter half of the life cycle of the X-ray generator 30) increases due to the deterioration of the X-ray generator 30. Therefore, the probability distribution of the dataset of measurement information 56 is often represented as a gamma or Weibull distribution tilted to the right.

FIG. 5 is a diagram for explaining an example of skewness correction processing of the Shewhart R control chart by the X-ray thickness measurement system according to the present embodiment. In FIG. 5, the vertical axis represents the number of detection results of the tube voltage TV, and the horizontal axis represents the fluctuation range of the tube voltage TV.

As shown in FIG. 5, the distribution of the fluctuation range of the tube voltage TV from which the outliers have been removed is a gamma distribution or Weibull in which the fluctuation range of the tube voltage TV having a value larger than the average of the fluctuation range of the tube voltage TV is large. It is represented by the distribution. Therefore, if the upper limit control limit UCL and the lower limit control limit LCL are calculated using the Shewhart R chart without correcting the skewness of the Shewhart R chart, spikes due to an abnormality in the X-ray thickness measuring device 12 are detected. Accuracy may be reduced.

Therefore, in the present embodiment, the diagnostic unit 74 corrects the skewness of the Shewhart R control chart of the tube voltage TV. This makes it possible to calculate the upper limit control limit UCL and the lower limit control limit LCL using the Shewhart R chart created based on the assumption that the measurement information 56 has a normal distribution or a substantially normal distribution. As a result, spikes due to an abnormality in the X-ray thickness measuring device 12 can be detected with higher accuracy.

Specifically, the diagnostic unit 74 calculates the upper limit control limit UCL and the lower limit control limit LCL of the Shewhart control chart with the skewness corrected using the following equations (2) and (3). In equations (2) and (3), the horizontal bar above R is the average of the fluctuation range of the tube voltage TV, T is an arbitrary value, and d _R corrects the skewness of the Shewhart control chart. It is a value (hereinafter referred to as skewness correction value), CL is the center line of the Shewhart control chart, σ _R is the standard deviation of the tube voltage TV, and K (R) is the skewness of the tube voltage TV. be.

FIG. 6 is a diagram showing an example of a Shewhart R control chart of a tube voltage created by the X-ray thickness measuring system according to the present embodiment. In FIG. 6, the vertical axis represents the fluctuation range of the tube voltage TV, and the horizontal axis represents the data points that enable the detection result of the tube voltage TV for each preset cycle to be identified.

As shown in FIG. 6, the diagnostic unit 74 calculates the upper limit control limit UCL and the lower limit control limit LCL of the Shewhart R control chart of the tube voltage TV using the above equations (2) and (3). Then, the diagnostic unit 74 detects as spikes the tube voltage TV whose fluctuation range exceeds the upper limit control limit UCL or the lower limit control limit LCL among the tube voltage TVs for which spikes are detected.

Next, a specific example of the process of determining the abnormality level of the X-ray thickness measuring device 12 by the diagnostic unit 74 will be described. In the following description, an example in which the diagnostic unit 74 determines the abnormality level of the X-ray thickness measuring device 12 based on the detection result of the tube voltage TV will be described, but the tube current, the drive voltage, the drive current, and the detection will be described. Regarding the value, the abnormality level of the X-ray thickness measuring device 12 is determined in the same manner.

7 and 8 are diagrams showing an example of spikes of the tube voltage TV detected by the X-ray thickness measuring system according to the present embodiment. In FIGS. 7 and 8, the vertical axis represents the fluctuation range of the tube voltage TV, and the horizontal axis represents the data points at which the detection result of the tube voltage TV for each preset cycle can be identified.

There are two main types of tube voltage TV spikes. One type is a type in which large spikes are generated discretely, as shown in FIG. The other type is a type in which small spikes are continuously generated, as shown in FIG. Therefore, the abnormality of the X-ray thickness measuring device 12 is represented by both large spikes that occur discretely and small spikes that occur continuously.

Therefore, the diagnostic unit 74 determines the abnormal level of the X-ray thickness measuring device 12 based on the product of the occurrence frequency of spikes of the tube voltage TV and the magnitude of the spikes (for example, the fluctuation range of the tube voltage TV). judge. As a result, the detection result of both types of spikes can be obtained by X-ray thickness regardless of whether the spikes of both types, the very large spikes that occur discretely and the small spikes that occur continuously, occur in the measurement information 56. It can be reflected in the determination of the abnormality level of the measuring device 12. As a result, the accuracy of determining the abnormality level of the X-ray thickness measuring device 12 can be improved.

FIG. 9 is a diagram showing an example of the occurrence frequency of tube voltage spikes detected by the X-ray thickness measuring system according to the present embodiment. In FIG. 9, the vertical axis represents the occurrence frequency of spikes of the tube voltage TV for each predetermined time (for example, 1 hour), and the horizontal axis represents the time when the spikes of the tube voltage TV are detected.

FIG. 10 is a diagram showing an example of the magnitude of the spike of the tube voltage detected by the X-ray thickness measuring system according to the present embodiment. In FIG. 10, the vertical axis represents the magnitude of the spike of the tube voltage TV at a predetermined time, and the horizontal axis represents the time when the spike of the tube voltage TV is detected.

The diagnostic unit 74 sets a flag (hereinafter referred to as a spike flag) for the detection result of the tube voltage TV whose fluctuation range exceeds the upper limit control limit UCL or the lower limit control limit LCL among the tube voltage TVs to be detected for spikes. ). Next, as shown in FIG. 9, the diagnostic unit 74 calculates the sum of the number of spike flags for each predetermined time as the occurrence frequency of spikes of the tube voltage TV. Further, as shown in FIG. 10, the diagnostic unit 74 calculates the detection result (for example, the fluctuation range of the tube voltage TV) of the tube voltage TV in which the spike flag is set for each predetermined time as the magnitude of the spike.

FIG. 11 is a diagram showing an example of a calculation result of the product of the frequency and magnitude of spikes in the tube voltage by the X-ray thickness measuring system according to the present embodiment. In FIG. 11, the vertical axis represents the product of the frequency and magnitude of spikes of the tube voltage TV at predetermined time intervals, and the horizontal axis represents the time when the spikes of the tube voltage TV are detected.

As shown in FIG. 11, the diagnostic unit 74 calculates the product of the frequency and magnitude of spikes of the tube voltage TV as the degree of abnormality of the spikes of the tube voltage TV at predetermined time intervals. Then, the diagnosis unit 74 sets the maximum value X among the abnormalities at predetermined time intervals to the highest abnormality level. Next, the diagnostic unit 74 classifies the degree of abnormality of the tube voltage TV at predetermined time intervals into a plurality of abnormality levels (for example, four abnormality levels) by the peak hold technique. As a result, the diagnostic unit 74 determines the abnormality level of the X-ray thickness measuring device 12 at predetermined time intervals.

For example, as shown in Table 1 below, the diagnostic unit 74 classifies spikes having an abnormality degree of the maximum value X or more into the highest abnormality level: 4. Further, as shown in Table 1 below, the diagnostic unit 74 classifies spikes having an abnormality degree of 3 × (maximum value X / 4) or more and a maximum value X or less into abnormality level: 3. Further, as shown in Table 1 below, the diagnostic unit 74 classifies spikes having an abnormality degree of 2 × (maximum value X / 4) or more and less than 3 × (maximum value X / 4) into abnormality level: 2. do. Further, as shown in Table 1 below, the diagnostic unit 74 classifies spikes having an abnormality degree of maximum value X / 4 or more and less than 2 × (maximum value X / 4) into abnormality level: 1. Further, as shown in Table 1 below, the diagnostic unit 74 classifies spikes having an abnormality degree of less than the maximum value X / 4 into an abnormality level: 0.

FIG. 12 is a diagram showing an example of the cumulative sum of the occurrence frequencies of tube voltage spikes detected by the X-ray thickness measuring system according to the present embodiment. In FIG. 12, the vertical axis represents the cumulative sum of the occurrence frequencies of the spikes of the tube voltage TV for each predetermined time, and the horizontal axis represents the time when the spikes of the tube voltage TV are detected.

FIG. 13 is a diagram showing an example of the cumulative sum of the spike sizes of the tube voltage detected by the X-ray thickness measuring system according to the present embodiment. In FIG. 13, the vertical axis represents the cumulative sum of the spike sizes of the tube voltage TV for each predetermined time, and the horizontal axis represents the time when the spike of the tube voltage TV is detected.

As shown in FIG. 12, the diagnosis unit 74 calculates the cumulative sum of the occurrence frequencies of the spikes of the tube voltage TV at predetermined time intervals. Further, as shown in FIG. 13, the diagnosis unit 74 calculates the cumulative sum of the sizes of the tube voltage TV for each predetermined time.

FIG. 14 is a diagram showing an example of the calculation result of the product of the cumulative sum of the occurrence frequencies of the spikes of the tube voltage and the cumulative sum of the magnitudes by the X-ray thickness measuring system according to the present embodiment. In FIG. 14, the vertical axis represents the product of the cumulative sum of the occurrence frequencies of the spikes of the tube voltage TV and the cumulative sum of the magnitudes at predetermined time intervals, and the horizontal axis represents the time when the spikes of the tube voltage TV are detected.

As shown in FIG. 14, the diagnostic unit 74 sets the product of the cumulative sum of the spike occurrence frequencies of the tube voltage TV and the cumulative sum of the spike sizes at predetermined time intervals as the abnormality of the spike of the tube voltage TV. Calculated as a degree. Then, the diagnosis unit 74 sets the maximum value among the calculated abnormalities to the highest abnormality level. Next, the diagnostic unit 74 classifies the degree of abnormality of the tube voltage TV into a plurality of abnormality levels (for example, four abnormality levels) by the peak hold technique.

FIG. 15 is a diagram showing an example of an abnormality level level meter displayed by the X-ray thickness measuring system according to the present embodiment.

As shown in FIG. 15, the diagnostic unit 74 causes the display unit 73 to display a level meter 1500 indicating the abnormality level of the X-ray thickness measuring device 12. For example, when the abnormality degree of the spike of the tube voltage TV is classified into four abnormality levels, the diagnosis unit 74 displays the level meter 1500 capable of displaying the four abnormality levels on the display unit 73 as shown in FIG. Let me.

FIG. 16 is a flowchart showing an example of a flow of calculation processing of the upper limit control limit and the lower limit control limit by the X-ray thickness measurement system according to the present embodiment.

The diagnostic unit 74 acquires the initial measurement information 56 from the predictive data server 14 until a preset time elapses after the start of the X-ray thickness measuring device 12 (step S1601). Next, the diagnostic unit 74 determines whether or not the acquired measurement information 56 includes the measurement information 56 within the transition period (step S1602).

When the acquired measurement information 56 includes the measurement information 56 within the transition period (step S1602: Yes), the diagnostic unit 74 removes the transition period data from the acquired measurement information 56 using the local maxima or batch average. (Step S1603). Then, the diagnosis unit 74 sets the difference between the maximum value and the minimum value of the measurement information 56 from which the transition period data has been removed within the fluctuation range of the measurement information 56 (step S1604). When the acquired measurement information 56 is the measurement information 56 outside the transition period (step S1602: No), the diagnostic unit 74 sets the difference between the maximum value and the minimum value of the acquired measurement information 56 as the fluctuation range of the measurement information 56. (Step S1604).

Next, the diagnostic unit 74 uses IQR or a trimmed mean to remove outliers from the fluctuation range of the measurement information report 56 (step S1605). Then, the diagnosis unit 74 performs distortion correction on the Shewhart R control chart in the fluctuation range from which the outliers have been removed, and based on the strain-corrected Shewhart R control chart, the upper limit of the fluctuation range of the measurement information 56. The control limit UCL and the lower limit control limit LCL are obtained (step S1606).

FIG. 17 is a flowchart showing an example of the flow of the abnormality level determination process of the X-ray thickness measuring device in the X-ray thickness measuring system according to the present embodiment.

The diagnosis unit 74 acquires the measurement information 56 after the lapse of a preset time after the activation of the X-ray thickness measuring device 12 from the predictive data server 14 (step S1701). Next, the diagnostic unit 74 determines whether or not the acquired measurement information 56 includes the measurement information 56 within the transition period (step S1702).

When it is determined that the acquired measurement information 56 includes the measurement information 56 within the transition period (step S1702: Yes), the diagnostic unit 74 uses the local maxima or batch average to transfer from the acquired measurement information 56 to the transition period. The data is removed (step S1703). Then, the difference between the maximum value and the minimum value of the measurement information 56 from which the transition period data has been removed is set in the fluctuation range of the measurement information 56 (step S1704). When the acquired measurement information 56 is the measurement information 56 outside the transition period (step S1702: No), the diagnostic unit 74 sets the difference between the maximum value and the minimum value of the acquired measurement information 56 as the fluctuation range of the measurement information 56. (Step S1704).

Next, the diagnostic unit 74 compares the fluctuation range of the measurement information 56 with the upper limit control limit UCL and the lower limit control limit LCL (step S1705), and the fluctuation range of the measurement information 56 is the upper limit control limit UCL or the lower limit control limit. It is determined whether or not the LCL has been exceeded (step S1706).

Then, the diagnostic unit 74 detects the measurement information 56 whose fluctuation range exceeds the upper limit control limit UCL or the lower limit control limit LCL as spikes among the measurement information 56 (step S1707). Further, the diagnosis unit 74 calculates the product of the occurrence frequency and the magnitude (variation range of the measurement information 56) of the spikes of the measurement information 56 at predetermined time intervals as the degree of abnormality, and determines the abnormality level corresponding to the calculated degree of abnormality. It is determined that the abnormality level of the X-ray thickness measuring device 12 is determined (step S1708). After that, the diagnostic unit 74 causes the display unit 73 to display the level meter based on the determination result of the abnormal level of the X-ray thickness measuring device 12 (step S1709).

As described above, according to the X-ray thickness measurement system according to the present embodiment, when spikes of any type, discretely generated very large spikes or continuously generated small spikes, occur in the measurement information 56. However, the detection results of both types of spikes can be reflected in the determination of the abnormality level of the X-ray thickness measuring device 12. As a result, the accuracy of determining the abnormality level of the X-ray thickness measuring device 12 can be improved.

Although embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. This novel embodiment can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. This embodiment is included in the scope and gist of the invention, and is also included in the scope of the invention described in the claims and the equivalent scope thereof.

10 X-ray thickness measurement system 12 X-ray thickness measurement device 14 Predictive data server 16 Maintenance device 20 Measurement unit 22 X-ray control power supply 24 Plate thickness calculation unit 26 Holding unit 28, 37 Transformer 30 X-ray generator 32 Detector 34 Output Detection unit 35 Resistance 36 X-ray tube 38 Filament 39a, 39b Booster circuit 40 Target 42 Drive detection unit 44 Tube detection unit 74 Diagnosis unit 90 Measurement target

Claims (5)

As a result of detecting the tube voltage between the filament that emits electrons by the power from the X-ray control power supply and the target that irradiates the object whose thickness is to be measured with X-rays by the collision of the electrons emitted from the filament, between the filament and the target. The detection result of the flowing tube current, the detection result of at least one of the detection voltage and the detection current according to the intensity of the X-ray passing through the measurement target, the power from the X-ray control power supply is transformed into the filament. A spike of measurement information including at least one of the detection result of the drive voltage on the primary side of the transformer supplied to the transformer and the detection result of the drive current flowing on the primary side of the transformer is detected. , A diagnostic unit that determines an abnormality level of an X-ray thickness measuring device that calculates the thickness of the measurement target based on the detection signal based on the product of the magnitude of the spike.
An abnormality sign detection device equipped with. The measurement information includes at least one maximum value and minimum value of the tube voltage detection result, the tube current detection result, the detection signal detection result, the drive voltage detection result, and the drive current detection result. Including
The diagnostic unit removes the transition period data, which is the measurement information within the transition period for changing the measurement information, from the measurement information, and the maximum value and the minimum value included in the measurement information from which the transition period data is removed. The difference from the value is set in the fluctuation range of the measurement information, the deviation value is removed from the fluctuation range, and the Schuhart R control chart of the fluctuation range from which the deviation value is removed is subjected to distortion correction and distortion correction. The upper limit control limit and the lower limit control limit of the fluctuation range are obtained based on the Schuhart R control chart, and the measurement information in which the fluctuation range exceeds the upper limit control limit or the lower limit control limit is used as a spike. The abnormality sign detection device according to claim 1, which detects the abnormality. The abnormality sign detection device according to claim 2, wherein the diagnostic unit removes the transition period data from the measurement information by using a local maxima or a batch average. 2. The diagnostic unit uses IQR to remove outliers from the fluctuation range from the replacement of the X-ray generator having the filament and the target until a preset period elapses. Alternatively, the abnormality sign detection device according to 3. The abnormality sign according to claim 4, wherein the diagnostic unit uses a trimmed mean to remove outliers from the fluctuation range after the preset period has elapsed since the X-ray generator was replaced. Detection device.

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