Abnormality determination device, abnormality determination method, and abnormality determination system

Abstract

The abnormality determination device includes: an acquisition unit that acquires a resistance value of an electric heater calculated from a voltage across both ends of an electric heater of a heater and a current flowing through the electric heater, and acquires a temperature value of the heater; a first determination unit that performs abnormality determination based on the acquired resistance value; a second determination unit that determines whether or not the acquired temperature value is in a temperature stable state within a range with respect to a first target value; and a third determination unit that determines whether or not the acquired resistance value is in a resistance stable state within a range with respect to a second target value. The first determination unit performs abnormality determination when the second determination unit determines that the temperature value is in the temperature stable state for an entire first period and the third determination unit determines that the resistance value is in the resistance stable state for an entire second period.

Description

Technical Field

[0001] This disclosure relates to an anomaly determination device, an anomaly determination method, and an anomaly determination system for determining anomalies in heaters. Background Technology

[0002] Patent Document 1 discloses an electric heater that determines the abnormality of the heater based on the magnitude of the change in the rate of increase in resistance when energized.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 8-124653 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] The resistance of the heating wire in an electric heater has temperature characteristics. The electric heater in Patent Document 1 lacks a sensor for detecting the temperature of the heating wire, and therefore sometimes cannot accurately determine the magnitude of the change in resistance rate when energized.

[0008] This disclosure provides an anomaly determination device, anomaly determination method, and anomaly determination system that can more accurately determine anomalies in heaters.

[0009] Methods for solving problems

[0010] An anomaly determination device according to one aspect of this disclosure includes: an acquisition unit that acquires a resistance value of the heating element calculated based on the voltage across the heating element of the heater and the current flowing through the heating element, and acquires a temperature value of the heater; a first determination unit that performs an anomaly determination based on the acquired resistance value to determine whether the heater is abnormal; a second determination unit that determines whether the acquired temperature value is in a temperature stable state relative to a first target value; and a third determination unit that determines whether the acquired resistance value is in a resistance stable state relative to a second target value. The first determination unit performs the anomaly determination if the second determination unit determines that the temperature is stable throughout a first period and the third determination unit determines that the resistance is stable throughout a second period.

[0011] In one aspect of the anomaly determination method of this disclosure, the resistance value of the heating element, calculated based on the voltage across the two ends of the heating element and the current flowing through the heating element, is obtained, and the temperature value of the heater is obtained. It is then determined whether the obtained temperature value is in a temperature stable state relative to a first target value, and whether the obtained resistance value is in a resistance stable state relative to a second target value. If the temperature is determined to be stable throughout the first period and the resistance is determined to be stable throughout the second period, an anomaly determination is performed to determine whether the heater is abnormal.

[0012] One aspect of the anomaly detection system disclosed herein includes a first device, a second device communicatively connected to the first device, and a third device communicatively connected to the first device.

[0013] The first device includes: a first acquisition unit that acquires a resistance value of the heating element calculated based on the voltage across the heating element of the heater and the current flowing through the heating element; and a first determination unit that performs an anomaly determination based on the acquired resistance value to determine whether the heater is malfunctioning.

[0014] The second device includes: a second acquisition unit that acquires the temperature value of the heater; and a second determination unit that determines whether the acquired temperature value is in a temperature stability state relative to a first target value.

[0015] The third device includes: a third acquisition unit that acquires the resistance value of the heating element; and a third determination unit that determines whether the acquired resistance value is in a resistance stability state relative to a second target value.

[0016] The first acquisition unit acquires the determination results of the second determination unit and the determination results of the third determination unit. If the second determination unit determines that the temperature is stable during the entire first period and the third determination unit determines that the resistance is stable during the entire second period, the first determination unit performs the abnormality determination.

[0017] Invention Effects

[0018] The anomaly determination device according to the described method can realize an anomaly determination device that can more accurately determine the anomaly of the heater.

[0019] The anomaly determination method described above can more accurately determine heater anomalies.

[0020] The anomaly determination system according to the described method is an anomaly determination system that can cope with various implementation methods and can more accurately determine the anomalies of the heater. Attached Figure Description

[0021] Figure 1 This is a block diagram illustrating an anomaly determination device according to one embodiment of the present disclosure.

[0022] Figure 2 It is used for explanation Figure 1 The diagram shows the temperature stability of the anomaly detection device.

[0023] Figure 3 It is used for explanation Figure 1 The diagram shows the resistance stability of the anomaly detection device.

[0024] Figure 4 It is used for explanation Figure 1 The first diagram shows the setting process of the second target value of the anomaly detection device.

[0025] Figure 5 It is used for explanation Figure 1 The second diagram shows the setting process of the second target value of the anomaly detection device.

[0026] Figure 6 It is used for explanation Figure 1 The flowchart of the abnormal judgment process of the abnormal judgment device.

[0027] Figure 7 It is used for explanation Figure 1 The flowchart for setting the target value of the anomaly detection device. Detailed Implementation

[0028] The following description, with reference to the accompanying drawings, illustrates an example of this disclosure. Furthermore, in the following description, terms indicating specific directions or positions (e.g., terms such as "up," "down," "right," and "left") are used as needed; however, these terms are used to facilitate understanding of this disclosure with reference to the accompanying drawings and are not intended to limit the technical scope of this disclosure by their meaning. Additionally, the following description is merely illustrative in nature and is not intended to limit this disclosure, its applications, or its uses. Moreover, the accompanying drawings are schematic, and the proportions of the dimensions may not necessarily correspond to actual dimensions.

[0029] As an example, such as Figure 1As shown, an anomaly detection device 1 according to one embodiment of this disclosure includes a CPU 2 for performing calculations, a storage unit 3, and a communication unit 4, for detecting anomalies in the heating element 10 of the heater. The storage unit 3 stores information such as programs and data required for anomaly detection of the heating element 10. The communication unit 4 performs information input and output with an external device connected wirelessly or via a wired connection. The heating element 10 is, for example, the heating wire of a resistance heater. A thermostat 11 and an SSR (Solid State Relay) 12 are connected to the heating element 10, and a power supply 13 is connected to the solid state relay 12. The thermostat 11 controls the on / off state of the solid state relay 12. When the solid state relay 12 is on, current from the power supply 13 is supplied to the heating element 10.

[0030] The anomaly determination device 1 includes an acquisition unit 100, a first determination unit 110, a second determination unit 120, a third determination unit 130, and a target value setting unit 140. The acquisition unit 100, the first determination unit 110, the second determination unit 120, the third determination unit 130, and the target value setting unit 140 each perform their functions, for example, by executing a predetermined program via the CPU 2.

[0031] The acquisition unit 100 acquires, for example, the resistance value of the heating element 10 and the temperature value of the heater via the communication unit 4. The resistance value of the heating element 10 is calculated based on the voltage across the heating element 10 and the current flowing through it. The resistance value of the heating element 10 is calculated, for example, by the CPU 2 or an external device (not shown) based on the current value detected by the current sensor 20 and the voltage value detected by the voltage sensor 30. The temperature value of the heater is detected, for example, by the temperature sensor 40. The temperature sensor 40 is, for example, located near the workpiece being heat-treated (e.g., a workpiece disposed within the housing of a heat treatment apparatus including the heater) being heated by the heating element 10.

[0032] In this embodiment, the resistance value of the obtained heating element 10 is subjected to low-pass filtering (e.g., moving average processing). The low-pass filtering of the resistance value of the heating element 10 is performed, for example, by the anomaly detection device 1 or an external device. The number of times the moving average processing of the resistance value is performed (hereinafter referred to as the number of moving averages of the resistance value) is set according to the type of heater, etc.

[0033] The first determination unit 110 performs an anomaly determination based on the resistance value obtained by the acquisition unit 100, which determines whether the heater is malfunctioning. The anomaly determination is performed, for example, by checking whether the obtained resistance value exceeds a preset threshold. If the obtained resistance value exceeds the threshold, the first determination unit 110 determines that the heater is malfunctioning.

[0034] In cases where a heater malfunction is detected, notifications may be issued indicating suspected heater degradation or failure. In such cases, multiple thresholds can be set to report heater malfunctions in stages. For example, a first threshold could be set as 103% of the resistance reference value (which is the second target value described later), and a second threshold could be set as 105% of the resistance reference value. If the obtained resistance value exceeds the first threshold, the heater degradation status is notified to be at the "Caution" level; if the obtained resistance value exceeds the second threshold, the heater degradation status is notified to be at the "Alarm" level.

[0035] If the second determination unit 120 determines that the temperature is stable throughout the specified period, and the third determination unit 130 determines that the resistance is stable throughout the specified period, the first determination unit 110 performs an anomaly determination. In this embodiment, if it is determined that the temperature is stable during the entire period obtained by multiplying the period of the acquired resistance value by the number of moving averages of the resistance value (an example of the first period), and it is determined that the resistance is stable during the entire period obtained by multiplying the period of the acquired resistance value by the number of moving averages of the resistance value (an example of the second period) (in other words, if the stability condition is met), the first determination unit 110 determines that the heater is in a stable state and performs an anomaly determination. The number of moving averages is set according to the type of heater, etc.

[0036] Figure 2 This example illustrates a situation where the determination results of the second determination unit 120 are all in a stable temperature state throughout the entire specified period. Figure 3 This example illustrates a situation where the determination results of the third determination unit 130 are all in a stable resistance state throughout the entire specified period. Figure 2 and Figure 3 In this example, the moving average of the resistance value was set to 10 times. Figure 2 In this context, C0 represents the first target temperature value, C1 represents the upper limit of the range relative to the first target value, and C2 represents the lower limit of the range relative to the first target value. Figure 3 In this context, R0 represents the second target value that serves as the reference value for resistance, R1 represents the upper limit of the amplitude relative to the second target value, and R2 represents the lower limit of the amplitude relative to the second target value.

[0037] exist Figure 2 In this context, during the entire period T0 between time T1 and time T2, all acquired temperature values ​​fall within the range relative to the first target value C0. Figure 3During the entire period T0, all the resistance values ​​obtained are within the range relative to the second target value R0. The first determination unit 110 performs anomaly determination based on the resistance values ​​obtained after time T2, but does not perform anomaly determination if any of the following conditions are met, and then obtains the determination results of the second determination unit 120 and the third determination unit 130 again.

[0038] • The determination result of the second determination unit 120 obtained during period T0 includes a determination that is not a temperature stable state, or the determination result of the third determination unit 130 obtained during period T0 includes a determination that is not a resistance stable state.

[0039] • The determination result obtained by the second determination unit 120 is that the temperature is not stable, or the determination result obtained by the third determination unit 130 is that the resistance is not stable.

[0040] The second determination unit 120 determines whether the obtained temperature value is within a stable temperature state relative to the first target value. In this embodiment, the first target value is preset, for example, based on the heater design, the location of the temperature sensor 40, and the measurement object measured by the temperature sensor 40. The range relative to the first target value is set, for example, to ±10 degrees Celsius of the first target value. The upper and lower limits of the range relative to the first target value may be included in "the range relative to the first target value" or may not be included therein.

[0041] The third determination unit 130 determines whether the obtained resistance value is in a stable resistance state within the range relative to the second target value. In this embodiment, the second target value is set by the target value setting unit 140. The range relative to the second target value is, for example, set to ±1% of the second target value. The upper and lower limits of the range relative to the second target value may be included in "the range relative to the second target value" or may not be included therein.

[0042] The target value setting unit 140 sets the resistance value at the start of setting the second target value as a temporary second target value. If it determines that all temperature values ​​obtained within a specified period are within the range relative to the first target value, and all resistance values ​​obtained within the specified period are within the range relative to the temporary second target value, it sets the temporary second target value as the second target value. For example, such as... Figure 5As shown, when the setting of the second target value starts from time T3, the target value setting unit 140 sets the resistance value R10 obtained at time T3 as a temporary second target value. In this embodiment, if it is determined that all temperature values ​​obtained within a period (an example of a third period) multiplied by the number of moving averages of the resistance values ​​obtained (the period in which the resistance values ​​are obtained) are within the range relative to the first target value, and all resistance values ​​obtained within a period (an example of a fourth period) multiplied by the number of moving averages of the resistance values ​​obtained (the period in which the resistance values ​​are obtained) are within the range relative to the temporary second target value (in other words, if the setting condition for the second target value is met), the temporary second target value is set as the second target value. The range relative to the temporary second target value is, for example, set to ±1% of the temporary second target value, similar to the second target value.

[0043] If it is not determined that all temperature values ​​obtained within the specified period are within the range of the first target value and all resistance values ​​obtained within the specified period are within the range of the temporary second target value, the target value setting unit 140 resets the last obtained resistance value as the temporary second target value.

[0044] For example, such as Figure 4 as well as Figure 5 As shown, the setting of the second target value begins at time T3, but all temperature values ​​obtained during the initial period T01 are not within the range relative to the first target value, and all resistance values ​​obtained during the initial period T01 are not within the range relative to the set temporary second target value. In this case, the target value setting unit 140 resets the resistance value R20 obtained last during the initial period T01 as the temporary second target value. Figure 4 and Figure 5 In this process, all temperature values ​​obtained during the next period T02 fall within the range relative to the first target value, and all resistance values ​​obtained during the next period T02 fall within the range relative to the resistance value R20, which is a reset temporary second target value. Therefore, the target value setting unit 140 sets the resistance value R20 as the second target value. The last obtained resistance value becomes the average value of the resistance values ​​obtained during the period. Therefore, by resetting the resistance value obtained at the end of the period as the temporary second target value, the setting process of the second target value can be shortened.

[0045] An upper limit can also be set for the number of times the target value setting unit 140 resets the temporary second target value (in other words, the number of times it determines whether the setting condition of the second target value is met). For example, if the target value setting unit 140 fails to set the second target value for a predetermined number of consecutive times (e.g., 5 times), it will not reset the temporary second target value and will stop setting the second target value.

[0046] If the obtained temperature value is in a stable temperature state and the obtained resistance value is in a stable resistance state, the target value setting unit 140 resets the second target value based on the average of the most recent (e.g., moving average) obtained resistance values. The reset of the second target value is performed, for example, each time a predetermined number of resistance values ​​(e.g., moving average of resistance values) are obtained.

[0047] Reference Figure 6 The anomaly determination process of the anomaly determination device 1 (an example of the anomaly determination method of this disclosure) will be described. Here, as an example, the following situation will be described: if it is determined that the temperature is stable throughout the first period and the resistance is stable throughout the second period, the stability condition is met, and the second target value is reset each time a resistance value is obtained. Furthermore, as an example, the following processing will be implemented by the CPU executing a prescribed program.

[0048] like Figure 6 As shown, if the acquisition unit 100 acquires the resistance value and temperature value of the heating element 10 (step S1), the first determination unit 110 determines whether the stability condition is met; in other words, it determines whether the temperature is stable throughout the first period and whether the resistance is stable throughout the second period (step S2). If the stability condition is not determined to be met, the first determination unit 110 does not perform an anomaly determination. Then, it returns to step S1 and acquires the resistance value and temperature value of the heating element 10.

[0049] If the stability condition is met, the first determination unit 110 performs an anomaly determination based on whether the obtained resistance value is greater than a threshold (step S3). If the obtained resistance value is determined to be greater than the threshold, the first determination unit 110 determines that the heater is abnormal (step S4), and the anomaly determination process ends.

[0050] If the obtained resistance value is determined to be below the threshold, the target value setting unit 140 resets the second target value (step S5). Then, it returns to step S1 and obtains the resistance value and temperature value of the heating element 10.

[0051] Reference Figure 7 The target value setting process of the anomaly detection device 1 will be explained. Here, as an example, an upper limit will be set for the number of times the setting condition for the second target value is determined. Furthermore, as an example, the following processing will be implemented by the CPU executing a prescribed program.

[0052] like Figure 7As shown, if a predetermined time has elapsed since the start of the target value setting (step S11), the acquisition unit 100 acquires the resistance value and temperature value of the heating element 10 (step S12), then the target value setting unit 140 determines whether the setting conditions for the second target value are met (step S13).

[0053] If the conditions for setting the second target value are met, the target value setting unit 140 sets the second target value (step S14), and the target value setting process ends.

[0054] If the setting condition for the second target value is determined to be invalid, the target value setting unit 140 determines whether the number of times the setting condition is determined to be invalid is a predetermined number (e.g., 5 times) or more (step S15). If the number of times the setting condition is determined to be invalid is a predetermined number or more, the target value setting unit 140 does not set the second target value, and the target value setting process ends. If the number of times the setting condition is determined to be invalid is less than the predetermined number, the process returns to step S12, and the resistance value and temperature value of the heating element 10 are obtained.

[0055] The anomaly detection device 1 can perform the following functions.

[0056] The anomaly determination device 1 includes: an acquisition unit 100 that acquires the resistance value and temperature value of the heating element 10; a first determination unit 110 that determines whether the heater is malfunctioning based on the acquired resistance value; a second determination unit 120 that determines whether the acquired temperature value is in a temperature stability state relative to a first target value; and a third determination unit 130 that determines whether the acquired resistance value is in a resistance stability state relative to a second target value. The first determination unit 110 performs an anomaly determination when the second determination unit 120 determines that the temperature is stable throughout a first period and the third determination unit 130 determines that the resistance is stable throughout a second period. With this structure, the anomaly determination device 1 can more accurately determine heater malfunctions.

[0057] The resistance value is low-pass filtered. This structure makes it easy to stabilize the resistance value.

[0058] The low-pass filtering applied to the resistance value is a moving average. This structure makes it easy to stabilize the resistance value.

[0059] The second period is obtained by multiplying the period in which the resistance value is obtained by the number of times the resistance value is moved averaged. Based on this structure, it is possible to determine more accurately whether the heater is in a state of stable resistance.

[0060] The anomaly detection device 1 includes a target value setting unit 140 for setting a second target value. The target value setting unit 140 sets the resistance value at the start of setting the second target value as a temporary second target value. If it is determined that all temperature values ​​obtained during a third period are within the range relative to the first target value, and all resistance values ​​obtained during a fourth period are within the range relative to the temporary second target value, then the temporary second target value is set as the second target value. With this structure, the second target value can be set more accurately.

[0061] If the target value setting unit 140 does not determine that all temperature values ​​obtained during the third period are within the range relative to the first target value, and all resistance values ​​obtained during the fourth period are within the range relative to the temporary second target value, it resets the last obtained resistance value as the temporary second target value. With this structure, the second target value can be set more accurately.

[0062] When the obtained temperature value is in a stable state and the obtained resistance value is in a stable state, the target value setting unit 140 resets the second target value based on the average value of the most recent obtained resistance values. With this structure, a more accurate second target value corresponding to the time-varying changes in the heater can be set.

[0063] A moving average is applied to the resistance value, and the fourth period is the period obtained by multiplying the period in which the resistance value was obtained by the number of times the resistance value has been moved. Based on this structure, the resistance value can be easily stabilized, and it is possible to more accurately determine whether the heater is in a state of resistance stability.

[0064] The anomaly detection method disclosed herein can achieve the following effects.

[0065] In the anomaly detection method, the resistance value of the heating element 10, calculated based on the voltage across the heating element 10 and the current flowing through it, is obtained, along with the temperature value of the heater. It is determined whether the obtained temperature value is within a temperature stability range relative to a first target value. It is also determined whether the obtained resistance value is within a resistance stability range relative to a second target value. If the temperature is determined to be stable throughout the first period and the resistance is determined to be stable throughout the second period, an anomaly detection is performed to determine whether the heater is abnormal. Based on this structure, heater anomalies can be detected more accurately.

[0066] The anomaly detection device 1 can also be configured as follows.

[0067] The first determination unit 110 can also be configured such that, if all four of the following conditions are met, the heater is determined to be in a stable state, and an anomaly determination is performed.

[0068] • All temperature values ​​obtained during the first period are within the range relative to the first target value (in other words, the heater is in a temperature stable state throughout the first period).

[0069] • All resistance values ​​obtained during the second period are within the range relative to the second target value (in other words, the heater is in a resistance stable state throughout the second period).

[0070] • The obtained voltage value is above the threshold.

[0071] • The obtained current value is above the threshold.

[0072] For example, if the operation command of the abnormality determination device 1 is issued when the heater is not running, or if the heater stops after the operation command of the abnormality determination device 1 is issued, the condition "the obtained voltage value is above the threshold" is met, so no abnormality determination is performed.

[0073] The first determination unit 110 may also stop the abnormal determination when it obtains a determination that the temperature is not stable or the resistance is not stable, and then obtain the determination results of the second determination unit 120 and the third determination unit 130 again.

[0074] The target value setting unit 140 can be omitted. In this case, the second target value is preset by the user, for example.

[0075] The target value setting unit 140 may also be configured to set a temporary second target value as a second target value when all four of the following conditions are met.

[0076] • All temperature values ​​obtained during the third period are within the range relative to the temporary first target value (in other words, the heater is in a temperature stable state throughout the third period).

[0077] • All resistance values ​​obtained during the fourth period are within the range relative to the temporary second target value (in other words, the heater is in a resistance stable state during the fourth period).

[0078] • The obtained voltage value is above the threshold.

[0079] • The obtained current value is above the threshold.

[0080] For example, if an operation command for the abnormality determination device 1 is issued while the heater is not operating, or if the heater stops after the operation command for the abnormality determination device 1 is issued, the setting of the second target value is suspended based on the condition that "the obtained voltage value is above the threshold". Furthermore, since the voltage may temporarily drop due to overshoot, the setting of each target value will not be immediately suspended even if the obtained voltage value is below the threshold; it will continue except if all four conditions are not met consecutively for a specified number of times.

[0081] The target value setting unit 140 may also be configured to set the resistance value when it is initially determined that it is not within the range relative to the temporary second target value (e.g., in Figure 5 (Represented by R30) is reset as a temporary second target value.

[0082] The first, second, third, and fourth periods can be periods of equal or different lengths. Any two or three of the first, second, third, and fourth periods can be periods of equal length.

[0083] The first and third periods can be of any length, as set by the user.

[0084] The second and fourth periods are not limited to periods obtained by multiplying the period in which the resistance value is obtained by the number of times the resistance value is moved averaged, but can also be periods of any length set by the user.

[0085] The resistance value obtained by the acquisition unit 100 may or may not be subject to low-pass filtering, or it may be subject to low-pass filtering other than moving average.

[0086] An anomaly detection system can be configured such that the first determination unit 110, the second determination unit 120, and the third determination unit 130 are configured in different devices such as servers. For example, the anomaly detection system includes a first device equipped with the first determination unit 110, a second device equipped with the second determination unit 120, and a third device equipped with the third determination unit 130. Acquisition units 100 are provided in the first device, the second device, and the third device. The first device and the second device are connected via wired or wireless communication, and the first device and the third device are connected via wired or wireless communication. The acquisition unit of the first device acquires the determination results of the second determination unit 120 and the third determination unit 130. With this configuration, an anomaly detection system can be implemented that can cope with various embodiments and more accurately determine heater anomalies.

[0087] The temperature sensor 40 can be disposed at any position where the second determination unit 120 can determine whether the heater is in a temperature stable state; in other words, it can be disposed at a position where the temperature of the heating element 10 can be detected directly or indirectly. That is, the object of temperature measurement by the temperature sensor 40 can be the heating element 10, the object being heat-treated, or the environment surrounding the heating element 10. For example, the value measured in the manner shown below can be used as the "temperature value of the heater".

[0088] • The temperature of the heating element 10 is directly measured using temperature sensor 40.

[0089] • The surface temperature of the heat-treated object (e.g., a semiconductor wafer) after being heated by the heating element 10 is measured using a temperature sensor 40 (e.g., a thermocouple).

[0090] • The ambient temperature around the heat-treated object after being heated by the electric heating element 10 placed in the furnace is measured using a temperature sensor 40.

[0091] The various embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. Finally, various aspects of this disclosure will be described. Furthermore, in the following description, reference numerals will be added as examples.

[0092] The first aspect of the anomaly determination device 1 disclosed herein includes: an acquisition unit 100, which acquires the resistance value of the heating element calculated based on the voltage across the heating element 10 of the heater and the current flowing through the heating element 10, and acquires the temperature value of the heater; a first determination unit 110, which performs an anomaly determination based on the acquired resistance value to determine whether the heater is abnormal; a second determination unit 120, which determines whether the acquired temperature value is in a temperature stability state relative to a first target value; and a third determination unit 130, which determines whether the acquired resistance value is in a resistance stability state relative to a second target value.

[0093] If the second determination unit 120 determines that the temperature is stable throughout the first period and the third determination unit 130 determines that the resistance is stable throughout the second period, the first determination unit 110 performs the abnormality determination.

[0094] In the anomaly determination device 1 of the second aspect of this disclosure, the resistance value is subjected to low-pass filtering.

[0095] In the third-party anomaly detection device 1 disclosed herein, the low-pass filtering process applied to the resistance value is a moving average.

[0096] In the fourth aspect of the anomaly determination device 1 disclosed herein, the second period is a period obtained by multiplying the period in which the resistance value is obtained by the number of times the resistance value is moved averaged.

[0097] The fifth aspect of the anomaly determination device 1 of this disclosure includes a target value setting unit 140 for setting the second target value. The target value setting unit 140 sets the resistance value at the start of setting the second target value as a temporary second target value. When it is determined that all the temperature values ​​obtained during the third period are within the range relative to the first target value and all the resistance values ​​obtained during the fourth period are within the range relative to the temporary second target value, the temporary second target value is set as the second target value.

[0098] In the sixth aspect of the anomaly determination device 1 of this disclosure, if it is not determined that all the temperature values ​​obtained in the third period are within the range relative to the first target value and all the resistance values ​​obtained in the fourth period are within the range relative to the temporary second target value, the target value setting unit 140 resets the last obtained resistance value to the temporary second target value.

[0099] In the anomaly determination device 1 of the seventh aspect of this disclosure, when the obtained temperature value is in the temperature stable state and the obtained resistance value is in the resistance stable state, the target value setting unit 140 resets the second target value based on the average value of the most recent obtained resistance values.

[0100] In the anomaly determination device 1 of the eighth aspect of this disclosure, a moving average is applied to the resistance value, and the fourth period is a period obtained by multiplying the period in which the resistance value is obtained by the number of times the resistance value is moved averaged.

[0101] In the ninth aspect of the anomaly determination method disclosed herein, the resistance value of the heating element 10, calculated based on the voltage across the two ends of the heating element 10 of the heater and the current flowing through the heating element 10, is obtained, and the temperature value of the heater is obtained. It is determined whether the obtained temperature value is in a temperature stable state relative to a first target value, and whether the obtained resistance value is in a resistance stable state relative to a second target value. If it is determined that the temperature is in a stable state throughout the first period and the resistance is in a stable state throughout the second period, an anomaly determination is performed to determine whether the heater is abnormal.

[0102] The anomaly detection system of the tenth method disclosed herein includes a first device, a second device communicatively connected to the first device, and a third device communicatively connected to the first device.

[0103] The first device includes: a first acquisition unit that acquires the resistance value of the heating element 10 calculated based on the voltage across the heating element 10 of the heater and the current flowing through the heating element 10; and a first determination unit 110 that performs an anomaly determination based on the acquired resistance value to determine whether the heater is malfunctioning.

[0104] The second device includes: a second acquisition unit that acquires the temperature value of the heater; and a second determination unit 120 that determines whether the acquired temperature value is in a temperature stability state relative to a first target value.

[0105] The third device includes: a third acquisition unit that acquires the resistance value of the heating element 10; and a third determination unit 130 that determines whether the acquired resistance value is in a resistance stability state relative to a second target value.

[0106] The first acquisition unit acquires the determination result of the second determination unit 120 and the determination result of the third determination unit 130. If the second determination unit 120 determines that the temperature is stable throughout the first period and the third determination unit 130 determines that the resistance is stable throughout the second period, the first determination unit 110 performs the abnormality determination.

[0107] By appropriately combining any of the above-described various embodiments or variations, the respective effects can be achieved. Furthermore, it is possible to combine embodiments with each other, or to combine different embodiments with different examples, and it is also possible to combine features from different embodiments or examples with each other.

[0108] This disclosure has been fully described with reference to the accompanying drawings and in connection with preferred embodiments; however, various modifications and variations will be apparent to those skilled in the art. It should be understood that such modifications and variations are included within the scope of this disclosure without departing from the scope of the appended technical solutions.

[0109] Industrial utilization potential

[0110] The anomaly detection device disclosed herein is not limited to electric heaters, but can be applied to heaters that have electric heating elements such as fuses, wires, and transmission lines that generate heat through resistance heating.

[0111] The anomaly detection method disclosed herein is not limited to electric heaters, but can be applied to heaters that have electric heating elements such as fuses, wires, and transmission lines that generate heat through resistance heating.

[0112] The anomaly detection system disclosed herein is not limited to electric heaters, but can be applied to heaters with electric heating elements such as fuses, wires, and transmission lines that generate heat through resistance heating.

[0113] Explanation of reference numerals in the attached figures

[0114] 1: Anomaly detection device; 2: CPU; 3: Storage unit; 4: Communication unit; 10: Heating element; 11: Temperature controller; 12: SSR; 13: Power supply; 20: Current sensor; 30: Voltage sensor; 40: Temperature sensor; 100: Acquisition unit; 110: First determination unit; 120: Second determination unit; 130: Third determination unit; 140: Target value setting unit.

Claims

1. An anomaly detection device, wherein, The anomaly detection device includes: The acquisition unit acquires the resistance value of the heating element calculated based on the voltage across the heating element of the heater and the current flowing through the heating element, and acquires the temperature value of the heater. The first determination unit performs an anomaly determination based on the obtained resistance value to determine whether the heater is abnormal. The second determination unit determines whether the obtained temperature value is in a stable temperature state relative to the first target value. as well as The third determination unit determines whether the obtained resistance value is in a stable resistance state relative to the second target value. If the second determination unit determines that the temperature is stable throughout the first period and the third determination unit determines that the resistance is stable throughout the second period, the first determination unit performs the anomaly determination.

2. The anomaly determination device according to claim 1, wherein, The resistance value is subjected to low-pass filtering.

3. The anomaly determination device according to claim 2, wherein, The low-pass filtering applied to the resistance value is a moving average.

4. The anomaly determination device according to claim 3, wherein, The second period is the period obtained by multiplying the period in which the resistance value is obtained by the number of times the resistance value is moved averaged.

5. The anomaly detection device according to any one of claims 1 to 4, wherein, The anomaly detection device includes a target value setting unit for setting the second target value. The target value setting unit sets the resistance value at the start of setting the second target value as a temporary second target value, and sets the temporary second target value as the second target value when it determines that all the temperature values ​​obtained in the third period are within the range relative to the first target value and all the resistance values ​​obtained in the fourth period are within the range relative to the temporary second target value.

6. The anomaly determination device according to claim 5, wherein, If it is not determined that all the temperature values ​​obtained during the third period are within the range relative to the first target value and all the resistance values ​​obtained during the fourth period are within the range relative to the temporary second target value, the target value setting unit resets the last obtained resistance value to the temporary second target value.

7. The anomaly determination device according to claim 5, wherein, When the obtained temperature value is the temperature stable state and the obtained resistance value is the resistance stable state, the target value setting unit resets the second target value based on the average of the most recent obtained resistance values.

8. The anomaly determination device according to claim 5, wherein, A moving average is applied to the resistance value. The fourth period is the period obtained by multiplying the period in which the resistance value is obtained by the number of times the resistance value is moved averaged.

9. An anomaly detection method, wherein, The resistance value of the heating element, calculated based on the voltage across the heating element and the current flowing through it, is obtained, as is the temperature value of the heater. Determine whether the obtained temperature value is in a stable temperature state relative to the first target value. Determine whether the obtained resistance value is in a stable resistance state relative to the second target value. If the temperature is determined to be stable throughout the first period and the resistance is determined to be stable throughout the second period, an anomaly determination is made based on the obtained resistance value to determine whether the heater is abnormal.

10. An anomaly detection system, wherein, The anomaly detection system includes a first device, a second device communicatively connected to the first device, and a third device communicatively connected to the first device. The first device includes: a first acquisition unit that acquires the resistance value of the heating element calculated based on the voltage across the heating element of the heater and the current flowing through the heating element; and a first determination unit that performs an anomaly determination based on the acquired resistance value to determine whether the heater is malfunctioning. The second device includes: a second acquisition unit that acquires the temperature value of the heater; And a second determination unit, which determines whether the obtained temperature value is in a stable temperature state within the range relative to the first target value. The third device includes: a third acquisition unit that acquires the resistance value of the heating element; and a third determination unit that determines whether the acquired resistance value is in a resistance stability state relative to a second target value. The first acquisition unit acquires the determination results of the second determination unit and the determination results of the third determination unit. If the second determination unit determines that the temperature is stable throughout the first period and the third determination unit determines that the resistance is stable throughout the second period, the first determination unit performs the abnormality determination.

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