JP2020071137A - Temperature abnormality detection system, temperature abnormality detection method, and program - Google Patents

Abstract

To provide a temperature abnormality detection system that facilitates setting of a threshold of a target apparatus and can detect abnormality in the target apparatus in an early stage.SOLUTION: The temperature abnormality detection system comprises: a temperature measuring unit that measures a current temperature Tof a target apparatus 91 moment by moment; a maximum value detecting unit 141 that detects the maximum value ΔTof a temperature change rate ΔTbased on the measured temperature; a decay time calculating unit that calculates a decay time th from when the maximum value ΔTof the temperature change rate is detected until when the temperature change rate is reduced to a predetermined decay ratio with respect to the maximum value ΔT; a predicted temperature calculation unit 142 that calculates a predicted reaching temperature Tof the target apparatus 91 based on the decay time of the temperature change rate; and an abnormality determination unit 143 that determines that the target apparatus is abnormal when the calculated reaching temperature exceeds a predetermined temperature threshold Th.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a temperature abnormality detection system, a temperature abnormality detection method and a program, and more particularly to a temperature abnormality detection system, a temperature abnormality detection method and a program that detect a temperature abnormality of a target device.

  Conventionally, as this type of temperature abnormality detection system, for example, as disclosed in Japanese Patent Laid-Open No. 2010-224680, the rate of change in the temperature of the target device is calculated, and the rate of change exceeds a predetermined threshold value. It is known to determine that a temperature abnormality has occurred when the temperature rises.

JP, 2010-224680, A

  However, in the one described in Patent Document 1 (Japanese Patent Laid-Open No. 2010-224680), it is unclear whether the threshold value for the temperature change rate is appropriate, and for a user who is not familiar with the mechanism of temperature rise, the temperature abnormality There is a problem that it is difficult to set a threshold value for determining

  Therefore, an object of the present invention is to provide a temperature abnormality detection system, a temperature abnormality detection method, and a program capable of easily setting a threshold value for determining a temperature abnormality of a target device.

Therefore, the temperature abnormality detection system of this disclosure is
A temperature measurement unit that measures the current temperature of the target device moment by moment,
A maximum value detection unit that detects the maximum value of the temperature change rate based on the measured temperature,
After detecting the maximum value of the temperature change rate, a decay period calculation unit for calculating a decay period in which the temperature change rate is reduced to a predetermined damping ratio with respect to the maximum value,
Based on the decay period of the temperature change rate, a predicted temperature calculation unit for calculating the predicted ultimate temperature of the target device,
The calculated reaching temperature, an abnormality determination unit for determining that there is an abnormality when it exceeds a predetermined temperature threshold,
It is characterized by

  In the present specification, the “target device” is a device that is a target of temperature measurement, and refers to an object that may have a temperature rise during operation.

  The “predetermined damping ratio” refers to a value such as the damping ratio 1/2 or the damping ratio 1/3, for example. However, it is not limited to this. The decay period when the rate of temperature change decreases from the maximum value to the decay ratio of 1/2 is particularly called a “half-life”.

  In the temperature abnormality detection system of this disclosure, the temperature detection unit detects the current temperature of the target device moment by moment. The maximum value detection unit detects the maximum value of the temperature change rate based on the measured temperature. The decay period calculation unit detects a maximum value of the temperature change rate and then calculates a decay period in which the temperature change rate decreases to a predetermined damping ratio with respect to the maximum value. The predicted temperature calculation unit calculates a predicted ultimate temperature of the target device based on the decay period of the temperature change rate. The abnormality determination unit determines that there is an abnormality when the calculated ultimate temperature exceeds a predetermined temperature threshold. When the determination is performed in this manner, the user does not need to set the threshold value for the temperature change rate, and may set the temperature threshold value for the reached temperature. Therefore, the user can easily set the threshold value for determining the temperature abnormality of the target device.

In the temperature abnormality detection system of one embodiment, the current temperature is T _i , the decay period is th, the current rate of temperature change is ΔT _i , a predetermined coefficient is k, and the attainment temperature is T _inf. And the ultimate temperature T _inf is
T _inf = T _i + k × th × ΔT _i
It is characterized in that it is calculated by the following formula.

  In the temperature abnormality detection system of this one embodiment, the reached temperature of the target device can be accurately calculated by the above calculation formula. As a result, it is possible to accurately detect an abnormality in the target device.

In the temperature abnormality detection system of one embodiment, the numerical range of the predetermined coefficient k is
0.8 / log (m) ≦ k ≦ 1.2 / log (m)
, Where m is a real number that is the reciprocal of the damping ratio, and m> 1, and log is the natural logarithm.

  In the temperature abnormality detection system of this one embodiment, the reached temperature of the target device can be more accurately calculated by the above calculation formula. As a result, the abnormality of the target device can be detected more accurately.

  The temperature abnormality detection system according to one embodiment is characterized in that, when there are a plurality of target devices, the reached temperature is sequentially calculated for each target device, and whether or not there is an abnormality is determined for each target device. Temperature abnormality detection system.

  In the temperature abnormality detection system of this one embodiment, it is determined for each target device whether or not there is an abnormality. As a result, the abnormality of each target device can be accurately detected.

In another aspect, the temperature abnormality detection method of the present disclosure includes
A temperature abnormality detection method for detecting the temperature of a target device,
Measuring the current temperature of the target device moment by moment,
Detecting the maximum value of the temperature change rate based on the measured temperature,
After detecting the maximum value of the temperature change rate, a step of calculating a decay period in which the temperature change rate decreases to a predetermined damping ratio with respect to the maximum value,
Calculating a predicted ultimate temperature of the target device based on the decay period of the temperature change rate;
The calculated reaching temperature, the step of determining that there is an abnormality when exceeding a predetermined temperature threshold,
It is characterized by

  In the disclosed temperature abnormality detection method, the user can easily set the threshold value for determining the temperature abnormality of the target device.

  In still another aspect, the program of this disclosure is a program for causing a computer to execute the above-described temperature abnormality detection method.

  By causing a computer to execute the program of this disclosure, the above temperature abnormality detection method can be implemented.

  As is clear from the above, according to the temperature abnormality detection system and the temperature abnormality detection method of the present disclosure, it is possible to easily set the threshold value for determining the temperature abnormality of the target device. Further, the temperature abnormality detection method can be implemented by causing a computer to execute the program of this disclosure.

FIG. 1A is a diagram showing a schematic configuration of a temperature abnormality detection system according to an embodiment of the present invention. FIG. 1B shows a target device, which is a target of temperature abnormality detection, and a sensor housing, which are provided in the control panel in a state where the front door of the control panel in FIG. 1A is closed. It is a figure which shows the arrangement | positioning of typically. FIG. 2A is a diagram showing an appearance of the sensor array module mounted on the sensor housing. FIG. 2B is a diagram showing the temperature-sensitive element array of the radiation temperature sensor included in the sensor array module. It is a figure which shows the functional block structure of the said temperature abnormality detection system. It is a figure which shows the operation flow of the temperature abnormality detection which the said temperature abnormality detection system performs. It is a figure which shows the function which approximates the change of the temperature of a target apparatus over time. It is a figure which shows the change of the temperature change rate over time obtained by time-differentiating the function of FIG. It is a figure which shows as an example the change of the temperature with the passage of time at the time of abnormal operation of a certain target device. It is a figure which shows as an example the change of the temperature with the passage of time at the time of abnormal operation of another target device.

  Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

(System configuration)
FIG. 1A schematically shows a schematic configuration of a temperature abnormality detection system 1 according to an embodiment of the present invention. In this example, the temperature abnormality detection system 1 detects a temperature abnormality of the target device 91 arranged in the control panel 90, and is roughly classified into a radiation temperature arranged inside the front door 90f of the control panel 90. The sensor 97 and the abnormality determination device 100 arranged outside the control panel 90 are provided. In this example, the radiation temperature sensor 97 in the control panel 90 and the abnormality determination device 100 are communicably connected via signal cables 99 and 180. The radiation temperature sensor 97 and the abnormality determination device 100 may be wirelessly communicable.

  The control panel 90 has a general configuration, and in this example, a housing 90M having a rectangular parallelepiped outer shape, a target device 91 arranged in the housing 90M, and power to the target device 91 are supplied. The power supply unit 92 (see FIG. 3 described later) is provided. In this example, the housing 90M has a front door 90f that can be opened and closed as indicated by an arrow E in FIG. As shown in FIG. 1B (schematically showing the inside of the control panel 90 viewed from the right side with the front door 90f closed), the target device 91 is a rear wall 90r of the housing 90M. It is attached along the inner surface of.

  Examples of the target device 91 include various devices such as a DC power supply, a contactor, a controller, a motor driver, and a breaker, as well as power semiconductors, relays, heat sinks, power system wiring, terminals, etc. that form a part of the device Some are likely to rise.

  The radiation temperature sensor 97 includes a sensor housing 95M that houses the radiation temperature sensor 97.

As shown in FIG. 2A, in this example, the radiation temperature sensor 97 has a cylindrical can case 97b mounted on the sensor substrate 96 and a lens attached so as to close the tip opening of the can case 97b. 97 a and a temperature sensitive element array 97 c arranged along the sensor substrate 96 in the can case 97 b. The lens 97a collects infrared rays emitted from the target device 91 and makes them incident on the temperature-sensitive element array 97c. In this example, the temperature-sensitive element array 97c is made of a thermopile (thermoelectric stack), and as shown in FIG. 2 (B), is composed of an array of 8 rows × 8 columns of temperature-sensitive elements 191, 191, ... .. The temperature-sensing elements 191, 191, ... Look at different directions in the field of view of the radiation temperature sensor 97 through the lens 97a, so that a plurality of (64 in this example) temperatures representing the temperature distribution in the field of view can be obtained. It is possible to output a signal. As will be described later, of these 64 temperature signals, the temperature represented by the selected signal is acquired as the temperature T _i (n). In this example, n = 1-64.

As described above, when the radiation temperature sensor 97 is provided, the radiation temperature sensor 97 can measure the temperature T _i indicated by the target device 91 at a position distant from the target device 91 in the housing 90M of the control panel 90. Therefore, even if the temperature of the target device 91 rises abnormally, it is unlikely to be damaged by the temperature rise. Further, the radiation temperature sensor 97 itself has an advantage that there is less danger of short circuit, ignition, etc., as compared with, for example, a thermocouple temperature sensor.

  In this example, only one target device 91 is shown in the field of view of the radiation temperature sensor 97, but the invention is not limited to this. The field of view of the radiation temperature sensor 97 may include a plurality of target devices that may increase in temperature during operation. Further, even when the temperature of each of the plurality of parts of the target device 91 rises during operation, the radiation temperature sensor 97 can observe the temperature of each of the plurality of parts.

  As shown in FIG. 1B, the sensor substrate 96 on which the radiation temperature sensor 97 is mounted is mounted on the above-described sensor housing 95M with the lens 97a of the radiation temperature sensor 97 facing the outside. The sensor housing 95M is firmly attached to the inner surface of the front door 90f of the control panel 90 by a mounting bracket (not shown). In this example, the sensor housing 95M (and the sensor substrate 96) is attached in a state of being inclined with respect to the vertical inner surface of the front door 90f so that the target device 91 can enter the visual field of the radiation temperature sensor 97.

  In addition, in this example, the radiation temperature sensor 97 is configured to operate by power supply from a battery (not shown) mounted in the sensor housing 95M. However, the radiation temperature sensor 97 may be supplied with power from the power supply unit 92 of the control panel 90.

  FIG. 3 shows a functional block configuration of the temperature abnormality detection system 1.

  In this example, the abnormality determination device 100 included in the temperature abnormality detection system 1 includes an operation unit 103, a storage unit 102, a control unit 101, a communication unit 104, and an alarm unit 105.

  The operation unit 103 is composed of a keyboard and a mouse in this example. In this example, the operation unit 103 is used, in particular, by the user for inputting a process start / end instruction and a threshold Th for determining a temperature abnormality.

In this example, the storage unit 102 includes an EEPROM (electrically rewritable nonvolatile memory) capable of storing data non-temporarily and a RAM (random access memory) capable of storing data temporarily. Contains. The storage unit 102 stores software (computer program) for controlling the control unit 101. Further, in this example, the storage unit 102 stores the threshold Th for the temperature abnormality determination input by the user. Further, as described later, the storage unit 102 stores numerical values such as the temperature T _i , the temperature change rate ΔT _i , and the maximum value ΔT _max of the temperature change rate.

  In this example, the control unit 101 includes a processor that operates according to a control program (software) stored in the storage unit 102. The control unit 101 includes a temperature change rate calculation unit 141 configured by software, a reached temperature calculation unit 142, and a determination unit 143. The temperature change rate calculation unit 141 constitutes a temperature measurement unit and a maximum value detection unit. The reached temperature calculation unit 142 constitutes a decay period calculation unit and a predicted temperature calculation unit. The determination unit 143 constitutes an abnormality determination unit. Although the control unit 101 includes the processor in this example, the present invention is not limited to this. The control unit 101 may include a logic circuit (integrated circuit) such as a PLD (Programmable Logic Device) and an FPGA (Field Programmable Gate Array). The operation of the control unit 101 will be described later in detail using the operation flow of FIG.

  The communication unit 104 is controlled by the control unit 101 and transmits predetermined information to an external device, or receives information from the external device and passes it to the control unit 101. In this example, the communication unit 104 receives an instruction from an external device. The communication unit 104 also transmits a temperature abnormality signal AT to a host device (not shown).

  In this example, the alarm unit 105 includes a display 151 including an LCD (liquid crystal display element) and a buzzer 152. The display 151 displays various information on the display screen based on the signal from the control unit 101. The buzzer 152 emits a buzzer sound based on the signal from the control unit 101.

(Deriving the formula for calculating the ultimate temperature)
Next, the process of deriving the formula for calculating the ultimate temperature when a certain amount of heat is added to the heat capacity of the target device will be described.

When a constant amount of heat is added to the heat capacity, the transfer function can be approximated by the first-order lag characteristic. Next, the equation Eq1 representing the first-order lag characteristic is shown.
G (s) = K / (τ · s + 1) (Eq1)
However, s is a Laplace operator, K is a gain constant, and τ is a time constant.

At this time, this time response is called an indental response or a step response. The time response is obtained by the following equation Eq2. In this example, as shown in FIG. 5, the temperature indicated by the target device is approximated by a function A (t) depending on time t.
A (t) = K (1-exp (-t / τ)) (Eq2)

The change rate of the step response A (t) of the equation Eq2 is obtained by the time derivative of the equation Eq2. Next, the equation Eq3 of time differentiation is shown.
A ′ (t) = (K / τ) · exp (−t / τ) (Eq3)

The rate of change A ′ (t) becomes a ratio as in the following equation Eq4 when x has elapsed from the time t.
A '(t + x) / A' (t)
= ((K / τ) · exp (-(t + x) / τ)) / ((K / τ) · exp (-t / τ))
= Exp (-(t + x) / τ) / exp (-x / τ)
= Exp (-x / τ) (Eq4)

  Therefore, it can be seen that the rate of change A ′ (t) decreases at a constant time ratio at any time t. This means that the decay period does not change.

  Here, A (t0) and A '(t0) at a certain time t0 and the decay period th of the rate of change are measured to obtain the ultimate temperature A (t → ∞) that A (t) reaches.

  First, with A (t0) as the initial value, the convergent value (arrival temperature) T∞ of the temperature that changes from the rate of change A ′ (t0) in the constant decay period th can be calculated by the following equation Eq5.

・・・（Ｅｑ５）

... (Eq5)

  Here, by substituting the result of a = 0.5 in the following equation Eq6 into the above equation Eq5, the equation Eq7 described later can be obtained. In this example, a = 0.5 (this means the half-life), but it is not limited to this. a can take an arbitrary damping ratio. For example, if the damping ratio is ⅓, a = 0.333 ... May be substituted into the above equation Eq5.

≒１．４４・ｔｈ ・・・（Ｅｑ６）

≒ 1.44 ・ th ・ ・ ・ (Eq6)

T∞ = A (t0) −A ′ (t0) · th / log (a)
= A (t0) -A '(t0) .th / log 0.5
≈A (t0) + A '(t0) /1.44·th (Eq7)

  As described above, the reached temperature T∞ can be calculated by the equation Eq7 at the arbitrary time t0 using the temperature A (t0), the temperature change rate A ′ (t0), and the change rate decay period th.

  For example, when A (t0) = 40 ° C., decay period th = 10 minutes, and A ′ (t0) = 0.1 ° C./minute, the reached temperature T∞ = 40 ° C. + 1.44 · 10 minutes · 0.1 ° C. /Min.apprxeq.41.4.degree. C. can be calculated.

FIG. 6 shows a change in the temperature change rate with the passage of time. As can be seen from the function A ′ (t) in FIG. 6, the temperature change rate increases with time to the maximum value ΔT _max , and then decreases. The temperature change rate decay period th represents the period th from the time when the maximum value ΔT _max of the temperature change rate is reached to the time when ΔT _max / 2. In this example, the half-life ΔT _max / 2 is set, but it is not limited to this. You may calculate the time used as arbitrary damping ratios, such as (DELTA) _Tmax / 3.

(Operation of temperature abnormality detection)
FIG. 4 shows a flow of temperature abnormality detection processing (temperature abnormality detection method) executed by the abnormality determination device 100. In this example, at the same time as the operation of the control panel 90 is started, the abnormality determination device 100 receives the processing start instruction via the operation unit 103 shown in FIG. 3, and starts the temperature abnormality detection processing. In this example, as shown in FIG. 2B, the radiation temperature sensor 97 measures the temperature of the target device 91 corresponding to the detection area divided for each of the n temperature-sensitive elements 191 (temperature cells). It is detecting. In this example, the temperature cell was divided into 64, and n = 1 to 64.

First, as shown in step S1 of FIG. 4, the control unit 101 reads a threshold Th for outputting a temperature alarm. Since the temperature cell is divided into 64, the threshold values Th of n = 1 to 64 are read 64 times in total. Here, the threshold Th is stored in the storage unit 102 in advance by the user's input through the operation unit 103. The control unit 101 constantly inputs a temperature signal (temperature T _i ) for each temperature cell output by the radiation temperature sensor 97 through an input / output interface (not shown). Further, the control unit 101 stores the current temperature T _i in the storage unit 102 in a time series manner every moment.

Next, as shown in step S2 of FIG. 4, the control unit 101 operates as the temperature change rate calculation unit 141 to calculate the difference between the temperature T _i of the present turn and the temperature T _i−1 of the previous turn. Thus, the temperature change rate ΔT _i is obtained. In this example, since the processing time Δt for one turn is constant, the difference ΔT _i between the temperature T _i of this turn and the temperature T _i−1 of the previous turn is the temperature change. Perceived as a rate. The temperature change rate ΔT _i thus obtained is stored in the storage unit 102 in time series. In addition, a total of 64 temperature change rates ΔT _i are calculated for each of the n = 1 to 64 temperature cells.

Next, as shown in step S3 of FIG. 4, the control unit 101 functions as the temperature change rate calculation unit 141, and changes the temperature change rate ΔT _i−1 in the previous turn from the temperature change rate in the current turn. It is determined whether ΔT _i has not decreased. If not the temperature change rate [Delta] T _i at the current turn is reduced with respect to the temperature change rate [Delta] T _i-1 of the previous turn (NO in step S3), it is determined that the temperature change rate is increasing , And returns to step S2 to calculate the temperature change rate of the next turn. In step S3, if the decrease rate of temperature change [Delta] T _i at this turn to temperature change rate [Delta] T _i-1 at the previous turn stored in sequence (YES in step S3), the temperature change It is determined that the rate has reached the maximum value of the rate of change (here, the rate of temperature change ΔT _i−1 at the previous turn is ΔT _max ) and the process proceeds to step S4. Note that a total of 64 temperature change rate maximum values ΔT _max are obtained for each of the temperature cells of n = 1 to 64.

Next, as shown in step S4 of FIG. 4, the control unit 101 determines whether or not the current temperature change rate ΔT _i is lower than ΔT _max / 2. If the current temperature change rate ΔT _i is not smaller than ΔT _max / 2 (NO in step S4), it is determined that the temperature change rate ΔT _i is decreasing, and step S4 is repeated. If the current temperature change rate ΔT _i is smaller than ΔT _max / 2 in step S4 (YES in step S4), it is determined that the current temperature change rate ΔT _i has reached ΔT _max / 2, Proceed to S5.

Next, as shown in step S5 of FIG. 4, the control unit 101 calculates the decay period th of the temperature change rate. Specifically, the control unit 101, the count value when calculated rate of temperature change [Delta] T _i, by converting the time from [Delta] T _max to [Delta] T _max / 2, to calculate the duration of the decay period th. In this example, the half-life ΔT _max / 2 is set, but it is not limited to this. It is also possible to calculate a decay period having an arbitrary decay ratio such as ΔT _max / 3. As a result, the influence of noise on the temperature change rate ΔT _i can be reduced. As a result, the ultimate temperature can be calculated accurately. After calculating the decay period th, the process proceeds to step S6. Note that a total of 64 decay periods th are calculated for each of the n = 1 to 64 temperature cells.

Next, as shown in step S6 of FIG. 4, the control unit 101 works as the ultimate temperature calculation unit 142, sets the current temperature to T _i , the decay period to th, the current temperature change rate to ΔT _i, and When the determined coefficient is k, the ultimate temperature T _inf is calculated by the following equation Eq8.
T _inf = T _i + k × th × ΔT _i (Eq8)
Here, k is a coefficient for correcting the difference between the temperature reached by the first-order lag model (logical value) and the actual machine. Preferably, a numerical range of 0.5 ≦ k ≦ 1.5 is adopted. More preferably, 0.8 / log (m) ≦ k ≦ 1.2 / log (m), where m is a real number that is the reciprocal of the damping ratio, and m> 1, and log is the natural logarithm. The numerical range that is is adopted.

Next, as shown in step S7 of FIG. 4, the control unit 101 functions as the determination unit 143 and determines whether the reached temperature T _inf exceeds the threshold Th. When the reached temperature T _inf exceeds the threshold value Th (YES in step S7), it is determined that the target device 91 temperature abnormality has occurred. The control unit 101 creates a temperature abnormality signal AT indicating that a temperature abnormality has occurred, and outputs it to the alarm unit 105 shown in FIG. As a result, the display 151 included in the alarm unit 105 displays an alarm indicating that the temperature abnormality of the target device 91 has occurred (for example, "the temperature abnormality has occurred in the target device n") on the display screen. indicate. Further, the buzzer 152 sounds a buzzer sound as an alarm (step S9). In this example, in parallel with this, the control unit 101 outputs a temperature abnormality signal AT to an external device (not shown) via the communication unit 104.

Next, when the determination unit determines that the reached temperature T _inf does not exceed the threshold value Th (NO in step S7), the process proceeds to step S9. In this example, the reached temperature T _inf is sequentially calculated 64 times in total for each of the temperature cells of n = 1 to 64 and sequentially compared with each threshold value Th. In this case, even if at least one of the temperature cells of n = 1 to 64 exceeds the threshold value Th _inf , the target device 91 corresponding to the temperature cell exceeding the threshold value Th is designated and an alarm is output.

Next, as shown in step S9 of FIG. 4, the control unit 101 determines whether or not the end condition is satisfied. Specifically, the end condition is satisfied when the end time of the temperature detection of the target device 91 by the radiation temperature sensor 97 is determined, when the end time is exceeded, or the operation unit 103 of the user. When the end instruction is received by the instruction through. When it is determined that the ending condition is not satisfied (NO in step S9), the process returns to step S6 and the ultimate temperature T _inf is calculated. On the other hand, when it is determined that the termination condition is satisfied (YES in step S9), the process flow of the temperature abnormality detection method executed by the temperature abnormality detection system is ended.

When the determination as to whether or not the temperature abnormality has occurred is performed in this way, the user does not need to set the threshold value for the temperature change rate, but may set the temperature threshold value for the reached temperature T _inf . .. Therefore, the user can easily set the threshold Th for determining the temperature abnormality of the target device 91.

  In this example, the reached temperature of the target device 91 can be accurately calculated by the calculation formula Eq8. As a result, the abnormality of the target device 91 can be accurately detected.

  In this example, it is determined whether or not there is an abnormality for each target device 91 corresponding to the temperature cells of n = 1 to 64. As a result, when the radiant temperature sensor 97 includes a plurality of target devices 91 whose temperature may rise during operation in the visual field, the temperature abnormality of each target device 91 can be detected. Further, even when the temperature of each of the plurality of parts of the target device 91 rises during operation, the temperature abnormality of each of the plurality of parts can be detected.

  FIG. 7 exemplifies a temperature change with the lapse of time at the time of abnormal operation of a certain target device (this is 91A). In this example, the threshold value Th is set to 100 ° C. The temperature of the target device 91A is indicated by a graph Ca that increases with time. In this example, it is found at time ta that the predicted arrival temperature of the target device 91A exceeds the threshold Th = 100 ° C. Therefore, an alarm is output at time ta. As a result, the temperature abnormality of the target device 91A can be detected earlier than the time tar at which the temperature actually exceeds the threshold Th = 100 ° C.

  FIG. 8 illustrates a temperature change with the passage of time during abnormal operation of another target device (this is 91B). In this example, the threshold value Th is set to 100 ° C. As in the case of FIG. 7, the temperature of the target device 91B is shown by a graph Cb that rises with time. However, as compared with the graph Ca of FIG. 7, the graph Cb of FIG. 8 gradually rises with the passage of time. In this example, it is found at time tb that the predicted reached temperature of the target device 91 exceeds the threshold Th = 100 ° C. Therefore, an alarm is output at time tb. Accordingly, the temperature abnormality of the target device 91B can be detected earlier than the time tbr at which the temperature actually exceeds the threshold Th = 100 ° C. Further, in the example of FIG. 8, the time tb at which the alarm is output is much earlier than the time tbr at which the temperature actually exceeds the threshold Th = 100 ° C., as compared with the example of FIG. 7. Such early warning is useful for the user.

  In addition, the above-described temperature abnormality detection method is a recording medium capable of storing data as software (computer program) such as CD (compact disc), DVD (digital versatile disc), and flash memory in a non-transitory manner. It may be recorded in. By installing the software recorded in such a recording medium in a substantial computer device such as a personal computer, a PDA (Personal Digital Assistants), a smartphone, a PLC (Programmable Logic Controller), etc. The temperature abnormality detection method described above can be executed.

  Further, in the above example, the abnormality determination device 100 is arranged outside the control panel 90, but the invention is not limited to this. For example, the abnormality determination device 100 may be incorporated in the sensor housing 95M provided inside the control panel 90. In that case, it is preferable that the abnormality determination device 100 be provided with a communication unit capable of wireless communication and that when the temperature abnormality of the target device 91 occurs, the communication unit transmits an alarm to the outside. By receiving the alarm, the user can immediately recognize that the temperature abnormality has occurred in the target device 91 arranged in the control panel 90, and promptly take necessary measures such as replacing the target device 91. You can

  The above embodiments are mere examples, and various modifications can be made without departing from the scope of the present invention. The above-described plurality of embodiments can be independently established, but the embodiments can be combined with each other. Further, although various features in different embodiments can be established independently, it is also possible to combine features in different embodiments.

1 Temperature Abnormality Detection System 90 Control Panel 91 Target Equipment 97 Radiation Temperature Sensor 100 Abnormality Judgment Device 101 Control Unit 105 Alarm Unit 141 Temperature Change Rate Calculation Unit 142 Achieved Temperature Calculation Unit

Claims (6)

A temperature measurement unit that measures the current temperature of the target device moment by moment,
A maximum value detection unit that detects the maximum value of the temperature change rate based on the measured temperature,
After detecting the maximum value of the temperature change rate, a decay period calculation unit for calculating a decay period in which the temperature change rate is reduced to a predetermined damping ratio with respect to the maximum value,
Based on the decay period of the temperature change rate, a predicted temperature calculation unit for calculating the predicted ultimate temperature of the target device,
The calculated reaching temperature, an abnormality determination unit for determining that there is an abnormality when it exceeds a predetermined temperature threshold,
A temperature abnormality detection system characterized in that The temperature abnormality detection system according to claim 1,
When the current temperature is T _i , the decay period is th, the current temperature change rate is ΔT _i , a predetermined coefficient is k, and the ultimate temperature is T _inf , the ultimate temperature T _inf is ,
T _inf = T _i + k × th × ΔT _i
A temperature abnormality detection system, which is calculated by the following formula. The temperature abnormality detection system according to claim 2,
When a real number is m, the predetermined numerical range of the coefficient k is
0.8 / log (m) ≦ k ≦ 1.2 / log (m)
Where m is a real number that is the reciprocal of the damping ratio and m> 1, and log is a natural logarithm. The temperature abnormality detection system according to any one of claims 1 to 3,
A temperature abnormality detection system, wherein when there are a plurality of the target devices, the reached temperature is sequentially calculated for each target device, and whether or not there is an abnormality is determined for each of the target devices. A temperature abnormality detection method for detecting the temperature of a target device,
Measuring the current temperature of the target device moment by moment,
Detecting the maximum value of the temperature change rate based on the measured temperature,
After detecting the maximum value of the temperature change rate, a step of calculating a decay period in which the temperature change rate decreases to a predetermined damping ratio with respect to the maximum value,
Calculating a predicted ultimate temperature of the target device based on the decay period of the temperature change rate;
The calculated reaching temperature, the step of determining that there is an abnormality when exceeding a predetermined temperature threshold,
A temperature abnormality detection method characterized by the above.   A program for causing a computer to execute the temperature abnormality detection method according to claim 5.

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