TWI659286B - Degradation diagnosis device - Google Patents

Abstract

The deterioration diagnosis device of the present invention can more easily and quickly determine an abnormality of a heater.

The current measurement unit (103) measures the current supplied to the heater (111), and the control value acquisition unit (102) acquires a control value output by the control unit (113) for controlling the heater (111). The graph display control unit (106) displays a graph on the display unit (108). The graph is configured by arranging a point determined by the paired control value and measurement value selected by the selection unit (105) at the control value. And the measured value is formed on a two-dimensional plane coordinate of the axis. In addition, the range display control unit (107) superimposes the allowable range stored in the reference storage unit (101) on the graph displayed on the display unit (108) and displays it.

Description

   Degradation diagnosis device   

The present invention relates to a deterioration diagnosis device that diagnoses deterioration of a heating device including a heater.

In industrial processes, there are a large number of processes for heating materials. In such a heating process, an electric heater (heater) is generally used. In addition, in the operation control of the electric heater, a temperature regulator is used. The temperature controller uses a temperature sensor such as a thermocouple or a temperature measuring resistor to measure the temperature of a processing object (monitoring object) heated by a heater. The measured temperature is displayed numerically in a temperature controller.

In addition, in a temperature controller, a control output (MV value) is obtained based on the detected temperature (PV value) and the set temperature (SP value). The obtained control output is output to a heater operator such as a power regulator. The heater operator controls a driving current of 100 V from a commercial power source based on the control output, and outputs the driving current to the heater. The temperature of the processing object is controlled by the heating of the heater thus controlled. In addition, the temperature controller has an abnormality detection function, detects abnormal temperature of a processing object as a monitoring object, an abnormality of a temperature sensor, and the like, and outputs the detected abnormality to the outside as event information to perform an alarm (warning) display. For example, an alarm is displayed on a display that displays the temperature numerically.

In addition, the temperature regulator detects abnormalities of the heater itself such as a disconnection of the heater (see Patent Documents 1 and 2). For example, the current / voltage applied to the heater is measured to obtain the effective value power, the resistance value is further obtained based on the relationship between the current and the voltage, and the change is determined based on the change in the resistance value and the degree of change. Deterioration of the heater (see Patent Document 1). In addition, the deterioration of the heater is determined using data obtained by tabulating the actual measurement measurement points of the control output and the current value (see Patent Document 2).

Prior art literature

Patent literature

Patent Document 1: Japanese Patent No. 2685851

Patent Document 2: Japanese Patent No. 3898942

However, in the above technique, first, it is necessary to measure the current flowing to the heater and the voltage applied to the heater. In addition, in the above-mentioned technique, calculation of parameters for abnormality diagnosis such as resistance value is complicated. In addition, in the above-mentioned technology, in order to investigate the time change of the resistance value, there is a problem that measurement of elapsed time or the like requires time. In this way, in the above-mentioned technique, complicated calculation and measurement are required until the abnormality is judged.

The present invention has been made in order to solve the above-mentioned problems, and an object thereof is to make it easier and faster to determine an abnormality of a heater.

The degradation diagnosis apparatus of the present invention includes a first storage unit that stores an allowable range for determining deterioration of a heating device as a deterioration diagnosis object, and the allowable range is based on an upper allowable value of a current value with respect to a control value on a reference line. And the lower allowable value, the reference line indicates the characteristics of the heater constituting the heating device at normal time; a control value acquisition section configured to acquire a control value for controlling the heater; a current measurement section configured to measure The measurement value is acquired in accordance with the current supplied to the heater according to the control value acquired by the control value acquisition section. The second storage section stores the control value acquired by the control value acquisition section and the measurement value measured by the current measurement section in time series. The selection unit is configured to select a pair of control values and measured values corresponding to the received selection instruction from the second storage unit. The first display control unit is configured to display a graph on the display unit. In the graph, the points determined by the paired control value and measurement value selected by the selection unit are arranged on the axis of the control value and the measurement value. From a two-dimensional coordinate plane; and a second display control unit, which is configured to be stored in the first storage section of the allowable range is superimposed on the graph displayed on the display unit performs display.

In the deterioration diagnosis device described above, the first storage section stores a reference line, and the second display control section is configured to display the reference line superimposed on a graph displayed on the display section.

The above-mentioned deterioration diagnosis device includes: a deviation calculation unit configured to obtain deviations of the paired control value and measurement value from the reference line selected by the selection unit; and a third display control unit configured to determine the deviation from the deviation. The points of the deviation calculated by the calculation unit are arranged on a two-dimensional plane coordinate with time and the deviation as axes, and are displayed on the display unit together with the allowable range stored in the first storage unit.

The above-mentioned deterioration diagnosis device includes a deviation calculation unit configured to obtain a deviation of the paired control value and measurement value from the reference line selected by the selection unit, and the first display control unit selects the selected value by the selection unit. The points determined by the paired control value and measurement value are drawn as points having a shape corresponding to the magnitude of the deviation obtained by the deviation calculation unit, and the display is displayed on the display unit to arrange the point at the control value. And a graph on a two-dimensional plane coordinate of the measured value of the axis.

In the above-mentioned deterioration diagnosis device, the reference line may be a reference line obtained by approximating the characteristics of the heater, and the heater characteristic indicates a relationship between a control value of the heater in a normal state and a corresponding current.

Based on the above description, according to the present invention, it is possible to obtain an excellent effect that the abnormality of the heater can be determined more simply and quickly.

100‧‧‧Deterioration diagnosis device

101‧‧‧Reference storage section (first storage section)

102‧‧‧Control value acquisition department

103‧‧‧Current Measurement Department

104‧‧‧Measurement storage section (second storage section)

105‧‧‧Selection Department

106‧‧‧ Graph display control unit (first display control unit)

107‧‧‧Range display control unit (second display control unit)

108‧‧‧Display

111‧‧‧ heater

112‧‧‧Operation Department

113‧‧‧Control Department

114‧‧‧Temperature Measurement Department

FIG. 1 is a configuration diagram showing a configuration of a degradation diagnosis apparatus 100 according to Embodiment 1 of the present invention.

FIG. 2 is an explanatory diagram illustrating a display example of the graph display control unit 106.

FIG. 3 is a configuration diagram showing a configuration of a degradation diagnosis apparatus 100a in Embodiment 2 of the present invention.

FIG. 4 is an explanatory diagram showing a display example of the deviation display control unit 302.

FIG. 5 is an explanatory diagram illustrating another display example of the graph display control unit 106.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Embodiment 1]

First, a first embodiment of the present invention will be described using FIG. 1. FIG. 1 is a configuration diagram showing a configuration of a degradation diagnosis apparatus 100 according to Embodiment 1 of the present invention. The degradation diagnosis device 100 includes a reference storage unit (first storage unit) 101, a control value acquisition unit 102, a current measurement unit 103, a measurement storage unit (second storage unit) 104, a selection unit 105, and a graph display control unit ( The first display control unit 106), the range display control unit (second display control unit) 107, and the display unit 108. The deterioration diagnosis device 100 can perform deterioration diagnosis by a user of a heating device including the heater 111 and the operation unit 112. The deterioration diagnosis device 100 is a device that assists the deterioration determination of the heating device by a user.

The reference storage section 101 stores an allowable range (normal range) for the deterioration diagnosis of the heater 111 and the operation section 112. The allowable range is set based on the upper allowable value and the lower allowable value of the current value supplied to the heater 111 in accordance with the control value given to the operating section 112 (heating device) during normal operation. The allowable range is used by the user to determine the deterioration of the heater 111 and the operation unit 112 (heating device). Here, the larger the control value, the better the allowable range is set. In general, the smaller the control value, the smaller the desirable range of the current value becomes. Therefore, in the range where the control value is small, the width determined as abnormal is also set to be narrow, and in the range where the control value is large, the width determined as abnormal is also set to be wide.

For example, a heater characteristic is used to create a reference line, and the heater characteristic indicates a relationship between a continuously changing control value given to the heater 111 and a change in the current in the heater 111 in a normal state corresponding to the control value. The heater characteristic itself may be used as a reference line. In addition, a broken line approximation of the heater characteristics may be used as a reference line. In addition, a reference line can also be created by a polyline approximation based on a discretely changed control value and a discretely changed current value in the heater 111 in the normal state corresponding to the control value.

The allowable range may be set based on the upper allowable value and the lower allowable value of the current value with respect to the control value on the reference line. The upper allowable value line obtained based on the upper allowable value of the current value relative to the control value on the reference line and the lower allowable value line obtained based on the lower allowable value of the current value relative to the control value on the reference line. The range of time is a normal allowable range in which the heater 111 or the operation section 112 can be regarded as normal. The reference storage unit 101 may store a reference line for setting the allowable range.

The control value acquisition unit 102 acquires a control value output by the control unit 113 for controlling the heater 111 (heating device). Based on the measurement value measured by the temperature measurement unit 114 and the set value, the control unit 113 calculates the control value and outputs the control value to the operation unit 112. The control unit 113 is, for example, a temperature regulator. The operation unit 112 is configured by, for example, a known power regulator. The operation unit 112 controls a heating operation of the heater 111 by controlling a driving current of 100 V obtained from a commercial power source based on the control value. The value of the current flowing through the heater 111 is determined by this control. The control value acquisition unit 102 is a functional unit that acquires the above-mentioned control value output from the control unit 113 (see Patent Document 1).

The current measurement unit 103 measures a current supplied to the heater 111. For example, the current measurement unit 103 acquires an effective current value as a measurement value. The current measurement unit 103 is configured by a known current transformer, for example. In the embodiment, the current measurement section 103 is used as an alarm output in the control section 113 of the temperature regulator. In this case, the current measurement unit 103 detects the driving current value flowing to the heater 111 and outputs it to the control unit 113. The control unit 113 compares the detected value with a preset alarm level. When the detected value exceeds the alarm level, An alarm signal indicating abnormal heating temperature is output. The measured value may be an average current value.

The measurement storage unit 104 stores a pair of the control value acquired by the control value acquisition unit 102 and the measurement value measured by the current measurement unit 103 in a time series. In other words, the measurement storage unit 104 stores the measurement values measured in time series at predetermined intervals in association with the control values when measuring the measurement values. For example, when the current value is measured at 5 minute intervals, a pair of the control value and the measured value is stored in the measurement storage unit 104 at 5 minute intervals. In addition, a pair of an average value of the control value and an average value of the measurement values measured at a 5-minute interval for one day is stored in the measurement storage unit 104 every day. In addition, the measurement storage unit 104 stores the pair of the control value and the measurement value in association with the information of the date of measurement.

The selection unit 105 selects a pair of control values and measurement values corresponding to the received selection instruction from the measurement storage unit 104. For example, when a period is accepted as a selection instruction, a pair of a control value and a measurement value associated with the date information of the indicated period is selected.

The graph display control unit 106 displays a graph on the display unit 108 by arranging the points determined by the paired control value and the measurement value selected by the selection unit 105 on the axis of the control value and the measurement value. Coordinated on a two-dimensional plane. The range display control unit 107 displays the allowable range stored in the reference storage unit 101 on the graph displayed on the display unit 108.

For example, as shown in FIG. 2, the graph display control unit 106 displays a graph based on the selected control value and the measured value point 201 on a two-dimensional plane coordinate. In addition, the graph display control unit 106 displays the point 201 in the order of the date from the past to the present based on the date information of the alignment between the control value and the measurement value. For example, in FIG. 2, the pair of the average value of the control value and the average value of the measurement value per day is displayed for 8 days.

In addition, the range display control unit 107 displays the allowable range composed of the lower allowable value line 211 and the upper allowable value line 212 on a graph based on the point 201. When the reference storage unit 101 stores the reference line, the range display control unit 107 displays the reference line 213 together with the allowable range.

In the display of the graph described above, since the latest point 201a in the display exceeds the lower allowable value line 211 of the allowable range, it can be determined that deterioration has occurred. In addition, although the point marked with "7" is within the allowable range, the deviation from the reference line 213 is large. Since it can be judged that deterioration has progressed to some extent since this state, it can be judged that a preventive maintenance process is needed.

As described above, according to the first embodiment, it is possible to more easily and quickly determine the abnormality of the heater.

[Embodiment 2]

Next, a second embodiment of the present invention will be described using FIG. 3. FIG. 3 is a configuration diagram showing a configuration of a degradation diagnosis apparatus 100a in Embodiment 2 of the present invention. The degradation diagnosis device 100a includes a reference storage unit (first storage unit) 101, a control value acquisition unit 102, a current measurement unit 103, a measurement storage unit 104, a selection unit 105, and a graph display control unit (first display control unit). 106. A range display control unit (second display control unit) 107 and a display unit 108. These structures are the same as those of the first embodiment.

In the second embodiment, a deviation calculation unit 301 and a deviation display control unit (third display control unit) 302 are newly provided.

The deviation calculation unit 301 obtains deviations of the paired control value and measurement value selected by the selection unit 105 from the reference line.

The deviation display control unit 302 arranges the points of the deviation calculated by the deviation calculation unit 301 on a two-dimensional plane coordinate with time and the deviation as the axis, and displays the points on the display unit 108 together with the allowable range stored in the reference storage unit 101. For example, as shown in FIG. 4, the deviation display control unit 302 displays a graph based on the point 401 of the deviation of the selected measurement value on a two-dimensional plane coordinate displayed on the display unit 108. In this example, the horizontal axis is the date.

In addition, the deviation display control unit 302 superimposes and displays the allowable range composed of the lower allowable value line 411 and the upper allowable value line 412 on a graph based on the point 401.

In the display of the graph described above, since the point 401a on the latest eighth day in the display exceeds the lower allowable value line 411 of the allowable range, it can be determined that deterioration has occurred. In addition, although the point on the seventh day is within the allowable range, the deviation is large. Since it can be judged that deterioration has progressed to some extent since this state, it can be judged that a preventive maintenance process is needed.

In addition, in the configuration of the second embodiment, it is also possible to display on the display unit 108 using another graph as shown in FIG. 5. Although FIG. 5 is the same as FIG. 2, the points of the selected control value and the measured value are arranged on a two-dimensional plane coordinate with the control value on the horizontal axis and the measured value on the vertical axis. However, the size of each point is plotted as The magnitude of the deviation calculated by the deviation calculation unit 301 (the larger the deviation, the larger the deviation) is displayed. FIG. 5 shows an example in which a pair of the average value of the control value and the average value of the measurement value per day is displayed for 7 days. Here, the larger the deviation from the reference line 213 is, the larger the circle is used to represent it. For example, since the point 201b is outside the allowable range and has the largest deviation from the reference line 213, it is represented by the largest circle.

If the display is performed in this way, the monitor can check the control value and measurement value of each point, and also intuitively grasp the deviation of the point, so that the progress of deterioration can be easily grasped. In addition, in addition to plotting the size of the dots as the size corresponding to the deviation, it is also possible to paint in the color (hue) corresponding to the deviation, and in short, it is sufficient to draw the dots in a form corresponding to the deviation.

As described above, according to the second embodiment, it is possible to more easily and quickly determine the abnormality of the heater.

As described above, in the present invention, the display unit displays that the points determined by the paired control value and measurement value selected by the selection unit are arranged on a two-dimensional plane coordinate axis with the control value and the measurement value. The resulting graph is displayed by superimposing the allowable range on the graph. As a result, according to the present invention, the user can quickly determine the deterioration by visually checking the display, and can more easily and quickly determine the abnormality of the heater.

Here, the reference line will be described in more detail. As the reference line, a reference line obtained by fold-approximating the heater characteristics may be used. The reference line after the polyline approximation is composed of one or more line segments (first-order equations) on a two-dimensional plane coordinate with the control value and the measurement value as axes. By setting the allowable range by using the reference line after the polyline approximation as described above, the amount of data held as the allowable range can be greatly reduced. The reference line is composed of a combination of straight lines (first-order equations), so the allowable range is also composed of a combination of straight lines (first-order equations), so the amount of data is extremely small.

For example, the heater characteristics of a heater in a normal state may be measured, a polyline approximation may be used, and a reference line may be obtained from the measured heater characteristics. A predetermined number of set points (inflection points) may be set on the obtained curve of the heater characteristics under predetermined conditions, and the set points set may be connected by a straight line (line segment) to serve as a reference line. In addition, the current of the heater (heating device) relative to the control value is measured at a predetermined number of measurement points to obtain a current value, and a predetermined number of set points based on the control value and the current value are set, and the phases are linearly divided Neighboring setpoints can be used as a baseline.

Nine set points are set on a curve on a two-dimensional plane coordinate axis with a control value and a measurement value. In addition, each set point is set at least at the minimum value of the control value and the maximum value of the control value. Next, two adjacent set points are connected to each other with a straight line to create a reference line. For example, 9 set points are connected in order to create a reference line. The reference line is composed of 8 line segments.

In addition, the set point for creating the reference line may be set as shown below. First, on a two-dimensional plane coordinate with the control value and the measured value on the axis, the set points are arranged corresponding to the minimum and maximum values of the control value on the curve showing the characteristics of the heater, and the first approximation that connects them is set. line. In addition, a predetermined upper tolerance line and a lower tolerance line are set for the first approximation line. The area sandwiched by the upper tolerance line and the lower tolerance line becomes a candidate for the tolerance range.

In the state where the first approximation line is determined using the two set points as described above and the candidate of the allowable range is set, the judgment curve falls within the candidate of the allowable range and the maximum deviation of the first approximation line from the curve is less than a preset allowable Deviations. In the case where the curve falls within the allowable range and the maximum deviation is less than the allowable deviation, the first approximation line is used as the reference line.

On the other hand, when a region where the curve exceeds the allowable range is generated, the position where the deviation from the curve is the maximum in the negative direction of the measured value and the positive direction of the measured value with respect to the curve are obtained for the first approximation line. Where the deviation is at its maximum.

Next, a new set point is added to the obtained curve at the two positions. Next, a new second approximation line to be connected by adding four control points is set. In addition, a predetermined upper tolerance line and a lower tolerance line are set for the new second approximation line.

It was confirmed that the curve falls within the allowable range formed based on the upper allowable value line and the lower allowable value line obtained in this way, and the maximum deviation between the second approximation line and the curve is smaller than the allowable deviation. For example, since the curve falls within the allowable range and the maximum deviation of the second approximation line from the curve is less than the allowable deviation at this stage, the second approximation line is used as the reference line.

According to the above-mentioned method of making the reference line, by appropriately setting the maximum deviation, it is possible to set an allowable range in which practical deterioration determination can be performed without unnecessarily increasing the set point. In addition, by using the setting condition of the allowable deviation, it is possible to determine the approximation curve only by comparing the allowable deviation with the maximum deviation without comparing with the allowable range.

In addition, a reference line may be prepared as described below. First, for a heater (heating device) in a normal state, a plurality of control values are set within a range of minimum / maximum control values, and a heater current value is measured at each set control value. For example, the control value is changed within a range of 0% to 100% with a width of 10%, and the heater current value is measured at each control value. As a result of this measurement, a plurality of set points based on the obtained control values and heater current values are used, and a polyline obtained by connecting adjacent setpoints with a straight line is used as a reference line for approximating the characteristic of the heater. .

In addition, the present invention is not limited to the embodiments described above, and it is obvious that a large number of modifications and combinations can be implemented by those skilled in the art within the technical idea of the present invention.

Claims (7)

A deterioration diagnosis device comprising: a first storage unit storing an allowable range for determining deterioration of a heating device as a deterioration diagnosis object; the allowable range is based on a current value relative to a control value on a reference line; The upper allowable value and the lower allowable value are set. The reference line indicates a characteristic of a heater constituting the heating device in a normal state; a control value acquisition unit configured to acquire a control value for controlling the heater; a current measurement unit It is configured to measure a current supplied to the heater in accordance with a control value obtained by the control value acquisition unit to obtain a measurement value; and a second storage unit to store the control value and the control value obtained by the control value acquisition unit in a time series. A pair of measurement values measured by the current measurement unit; a selection unit configured to select a pair of control values and measurement values corresponding to the received selection instruction from the second storage unit; a first display control unit, which The graph is configured to display a graph on the display section, and the graph is formed by a pair of control values and measurements selected by the selection section. The points determined by the values are arranged on a two-dimensional plane coordinate with the control value and the measurement value as axes; and a second display control section configured to overlap the allowable range stored in the first storage section with The graph displayed on the display section is displayed. The deterioration diagnosis device according to claim 1, wherein the first storage section stores the reference line, and the second display control section is configured to display the reference line superimposed on the graph displayed on the display section. . The deterioration diagnosis device according to claim 1 or 2, further comprising: a deviation calculation unit configured to obtain deviations of the paired control value and measurement value from the reference line selected by the selection unit; and a third The display control unit is configured to arrange the points of the deviation calculated by the deviation calculation unit on a two-dimensional plane coordinate based on time and the deviation axis, and display the tolerance range stored in the first storage unit on the foregoing. On the display. The degradation diagnosis device according to claim 1 or 2, further comprising a deviation calculation unit configured to obtain a deviation of the paired control value and measurement value selected by the selection unit from the reference line, and the deviation is calculated from the reference line. The first display control unit draws points determined by the paired control value and measurement value selected by the selection unit as points in a form corresponding to the magnitude of the deviation obtained by the deviation calculation unit, and further, A graph in which the point is arranged on a two-dimensional plane coordinate axised with the control value and the measurement value is displayed on the display unit. The deterioration diagnosis device according to claim 1 or 2, wherein the reference line is a reference line obtained by approximating a characteristic of the heater, and the heater characteristic indicates a control value of the heater and a corresponding current when the heater characteristic is normal. Relationship. The deterioration diagnosis device according to claim 3, wherein the reference line is a reference line obtained by approximating a characteristic of the heater, and the heater characteristic indicates a relationship between a control value of the heater and a corresponding current when the heater characteristic is normal. . The degradation diagnosis device according to claim 4, wherein the reference line is a reference line obtained by approximating a characteristic of the heater, and the heater characteristic indicates a relationship between a control value of the heater and a corresponding current when the heater characteristic is normal. .