KR20200132684A - Temperature controller and abnormality determination method - Google Patents

Abstract

The present invention is to more reliably prevent damage to a heater due to a sensor deviating from an appropriate measurement point. The present invention relates to a temperature controller and an abnormality determination method for controlling the temperature of a control object. According to the present invention, a measurement unit (102) measures the temperature of a heater (101). A calculation unit (103) calculates a control value for controlling the heater (101) based on the measurement temperature measured by the measurement unit (102) and a preset temperature. A control unit (104) outputs an upper limit of the control value as a control value when the calculated value calculated by the calculation unit (103) exceeds the preset upper limit of the control value. A detection unit (105) detects that the calculated value calculated by the calculation unit (103) exceeds the upper limit of the control value output from the control unit (104). The measurement unit (106) measures the time during which the state in which the detection unit (105) detects that the calculated value has exceeded the upper limit of the control value output from the control unit (104) continues.

Description

Temperature controller and abnormality judgment method {TEMPERATURE CONTROLLER AND ABNORMALITY DETERMINATION METHOD}

The present invention relates to a temperature controller and an abnormality determination method for controlling a temperature of a control object.

A temperature controller that regulates the temperature of various temperature environments, displays a numerical value of the temperature of the monitored object detected using a temperature sensor such as a thermocouple or a resistance thermometer, and also displays a control value for the heater according to the detected temperature and the set temperature. And control the temperature of the monitored object.

By the way, since the heater is damaged if handled incorrectly, the following alarm settings and control values can be generally set in a device that controls a heater such as a temperature controller (see Patent Document 1 and Patent Document 2). The user of the heater uses this function to output an alarm and also limits the current flowing through the heater.

ㆍMonitoring the temperature to prevent heating above the temperature specified by the heater manufacturer (temperature upper limit alarm).

ㆍMonitoring of the rate of temperature change (temperature change rate alarm) to ensure that the heating rate does not exceed the heating rate specified by the heater manufacturer.

ㆍMonitors the upper limit of the control value (MV value) of the temperature controller and issues an alarm when it exceeds the upper limit of alarm (MV upper limit alarm).

ㆍSet the upper limit (control value upper limit) of the control value (MV value) so that the temperature controller does not output more than necessary (control value upper limit setting).

ㆍMeasures the current flowing through the heater and generates an alarm when a current exceeding the set value flows (overcurrent alarm).

Patent Document 1: Japanese Patent Laid-Open No. Hei 09-243098 Patent Document 2: Japanese Patent Laid-Open No. 01-298385

By the way, as described above, if the upper limit (the upper limit of the control value) of the control value (MV value) is set to, for example, 80%, even if the MV value obtained by calculation such as PID control from the detected temperature and the set temperature is 100%. , The MV value actually output becomes 80% set as the upper limit of the control value.

In the case of normal control, the period in which the result of the PID operation exceeds the upper limit of the control value is often almost constant. On the other hand, depending on the condition of the abnormal state, the MV value calculates an MV value exceeding the upper limit of the control value until the abnormal condition that has occurred is improved. For example, if the sensor deviates from an appropriate measurement point and is measuring the ambient temperature rather than the temperature of the heater, the measured value output by the sensor becomes a value significantly lower than the set value, and the temperature controller increases the temperature to the set value. Make it bigger. When the calculated MV value reaches the upper limit of the control value, an MV value larger than that is not output. However, if this state continues for a long time, the heater becomes a high temperature that exceeds the range of use and may cause damage.

In addition, when a disconnection or the like occurs in the circuit to which the sensor is connected, the temperature control system enters the same control state as described above. However, with regard to disconnection, this state is detected by a general temperature controller, and when disconnection is detected, the MV value is set to 0%, so that damage to the heater is not caused.

The problem of heater breakage when the above-described sensor deviates from an appropriate location can be addressed by issuing an alarm using, for example, an upper alarm limit value. When the calculated MV value exceeds the set alarm upper limit value continues for a certain period of time, an alarm can be issued to respond to the above-described problem. For example, if the upper limit of the alarm is set, the time at which damage does not occur is set as the time limit for issuing the aforementioned alarm. According to this control, even if the sensor deviates from an appropriate measurement point and the MV value reaches the upper limit of the control value, an alarm is issued after a certain period of time, so that an abnormal state is recognized by the manager (user). If recognized by the manager, the manager can take action such as stopping the operation of the temperature controller, checking the abnormal condition, and resolving the abnormal condition, thereby preventing damage to the heater.

By the way, in this type of control, in many cases, the upper limit of the above-described control value is changed from the initial setting in response to changes in the control environment. For example, there is a case where the upper limit of the control value initially set at 80% is changed to 70%. In such a change, it is necessary to change the upper alarm limit from 80% to 70%. However, even if the upper limit of the control value is changed, the change of the upper limit of the alarm of the upper limit of the MV value may be forgotten in some cases. For example, even if the upper limit of the control value is changed to 70%, the change of the upper limit of the alarm is forgotten, and the upper limit of the alarm remains at 80%.

In this case, even if the sensor deviates from the appropriate measurement point and the MV value becomes the upper limit of the control value, the upper limit of the alarm has not been reached, and thus no alarm is issued. If the alarm is not issued, the above-described actions by the administrator are not performed, resulting in damage to the heater. Although there is a degree of freedom for issuing an alarm using the upper alarm limit, the upper limit of the alarm can be set separately from the upper limit of the control value, but as described above, the heater is operated in an abnormal state such as the sensor is out of the appropriate measurement point. There is a problem in that damage may not be prevented due to forgetting the setting of the upper alarm limit value or the like.

The present invention has been made to solve the above-described problems, and an object of the present invention is to more reliably prevent damage to a heater due to a sensor being deviated from an appropriate measurement point.

A temperature controller according to the present invention is a temperature controller that controls a heating ability of a heater to control a temperature of a control object to a preset temperature, and includes a measurement unit configured to measure the temperature of the heater, and a measurement temperature measured by the measurement unit. A calculation unit configured to calculate a control value for controlling the heater based on a preset set temperature, and a control unit that outputs the control value upper limit as a control value when the calculated value calculated by the calculation unit exceeds a preset control value upper limit Wow, the detection unit configured to detect that the calculated value calculated by the calculation unit exceeds the upper limit of the control value output from the control unit, and the time during which the detection unit detects that the calculated value exceeds the upper limit of the control value output from the control unit. A measurement unit configured to measure, a determination unit configured to determine an abnormality when the time measured by the measurement unit exceeds a predetermined determination time, and an output unit that outputs an alarm when the determination unit determines that it is abnormal.

In one configuration example of the temperature control system, the calculation unit has a plurality of control contents used for calculation of the control value.

In one configuration example of the temperature controller, a determination time is set for each control content used by the calculation unit to calculate a control value.

In addition, the abnormality determination method according to the present invention includes a first step of calculating a control value for controlling the heater based on the measured temperature of the heater and a preset set temperature, and the calculated value calculated in the first step, A second step of detecting the exceeding of a preset upper limit of the control value, and a third step of measuring the time duration in which the state in which the calculated value exceeds the upper limit of the control value continues to be detected, and a third step And a fourth step of judging that it is abnormal when the time measured at exceeds a predetermined judgment time.

In one configuration example of the abnormality determination method, a plurality of control contents used for calculating a control value are provided.

In one configuration example of the abnormality determination method, a determination time is set for each control content used for calculating a control value.

As described above, according to the present invention, according to the present invention, the detection unit measures the time during which the state in which the detection unit detects that the calculated value exceeds the upper limit of the control value output from the control unit continues, and the time to measure exceeds a predetermined determination time Since the lower surface is judged to be abnormal, it is possible to more reliably prevent damage to the heater due to the sensor being deviated from an appropriate measurement point.

1 is a configuration diagram showing a configuration of a temperature control system according to an embodiment of the present invention.
2 is a flowchart for explaining an abnormality determination method according to an embodiment of the present invention.
3 is a configuration diagram showing a hardware configuration of a calculation unit, a detection unit, a measurement unit, and a determination unit of a temperature controller according to an embodiment of the present invention.

Hereinafter, a temperature controller according to an embodiment of the present invention will be described with reference to FIG. 1. This temperature controller controls the heating ability of the heater 101 to control the temperature of the control object to a preset temperature. This temperature controller includes a measurement unit 102, a calculation unit 103, a control unit 104, a detection unit 105, a measurement unit 106, a determination unit 107, an output unit 108, and a storage unit 109. Equipped.

The measurement unit 102 measures the temperature of the heater 101. The calculation unit 103 calculates a control value for controlling the heater 101 based on the measurement temperature measured by the measurement unit 102 and a preset temperature. The calculation unit 103 calculates, for example, a control value based on the control contents stored (set) in the storage unit 109.

The control unit 104 outputs the calculated value calculated by the calculation unit 103 as a control value. Further, the control unit 104 outputs the upper limit of the control value as a control value when the calculated value calculated by the calculation unit 103 exceeds a preset upper limit of the control value. The control unit 104 uses, for example, the upper limit of the control value stored (set) in the storage unit 109. For example, 80% is set as the upper limit of the control value. In this case, the control unit 104 outputs 80% of the upper limit of the control value as a control value to the heater 101 side when the calculated value calculated by the calculation unit 103 exceeds 80% and becomes, for example, 90%.

The detection unit 105 detects that the calculated value calculated by the calculation unit 103 exceeds the upper limit of the control value. The measurement unit 106 measures the time during which the state in which the detection unit 105 detects that the calculated value exceeds the upper limit of the control value output from the control unit 104 continues. The determination unit 107 determines that it is abnormal when the time measured by the measurement unit 106 exceeds a predetermined determination time. The judgment time can be, for example, 50 seconds. The output unit 108 performs abnormal processing (transition to an operation amount in case of abnormality, an alarm is issued, etc.) when the determination unit 107 determines that it is abnormal. For example, the indication that an abnormality has occurred is displayed on a display unit not shown. Further, it is notified as an alarm by voice or the like using a horn or a speaker.

According to the above-described embodiment, the detection unit 105 detects that the calculated value calculated by the calculation unit 103 exceeds the upper limit of the control value, and the measurement unit 106 measures the duration of this time, and the time to measure is determined. If it exceeds the time, it is judged as abnormal. In this way, the detection unit 105 does not refer to the upper limit of the alarm, but refers to the upper limit of the control value, and detects that the calculated value exceeds this value. According to the first embodiment, when the upper limit in the control value is changed, it is automatically reflected in the reference object in detection by the detection unit 105.

As a result, according to the embodiment, even if the position of the sensor is shifted by forgetting or incorrectly setting the setting of the upper limit of the alarm, the alarm is not issued, and the heater is generated due to the position of the sensor. It is possible to more reliably prevent the breakage.

By the way, in this type of PID control, as shown in Table 1 below, the PID constants and their set values (including the upper limit of the control value) so that the control can be performed with a plurality of control contents using different PID constants. As a set of control contents (PID set), set in the temperature controller. If a plurality of PID sets are set, controllability can be easily changed by changing the PID sets used for control. For example, a plurality of PID sets can be stored in the storage unit 109.

When a plurality of PID sets are set in this way, as shown in Table 2 below, the determination time may be set for each PID set (control content) used by the calculation unit 103 to calculate the control value. By doing in this way, it becomes possible to automatically set an appropriate judgment time according to the control contents.

Next, an operation example (abnormality determination method) of the temperature controller according to the embodiment will be described using the flowchart in FIG. 2.

First, in step S101, the calculation unit 103 calculates a control value for controlling the heater 101 based on the measured temperature of the heater 101 and a preset set temperature (first step). Next, in step S102, the detection unit 105 detects that the calculated value calculated by the calculation unit 103 exceeds the upper limit of the control value (second step). When the detection unit 105 detects that the calculated value exceeds the upper limit of the control value (yes in step S102), the measurement unit 106 at step S103 indicates that the calculated value exceeds the upper limit of the control value output from the control unit 104 It is determined whether or not the measurement of the time during which the state being detected continues has begun. When time measurement has not started (no in step S103), in step S104, the measurement unit 106 measures the time during which the state in which the calculated value exceeds the upper limit of the control value output from the control unit 104 is detected. And proceeds to step S105. In addition, when time measurement has started (yes in step S103), the process proceeds to step S105 (third step).

Next, in step S105, it is determined whether or not the measured time exceeds a predetermined judgment time. When the measured time exceeds the determination time (yes in step S105), in step S106, the measurement unit 106 stops (terminates) the measurement of the time, and in step S107, the determination unit 107 determines that it is abnormal ( Step 4). Further, the measurement of time continues as long as it is detected that the calculated value exceeds the upper limit of the control value (steps S101 to S105). If the determination unit 107 determines that there is an abnormality, in step S108, abnormal processing (transition to the operation amount in case of abnormality, alarm issuance, etc.) is performed. After the alarm is issued, the state is maintained until the cancel operation is performed in step S109.

In addition, as shown in Fig. 3, the calculation unit, control unit, detection unit, measurement unit, and determination unit of the temperature control system according to the above-described embodiment include a CPU (Central Processing Unit) 301 and a main memory unit 302. As a computer device including an external storage device 303, a network connection device 304, and the like, the CPU 301 operates (executes a program) by a program deployed in the main memory device, thereby determining the above-described functions (abnormality determination). Method) can be realized. The program is a program for a computer to execute the abnormality determination method shown in the above-described embodiment. The network connection device 304 connects to the network 305. In addition, each function can also be distributed over a plurality of computer devices.

In addition, the calculation unit, control unit, detection unit, measurement unit, and determination unit of the temperature control system in the above-described embodiment can be configured by a programmable logic device (PLD) such as a field-programmable gate array (FPGA). . For example, the above-described functions can be executed by providing each of a calculation unit, a control unit, a detection unit, a measurement unit, and a determination unit as circuits in the logic element of the FPGA. Each of the calculation circuit, the control circuit, the detection circuit, the measurement circuit, and the determination circuit can record in the FPGA by connecting a predetermined recording device. Further, each of the circuits recorded in the FPGA can be confirmed by a recording device connected to the FPGA.

As described above, according to the present invention, according to the present invention, the detection unit measures the time during which the state in which the calculated value exceeds the upper limit of the control value continues, and if the time to measure exceeds the predetermined judgment time, it is abnormal. Because of the judgment, it is possible to more reliably prevent damage to the heater due to the sensor being deviated from an appropriate measurement point.

In addition, it is clear that the present invention is not limited to the embodiments described above, and many modifications and combinations can be implemented by those of ordinary skill in the relevant field within the technical idea of the present invention. In the above-described embodiment, it is also possible to combine the issuance of an alarm using the upper alarm limit value. In addition, for example, in addition to the alarm shown in the above-described embodiment, an alarm may be issued when the measured temperature exceeds the set value. Also, when the current flowing through the heater exceeds a set value, an alarm can be issued. Also, if the voltage applied to the heater exceeds a set value, an alarm can be issued. By increasing the number of monitoring items, it can function as a more robust load protection function.

101 heater, 102 measurement unit 103 calculation unit 104 control unit 105 detection unit 106 measurement unit 107 determination unit 108 output unit 109 storage unit.

Claims (6)

As a temperature controller that controls the heating ability of the heater and controls the temperature of the control object to a preset set temperature,
A measuring unit configured to measure the temperature of the heater,
A calculation unit configured to calculate a control value for controlling the heater based on a measurement temperature measured by the measurement unit and a preset temperature,
A control unit that outputs the upper limit of the control value as a control value when the calculated value calculated by the calculation unit exceeds a preset upper limit of the control value;
A detection unit configured to detect that the calculated value calculated by the calculation unit exceeds an upper limit of a control value output from the control unit;
A measurement unit configured to measure a time during which a state in which the detection unit detects that the calculated value exceeds an upper limit of a control value output from the control unit continues;
A determination unit configured to determine as abnormal when the time measured by the measurement unit exceeds a predetermined determination time;
An output unit that outputs an alarm when the determination unit determines that it is abnormal
A temperature controller comprising a. The method of claim 1,
The temperature controller, wherein the calculation unit has a plurality of control contents used to calculate the control value. The method of claim 2,
The temperature controller, wherein the determination time is set for each control content that the calculation unit uses to calculate the control value. A first step of calculating a control value for controlling the heater based on the measured temperature of the heater and a preset temperature,
A second step of detecting that the calculated value calculated in the first step exceeds a preset upper limit of the control value; and
In the second step, a third step of measuring a time period during which a state in which the calculated value exceeds the upper limit of the control value is detected;
The fourth step of determining an abnormality when the time measured in the third step exceeds a predetermined determination time
An abnormality determination method comprising a. The method of claim 4,
An abnormality determination method comprising a plurality of control contents used for calculating the control value. The method of claim 5,
The abnormality determination method, characterized in that the determination time is set for each control content used to calculate the control value.

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