JP7147124B2 - Temperature controller and temperature control method - Google Patents

Description

The present invention relates to a temperature controller and a temperature control method.

There is a control target that controls the temperature of the entire bath by controlling one load, such as a constant temperature bath. In the case of such a controlled object, even if the temperature of a location where a load exists, such as a heater, stabilizes near the target temperature and becomes a steady state, the temperature at a location away from the load may be out of the target range. There is Especially for applications such as environmental tests, it is important that all points are within the target temperature range. Therefore, it is necessary to use temperature sensors at multiple points as input and perform control so that the overall temperature falls within the target range. be.
As prior art documents for control using a plurality of temperature sensors as inputs, Patent Document 1 discloses a temperature control method for a microwave oven, and Patent Document 2 discloses a temperature control method for a dryer.

Conventionally, in such a case, the temperatures of all monitored locations were adjusted to fall within the target range by continuing heating and cooling while manually checking the temperatures of the target locations.
In order to automate such adjustment to some extent, Non-Patent Document 1 describes a function that uses a measured value adjusted (biased) by a preset temperature, that is, a "pseudo measured value" while keeping the target value as it is. , “PV bias function” is disclosed. By performing control using the pseudo-measured values in this way, it is a function that makes it easier for the temperatures at all monitored locations to fall within the target range.

JP-A-11-173559 Japanese Patent Application Laid-Open No. 2003-222470

https://www. rkcinst. co. jp/glossary/7616/ (obtained on December 23, 2019)

However, in this PV bias function, the temperature set as the bias is controlled to a steady state once, and an appropriate value is manually set by the user in consideration of the positional relationship between the point where the target range is not reached and the heat source. had to set. Therefore, whether or not this function can be appropriately controlled depends greatly on the user's experience and senses, and since the settings are complicated, automation has been desired.

SUMMARY OF THE INVENTION In view of the above, it is an object of the present invention to provide a temperature controller and a temperature control method capable of automatically performing control so that the temperatures of all monitored locations to be controlled fall within a target range. .

(Configuration 1)
A temperature control device for controlling the temperature of a temperature controlled object based on a target temperature and a measured temperature of the temperature controlled object,
the measured temperatures are obtained from a plurality of locations subject to temperature control;
calculating the ratio of the difference values between the upper limit value and the lower limit value of the steady state temperature range allowed as the steady state of the temperature control object and the target temperature;
a difference value between the maximum value of a plurality of measured temperatures obtained at the same timing and the target temperature; a difference value between the minimum value of the plurality of measured temperatures obtained at the same timing and the target temperature; Based on the ratio and, calculate the pseudo measurement value at the timing,
A temperature controller that controls the temperature of the temperature-controlled object based on the pseudo-measured value and the target temperature.

(Configuration 2)
The pseudo-measured value is calculated by the following formula,
PV′=B×(ab)/A+b
In the above formula, PV' is the pseudo-measured value, A is the difference value between the upper limit value of the steady temperature range and the target temperature, B is the difference value between the lower limit value of the steady temperature range and the target temperature, and a is The temperature controller according to configuration 1, wherein the maximum value of the measured temperature and b is the minimum value of the measured temperature.

(Composition 3)
The temperature control according to configuration 1 or 2, wherein an alarm is output when a difference between the maximum value of the measured temperature and the minimum value of the measured temperature is greater than the difference between the upper limit value and the lower limit value for determination. Total.

(Composition 4)
4. The temperature controller according to any one of configurations 1 to 3, wherein an alarm is output when the maximum value of the measured temperature exceeds the upper limit of the steady temperature range.

(Composition 5)
A temperature control method for controlling the temperature of a temperature controlled object based on a target temperature and a measured temperature of the temperature controlled object by a temperature controller comprising a calculation unit and a control unit,
the measured temperatures are obtained from sensors installed at a plurality of locations of the temperature control target;
calculating a ratio of difference values between an upper limit value and a lower limit value of a steady temperature range allowed as a steady state of the temperature control object and the target temperature,
a difference value between the maximum value of a plurality of measured temperatures obtained at the same timing and the target temperature; a difference value between the minimum value of the plurality of measured temperatures obtained at the same timing and the target temperature; A pseudo measurement value at the timing is calculated by the calculation unit based on the ratio,
A temperature control method, wherein the control unit controls the temperature of the temperature controlled object based on the pseudo-measured value and the target temperature.

According to the temperature controller and temperature control method of the present invention, it is possible to automatically perform control so that the temperatures of all monitored locations to be controlled fall within the target range.

1 is a schematic configuration diagram showing a temperature controller of an embodiment according to the present invention; FIG. It is a conceptual diagram explaining the relationship between the conventional method and the method according to the present invention. 4 is a flow chart explaining the operation of the temperature controller of Embodiment 1 according to the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings. It should be noted that the following embodiment is one mode for embodying the present invention, and does not limit the scope of the present invention.

<Embodiment>
FIG. 1 is a schematic configuration diagram showing a portion related to the present invention of a temperature controller according to an embodiment of the present invention.
The temperature controller 100 is a device that controls the load 210 based on the measured values (PV) and preset target values (SV) from the plurality of sensors 231 to 23N that measure the temperature of the temperature controlled object 220, and will be described later. It has a calculation unit 120 that performs calculation of a pseudo-measured value, etc., and a control unit 110 that controls the output to the load based on the PV and the target value SV.
In this embodiment, the control method in the control unit 110 is PID control, the temperature controlled object 220 is a constant temperature bath, the load 210 is a heater, and the sensors 231 to 23N are temperature sensors such as thermocouples.
Further, in this embodiment, as shown in FIG. 1, there is one heat source, and a plurality of sensors are installed at various locations to be temperature-controlled so as to monitor the temperature of the relevant locations. .
Further, in this embodiment, the target value SV and the temperature range allowed in the steady state of the controlled object are set in advance by an input unit (not shown) or the like.

<Conventional method>
FIG. 2 is a conceptual diagram for explaining the relationship between the conventional control result and the control result of the present invention.
The graph shown in the upper part of FIG. 2 is a conceptual diagram showing the result of normal PID control, which is a conventional method. The horizontal axis of the graph indicates time, the vertical axis indicates temperature, the thick line indicates the measured value (PV) at the point (measurement point) closest to the heat source, and SV is the target value.
Further, the thin line above the PV indicates the maximum value a among the plurality of sensor measurement values, and the thin line below the PV indicates the minimum value b among the plurality of sensor measurement values. The upper and lower dashed lines indicate the upper and lower limits of the steady temperature range, which is the allowable temperature range in the steady state.
In this way, even though the measurement point is in a steady state, other locations may be out of the steady temperature range.

The lower part of FIG. 2 is a control result when this method is used, and is a conceptual diagram when controlling so that the pseudo-measured value PV' described later becomes the target value SV. I know there is.

<Method of the present invention>
The details of this method will be described below with reference to FIG.
First, difference values between SV and the upper and lower limits of a preset steady-state temperature range, which is a temperature range allowed in a steady state, are calculated. In FIG. 2, A is the difference value between the upper limit value and the SV, and B is the difference value between the lower limit value and the SV.

Next, among the measured values obtained at the same timing, the maximum and minimum values are recorded. Note that the same timing does not have to be exactly the same, and is a concept with some margin such as a delay. In FIG. 2, the maximum value is a and the minimum value is b.

Next, using the ratio of A and B, a pseudo-measured value PV', which is the apparent PV, is calculated. PV' is set so that the ratio of the difference between the maximum value a, the maximum value b, and PV' becomes the ratio of A and B.
Specifically, PV' is set as in Equation 1 below.
(Formula 1)
PV′=B×(ab)/A+b

By calculating the pseudo-measured value PV' in this way and inputting PV' into the control unit as the current measured value for control, the relationship between the upper and lower limits of the steady-state temperature range and the target value is maintained. Since control can be performed while the pressure is maintained, control can be performed so that all points are within the steady range.

<Alarm function>
It should be noted that it is important to set a steady temperature range depending on the controlled object such as a constant temperature bath, and if the steady temperature range is not appropriately set, desired results may not be obtained. For example, it is conceivable that the upper limit of the steady temperature range is too low and the measured value at a certain point exceeds the upper limit of the steady temperature range. In this case, the method cannot be used because no further heating is possible. In such a case, there is a high possibility that the steady-state temperature range is set incorrectly.
Moreover, when the difference between the maximum value and the minimum value of the measured values is larger than the width of the steady temperature range, there is a possibility that the steady state will not be within the steady temperature range.
Therefore, such a case is dealt with by outputting an alarm prompting the user to review the steady-state temperature range, adjust the position of the heat source, adjust the stirring device, and the like.
In this embodiment, the alarm is determined based on the case where the difference between the maximum value and the minimum value is larger than the width of the steady temperature range.

<Action>
Next, the processing operation of the temperature controller 100 according to the first embodiment will be described with reference to the flowchart of FIG.
Note that the period from start to end in the processing of FIG. 3 will be described below assuming a so-called rise period from the start of control of the constant temperature bath to a steady state using a temperature controller.

First, control is started, and measured values are obtained from all the sensors (CH) 231 to 23N in S310. The steady-state temperature range (upper limit and lower limit) and the target value SV are input to the temperature controller 100 by an input unit or the like (not shown). Also, when the steady-state temperature range and SV are input, the calculation unit 120 calculates the ratio (B/A in Equation 1 above) for calculating the pseudo-measured value.

Next, in S320, the calculation unit 120 sets the difference value PVmax−PVmin between the maximum measured value PVmax and the minimum measured value PVmin. Then, it is determined whether or not this difference value is equal to or less than the width (upper limit value - lower limit value) of the steady temperature range. If PVmax-PVmin is greater than the width of the steady temperature range, it is determined that there is a problem with the setting of the steady temperature range, the position of the heat source, etc., and the process proceeds to S330 (S320: NO→S330). At S330, the temperature controller 100 outputs an alarm to an external device (not shown) such as a display indicating that adjustment is necessary due to an abnormality in the setting, and proceeds to S340.

On the other hand, if PVmax-PVmin is equal to or less than the width of the steady temperature range, it is assumed that the setting of the steady temperature range is normal, and the process proceeds to S340 (S320: YES→S340).
In S340, the calculation unit 120 calculates the pseudo measured value PV' based on the maximum value and the minimum value of the measured values obtained at the same timing and the ratio of the difference between the steady temperature range and the target value. Specifically, the pseudo measured value PV' is calculated based on Equation 1 above.
Then, the calculation unit 120 outputs the pseudo measured value PV' to the control unit 110 as PV, and proceeds to S350.

At S350, the control unit 110 determines whether or not the steady state is established based on the pseudo measured value PV' and the target value SV. If it is not in a steady state, the control is continued and the process proceeds to S310, and the loop operation follows (S350: NO→S310).
On the other hand, if it is in a steady state, the start-up control is finished (S350: Yes→End).
In the present embodiment and FIG. 3, for the sake of explanation of the start-up control process, it is assumed that the process ends when the steady state is reached, but even when the steady state is reached, the calculation process continues. may be configured to implement In that case, the process is configured to be performed until the operation of the temperature controller 100 is substantially stopped, such as by turning off the power.

<effect>
As described above, according to the temperature controller 100 of the first embodiment, control can be performed while maintaining the relationship between the upper and lower limits of the steady-state temperature range and the target value. can be automatically controlled so that the temperature at the monitored location is within the steady-state temperature range.
In addition, since it is configured to output an alarm when the width of the maximum and minimum values of the measured values is larger than the preset steady-state temperature range, even if the conditions are not applicable to this method. In addition, the user can be prompted to adjust the steady-state temperature range and control environment.

<Other configurations>
In the present embodiment, the operation of the temperature controller 100 has been described when the load is a heater. The method can also be used in the same way. In this case, for a part of the condition determination for the alarm output, the reference for the alarm output is set opposite to the case where the load is the heater. For example, an alarm is output when the minimum measured value is below the lower limit of the steady-state temperature range.

Further, in the present embodiment, the case where the control unit 110 performs PID control has been described as an example, but it is sufficient if the control is performed using the current measured value, and the control is performed using arbitrary feedback control. may be configured to

Further, in the present embodiment, the calculation unit 120 is configured to calculate the ratio (A and B in the above formula 1) for calculating the pseudo measurement value PV' at the timing when the steady temperature range and SV are input. However, it may be configured to be calculated at an arbitrary timing up to the calculation of the pseudo measured value PV'.

Further, the temperature controller according to the present embodiment outputs an alarm by determining whether the difference value PVmax-PVmin between the maximum measured value PVmax and the minimum measured value PVmin is equal to or less than the width of the steady temperature range. However, it is not limited to this. For example, when only PVmax or only PVmin exceeds the upper limit of the steady temperature range, or when both PVmax and PVmin are below the lower limit of the steady temperature range despite the steady state It may be configured to output an alarm. With this configuration, the user can be prompted to adjust the control environment so that the technique can be used according to various control conditions.

It should be noted that each configuration in each of the above-described embodiments may be configured as hardware using a dedicated circuit or the like, or may be implemented as software on a general-purpose circuit such as a microcomputer. good.

Although the present invention has been described with reference to the embodiments, the present invention is not limited to the above-described embodiments. Various modifications that can be understood by those skilled in the art can be made to the configuration and operation of the present invention without departing from the scope of the present invention.

Reference Signs List 100 Temperature controller 110 Switching unit 120 Output unit 210 Load 220 Temperature control pair 231 to 23N Sensor

Claims (4)

A temperature control device for controlling the temperature of a temperature controlled object based on a target temperature and a measured temperature of the temperature controlled object,
the measured temperatures are obtained from a plurality of locations subject to temperature control;
calculating the ratio of the difference values between the upper limit value and the lower limit value of the steady temperature range allowed as the steady state of the temperature control target and the target temperature;
a difference value between the maximum value of a plurality of measured temperatures obtained at the same timing and the target temperature; a difference value between the minimum value of the plurality of measured temperatures obtained at the same timing and the target temperature; Based on the ratio and, calculate the pseudo measurement value at the timing,
characterized by controlling the temperature of the temperature-controlled object based on the pseudo-measured value and the target temperature ;
The pseudo-measured value is calculated by the following formula,
PV′=B×(ab)/A+b
In the above formula, PV' is the pseudo-measured value, A is the difference value between the upper limit value of the steady temperature range and the target temperature, B is the difference value between the lower limit value of the steady temperature range and the target temperature, and a is A temperature controller, wherein the maximum value of the measured temperature and b is the minimum value of the measured temperature. 2. An alarm is output when the difference between the maximum value of the measured temperature and the minimum value of the measured temperature is greater than the difference between the upper limit value of the steady temperature range and the lower limit value of the steady temperature range. The temperature controller described in . 3. The temperature controller according to claim 1, wherein an alarm is output when the maximum value of said measured temperature exceeds the upper limit of said steady temperature range. A temperature control method for controlling the temperature of a temperature controlled object based on a target temperature and a measured temperature of the temperature controlled object by a temperature controller comprising a calculation unit and a control unit,
the measured temperatures are obtained from sensors installed at a plurality of locations of the temperature control target;
calculating a ratio of difference values between an upper limit value and a lower limit value of a steady temperature range allowed as a steady state of the temperature control object and the target temperature,
a difference value between the maximum value of a plurality of measured temperatures obtained at the same timing and the target temperature; a difference value between the minimum value of the plurality of measured temperatures obtained at the same timing and the target temperature; A pseudo measurement value at the timing is calculated by the calculation unit based on the ratio,
The temperature of the temperature controlled object is controlled by the control unit based on the pseudo-measured value and the target temperature ,
The pseudo-measured value is calculated by the following formula,
PV′=B×(ab)/A+b
In the above formula, PV' is the pseudo-measured value, A is the difference value between the upper limit value of the steady temperature range and the target temperature, B is the difference value between the lower limit value of the steady temperature range and the target temperature, and a is The temperature control method , wherein the maximum value of the measured temperature and b is the minimum value of the measured temperature .

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