JP2001296901A - Controling apparatus and temperature controller and heat treating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce interference in controlling an object to be controlled with interference and also set a control parameter by correctly executing auto-tuning. SOLUTION: This system is provided with a plurality of heaters and a plurality of temperature sensors which are made individually correspond to each other and a plurality of PID control means 61-6n, and the mean temperature of the detected temperatures of the plurality of temperature sensors and a gradient temperature based on the detected temperatures are calculated by a mean temperature and gradient temperature calculating means 5, and an operation signal is outputted by each PID control means 61-6n so that the mean temperature or each gradient temperature can be set as a target value, and the operation signal from each PID control means 61-6n is distributed to each heater by a distributing means 7 so that the control of each PID control means 61-6n can be prevented from affecting the control of the other PID control means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for controlling a physical state such as a temperature and a pressure of a control object, a temperature controller for controlling the temperature of the control object, and a heat treatment apparatus using the temperature controller. The present invention relates to a technique suitable for controlling a controlled object having so-called interference, in which a plurality of state control means for controlling a physical state of a controlled object are provided, and the control by each state controlling means affects the control by another state controlling means. .

[0002]

2. Description of the Related Art As an object to be controlled of this kind, for example, as a heat treatment apparatus for a semiconductor process, there is a thermal oxidation apparatus shown in FIG. 26, and this thermal oxidation apparatus 18 oxidizes a silicon wafer. An oxide film is formed while flowing a necessary gas through a reaction tube 19 as a furnace.
The thermal oxidation device 18 is provided with a heat equalizing tube 2 surrounding a reaction tube 19.
In this example, three heaters 21 _{1 to} 21 ₃ and first to third temperature sensors 22 _{1 to} 22 ₃ individually corresponding to the plurality of heaters 21 _{1 to} 21 ₃ are provided. And
The temperature control is individually performed by the microcomputer 23 for each area (hereinafter, referred to as “zone”) corresponding to each set of the heater and the temperature sensor.

That is, the first heater 21 ₁ and the first heater 21 1
In the first zone of the upper temperature sensor 22 ₁ is disposed in, on the basis of the detection output of the first temperature sensor 22 _1, the first heater 21 ₁ so that the target temperature is operated, the second In a _second intermediate zone where the heater 21 ₂ and the second temperature sensor 22 ₂ are arranged, the second temperature sensor 22 ₂
The second heater 21 ₂ is operated to reach the target temperature on the basis of the detection output of, and in the lower third zone in which the third heater 21 ₃ and the third temperature sensor 22 ₃ are arranged, based on the detection output of the third temperature sensor 22 _3, the third heater 21 ₃ is operated so that the target temperature.

However, since each zone is thermally continuous, the amount of heat generated by the heater in one zone affects not only that zone but also the temperature sensors in other zones, so-called interference occurs.

[0005]

Due to such interference, temperature fluctuations become remarkable, especially during transients and disturbances, making it difficult to perform uniform temperature control. It is not easy to control.

Further, an optimum PID for a temperature controller
There is also a drawback that auto tuning for determining control parameters cannot be executed correctly.

Hereinafter, the reason why the auto tuning cannot be executed correctly will be described with reference to an example using simulation software for control (MATLAB).

First, as an example in which auto-tuning can be performed normally, a case will be described in which independent first and second controlled objects 24 ₁ and 24 ₂ without interference shown in FIG. 27 are controlled. This example is independent of what controls the two control target 24 _1, 24 _2, the first PID control means 25 _1, running auto-tuning, the second PID controller 25 _2, the target value Is used as ground to execute PID control. Here, 26 ₁ and 26 ₂ are adders for outputting a control deviation between the target value and the feedback amount.

FIG. 28 shows a first feedback amount PV1 (broken line) from the _first control object 241 in this system, a first operation amount MV1 (solid line) from the _first PID control means 251, Feedback amount PV2 (two-dot chain line) and second PID from the _second control target 24 ₂
The second manipulated variable from the control means 25 ₂ MV2 (dashed line)
Shows a waveform displayed on a scope, a limit cycle in which the first manipulated variable MV1 is turned on and off occurs, and the first PID control unit 25 uses the cycle and amplitude of the first feedback amount PV1. _One PID control parameter can be determined.

The feedback amounts PV1, PV2
Corresponds to, for example, a temperature detected by a temperature sensor in the temperature control, and the manipulated variables MV1 and MV2 are operations provided to operation means including a heater for heating the control target and an electromagnetic switch for turning on and off the power supply to the heater. Quantity.

Next, as shown in FIG. 29, a description will be given of a case where independent control is performed on a control object 27 having two-input (MV1, MV2) and two-output (PV1, PV2) interference.

As shown in FIG. 30, the control target 27 receives the first manipulated variable MV1 from the _first PID control means 251 to the first adder 28 and performs the first attenuation. Attenuated to 0.9 by the adder 29 and the second adder 30
On the other hand, the second manipulated variable MV2 from the _second PID control means 252 is supplied to the second adder 30 and is attenuated to 0.9 by the second attenuator 31 to the first operation amount MV2.
, And the added outputs of the adders 28 and 30 are respectively provided to the first and second delay elements 32 and 33. In this example, each operation amount MV
1, MV2 are added to the other at a ratio of 0.9 to cause interference with each other.

In the control object 27 having such interference,
When the first PID control means 25 ₁ executes auto-tuning and the second PID control means 25 ₂ executes PID control with the target value set to ground, as shown in FIG. In some cases, the ON / OFF limit cycle does not occur in MV1 (solid line). In such a case, the amplitude and cycle of the vibration of the first feedback amount PV1 (dashed line) cannot be measured correctly, and the parameters of PID control are also calculated. You will not be able to do it.

[0014] The reason that not the first on-off operation amount MV1 as the change of the first feedback amount PV1 Autotuning side second PID control means 25 ₂ on the side not the automatic tuning and interference occurs This is because it operates without permission. This is because the second manipulated variable MV2 (dotted line) is the first feedback quantity P
It can also be seen from the movement in the opposite direction to the change in V1.

As described above, in the case of a controlled object having interference, P
Auto-tuning for setting the control parameters of the ID cannot be performed, and the setting must be performed by trial and error. Therefore, it takes time to set, and it is difficult to obtain desired control characteristics.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has as its object to reduce the interference and set a control parameter even for a controlled object having interference. I do.

[0017]

In order to achieve the above-mentioned object, the present invention is configured as follows.

That is, the control device according to the present invention converts information from a plurality of detecting means for respectively detecting the physical state of the control object into information indicating the gradient of the physical state, and indicates the representative state of the physical state. Conversion means for converting the information into information; a plurality of state control means to which each piece of information from the conversion means is individually given; an operation signal from each state control means to a plurality of operation means; A distributing means for distributing the control so as to eliminate or reduce the influence on the control by the other state controlling means, and a control means provided at a preceding stage of the distributing means to restrict an operation signal from at least one of the state controlling means. Limiting means.

Here, the physical state means a state of various physical quantities such as temperature, pressure, flow rate, speed or liquid level.

The gradient of the physical state refers to a gradient of various physical quantities such as a temperature gradient, a pressure gradient, a flow rate gradient, and a speed gradient.

Further, the representative state of the physical state refers to a state representatively representing the physical state of the control target. For example, if the temperature is a temperature, the average temperature of the control target, the temperature at a certain position (for example, the center position), Say.

According to the present invention, control is performed by converting information from the plurality of detecting means into information indicating the gradient of the physical state and information indicating the representative state, that is, independent information without interference. Thus, the control by each state control means is distributed so as to eliminate or reduce the influence on the control by the other state control means, so that it is possible to reduce the interference in the control of the control target having the interference.

[0023] Further, since there is provided limiting means for limiting the operation signal from at least one of the state control means,
It is possible to perform control in which another state control is prioritized over state control in which the operation signal is restricted by the restricting means.

Further, the control device of the present invention calculates a deviation between information from a plurality of detecting means for respectively detecting a physical state of an object to be controlled and a plurality of target information individually corresponding to the plurality of detecting means. A conversion unit that converts the deviation of the information indicating the gradient of the physical state into a deviation of the information indicating the representative state of the physical state, and a deviation of the information indicating the gradient or the information indicating the representative state from the conversion unit. A plurality of state control means each outputting an operation signal as a control deviation, and an operation signal from each state control means, a plurality of operation means, the control by each state control means, the control by each state control means by other state control means A distributing means for distributing the signal so as to eliminate or reduce the influence on the control; and a distributing means provided before the distributing means for limiting an operation signal from at least one of the state control means. And a restriction means.

Here, the target information refers to information of a physical state control target, for example, a target temperature, a target pressure, a target flow rate, and the like.

According to the present invention, control is performed by converting information from a plurality of detecting means into information utilizing a gradient of a physical state or a representative state, that is, independent information without interference, and controlling the distribution by means of a distribution means. Since the control by the state control means is distributed so as to eliminate or reduce the influence on the control by the other state control means, it is possible to reduce the interference in the control of the control target having the interference.

[0027] Further, since there is provided limiting means for limiting an operation signal from at least one of the state control means,
It is possible to perform control in which another state control is prioritized over state control in which the operation signal is restricted by the restricting means.

Further, the temperature controller of the present invention converts the detected temperatures obtained from a plurality of temperature detecting means for detecting the temperature of the control object into a gradient temperature based on the plurality of detected temperatures. Conversion means for converting into temperature, a plurality of temperature control means each outputting an operation signal with the inclination temperature or the representative temperature from the conversion means as a control amount, and an operation signal from each of the temperature control means, Distributing means for distributing to a plurality of heating (or cooling) means for heating (or cooling) such that the control by each temperature control means does not affect or reduce the influence on the control by other temperature control means; And a limiter provided at a preceding stage to limit an operation signal from at least one of the temperature control means.

According to the present invention, the detected temperatures obtained from the plurality of temperature detecting means are defined as a gradient temperature and a representative temperature, that is,
Control by converting to independent information without interference,
Since the control by each temperature control means is distributed by the distribution means so as to eliminate or reduce the influence on the control by the other temperature control means, it is possible to reduce the interference in the control of the control target having the interference. Become. Also,
For example, when temperature control is performed by dividing a control target into a plurality of zones, control can be performed focusing on a specific zone using a detected temperature of a specific zone as a representative temperature.

Further, since a limiter for limiting an operation signal from at least one temperature control means is provided, the temperature control is limited to a temperature control other than the temperature control in which the operation signal is limited by the limiter, for example, to an average temperature as a representative temperature. This makes it possible to perform the temperature control in which the temperature control based on the inclination temperature is prioritized over the temperature control based on the tilt temperature.

Further, the temperature controller according to the present invention is characterized in that a detected temperature obtained from a plurality of temperature detecting means for respectively detecting a temperature of a control object and a plurality of target temperatures individually corresponding to the plurality of temperature detecting means. The conversion unit converts the deviation into a deviation of the gradient temperature, and converts the deviation into the representative representative temperature, and the operation signal as the control deviation using the deviation of the gradient temperature or the deviation of the representative temperature from the conversion unit. A plurality of temperature control means to be output, and an operation signal from each of the temperature control means, to the plurality of operation means, so as to eliminate or reduce the influence of the control by each temperature control means on the control by the other temperature control means. And a limiter that is provided in front of the distribution unit and restricts an operation signal from at least one of the temperature control units.

According to the present invention, control is performed by converting the detected temperature and the target temperature obtained from the plurality of temperature detecting means into the deviation of the inclination temperature and the deviation of the representative temperature, that is, independent information without interference. Since the control by each temperature control means is distributed by the distribution means so as to eliminate or reduce the influence on the control by the other temperature control means,
In the control of the control target having the interference, the interference can be reduced. In addition, for example, when temperature control is performed by dividing a control target into a plurality of zones, control can be performed focusing on a specific zone using a detected temperature of a specific zone as a representative temperature.

Further, since the limiter for limiting the operation signal from at least one temperature control means is provided, the temperature control is different from the temperature control in which the operation signal is limited by the limiter, for example, the temperature control based on the average temperature. Also, the temperature control can be performed with priority given to the temperature control based on the inclination temperature.

In one embodiment of the present invention, the representative temperature is an average temperature based on a plurality of detected temperatures, and at least one of the temperature control means outputs an operation signal using the average temperature as a control amount. Alternatively, it is a temperature control means to which a deviation of the average temperature is given.

According to the present invention, since the operation signal of the temperature control means based on the average temperature is limited by the limiter, it is possible to perform the temperature control in which the temperature control based on the gradient temperature has priority over the temperature control based on the average temperature. Become.

The heat treatment apparatus of the present invention comprises a temperature controller according to the present invention, a heat treatment furnace or a heat treatment plate to be controlled, and heating (or cooling) of the heat treatment furnace or the heat treatment plate.
And a plurality of temperature detecting means for detecting the temperature of the heat treatment furnace or the heat treatment board.

According to the present invention, the temperature of the heat treatment furnace or the heat treatment board is controlled by the temperature controller of the present invention.
Temperature control with reduced interference becomes possible.

[0038]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a schematic configuration diagram of a temperature control system using a temperature controller according to one embodiment of the present invention.

The temperature control system of this embodiment is
A plurality of heaters 1 for heating the control target 3 ₁~ 1n and multiple
Heater 1₁Temperature of the controlled object 3 individually corresponding to .about.1n
Temperature sensors 2 for detecting temperature₁~ 2n and these temperatures
Sensor 2₁2n based on the detected outputs of₁~
1n is operated and controlled via an electromagnetic switch (not shown)
A temperature controller 4 according to the present invention for controlling the temperature of the object 3;
Have.

The controlled object 3, which generates heat continuously to interference, a plurality of zones and each temperature sensor 2 ₁ to 2n is arranged close respectively corresponding to the heaters 1 ₁ 1n are Each is formed.

This temperature control system can be applied to, for example, the thermal oxidation apparatus 18 shown in FIG. 26 described above, and the control target 3 is a reaction tube 19 as a heat treatment furnace.
The first to third heaters ₁ 1 to 1 _3, by dividing the periphery of the reaction tube 19 and the first to third heaters 21 ₁ to 21 ₃ which is disposed, the first to third temperature sensors 2 ₁ the ~ 2 _3, in which can be applied as the first to third temperature sensors 22 ₁ to 22 ₃ which detects the temperature of each zone.

[0043] Figure 2 is a block diagram of a temperature controller 4 of Figure 1, the temperature controller 4 of this embodiment is based on the average temperature and the detected temperature of the temperature detected by the plurality of temperature sensors 2 ₁ to 2n Mean temperature / inclination temperature calculation means (hereinafter also referred to as "mode converter") for calculating the inclination temperature as described later.
5, the PID control means 6 ₁ ～6N as a plurality of temperature control means the average temperature or the gradient temperature calculated by the calculating means 5 are input, the PID control means 6 ₁
And a distribution means (hereinafter also referred to as a "pre-compensator") 7 for distributing the operation signal (operation amount) from 6n to each of the heaters _{11 to} 1n constituting the heating means at a predetermined distribution ratio as described later. ing. Mean temperature and gradient temperature calculating means 5, PID control means 6 ₁ ~6n and allocation means 7 is composed of, for example, a microcomputer.

Conventionally, as shown in FIG. 26 described above, the temperature is detected for each zone and the corresponding heater is individually controlled. However, in this embodiment, in order to eliminate the interference, the average is controlled. Temperature control is performed using the average temperature as the representative temperature calculated by the temperature / inclination temperature calculation means 5 and the plurality of inclination temperatures as control amounts.

[0045] The average temperature-gradient temperature calculating means 5 as the conversion unit, information from a plurality of temperature sensors 2 ₁ to 2n,
This is converted into information of one average temperature and a plurality of gradient temperatures. The reason for this is to make the information independent and easy to understand without interference. For example, the following calculation is performed. .

[0046] That is, the first temperature sensor 2 ₁ detection output S1, a second temperature sensor 2 _second detection output S2, ...
Calculation When the detection output Sn of the temperature sensor 2n of the n, the average temperature Tav shown below, the first gradient temperature Tt1, the second gradient temperature Tt2, the gradient temperature Tt _n-1 of ... the (n-1) I do.

Tav = (S1 + S2 +... Sn) ÷ n Tt1 = (S1 + S2 +... S_n-1) ÷ (n−1) −Sn Tt2 = (S1 + S2 +... S_n-2) ÷ (n-2) -S_n-1 ・ ・ Tt_n-1= S1−S2 where Tav is the number of temperature sensors 2₁~ 2n detection
The temperature is an average temperature, and the slope temperature Tt1 is a plurality of temperatures.
Sensor 2₁２2n to the temperature sensor 2₁~ 2_n-1And temperature sen
Temperature sensor 2 when divided into two₁~ 2_n-1
Is the difference between the average detected temperature and the detected temperature of the temperature sensor 2n.
The inclination temperature Tt2 is determined by a plurality of temperature sensors 2₁~ 2
_n-1To the temperature sensor 2₁~ 2_n-2And temperature sensor 2_n-1And two
Temperature sensor 2 when divided into two₁~ 2_n-2Average detected temperature
Degree and temperature sensor 2_n-1Is the difference from the detected temperature of
Thus, the slope temperature Tt_n-1Is the temperature sensor 2₁And temperature
Sensor 2 _TwoAnd the detected temperature difference.

Summarizing the above equations, the mode conversion matrix Gm
It can be expressed as follows using a matrix called.

[0049]

(Equation 1)

[0050] T = Gm · S However, T = the _{[Tav Tt1 Tt2 ...... Tt n-} 1] T S = [S1 S2 S3 ...... S n] T this embodiment, these average temperature Tav and a plurality of inclined The temperature is controlled using the temperatures Tt1 to Ttn _{- 1} as control amounts.

Note that the gradient temperature is not limited to this embodiment. For example, the following temperature conversion matrix Gm
As shown in (2), various gradient temperatures such as a temperature difference between detected temperatures of adjacent temperature sensors and a plurality of temperature sensors divided into two groups can be used.

[0052]

(Equation 2)

The gradient temperature is defined as a temperature difference between the average detected temperatures of each group obtained by dividing a plurality of temperature sensors into two groups, a temperature difference between the average detected temperatures of each group obtained by further dividing each group into two groups, Further, a range from a macro gradient temperature to a micro gradient temperature may be calculated and used, such as a temperature difference between the average detected temperatures of each group obtained by dividing each group into two.

In short, it suffices if the information can be controlled separately from the information indicating the temperature gradient and the average information.

[0055] The first PID control means 6 _1, average temperature,
Based on the control deviation of the average temperature and the target average temperature from gradient temperature calculating means 5, and outputs an operation signal so that the average temperature of the target average temperature distribution unit 7, the second PID controller 6 _2, An operation signal is distributed based on a control deviation between the first slope temperature and the first target slope temperature from the average temperature / slope temperature calculation means 5 so that the first slope temperature becomes the first target slope temperature. outputs to the means 7, a third PID controller 6 ₃ based on the control deviation between the second gradient temperature and a second target gradient temperature from the average temperature and gradient temperature calculating means 5,
An operation signal is output to the distributing means 7 so that the second inclination temperature becomes the second target inclination temperature, and so on.
The ID control means 6n determines the (n-1) th slope temperature based on the control deviation between the (n-1) th slope temperature and the (n-1) th target slope temperature from the average temperature / slope temperature calculation means 5. An operation signal is output to the distribution unit 7 so that the target inclination temperature becomes −1.

That is, the first PID control means 6 ₁
The average temperature is controlled, and each of the second to n-th PID control means 6 ₂
6 to 6n are for controlling the first to (n-1) -th gradient temperatures, respectively.

Next, the distribution means 7 will be described.

The distribution means 7 is provided with each PID control means 6₁
6n from each heater 1₁~ 1_n
The PID control means 6
₁Control of average temperature or slope temperature by each
The other PID control means 6 ₁~ 6n each flat
Eliminate interference with control of average or ramp temperature
It is to be distributed to.

[0059] For example, in the case of changing the average temperature by the first operational signal of the PID control means 6 _1, without gradient temperature is changed by the operation signal and by a second operation signal PID control means 6 ₂ When the first gradient temperature is changed, the average temperature and other gradient temperatures are not changed by the operation signal, and similarly, the control by the other PID control units is not affected by the operation signal of each PID control unit. It distributes.

The distribution by the distribution means 7 will be described in more detail.

Here, for simplicity, n = 2,
That is, there are two zones, and the first and second heaters 1 ₁ and 1 ₂ , the first and second temperature sensors 2 ₁ and 2 ₂ , and the first PID control means 6 ₁ for controlling the average temperature. FIG. 3 shows a case in which _second PID control means 62 for controlling the gradient temperature, which is the difference between the temperatures detected by both temperature sensors 2 ₁ and 2 ₂ , is provided.

FIG. 3 shows an example in which the present invention is applied to the control target 27 having the two-input and two-output interference described in the prior art of FIGS. 29 and 30. Reference numerals are assigned.

The average temperature / inclination temperature detecting means 5 comprises:
The feedback amounts PV1 and PV2 from the control target 27 corresponding to the detection outputs of the second temperature sensors 2 ₁ and 2 ₂ are shown in FIG.
As shown in FIG.
And outputs the average temperature Tav while the feedback amount PV corresponding to the detection output of both temperature sensors 2 ₁ and 2 _2.
1 and PV2 are subtracted by the subtractor 10 to output the gradient temperature Tt.

First PID control means 6₁Is the average temperature
Average temperature Tav from tilt temperature calculating means 5 and target average temperature
The average temperature reaches the target average temperature based on the
Output the operation signal (operation amount) Hav to the distribution means 7
And the second PID control means 6 _TwoIs the average temperature / gradient temperature
Control of slope temperature Tt and target slope temperature from calculation means 5
Based on the deviation, the slope temperature will be the target slope temperature.
An operation signal (operation amount) Ht is output to the distribution unit 7.

The distribution means 7 is composed of the PID control means 6 ₁ , 6 ₂
Operation signal (operation amount) Hav, the heaters in the allocation ratio as follows Ht _{1 1, 1 2} is distributed to.

FIG. 5 is a block diagram of a control system of the system shown in FIG. The first P controlling the average temperature
An operation amount Hav given from the ID controller _61, eliminating the interference in the allocation means 7, i.e., non-interference coefficient which is a coefficient for non-interacting (distribution ratio) k _1, first with k _2, the 2 of the heater ₁ 1, 1 with ₂ respectively distributed to the second
PID control means an operation amount Ht given from 6 _2, non-interacting factor (distribution ratio) k _3, k ₄ in the first, second heater 1
_1, 1 ₂ in allocated respectively, whereby each heater ₁ 1, 1 ₂ to the amount of heat H _1, H ₂ is to be given, respectively.

The amount of heat H ₁ given to the _first heater 11 is determined by the transfer coefficient (interference coefficient) l ₁ and the first temperature sensor 2.
While transmitted to _1, the second transmitted to the temperature sensor 2 ₂ by the transfer factor (interference coefficient) l _2, similarly, the amount of heat H ₂ given to the second heater 1 ₂ transfer coefficient (interference coefficient) l ₃ in the other hand transmitted to the first temperature sensor 2 _1, and transmitted to the transfer coefficient (interference coefficient) l temperature sensor 2 ₂ second at _4.

Then, the first temperature sensor 2₁Detected by
Detected temperature T₁And the second temperature sensor 2 _TwoDetected by
Temperature T_TwoThe average temperature Tav and the slope temperature Tt are calculated from
Issued and each PID control means 6₁, 6_TwoIs input to
A control loop is configured.

From the above, the average temperature Tav is expressed as follows.

Tav = (T ₁ + T ₂ ) / 2 = {(l ₁ · H ₁ + l ₃ · H ₂ ) + (l ₂ · H ₁ + l ₄ · H ₂ )} / 2 = ｛(l ₁ + l ₂ ) H ₁ + (l ₃ + l ₄ ) H ₂ ｝ / 2 = {(l ₁ + l ₂ ) (k ₁ · Hav + k ₃ · Ht) + (l ₃ + l ₄ ) (k ₂ · Hav + k ₄ · Ht)} / 2 = [{(l ₁ + l ₂ ) k ₁ + (l ₃ + l ₄ ) k ₂ ｝ Hav + ｛(l ₁ + l ₂ ) k ₃ + (l ₃ + l ₄ ) k ₄ ｝ Ht] / 2 The average temperature Tav is a function of only the manipulated variable Hav of the average temperature, and the term of Ht is set to 0 so as to eliminate the influence of the manipulated variable Ht of the gradient temperature, that is, to eliminate interference.

That is, (l ₁ + l ₂ ) · k ₃ + (l ₃ + l ₄ ) · k ₄ = 0 Therefore, k ₄ = − {(l ₁ + l ₂ ) / (l ₃ + l ₄ )}.
a k _3.

Similarly, the gradient temperature Tt is expressed as follows.

Tt = T ₁ −T ₂ = (l ₁ · H ₁ + l ₃ · H ₂ )-(l ₂ · H ₁ + l ₄ · H ₂ ) = (l ₁ -l ₂ ) H ₁ + (l ₃ −l ₄ ) H ₂ = (l ₁ −l ₂ ) (k ₁ .Hav + k ₃ .Ht) + (l ₃ −l ₄ ) (k ₂ .Hav + k ₄ .Ht) = ｛(l ₁ −l ₂ ) k _{1 + (l 3 -l 4)} k 2} Hav + {(l 1 -l 2) k 3 + (l 3 -l 4) k 4} Ht where gradient temperature Tt is the gradient temperature operation amount Ht In order to eliminate the influence of the manipulated variable Hav of the average temperature by using only the function, that is, to reduce the interference, the Hav term is set to 0.
And

That is, (l ₁ −l ₂ ) k ₁ + (l ₃ −l ₄ ) k ₂ = 0 Therefore, k ₂ = − {(l ₁ −l ₂ ) / (l ₃ −l ₄ )}
k ₁ to become.

From the above, the average temperature is controlled without affecting the gradient temperature, and the gradient temperature is controlled without affecting the average temperature, that is, the interference between the average temperature and the gradient temperature is eliminated. to perform decoupling control, the non-interference coefficients may be apportioned (distribution ratio) k ₁ to k _4, in order to calculate the non-interacting factor (distribution ratio) k ₁ to k ₄ are the heater 1 ₁ of heat is first 1, second temperature sensors 2 _1, 2 ₂ to the transmitted transfer coefficient (interference coefficient) l _1, l ₂ and the second heat quantity of the heater 1 ₂ first, the second It is necessary to know the transfer coefficients (interference coefficients) l ₃ and l ₄ transmitted to the temperature sensors 2 ₁ and 2 ₂ .

The decoupling coefficients (distribution ratios) k _{1 to} k _1
4 can be handled by the gain of PID control if the ratio between k ₁ and k ₂ and the ratio between k ₃ and k ₄ are known, so the absolute value is not necessarily required.

The transfer coefficients (interference coefficients) l _{1 to} l ₄ can be obtained as follows. That is, only one heater is changed and the other heaters are fixed at a constant value, for example,
The ratio of the change amount of each temperature sensor to the change amount of the heater is used as the transfer coefficient while the switch is kept on or off.

[0078] For example, in the state of the second heater 2 ₂ off, first heater 1 _1, with variation at a certain temperature amplitude, the first temperature sensor 2 ₁ second, 2 ₂ The transfer coefficients l ₁ and l ₂ can be measured depending on how much the temperature amplitude fluctuates in the detected temperature. For example, when the heater fluctuates at the temperature amplitude 1, the temperature amplitude of the temperature sensor becomes 1
If 0, the transfer coefficient is 10 (= 10/1).

Here, the distribution using the decoupling coefficient (distribution ratio) in the distribution means 7 of FIG. 3 will be described more specifically. The characteristic of the control target 27 is shown in FIG. 30 described above, and from this characteristic, the transfer coefficient is l ₁ = 1, l ₂ =
0.9, l ₃ = 0.9, l ₄ = 1.

Therefore, when substituting into the above equation of the decoupling coefficient, k ₄ = − ｛(l ₁ + l ₂ ) / (l ₃ + l ₄ )｝ k ₃ = − ｛(1 + 0.9) / (0.9. 9 + 1)｝ k ₃ = −k ₃ and k ₂ = − ｛(l ₁ −l ₂ ) / (l ₃ −l ₄ )｝ k ₁ = − ｛(1−0.9) / (0.9− 1)｝ k ₁ = k ₁ .

Therefore, suppose that the total amount of heat distributed to each heater is equal to Hav, that is, k ₁ +
k ₂ = 1, and for simplicity, k ₃
= 1 is added.

As a result, k ₂ = k ₁ = 1/2 and k ₄ = −k ₃ = −1, and the distribution ratio (coupling coefficient) is determined.

[0083] That is, as shown in FIG. 5, the operation amount Hav average temperature, 1/2 by the heaters ₁ 1, 1 ₂ allocated to the operation amount Ht of gradient temperature, the first heater 1 ₁ In
As it is, the second heater 1 _2, may be distributed by changing the code.

Here, the distribution ratio (decoupling coefficient) can also be obtained as follows.

That is, based on the above-mentioned mode conversion matrix Gm and the above-mentioned transfer coefficient (interference coefficient) matrix P, a distribution ratio (decoupling coefficient) matrix (hereinafter also referred to as “pre-compensation matrix”) G
c can also be obtained as an inverse matrix as follows.

Gc = (Gm · P) ^{−1 When} applied to this embodiment, a matrix P of a transfer coefficient (interference coefficient) which is a characteristic of a controlled object at a certain time is expressed by

[0087]

(Equation 3)

Then, the pre-compensation matrix Gc, which is a matrix of the distribution ratio (decoupling coefficient), is

[0089]

(Equation 4)

As a check, it is calculated whether or not Gm · P · Gc = 1.

[0091]

(Equation 5)

In this embodiment, the distribution ratio (decoupling coefficient) is calculated using the transfer coefficient. However, as another embodiment of the present invention, instead of the transfer coefficient, a frequency characteristic is also represented. You may make it calculate using a transfer function.

In the system of FIG. 3, the distribution means 7
As shown in the figure, the average temperature operation signal (operation amount) Ha
v is attenuated by 減 衰 in each of the attenuators 11 and 12, and distributed to the adder 13 and the subtractor 14, respectively. The operation signal (operation amount) Ht of the gradient temperature is supplied to the adder 13 and the subtractor 14. are respectively allocated, the heater 1 ₁ output H ₁ is the first adder 13, the output of H ₂ subtracter 14 is applied to the second heater 1 _2.

[0094] According to the allocation means 7, in the case of changing the average temperature by the operation amount Hav average temperature, since the operation amount is distributed equally to each heater 1 _1, 1 _2, influence the gradient temperature It is possible to change only the average temperature without, that is, without interference. Further, in the case of changing the gradient temperature by the operation amount Ht slope temperature is one of the heater 1 _1, while the operation amount is given in 1x, to the other heater 1 _2, given by -1 times Therefore, only the gradient temperature can be changed without changing the total amount of heat applied to both heaters, that is, without affecting the average temperature.

FIG. 7 shows the average temperature Tav from the average temperature / inclination temperature calculation means 5 when the _first PID control means 61 performs auto-tuning in the system of FIG.
(Broken line), the manipulated variable Hav of the average temperature from the _first PID control means 61 (solid line), the average temperature / inclination temperature calculation means 5
And the operation amount Ht (single-dot chain line) of the inclination temperature from the _second PID control means 62 is shown on the scope, and the operation amount H of the average temperature is shown.
There is a limit cycle in which av is turned on and off, and parameters of PID control can be determined using the cycle and amplitude of the average temperature Tav. The average temperature Ta
v, the slope temperature Tt, the manipulated variable Hav of the average temperature, and the manipulated variable Ht of the slope temperature are the same as those of the conventional example of FIGS. 28 and 31 described above.
1, PV2, MV1, and MV2.

The PID of the first PID control means 6 ₁
After the control parameters are determined, the parameters are set, and then the PID control parameters are determined by performing automatic tuning of the _second PID control means 62 for controlling the tilt temperature.

As described above, by controlling the average temperature and the gradient temperature as control amounts, it becomes possible to perform control without interference, to perform auto-tuning for determining the parameters of the PID control, and to determine the optimal control parameters. By setting, desired control characteristics can be obtained.

In the normal control after the parameters of the PID control are set as described above, control is performed so that the average temperature becomes the target average temperature and the gradient temperature becomes the target gradient temperature.

Next, the results of a simulation between this embodiment and a conventional example will be described below. In this simulation, modeling of the control target as described below was performed. That is, as the simplest example of the thermal interference system, the heater 1 ₁ two sets of 8, 1 ₂ and the temperature sensor 2 _1, 2 ₂
And a heat treatment apparatus in which a heat conductor 50 is connected between them. The control purpose is to equalize the temperatures at the two points at an arbitrary set temperature. FIG. 9 shows an electrical equivalent circuit of the control target. R ₁ and R ₂ are the thermal resistance from the temperature sensor to the surrounding air, and C ₁ and C ₂ are the heat capacities near the temperature sensor.

[0100] input of the control object is a two heaters heat, a portion of the heat p ₁ of the heater 1 ₁ transmitted a heat conductor 50, the interference temperature theta ₂ of the temperature sensor 2 ₂ thermal resistance R ₃ and, a portion of the heat p ₂ of the heater 1 ₂ is likewise interfere with the thermal resistance R ₃ on the temperature theta ₁ of the temperature sensor 2 _1. A part of the thermal energy of the heat p ₂ is conducted to the machine body heat treatment apparatus in thermal resistance R ₄ is fixed. However, since the heat capacity of the machine body was very large, it was approximated that the heat capacity coincided with the ambient temperature.

The parameter of the equivalent circuit to be controlled is R ₁
= R ₂ = 10 [° C./W], R ₃ = 1 [° C./W], R ₄ = 0.
2 [° C./W] and C ₁ = C ₂ = 10 [J / ° C.]. The disturbance was in the form of a step of 100 W, and was applied under the same conditions as in the conventional example and this embodiment.

A conventional PI using the parameters in Table 1 below
FIG. 10 shows the response waveform of the D control, and FIG. 11 shows the response waveform of this embodiment according to the parameters shown in Table 2 below.

[0103]

[Table 1]

[0104]

[Table 2]

When comparing FIG. 10 and FIG. 11, a temperature difference of 2 ° C. is generated by the conventional control method. In this embodiment, the temperature difference between the two sensors is 0.8 ° C. It can be seen that it has improved up to.

The reason why such a difference in characteristics can be produced is as follows.
In this embodiment, the PI and the average temperature are independent of each other.
The point is that the D parameter can be set. In this example, Table 2
The proportional gain Kp of the gradient temperature control is set to a value larger than the proportional gain Kp of the average temperature control so as to give a difference to the proportional gain Kp and give priority to the convergence of the gradient temperature over the average temperature as shown in FIG. As a result, high-precision temperature uniformization can be expected despite simple PID control parameter settings.

FIGS. 12 to 15 show comparison results of the target value response and the disturbance response between this embodiment and the conventional example. Note that here, CHR (Chien, Hrones and Re
In the swick) adjustment rule, no target value response overshoot was used for average temperature control, and a disturbance response overshoot of 20% was used for gradient temperature control.

FIGS. 12 and 13 show the waveforms of the target value response and the disturbance response of this embodiment, and FIGS. 14 and 15 show the waveforms of the target value response and the disturbance response of the conventional example.

In the target value response of the prior art shown in FIG. 14, the settling time was as long as 29 seconds, and overshoot was recognized. However, in the target value response of this embodiment, as shown in FIG. It was as short as 9 seconds and no overshoot was observed.

Further, in the disturbance response of the conventional example of FIG. 15, the settling time was as long as 32 seconds, and overshoot was slightly recognized. On the other hand, in the disturbance response of this embodiment, FIG.
As shown in FIG. 3, the settling time was as short as 6 seconds, and no overshoot was observed.

That is, in this embodiment, the average temperature control performs weak and slow control, and the gradient temperature control performs strong and fast control. Therefore, in both the target value response and the disturbance response, the overshoot occurs. The settling time was short and satisfactory.

In the above example, for simplicity, n = 2
However, the present invention can be similarly applied to the case where the number of zones is three, that is, the case where the number of heaters, temperature sensors and PID control means is three (n = 3).

That is, as shown in the block diagram of FIG. 16 corresponding to FIG.
A ₁ to 1 _3, first to the corresponding individually to each of the heater ₁ 1 to 1 ₃
The third temperature sensors 21 to 23 are respectively disposed in the _first to _third zones, the first zone and the second zone are adjacent to each other, and the second zone and the third zone are arranged. the zone and are adjacent, for simplicity, assume that only the interference between adjacent zones, transfer coefficient from the first heater 1 ₁ to the second temperature sensor 2 ₂ (interference coefficient) l ₁ , the second heater 1
₂ first, third temperature sensor 2 _1, transfer factor to 2 ₃ (interference coefficient) l _2, l _3, transfer coefficient from the third heater 1 ₃ to the second temperature sensor 2 ₂ (interference the coefficient) and l _4, opposite transfer coefficient from the first heater 1 ₁ such first temperature sensors 2 ₁ (interference coefficient) is 1.0.

A first PID for controlling an average temperature for a decoupling coefficient (allocation ratio) for eliminating interference.
Control means 6 _first operation amount Hav second, third heater 1 _2,
K ₁ the non-interacting factor (distribution ratio) for distributing to 1 _3, k
_2, non-interference coefficients for distributing the operation amount Ht ₁ second PID control means 6 ₂ for controlling the first gradient temperature Tt ₁ in first, third heater 1 _1, 1 ₃ (distribution ratio ) To k ₃ and k ₄ , the second
The third PID control means 6 ₃ operation amount Ht2 the first, second heater ₁ 1, 1 decoupling factor to allocate ₂ to the (distribution ratio) k ₅ for controlling the gradient temperature Tt _2, and k _6, facing the non-interference coefficients from the first PID control means 6 ₁ like the first heater 1 ₁ to 1.0. Note that, in this example, the first inclination temperature Tt1 is equal to the second and third temperature sensors 2 ₂ ,
2 ₃ average detected temperature of the detected temperature T _2, T ₃ and has a difference between the first and the detected temperature T ₁ of the temperature sensor 2 _1, and the second
Gradient temperature Tt ₂ of the second temperature sensor 2 ₂ detected temperature T
₂ and the difference between the detected temperature T _{3 of the third} temperature sensor 23.

At this time, the average temperature Tav is expressed as follows.

Tav = (T ₁ + T ₂ + T ₃ ) / 3 = ｛(H ₁ + l ₂ · H ₂ ) + (l ₁ · H ₁ + H ₂ + l ₄ · H ₃ ) + (l ₃ · H ₂ + H ₃₎ )｝ / 3 = ｛(1 + l ₁ ) H ₁ + (1 + l ₂ + l ₃ ) H ₂ + (1 + l ₄ ) H ₃ ｝ / 3 = ｛(1 + l ₁ ) (Hav + k ₃ · Ht ₁ + k ₅ · Ht ₂ ) + (1 + l ₂ + l ₃ ) (k ₁ · Hav + Ht ₁ + k ₆ · Ht ₂ ) + (1 + l ₄ ) (k ₂ · Hav + k ₄ · Ht ₁ + Ht ₂ )｝ / 3 = [｛(1 + l ₁ ) + (1 + l ₂ + l ₃ ) k ₁ + (1 + l ₄ ) k ₂ ｝ Hav + ｛(1 + l ₁ ) k ₃ + (1 + l ₂ + l ₃ ) + (1 + l ₄ ) k ₄ ｝ Ht ₁ + ｛(1 + l ₁ ) k ₅ + (1 + l _{2) + l 3) k 6 + (} 1 + l 4)} Ht 2 ] / 3, where the average temperature Tav is a function of only the operation amount Hav average temperature, the operation of the gradient temperature amounts Ht _1, Ht ₂ To eliminate the influence of the manipulated variable, i.e., in order to non-interference, and 0 to the section Ht _1, Ht _2.

That is, (1 + l ₁ ) k ₃ + (1 + l ₂ +
_{l 3) + (1 + l} 4) k 4 = 0 (1 + l 1) k 5 + (1 + l 2 + l 3) k 6 + (1 + l 4) =
It becomes 0.

This will be simplified as follows.

La + lb · k ₃ + lc · k ₄ = 0 ld + le · k ₅ + lf · k ₆ = 0 In the same manner as for the first slope temperature Tt ₁ , the manipulated variable Ht ₁ of the first slope temperature is also set. By applying the condition that the operation amount Hav of the average temperature and the operation amount Ht2 of the _second gradient temperature are not affected by only the function, the following equation can be obtained.

Lg + lh · k ₁ + li · k ₂ = 0... Lj + l _k · k ₅ + l _l · k ₆ = 0 Also, the following equation is similarly obtained for the second gradient temperature Tt ₂ .

Lm + ln · k ₁ + lo · k ₂ = 0 lp + lq · k ₃ + lr · k ₄ = 0... Transfer coefficients l _{1 to} l ₄ , and therefore, la to lr are n = 2
Since it is determined in the same manner as in the non-interacting factor k ₁
As a result, the following _six equations, in which the unknowns are set as k ₆ , are obtained, and by solving these equations, the decoupling coefficients (allocation ratios) k _{1 to} k ₆ to be allocated by the allocation unit are obtained. become.

For example, if it is determined by a determinant, the following is obtained.

[0123]

(Equation 6)

[0124]

(Equation 7)

As described above, the present invention can be similarly applied to a control system with n = 3 or more.

The pre-compensation matrix Gc, which is a matrix of the distribution ratio (decoupling coefficient), can be obtained from the mode conversion matrix Gm and the matrix P of the transfer coefficient (interference coefficient) as described above. the first PID controller 6 ₁ first heater 1 ₁
Can be obtained including the opposite decoupling coefficient. Here, a matrix P of a transfer coefficient (interference coefficient) which is a characteristic of the control target at a certain time is represented by

[0127]

(Equation 8)

Assuming that l1 = l2 = l3 = l4 = 0.9,

[0129]

(Equation 9)

The prefix compensation matrix Gc is

[0131]

(Equation 10)

As a check, it is calculated whether or not Gm · P · Gc = 1.

[0133]

[Equation 11]

FIG. 17 is a block diagram of a temperature controller according to another embodiment of the present invention. Parts corresponding to the embodiment of FIG. 2 described above are denoted by the same reference numerals. In FIG. 17, the target average temperature SV average or the target gradient temperatures SVg1 to SVg-1 and the average temperature PV calculated by the average temperature / gradient temperature calculating means (mode converter) 5 are shown.
The adder 26 ₁ ~ 26 _n for outputting a control deviation between the average or gradient temperature PVg1~PVgn-1, shows the outside of the PID control means 6 ₁ to 6 _n.

In this embodiment, the PI of the average temperature control is
A limiter 80 for limiting the operation amount of the D control unit ₆₁ (operation signal) is provided. In this way, when a large disturbance that saturates the operation amount is applied to the whole, for example, when a wafer is mounted on a heat treatment board, the temperature uniformity control performance is improved. Can be done.

The reason will be described in detail below. For example, when there is a saturation of the operation amount during a disturbance response of in-plane temperature uniformity in which a wafer is placed as a disturbance on the heat treatment board, the average temperature control and the gradient temperature control are traded off.

As a preparation for explanation, in the case of a two-input / output system,
The set operation amount MV will be described with reference to FIG. Signal signal outputted from the average for the PID controller ₆₁ is outputted average MV, from the tilt PID controller 6 ₂ is inclined MV. The average MV and the slope MV pass through the pre-compensator (distribution means) 7 and furthermore, the saturation limit 81
_1, 81 to pass through a _2, a MV of each ch the ch1MV and Ch2MV. The pre-compensator 7 is composed of 1 and −1 as shown in FIG. 18 for simplicity. Therefore, ch1MV = average MV−slope MV, and c
h2MV = mean MV + slope MV. c
Since each MV cannot output 0% or less and 100% or more for each h, it is limited.

The cause of the trade-off is that, as shown in FIG. 19, when the average MV is already saturated to 100%,
Even if the slope MV outputs a value for controlling the temperature difference to be zero, it is buried in the saturation of the MV for each channel,
It does not work.

Conversely, the temperature difference in which the gradient MV is the control amount is set to 0
If it is desired to work such that the MV of each channel does not saturate at the average MV as shown in FIG. Then, the value of the slope MV is reflected on the MV for each channel, and the temperature difference quickly converges to zero. That is, the uniformization control works well. Instead, the MV for each channel becomes smaller than 100%, so that the average temperature convergence time is prolonged. This is a trade-off.

Therefore, in this embodiment, as shown in FIG. 17, the upper limit of the operation amount of the average temperature control is suppressed by the limiter 80, so that the PID control means 6 _{1 to} 6 are controlled.
_When a large disturbance such that the operation amount from _n-1 is saturated is received, the inclination temperature control appears in a table without being hidden by the saturation of the operation amount for each channel and enables uniform operation.

FIG. 21 is a block diagram of another embodiment of the present invention.
The same reference numerals are given.

In this embodiment, limiters 82 ₂ to 82 _n are provided to limit the operation amount of the inclination temperature control, not the operation amount of the average temperature control.

In this embodiment, when a disturbance that is partially offset, but not entirely, is applied, for example, when a low-temperature object comes into contact with a part of a hot plate, priority is given to the gradient temperature control. Therefore, the operation amount of the inclination temperature control is suppressed and the convergence of the average temperature is accelerated.

As still another embodiment of the present invention, as shown in FIG. 22, limiters 80 and 82 for limiting the operation amounts of both the average temperature control and the inclination temperature control.
_{2 to} 82 _n may be provided.

In the above-described embodiment, the upper limit of the operation amount is limited by the limiter. However, as another embodiment of the present invention, the lower limit or both may be limited.

In each of the above embodiments, each PID control means controls the average temperature to the target average temperature or the gradient temperature to the target gradient temperature, respectively. And the target ramp temperature are
The user sets the target temperature, but it is difficult for the user who has set the target temperature for each channel in the related art to set the target average temperature and the target inclination temperature.

Therefore, as shown in FIG.
A mode converter 5 'for calculating a target average temperature and a target inclination temperature from each target temperature SP may be provided. In FIG. 23, portions corresponding to FIG. 3 described above are denoted by the same reference numerals. This mode converter 5 '
The configuration is the same as that of the mode converter 5 that calculates the average temperature and the inclination temperature from the detected temperatures of the temperature sensors of the respective channels, which are the feedback amounts from the control target 27.

As described above, by adding the mode converter 5 ', the user can set the target temperature SP for each channel in the same manner as in the related art without considering the average temperature and the gradient temperature.

Further, as another embodiment of the present invention,
As shown in FIG. 24, the temperature deviation between the detected temperature of the temperature sensor of each channel, which is the feedback amount from the control target 27, and the target temperature SP is obtained, and the average deviation, which is the control deviation, is obtained from the temperature deviation of each channel. A mode converter 5 ″ for calculating the deviation and the inclination temperature deviation may be provided. According to this configuration, the user can set the target temperature of each channel in the same manner as in the related art without considering the average temperature and the gradient temperature, and can reduce the number of the mode converters 5 ″ to one. The capacity can be reduced and the processing can be simplified.

That is, in each of the above-described embodiments, the mode converters 5, 5 'convert the temperatures detected from the plurality of temperature sensors into the average temperature and the gradient temperature. The mode converter 5 ″ of the embodiment converts a temperature deviation between the detected temperatures from the plurality of temperature sensors and the target temperature into an average temperature deviation that is a deviation between the detected average temperature and the target average temperature. Is converted into a gradient temperature deviation which is a deviation between the detected gradient temperature and the target gradient temperature.

That is, in each of the above embodiments, the control deviation is obtained after converting the detected temperature into the average temperature and the gradient temperature, whereas in this embodiment, the temperature deviation between the detected temperature and the target temperature is obtained. And converts the temperature deviation into an average temperature deviation and a gradient temperature deviation, which are control deviations.

As another embodiment of the present invention, the limit value of the limiter may be variably adjusted.

As another embodiment of the present invention, instead of the average temperature, for example, control may be performed using the temperature of the central zone as the representative temperature, and the representative temperature and the gradient temperature as control amounts.

In the above embodiment, only one average temperature is used as the average temperature. However, as another embodiment of the present invention, for example, each average temperature of each group divided into a plurality of groups, that is, Alternatively, a plurality of average temperatures may be used.

Although the above embodiment has been described by applying to PID control, the present invention is not limited to PID control but can be applied to other control methods such as on / off control, proportional control, and integral control. is there.

The heat treatment apparatus of the present invention is not limited to a thermal oxidation apparatus, but is also applicable to a diffusion furnace or a CVD apparatus, for example, as shown in FIG. 25, for temperature control of a heat treatment board in a single-wafer CVD apparatus. You can do it. In FIG. 25, the heat treatment board 61 on which the wafer 60 is placed is divided concentrically into an outer circle portion 62, an intermediate portion 63, and a central portion 64, and heaters 65 to 65 individually corresponding to the respective portions. A temperature control 67 is provided for each zone. Further, the heat treatment apparatus of the present invention can be applied to temperature control of a cylinder portion of an injection molding machine or temperature control of a heater base of a packaging machine.

In the above embodiment, the description has been given of the case where the present invention is applied to temperature control using a heating means such as a heater, but it is needless to say that the present invention may be applied to temperature control using a Peltier element or a cooler. Further, the present invention may be applied to temperature control using both a heating unit and a cooling unit.

Further, the present invention is not limited to temperature control, but can be applied to control of other physical states such as pressure, flow rate, speed or liquid level.

[0159]

As described above, according to the present invention, it is possible to reduce the interference and to set the optimal control parameters in the control of the control object having the interference.

In addition, control in which other state control is prioritized over state control in which the operation signal is restricted by the restriction means, for example,
Temperature control can be performed with priority given to temperature control based on the inclination temperature over temperature control based on the average temperature, and appropriate control can be performed according to the application, characteristics of the control target, and the like.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a temperature control system according to one embodiment of the present invention.

FIG. 2 is a block diagram of the temperature controller of FIG. 1;

FIG. 3 shows a configuration in which a temperature sensor, a heater, and PID control means are 2
FIG.

FIG. 4 is a block diagram of an average temperature / inclination temperature calculation means 5 of FIG. 3;

FIG. 5 is a block diagram of a control system of FIG. 3;

FIG. 6 is a block diagram of a distribution unit of FIG. 3;

FIG. 7 is a waveform chart at the time of auto tuning of the system of FIG. 3;

FIG. 8 is a diagram illustrating a model of a control target.

FIG. 9 is an equivalent circuit diagram of a control target.

FIG. 10 is a diagram showing a response waveform of a conventional example.

FIG. 11 is a diagram showing a response waveform according to the embodiment.

FIG. 12 is a diagram showing a target value response waveform according to the embodiment.

FIG. 13 is a diagram showing a disturbance response waveform according to the embodiment.

FIG. 14 is a diagram showing a target value response waveform of a conventional example.

FIG. 15 is a diagram showing a disturbance response waveform of a conventional example.

FIG. 16 is a block diagram of a control system when there are three zones.

FIG. 17 is a block diagram of another embodiment of the present invention.

FIG. 18 is a configuration diagram for explaining an operation amount.

FIG. 19 is a diagram showing a change in the operation amount when the tilt temperature control does not work.

FIG. 20 is a diagram illustrating a change in the operation amount when the tilt temperature control is activated.

FIG. 21 is a block diagram of still another embodiment of the present invention.

FIG. 22 is a block diagram of another embodiment of the present invention.

FIG. 23 is a block diagram of still another embodiment of the present invention.

FIG. 24 is a block diagram of another embodiment of the present invention.

FIG. 25 is a view showing another heat treatment apparatus.

FIG. 26 is a diagram showing a configuration of a thermal oxidation device.

FIG. 27 is a configuration diagram of a system that controls two control targets without interference.

FIG. 28 is a waveform chart at the time of auto-tuning of the system of FIG. 27;

FIG. 29 is a configuration diagram of a system that controls a control target having interference.

30 is a diagram showing a configuration of a control target in FIG. 29.

31 is a waveform chart at the time of auto tuning of the system of FIG. 29.

[Explanation of symbols]

1 ₀ 1n heater 2 ₀ to 2n temperature sensor 3 the controlled object 4 temperature controller 5 average temperature-gradient temperature calculating means 6 ₁ ~6n PID controller 7 allocation means 15 the heater plate 18 thermal oxidizer 80, 82 ₂ to 82 _n limiter

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Takeshi Wakabayashi 10th Hanazono Dodocho, Ukyo-ku, Kyoto, Kyoto O Inside the Murron Co., Ltd. (72) Taiichi Kitamura 10th Hanazono Dodocho, Ukyo-ku, Kyoto, Kyoto F-term in Muron Corporation (reference)

Claims (6)

[Claims] A converting means for converting information from a plurality of detecting means for respectively detecting a physical state of a control object into information indicating a gradient of the physical state and converting the information into information indicating a representative state of the physical state; A plurality of state control means to which each information from the conversion means is individually given; an operation signal from each state control means, a plurality of operation means, control by each state control means, other state control Distributing means for distributing so as to eliminate or reduce the influence on the control by the means, and limiting means provided before the distributing means and restricting an operation signal from at least one state control means. A control device characterized by the above-mentioned. 2. A deviation between information from a plurality of detecting means for respectively detecting a physical state of a control target and a plurality of target information individually corresponding to the plurality of detecting means, the information indicating a gradient of the physical state. Conversion means for converting into a deviation of the information indicating the representative state of the physical state, and a deviation of the information indicating the gradient or the deviation of the information indicating the representative state from the conversion means as a control deviation. A plurality of state control means each outputting a signal, an operation signal from each of the state control means, a plurality of operation means, the control by each state control means eliminates the influence on the control by other state control means or Distributing means for distributing the signal so as to be reduced, and limiting means provided before the distributing means and restricting an operation signal from at least one of the state control means. Control device and wherein the door. 3. A converting means for converting detected temperatures obtained from a plurality of temperature detecting means for detecting a temperature of a control object into a gradient temperature based on the plurality of detected temperatures, and converting the detected temperature into a representative representative temperature. A plurality of temperature control units each outputting an operation signal using the tilt temperature or the representative temperature from the conversion unit as a control amount; and a plurality of operation signals from each of the temperature control units for heating (or cooling) the control target. A allocating means for allocating the heating (or cooling) means so that the control by each temperature control means eliminates or reduces the influence on the control by the other temperature control means; and A limiter for limiting an operation signal from one of the temperature control means. 4. A difference between a detected temperature obtained from a plurality of temperature detecting means for respectively detecting a temperature of a control target and a plurality of target temperatures individually corresponding to the plurality of temperature detecting means, is calculated as a deviation of a slope temperature. A conversion means for converting into a representative representative temperature deviation, and a plurality of temperature control means each outputting an operation signal as the deviation of the slope temperature or the deviation of the representative temperature from the conversion means as a control deviation. An operation signal from each of the temperature control means, to a plurality of operation means, distribution means for distributing the control by each temperature control means so as to eliminate or reduce the influence on the control by other temperature control means, A limiter provided before the distribution unit and limiting an operation signal from at least one of the temperature control units. 5. The method according to claim 1, wherein the representative temperature is an average temperature based on a plurality of detected temperatures, and at least one of the temperature control means outputs an operation signal using the average temperature as a control amount or a deviation of the average temperature. The temperature controller according to claim 3, wherein the temperature controller is a temperature control unit. 6. The temperature controller according to claim 3, a heat treatment furnace or a heat treatment plate as a control object, and heating (or cooling) the heat treatment furnace or the heat treatment plate.
And a plurality of temperature detecting means for detecting a temperature of the heat treatment furnace or the heat treatment board.