JP2001306103A - Control unit, thermoregulator and device for heat treatment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce interference in controlling the object of control which receives the interference. SOLUTION: By installing the PID controllers 62' and 63', which output manipulation signals to the manipulating means of one channel based on the deviation of the other channel in addition to the PID controllers 61' and 64' which correspond to each channel, respectively, it is possible to remove or reduce the influence of one channel control on the other channel control, and further the control based on an inclined temperature and an average temperature is possible.

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. 38, 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).

[0008] First, as an example of possible auto-tuning normally, the case of controlling the first, second control object 24 _1, 24 ₂ without interference independence shown in Figure 39. 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. 40 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. 41, a case will be described in which independent control is performed on a control target 27 having two-input (MV1, MV2) and two-output (PV1, PV2) interference.

As shown in FIG. 42, the controlled object 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 as 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.

The present invention has been made in view of the above points, and has as its object to reduce the interference of a controlled object having interference.

[0017]

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

That is, the control device of the present invention is based on each deviation between a plurality of pieces of detection information from a plurality of detection means for respectively detecting a physical state of a control target and a plurality of target information.
A control device comprising: a plurality of state control means for respectively outputting operation signals to a plurality of operation means individually corresponding to the detection means, wherein the control device includes: At least one decoupling control unit that outputs an operation signal to an operation unit different from the operation unit corresponding to the detection unit is provided.

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.

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

The decoupling control means controls so as to eliminate or reduce the influence of the control by one state control means on the control by another state control means.

According to the control device of the present invention, an operation signal is output to each of the plurality of operation means individually corresponding to the detection means based on each deviation between the plurality of detection information and the plurality of target information. A plurality of state control means, that is, a state control means individually corresponding to each of a plurality of channels, and a non-interference output operation signal to an operation means of another channel based on a deviation of a certain channel. Since the conversion control means is provided, the influence of the control by the state control means of each channel on the control of another channel is reduced.

In one embodiment of the present invention, the plurality of state control means and the non-interference control means determine each deviation between the plurality of detection information and the plurality of target information by using a gradient of the physical state of a control object. A conversion means for converting the information indicating the physical state into a deviation of information representing the representative state, and a deviation of the information indicating the gradient or the deviation of the information indicating the representative state from the conversion means. A plurality of state control means each outputting an operation signal, and an operation signal from each state control means, a plurality of operation means,
It has a function as distribution means for distributing the control by each state control means so as to eliminate or reduce the influence on the control by the other state control means.

Here, the gradient of the physical state is a temperature gradient,
A gradient of various physical quantities such as a pressure gradient, a flow gradient, and a velocity gradient.

Furthermore, 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), etc. Say.

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. 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.

[0028] The temperature controller of the present invention is provided for each of the temperature detecting means based on each temperature deviation between a plurality of detected temperatures from a plurality of temperature detecting means for respectively detecting a temperature of a control object and a plurality of target temperatures. A temperature controller comprising a plurality of temperature control means for respectively outputting operation signals to a plurality of heating (or cooling) means for heating (or cooling) said control target in a corresponding manner, wherein said temperature controller comprises: Heating (or cooling) different from heating (or cooling) means corresponding to the certain temperature detecting means, based on the temperature deviation corresponding to the means;
Decoupling control means for outputting an operation signal to the means,
At least one is provided.

Here, the temperature controller of the present invention comprises a plurality of heating (or cooling) means individually corresponding to the temperature detecting means based on each temperature deviation between a plurality of detected temperatures and a plurality of target temperatures. It controls a plurality of channels including a plurality of temperature control means each outputting an operation signal to the so-called temperature controller of so-called multi-point control or a temperature controller of single-point control. It is good also as a temperature controller of the present invention by combining a plurality. That is, the temperature controller of the present invention also includes a configuration in which a plurality of single-point control temperature controllers are combined.

According to the present invention, an operation signal is sent to a plurality of heating (or cooling) means individually corresponding to the temperature detecting means based on each temperature deviation between the plurality of detected temperatures and the plurality of target temperatures. A plurality of temperature control means respectively outputting,
That is, in addition to temperature control means individually corresponding to each of a plurality of channels, non-interference control for outputting an operation signal to a heating (or cooling) means of another channel based on a deviation of a certain channel. Since the means is provided, the influence of the control by the temperature control means of each channel on the control of another channel is reduced.

In one embodiment of the present invention, the plurality of temperature control means and the decoupling control means convert each temperature deviation between the plurality of detected temperatures and the plurality of target temperatures into a deviation of a slope temperature. Along with, a converting means for converting to a deviation of the representative temperature, a plurality of temperature control means for respectively outputting an operation signal based on the deviation of the gradient temperature or the deviation of the representative temperature from the converting means, and To the plurality of heating (or cooling) means for heating (or cooling) the controlled object so that the control by each temperature control means has no or little effect on the control by other temperature control means. It has a function as distribution means for distributing.

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 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. 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.

[0033] In another embodiment of the present invention, the representative temperature is an average temperature based on a plurality of detected temperatures.

According to the present invention, temperature control is performed using the average temperature and the gradient temperature as control amounts. For example, when temperature control is performed using the detected temperature of each zone as a control amount by dividing the control target into a plurality of zones. , The degree of interference between zones can be reduced. Further, for example, when the control target is divided into a plurality of zones and the temperature detecting means is arranged in each zone, the temperature detected by the temperature detecting means in a certain zone and the temperature detected by the temperature detecting means in an adjacent zone are detected. The slope temperature, which is the difference from the detected temperature, can be used as the control amount,
It is possible to perform control with a temperature difference for each zone.

In a preferred embodiment of the present invention, a disconnection detecting means for detecting a disconnection of the detection signal lines of the plurality of temperature detecting means is provided, and the disconnection detecting means compares each detected temperature with the average temperature. A disconnection is detected based on a comparison between the inclination temperature and a threshold.

According to the present invention, since the disconnection of the detection signal line of the temperature detecting means can be detected, when the disconnection occurs, it can be notified and an appropriate measure can be taken immediately.

In another embodiment of the present invention, the replacing means for replacing the detection output of the temperature detecting means in which the disconnection is detected with the average temperature of a plurality of detected temperatures or the detected temperature of another temperature detecting means arranged in close proximity. It has.

According to the present invention, the detection output of the temperature detecting means in which the disconnection is detected is replaced with the average temperature or the detected temperature of another temperature detecting means arranged close to the control means. The temperature can be controlled to a state close to a desired state.

In still another embodiment of the present invention,
The temperature detecting means is an infrared camera.

According to the present invention, since an infrared camera is used as the temperature detecting means, the temperature can be detected in a non-contact manner and the detection point can be easily changed.

The heat treatment apparatus of the present invention comprises a temperature controller of the present invention, a heat treatment furnace or a heat treatment board as a control object, and a plurality of heating (or cooling) means for heating (or cooling) the heat treatment furnace or the heat treatment board. 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.

[0043]

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. 38 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.

Hereinafter, prior to the description of a specific embodiment of the present invention, the function of the temperature controller of the present invention will be described in detail.

[0049] Figure 2 is a functional block diagram of the temperature controller 4 of Figure 1, the temperature controller 4 of this embodiment, the average temperature and the detected temperature of the temperature detected by the plurality of temperature sensors 2 ₁ to 2n Average temperature / inclination temperature calculating means (hereinafter also referred to as “mode converter”) 5 for calculating the inclination temperature based on the above-mentioned temperature, and the average temperature or each inclination temperature calculated by the calculation means 5 are input. each heater constituting the PID control means 6 ₁ ～6N as a plurality of temperature control means, the heating means at a predetermined distribution ratio as described below an operation signal from the PID control means 6 ₁ ~6n (manipulated variable) 1 Distribution means (hereinafter, also referred to as a "pre-compensator") 7 for distributing the data to _{1 to} 1n. Mean temperature / inclination temperature calculating means 5, PID
The control means 61 _to 6n and the distribution means 7 are constituted by, for example, a microcomputer.

Conventionally, as shown in FIG. 38 described above, the temperature is detected for each zone and the corresponding heater is individually controlled. However, in this embodiment, in order to eliminate interference, 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.

[0051] 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. .

[0052] 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.

[0055]

(Equation 1)

[0056] 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.

The gradient temperature is not limited to this embodiment, but may be, for example, the following mode 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.

[0058]

(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, what is necessary is just to be able to separate and control the information indicating the temperature gradient and the average information.

[0061] The first PID control means 6 _1, the average temperature and
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 for 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.

[0065] 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 conventional example of FIG. 41 and FIG. 42, and the portions corresponding to FIG. Reference numerals are assigned.

The average temperature / inclination temperature detecting means 5 comprises:
The feedback amounts PV1 and PV2 from the control target 3 corresponding to the detection outputs of the second temperature sensors 2 ₁ and 2 ₂ are added by the adder 8 as shown in FIG. while attenuation and outputs the average temperature Tav, feedback variable PV corresponding to detection outputs of the temperature sensors 2 _1, 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
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.

[0084] 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 characteristics of the control target 27 are shown in FIG. 42 described above, and from this characteristic, the transfer coefficients are 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, the total amount of heat distributed to each heater is assumed to be 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 (decoupling coefficient) is determined.

[0089] 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, from the mode conversion matrix Gm and the 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

[0093]

(Equation 3)

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

[0095]

(Equation 4)

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

[0097]

(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 expressed. You may make it calculate using a transfer function.

In the system shown in 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.

[0100] 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, the PV of the conventional example shown in FIGS.
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 simulation of this embodiment and the 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.

[0106] 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.

The conventional PI using the parameters shown 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.

[0109]

[Table 1]

[0110]

[Table 2]

When comparing FIG. 10 and FIG. 11, a temperature difference of 2 ° C. occurs in 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 uniformity 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. Here, CHR (Chien, Hrones and R
No overshooting of the target value response of Eswick) was used for average temperature control, and 20% of disturbance response overshoot 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 conventional example of FIG. 14, the settling time is as long as 29 seconds, and overshoot is 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 shown in 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 shown 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.

[0125] In the same manner as described _{la + lb · k 3 + lc} · k 4 = 0 ...... ld + le · k 5 + lf · k 6 = 0 ...... first gradient temperature Tt _1, the operation amount of the first gradient temperature Ht ₁ 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, 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.

[0129]

(Equation 6)

[0130]

(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 also 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

[0133]

(Equation 8)

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

[0135]

(Equation 9)

The pre-compensation matrix Gc is

[0137]

(Equation 10)

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

[0139]

[Equation 11]

In the above description, each PID control means controls the average temperature to the target average temperature or the gradient temperature to the target gradient temperature, respectively. The temperature is set by the user, but it is difficult for a user who has conventionally set the target temperature for each channel 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. Note that, in FIG. 21, the 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 shown in FIG. 18, the temperature deviation between the temperature detected by the temperature sensor of each channel and the target temperature SP, which is the feedback amount from the control object 27, is obtained, and the control is performed based on the temperature deviation for each channel. A mode converter 5 ″ for calculating the average temperature deviation and the inclination temperature deviation which are deviations 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, the above-mentioned mode converters 5, 5 '
Converts the detected temperatures from the plurality of temperature sensors into an average temperature and a gradient temperature, whereas the mode converter 5 ″ according to the present embodiment uses the detected temperatures from the plurality of temperature sensors. Is converted into a mean temperature deviation, which is a difference between the detected average temperature and the target average temperature, and is converted into a slope temperature deviation, which is a difference between the detected slope temperature and the target slope temperature. Is what you do.

That is, in the above example, the detected temperature is converted into the average temperature and the gradient temperature, and then the control deviation is obtained. In this example, the temperature deviation between the detected temperature and the target temperature is obtained, and the temperature deviation is obtained. The deviation is converted into an average temperature deviation and a gradient temperature deviation which are control deviations.

After the description of the function of the temperature controller of the present invention as described above, specific embodiments of the present invention will be described below.

FIG. 19 is a configuration diagram of a temperature control system including a temperature controller according to one embodiment of the present invention. The temperature controller of this embodiment has the same function as the temperature controller of FIG. And performs decoupling control based on the average temperature and the gradient temperature.

That is, the temperature controller according to the present embodiment comprises a mode converter 5 ″, first and second PID control means 6 ₁ and 6 ₂ and a pre-compensator (distribution means) in FIG.
7, is constituted by replacing the adder 80 _1, 80 ₂ and the first to fourth PID control means 6 ₁ '6 _4'.

The processing in the mode converter 5 ″, the first and second PID control means 6 ₁ and 6 ₂ and the pre-compensator (distribution means) 7 in FIG. using the transformation matrix Gm, first, a matrix G _{PI D} corresponding to the second PID control means 6 _1, 6 _2, and a Gc predistorter matrix corresponding to the predistorter 7, Gc × G _PID ×
Gm, which is added to the adder 8 shown in FIG.
0 _1, 80 ₂ and the first to fourth PID control means 6 ₁ '-
6 ₄ ′ and can be expressed as follows:

[0150]

(Equation 12)

The mode conversion matrix Gm and the pre-compensation matrix G
c can be obtained as described above, and FIG.
Since the PID parameters of the first and second PID control means 6 ₁ and 6 ₂ can also be obtained by auto-tuning, by solving the above determinant, the first to fourth PID control means 6 ₁ ′ to Each of the PID parameters 6 ₄ ′ can be obtained, whereby the mode converter 5 ″, the first and second PID control means 6 ₁ , 6 _2, and the pre-compensator (FIG. 18) are obtained. allocation means) 7, will be be implemented using adders 80 _1, 80 ₂ and the first to fourth PID control means 6 ₁ '6 _4' enables control based on the average temperature and the gradient temperature, The interference can be reduced.

Therefore, in the temperature controller of the present invention shown in FIG. 20, the operator can control the PIDs of the first to fourth PID control means 6 ₁ ′ to 6 ₄ ′ based on the above determinant.
A parameter may be calculated and set.

According to the present invention, although the number of PID control means is increased, the mode converter 5 ″ and the pre-compensator 7
Becomes unnecessary.

Note that in FIG. 20, the first and fourth
PID control means 6₁’, 6_Four′ Is the first and second temperature sensors.
Temperature deviation corresponding to the detected temperatures PV1 and PV2
Based on this, an operation signal is sent to the corresponding first and second heaters.
The same PI as before corresponding to each output channel
D control means, whereas the second PID control means 6
_Two'Corresponds to the detected temperature PV2 from the second temperature sensor
Operation signal to the first heater based on the temperature deviation
The third PID control means 6_Three’
Temperature deviation corresponding to the detected temperature PV1 from the first temperature sensor.
Outputs an operation signal to the second heater based on the difference
It is. That is, the second PID control means 6_Two’
4 PID control means 6_Four′ Controls the first PID
Control means 6 ₁’Control
The third PID control means 6_Three’
First PID control means 6₁′ Controls the fourth PI
D control means 6_Four’Control
The decoupling control means.
Works as

The present invention is not limited to a temperature controller having a plurality of input / output points as shown in FIG. 20, but may be constituted by combining a plurality of temperature controllers for single-point temperature control.

FIG. 21 shows a temperature controller 8 of such a single-point control.
1 _1-81 shows an example _{of 4} combined to four, its function is the same as the temperature regulator of FIG. 20. In addition, the first,
The second PID control means 6 ₁ ', 6 _2' of the operation amount adding adders 80 ₁ and the third, fourth PID control means 6 ₃ ',
6 ₄ adder 80 ₂ adds the operation amount of 'the first through fourth temperature controller 81 _{1-81 4,} for example, configured to be incorporated in the first, fourth temperature controller 81 _1, 81 ₄ Of course, it may be.

As described above, the temperature controllers 81 ₁ to 81 _{1 of the single-} point control are used.
By forming a combination of 81 _4, it can be realized inexpensively.

FIG. 22 is a configuration diagram of another embodiment of the present invention, and portions corresponding to FIG. 20 are denoted by the same reference numerals.

In the present embodiment, the operator operates the mode conversion matrix Gm, the pre-compensation matrix Gc, and the proportional gain kp, which is the PID parameter of the first and second PID control means 6 ₁ and 6 ₂ in FIG. Time constant Ti, differential time constant T
By setting _D , the calculating means 82 automatically calculates and sets the PID parameters of the _first to fourth PID control means 6 ₁ ′ to 6 ₄ ′. There is no need to set PID parameters.

In this embodiment, four PID control means 6 ₁ ′ to 6 ₄ ′ are provided for two-channel temperature control. However, at least one PID control means is provided. Even if three PID control means are used, a certain effect can be obtained.

For example, when the PID parameters of two PID control means 6 ₂ ′ and 6 ₃ ′ for decoupling are calculated, one gain is large and the other gain is almost 0.
, The other PID control means is omitted and FIG.
As shown in FIG. 3, three PID control means 6 ₂ ′,
6 ₃ ′ and 6 ₄ ′.

Although the above embodiment has been described with reference to the case of two channels, the present invention can be similarly configured for three or more channels. For example, in the case of three channels, as shown in FIG. And adders 80 ₁ to 8
0 ₃ and 9 of the first to ninth PID control means 6 ₁ '6
₉ 'can be composed.

In this case, each of the PID control means 6 ₁ ′ to 6 ₉ ′
Are the mode converter 5 ″ for the case of three channels and the first to third PIDs, as in FIG.
Mode conversion matrix Gm when configured by the control unit ₆₁ through ₃ and the predistorter 7, first to third PID control means 6 ₁
It is calculated using a matrix G _PID and precompensation matrix Gc corresponding to 6 _3.

In FIG. 24, the second PID control means 6 ₂ ′ controls the second channel corresponding to the second temperature sensor by controlling the first channel corresponding to the first temperature sensor. The third PID control means 6 ₃ ′ operates to eliminate the influence of the control of the third channel corresponding to the third temperature sensor on the first channel. And the fourth PID control means 6 ₄ ′ operates to eliminate or reduce the influence of the control of the first channel on the control of the second channel, 6th PI
The D control means 6 ₆ ′ operates to eliminate or reduce the influence of the control of the third channel on the control of the second channel, and further, the seventh PID control means 6 ₇ ′
The control of the first channel operates to eliminate or reduce the effect on the control of the third channel, and the eighth P
ID control unit 6 ₈ ', the control of the second channel, the third
In order to eliminate or reduce the influence on the control of the channel.

FIG. 25 is a block diagram of a main part of another embodiment of the present invention. For example, in a heat treatment apparatus, if a detection signal line from a temperature sensor is disconnected while performing a heat treatment on a wafer, it can be detected immediately and control can be performed with the effect reduced as much as possible. Thus, it is desired to suppress the occurrence of defective products.

Therefore, in this embodiment, there is provided a mode converter with sensor disconnection compensation 5a for detecting disconnection of the temperature sensor and compensating for the disconnection. The mode converter with sensor disconnection compensation 5a has the above-mentioned mode converter. In addition to the converter 5, a disconnection detecting means 83 for detecting disconnection of the detection signal lines from the three temperature sensors, and a detection output of the temperature sensor in which the disconnection is detected is replaced with an average temperature detected by the temperature sensors. Replacement means 84.

The configuration for detecting and compensating for the disconnection of the detection signal line from the temperature sensor is provided in the mode converter 5 as the mode converter 5a with sensor disconnection compensation as in this embodiment. However, it is needless to say that a separate device may be provided outside the mode converter 5.

The disconnection detecting means 83 compares the average temperature from the mode converter 5 with the detected temperatures PV1 to PV3 from the first to third temperature sensors, respectively, and if the difference exceeds a predetermined threshold value. when the is provided with a first to third comparators 85 ₁ to 85 ₃ which outputs an average temperature of a disconnection, substitution means 84, the temperature sensor in response to the output of the comparators 85 ₁ to 85 ₃ First to third switches 86 ₁ that switch the output to the average temperature from comparators 85 _{1 to} 85 ₃ and output the average temperature.
It has a to 86 _3.

In FIG. 25, the detection signal line from the second temperature sensor is broken, the signal is detected by the _second comparator 852, and the average temperature is output to the _second switch 862. the second switch 86 _2, the average temperature calculated in the mode converter 5 instead of the output PV2 of the second temperature sensor, and outputs the mode converter 5 as the replacement temperature PVx.

The mode converter 5 includes first to third comparators 8
5 _{1-85 3} in response to an output, without using the substituted average temperature corresponding to the temperature sensor disconnection is detected,
The average temperature may be calculated only from the detected temperature from the temperature sensor that is not disconnected, or may be calculated using the replaced average temperature. Note that the gradient temperature is calculated using the replaced average temperature.

FIG. 26 shows another embodiment of the present invention.
5 is a diagram corresponding to FIG. 5, and corresponding portions are denoted by the same reference numerals.

In the above-described embodiment, the output of the temperature sensor in which the disconnection is detected is replaced with the average temperature given through comparators 85 _{1 to} 85 _{3. In} this embodiment, the replacement is performed. The means 84 includes a plurality of proximity point average calculation circuits 87 ₁ to 87 n for calculating the average of the detected temperatures from the plurality of temperature sensors disposed in the vicinity of each temperature sensor. When a disconnection is detected, The average temperature of the detected temperatures of the plurality of proximity points calculated by the proximity point average calculation circuits 87 _{1 to} 87 n corresponding to the disconnected temperature sensors is replaced and output.

As the plurality of temperature sensors arranged in the proximity position, for example, there are two temperature sensors arranged on both sides (on both sides) of a certain temperature sensor.

FIG. 27 is a block diagram of a control system according to still another embodiment of the present invention.
Alternatively, it corresponds to the mode converter 5a with sensor disconnection compensation of FIG.

[0175] In this embodiment, when replacing the detection output by detecting the disconnection of the temperature sensor as described above is to modify the PID parameters of the PID control means ₆₁ through _3.

That is, when the detection output of the disconnected temperature sensor is replaced with the detection temperature of another adjacent temperature sensor, the distance of heat conduction becomes longer than that of the original disconnected temperature sensor, so that there is no waste. In this embodiment, a PID parameter corrector 88 is provided, and the PID parameter corrector 88 detects a disconnection and replaces the detection output of the temperature sensor. when the weaker the proportional gain to modify the PID parameters of the PID control means ₆₁ through _3, or is to increase the integration time and derivative time. Note that all of the proportional gain, the integration time, and the differentiation time may be corrected, or any one of them may be corrected.

FIG. 28 is a diagram showing another embodiment of the present invention.
7 is a diagram corresponding to FIG. 7, and corresponding portions are denoted by the same reference numerals.

[0178] In the above-described embodiment, when the disconnection is to replace the detection output of the detecting temperature sensor, whereas modified the PID parameters of the PID control means ₆₁ through _3, in this embodiment in the mode, the PID control means 6 ₁ are replaced with an operation signal switch 89 for switching the operation signal from the 6 _3, an operation signal to the heater corresponding to the temperature sensor disconnection is detected by the operation signal switch 89 , For switching to an operation signal for a heater close to the heater.

FIG. 29 is a configuration diagram of a mode converter 5a with sensor disconnection compensation according to still another embodiment of the present invention.
In this embodiment, the mode converter 5 calculates the detected temperatures PV1 to PV3 of the first to third temperature sensors as an average temperature,
The first gradient temperature based on the detected temperature PV1 of the first temperature sensor and the detected temperature PV2 of the second temperature sensor, the detected temperature PV2 of the second temperature sensor, and the detected temperature PV3 of the third temperature sensor. And a second gradient temperature.

In this embodiment, when one of the temperature sensors is disconnected, the disconnection is detected by utilizing the fact that the inclination temperature greatly changes.

The disconnection detecting means 83 of this embodiment compares the first and second gradient temperatures with a threshold value.
Second comparator 90 _1, 90 ₂ and, the comparators 90 _1, 90 ₂ first to third output of the given gate circuits 91 ₁ to 91 ₃
When the first temperature sensor is disconnected, the first
The output of the comparator 90 ₁ first exceeds the threshold gradient temperature greatly changes in becomes the high level first gate circuit 9
1 ₁ gives the detection output, the second temperature sensor is broken, first, first it exceeds the threshold value the second gradient temperature greatly changes, the output of the second comparator 90 _1, 90 ₂ in giving a high level of becoming a second gate circuit 91 ₂ is detected outputs together, and when the third temperature sensor is broken, the second comparator exceeds the threshold value the second gradient temperature changes greatly 90 ₂
The third gate circuit 91 ₃ outputs a high level is to provide a detectable output.

Replace the detection output of the disconnected temperature sensor
The replacement means 84 is provided for each gate circuit 91. ₁~ 91_ThreeDetection output
-To-third switching devices 92 each provided with₁~
92_ThreeAnd a temperature close to the disconnected temperature sensor.
The detection output of the degree sensor is set as the replacement output PVx.
The first switch 92₁Is the third temperature
The detection temperature PV3 of the sensor is changed to the second and third switchers 9
2_Two, 92_ThreeIs the detection temperature PV1 of the first temperature sensor,
Configured to replace the detection output of the disconnected temperature sensor
Have been.

The disconnection detection of the present invention is not limited to the control based on the average temperature and the gradient temperature as described above, but can be similarly applied to a conventional example in which control is performed for each channel.

FIG. 30 is a block diagram of a control system in which the disconnection detection of the present invention is applied to a conventional example, and FIG. 31 is a block diagram of the sensor disconnection compensator 93. Incidentally, in FIG. 30, 94 ₁ to 94 ₃ is a PID controller for each channel.

The sensor disconnection compensator 93 is provided with first to third switches 95 _{1 to} 95 ₃ provided through _first to third switches 95 _{1 to} 95 3.
Is provided with an average temperature calculator 96 for calculating the average temperature of the detected temperatures PV1 to PV3 from the temperature sensors, and the average temperature from the average temperature calculator 96 and the detected temperature P of each temperature sensor.
V1 to PV3 are compared by first to third comparators 97 _{1 to} 97 ₃ , and when the difference exceeds a predetermined threshold value, it is determined that a disconnection has occurred, and the corresponding switching units 95 _{1 to} 95 ₃ and outputs an average temperature, switch 95 _{1-95 3,} the average temperature is to output is replaced as the detection output of the temperature sensor disconnected. Note that the average temperature calculator 96 may calculate the average temperature using the average temperature that has been detected and replaced by the disconnection, or may calculate the average temperature without using the average temperature that has been detected and replaced by the disconnection. It may be calculated.

In this example, although the disconnection is detected by comparing with the average temperature, the disconnection may be detected by calculating the inclination temperature and comparing with the inclination temperature.

The disconnection compensation structure shown in FIGS. 30 and 31 can be easily applied to the temperature controller of the present invention shown in FIG. 24 described above.

In each of the above embodiments, the temperature of the control object such as the heat treatment board is detected by using a plurality of temperature sensors. As another embodiment of the present invention, as shown in FIG. Instead of a plurality of temperature sensors, an infrared camera (thermo camera) 98 may be used to detect the temperature of the control target in a non-contact manner.

In the case of a planar control object, the infrared camera 9
8 is input to the mode converter 5, and the information of the average and the gradient of the temperature distribution is extracted from a large amount of information and controlled. Assuming that the number of heaters that can be controlled by n is the number of pixels of the thermal image for detecting the temperature is m, the mode converter 5 has a matrix of n inputs and m outputs. In the case of FIG. 32, the number m of heaters
Is 2. The average temperature PV is calculated as the average of all the pixels to be controlled, and the slope temperature PV may be a portion where the temperature changes most rapidly between the two heaters.

Further, the average value of the pixels of the thermal image corresponding to the area where the temperature was detected by each of the plurality of temperature sensors (or the area where each heater is installed) is calculated as the detected temperature detected by each temperature sensor. Then, the configuration of each of the above-described embodiments can be applied as it is. Most simply, for example, if the temperature of the pixel of the thermal image corresponding to the center position of the installation location of each temperature sensor (or the center position of each heater) is the detected temperature of each temperature sensor, The form can be applied as it is. That is, FIG. 32 shows the case where the detection output of the infrared camera 98 is the temperature of two pixels corresponding to the two temperature sensors.

When the infrared camera 98 is used, for example, as shown in FIG. 33, the temperature of the object to be heated 100 such as a wafer to be heated by the heat treatment board 99 can be controlled while directly observing it. The temperature of the object to be heated 100 can be controlled with higher accuracy than when the temperature of the object to be heated 100 is detected and controlled by a contact-type temperature sensor such as a thermocouple. Moreover, the detection point for detecting the temperature can be easily changed.

FIGS. 34 and 35 are block diagrams of another embodiment of the present invention. Parts corresponding to FIGS. 32 and 33 are denoted by the same reference numerals.

In this embodiment, the control of the tilt temperature is
While the average temperature is controlled by a signal from the infrared camera 98, a contact-type temperature sensor 2 such as a thermocouple is used. By using the detection signal of the contact-type temperature sensor 2 that can accurately measure the absolute value of the temperature as the average temperature, the accuracy of the average temperature control can be increased, and the poor absolute value accuracy of the infrared camera 98 can be compensated.

FIG. 36 is a block diagram of still another embodiment of the present invention, and portions corresponding to FIG. 32 are denoted by the same reference numerals.

In this embodiment, multipoint non-contact heating 101 is performed by laser scanning or the like instead of the heater, and the temperature is finely and uniformly controlled.

By associating the area heated by each of the plurality of heaters with the point heated by the two-dimensional laser scanning,
Each of the above embodiments can be applied as it is.

In FIG. 36, valid pixels are selected from the temperature detection signals for the number of pixels detected by the infrared camera 98, and the average temperature and the gradient temperature signals among them are calculated by the mode converter 5. , The average temperature and the gradient temperature are controlled.

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 may be applied to other control systems such as on / off control, proportional control, integral control, and proportional integral control. Applicable.

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. 37, for temperature control of a heat treatment board in a single-wafer CVD apparatus. You can do it. In FIG. 37, the heat treatment plate 61 on which the wafer 60 is placed is divided concentrically into an outer circle portion 62, an intermediate portion 63, and a center 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.

Although the above embodiment has been described with reference to application to temperature control using a heating means such as a heater, it goes without saying that application to temperature control using a Peltier element, a cooler, or the like is also possible. 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.

[0204]

As described above, according to the present invention, it is possible to reduce the interference in the control of the control target having the interference.

Further, according to the present invention, the disconnection of the detection signal line of the temperature detecting means is detected and replaced with the average temperature or the detected temperature of another temperature detecting means disposed close to the detecting signal line. The temperature of the control target can be controlled to a state close to a desired state. For example, it is possible to suppress the occurrence of defective products in the heat treatment of the heat treatment apparatus.

[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 block diagram of still another embodiment of the present invention.

FIG. 19 is a configuration diagram of a control system according to one embodiment of the present invention.

FIG. 20 is a configuration diagram of the temperature controller of the present invention corresponding to FIG. 19;

FIG. 21 is a configuration diagram of a temperature controller according to another embodiment of the present invention.

FIG. 22 is a configuration diagram of a control system according to still another embodiment of the present invention.

FIG. 23 is a configuration diagram of a temperature controller according to another embodiment of the present invention.

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

FIG. 25 is a block diagram of a main part of another embodiment of the present invention.

FIG. 26 is a block diagram of a main part of another embodiment of the present invention.

FIG. 27 is a configuration diagram of a control system according to another embodiment of the present invention.

FIG. 28 is a configuration diagram of a control system according to still another embodiment of the present invention.

FIG. 29 is a block diagram of a main part of another embodiment of the present invention.

FIG. 30 is a configuration diagram of a control system according to another embodiment of the present invention.

FIG. 31 is a block diagram of a main part of FIG. 30;

FIG. 32 is a configuration diagram of a control system according to another embodiment of the present invention.

FIG. 33 is a configuration diagram of the temperature detection of FIG. 32.

FIG. 34 is a configuration diagram of a control system according to still another embodiment of the present invention.

FIG. 35 is a configuration diagram of the temperature detection of FIG. 34.

FIG. 36 is a configuration diagram of a control system according to another embodiment of the present invention.

FIG. 37 is a view showing another heat treatment apparatus.

FIG. 38 is a diagram showing a configuration of a thermal oxidation device.

FIG. 39 is a configuration diagram of a system that controls two control targets without interference.

40 is a waveform chart at the time of auto-tuning of the system of FIG. 39.

FIG. 41 is a configuration diagram of a system that controls a control target having interference.

FIG. 42 is a diagram showing a configuration of a control target in FIG. 41.

FIG. 43 is a waveform chart at the time of auto-tuning of the system of FIG. 41.

[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, 6 1 '~6} 9' PID controller 7 allocation means 15 the heater plate 18 thermally oxidized Device 83 Disconnection detecting means 84 Replacement means 98 Infrared camera

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Seiya Narimatsu 10th Hanazono Todocho, Ukyo-ku, Kyoto-shi, Kyoto Prefecture Inside (72) Inventor Masahito Tanaka 10th Hanazono-Todocho, Ukyo-ku, Kyoto-shi, Kyoto O-Muron Inside (72) Inventor Hiroki Kataoka Omron, Inc. (10) Hanazono Todocho, Ukyo-ku, Kyoto-shi, Kyoto (72) Inventor Tsunetoshi Omron (10) Hanazono-Todocho, Ukyo-ku, Kyoto, Kyoto ( 72) Inventor Hideki Kobori F-term (reference) 5H004 GA01 GB15 HA01 HB01 JB08 KA03 KA71 KB02 KB04 KB06 5H209 AA11 BB02 CC01 DD02 EE05 FF08 GG04 SS07 TT08 5H323 A05 AA27 BB04 CA01 CB02 CB18 CB42 DB06 FF01 GG02 GG16 HH03 KK05 LL01 LL02 MM02 QQ02 RR01 SS01 TT01

Claims (9)

[Claims] 1. A plurality of operation means individually corresponding to the detection means based on respective deviations of a plurality of pieces of detection information from a plurality of detection means for respectively detecting a physical state of a control target and a plurality of target information. A control device comprising a plurality of state control means for respectively outputting operation signals to the control means, wherein based on a deviation corresponding to a certain detection means, another operation means different from the operation means corresponding to the certain detection means A control device comprising at least one decoupling control means for outputting an operation signal to the control device. 2. The method according to claim 1, wherein the plurality of state control units and the non-interference control unit convert each deviation between the plurality of pieces of detection information and the plurality of target information into a deviation of information indicating a gradient of the physical state of a control target. A conversion unit for converting the information indicating the representative state of the physical state into a deviation of the information indicating the gradient or the deviation of the information indicating the representative state from the conversion unit. A plurality of state control means, and an operation signal from each of the state control means, a plurality of operation means, control by each state control means,
2. The control device according to claim 1, wherein the control device has a function as a distribution unit that distributes such that the influence on the control by the other state control unit is eliminated or reduced. 3. The method according to claim 1, wherein each of the plurality of detected temperatures from a plurality of temperature detecting means for detecting a temperature of the control target and a plurality of target temperatures respectively correspond to the temperature detecting means. What is claimed is: 1. A temperature controller comprising a plurality of temperature control means for outputting operation signals to a plurality of heating (or cooling) means for heating (or cooling) a controlled object, wherein a temperature deviation corresponding to a certain temperature detection means is provided. And at least one decoupling control means for outputting an operation signal for a heating (or cooling) means different from the heating (or cooling) means corresponding to the certain temperature detecting means. And temperature controller. 4. The temperature control means and the decoupling control means convert each temperature deviation between the plurality of detected temperatures and the plurality of target temperatures into a gradient temperature deviation, and convert the temperature deviation into a representative temperature deviation. Conversion means for converting; a plurality of temperature control means for outputting operation signals based on the deviation of the inclination temperature or the deviation of the representative temperature from the conversion means; and the operation signal from each of the temperature control means, Multiple heating (or cooling) means for heating (or cooling) the object,
4. The temperature controller according to claim 3, wherein the temperature controller has a function as a distribution unit that distributes the control by each temperature control unit so as to eliminate or reduce the influence on the control by the other temperature control units. 5. The temperature controller according to claim 4, wherein the representative temperature is an average temperature based on a plurality of detected temperatures. 6. A disconnection detecting unit for detecting disconnection of a detection signal line of the plurality of temperature detecting units, wherein the disconnection detecting unit compares each detected temperature with the average temperature or compares the detected temperature with a threshold temperature and a threshold value. The temperature controller according to claim 4, wherein the disconnection is detected based on the comparison. 7. The temperature according to claim 6, further comprising a replacement unit for replacing a detection output of the temperature detection unit in which the disconnection is detected with an average temperature of a plurality of detection temperatures or a detection temperature of another temperature detection unit disposed in proximity. Regulator. 8. The temperature controller according to claim 3, wherein said temperature detecting means is an infrared camera. 9. The temperature controller according to claim 3, a heat treatment furnace or a heat treatment board as a control object, and a plurality of heating (or cooling) for heating (or cooling) the heat treatment furnace or the heat treatment board. A heat treatment apparatus comprising: a plurality of temperature detecting means for detecting a temperature of the heat treatment furnace or the heat treatment plate;