JP2002168523A - Fluid temperature control device and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluid temperature control device capable of meeting the solid difference of a flow control valve, effectively suppressing an overshoot and completely meeting the disturbance of a load. SOLUTION: Working fluid is cooled by cooling water in a heat exchanger 106, and then, heated by a lamp heater 108 to obtain desired temperature. For the control of the flow control valves 112 and 114 of cooling water, two kinds of tables, are used, including a table for compensating the nonlinear cooling characteristics of the heat exchanger 106 and a table for compensating the nonlinear flow characteristics of the proportional valves 112 and 114. The table for compensating the characteristics of the proportional valves defines a rate of change of flow relative to each position of the number of pulses which is generated upon movement of the number of one pulse from the position. The table for compensating the characteristics of the proportional valves is adapted to the characteristics of each proportional valve by applying a parameter showing the sold difference of the proportional valves. During transient time, the proportional valves are controlled in accordance with the changing speed of current temperature. Upon setting, the proportional valves are controlled so that the output of the lamp heater 108 is located within a proper output range.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for controlling the temperature of a fluid flowing through a pipe.

[0002]

2. Description of the Related Art One of applications in which a fluid temperature control device is used is temperature control of a vacuum chamber used in a semiconductor manufacturing apparatus. For example, in the case of a vacuum chamber 20 of an etching apparatus as shown in FIG.
Is in a high temperature range of 80 ° C. or higher, the lid 22 is in a low temperature of about −15 ° C., and the electrode 24 on the wafer 23 is in a range of −20 ° C. to 8 ° C.
It is necessary to control the temperature to a low temperature range of about 0 ° C. Outer wall 21,
The temperature control of the lid 22 and the electrode 24 is performed by circulating pipes in respective places and flowing a temperature-controlled working fluid through the respective pipes. Here, the working fluid is water, ethylene glycol or florinate (FLUO
RINERT) (registered trademark).

For example, for controlling the temperature of the electrode 24 in a low temperature range, a fluid temperature control device (hereinafter, referred to as a “low temperature device”) 30 as shown in FIG. 2 can be used. Further, for example, for temperature control in a high temperature region for the outer wall 21,
For example, a fluid temperature control device (hereinafter, referred to as “high-temperature device”) 50 as shown in FIG. 3 can be used.

[0004] The low-temperature machine 30 shown in FIG. 2 has a fluid circulating supply system 31 in which a working fluid is supplied to a chiller (cooler).
32 or bypass passage 35, halogen lamp heater 3
3. Circulating through the vacuum chamber 20 in order. The working fluid is cooled as it passes through a chiller (cooler) 32, is then heated as it passes through a heater 33, and is supplied to the vacuum chamber 20. Opening control of the two flow control valves 34 and 36 provided in the chiller passage 37 and the bypass passage 35 and output control of the halogen lamp heater 33 so that the temperature of the working fluid becomes the target temperature at the inlet of the vacuum chamber 20. Is performed.

The high-temperature unit 50 shown in FIG. 3 has a fluid circulation supply system 51 in which a working fluid is supplied by a heater / cooler 52 having a halogen lamp heater and a cooling water channel therein, and a vacuum chamber 20 (for example, an outer wall thereof). 21). As the working fluid passes through the heater cooler 52, it is cooled by the cooling water and heated by the halogen lamp heater, and
Supplied to The opening control of the flow rate control valve 62 of the cooling water and the output control of the halogen lamp are performed so that the temperature of the working fluid becomes the target temperature at the inlet of the vacuum chamber 20.

In both the low temperature machine 30 and the high temperature machine 50, two types of heat exchangers are used to adjust the temperature of the working fluid. That is, a heat exchanger for cooling the working fluid with the cooling water and a heat exchanger for heating the working fluid with the heater. A conventional apparatus for controlling the temperature of a fluid using such two types of heat exchangers is disclosed in JP-A-2000-28.
No. 4832.

[0007] The conventional temperature control device described in Japanese Patent Application Laid-Open No. 2000-284832 performs control having the following characteristics.

The first feature relates to control of a flow control valve (for example, a proportional valve) for adjusting the flow rate of the working fluid or the cooling water. Generally, the opening / closing operation of the proportional valve is performed by a motor, and the opening / closing amount of the flow control valve is controlled by the operation amount (number of pulses) applied to the motor driver. However, the relationship between the number of added pulses and the rate of change of the flow rate (the flow rate characteristic of the flow rate control valve) is non-linear. In other words, the flow rate change rate when the same number of pulses is applied is not constant, but differs depending on the opening position of the flow control valve. Therefore, in the conventional device, by introducing an opening-pulse number table having a characteristic that compensates for the non-linear flow characteristic of the flow control valve, a certain ideal characteristic (the flow rate can be reduced to a linear characteristic). An opening-flow rate characteristic having a gamma characteristic such that the smaller the value is, the higher the control resolution becomes.) This eliminates the need to take into account the non-linear characteristics of the flow control valve in calculating the opening of the flow control valve, thereby simplifying the control process and improving control accuracy.

The second feature relates to control during transition (when the current temperature is away from the target temperature).
When the deviation between the target temperature of the working fluid and the current temperature increases, for example, when the target temperature of the working fluid is changed, the control operation of the conventional device enters a rapid heating mode or a rapid cooling mode. In the rapid heating mode, the cooling water flow control valve or the working fluid flow control valve flowing through the chiller is closed to the minimum opening. In the rapid cooling mode, the flow rate control valve for the cooling water or the flow rate control valve for the working fluid flowing through the chiller is opened to the maximum opening.
Responsiveness is improved by such a rapid heating or rapid cooling operation in which the opening degree of the flow control valve is set to a minimum or a maximum.

The third feature relates to control at the time of settling (when the current temperature is near the target temperature). When the current temperature falls in the range near the target temperature, the control operation of the conventional device enters a settling mode. In the settling mode, the output value of the halogen lamp heater is controlled to a predetermined appropriate value by controlling the opening of the flow control valve for the cooling water or the flow control valve for the working fluid flowing through the chiller to a predetermined value corresponding to the target temperature. Keep within range. In this state, when disturbance (temperature fluctuation due to heat generated in a process performed in the vacuum chamber) is applied to the temperature of the working fluid, the disturbance is responded to by adjusting the output power of the halogen lamp heater. Since the output power of the halogen lamp heater can be adjusted at high speed and with high precision, it is possible to immediately and accurately respond to disturbances, and it is easy to maintain the temperature of the working fluid at the target temperature.

[0011]

The above-mentioned conventional apparatus has the following problems.

First, there is an individual difference in the flow characteristics of the flow control valve. That is, even with the flow control valves of the same model, the flow characteristics of each product slightly differ. Therefore, the above-described opening degree-pulse number table has to have a wide margin covering the distribution of the flow rate characteristics due to the individual difference. As a result, the opening-pulse number table is not always optimal for a particular flow control valve product.

Second, the ability to suppress overshoot (including undershoot) is not yet sufficient, and the process can be started in the vacuum chamber after the current temperature of the working fluid reaches the target temperature. Is that it is not yet short enough. One of the causes is that the cooling characteristic of the heat exchanger for heat exchange between the working fluid and the cooling water is non-linear. That is, even if the flow rate of the cooling water is the same, the cooling capacity differs depending on the temperatures of the working fluid and the cooling water. The greater the temperature difference between the working fluid and the cooling water, the greater the cooling capacity. Therefore, the amount of cooling water for obtaining the same cooling capacity must be changed according to the temperature of the working fluid. Also, the cooling capacity for the same amount of cooling water differs depending on the temperature of the cooling water.
Further, as another cause, various heat sources such as a motor included in the device also affect the temperature of the working fluid. But,
The control method of the rapid heating or rapid cooling mode of the conventional apparatus cannot sufficiently cope with such problems as the nonlinear characteristics of the heat exchanger and the influence of other heat sources, and it is difficult to sufficiently suppress the overshoot. .

Third, the ability to respond to disturbance is not sufficiently large. That is, in the conventional apparatus, the disturbance is controlled by controlling the output of the halogen lamp heater. Therefore, it is difficult to completely cope with the disturbance unless the margin of the output capability of the halogen lamp heater is made very large.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a fluid temperature control device capable of coping with the individual difference of the flow control valve.

Another object of the present invention is to provide a fluid temperature control device capable of favorably suppressing overshoot.

Another object of the present invention is to provide a fluid temperature control device having a short settling time.

Another object of the present invention is to provide a fluid temperature control device which can sufficiently cope with disturbances.

[0019]

A fluid temperature control device according to a first aspect of the present invention includes a heat exchanger for flowing heat between a first fluid and a second fluid for performing heat exchange between the two fluids. A flow control valve for controlling a flow rate of at least one of the first and second fluids flowing through the heat exchanger; and a control amount of a position of the flow control valve for controlling a heat exchange capacity of the heat exchanger. A valve control unit that applies the operation amount at that position to the flow control valve. Then, the valve control unit (1) calculating means for calculating the manipulated variable of the heat exchange capacity in order to control the heat exchange capacity in the heat exchanger, and (2) nonlinearity of the cooling characteristic of the heat exchanger Heat exchanger compensating means that defines the relationship between the manipulated variable of the heat exchange capacity and the manipulated variable of the flow rate flowing through the flow control valve, and (3) the non-linearity of the flow characteristic of the flow control valve. A flow control valve compensating means that defines a relationship between the operation amount of the flow rate and the operation amount of the position of the flow control valve so as to compensate, (4)
Means for determining an operation amount of a position to be applied to the flow control valve from the operation amount of the heat exchange capacity calculated by the arithmetic means, using the heat exchanger compensation means and the flow control valve compensation means.

According to this fluid temperature control device, it is possible to cope well with both the nonlinear characteristics of the heat exchanger and the nonlinear characteristics of the proportional valve. As a result, the overshoot is more effectively suppressed and the settling time is reduced. Can be shortened.

In a preferred embodiment, the heat exchanger compensating means and the flow control valve compensating means are each a look-up table.

In a preferred embodiment, the flow control valve compensating means sets a relative flow rate change amount that is generated when one unit of the position operation amount is applied to each position that the flow control valve can take at each position. You have defined a value.

In a preferred embodiment, the flow control valve compensating means defines a relationship between the flow control amount and the position control amount based on a common flow characteristic that does not depend on individual differences of the flow control valves, The personality of the equipped flow control valve is fetched as a parameter, and the definition is adjusted to match the personality of the equipped flow control valve using the fetched parameter. This allows
It can cope with individual differences of the flow control valve.

In a preferred embodiment, there is provided an auto-newning function for automatically detecting the personality of the equipped flow control valve and providing the detected personality as the parameter to the flow control valve compensating means. .

A fluid temperature control device according to a second aspect of the present invention is a heat exchanger for cooling a working fluid with a cooling fluid, in which the working fluid and the cooling fluid flow, and a working fluid or a cooling fluid flowing in the heat exchanger. A flow control valve that controls the flow rate of the fluid, an electric heater that heats the working fluid that exits the heat exchanger, and an output power of the heater that controls the temperature of the working fluid that exits the heater to a target temperature And a valve controller that operates a flow control valve to control the cooling capacity of the heat exchanger. The valve control unit includes: (1) a transient valve control unit that operates the flow control valve in accordance with the rate of change of the current temperature during a transition before the current temperature of the working fluid reaches the target temperature; (2) And a setting valve control means for operating the flow control valve so that the output power of the heater falls within a predetermined appropriate output range at the time of settling after the current temperature has reached the target temperature.

According to the fluid temperature control device, the valve control is performed in accordance with the current temperature change speed during the transition, so that the overshoot can be more effectively suppressed and the settling time can be shortened.

In a preferred embodiment, the settling time valve control means includes means for feeding back the reference output power from the heater control unit, and when the reference output power is out of the proper output range, the reference output power and the proper output range. Means for operating the flow control valve in accordance with the magnitude of the deviation of This improves the ability to respond to load disturbances.

In a preferred embodiment, the settling time valve control means uses a relatively large control gain to control the operation amount of the flow control valve during the overshoot immediately after the current temperature reaches the target temperature. It has means for calculating and means for calculating the operation amount of the flow control valve using the control gain of a relatively small value after the overshoot is over. Thus, overshoot can be more effectively suppressed, and control can be stabilized after overshoot is over.

In a preferred embodiment, the settling valve control means includes means for detecting occurrence of hunting in which the output power of the heater vibrates in a width exceeding an appropriate output range, and controlling flow rate control when hunting is detected. Means for reducing the control gain used to calculate the operation amount of the valve. Thereby, hunting can be effectively suppressed.

In a preferred embodiment, the heater control means controls the output power of the heater by a speed-type I-PD control method using a relatively large control gain at the time of overshoot during transition and during settling. It has a means for calculating the amount and a means for calculating the manipulated variable of the output power of the heater by a PID control method using a relatively small control gain after overshooting at the time of settling.

According to a third aspect of the present invention, there is provided a control device for a flow control valve, comprising: means for determining an operation amount of a flow rate; and an operation amount of the flow control valve so as to compensate for non-linearity of a flow characteristic of the flow control valve. Flow control valve compensating means that defines the relationship between the operation amount of the position of the flow control valve and means for determining the operation amount of the position corresponding to the determined operation amount of the flow rate using the flow control valve compensating means. Prepare. Then, the flow control valve compensating means defines the relationship between the flow operation amount and the position operation amount based on a common flow characteristic that does not depend on the individual difference of the flow control valve, and the flow control valve to be controlled is The personality possessed is captured as a parameter, and the definition is adjusted using the captured parameter so as to match the personality of the equipped flow control valve.

According to this valve control device, it is possible to satisfactorily cope with individual differences of the flow control valve.

[0033]

FIG. 4 shows a mechanical system configuration of a fluid temperature control device according to an embodiment of the present invention.

In the fluid temperature control device 100, a path 101 indicated by a thick solid line is a path through which the working fluid circulates. There, the pump 10
The working fluid sent out by 3 is first divided into the main path 104 and the bypass path 105, passes through the heat exchanger 106 for cooling in the main path 104, and then merges, and then a lamp using a halogen lamp is used. It passes through a heater (heat exchanger for heating) 108 and is supplied to a load such as a vacuum chamber (not shown), and then returns to the tank 102 again. The bypass 105 has a flow rate sensor 107 for measuring the flow rate of the working fluid flowing therethrough. A temperature sensor 10 for measuring the current temperature of the working fluid (current temperature of the working fluid supplied to the load) at the outlet of the lamp heater 108 (the outlet of the fluid temperature control device 100).
There are nine. The working fluid always flows at a constant flow rate in the passage 100, is cooled when passing through the heat exchanger 106, and is heated when passing through the lamp heater 108, whereby the temperature is controlled.

The path 111 shown by a thin solid line is
This is a flow path of cooling water for cooling the working fluid. There, the cooling water sent out by the pump 103 first splits into the main path 113 and the bypass path 115, passes through the heat exchanger 106 in the main path 113, merges, and is controlled by the constant flow valve 117. It is flowing at a constant flow rate. The main path 113 and the bypass path 115 are respectively provided with proportional valves 112 and 113 for controlling the flow rate of the cooling water.

FIG. 5 shows a hardware configuration for performing the control operation of the fluid temperature control device 100.

As shown in the figure, the CPU board (controller) 121 takes in the detected value of the temperature of the working fluid supplied to the load from the temperature sensor 109, and
7, the detected value of the flow rate of the working fluid that bypasses the heat exchanger 106 is taken in.
The detected value of the current flowing through the lamp is captured. Then, the controller 121 performs a later-described arithmetic processing based on the detected value in order to match the temperature of the working fluid at the outlet with the predetermined target temperature, and controls the flow rate of the cooling water according to the result. The proportional valves 112 and 114 for controlling the opening amount are controlled, and the output power of the lamp heater 108 is controlled. The controller 121 also starts and stops the pump 103. The controller 121 is connected to the operation panel 122 and the host computer 123, and is connected to the operation panel 122 or the host computer 123.
In accordance with the command sent from the controller, the control operation described above is started and ended, the target temperature is set, and the like.

FIG. 6 shows a basic functional configuration of the controller 121.

The function of the controller 12 is roughly divided into a valve controller 131 and a lamp controller 132. The valve controller 131 controls the proportional valve 11 for controlling the amount of cooling water.
2 and 114 are controlled. The lamp controller 132 controls the output power of the lamp heater 108. The two kinds of control of the valve controller 131 and the lamp controller 132 are combined to control the current temperature (PV) at the outlet of the working fluid to the target temperature (SV). The control role of the controller 132 differs as follows.

That is, the role of directly controlling the current temperature (PV) of the working fluid to the target temperature (SV) is as follows.
The lamp heater 108 is under the control of the lamp controller 132. Therefore, the lamp controller 132
Inputs the current temperature (PV) and the target temperature (SV), performs PID calculation on the difference between the two, and controls the output power of the lamp heater 108 so that the difference becomes zero. Since the output power of the lamp heater 108 can be controlled at high speed and with high accuracy, controlling the temperature of the working fluid thereby enables highly responsive and highly accurate temperature control.

On the other hand, the control of the cooling amount by the cooling water in the heat exchanger 106 has low response and low control accuracy. Therefore, the role of the cooling amount control performed by the valve controller 131 is as follows.
The purpose is to control the output power of the lamp heater 108 to fall within a predetermined appropriate output range for fulfilling the above-mentioned role. Therefore, the valve controller 131 inputs the target temperature (SV) of the working fluid, the current temperature (PV), and the output power of the lamp controller 132 (in particular, for example, an integral component that is hardly affected by disturbance such as a temperature detection error). Then, arithmetic processing is performed using the input amounts by a method described later, and the proportional valves 112 and 114 are operated based on the result.

In the basic configuration described above, in particular,
The principle is applied to the present invention in a specific control method of the proportional valves 112 and 114 performed by the valve controller 131. Therefore, a method of controlling the proportional valves 112 and 114 performed by the valve controller 131 will be described in detail below.

The main items newly adopted in the control of the proportional valves 112 and 114 are as follows.

(1) Two types of tables are used: a table for compensating for the non-linear cooling characteristics of the heat exchanger 106 and a table for compensating for the non-linear flow characteristics of the proportional valves 112 and 114.

(2) The table for compensating the flow characteristics of the proportional valves 112 and 114 is not an absolute value of the absolute flow rate for each pulse number position, but a unit amount (pulse number) for each pulse number position from that position. For example, it is defined as a relative value of a change rate of the flow rate (for example, a ratio of a flow rate change amount to a total flow rate of the cooling water) generated when the flow rate is changed by one pulse.

(3) The table for compensating the flow characteristics of the proportional valves 112 and 114 is adapted to each proportional valve by applying a parameter representing the individuality (individual difference) of each proportional valve to this table. It is becoming something.

(4) At the time of transition (when the difference between the current temperature and the target temperature is large), proportional valve control is performed according to the speed of change of the current temperature.

(5) At the time of settling (when the difference between the current temperature and the target temperature is small), the output power of the lamp heater 108 (in particular, an integral component that is not easily affected by disturbance such as a temperature detection error) is referred to. The proportional valve is controlled so that this falls within a predetermined appropriate output range. At that time, when the output power goes out of the appropriate output range, the proportional valve is operated according to the magnitude of the deviation between the two.

(6) At the time of settling (when the difference between the current temperature and the target temperature is small), the overshoot is quickly suppressed and the settling time (from the time when the current temperature reaches the target temperature, even when load disturbance is applied, That is, even if the process is started in the vacuum chamber, the process enters the ready state in order to shorten the stable state (hereinafter, referred to as the ready state) in which the current temperature can be favorably maintained at the target temperature. In the initial stage, the control gain is made higher than usual to increase the responsiveness of the proportional valve.

(7) There is a function of suppressing hunting due to the characteristics of the proportional valve.

(8) A flow rate characteristic of a proportional valve that is specifically used is automatically detected, a parameter suitable for the proportional valve is determined, and an automatic tuner that applies the parameter to a proportional valve characteristic compensation table is used. Function.

The following new items are also employed in the output control of the lamp heater 108 performed by the lamp controller 132.

(9) In the initial stage before the transition to the ready state at the time of transition and settling, the overshoot is suppressed to a small value by adopting the speed type I-PD control and setting the gain to be high. After the ready state is reached, the gain is set lower to ensure stability.

Hereinafter, these new items will be described in order.

FIG. 7 shows the overall flow of the proportional valve control performed by the valve controller 131.

As shown in the drawing, a transient / settling determination (step 141) is performed. As a result, if it is determined that the transient is occurring, the proportional valve control operation during the transient is performed (step 142). Valve control at the time (step 143)
Execute In the transient proportional valve control (step 142), a control calculation is performed on the deviation between the change speed of the current temperature of the working fluid and a predetermined target value (target conversion speed) for the change speed. On the other hand, in the proportional valve control at the time of settling (step 143), the output power of the lamp heater 108 (reference lamp output) fed back from the lamp control (step 149) performed by the lamp controller 132.
And a control calculation is performed on the deviation between the predetermined and the appropriate lamp output width.

In both the transient state and the settling time, the operation result 144 of the proportional valve control indicates the operation amount of the cooling capacity of the heat exchanger 106 (the difference between the current cooling capacity and that after the operation). Next, a table (heat exchanger compensation table) for compensating for the non-linear cooling characteristic of the heat exchanger 106 is applied to the cooling capacity operation amount 144 (step 145). The resulting numerical value 146 indicates the manipulated variable for the coolant flow rate (the difference between the current coolant flow rate and that after the operation). This cooling water flow manipulated variable 1
Next, a table (proportional valve compensation table) for compensating for the non-linear flow characteristics of the proportional valves 112 and 114 is applied (step 147). Note that, here, two types of proportional valve compensation tables adapted to the respective characteristics may be applied to the two proportional valves 112 and 114, but in practice, in order to simplify the processing. In addition, a proportional valve 1 for the main path, which requires more precise control
One type of table adapted to the characteristics of 12
12, 114 can be applied. The numerical value 148 finally obtained by the above control processing is used for the proportional valves 112 and 11.
4 shows the operation amount (the number of pulses to be applied to the motor driver for driving each valve, and the difference between the current pulse number position and that after the operation).

FIG. 8 shows the flow of one example of the method of the transient / settling judgment shown in step 141 of FIG.

As shown in the figure, when the temperature adjustment of the working fluid is started (step 151), first, the current temperature (PV) of the working fluid is compared with a predetermined target temperature (SV) (step 152). If they match, it is determined that it is time to settle, and the control enters the proportional valve control operation (step 143) as described above. On the other hand, if the current temperature (PV) is different from the target temperature (SV), it is determined that the current time is a transitional time, and the process proceeds to the proportional valve control operation at the time of the transient time (step 142) as described above.

The proportional valve control operation during the transition (step 14)
While performing 2), the current temperature (PV) is periodically compared with a predetermined target temperature (SV) (step 15).
3) While the current temperature (PV) has not reached the target temperature (SV), it is determined that the current temperature (PV) is still in the transient state, and the proportional valve control operation (step 142) in the transient state is continued, and the current temperature (P) is reached.
V) reaches the target temperature (SV), it is determined that settling has occurred, and the proportional valve control operation during settling (step 14)
Enter 3).

FIG. 9 shows the flow of another example of the transient / settling judgment method.

As shown, when the temperature adjustment of the working fluid is started (step 161), first, the current temperature (PV) of the working fluid is compared with a predetermined target temperature (SV) (step 162). If they match, it is determined that it is time to settle, and the control enters the proportional valve control operation (step 143) as described above. On the other hand, if the current temperature (PV) is different from the target temperature (SV), it is determined that the current time is a transitional time, and the process proceeds to the proportional valve control operation at the time of the transient time (step 142) as described above.

The proportional valve control operation during the transition (step 14)
While performing 2), it is periodically determined whether the temperature of the working fluid is increasing or decreasing and whether the target temperature (SV) is 40 ° C. or more (step 163). Where 40 ° C
It is determined as a rough guide, depending on whether the temperature of the working fluid is higher or lower than that, whether or not the change in the flow rate of the cooling water has a particularly large effect on the temperature change of the working fluid. This is a threshold. If the result of this determination is that the temperature is falling and the target temperature (SV) is equal to or higher than 40 ° C., the time required for the current temperature (PV) to reach the target temperature (SV) is calculated as the current temperature (PV). ) Is estimated from the current change speed, and it is determined whether the estimated required time is equal to or longer than 60 seconds (step 164). Here, 60 seconds is a value determined as an approximate expected value of a delay time from when the operation of the proportional valve is stopped to when the effect actually appears at the temperature of the working fluid. As a result of the determination, if the required arrival time is 60 seconds or more, it is determined that the time is still a transition, and the proportional valve control operation during the transition (step 142) is continued. afterwards,
If the required arrival time is less than 60 seconds, the process proceeds to step 166, in which the operation of the proportional valve is stopped until the current temperature (PV) reaches the target temperature (SV) (step 166). When the temperature reaches the target temperature (SV), it is determined that the set time has come, and the proportional valve control operation at the time of settling (step 143) is started. As described above, when the temperature is falling and the target temperature (SV) is equal to or higher than 40 ° C., at the point of time 60 seconds before the current temperature (PV) reaches the target temperature (SV), the transition time is quickly changed. The reason why the control is rounded up and the operation of the proportional valve is stopped until the time of settling is reached is to effectively reduce the amount of overshoot (that is, undershoot) which tends to occur particularly when the temperature is lowered with a large cooling capacity.

On the other hand, if the result of determination in step 163 is that the temperature is rising or that the target temperature (SV) is less than 40 ° C., the flow proceeds to step 165 and, as in the method example shown in FIG. As long as the current temperature (PV) has not reached the target temperature (SV), it is determined that the current temperature (PV) is still in the transient state, and the proportional valve control operation (step 142) during the transient is continued, and the current temperature (P
V) reaches the target temperature (SV), it is determined that settling has occurred, and the proportional valve control operation during settling (step 14)
Enter 3).

FIG. 10 shows the flow of the proportional valve control at the time of transition shown in step 142 in FIGS.

In the transient proportional valve control, the temperature (PV) of the working fluid is raised or lowered at a constant speed toward the target temperature. As shown in the drawing, the change speed of the current temperature (PV) of the working fluid is obtained, the deviation between the change temperature and a predetermined target change speed is calculated (step S171), and the deviation of the change speed is calculated in a predetermined cycle (for example, 250 ms). ) (Step 172), and a PI operation (or PID operation) is performed on the sampled deviation using a predetermined control gain (Kp) (step 173). The result of this calculation indicates the amount of operation of the cooling capacity of the heat exchanger 106 (the difference between the current operation and after the operation). Then, it is determined whether the temperature is currently increasing or decreasing (step 174). When the temperature is increasing, the cooling capacity is increased with respect to the manipulated variable obtained by the PI calculation (the proportional valve of the main path). The amount of operation in the direction of opening (112) is cut to reduce the cooling capacity (proportional valve 112).
Is applied (step 175). When the temperature is decreasing, the cooling capacity is reduced with respect to the manipulated variable obtained by the PI calculation (the proportional valve 1).
The amount of operation in the direction of closing (12) is cut, and a filter is passed to pass only the amount of operation in the direction of increasing the cooling capacity (opening the proportional valve 112) (step 176). Next, regardless of whether the cooling capacity is increased or decreased with respect to the operation amount passed through the filter, the operation amount having an absolute value larger than a predetermined limit value is cut, and the operation amount having an absolute value equal to or less than the limit value is cut. A limiter that passes only the light is applied (step 177). The amount of operation through the limiter is the amount of operation of the cooling capacity that is finally output.

Here, the target change speed is determined by the lamp heater 1
08 is set to a value almost equivalent to the response speed of the temperature control by the temperature control. Due to the delay due to the heat capacity of the heat exchanger 108 and the like, even after the current temperature reaches the target temperature, the temperature change due to the transient control that has been performed immediately before the target temperature is gradually and continued. If the target change speed is substantially equal to the response speed of the temperature control by the lamp heater 108, even if the temperature change continues at the same speed after reaching the target temperature, the temperature change is suppressed by the output control of the lamp heater 108. Can be. Control gain (Kp)
Is set to a smaller value. As a result, the proportional valve is gently operated, and excessive operation of the proportional valve (excessive opening / closing, that is, excessive cooling / cooling) is suppressed.

The filters in steps 175 and 176 mean that the proportional valve operation is not returned even if the proportional valve operation is slightly overdriven. In order to maintain a constant temperature rise or fall, it is necessary in principle to continue to operate the proportional valve in one direction. In other words, when maintaining the temperature rise at a constant speed, the cooling capacity increases as the working fluid temperature increases at the same cooling water flow rate, so it is necessary to continue the operation of reducing the cooling water flow rate (closing the proportional valve 112). is there.
In addition, when the temperature is decreased at a constant rate, the cooling capacity decreases with the decrease in temperature at the same cooling water flow rate, so it is necessary to continue the operation of increasing the cooling water flow rate (opening the proportional valve 112). Therefore, even when the operation of closing the proportional valve 112 is slightly excessive during the temperature rise, or when the operation of opening the proportional valve 112 is slightly excessive during the temperature decrease,
The overrunning operation will coincide with the proper amount of operation after some time. Therefore, even if the operation of the proportional valve is somewhat excessive, it is better not to return the operation, but rather smooth control can be performed.

The purpose of the limiter in step 177 is to prevent an extremely large cooling capacity operation that cannot be handled by the output capacity of the lamp heater 108. Therefore, the limit value of the limiter is set to a cooling capacity operation amount (cooling amount difference / second) corresponding to 100% output power (for example, 3 kW) of the lamp heater 108.

FIG. 11 shows the flow of the proportional valve control at the time of settling shown in step 143 in FIGS.

The proportional valve control during settling is performed by the lamp heater 10.
The proportional valve is operated to control the amount of cooling water so that the output of 8 falls within a predetermined appropriate range. As shown, the reference lamp output fed back from the lamp controller 132 (see FIG. 6) is compared with an appropriate output range having a predetermined lower limit value UL and an upper limit value UH, and the reference lamp output falls below the lower limit value UL. The difference between the reference lamp output and the lower limit value UL,
H, the reference lamp output and the upper limit U
When the reference lamp output falls within this proper output range, a deviation from H is output (step 181). This deviation is calculated for a predetermined period (for example, 2
(50 ms). Then, it is determined whether or not it is currently in the ready state (step 183).
Here, the ready state means that after the current temperature (PV) reaches the target temperature (SV), a predetermined amount of heat (for example, 1.5 kW when the target temperature is 40 ° C. or higher, and when the target temperature is lower than 40 ° C.). Is 1 kW), the current temperature (P
V) to the target temperature (SV) by a predetermined accuracy (for example, ± 1).
° C). A specific method of determining the ready state will be described later.

As a result of the ready determination, if the ready state has not yet been reached, a PI calculation (or PID calculation) using a relatively large value of the control gain (Kp1 / TI) is performed on the sampled deviation ( Step 184) If it is in the ready state, the control gain (Kp2 / T
I) Perform a PI operation using (for example, half the value of Kp1 / TI) (step 185). The result of the PI calculation indicates the amount of operation of the cooling capacity of the heat exchanger 106 (difference between the current time and after the operation). Next, the cooling capacity operation amount is set in step 17 already described in the transition control in FIG.
The same limiter as in Step 7 is applied (Step 186). The amount of operation through the limiter is the amount of operation of the cooling capacity that is finally output.

As the above-described reference lamp output, the I (integral) component of the P, I, and D components obtained by the PID calculation in the lamp controller 132 is used in principle. This is because the integral component is hardly affected by disturbance such as a temperature detection error (reacts to an external load disturbance), and represents the current cooling amount of the cooling water closest. However, as described later, the PID control method of the lamp control is different before and after the ready state, and the position-type PID control is performed after the ready state, so that the integral component is independently extracted. However, since the speed type I-PD control that easily suppresses the overshoot is performed before the ready state is reached, the integral component cannot be taken out independently. Therefore, the integral component is used as the reference lamp output only after the ready state, and before the ready state,
A value including all components of P, I, and D is used.

The proper output range of step 181 (lower limit U
L and the upper limit UH) are, for example, 30% output power of the lamp heater 108 (for example, 0.9 kW),
Upper limit UH is 60% output power (for example, 1.8 kW)
Is set to a value corresponding to. Lamp output is lower limit U
L or more, the expected maximum amount (for example, 1.5 k
Even if a load disturbance of (W) occurs (that raises the working fluid temperature), the target temperature can be maintained at a predetermined accuracy (for example, ± 1 ° C.) only by controlling the lamp output until the proportional valve responds. In state. Then, the lower limit value UL and the upper limit value U
The difference in H (the width of the appropriate output range) is determined by the fact that during the delay time from when the proportional valve operation is performed to when the working fluid temperature actually changes, the proportional valve operation is further advanced and the lamp output fluctuates too much. Proportional valve operation is returned to correct it to
This is also set for the purpose of preventing the occurrence of hunting, such as the lamp output going back in the opposite direction due to the return due to the delay time. That is, the width of the appropriate output range is set to an appropriate width (for example, 30% lamp output) for the purpose of preventing hunting by preventing the proportional valve control from reacting to fluctuations in the lamp output within the width. (The smaller the width, the higher the possibility of hunting). Although not shown in FIG. 11, in the proportional valve control at the time of settling (particularly, control before the ready state is reached), if a hunting occurs, a process for suppressing the hunting is performed by reducing the control gain. Are added, and the hunting suppression processing will be described later.

The control gains (Kp1 / TI, Kp2 / TI) in steps 184 and 185 are set within a range that the lamp control can follow. That is, if the control gain is too high, the lamp control cannot follow, and the working fluid temperature fluctuates too much during the operation of the proportional valve. Therefore, the control gain is set within a range that is not too high. The proportional gain (Kp1) before entering the ready state is set relatively high, whereby the response of the proportional valve becomes faster and overshoot is easily suppressed. On the other hand, the proportional gain (Kp2) after the ready state is set relatively low, whereby the response of the proportional valve is slowed and the control is stabilized. The integration time TI is set to a value roughly corresponding to the time constant of the temperature change in the heat exchanger 106.

FIG. 12 shows the function of the heat exchanger compensation table used in step 145 of FIG.

As shown, the heat exchanger compensation table 19
0 is the nonlinear cooling characteristic (Pcx) of the heat exchanger 106
And has a function of converting the manipulated variable of the cooling capacity into the manipulated variable of the cooling water flow rate. The characteristic (Pcx-1) of the heat exchanger compensation table 190 is a function of the current temperature (PV) of the working fluid. That is,
Depending on the working fluid temperature (PV), the cooling water flow rate manipulated variable for the same cooling capacity manipulated variable varies. On the heat exchanger compensation table 190, the cooling capacity operation amount is defined, for example, as a ratio [%] to the rated output power of the lamp heater 108. The operation amount of the cooling water flow rate is a ratio (for example, 1%) of the flow rate of the cooling water flowing through the heat exchanger 106 to the total flow rate of the cooling water (a constant value, for example, 10 L / min).
= 100 cc / min). The characteristic (Pcx-1) of the heat exchanger compensation table 190 is
Is determined based on the actual measurement result or calculation result of the characteristic (Pcx).

FIG. 13 shows a specific example of the characteristic (Pcx-1) of the heat exchanger compensation table 190.

In FIG. 13, the horizontal axis indicates the working fluid temperature (PV). The vertical axis represents the manipulated variable of the cooling water flow rate (total flow rate (for example, 10 L / mi) required to generate a cooling capacity equivalent to 100% lamp output (for example, 3 kW).
n)). A solid line graph 191 in the figure shows the set values of the table 190 (the characteristics (Pcx-1) of the table 190). In addition, the plot of the circular dot and the plot of the square dot show the lowest value of 15 ° C. and the highest value of 3 for the cooling water temperature, respectively.
This shows the reverse characteristic of the actual characteristic (Pcx) of the heat exchanger 106 when the temperature is 0 ° C.

As shown in the figure, the set values in the table 190 substantially correspond to the characteristics (Pcx) of the heat exchanger 106 when the cooling water temperature is the minimum value of 15 ° C. Table characteristics (Pcx-1), cooling water temperature is the lowest value 15
C., the reason is that when the cooling water temperature is at the lowest value of 15 ° C., the heat exchanger 106 exhibits the greatest cooling capacity, and therefore the highest precision is required for the proportional valve control. This is because that. The higher the cooling water temperature, the more coarsely the proportional valve control can be performed.

By using this table 190, the cooling water flow rate operation amount can be obtained from the cooling capacity operation amount as follows. For example, the current temperature (PV) of the working fluid
Is 50 ° C., the cooling capacity operation amount is calculated to be 10%. According to this table 190, when the current temperature (PV) is 50 ° C., the cooling water flow rate operation amount for generating 100% cooling capacity is 15%. Therefore, 1
The cooling water flow operation amount corresponding to the cooling capacity operation amount of 0% is 1.5%. Here, since the operation amount of the cooling water flow rate of 100% is 10 L / min, the operation amount of the cooling water flow amount of 1.5% is 0.15 L / min.

FIG. 14 shows the function of the proportional valve compensation table used in step 147 of FIG.

As shown, the proportional valve compensation table 200
Has a characteristic (Pcv-1) which is almost opposite to the non-linear flow characteristic (Pcv) of the proportional valve, and the operation amount of the cooling water flow is
It has a function to convert to the operation amount (number of pulses) of the proportional valve. The characteristic (Pcv-1) of the proportional valve compensation table 200 is a function of the current position (current pulse number position) (PL) of the proportional valve. That is, the proportional valve operation amount for the same cooling water flow amount operation amount differs depending on the proportional valve position (PL).
On the proportional valve compensation table 200, the cooling water flow operation amount is
For example, the total flow rate of the cooling water (a constant value, for example, 10
(L / min) of the cooling water flowing through the heat exchanger 106 (for example, 1% = 100 cc / min). The proportional valve operation amount is the number of pulses (relative value from the current position) to be added to open or close the valve further from the current position. Characteristics of proportional valve compensation table 200 (P
cv-1) is determined based on the actual measurement results of the characteristics (Pcv) of many proportional valves of the same model.

FIG. 15 shows the results of actually measuring the characteristics of a large number of proportional valves of a certain model.

In FIG. 15, the horizontal axis represents the pulse number position (absolute value with the fully closed state as the origin) of each proportional valve, and the vertical axis represents the pressure loss (Cv value) of each proportional valve. ing. The characteristic curve 201 of the solid line in the figure shows the characteristic curve of the measured many proportional valves which is shifted to the leftmost side in the figure, and the characteristic curve 202 of the dotted line is the characteristic curve of the measured characteristic of many proportional valves. Among them, the one shifted to the rightmost in the figure is shown. The characteristic curves of the other proportional valves are two characteristic curves 2 shown in the figure.
01, 202 existed.

It is understood from the actual measurement results that the characteristic curves of all the proportional valves have substantially the same shape as the characteristic curves 201 and 202 shown in FIG. (Position of the number of pulses). Therefore, it can be said that the individual difference in the flow characteristic of the proportional valve is substantially only the position shift in the horizontal axis direction in the figure. As shown by the shapes of the characteristic curves 201 and 202 shown in the drawing, when pulses are applied from the fully closed state, the Cv value remains zero for a while, but at a certain pulse number position 20.
At 3, 204, the Cv value rises suddenly. In this specification, the pulse number positions 203 and 204 are referred to as a “first sudden change portion” of the proportional valve characteristic. As more pulses are added, the first
Although the Cv value is almost constant for a while after the sudden change, the Cv value starts to increase at certain pulse number positions 205 and 206.
The positions 205 and 206 are referred to as “second suddenly changing portions” of the proportional valve characteristic in this specification. From the second sudden change section, the Cv value also increases as the number of pulses increases.

FIG. 16 shows the characteristics (Pcv-Pc-V) of the proportional valve compensation table 200 created based on the measured characteristics shown in FIG.
An example of 1) is shown below.

In FIG. 16, the horizontal axis indicates the pulse number position of each proportional valve when the first sudden change portions 203 and 204 of each proportional valve shown in FIG. 15 are used as the origin. The vertical axis indicates the cooling of the main path caused by moving the proportional valve 112 of the main path by one pulse from the position of each pulse under the condition that the Cv value of the bypass path is constant (for example, = 1.5). The amount of change in water flow rate is shown. The change amount of the vertical axis is a ratio [%] to the total flow rate of the cooling water (for example, 10 L / min).
(For example, 1% = 0.1 L / min).
A thin solid line characteristic curve 207 in the figure corresponds to one of the actually measured characteristic curves 201 and 202 shown in FIG. Since the positions of the pulse numbers of the first sudden change portions 203 and 204 are set as the origin of the horizontal axis, individual differences in the proportional valve characteristics are removed, and therefore, the characteristics of all the proportional valves are represented by the characteristic curve 2
07 is almost the same. In the characteristic curve 207, a part 208 is a first sudden change part, and a part 109 is a second sudden change part. A characteristic curve 210 indicated by a thick solid line in the figure is a set value of the proportional valve compensation table 200, that is, the proportional valve compensation table 2
00 (Pcv-1). The set value 210 of the proportional valve compensation table 200 has a simple shape for convenience of mechanical processing, but is substantially the same as the actual characteristic 207 of all proportional valves from which individual differences have been removed.

As is clear from the above description, the set value 210 of the proportional valve compensation table 200 represents a common part obtained by removing the individuality (individual difference) from the characteristics of all the proportional valves of the same model. Can be commonly applied to all the proportional valves. Here, the individuality (individual difference) of each proportional valve is typically reflected on the absolute pulse position of the first sudden change section 203, 204 of each proportional valve shown in FIG. Therefore, in the proportional valve compensation table 200, the individuality of each proportional valve (for example,
Numerical values representing the absolute pulse positions of the first sudden change units 203 and 204) can be taken as parameters. In addition, other device characteristics (such as pressure loss) that affect the specific characteristics of the proportional valve can also be captured as parameters. The pulse number position (the number of pulses shown in FIG. 16) of the table 200 is shifted by the number of pulses corresponding to the fetched parameter, so that the characteristic of the proportional valve compensation table 200 matches the individuality of each proportional valve. . The above parameters are automatically determined by performing auto tuning described later.

By using the above-described heat exchanger compensation table 190 and proportional valve compensation table 200 in combination at the subsequent stage of the proportional valve control processing as shown in FIG. 7, the nonlinear cooling characteristic of the heat exchanger and the proportional The non-linear flow characteristics of the valve can be well compensated. Therefore, in the proportional valve control processing, it is not necessary to consider the non-linear characteristics of the heat exchanger and the proportional valve. Further, when the specific model of the element of the proportional valve or the heat exchanger to be used is changed, it can be dealt with by changing only the corresponding table. Further, since the heat exchanger compensation table 190 and the proportional valve compensation table 200 can be easily formed from the actual characteristics of the proportional valve and the heat exchanger, highly accurate ones can be obtained.

In the proportional valve compensation table 200, the pulse number position is not defined by the absolute pulse number with the fully closed position as the origin, but by the relative pulse number with the first sudden change portion of each proportional valve as the origin. And the individuality of each proportional valve,
The characteristics of the equipment environment in which the proportional valve is used (e.g., pressure drop in piping) can be taken as a parameter and adapted to it. Therefore, there is no longer a wide margin in which individual differences are taken into account as in the conventional case, and control responsiveness is improved as compared with the conventional case. Also, the proportional valve compensation table 200
Then, the flow rate is not defined as an absolute flow rate at each pulse number position, but is defined as a relative value of what percentage of the total flow rate changes when one pulse moves at each pulse number position. It is robust against changes in proportional valve characteristics.

As shown in FIG. 4, the proportional valve 112 of the main passage 113 and the proportional valve 11 of the bypass passage 115
4 and for each of the two proportional valves 112, 114, another proportional valve compensation table adapted to each can be applied. However, in practice, the main road 1
By applying one proportional valve compensation table adapted to the thirteen proportional valves 112 to not only the proportional valve 112 of the main path 113 but also the proportional valve 114 of the bypass path 115, the processing may be simplified. . One of the reasons is that the operation of the constant flow valve 117 shown in FIG.
Regardless of the combined pressure drop, 12, 114, the overall flow rate of the cooling water is always constant, and the two proportional valves 11
This is because the operations 2 and 114 can be performed one by one, and when one is operated, the other is fully opened. Another reason is that, for most of the variable range of the target temperature (SV), only the proportional valve 112 of the main path 113 is operated for controlling the cooling capacity. The proportional valve 114 of the bypass 115 is operated only in a part of the region where the SV is low.
This is because the operation of the proportional valve in that region is sufficient with a coarse resolution, and a high-definition operation is not required.

FIG. 17 shows a process flow of the ready determination shown in step 183 in the proportional valve control at the time of settling in FIG.

As shown, when the temperature adjustment operation of the working fluid is started (step 211), first, it is determined whether or not the current temperature (PV) of the working fluid has reached the target temperature (SV) (step 211). Step 212). Before reaching the target temperature (SV), the above-described proportional valve control at the time of transition is performed, so there is no room for performing a ready determination. Current temperature (PV)
Is passed through the target temperature (SV), the proportional valve control at the time of settling described above is started. When the proportional valve control at the time of settling is started, it is determined whether the overshoot is over (step 214) after waiting for a time (for example, 1 second) during which the proportional valve control reliably starts operating (step 213). ),
Wait until overshoot is over. When the overshoot is over, a ready judgment (step 183) is started.

When the ready judgment is started, first, it is judged whether the control at the time of the transition before that was the temperature rise or the temperature decrease (step 215). If the temperature is lowered during the transition,
At the end of the overshoot, the lamp output has a large value because the overshoot (that is, undershoot) has been suppressed until now (the lamp output is more reliable than the lower limit UL of the appropriate lamp output range shown in FIG. 11). Is large). Therefore, even if a load disturbance occurs immediately, the lamp output can be reduced to sufficiently absorb the load disturbance, and it is immediately determined that the ready state has been established (step 219).

On the other hand, if the result of determination in step 215 is that the temperature is being raised during a transition, the lamp output has a low value at the time when the overshoot ends because the overshoot has been suppressed so far. (There is a possibility that it is smaller than the lower limit value UL of the appropriate lamp output range shown in FIG. 11). In this case, if the working fluid is cooled to some extent by the cooling water and the lamp output is raised to the lower limit UL or more by that amount, the ready state is not established. Therefore, first, in step 216, it is determined whether or not the pulse number position of the proportional valve 112 on the main path is equal to or larger than the second sudden change portion (see FIG. 15).
The pulse number position of the proportional valve 112 is less than the second sudden change part (FIG. 15).
In this case, the proportional valve 112 cannot be opened immediately (even if a load disturbance occurs, the proportional valve 112 cannot react immediately). Therefore, in that case, it is determined whether the lamp output U is higher or lower than the lower limit value UL (step 217), and it is determined that the lamp output U has reached the ready state after waiting until the lamp output U becomes higher than the lower limit value UL. (Step 219).

On the other hand, if the result of the determination in step 216 is that the pulse number position of the proportional valve 112 is at or above the second sudden change portion (on the right side of the second sudden change portion in FIG. 15), the proportional valve 112 can be opened immediately. The proportional valve 112 can be used even if a load disturbance occurs.
Can react immediately. Therefore, in that case, it is determined whether or not the lamp output U has exceeded a value slightly lower (for example, 10%) than the lower limit value UL (step 219). When the value approaches the value UL (as soon as possible), it is determined that the ready state has been reached (step 219).

As described above, by judging whether or not the apparatus is in the ready state from various states of the apparatus such as the lamp output, the temperature change, and the opening degree of the proportional valve, the state of the apparatus is immediately changed to the ready state. Thus, it is possible to determine that the vacuum chamber is ready, and the process of the vacuum chamber can be started quickly without wasting time.

FIG. 18 shows a flow of the hunting suppression processing performed in the proportional valve control at the time of settling (particularly, control before the ready state is reached).

The hunting here means a state in which the lamp output fluctuates beyond the above-described proper lamp output range (lower limit value UL and upper limit value UH) due to the operation of the proportional valve. When hunting occurs, the proportional valve repeats opening and closing operations in a short time to suppress the hunting. Therefore, hunting can be detected by detecting such an operation of the proportional valve.

As shown in FIG. 18, when the operation of adjusting the temperature of the working fluid is started (step 211), a transient / settling judgment is made (step 212).
The above-described proportional valve control at the time of settling (not shown in FIG. 18) is started, and the hunting suppression processing is started (step 213). In the hunting suppression processing, first, the result of the above-described ready determination is referred to (step 214).
As a result, if the state is already in the ready state, there is no longer a risk of occurrence of hunting, and the hunting suppression processing is ended.

If the result of determination in step 214 is that the hunting has not yet occurred, it is next determined whether or not hunting has occurred (step 215). here,
For example, it is checked whether or not the setting of the opening and closing of the proportional valve has been repeated three or more times within the last 60 seconds, and if so, it is determined that hunting has occurred (step 216). If hunting has occurred, the proportional gain (Kp) of the control is reduced by half (that is, reduced to the same value as the control gain in the ready state (the value of the block 185 in FIG. 11)) in order to suppress the hunting. ) (Step 217).

Thereafter, the flow returns to step 214. If there are still three or more opening / closing operations in 60 seconds in step 215, it is determined that hunting is continuing (216).
The proportional gain (Kp) is further reduced to half of the current value (step 217). Thus, until hunting converges
The proportional gain (Kp) is reduced. Hunting converges (less than 3 times in step 215) and step 2
When the ready state is reached in step 14, there is no longer a risk of hunting, so the proportional gain (Kp) is set to the prescribed value in the ready state (the value of block 185 in FIG. 11) (step 218), and this hunting suppression processing is performed. To end.

As described above, the valve controller 131 (see FIG. 6)
Has been described in general. Next, the lamp controller 132 (see FIG. 6)
Will be described.

FIG. 19 shows the overall flow of the control of the lamp heater 108 performed by the lamp controller 132.

As shown in the figure, when the operation of adjusting the temperature of the working fluid is started (step 231), first, a control gain (Kp) for the PID control is set to a predetermined large gain value (step 232). Control gain (K
p) to control the lamp output by the speed type I-PD control method (step 233). At the start of the temperature adjustment, it is usually a transition. Therefore, the ramp control during the transition is performed by a speed-type I-PD control method using a large control gain (Kp). When the state shifts from the transition to the settling, the ready determination 234 is performed as described above. As a result, the speed-type I-PD control using the large control gain (Kp) is continued while not yet in the ready state. Thereafter, when a ready state is established, the control gain (Kp) is switched to a predetermined small value (for example, half of the initial gain value) (step 235), and the control method is switched to position-type PID control, and the position-type PID control is switched. PID
The lamp output is controlled by the control method (step 23).
6).

In this manner, the ramp control is performed by the speed-type I-PD control method using a large control gain from the time of the transition to the time of reaching the ready state at the time of settling. After that, the position-based PID control using a small control gain is performed. This allows
Before reaching the ready state, the amount of overshoot can be kept small, and after reaching the ready state, control can be stabilized.

FIG. 20 shows the flow of ramp control by the speed type I-PD control method, and FIG. 21 shows the flow of ramp control by the position type PID control method.

Since the methods of the speed type I-PD control and the position type PID control are well known to those skilled in the art, their description is omitted here. The reference lamp output sent to the proportional valve control at the time of settling is, as described above, when the speed type I-PD control of FIG.
Since only the I component cannot be extracted, P, I, D
On the other hand, when the position type PID control of FIG. 21 is performed after the ready state is reached, only the I component having the value closest to the current cooling amount by the cooling water is used.

FIGS. 22 and 23 show specific changes in the current temperature (PV) of the working fluid and changes in the lamp control and the proportional valve control over time. FIG. 22 shows the case when the temperature rises, and FIG. 23 shows the case when the temperature falls.

In these figures, a thick solid line curve indicates a change in the current temperature (PV), a thick one-dot chain line curve indicates a change in the proportional valve opening, and a thick two-dot chain line curve indicates a change in the lamp output.

As shown in FIG. 22, when the temperature is raised, from the start of the temperature adjustment to time t1 when the current temperature (PV) reaches the target temperature (SV), the proportional valve control during the transition is performed.
Proportional valve control at the time of settling is performed from time t1. Time t
Overshoot occurs from 1 and ends at time t2 when the current temperature (PV) returns to the target temperature (SV) again. Thereafter, at time t3 when the lamp output rises and reaches the lower limit value UL of the appropriate lamp output width, it is determined that the ready state has been reached, and the lamp control switches from the large gain I-PD control to the small gain PID control. Also, the gain of the proportional valve control at the time of settling is switched from a large value to a small value.

As shown in FIG. 23, when the temperature is lowered, the transient state continues from the start of the temperature adjustment to time t2 when the current temperature (PV) reaches the target temperature (SV), but 60 seconds before the transition. Is the current temperature (PV) and the target temperature (SV)
Is reached at the predicted time t1, the proportional valve control in the transient state ends, and thereafter the proportional valve is not operated until time t2. Proportional valve control during settling is performed from time t2.
Overshoot occurs from time t2, and the current temperature (P
At time t3 when V) returns to the target temperature (SV) again, it is determined that the overshoot is over, and at the same time it is determined to be ready, and the lamp control is switched from large gain I-PD control to small gain PID control. The gain of the proportional valve control during settling also switches from a large value to a small value.

The description of the control at the time of ordinary temperature adjustment is completed. Lastly, a description will be given of an auto-tuning process for adapting the proportional valve compensation table to specific characteristics of the proportional valve.

FIG. 24 shows the overall flow of the auto tuning process.

In the auto-tuning, the lamp output is controlled so as to control the working fluid temperature to a predetermined target temperature, and the proportional valve 112 on the main path is operated by a fixed number of pulses, and the fluctuation of the lamp output due to the operation is controlled. By monitoring, the position of the pulse number of the first sudden change portion of the proportional valve 112 is detected, and this is used as a parameter for the proportional valve compensation table 200.
The characteristic of the proportional valve compensation table 200 is adapted to the personality of the proportional valve 112 by setting. This automatic tuning process can be performed at any time as needed.

As shown in FIG. 24, when the automatic tuning process is started (step 271), first, the proportional valves 112 and 114 on both the main path and the bypass path are fully opened (step 272), and the pump 103 is operated. The working fluid and the cooling water are allowed to flow (step 273), and after waiting for one minute in that state (step 276), when the flow is stabilized, the current temperature (PV) of the working fluid is set to a predetermined low temperature region (for example, 40 ° C. or lower). It is checked whether or not it has entered (step 275). If the current temperature (PV) is 40 ° C. or lower, the flow rate of the working fluid is measured (step 276), and a PID constant for lamp control is set based on the flow rate value (step 277). Here, the current temperature (PV) is 4
To measure the flow rate of the working fluid after the temperature drops below 0 ° C,
Due to the characteristics of the flow rate sensor, the higher the working fluid temperature, the lower the flow rate is measured as compared to the actual flow rate.

Thereafter, the proportional valve 112 of the main road to be measured is fully closed (step 278), the ramp control system is set to the position type PID control (step 279), and the target temperature (SV) is raised to a predetermined high temperature (step 279). For example, the temperature is set to 80 ° C. (Step 280), and the temperature is raised (Step 28).
1). When it is confirmed that the current temperature (PV) of the working fluid has reached the target temperature (SV) (for example, 80 ° C.) (Step 282), a proportional valve flow characteristic tuning process is performed (Step 283). The proportional valve flow rate characteristic tuning process is to monitor the fluctuation of the lamp output while operating the proportional valve 112 of the main path at a predetermined number of pulses (for example, 10 pulses).
This is a process of determining the pulse number position of the sudden change portion and setting it as a parameter in the proportional valve compensation table. Here, the reason why this proportional valve flow rate characteristic tuning process is performed under a high temperature target temperature (SV) such as 80 ° C. This is because the amount of heat radiation increases, so that the working fluid temperature can be controlled to the target temperature constant only by lamp control even when the proportional valve is fully closed (that is, without cooling).

When the proportional valve flow characteristic tuning process is completed, the automatic tuning process is completed (step 2).
84), the target temperature (SV) is returned to the original value before the start of the auto-tuning process (step 285), and then the normal operation is started (step S286).

FIG. 25 shows the flow of the proportional valve flow characteristic tuning processing shown in step 283 in FIG.

As shown in the drawing, first, 120 pulses are applied to the proportional valve 112 in the fully closed state of the main path, and the proportional valve 1
12 is the absolute pulse number position of 120 pulses (V
P) (S291). Then, the operation is continued for one minute without operating the proportional valve 112 (step 293), and the fluctuation amount of the lamp output is integrated and recorded (that is, the fluctuation amount of the integral component of the position-type PID control during the one minute is calculated). Record) (step 292). After one minute has passed, another 10 pulses are applied to the proportional valve 112,
The absolute pulse number position (VP) of the proportional valve 112 is advanced by 10 pulses (step 296). And, similarly,
The operation is continued for one minute without operating the proportional valve 112 (step 293), and the fluctuation amount of the lamp output is integrated and recorded (step 292).

As described above, the absolute position (V
Starting from P), the operation of opening the proportional valve 112 at 10-pulse intervals and integrating and recording the lamp output fluctuation amount at that position for one minute is repeated. This operation is performed by the proportional valve 112.
Is performed until the absolute position (VP) of the lamp reaches 270 pulses (step 294), the integrated values of the lamp output fluctuation amounts recorded at the respective absolute positions in increments of 10 pulses so far are compared. The determined absolute position (VP) is determined as the first sudden change part, and the absolute position of the first sudden change part is set as a parameter of the proportional valve compensation table 200 (step 297). This completes the proportional valve flow characteristic tuning process.

The embodiment of the present invention has been described above.
The above embodiment is merely an example for describing the present invention, and is not intended to limit the present invention to only the above embodiment. Therefore, the present invention can be implemented in various modes other than the above-described embodiment.

For example, in the above-described embodiment, the proportional valve control has been described by taking the case where the amount of cooling water is controlled by the proportional valve as an example. However, the proportional valve of the present invention is also applicable when the flow rate of the working fluid is controlled by the proportional valve. A valve control method can be applied.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a schematic configuration of a general vacuum chamber used in a semiconductor manufacturing apparatus.

FIG. 2 is a block diagram showing a configuration of a conventional fluid temperature control device (low temperature device) used for temperature control of a low temperature portion of the vacuum chamber of FIG.

FIG. 3 is a block diagram showing the configuration of another conventional fluid temperature control device (high-temperature machine) used for controlling the temperature of the high-temperature portion of the vacuum chamber of FIG.

FIG. 4 is a block diagram showing a mechanical system configuration of the fluid temperature control device according to one embodiment of the present invention.

FIG. 5 is a block diagram showing a configuration of hardware for performing a control operation of the fluid temperature control device 100.

FIG. 6 is a block diagram showing a basic functional configuration of a controller 121.

FIG. 7 is a diagram showing an overall flow of proportional valve control performed by a valve controller 131.

8 is a diagram showing a flow of one example of a method of transient / settling judgment shown in step 141 of FIG. 7;

FIG. 9 is a view showing the flow of another example of the transient / settling judgment method shown in step 141 of FIG. 7;

FIG. 10 is a diagram showing a flow of proportional valve control at the time of transition shown in step 142 in FIGS. 7 to 9;

FIG. 11 is a diagram showing a flow of proportional valve control at the time of settling shown in step 143 in FIGS. 7 to 9;

FIG. 12 is a diagram showing a function of a heat exchanger compensation table used in step 145 of FIG. 7;

FIG. 13 shows the characteristics of the heat exchanger compensation table 190 (Pcx-
The figure which shows the specific example of 1).

FIG. 14 is a view showing the function of a proportional valve compensation table used in step 147 of FIG. 7;

FIG. 15 is a view showing the results of actually measuring the characteristics of a large number of proportional valves of a certain model.

16 is a diagram showing a specific example of a characteristic (Pcv-1) of a proportional valve compensation table 200 created based on the measured characteristics shown in FIG.

FIG. 17 is a diagram showing a process flow of a ready determination shown in step 183 in the proportional valve control at the time of settling in FIG. 11;

FIG. 18 is a diagram showing a flow of a hunting suppression process performed in proportional valve control during settling (particularly, control before a ready state is reached).

FIG. 19 is a diagram showing an overall flow of control of the lamp heater performed by the lamp controller 132.

FIG. 20 is a diagram showing a flow of ramp control by a speed type I-PD control method.

FIG. 21 is a diagram showing a flow of lamp control by a position-type PID control method.

FIG. 22 shows the current temperature of the working fluid (P
The figure which shows the change of V) and the transition of the state of lamp control and proportional valve control.

FIG. 23 shows the current temperature of the working fluid (P
The figure which shows the change of V) and the transition of the state of lamp control and proportional valve control.

FIG. 24 is a diagram showing an overall flow of an automatic tuning process.

FIG. 25 is a diagram showing a flow of the proportional valve flow characteristic tuning processing shown in step 283 in FIG. 24.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 fluid temperature control device 101 working fluid circulation path 106 cooling heat exchanger 108 lamp heater (heating heat exchanger) 107 flow sensor 109 temperature sensor 111 cooling water path 112, 113 proportional valve 117 constant flow valve 121 Controller 131 Valve controller 132 Lamp controller 142 Transient proportional valve control 143 Proportional valve control during settling 190 Heat exchanger compensation table 200 Proportional valve compensation table

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Takumi Sugihara 1200 Manda, Hiratsuka-shi, Kanagawa F-term in Komatsu Ltd. Research Laboratory 3L034 CA05

Claims (14)

[Claims] 1. A heat exchanger for performing heat exchange between a first fluid and a second fluid, wherein the first fluid and the second fluid flow, and at least one of the first and second fluids flowing through the heat exchanger. A flow control valve for controlling the flow rate, and in order to control the heat exchange capacity in the heat exchanger, determine the operation amount of the position of the flow control valve and apply the operation amount of the position to the flow control valve. A valve control unit for controlling the heat exchange capacity of the heat exchanger, wherein the valve control unit calculates an operation amount of the heat exchange capacity, and cooling provided by the heat exchanger. To compensate for the nonlinearity of the characteristic, a heat exchanger compensating means that defines the relationship between the manipulated variable of the heat exchange capacity and the manipulated variable of the flow rate flowing through the flow control valve, and a flow characteristic of the flow control valve And the position of the flow control valve so as to compensate for the nonlinearity of the flow control valve. Flow control valve compensating means that defines the relationship with the operating amount of the device, and using the heat exchanger compensating means and the flow control valve compensating means, from the operating amount of the heat exchange capacity calculated by the calculating means. Means for determining an operation amount of the position to be applied to the flow control valve. 2. The fluid temperature control device according to claim 1, wherein the heat exchanger compensating means and the flow rate control valve compensating means are respectively lookup tables. 3. The flow rate control valve compensating means displays a change amount of the flow rate generated when one unit of the operation amount of the position is applied to each position that the flow rate control valve can take at each position. The fluid temperature control device according to claim 1, wherein the determined relative value is defined. 4. The flow control valve compensating means has a definition of a relationship between an operation amount of the flow rate and an operation amount of the position based on a common flow characteristic that does not depend on an individual difference of the flow control valve, In addition, the personality of the equipped flow control valve is captured as a parameter, and the definition is adjusted to match the personality of the equipped flow control valve using the captured parameter. Item 2. The fluid temperature control device according to Item 1. 5. An auto-newning means for automatically detecting the personality of the equipped flow control valve, and providing the detected personality as the parameter to the flow control valve compensating means. The fluid temperature control device according to claim 4, further comprising: 6. A heat exchange between the first and second fluids in the heat exchanger by controlling a flow rate of at least one of the first fluid and the second fluid flowing through the heat exchanger by a flow control valve. Calculating a manipulated variable of the heat exchange capacity, wherein the manipulated variable of the heat exchange capacity and the flow rate so as to compensate for a nonlinearity of a cooling characteristic of the heat exchanger. With reference to a heat exchanger compensation table that defines the relationship between the flow rate of the control valve and the manipulated variable, determining the manipulated variable of the flow rate corresponding to the calculated manipulated variable of the heat exchange capacity; and In order to compensate for the non-linearity of the flow characteristic of the control valve, with reference to a flow control valve compensation table that defines the relationship between the operation amount of the flow rate and the operation amount of the position of the flow control valve, the determined flow rate is determined. Before corresponding to the manipulated variable of flow rate A fluid temperature control method, comprising: determining an operation amount of a position of the flow control valve; and operating the flow control valve using the determined operation amount of the position. 7. The flow control valve compensation table according to claim 6, wherein the flow control valve compensation table is based on a common flow characteristic that does not depend on individual differences of the flow control valves.
It defines the relationship between the manipulated variable of the flow rate and the manipulated variable of the position, and applies the personality of the equipped flow control valve as a parameter to the flow control valve compensation table to obtain the flow control valve compensation. 7. The fluid temperature control method according to claim 6, further comprising the step of adjusting the definition of the table so as to match the personality of the equipped flow control valve. 8. A heat exchanger for cooling the working fluid with the coolant, through which the working fluid and the coolant flow, a flow control valve for controlling a flow rate of the working fluid or the coolant flowing through the heat exchanger. An electric heater that heats the working fluid that has exited the heat exchanger; and a heater control unit that operates an output power of the heater to control the temperature of the working fluid that has exited the heater to a target temperature. A valve control unit that operates the flow control valve to control the cooling capacity of the heat exchanger, wherein the valve control unit performs a transient operation before the current temperature of the working fluid reaches the target temperature. Sometimes, during transient valve control means operating the flow rate control valve according to the rate of change of the current temperature, at the time of settling after the current temperature reaches the target temperature,
A fluid temperature control device comprising: a valve control means for setting the flow rate control valve so that the output power of the heater falls within a predetermined appropriate output range. 9. The stabilization-time valve control means, comprising: means for feeding back reference output power from the heater control unit; and when the reference output power is outside the proper output range.
Means for operating the flow control valve according to the magnitude of the deviation between the reference output power and the appropriate output range,
The fluid temperature control device according to claim 8. 10. The settling time valve control means calculates an operation amount of the flow control valve using a relatively large control gain during an overshoot immediately after the current temperature reaches the target temperature. 9. The fluid temperature control device according to claim 8, further comprising: means for calculating an operation amount of the flow control valve using a control gain of a relatively small value after the overshoot is over. 11. The settling time valve control means, means for detecting occurrence of hunting in which the output power of the heater oscillates in a width exceeding the proper output range, and when the hunting is detected, the flow rate control The fluid temperature control device according to claim 8, further comprising: means for reducing a control gain used for calculating an operation amount of the valve. 12. An operation amount of an output power of the heater by a speed-type I-PD control method using a relatively large control gain during the transient and the overshoot at the settling time. And a means for calculating the manipulated variable of the output power of the heater by a method of PID control using a relatively small control gain after the overshoot at the time of the settling is over. The fluid temperature control device according to any one of the preceding claims. 13. The working fluid, wherein a flow rate of a working fluid or a cooling fluid flowing through the heat exchanger is controlled by a flow control valve, and the working fluid exiting the heat exchanger is heated by an electric heater. A method for controlling the temperature of the working fluid exiting the heater to a target temperature, a heater control step of operating an output power of the heater, and controlling a cooling capacity of the heat exchanger. Further comprising a valve control step of operating the flow control valve, wherein the valve control step comprises: in a transient state before the current temperature of the working fluid reaches the target temperature, according to a change speed of the current temperature. A transient valve control step of operating the flow control valve, and at the time of settling after the current temperature has reached the target temperature,
A setting valve control step of operating the flow control valve so that the output power of the heater falls within a predetermined appropriate output range. 14. A valve control device for controlling a position of the flow control valve in order to control a flow flowing through the flow control valve, comprising: means for determining an operation amount of the flow control valve; and a flow characteristic of the flow control valve. The flow rate control valve compensating means that defines the relationship between the operation amount of the flow rate and the operation amount of the position of the flow control valve, so as to compensate for the nonlinearity of Means for determining the amount of operation of the position corresponding to the amount of operation of the flow rate, wherein the flow rate control valve compensation means operates the flow rate based on a common flow rate characteristic that does not depend on individual differences of the flow rate control valves. It has a definition of the relationship between the quantity and the manipulated variable of the position, captures the individuality of the flow control valve to be controlled as a parameter, and adapts to the personality of the equipped flow control valve using the captured parameter. I will do it The so as to adjust the definition, the valve control device.