JP2007193527A - Heater drive control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heater drive control method by which adjustment work for uniform temperature control can be completed with a comparatively less man-hour, and additional adjustment for uniform temperature control is not necessary even if the uniform temperature control is achieved at a temperature, then the control is switched to the uniform temperature control at a different temperature. <P>SOLUTION: The method comprises a first step for creating a rough table for creating an operation output value, a second step for creating a fine table for creating an operation output value, and a third step for extracting data corresponding to the operation output value of the servo system for each region corresponding to a reference temperature by searching the fine table for creating an operation output value with the specified reference temperature as a key every time a reference temperature is specified, and providing each operation output value created based on the data to the driving system in the corresponding region. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention provides a certain temperature distribution tendency (for example, for example, by providing an appropriate operation output to the drive system of each heater that individually heats each of a plurality of regions that are appropriately partitioned on the object to be heated. The present invention relates to a heater drive control method for causing a temperature distribution pattern having an entire surface uniform temperature, a gradient distribution temperature, a concentric distribution temperature, etc. to appear on an object to be heated.

  By providing an appropriate operation output to the drive system of each heater that individually heats each of the plurality of regions that are appropriately partitioned on the object to be heated, a constant temperature distribution tendency (for example, uniform temperature over the entire surface, etc.) A control system that causes a temperature distribution pattern having () to appear on an object to be heated is often employed in a heating process of a liquid crystal glass or a semiconductor wafer.

  An example of an image diagram of this type of uniform temperature control system (N: N control) is shown in FIG. In the figure, reference numerals 5-1 to 5-7 are deviation amplifiers, 6-1 to 6-7 are PID arithmetic units, 7-1 to 7-7 are drive systems including a drive circuit, a variable regulator, and the like. Control objects including seven heaters, 9-1 to 9-7 are temperature sensors. Here, “uniform temperature control” means control for eliminating temperature variations at a plurality of detection points arranged on a sheet-like or rod-like workpiece.

  In the case of N: N control, a servo system including a deviation amplifier 5, a PID calculator 6, an adjusting means 7, and a temperature sensor 9 is prepared for each of the seven heaters included in the control target 8. That is, each of the deviation amplifiers 5-1 to 5-7 includes a first detection value (PV1) to a seventh detection value (PV7) obtained from each of the temperature sensors 9-1 to 9-7 and a first set value ( The deviation from SP1) to the seventh set value (SP7) is amplified. Each output of the deviation amplifiers 5-1 to 5-7 is subjected to PID calculation by the first PID calculator 6-1 to the seventh calculator 6-7, and operation outputs (MV1 to MV7) are generated. . The drive systems 7-1 to 7-7 include seven (not shown) constituting the control target 8 based on the operation outputs (MV1 to MV7) of the first PID calculator 6-1 to the seventh calculator 6-7. Each of the heaters is driven. The temperatures of the regions corresponding to the seven heaters are detected by temperature sensors 9-1 to 9-7 provided in those regions, and the detected values (PV1 to PV7) are detected as deviation amplifiers 5-1 to 5-1. Sent to 5-7. Thus, a servo system is configured in which one output control is paired for one input.

  An example of an image diagram of another uniform temperature control system (M: N control) is shown in FIG. In the figure, 5,5-1 and 5-2 are deviation amplifiers, 6,6-1 and 6-2 are PID calculators, and 7-1 to 7-7 are drive circuits including a drive circuit and a variable regulator. The system, 8 is a control object including seven heaters, and 9, 9-1 and 9-2 are temperature sensors.

  As M: N control, in this example, there are shown a case where there is one PID computing unit (FIG. 1A) and a case where there are a plurality of PID computing units (FIG. 2B). That is, in the case shown in FIG. 5A, the deviation amplifier 5 amplifies the deviation between the detection value (PV) of the temperature sensor 9 and the set value (SP). The output of the deviation amplifier 5 is subjected to PID calculation by a PID calculator 6 to generate an operation output (MV). The drive systems 7-1 to 7-7 drive each of seven heaters (not shown) constituting the control object 8 based on the operation output (MV) of the PID computing unit 6. The temperature of the region corresponding to each of the seven heaters is detected by one temperature sensor 9 provided in the representative region of those regions, and the detected value (PV) is sent to the deviation amplifier 5. This constitutes a servo system in which seven output controls are paired for one input.

  On the other hand, in the case shown in FIG. 5B, the deviation amplifier 5-1 amplifies the deviation between the detected value (PV1) of the temperature sensor 9-1 and the set value (SP1). The output of the deviation amplifier 5-1 is subjected to PID calculation by the PID calculator 6-1 to generate an operation output (MV1). The drive systems 7-1 to 7-3 drive each of three heaters (not shown) constituting the control target 8 based on the operation output (MV1) of the PID calculator 6-1. Each of the three heaters is driven. The temperature of the region corresponding to each of the three heaters is detected by one temperature sensor 9-1 provided in the representative region of these regions, and the detected value (PV1) is sent to the deviation amplifier 5. It is done. Similarly, the deviation amplifier 5-2 amplifies the deviation between the detected value (PV2) of the temperature sensor 9-2 and the set value (SP2). The output of the deviation amplifier 5-2 is subjected to PID calculation by the PID calculator 6-2 to generate an operation output (MV2). The drive systems 7-4 to 7-7 drive each of four heaters (not shown) constituting the control object 8 based on the output (MV2) of the PID calculator 6-2. The temperature of the region corresponding to each of the four heaters is detected by one temperature sensor 9-2 provided in the representative region of those regions, and the detected value (PV2) is the deviation amplifier 5-2. Sent to. Thus, a servo system is configured in which seven output controls are paired for two inputs.

  By the way, the uniform temperature control system shown in FIGS. 15 and 16 has one or more servo systems for temperature control, but it is particularly adjacent among the partitioned areas on the object to be heated. Since there is a thermal interference between the areas, it is difficult to immediately produce a uniform temperature distribution on the object to be heated simply by setting the same target value for each servo system. Therefore, manual adjustment work is absolutely necessary.

  In the case of FIGS. 15 and 16, this adjustment work is performed by a variable regulator (variable resistor or the like) incorporated in a drive circuit (solid state relay or power regulator) included in the drive systems 7-1 to 7-7. (Which is composed of hardware), and a method of adding / subtracting appropriate numerical values in software to the operation output of the PID computing units 7-1 to 7-7 located in the preceding stage is adopted. Is done.

  Attempts have also been made to automate this adjustment work. In other words, the applicant first has interference between adjacent regions, and therefore, temperature variation is particularly noticeable during transients and disturbances, and uniform temperature control is difficult. In order to solve the problem that it is difficult to control to different target temperatures, one of thermal interference compensation control techniques between regions (hereinafter referred to as “gradient temperature control”) is proposed. Yes.

This gradient temperature control is a means for converting detected temperatures obtained from a plurality of temperature detection means that respectively detect temperatures to be controlled into gradient temperatures based on a plurality of detected temperatures, and also converting them into representative representative temperatures; Each temperature control unit outputs a plurality of temperature control units that output an operation signal using the gradient temperature or representative temperature from the conversion unit as a controlled variable, and a plurality of heating units that heat the control target with the operation signal from each temperature control unit. Distribution means for allocating the control by means so as to eliminate or reduce the influence on the control by other temperature control means (see, for example, Patent Document 1).
JP 2000-187514 A

  However, in the conventional heater drive control method for uniform temperature control, the following problems have been pointed out when performing a plurality of output controls.

  First, there is a problem that it takes an enormous amount of time for the condition setting operation to achieve a uniform temperature when the apparatus is shipped. That is, due to thermal interference between heaters, adjustment of one heater temperature affects the temperature of adjacent heaters, so it may be necessary to return to the adjusted heater and adjust the temperature again. If there are many, the adjustment man-hours will be enormous. Moreover, even if uniform temperature control is achieved at a certain temperature, each time the temperature at which uniform temperature control is to be performed is changed, an enormous number of work steps are required as in the initial adjustment.

  Second, there is a problem that adjustment is mostly based on intuition and experience, and that it is difficult to pass on technology. That is, a skilled worker can reduce the number of readjustments to some extent by predicting the influence of thermal interference with adjacent heaters based on experience and intuition, and adjusting the temperature to some extent. Because the degree is different, it is difficult to transfer to other people through technical training.

  Thirdly, there is a problem that it takes time and effort especially when performing M: N control. That is, depending on the user, M: N control is often performed, but in general, when the apparatus is in normal operation, the number of sensors may be reduced for the purpose of down or space reduction when compared with the time of shipment of the apparatus. Many. At this time, since the number of sensors is different between the time of adjustment and the time of operation, it may take time for adjustment again.

  Fourth, in the case of performing M: N control, parameters for obtaining a uniform temperature condition are increased as compared with N: N control, and the difficulty of adjustment is further increased. There is a problem that the adjustment is based on the experience and intuition of engineers, and it takes a lot of work time. In other words, the influence of thermal interference between the heaters is significant, and in order to make the temperature of the workpiece uniform, it is necessary to balance the output of multiple heaters. I need.

  The present invention has been made paying attention to the above-mentioned problems, and the object of the present invention is to complete the adjustment work for uniform temperature control with a relatively small number of work steps, and at a certain temperature. Even after switching to uniform temperature control at a different temperature after achieving uniform temperature control at, no adjustment work for uniform temperature control is required, and N: N control is used for uniform temperature control. An object of the present invention is to provide a heater drive control method capable of continuing operation without any trouble even after switching to uniform temperature control by M: N control after adjustment.

  Other objects and operational effects of the present invention should be easily understood by those skilled in the art by referring to the following description of the specification.

  The heater drive control method of the present invention provides a constant temperature by giving an appropriate operation output to the drive system of each heater that individually heats each of a plurality of regions that are appropriately partitioned on the object to be heated. This is for causing a temperature distribution pattern including an arbitrary reference temperature having a distribution tendency and selectable at a predetermined resolution to appear on the object to be heated.

  This heater drive control method includes three steps including a first step, a second step, and a third step.

  In the first step, a predetermined correction operation is performed by inputting a deviation between a detected value from a temperature sensor provided for each region and a target value for each region, and an operation output for each region is performed. A target temperature distribution in which an actual temperature distribution pattern as a whole group of areas is associated in advance with one reference temperature while applying thermal interference compensation control between the areas to the servo system for each area that generates The process of matching the pattern is repeated by changing the reference temperature at intervals sufficiently larger than the reference temperature resolution, and every time the actual temperature distribution pattern matches the target temperature distribution pattern, the process for matching each pattern is performed. The data corresponding to the servo system operation output value is acquired and stored in a predetermined memory in association with the reference temperature at that time. To generate Le.

  The second step corresponds to at least the reference temperature resolution between the data corresponding to the operation output values of the servo system for each region stored in the predetermined memory in association with the reference temperature based on the temperature distribution tendency. A fine table for generating an operation output value is generated by interpolating at a predetermined interval and storing the result in a predetermined memory.

  In the third step, every time a reference temperature is designated, a fine table for generating an operation output value is searched using the designated reference temperature as a key, so that the servo system for each region corresponding to the reference temperature is searched. Data corresponding to the operation output value is extracted, and each operation output value generated based on this data is given to the drive system in the corresponding region.

  Here, the “constant temperature distribution tendency” includes a uniform temperature distribution pattern in which the temperature in all regions is uniform, and besides that, the temperature gradually increases along a certain direction. Various temperature distribution patterns are included, such as an inclined temperature distribution pattern in which the temperature increases or decreases, or a temperature distribution pattern in which the temperature gradually increases or decreases in the radial direction on a concentric circle.

  The “data corresponding to the servo system operation output value for each area” includes the servo system operation output value of one area defined as the representative area, the operation output value of the representative area, and other areas. In addition to the correlation data with the respective operation output values, not only the representative area but also other areas may include individual operation output values instead of the correlation data. Here, for “correlation data”, a ratio (for example, percentage), a deviation, and the like can be widely used.

  According to the present invention, adjustment work for uniform temperature control can be completed with a relatively small number of work steps, and after achieving uniform temperature control at a certain temperature, uniform temperature control at another temperature can be achieved. Even if it is switched, adjustment work for uniform temperature control is no longer necessary, and after adjusting uniform temperature control by N: N control, switching to uniform temperature control by M: N control An object of the present invention is to provide a heater drive control method capable of continuing operation without any trouble.

  Hereinafter, a preferred embodiment of a heater drive control method according to the present invention will be described in detail with reference to the accompanying drawings.

  As described above, the heater drive control method of the present invention provides an appropriate operation output to the drive system of each heater that individually heats each of a plurality of regions that are appropriately partitioned on the object to be heated. By applying, a temperature distribution pattern including an arbitrary reference temperature that has a constant temperature distribution tendency and is selectable with a predetermined resolution appears on the object to be heated.

  In this method, a first step for generating a coarse table for generating operation output, a second step for generating a fine table for generating operation output, and each operation output value in a corresponding region And a third step for giving to the drive system.

  In the first step, a predetermined correction calculation is performed by inputting a deviation between a detected value from a temperature sensor provided for each region and a target value for each region, and an operation output for each region is performed. A target temperature distribution in which an actual temperature distribution pattern as a whole group of areas is associated in advance with one reference temperature while applying thermal interference compensation control between the areas to the servo system for each area that generates The process of matching the pattern is repeated by changing the reference temperature at intervals sufficiently larger than the reference temperature resolution, and every time the actual temperature distribution pattern matches the target temperature distribution pattern, the process for matching each pattern is performed. The data corresponding to the servo system operation output value is acquired and stored in a predetermined memory in association with the reference temperature at that time, so that the rough output for generating the operation output value is obtained. Operation of generating a table is executed.

  In the subsequent second step, between the data corresponding to the operation output values of the servo system for each region stored in association with the reference temperature in a predetermined memory, at least the reference temperature resolution is based on the temperature distribution tendency. An operation for generating a fine table for generating an operation output value is executed by interpolating at a corresponding interval and storing the result in a predetermined memory.

  In the subsequent third step, every time the reference temperature is designated, the fine system table for generating the operation output value is searched by using the designated reference temperature as a key, whereby the servo system for each area corresponding to the reference temperature is searched. The operation corresponding to the operation output value is extracted and the operation output value generated based on this data is applied to the drive system in the corresponding region.

  Of the above steps, in order to execute the operation in the first step, the servo control function (preferably N: N control) described above with reference to FIGS. A function of compensating for thermal interference between regions such as “gradient temperature control” previously proposed in Japanese Patent Laid-Open No. 2000-187514 is required. The gradient temperature control is described in detail in the same publication, but in short, the detected temperatures obtained from the plurality of temperature detecting means for detecting the temperatures of the controlled objects are converted into the gradient temperatures based on the plurality of detected temperatures. A means for converting to a representative representative temperature, a plurality of temperature control means for outputting an operation signal using the gradient temperature or representative temperature from the conversion means as a controlled variable, and an operation signal from each temperature control means. The distribution means for allocating the plurality of heating means for heating the controlled object so as to eliminate or reduce the influence of the control by each temperature control means on the control by the other temperature control means.

  Further, in order to execute the operation in the second step, an interpolation operation function for performing interpolation between numerical data strings is required.

  Furthermore, in order to execute the operation in the third step, a table search function for searching for and outputting an operation output value for each of a plurality of regions using a given target temperature as an argument is required.

  All of these functions (servo control function, thermal interference compensation function, interpolation / interpolation calculation function, table search function, etc.) can be performed on a general-purpose personal computer, etc., and are therefore necessary for executing each step of the method of the present invention. By incorporating such functions into a personal computer, the method of the present invention can be embodied as a heater drive control device using a personal computer as an implementation means.

  On the other hand, with regard to the servo control function, a temperature controller sold under a trade name such as a PID temperature controller, a programmable controller (hereinafter referred to as “PLC”) having a function block for PID calculation, etc. Since it is incorporated, the functions of the present invention are implemented as a temperature controller or PLC having such a heater drive control function by incorporating the functions necessary for executing the steps of the method of the present invention into those devices. You can also

  When a personal computer, a temperature controller, a PLC and the like including functions for executing the steps of the present invention are generalized as a “control device”, the system configuration of the temperature control system to which the present invention is applied is the control device and the drive system. And a heater and a sensor.

  Accordingly, the heater drive control method of the present invention is premised on a temperature control system (particularly, in this example, a uniform temperature control system) having a system configuration including a control device, a drive system, a heater, and a sensor. Will be described in detail.

  In addition, the control apparatus used for this heater drive control method is prepared with two operation modes consisting of a calibration mode and a normal mode (see FIG. 3). The first and second steps of the present invention are performed in the calibration mode, while the third step of the present invention is performed in the normal mode. It should be noted that the switching of processing corresponding to these operation modes is automatically executed (step 302 or 303) in response to an on / off operation of a predetermined flag by the user (step 301).

  An explanatory diagram showing the system configuration of the control system in the calibration mode is shown in FIG. As shown in the figure, the uniform temperature control system includes a control device 1, a drive system 2, a heater plate 3, and nine sensors S1 to S9.

  The control device 1 includes nine deviation calculators and PID calculators corresponding to the deviation amplifiers 5-1 to 5-7 and the PID calculators 6-1 to 6-7 described above with reference to FIG. Built-in functionality. In addition, this control device also incorporates a function for executing the first to third steps of the present invention. These functions will be described later in detail with reference to the flowcharts of FIGS.

  In this example, the drive system 2 includes nine independent drive system elements (2-1 to 2-9). The specific hardware configuration of the drive system elements (2-1 to 2-9) is determined by the signal form of nine operation outputs (MV1 to MV9) output from the control device 1. That is, when the signal form of the operation outputs (MV1 to MV9) is an analog quantity, a power regulator capable of continuously adjusting power is employed as the element drive system. On the other hand, when the signal form of the operation output is a pulse train such as a PWM signal, a solid state relay (SSR) capable of chopper control is adopted as the element drive system. The signal line 4a includes nine operation outputs (MV1 to MV9).

  In this example, the heater plate 3 is divided into nine regions of 3 rows in the vertical direction and 3 columns in the horizontal direction, and each region has a heater H1 that individually heats each region. To H9. Then, each of these nine heaters H1 to H9 is driven by each output of nine drive system elements (2-1 to 2-9) included in the drive system 2.

  In each of the nine divided areas of the heater plate 3, temperature sensors S1 to S9 for detecting the temperature of each area are detachably provided. Outputs of these temperature sensors S1 to S9 are sent as detection values (PV1 to PV9) to each of nine deviation amplifiers in the control device 1, and each deviation amplifier has a predetermined target value (SP1 to SP9). To be compared. Each deviation output of the nine deviation amplifiers is given to nine PID calculators arranged in the subsequent stage, and new operation outputs are generated from these PID calculators. The signal line 4b includes sensor output signals corresponding to nine systems of temperature detection values.

  Next, a flowchart showing details of the calibration mode process is shown in FIG. The process shown in this flowchart is executed by the control device 1 included in the system configuration of FIG.

  When the process is started in the figure, as a pre-process for generating a rough table for generating an operation output, a plurality of measurement point temperatures at which a profile is to be created are stored in advance in the memory of the controller (meaning the control device 1) in T1. , T2... Tm,... Tn are stored (step 401). Here, the “profile” refers to a group of operation outputs (MV1 to MV9) in a state where the temperatures of the nine regions corresponding to the heaters H1 to H9 are made uniform at a certain measurement point temperature, and corresponding data. Is stored in the memory of the controller.

  At this time, Tn−T1 is determined in consideration of the upper and lower limits of the temperature range to be uniformly controlled. Further, the measurement point temperature intervals T2-T1, T3-T2, T4-T3,... For which a profile is to be created can be determined to an arbitrary value sufficiently larger than the target temperature resolution.

  FIG. 5 is an explanatory diagram showing an example of measurement points (points) in the calibration mode. As shown in the figure, in this example, the lower limit of the control range is 0 ° C., the upper limit is 1000 ° C., and the measurement point temperature interval is 50 ° C.

  Returning to FIG. 4, when the preprocessing is completed, a series of processing corresponding to the first step of the present invention is executed (steps 402 to 405). That is, first, the measurement point temperature Tm (= T1) is set as the set value (SP1 to SP9) for each of the nine deviation amplifiers (see reference numerals 5-1 to 5-7 in FIG. 15) constituting the servo control system. On the other hand, by applying a thermal interference compensation technique between regions to a series of nine servo control systems, the temperature of each region is reduced to the measurement point temperature Tm (= T1) by PID control. A process of raising and setting is executed (step 402).

  At this time, as a technique for compensating for thermal interference between regions, “gradient temperature control” previously proposed by the present applicant in Japanese Patent Laid-Open No. 2000-187514 can be used. The gradient temperature control is described in detail in the same publication, but in short, the detected temperatures obtained from the plurality of temperature detecting means for detecting the temperatures of the controlled objects are converted into the gradient temperatures based on the plurality of detected temperatures. A means for converting to a representative representative temperature, a plurality of temperature control means for outputting an operation signal using the gradient temperature or representative temperature from the conversion means as a controlled variable, and an operation signal from each temperature control means. The distribution means for allocating the plurality of heating means for heating the controlled object so as to eliminate or reduce the influence of the control by each temperature control means on the control by the other temperature control means.

  If the temperature of the nine regions rises to the measurement point temperature Tm (= T1) and is set, then nine systems (9CH) corresponding to each region (9CH) PID computing units (reference numeral 15- in FIG. 15). The operation output (MV1 to MV9) of 1 to 15-7) is acquired and stored in the memory, thereby generating a profile at the measurement point temperature (step 403).

  In this way, if a profile for the measurement point temperature Tm (= T1) is generated, it is subsequently determined whether or not the measurement point temperature Tm at that time has reached the upper limit temperature Tn (step). 404) If the upper limit temperature has not yet been reached (NO in step 404), the measurement point temperature Tm is changed to the next measurement point temperature (step 405), and the above processing (steps 402 and 403) is repeatedly executed. Then, the profile for each measured temperature is stored in the memory as T1 (MV1 to MV9), T2 (MV1 to MV9), T3 (MV1 to MV9), etc. (as shown in FIG. 5). Temperature graph).

  An explanatory diagram showing the relationship between the operation output value (MV value) and the memory storage address is shown in FIG. As shown in the figure, the operation output values (MV1 to MV9) of the respective channels (CH1 to CH9) at the measurement point temperature T1 are stored in the memory addresses 0001 to 0009. Similarly, the operation output values (MV1 to MV9) of the respective channels (CH1 to CH9) at the measurement point temperature T2 are stored in the memory addresses 0010 to 0018.

  If the measurement point temperature Tm coincides with the upper limit temperature Tn while generating the profile while increasing the measurement point temperature Tm stepwise (step 404 YES), each measurement point temperature (T1 to T1) is stored in a predetermined area in the memory. For every Tn), nine channel operation output values (MV1 to MV9) are stored.

  In this way, if nine channel operation output values (MV1 to MV9) are stored for each measurement point temperature (T1 to Tn), then the operation output values are normalized by normalizing these operation output values. A coarse table for generating the operation output of the invention is generated (step 406). This normalization processing is performed on the other channels (1CH to 4CH, 6CH to 9CH) with the operation output value (MV5) of the central channel (5CH in this example) as a reference (100%) in the normal mode described later. This is done by determining the percentage of the output value. The operation output value (MV5) of the central channel thus obtained and the percentage of the operation output values of the other channels (1CH to 4CH, 6CH to 9CH) are stored in the memory in relation to each other. A rough table for output generation is generated.

  A rough table for generating the operation output generated in this way is shown in FIG. As shown in the figure, the rough table for generating operation output includes operation output values (9 to CH9) for each of a plurality of measurement point temperatures set at 50 ° C. intervals (CH1 to CH9). MV1 to MV9) are stored as percentage values with respect to the operation output value (MV5) of the central 5CH. That is, the percentage value of each channel obtained in this way becomes data corresponding to the operation output values (MV1 to MV9) of each channel.

  When the rough table for generating the operation output is generated in this way, the interpolation process corresponding to the second step of the present invention is subsequently executed (step 407). In this interpolation process (step 407), as shown in the graph of FIG. 8, a known interpolation technique is used between nine operation output values (MV1 to MV9) between adjacent measurement point temperatures. Then, by connecting with a gentle curve, nine operation output values (MV1 to MV9) for each measurement point temperature obtained by dividing the adjacent temperature interval 50 ° C. with a predetermined resolution are obtained by calculation, and a predetermined area of the memory To store the fine table for generating the operation output, which is a profile corresponding to the entire temperature range (step 408).

  In the graph of FIG. 8, the points where dots (◯, triangles, squares, x, etc.) are displayed are the measured values of the operation output, and the lines connecting these dots are the interpolated calculation values. . Examples of the resolution for further engraving the 50 ° C. interval include 1 ° C. unit, 5 ° C. unit, 10 ° C. unit, and the like. In the figure, a is the operation output of CH1, b is the operation output of CH2, c is the operation output of CH3, d is the operation output of CH4, e is the operation output of CH5, f is the operation output of CH6, and g is CH7. , H is the operation output of CH8, and i is the operation output of CH9.

  Next, the normal mode process in the control device 2 will be described in detail. An explanatory diagram showing the system configuration of the control system in the normal mode is shown in FIG. As shown in the figure, in the normal mode, except for one sensor S9, the other eight sensors S1 to S8 are removed from the system. This is because a temperature sensor is provided in each area because of the necessity of feedback control in the calibration mode, but since no feedback control is performed in the normal mode, basically there is no temperature sensor from the viewpoint of temperature control. It is unnecessary. Therefore, the control system according to the present invention does not require a temperature sensor except for the purpose of temperature display at the stage of delivery to the customer, and the cost can be reduced accordingly.

  A flowchart showing details of the normal mode processing is shown in FIG. In this normal mode process, the process of the third step of the present invention is executed. In the figure, when the process is started, first, a setting value (SP) is set in conjunction with a user setting operation (step 901). Here, the set value (SP) means a setting at what degree of temperature to make the nine regions on the heated object uniform temperature. In this specific example, in the temperature range of 0 ° C. to 1000 ° C., it is set at what temperature the nine regions on the object to be heated are made uniform.

  If the setting of the set temperature value (SP) is completed in this way (step 901), then the set temperature value (SP) is obtained from the profile data (fine table for generating output values) obtained in the calibration mode. ) Of the operation output values (MV1 to MV9) of each channel (CH1 to CH9) is read (step 902). In other words, by searching the fine table (see the graph of FIG. 8) for generating an operation output value using the designated reference temperature (set temperature value (SP)) as a key, each region ( Data (ratio (%)) corresponding to the operation output values (MV1 to MV9) of the servo system for each of CH1 to CH9) is extracted.

  In this way, if data (ratio (%)) corresponding to the servo system operation output values (MV1 to MV9) for each region (CH1 to CH9) corresponding to the set temperature (SP) is extracted, Subsequently, by multiplying the operation output value (MV5) of the reference point (5CH in this example) as the center of control by the operation output value (MV1 to MV9) of each channel (CH1 to CH9), The operation output values (MV1 to MV9) of the channel are reproduced, and a process of outputting these operation output values (MV1 to MV9) to the drive system elements of each system is executed (step 903).

  Then, the drive system elements of each system are given the same values as the respective operation output values in the state where the respective areas are made uniform at the set temperature (SP), and therefore the areas corresponding to the respective heaters H1 to H. This temperature is made uniform at the set temperature (SP) by itself without relying on a feedback system. Thereafter, when it is desired to change the temperature to be uniform while maintaining the temperature uniformity, the temperature after the change may be given to the control device 1 as the set temperature (SP). Then, by performing the same processing (steps 901 to 903) as in the previous case, the temperature of the area corresponding to each of the heaters H1 to H is made uniform at the new set temperature (SP) alone. It is.

  Next, another embodiment of the heater drive control method according to the present invention will be described in detail with reference to FIGS. In this embodiment, not only in the settling state, but also in the period up to the settling time, temperature uniformity between the channels is guaranteed.

  Also in this embodiment, the hardware system configuration is the same as that shown in FIGS. 1 and 2, and also includes calibration mode processing and normal mode processing as shown in FIG. Yes.

  Also for the period up to the settling time, a flowchart of the calibration process in the case of achieving temperature uniformity between the respective channels is shown in FIG. Then, a process of determining a temperature value (PV value) that shifts from transient to settling is performed in conjunction with a user operation (step 1001). In this example, the temperature value (PV value) that transitions from rising to transition is determined to be T1 ° C., and the temperature value (PV value) that transitions from transient to settling is determined to be T2 ° C.

  After setting a desired temperature increase temperature (160 ° C. in this example) as a target value (SP) of the servo system (step 1002), PID calculation control by N: N control is executed to perform the temperature increase operation. , A process (step 1003) for acquiring operation outputs (MV1 to MV5) of each channel (CH1 to CH5 in this example) in a time series with a predetermined resolution, the current temperature (PV) is a servo system target value (SP ) Is repeated (NO in step 1004).

  During this time, if the current temperature (PV) reaches the target value (SP) of the servo system (step 1004 YES), each channel acquired from the start of control until the temperature T1 is exceeded ("rise period") An average value of the operation outputs (MV1 to MV5) of (CH1 to CH5) is obtained by calculation, and processing for storing the result in a predetermined memory is executed (step 1005). As a result, a group of operation output values (MV1 to MV5) required to equalize the temperature values (PV1 to PV5) of the respective channels at the time of start-up are obtained, and a rough table for generating operation outputs at the time of start-up is obtained. Complete.

  In this way, when the rough table for generating the operation output for equalizing the temperature at the start-up is completed, the channel (CH) having the largest operation amount is subsequently selected from the rough table. The average operation amount (MVmax) and the ratio (percentage) between the operation amount (MVmax) and the operation amount (MV1 to MV5) of each channel are obtained and stored in a predetermined area of the memory, so that the temperature is uniform at startup. A fine table for generating an operation output for conversion is completed (step 1006).

  Thereafter, the operation output (MV1 to MV5) of each channel (CH1 to CH5 in this example) is time-sequentially with a predetermined resolution while performing the temperature raising operation by executing the PID calculation control by N: N control. The acquisition process (step 1007) is repeatedly executed until the current temperature (PV) reaches the servo system target value (SP) (NO in step 1008).

  During this time, if the current temperature (PV) has reached the target value (SP) of the servo system (step 1008 YES), each channel acquired from the start of control until the time when the temperature T1 is exceeded (“transient period”) ( An average value of the operation outputs (MV1 to MV5) of CH1 to CH5) is obtained by calculation, and a process of storing the result in a predetermined memory is executed (step 1009). As a result, a group of operation output values (MV1 to MV5) required to equalize the temperature values (PV1 to PV5) of the respective channels during the transition are obtained, and a rough table for generating the operation output during the transition is completed. .

  In this way, when the rough table for generating the operation output for equalizing the temperature during the transition is completed, the average of the channels (CH) having the largest operation amount is subsequently selected from the rough table. By calculating the operation amount (MVmax) and the ratio (percentage) between the operation amount (MVmax) and the operation amount (MV1 to MV5) of each channel and storing it in a predetermined area of the memory, it is possible to equalize the temperature during the transition. A fine table for generating a manipulation operation output is completed (step 1010).

  The contents of the rough table for generating the operation output for equalizing the temperature at the time of “rise” and “transient” generated in this way are shown in the graph of FIG. As shown in the figure, the period to reach the settling state is divided into two phases consisting of “rise time” and “transition time”.

  In this example, the average manipulated value of each channel (CH1 to CH5) at the time of “rise” is 3,5CH average manipulated variable> 1CH average manipulated variable> 4CH average manipulated variable> 2CH average manipulated variable. The magnitude relationship is established. In this case, the average manipulated variable (MVmax) of the channel (3CH or 5CH) having the largest manipulated variable from the rough table and the ratio of the manipulated variable (MVmax) to the manipulated variable (MV1 to MV5) of each channel ( The percentage table is obtained and stored in a predetermined area of the memory, thereby completing a fine table for generating an operation output for equalizing the temperature at the time of start-up.

  In this example, the average manipulated value of each channel (CH1 to CH5) at the time of “transition” is as follows: 3CH average manipulated variable> 5CH average manipulated variable> 4CH average manipulated variable> 1CH average manipulated variable> 2CH The magnitude relation of the average operation amount is established. In this case, the average operation amount (MVmax) of the channel (3CH) having the largest operation amount in the rough table and the ratio (percentage) between the operation amount (MVmax) and the operation amounts (MV1 to MV5) of each channel. Is stored in a predetermined area of the memory, thereby completing a fine table for generating an operation output for equalizing the temperature during the transition.

  It should be noted that the period until reaching the settling state is determined based on the current value (PV value), the elapsed time, the operation amount (MV value), etc. What is necessary is just to employ | adopt the optimal carving method. In this example, the period leading to “settling time” is divided into two periods of “rising time” corresponding to the period from the start to the temperature T1 and “transient time” corresponding to the temperature T2. It is carved.

  Next, normal mode processing will be described. FIG. 12 is a flowchart showing normal mode processing in the case where temperature equalization is achieved even during a period until settling. In the figure, when the processing is started, first, the instruction temperature (SP) designated by the user is set as the set temperature of the five servo systems (including the deviation amplifier and the PID calculator) in conjunction with the user operation. A setting process is executed (step 1201). In this example, the “indicated temperature (SP)” is used to determine the temperature at which the temperature is uniformed for the five regions set on the object to be heated. is there.

  The memory of the control device 1 includes three types of operation outputs (MV1 to MV5) that are to be given to the drive systems of each system at the time of “rise”, “transition”, and “at the time of settling”. A table is stored in association with the indicated temperature (SP).

  When the setting of the indicated temperature (SP) is completed, the average manipulated value (MV value) of each channel (CH1 to CH5) stored in the memory in the calibration mode is then set to “when rising”. The processing (step 1202) of reading out from the fineness table and giving the average manipulated variable to the drive system of each channel determines the boundary between the detected temperature (PV) of the region “at the time of rising” and “at the time of transient”. The process is repeatedly executed until the specified temperature T1 is reached (NO in step 1203).

  During this time, when the detected temperature (PV) of the region reaches a temperature T1 that defines the boundary between “rising time” and “transient time” (step 1203 YES), subsequently, “transient” stored in the memory in the calibration mode. A process (step 1204) of reading the average manipulated variable (MV value) of each channel (CH1 to CH5) of “hour” from the fine table of “transient” and giving the average manipulated variable to the drive system of each channel (step 1204). The process is repeatedly executed until the detected temperature (PV) of the region reaches a temperature T2 that defines the boundary between “transient” and “settling” (NO in step 1205).

  During this time, when the detected temperature (PV) of the region reaches a temperature T2 that defines the boundary between “transient” and “settling” (YES in step 1205), subsequently, “settling time” stored in the memory in the calibration mode. The processing amount (MV value) of each of the channels (CH1 to CH5) is read from the fine table of “at the time of settling”, and the operation amount (step 1206) is given to the driving system of each channel. . As a result, as shown in FIG. 11, the temperature of the plurality of regions corresponding to each channel is maintained at a uniform temperature at any of “rising time”, “transient time”, and “setting time”. .

  Finally, a more specific system configuration for carrying out the method of the present invention will be described. As described above, the functions of the control device 1 in the system configuration of FIGS. 1 and 2 are the control personal computer with the PID calculation function, the PLD with the PID calculation function block, and the PID calculation function. This can be realized by incorporating processing corresponding to each step of the method of the present invention into the built-in temperature controller and the like.

  Therefore, as an example, FIG. 13 shows an example of the configuration of the uniform temperature control device to which the present invention is applied using a PLC. The PLC 1 a that functions as a control device includes a power supply unit 11, a CPU unit 12, an analog input unit 13, and an output unit 14.

  As shown in FIG. 14, the CPU unit 12 of the PLC 11a has a ROM 12a for storing a system program (firmware), a microprocessor 12b for controlling the entire CPU unit, and a user using a ladder diagram language and function blocks. A user program memory 12c for storing user programs created arbitrarily, a work RAM 12d used as a work area when the microprocessor 12b executes various calculations, and various data necessary for the calculations are stored. Data storage nonvolatile memory 12e, ASIC 12f having a function of reading and executing various user instructions from the user program memory 12c, and input / output for storing data corresponding to an input or output signal included in the external input / output unit Memo It is included and 12g.

  The user uses a ladder diagram language, a function block for PID calculation, and the like to create a user program that realizes a function corresponding to the servo control system shown in FIG. The user program created in this way is stored in the user program memory 12c. The user also realizes a user program corresponding to the functions shown in the flowcharts of FIGS. 3 to 5 by using a ladder diagram language, a function block for PID calculation, and the like. At this time, the coarse table for generating the operation output shown in FIGS. 6 to 8 and the fine table obtained by interpolating the coarse table are stored in the data storage nonvolatile memory 12e. Thus, when the PLC 1a is activated, as shown in FIG. 3, the calibration mode process (step 302) and the normal mode process (step 303) are executed, and the heater drive control according to the present invention is realized. The

  According to the present invention, adjustment work for uniform temperature control can be completed with a relatively small number of work steps, and after achieving uniform temperature control at a certain temperature, uniform temperature control at another temperature can be achieved. Even if it is switched, readjustment work for uniform temperature control is no longer necessary, and after adjusting uniform temperature control by N: N control, switching to uniform temperature control by M: N control is possible. It becomes possible to continue driving without any trouble.

It is explanatory drawing which shows the system configuration | structure of a control system at the time of a calibration mode. It is explanatory drawing which shows the system configuration | structure of the control system at the time of normal mode. It is a general flowchart which shows operation | movement of the uniform temperature control apparatus with which the method of this invention was applied. It is a flowchart which shows the detail of a calibration mode process. It is explanatory drawing which shows the example of a measurement point at the time of calibration mode. It is explanatory drawing which shows the relationship between an operation output value (MV value) and a memory storage address. It is explanatory drawing which shows the content of the rough table for operation output generation | occurrence | production as a table | surface. It is explanatory drawing which shows the content of the fine table for operation output generation | occurrence | production on a graph. It is a flowchart which shows the detail of a normal mode process. It is a flowchart which shows the calibration process in the case of achieving temperature equalization also about the period to the time of settling. It is explanatory drawing which shows the operation amount in the case of achieving temperature equalization also about the period to the time of settling. It is a flowchart which shows the normal mode process in the case of achieving temperature equalization also about the period to the time of settling. It is explanatory drawing which shows the structural example by PLC of the uniform temperature control apparatus with which this invention was applied. It is a block diagram which shows the hardware constitutions of CPU unit of PLC. It is an image figure of a uniform temperature control apparatus (N: N control). It is an image figure of a uniform temperature control apparatus (M: N control).

Explanation of symbols

1 Controller 1a PLC
2 Drive system 3 Heater plate 4a Signal line (including operation output signal)
4b Signal line (including temperature detection signal)
5,5-1 to 5-7 Deviation amplifier 6,6-1 to 6-7 PID computing unit 7-1 to 7-7 Drive system 8 Control target 9,9-1,9-2 Temperature sensor 11 Power supply unit 12 CPU unit 12a System ROM
12b Microprocessor (MPU)
12c User program memory (UM)
12d Work RAM
12e Non-volatile memory for data 12f ASDIC having instruction execution function
12g Input / output memory (IOM)
13 Analog input unit 14 Output unit a ch1 interpolation complement curve b ch2 interpolation complement curve c ch3 interpolation complement curve d ch4 interpolation complement curve e ch5 interpolation complement curve f ch6 interpolation complement curve g interpolation interpolation curve of ch7 h interpolation interpolation curve of ch8 i interpolation interpolation curve of ch9 H1 to H9 heater S1 to S9 temperature sensor

Claims (3)

By providing an appropriate operation output to the drive system of each heater that individually heats each of a plurality of regions that are appropriately partitioned on the object to be heated, the temperature has a constant temperature distribution and a predetermined resolution. A heater drive control method for causing a temperature distribution pattern including an arbitrary reference temperature selectable in (1) to appear on an object to be heated,
Each region that generates a manipulation output for each region by performing a predetermined correction calculation by inputting a deviation between a detection value from a temperature sensor provided for each region and a target value for each region. A process of matching the actual temperature distribution pattern of the entire group of regions with the target temperature distribution pattern previously associated with one reference temperature while applying thermal interference compensation control between the regions to the servo system of Each time the actual temperature distribution pattern matches the target temperature distribution pattern, the operation output value of the servo system in each alignment state is repeated each time the reference temperature is changed at intervals sufficiently larger than the reference temperature resolution. Is obtained in association with the reference temperature at that time and stored in a predetermined memory to generate a rough table for generating an operation output value. And the step,
Interpolation between data corresponding to the operation output value of the servo system for each region stored in association with the reference temperature in a predetermined memory based on the temperature distribution tendency and at least at intervals corresponding to the reference temperature resolution A second step of generating a fine table for generating an operation output value by storing in a predetermined memory;
Each time a reference temperature is specified, the operation output value generation fine table is searched by using the specified reference temperature as a key, thereby corresponding to the operation output value of the servo system for each region corresponding to the reference temperature. A third step of extracting data and providing each operation output value generated based on the data to the drive system in the corresponding region;
The heater drive control method characterized by comprising.   The heater drive control method according to claim 1, wherein the constant temperature distribution tendency is that the temperature of all regions is uniform.   The data corresponding to the servo system operation output value for each area includes the servo system operation output value of one area defined as the representative area, the operation output value of the representative area, and the operation output of each of the other areas. The heater drive control method according to claim 1, further comprising correlation data with values.

Images