JP2010218007A - Disturbance estimation device, control object model estimation device, feedforward amount estimation device, and controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To estimate a parameter of a disturbance waveform and a control object model without performing measurement for identifying the disturbance waveform or the control object model each time operation conditions are made different. <P>SOLUTION: The disturbance estimation device is configured to estimate the disturbance waveform at a set temperature 200&deg;C by interpolation from a disturbance waveform measured at a set temperature 100&deg;C and a disturbance waveform measured at a set temperature 300&deg;C, thereby eliminating the necessity of measuring the disturbance waveform at the set temperature 200&deg;C. Also, it is possible to estimate the feedforward correction amount at the set temperature 200&deg;C by using the interpolated disturbance waveform. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a disturbance estimation device for estimating a disturbance waveform applied to a control target, a control target model estimation device for estimating parameters of a control target model, and a feedforward correction amount that is a correction amount of an operation amount or a target value in feedforward control. The present invention relates to a feedforward amount estimation device for estimating (hereinafter also referred to as “FF correction amount”) and a control device using them.

  With only feedback control such as PID control, for example, when a predictable disturbance is applied, the manipulated variable is not adjusted unless the controlled variable is changed by that, so a delay in response cannot be avoided. Therefore, the control amount is disturbed.

  For this reason, feedforward control may be added so as to obtain a desired control response. (For example, refer to Patent Document 1).

JP 2000-227801 A

  In the feedforward control, a correction operation amount that is an FF correction amount is added to the operation amount from the control unit so as to cancel the influence of the predictable disturbance.

  It is conceivable to obtain such a correction operation amount by iterative calculation by simulation based on the disturbance waveform and the control amount from the control target model. To obtain a highly accurate correction operation amount, for example, a target value or the like When the operating conditions differ, it is preferable to use the disturbance waveform measured for each operating condition and the identified controlled object model.

  However, each time the operating conditions such as the target value are different, it takes time to collect data for operating the actual device and measuring the disturbance waveform or identifying the control target model. There is a problem of consuming the above.

  The present invention has been made in view of the above-described problems, and the disturbance waveform and the control target model can be obtained without performing measurement for identifying the disturbance waveform and the control target model every time the operation conditions are different. It is an object of the present invention to make it possible to estimate the parameters, and to estimate the feedforward correction amount and feedforward control using them.

  (1) The disturbance estimation apparatus of the present invention is a disturbance estimation apparatus that estimates a disturbance waveform applied to a control target, and a storage unit that stores in advance a plurality of disturbance waveforms respectively measured under a plurality of operating conditions; An estimation unit configured to estimate a disturbance waveform of another operation condition different from the plurality of operation conditions based on the plurality of disturbance waveforms of the storage unit.

  The operating conditions refer to conditions for operating a control target, for example, a packaging machine, a heat treatment apparatus, a molding apparatus, various machines, a plant, etc., for example, a target value such as a set temperature, a mold type, and a processing speed. Various conditions such as.

  The plurality of operating conditions are preferably two different operating conditions.

  According to the disturbance estimation device of the present invention, since the disturbance waveform under different operating conditions is estimated from a plurality of disturbance waveforms measured under a plurality of pre-stored operating conditions, the device is actually operated every time the operating conditions are different. There is no need to measure the disturbance waveform.

  (2) In one embodiment of the disturbance estimation device of the present invention, the operation condition includes at least a target value condition, and the estimation unit uses the disturbance waveform of the other operation condition as the plurality of disturbance waveforms. Is to be interpolated.

  Here, the interpolation may be either interpolation or extrapolation.

  According to this embodiment, a disturbance waveform of another operating condition can be estimated by interpolation from a plurality of disturbance waveforms respectively measured under a plurality of operating conditions having different target values such as set temperature.

  (3) A controlled object model estimation apparatus of the present invention is a controlled object model estimating apparatus that estimates parameters of a controlled object model, and is based on the parameters of the controlled object model identified under at least one operating condition. The parameter of the control object model of other driving conditions different from one driving condition is estimated.

  When estimating a parameter to be controlled in another operating state based on a parameter to be controlled that is identified under one operating condition, the relationship between the operating condition and the parameter may be estimated by linear approximation .

  According to the controlled object model estimation device of the present invention, the parameters of the controlled object model with different operating conditions are estimated based on the parameters of the controlled object model identified under at least one operating condition. There is no need to actually operate the device and identify the parameters of the controlled object model.

  (4) In another embodiment of the controlled object model estimation device of the present invention, the operating condition includes at least a target value condition, the parameter of the controlled object model is a dead time, and each of the operating condition models has a plurality of operating conditions. The parameter of the control target model of the other operating condition is interpolated from the parameters of the plurality of control target models to be identified.

  The parameters of the control target model other than the dead time may be made common regardless of the operating conditions.

  According to this embodiment, the dead time of a control target model of another operating condition is estimated by interpolation from the dead times of a plurality of controlled object models that are respectively identified under a plurality of operating conditions having different target values such as set temperatures. Can do.

  (5) A feedforward amount estimating apparatus according to the present invention includes at least one of a disturbance estimating apparatus according to the present invention and a controlled object model estimating apparatus according to the present invention, and is a disturbance estimated by the disturbance estimating apparatus. Using at least one of the waveform and the controlled object model for which the parameter is estimated by the controlled object model estimation device, the calculation is repeatedly performed while changing the feedforward correction amount based on the controlled variable from the controlled object model. The feedforward correction amount is estimated according to the optimization method.

  The feedforward amount is not limited to the correction operation amount, and may be a correction target value.

  Optimization methods include gradient methods such as Newton's method and steepest descent method, and metaheuristic methods such as GA and PSO.

  According to the feedforward amount estimation device of the present invention, the feedforward correction amount is estimated using at least one of the disturbance waveform estimation device according to the present invention and the controlled object model estimation device according to the present invention. In order to estimate the feedforward correction amount each time, it is not necessary to actually operate the apparatus to measure the disturbance waveform and to identify the parameters of the controlled object model.

  (6) The control device of the present invention includes a control unit that receives a control amount and a target value from a control target and outputs an operation amount, and is estimated by the feedforward amount estimation device according to claim 5. The feedforward correction amount is used to correct at least one of the target value input to the control unit and the operation amount output from the control unit.

  The control device may incorporate a feedforward amount estimation device, or may use a feedforward correction amount estimated by the feedforward amount estimation device without incorporating a feedforward amount estimation device.

  According to the control device of the present invention, by correcting the operation amount using the feedforward correction amount estimated by the feedforward amount estimation device according to the present invention, feedforward control is performed so as to cancel the disturbance, or By correcting the target value using the feedforward correction amount, it is possible to perform feedforward control so as to improve the target value response characteristics, and in order to estimate the feedforward correction amount every time the operating conditions are different, It is not necessary to actually operate the apparatus to measure the disturbance waveform and to identify the parameters of the controlled object model.

  According to the present invention, since a disturbance waveform under different operating conditions is estimated from a plurality of disturbance waveforms measured under a plurality of operating conditions stored in advance, each time the operating conditions differ, the apparatus is actually operated to generate a disturbance waveform. In addition, the parameters of the control target model with different operating conditions are estimated based on the parameters of the control target model identified under at least one operating condition. There is no need to operate the device and identify the parameters of the controlled object model.

  As a result, the time required for obtaining the disturbance waveform and the controlled object model is shortened, and the time for obtaining the feedforward correction amount using these is also shortened.

It is a lineblock diagram of a system provided with a temperature regulator concerning an embodiment of the present invention. It is a block diagram at the time of the feedforward correction amount estimation of the temperature controller of FIG. It is a block diagram at the time of disturbance waveform acquisition of the temperature controller of FIG. It is a figure which shows the disturbance waveform of setting temperature 100 degreeC. It is a figure which shows the disturbance waveform of preset temperature 100 degreeC and 300 degreeC, and the estimated disturbance waveform of preset temperature 200 degreeC. Control amount when feed-forward control is performed at a set temperature of 200 ° C. using a FF correction amount obtained using a disturbance waveform at a set temperature of 100 ° C. (solid line) and when the feed-forward control is not performed (dashed line) It is a figure which shows the operation amount. When the feedforward control at the set temperature 200 ° C. is performed using the FF correction amount obtained using the disturbance waveform at the set temperature 200 ° C. estimated by the embodiment (solid line) and when the feedforward control is not performed (broken line) It is a figure which shows the control amount and operation amount of (). It is a figure which shows the relationship between the dead time of a control object model, and preset temperature. Control when feed-forward control is performed at a set temperature of 200 ° C. (solid line) and when feed-forward control is not performed (dashed line) using the FF correction amount obtained using the control target model at the set temperature of 100 ° C. It is a figure which shows quantity and operation quantity. Control amount when feedforward control is performed at a set temperature of 200 ° C. using the FF correction amount obtained using the control target model estimated by the embodiment (solid line) and when feedforward control is not performed (dashed line) It is a figure which shows operation amount.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a configuration diagram of a temperature control system including a temperature regulator as a control device according to an embodiment of the present invention.

  The temperature controller 1 of this embodiment controls the temperature of the controlled object 2 so as to be a set temperature that is a target value, and a predictable fixed disturbance 3 is applied to the controlled object 2. .

  As the control object 2 to which the fixed disturbance 3 is applied, for example, a hot plate for heat-treating the wafer can be assumed. As the fixed disturbance, the heat of the hot plate is periodically placed on the hot plate. It is possible to envisage the wafer taking away.

  The temperature controller 1 of this embodiment includes a control unit 4 that performs a PID calculation and outputs an operation amount based on a deviation between a detected temperature that is a control amount from the control target 2 and a set temperature that is a target value; An operation amount correction unit 5 that outputs a correction operation amount, which is an FF correction amount obtained by repetitive calculation as described later, so as to cancel (cancel) the disturbance according to the timing of the disturbance application; The temperature of the controlled object 2 is controlled by the operation amount obtained by adding the operation amount from the control unit 4 and the correction operation amount.

  In this embodiment, a correction operation amount that is an FF correction amount in the operation amount correction unit 5 is obtained by a simulation calculation using a disturbance waveform and a control target model.

  FIG. 2 is a block diagram of the temperature controller 1 in the case of obtaining this correction operation amount, and the same reference numerals are given to the portions corresponding to FIG.

  The temperature controller 1 includes a model 2a of the control target 2 in FIG. 1, a disturbance estimation device 6 that estimates a disturbance waveform as described later, and an FF correction amount that is repeatedly calculated by changing the FF correction amount. The FF correction amount estimation means 7 to be estimated, the changed FF correction amount are output to the addition unit 8, the FF correction amount storage means 9 for storing the finally estimated FF operation amount, and the control unit 4 An operation amount storage unit 10 that stores an operation amount obtained by adding the operation amount and the FF correction amount is provided, and an FF correction amount estimation device that estimates the FF correction amount is configured by these. These are constituted by, for example, a microcomputer.

  In this embodiment, the FF correction amount estimation device is built in the temperature controller 1. However, as another embodiment of the present invention, the FF correction amount estimation device is configured by a personal computer or the like separate from the temperature controller 1. Then, the FF correction amount estimated by the simulation calculation may be set in the temperature controller 1.

  The control target model 2a of this embodiment is a model identified based on input / output data measured by operating an actual apparatus in the absence of disturbance. For example, a model approximated by secondary delay + dead time It is.

  The disturbance waveform estimated by the disturbance estimation device 6 is subtracted by the subtraction unit 11 from the control amount estimated by the control target model 2a and input to the FF correction amount estimation means 7.

  The FF correction amount estimation means 7 corrects the FF correction amount according to the difference between the disturbance waveform of the disturbance estimation device 6 and the control amount. Specifically, for example, the size of the FF correction amount is optimized using an optimization method such as Newton's method or GA (genetic algorithm) so that the sum of squared deviations over the entire disturbance section is minimized. . The evaluation index is not limited to the sum of square deviations, and settling time, maximum deviation, or the like may be used.

  When the operation amount is saturated by adding the operation amount from the control unit 4 and the FF correction amount, the current operation amount from the operation amount storage unit 10 is input to the FF correction amount estimation unit 7. This is dealt with by extending the time of the FF manipulated variable.

  As described above, the control target model 2a and the disturbance estimation device 6 are used to repeatedly perform the calculation while changing the FF correction amount based on the control amount and the disturbance waveform, and obtain the FF correction amount according to the optimization method. Yes. The obtained FF correction amount is given to the operation amount correction unit 5 in FIG. 1 described above, and is used to correct the operation amount from the control unit 4 as described above.

  In order to obtain a highly accurate FF correction amount, for example, for each set temperature, the apparatus is actually operated to measure a disturbance waveform, and the measured disturbance waveform is used to obtain the FF correction amount. Is preferred.

  However, if the disturbance waveform is measured by actually operating the apparatus for each set temperature, there is a problem that measurement takes time and material is wasted.

  Therefore, in the disturbance estimation device 6 of this embodiment, two types of first and second disturbance waveforms respectively measured at two first and second set temperatures are stored in the control amount storage unit 12 in advance. When operating at a third set temperature different from the first and second set temperatures, the disturbance interpolation unit 13 interpolates the disturbance waveform of the third set temperature.

  FIG. 3 is a block diagram of the main part in the case where the first and second disturbance waveforms are learned and stored in the control amount storage unit 12, and the same parts as those in FIGS. 1 and 2 are the same. The reference sign is attached.

  First, the device to be controlled 2 is actually operated at a first set temperature, for example, a set temperature of 100 ° C., and the temperature controller 1 controls the temperature, and a disturbance waveform that is a change in control amount due to the fixed disturbance 3 is generated. Measure and store in the control amount storage unit 12.

  FIG. 4 shows a disturbance waveform at a set temperature of 100 ° C. In FIG. 4, the dead time L1 and the period from when the control amount decreases as described later until it returns to the set temperature again, For example, it is divided into six periods, the first and second periods are T1 (1) and T1 (2), and the control amounts at the end points of the first and second periods are PV1 (1) and PV1 (2), respectively. Show.

  The control amount storage unit 12 stores the first disturbance waveform shown in FIG. 4 in the case of the set temperature of 100 ° C., and similarly, is the second set temperature, for example, the set temperature of 300 ° C. In this case, the second disturbance waveform is stored in advance.

  Referring again to FIG. 2, the disturbance interpolation unit 13 of the disturbance estimation device 6 uses a third set temperature different from the first and second set temperatures, for example, a set temperature, as the set temperature that is a target value. When 200 ° C. is given, the third disturbance waveform, which is the disturbance waveform at the third set temperature, is estimated by interpolation based on the first and second disturbance waveforms in the control amount storage unit 12.

  FIG. 5 is a diagram for explaining the interpolation of the third disturbance waveform. FIG. 5A shows the first disturbance waveform when the set temperature is 100 ° C., and FIG. FIG. 2C shows a third disturbance waveform in the case of the set temperature of 200 ° C. estimated by interpolation.

  The first disturbance waveform in FIG. 10A and the second disturbance waveform in FIG. 10B are stored in advance in the control amount storage unit 12 as described above.

  Based on the dead times L1 and L2 of each disturbance waveform, the dead time of the third disturbance waveform is calculated according to the following equation. Further, a period from when the control amount of each disturbance waveform starts to decrease until it returns to the set temperature is divided into, for example, six first to sixth periods, and the temperature and time at the end point of the kth period are used. The temperature and time at the end point of the kth period of the third disturbance waveform are calculated according to the following formula.

Waste time = (L1 + L2) / 2
kth time = {T1 (k) + T2 (k)} / 2
kth temperature = {PV1 (k) + PV2 (k)} / 2
As described above, the third disturbance waveform at the set temperature of 200 ° C. is estimated by linear interpolation as shown by the solid line in FIG.

  6 (a) and 6 (b) perform feedforward control at a set temperature of 200 ° C. using the FF correction amount obtained as shown in FIG. 2 using the measured disturbance waveform at the set temperature of 100 ° C. 7 (a) and 7 (b) show the disturbance waveform estimated by this embodiment, that is, the measured disturbance temperature waveform at a set temperature of 100 ° C. and the measured set temperature. It shows the control amount and the operation amount when performing the feedforward control at the set temperature of 200 ° C. obtained using the FF correction amount obtained by using the disturbance waveform at the set temperature of 200 ° C. interpolated from the disturbance waveform at 300 ° C. is there.

  6 (a) and 7 (a), the thick solid line indicates the control amount in the feedforward control, the broken line indicates the disturbance waveform, and FIG. 6 (a) indicates the disturbance waveform at the set temperature of 100 ° C. FIG. 7A shows a disturbance waveform at the set temperature of 200 ° C. interpolated as described above.

  In FIGS. 6B and 7B, a thick solid line indicates an operation amount in the feedforward control, and a broken line indicates an operation amount when the feedforward control is not performed.

  In FIG. 6A, a disturbance waveform having a set temperature of 100 ° C. is used with respect to a set temperature of 200 ° C. Since the disturbance waveform is not correct, the dead time is roughly estimated, and therefore the FF correction amount is increased. And overshoot occurs. On the other hand, in FIG. 7A using a disturbance waveform with a set temperature of 200 ° C. obtained by interpolation, overshoot is suppressed.

(Embodiment 2)
In the above-described embodiment, disturbance waveforms having different set temperatures are estimated by interpolation. However, as another embodiment of the present invention, parameters of the control target model 2a having different set temperatures may be estimated by interpolation.

  That is, when the model 2a of the controlled object 2 is approximated by, for example, a second order delay + dead time, the dead time greatly affects the dynamic characteristics, and therefore, the dead time is linearly interpolated. The second order delay is common.

  In this case, the input / output data for determining the dead time of the control target model 2a is not measured at each set temperature, but the input / output data is collected at two different first and second set temperatures. By identifying the parameters of the control target model based on the input / output data, the dead time of the control target model at other set temperatures is interpolated as follows.

  For example, as shown in FIG. 8, the dead time of the control target model with the set temperature of 200 ° C. from the dead time of 20 seconds of the control target model with the set temperature of 100 ° C. and the dead time of 12 seconds of the control target model with the set temperature of 300 ° C. 16 seconds is obtained by linear interpolation.

  This eliminates the need to collect data by operating an actual apparatus in order to identify the parameters of the controlled object model for each set temperature.

  9A and 9B, feedforward control at a set temperature of 200 ° C. was performed using the FF correction amount obtained by using the control target model at the set temperature of 100 ° C. with a dead time of 20 seconds. 10 (a) and 10 (b) show the control target model in which the dead time estimated by this embodiment is 16 seconds, that is, the control target having a set temperature of 100 ° C. Feed-forward control at a set temperature of 200 ° C. using the FF correction amount obtained by using the control target model interpolated from the dead time of the model (20 seconds) and the dead time (12 seconds) of the control target model at the set temperature of 300 ° C. This shows the control amount and the operation amount when the operation is performed.

  9A and 10A, a thick solid line indicates a control amount in the feedforward control, and indicates a control amount when the feedforward control is not performed.

  In FIGS. 9B and 10B, the thick solid line indicates the operation amount in the feedforward control, and the broken line indicates the operation amount when the feedforward control is not performed.

  In FIG. 10, since the identification of the control object is correctly performed as compared with FIG. 9, it can be seen that the hunting of the control amount is suppressed.

  In the above-described embodiment, the dead time of the control target model of two set temperatures is used. However, as another embodiment of the present invention, the dead time of the control target model of one set temperature is used to set other set temperatures. The dead time may be estimated by interpolation. In this case, the linear relationship between the set temperature and the dead time shown in FIG. 8 described above may be used to interpolate from the dead time of the control target model at the one set temperature.

  Although the disturbance response has been described in the above-described embodiment, the present invention can be similarly applied to the target value response. The correction target value is estimated as the FF correction amount, and the target value is corrected. Good.

  The present invention is useful for adjusting the feedforward amount of the control device.

DESCRIPTION OF SYMBOLS 1 Temperature controller 2 Control object 2a Control object model 4 Control part 6 Disturbance estimation apparatus 7 FF correction amount estimation means 12 Control amount memory | storage part 13 Disturbance interpolation part

Claims (6)

A disturbance estimation device for estimating a disturbance waveform applied to a controlled object,
A storage unit in which a plurality of disturbance waveforms respectively measured under a plurality of operating conditions are stored;
Based on a plurality of disturbance waveforms in the storage unit, an estimation unit that estimates a disturbance waveform of another operation condition different from the plurality of operation conditions;
A disturbance estimation device comprising: The operating conditions include at least a target value condition,
The disturbance estimation device according to claim 1, wherein the estimation unit interpolates a disturbance waveform of the other operation condition from the plurality of disturbance waveforms. A control object model estimation device for estimating a parameter of a control object model,
A controlled object model estimation device that estimates a parameter of a controlled object model under another operating condition different from the one operating condition based on a parameter of the controlled object model identified under at least one operating condition. The operating conditions include at least a target value condition,
The parameter of the controlled object model is dead time,
The controlled object model estimation apparatus according to claim 3, wherein the parameter of the controlled object model of the other operating condition is interpolated from the parameters of the controlled object model respectively identified by the plurality of operating conditions. The disturbance estimation device according to claim 1 or 2, and the estimation device of at least one of the control target model estimation device according to claim 3 or 4,
A feedforward correction amount based on a control amount from a control target model using at least one of a disturbance waveform estimated by the disturbance estimation device and a control target model whose parameter is estimated by the control target model estimation device A feedforward amount estimation device that repeatedly performs an operation while changing the value and estimates a feedforward correction amount according to an optimization method. A control unit and a target value from a control target are input, and a control unit that outputs an operation amount is provided.
The feedforward correction amount estimated by the feedforward amount estimation device according to claim 5 is used to correct at least one of the target value input to the control unit and the operation amount output from the control unit. A control device characterized by that.

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