JP2020021299A - Control apparatus and control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize support for appropriately adjusting a feed forward start timing. SOLUTION: A control device has an operation amount calculation unit 1 for calculating an operation amount MV by inputting a set value SP and a control amount PV, and an operation amount after time TH1 has elapsed from the time when the operation amount addition value FF_P is acquired. The operation amount calculation unit 4 that calculates the operation amount addition amount MV_P that converges to the zero value after approaching the addition value FF_P, the operation amount change unit 6 that adds the operation amount addition amount MV_P to the operation amount MV, and the operation amount addition amount. As a result of the output of the MV_P, if the increase width of the control amount PV exceeds the specified value before the decrease of the control amount PV appears, the operation amount addition amount MV_P output start timing is determined to be early, and the operation. Judgment unit 10 for determining that the output start timing of the operation amount addition amount MV_P is late when the decrease width of the control amount PV exceeds the specified value before the increase of the control amount PV appears as a result of the output of the amount addition amount MV_P. To prepare for. [Selection diagram] Fig. 1

Description

  The present invention relates to a technique for additionally applying feedforward control to a feedback controller, and more particularly to a control device and a control method suitable for executing arbitrary operation amount addition or operation amount subtraction by an operator's operation.

  A method of adding feedforward (Feedforward) to PID control, which is a typical feedback control (hereinafter referred to as feedforward + feedback control), has been proposed (see Patent Document 1).

  The inventor of the present invention has applied a feed-forward + feedback control to a heating apparatus as shown in FIG. 13 in which the feedforward amount MV_P is asymptotically converged to zero in order to improve practicality. A forward method (Japanese Patent Application No. 2017-233250) was proposed.

  13 includes a heat treatment furnace 100 for heating a workpiece to be processed, an electric heater 101, a temperature sensor 102 for measuring the temperature in the heat treatment furnace 100, and a temperature controller for controlling the temperature in the heat treatment furnace 100. 103, a power regulator 104, a power supply circuit 105, and a PLC (Programmable Logic Controller) 106 for controlling the entire heating device. The temperature controller 103 calculates the manipulated variable MV such that the temperature PV (control amount) measured by the temperature sensor 102 matches the temperature set value SP. The power regulator 104 determines power according to the manipulated variable MV, and supplies the determined power to the electric heater 101 through the power supply circuit 105.

Next, a technique proposed by the inventor in Japanese Patent Application No. 2017-233250 will be described using a block diagram of a control system in FIG. P in FIG. 14 indicates a control target.
The operation amount calculation unit 1 receives the set value SP and the control amount PV, and performs a PID control calculation such as the following transfer function equation so that the control amount PV matches the set value SP, and performs the operation amount MV Is calculated.
MV = (100 / Pb) {1+ (1 / Tis) + Tds} (SP-PV)
... (1)
Pb is a proportional band, Ti is an integration time, Td is a differentiation time, and s is a Laplace operator.

When the operation amount addition value FF_P (FF_P ≠ 0), which is the target value of the addition amount for feedforward with respect to the operation amount MV, is input, the addition amount calculation unit 4 approaches the operation amount addition value FF_P and then returns to a zero value. And the manipulated variable addition amount MV_P that gradually converges. Specifically, the addition amount calculation unit 4 calculates the operation amount addition amount MV_P using the following transfer function equation.
MV_P = ｛Kxs / (1 + Tfs) ² ｝ FF_P (2)

  Tf in equation (2) is a parameter that defines the time during which the manipulated variable addition amount MV_P gradually converges. Kx is a parameter that defines the magnitude of the feed forward. The addition amount calculation unit 4 may set a value of β times the parameter Tf to Kx (Kx = βTf, β is, for example, 2.75). FIG. 15 shows an example of a change in the operation amount addition amount MV_P. In the example of FIG. 15, the operation amount addition value FF_P = 50%, the parameter Tf = 100 sec. And

When the manipulated variable subtraction value FF_M (FF_M ≠ 0), which is the target value of the subtraction amount for the feedforward with respect to the manipulated variable MV, is input, the subtraction amount calculation unit 5 approaches the manipulated variable subtraction value FF_M and returns to a zero value. The operation amount subtraction amount MV_M that gradually converges is calculated. Specifically, the subtraction amount calculation unit 5 calculates the operation amount subtraction amount MV_M by the following transfer function equation.
MV_M = ｛Kxs / (1 + Tfs) ² ｝ FF_M (3)

Tf in equation (3) is a parameter that defines the time during which the manipulated variable subtraction amount MV_M gradually converges. The operation amount changing unit 6 adds the operation amount addition amount MV_P calculated by the addition amount calculation unit 4 to the operation amount MV calculated by the operation amount calculation unit 1, and further calculates the operation amount calculated by the subtraction amount calculation unit 5. The result obtained by subtracting the amount subtraction amount MV_M is calculated as an operation amount MV_F.
MV_F = MV + MV_P−MV_M (4)

  The limit processing unit 7 performs lower limit processing for limiting the operation amount MV_F calculated by the operation amount changing unit 6 to a value equal to or more than a predetermined operation amount lower limit OL, and sets the operation amount MV_F to a value equal to or less than a predetermined operation amount upper limit OH. An upper limit process is performed to limit the value. The manipulated variable MV_F 'subjected to the limit processing by the limit processing unit 7 is output to the control target P.

  Next, a problem of feedforward + feedback control disclosed in Patent Document 1 will be described. As for the manipulated variable output by the PID calculation of the temperature controller, output saturation is determined only by the manipulated variable MV calculated by the temperature controller, and anti-reset windup processing for the integration operation is performed. Therefore, it is necessary to solve the problem that the temperature controller does not function properly if the feedforward portion that is constantly remaining is added to the feedback portion (the operation amount MV by the PID calculation). For example, when the temperature controller outputs a manipulated variable MV = 60% which has sufficient margin for output saturation, if a 50% feedforward component is added, the output becomes 110%, and the output exceeds 100%. Although it is saturated, a problem occurs that the anti-reset windup process is not executed as a temperature controller.

  In the feedforward + feedback control disclosed in Patent Literature 1, the above problem occurs. However, according to the technique described in FIGS. 14 and 15, the feedforward component is gradually added to the feedback component. As a result, the influence on the PID calculation is temporarily and continuously generated, so that the occurrence of the above-described problem can be reduced.

On the other hand, a normal operator (control technology user) who is not an expert in control technology can rarely appropriately evaluate the execution result of the feedforward control, but the timing to start the operation of adding the feedforward control is not appropriate. It must be adjusted while evaluating. However, this timing adjustment is a problem of the timing between the output of the manipulated variable addition amount MV_P or the manipulated variable subtraction amount MV_M and the application of the disturbance. Deteriorates.
It is difficult for a normal operator who is not an expert in control technology to appropriately adjust the output start timing of the manipulated variable addition amount MV_P or the manipulated variable subtraction amount MV_M to obtain a sufficient feedforward control effect.

JP 2007-102816 A

  SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and is intended to appropriately adjust a feedforward start timing when feedforward control is additionally applied to a general-purpose feedback controller (for example, a temperature controller of PID control). It is an object to provide a control device and a control method capable of supporting.

  The control device of the present invention includes an operation amount calculation unit configured to calculate an operation amount by PID control calculation with a set value and a control amount as inputs, and an external input when a disturbance application is determined. An addition value obtaining unit configured to obtain an operation amount addition value that is a target value of the feedforward addition amount with respect to the operation amount; and a first time from when the operation amount addition value that is different from zero is obtained. After an elapse of the operation amount, an addition amount calculation unit configured to calculate an operation amount addition amount that gradually converges to a zero value after approaching the operation amount addition value, and an operation calculated by the operation amount calculation unit An operation amount changing unit configured to add the operation amount addition amount calculated by the addition amount calculation unit to the operation amount to change the operation amount; and an operation amount changed by the operation amount change unit. Operate above the lower limit A limit processing unit configured to perform a limit process for limiting the value to a value equal to or less than the amount upper limit value; an operation amount output unit configured to output the limited amount of operation to a control target; As a result of the calculation and output of the manipulated variable addition amount, if the increase in the control amount with respect to the set value exceeds a first specified value before the decrease of the control amount appears, A first determining unit configured to determine that the output start timing is early; and calculating and outputting the operation amount addition amount with respect to disturbance application, as a result of the control amount before the rise of the control amount appears. A second determining unit configured to determine that the output start timing of the manipulated variable addition amount is late when a decrease width with respect to the set value exceeds a second prescribed value; and the first and second determination units. Judgment part judgment result It is characterized in further comprising a configured determination result display portion as presented.

  Further, in one configuration example of the control device of the present invention, when the calculation and output of the operation amount addition amount are performed, an increasing width of the control amount with respect to the set value has reached the first specified value. A second time from the point in time until the control amount starts to decrease is measured, and when the first determination unit determines that the output start timing of the operation amount addition amount is early, the first time An update unit configured to add the second time and update the first time is further provided.

  Further, the control device of the present invention is configured such that an operation amount calculation unit configured to calculate an operation amount by PID control calculation with a set value and a control amount as inputs is input from the outside when the disturbance application is determined. A subtraction value acquisition unit configured to acquire a manipulated variable subtraction value which is a target value of a subtraction amount for feedforward with respect to the manipulation amount, and a first value obtained when the manipulation amount subtraction value different from zero value is acquired. After the time elapses, the subtraction amount calculation unit configured to calculate the operation amount subtraction amount that gradually converges to zero value after approaching the operation amount subtraction value, and the operation amount calculation unit calculates the subtraction amount calculation unit. An operation amount change unit configured to subtract the operation amount subtraction amount calculated by the subtraction amount calculation unit from the operation amount to change the operation amount, and an operation amount changed by the operation amount change unit. MV lower limit A limit processing unit configured to perform limit processing for limiting the operation amount to a value equal to or less than the upper limit of the operation amount, an operation amount output unit configured to output the limited operation amount to a control target, As a result of the calculation and output of the manipulated variable subtraction amount with respect to the application of the disturbance, if the decrease width of the control amount with respect to the set value exceeds a first specified value before the increase of the control amount appears, the manipulated variable A first determination unit configured to determine that the output start timing of the subtraction amount is early; and that the control is performed before a decrease in the control amount appears as a result of calculation and output of the operation amount subtraction amount with respect to disturbance application. A second determining unit configured to determine that the output start timing of the manipulated variable subtraction amount is late when an increasing range of the amount with respect to the set value exceeds a second specified value; Of the second judgment part It is characterized in further comprising a configured judgment result presentation unit to present the cross-sectional results.

  Further, in one configuration example of the control device of the present invention, when the calculation and output of the manipulated variable subtraction amount are being performed, a decrease width of the control amount with respect to the set value has reached the first specified value. A second time from the point in time until the control amount starts to increase is measured, and when the first determination unit determines that the output start timing of the operation amount subtraction amount is early, the first time is set to the first time. An update unit configured to add the second time and update the first time is further provided.

  Further, the control method of the present invention includes a first step of calculating an operation amount by PID control calculation with a set value and a control amount as inputs, and a step of inputting the operation amount from the outside when the disturbance application is determined. A second step of obtaining an operation amount addition value that is a target value of the addition amount for feedforward, and the operation amount after a first time has elapsed from the acquisition of the operation amount addition value different from zero. A third step of calculating an operation amount addition amount that gradually converges to a zero value after approaching the addition value; and an operation amount addition calculated in the third step to the operation amount calculated in the first step. A fourth step of changing the manipulated variable by adding the manipulated variable and a limit process of restricting the manipulated variable changed in the fourth step to a value equal to or greater than the manipulated variable lower limit and less than or equal to the manipulated variable upper limit. Step and this A sixth step of outputting the manipulated variable subjected to the limit processing to the control target, and calculating and outputting the manipulated variable addition amount with respect to the application of disturbance, as a result of the control amount with respect to the set value before the decrease of the control amount appears. As a result of the seventh step of determining that the output start timing of the manipulated variable addition amount is early when the rise width exceeds the first specified value, and calculating and outputting the manipulated variable addition amount with respect to disturbance application, An eighth step of judging that the output start timing of the manipulated variable addition amount is late if the decrease width of the control amount with respect to the set value exceeds a second specified value before the increase of the control amount appears; , A ninth step of presenting the determination results of the seventh and eighth steps.

  Further, the control method of the present invention includes a first step of calculating an operation amount by PID control calculation with a set value and a control amount as inputs, and a step of inputting the operation amount from the outside when the disturbance application is determined. A second step of obtaining a manipulated variable subtraction value that is a target value of the feedforward subtraction quantity, and after the first time elapses from the acquisition of the manipulated variable subtraction value that is different from zero, A third step of calculating an operation amount subtraction amount that gradually converges to a zero value after approaching the subtraction value; and an operation amount subtraction calculated in the third step from the operation amount calculated in the first step. A fourth step of changing the manipulated variable by subtracting the manipulated variable, and a fifth step of performing a limit process for limiting the manipulated variable changed in the fourth step to a value equal to or greater than the manipulated variable lower limit and equal to or less than the manipulated variable upper limit. Steps and A sixth step of outputting the manipulated variable subjected to the limit processing to the control object, and calculating and outputting the manipulated variable subtraction quantity with respect to the application of disturbance, as a result of the control quantity being increased before the control quantity rises. A seventh step of determining that the output start timing of the manipulated variable subtraction amount is early when the decrease width of the manipulated variable exceeds a first specified value, and calculating and outputting the manipulated variable subtraction amount in response to disturbance application. An eighth step of judging that the output start timing of the manipulated variable subtraction amount is late if the increase amount of the control amount relative to the set value exceeds a second specified value before the decrease of the control amount appears. And a ninth step of presenting the judgment results of the seventh and eighth steps.

  According to the present invention, by providing the addition value acquisition unit, the addition amount calculation unit, and the operation amount change unit, when the feedforward control is additionally applied to the feedback control by the operation amount calculation unit, a problem with the feedback control is reduced. Occurrence can be reduced. Furthermore, in the present invention, the operator appropriately adjusts the output start timing of the operation amount addition amount by providing the first and second determination units that determine whether the output start timing of the operation amount addition amount is early or late. Support can be realized.

  Further, in the present invention, by providing the update unit, when the first determination unit determines that the output start timing of the operation amount addition amount is early, the first time is updated to output the operation amount addition amount. The start timing can be automatically adjusted.

  Further, in the present invention, by providing the subtraction value acquisition unit, the subtraction amount calculation unit, and the operation amount change unit, when the feedforward control is additionally applied to the feedback control by the operation amount calculation unit, a problem for the feedback control can be prevented. Occurrence can be reduced. Furthermore, in the present invention, the operator appropriately adjusts the output start timing of the operation amount subtraction amount by providing the first and second determination units that determine whether the output start timing of the operation amount subtraction amount is early or late. Support can be realized.

  Further, in the present invention, by providing the update unit, when the first determination unit determines that the output start timing of the operation amount subtraction amount is early, the first time is updated to output the operation amount subtraction amount. The start timing can be automatically adjusted.

FIG. 1 is a block diagram illustrating a configuration of a control device according to an embodiment of the present invention. FIG. 2 is a flowchart illustrating a control operation of the control device according to the embodiment of the present invention. FIG. 3 is a flowchart illustrating operations of the determination unit, the determination result presentation unit, and the update unit of the control device according to the embodiment of the present invention. FIG. 4 is a diagram illustrating an example of a change in a control amount and a change in an operation amount when temperature control is performed only by feedback control without executing feedforward control. FIG. 5 is a diagram illustrating an example of a change in the control amount and the operation amount when the temperature is controlled by the control device according to the embodiment of the present invention. FIG. 6 is a diagram illustrating an example of a change in the operation amount addition amount when the temperature is controlled by the control device according to the embodiment of the present invention. FIG. 7 is a diagram illustrating another example of a change in the control amount and the operation amount when the temperature is controlled by the control device according to the embodiment of the present invention. FIG. 8 is a diagram illustrating another example of a change in the operation amount addition amount when the temperature is controlled by the control device according to the embodiment of the present invention. FIG. 9 is a diagram illustrating another example of a change in the control amount and the operation amount when the temperature is controlled by the control device according to the embodiment of the present invention. FIG. 10 is a diagram illustrating another example of a change in the manipulated variable addition amount when temperature control is performed by the control device according to the embodiment of the present invention. FIG. 11 is a diagram illustrating a display example of the determination result presentation unit of the control device according to the embodiment of the present invention. FIG. 12 is a block diagram illustrating a configuration example of a computer that realizes the control device according to the embodiment of the present invention. FIG. 13 is a block diagram illustrating a configuration of the heating device. FIG. 14 is a block diagram of a feedback + feedforward control system. FIG. 15 is a diagram illustrating an example of a change in the operation amount addition amount in the feedback + feedforward control.

[Principle of the invention]
The principle of the present invention will be described using a temperature control system by heating as an example. First, for example, in the case of the manipulated variable addition amount (feedforward amount) MV_P for the temperature drop disturbance, it is possible to optimize the increase amount of the manipulated variable MV only for the feedback control as a guide. It is reasonable to assume that this has been done in advance. Specifically, it is assumed that Kx, Tf, and FF_P have been optimized in Expression (2).

  Based on this premise, if the operation amount addition amount MV_P is on the plus side with respect to the temperature drop disturbance, the feedforward start timing is determined by using whether the temperature drop due to the disturbance application is fast or the temperature increase due to the operation amount addition amount MV_P is fast. You can judge the validity. That is, if the temperature rise of the control target exceeds the specified value (for example, the settling target width) first as a result of the positive feedforward control with respect to the temperature drop disturbance, it can be determined that the feedforward start timing is early. Conversely, if the temperature drop exceeds a specified value first (for example, half or more of the temperature drop in the case of only feedback control), it can be determined that the feed forward start timing is late.

The inventor has conceived that by applying such a determination, it is possible for the operator to realize support for appropriately adjusting the feedforward start timing.
In addition, as long as the feed forward start timing is early, the feed forward start timing can be automatically adjusted based on the time from when the temperature rise starts to when the temperature starts to fall.

[Example]
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram illustrating a configuration of a control device according to the present embodiment. The control device includes an operation amount calculation unit 1 that calculates an operation amount MV by PID control calculation using the set value SP and the control amount PV as inputs, and a feed for the operation amount MV input from the outside when disturbance is determined. An FF addition value acquisition unit 2 for acquiring an operation amount addition value FF_P that is a target value of the forward amount, and a feedforward subtraction amount for the operation amount MV, which is input from the outside when the disturbance application is determined. When the FF subtraction value acquisition unit 3 that acquires the operation amount subtraction value FF_M that is the target value, and when the operation amount addition value FF_P that is different from the zero value is acquired, the operation amount addition value FF_P When the operation amount calculation unit 4 calculates the operation amount addition amount MV_P that gradually converges to a zero value after approaching, and when the operation amount subtraction value FF_M different from the zero value is acquired, a specific After the time TH2 has elapsed, the subtraction amount calculation unit 5 calculates the operation amount subtraction amount MV_M that gradually converges to a zero value after approaching the operation amount subtraction value FF_M, and the operation amount addition amount MV_P is calculated by the addition amount calculation unit 4. Is calculated, the operation amount addition amount MV_P is added to the operation amount MV calculated by the operation amount calculation unit 1, and when the operation amount subtraction amount MV_M is calculated by the subtraction amount calculation unit 5, this operation amount is calculated. An operation amount changing unit 6 that subtracts the amount subtraction amount MV_M from the operation amount MV calculated by the operation amount calculation unit 1, and an operation amount MV_F calculated by the operation amount changing unit 6 is set to an operation amount lower limit OL or more and an operation amount upper limit. A limit processing unit 7 that performs limit processing for limiting the value to a value equal to or less than the value OH, and an operation amount output unit 8 that outputs the operation amount MV_F ′ subjected to the limit processing are provided.

  Further, as a configuration for optimizing the feedforward start timing, the control device sets the control value PV before the fall of the control amount PV appears as a result of the calculation and output of the operation amount addition amount MV_P for the disturbance application. When the increase width with respect to SP exceeds the specified value U1, the determination unit 9 determines that the output start timing of the manipulated variable addition amount MV_P is early, and the control is performed as a result of calculating and outputting the manipulated variable addition amount MV_P with respect to disturbance application. When the decrease amount of the control amount PV with respect to the set value SP exceeds the specified value D1 before the increase of the amount PV, the determination unit 10 that determines that the output start timing of the operation amount addition amount MV_P is late, As a result of the calculation and output of the manipulated variable subtraction amount MV_M, before the rise of the control amount PV appears, the decrease width of the control amount PV with respect to the set value SP becomes the specified value D2. In this case, the determination unit 11 determines that the output start timing of the operation amount subtraction amount MV_M is early, and the control amount before the decrease of the control amount PV appears as a result of the calculation and output of the operation amount subtraction amount MV_M in response to disturbance. A judgment unit 12 that judges that the output start timing of the manipulated variable subtraction amount MV_M is late when the increase width of the PV with respect to the set value SP exceeds the specified value U2, and a judgment result that presents the judgment results of the judgment units 9 to 12. When the presentation unit 13 and the calculation and output of the manipulated variable addition amount MV_P are performed, the time from when the increase of the control amount PV to the set value SP reaches the specified value U1 until the control amount PV starts to decrease is reduced. The time TD1 is measured, and when the determination unit 9 determines that the output start timing of the manipulated variable addition amount MV_P is early, the time TD1 is added to the time TH1 to update the time TH1. 14, when the manipulated variable subtraction amount MV_M is calculated and output, the time TD2 from the time when the decrease width of the control amount PV with respect to the set value SP reaches the specified value D2 until the control amount PV starts to increase. And an update unit 15 that updates the time TH2 by adding the time D2 to the time TH2 when the determination unit 11 determines that the output start timing of the manipulated variable subtraction amount MV_M is early.

Also in this embodiment, the block diagram of the control system is the same as that of FIG. Next, a control operation of the control device according to the present embodiment will be described with reference to FIG.
The set value SP (for example, a temperature set value) is set by an operator of the control device or the like, and is input to the manipulated variable calculator 1 (step S100 in FIG. 2).
The control amount PV (for example, a temperature measurement value) is measured by a measuring device (for example, a temperature sensor that measures the temperature of the object to be heated), and is input to the operation amount calculation unit 1 (step S101 in FIG. 2).

  The operation amount calculation unit 1 receives the set value SP and the control amount PV, and performs a PID control operation such as a transfer function expression shown in Expression (1) so that the control amount PV matches the set value SP. Then, the operation amount MV is calculated (step S102 in FIG. 2).

  The FF addition value obtaining unit 2 obtains an operation amount addition value FF_P that is input from the outside when the disturbance application is determined and is a target value of an addition amount for feedforward with respect to the operation amount MV. If the disturbance application occurs due to a specific operation outside the feedback control system, the time point at which the specific operation is executed is the time point at which the disturbance application is determined. At this time, the influence of the disturbance does not always appear immediately on the feedback control system when the application of the disturbance is determined.

  Similarly, the FF subtraction value acquisition unit 3 acquires an operation amount subtraction value FF_M, which is a target value of a feedforward subtraction amount from the operation amount MV, which is input from the outside when the disturbance application is determined. The FF addition value acquisition unit 2 and the FF subtraction value acquisition unit 3 acquire a value transmitted by communication at a predetermined timing, acquire a value appropriately input by an operator using an input function, FF_P and FF_M are acquired by acquiring values automatically generated in response to a change in the set value SP input to the manipulated variable calculator 1.

  That is, in a system to which the control device of the present embodiment is applied, for example, in order to suppress disturbances assumed during control, the host device operates the control device at a specified timing or at a timing of changing the set value SP. It is conceivable that the amount addition value FF_P and the operation amount subtraction value FF_M are automatically input, or the operator manually inputs the operation amount addition value FF_P and the operation amount subtraction value FF_M during control.

  Further, in the present embodiment, as described above, it is assumed that Kx, Tf, and FF_P in Equation (2) are previously optimized using the amount of increase in the manipulated variable MV when only feedback control is performed. Similarly, in the present embodiment, it is assumed that Kx, Tf, and FF_M in Expression (3) are previously optimized using the amount of decrease in the manipulated variable MV when only feedback control is performed.

  When the FF addition value obtaining unit 2 obtains the operation amount addition value FF_P different from the zero value and the specific time TH1 or more has elapsed (YES in step S103 in FIG. 2), An operation amount addition amount MV_P that gradually converges to a zero value after approaching the operation amount addition value FF_P is calculated by equation (2) (step S104 in FIG. 2). Therefore, the appropriateness of the timing of starting the feed forward is determined depending on the setting of the specific time TH1.

  As described above, Tf in Expression (2) is a parameter relating to the time of the manipulated variable addition amount MV_P. The addition amount calculation unit 4 may set the PID parameter set in the operation amount calculation unit 1, specifically, a value of α times the integration time Ti to Tf (Tf = αTi, and the predetermined value α is, for example, α = 0.1-2.0). As a result, the change of the operation amount MV to which the operation amount addition amount MV_P has been added by the amount of the feedforward substantially coincides with the cycle when the vertical movement of the control occurs. Further, the elapsed time from when the feedforward amount is added to the manipulated variable MV to when the feedforward amount reaches the maximum change amount becomes substantially equal to the time of the parameter Tf.

  Kx in equation (2) is a parameter that defines the magnitude of the feedforward. The addition amount calculation unit 4 may set a value of β times the parameter Tf to Kx (Kx = βTf, and the predetermined value β is, for example, 2.75). As a result, the maximum change amount of the operation amount MV corresponding to the feedforward becomes approximately equal to the operation amount addition value FF_P. Note that the initial value of the manipulated variable addition amount MV_P from when the FF addition value acquisition unit 2 acquires the manipulated variable addition value FF_P until the specific time TH1 elapses is zero.

  When the FF subtraction value acquisition unit 3 acquires the operation amount subtraction value FF_M different from the zero value and the specific time TH2 or more has elapsed (YES in step S105 in FIG. 2), An operation amount subtraction amount MV_M that gradually converges to a zero value after approaching the operation amount subtraction value FF_M is calculated by equation (3) (step S106 in FIG. 2). Therefore, the appropriateness of the feed forward start timing is determined depending on the setting of the specific time TH2.

  Similarly to the addition amount calculation unit 4, the subtraction amount calculation unit 5 may set the value of α times the integration time Ti to Tf (Tf = αTi, and the predetermined value α is, for example, 0.1 to 2.0). Further, the subtraction amount calculation unit 5 may set the value of β times the parameter Tf to Kx (Kx = βTf, and the predetermined value β is, for example, 2.75). As a result, the maximum change amount of the operation amount MV corresponding to the feedforward becomes approximately equal to the operation amount subtraction value FF_M. Note that the initial value of the manipulated variable subtraction amount MV_M from when the FF subtraction value acquisition unit 3 acquires the manipulated variable subtraction value FF_M to when the specific time TH2 has elapsed is zero.

  The operation amount changing unit 6 adds the operation amount addition amount MV_P calculated by the addition amount calculation unit 4 to the operation amount MV calculated by the operation amount calculation unit 1, and further calculates the operation amount calculated by the subtraction amount calculation unit 5. The result obtained by subtracting the amount MV_M is calculated as an operation amount MV_F (step S107 in FIG. 2). The equation for calculating the manipulated variable MV_F is the same as equation (4).

The limit processing unit 7 performs lower limit processing for limiting the operation amount MV_F calculated by the operation amount changing unit 6 to a value equal to or more than a predetermined operation amount lower limit OL, and sets the operation amount MV_F to a value equal to or less than a predetermined operation amount upper limit OH. An upper limit process for limiting the value is performed (step S108 in FIG. 2).
IF MV_F <OL THEN MV_F ′ = OL (5)
IF MV_F> OH THEN MV_F ′ = OH (6)
That is, the limit processing unit 7 sets the operation amount MV_F ′ = OL when MV_F is smaller than the operation amount lower limit OL, and sets the operation amount MV_F ′ = OH when the operation amount MV_F is larger than the operation amount upper limit OH.

  The operation amount output unit 8 outputs the operation amount MV_F 'subjected to the limit processing by the limit processing unit 7 to the control target (step S109 in FIG. 2). The output destination of the operation amount MV_F 'is an operation unit (not shown) such as a heater or a valve. In the case of a heater, the actual output destination of the manipulated variable MV_F 'is a power regulator (not shown) that supplies power to the heater.

  The control device executes the processes of steps S100 to S109 of FIG. 2 in each control cycle until the control is terminated by an instruction of an operator (YES in step S110 of FIG. 2).

  As described above, the manipulated variable addition amount MV_P is a value that gradually converges to a zero value after approaching the manipulated variable addition value FF_P, and the manipulated variable subtraction amount MV_M is a zero value after approaching the manipulated variable subtraction value FF_M. The value gradually converges to. Therefore, after the specific time TH1 or more has elapsed since the FF addition value acquisition unit 2 acquired the operation amount addition value FF_P different from the zero value, the determination is always YES in step S103, and the addition amount calculation unit 4 performs the operation amount addition The calculation of the amount MV_P is repeatedly executed. Since the manipulated variable addition amount MV_P eventually converges to a zero value, the addition amount calculation unit 4 may stop the calculation when the manipulated variable addition amount MV_P reaches the zero value.

  Similarly, after a specific time TH2 or more has elapsed since the FF subtraction value acquisition unit 3 acquired the operation amount subtraction value FF_M different from the zero value, the determination is always YES in step S105, and the subtraction amount calculation unit 5 determines the operation amount. The calculation of the subtraction amount MV_M is repeatedly executed. Since the manipulated variable subtraction amount MV_M eventually converges to a zero value, the subtraction amount calculation unit 5 may stop the calculation when the manipulated variable subtraction amount MV_M reaches the zero value.

  The above operation is equivalent to the technique proposed by the inventor in Japanese Patent Application No. 2017-233250. Next, the operation of the judgment units 9 to 12, the judgment result presentation unit 13, and the update units 14 and 15 of the present embodiment will be described with reference to FIG.

  As a result of the calculation and output of the manipulated variable addition amount MV_P with respect to the application of the disturbance, the determination unit 9 determines that the increase in the control amount PV with respect to the set value SP becomes the specified value U1 before the decrease of the control amount PV, which is the influence of the disturbance, appears. If it exceeds (PV> (SP + U1)) (YES in step S200 in FIG. 3), the output start timing of the manipulated variable addition amount MV_P is early (the feedforward starts with respect to the timing at which the fall of the control amount PV due to the disturbance appears). It is determined that the timing is early (step S201 in FIG. 3). The specified value U1 is set to, for example, a settling target width.

  On the other hand, as a result of the calculation and output of the manipulated variable addition amount MV_P with respect to the application of the disturbance, before the rise of the control amount PV appears, the determination unit 10 determines that the decrease width of the control amount PV with respect to the set value SP due to the disturbance is the specified value D1. (PV <(SP-D1)) (YES in step S202 in FIG. 3), the output start timing of the manipulated variable addition amount MV_P is late (with respect to the timing at which the fall of the control amount PV due to the disturbance appears). It is determined that the feed forward start timing is late (step S203 in FIG. 3). The specified value D1 is, for example, a lower value assumed when the control amount PV falls with respect to the set value SP due to disturbance when temperature control is performed only by feedback control (PID control) without executing feedforward control. It is set to more than half of the descending width.

  As a result of calculation and output of the manipulated variable addition amount MV_P with respect to the application of the disturbance, the increase width of the control amount PV with respect to the set value SP is equal to or less than the specified value U1 (PV ≦ (SP + U1)), and the decrease width of the control amount PV with respect to the set value SP. Is smaller than or equal to the specified value D1 (PV ≧ (SP−D1)), the determination unit 9 does not determine that the output start timing of the manipulated variable addition amount MV_P is early, and the determination unit 10 determines that the output of the manipulated variable addition amount MV_P is Since it is not determined that the start timing is late, it is determined that the output start timing of the manipulated variable addition amount MV_P is appropriate.

  As a result of calculating and outputting the manipulated variable subtraction amount MV_M with respect to the application of the disturbance, the determination unit 11 determines that the decrease width of the control amount PV with respect to the set value SP is equal to or less than the specified value D2 before the rise of the control amount PV, which is the influence of the disturbance, appears. If it exceeds (PV <(SP-D2)) (YES in step S204 of FIG. 3), the output start timing of the manipulated variable subtraction amount MV_M is early (feeding is performed with respect to the timing at which the rise of the control amount PV due to the disturbance appears). It is determined that the forward start timing is early (step S205 in FIG. 3). The specified value D2 is set to, for example, a settling target width.

  As a result of the calculation and output of the manipulated variable subtraction amount MV_M with respect to the application of the disturbance, the determination unit 12 determines that the rise of the control amount PV with respect to the set value SP exceeds the specified value U2 due to the influence of the disturbance before the fall of the control amount PV appears. If (PV> (SP + U2)) (YES in step S206 in FIG. 3), the output start timing of the manipulated variable subtraction amount MV_M is late (the feedforward start timing is relative to the timing at which the rise of the control amount PV due to the disturbance appears). Is slow) (step S207 in FIG. 3). The specified value U2 is assumed to increase when the control amount PV increases with respect to the set value SP due to disturbance when, for example, temperature control is performed only by feedback control (PID control) without performing feedforward control. It is set to a value that is at least half the width.

  As a result of calculating and outputting the manipulated variable subtraction amount MV_M with respect to the application of the disturbance, the decrease width of the control amount PV with respect to the set value SP is equal to or less than a specified value D2 (PV ≧ (SP−D2)), and the control amount PV is set with respect to the set value SP. When the increase width is equal to or less than the specified value U2 (PV ≦ (SP + U2)), the determination unit 11 does not determine that the output start timing of the operation amount subtraction amount MV_M is early, and the determination unit 12 outputs the operation amount subtraction amount MV_M. Since it is not determined that the start timing is late, the result of the determination is that the output start timing of the manipulated variable subtraction amount MV_M is appropriate.

  The judgment result presentation unit 13 presents the judgment results of the judgment units 9 to 12 to the operator (Step S208 in FIG. 3). As a presentation method, for example, there is a method of displaying information indicating the determination results of the determination units 9 to 12 to the operator. Therefore, based on the presentation of the determination result, the operator sets a parameter (time TH1) for determining the output start timing of the operation amount addition amount MV_P or a parameter (time TH2) for determining the output start timing of the operation amount subtraction amount MV_M. Can be adjusted manually.

  Also, the parameters may be updated automatically instead of manually adjusting as follows. Specifically, when the operation amount addition amount MV_P is calculated and output, the updating unit 14 determines when the increase of the control amount PV with respect to the set value SP reaches the specified value U1 (PV = SP + U1). Is measured (step S209 in FIG. 3) until the control amount PV starts to decrease (step S209 in FIG. 3). When the determination unit 9 determines that the output start timing of the manipulated variable addition amount MV_P is early (YES in step S210 in FIG. 3). ), The time TH1 set in the addition amount calculation section 4 is updated to the time of TH1 + TD1 (step S211 in FIG. 3).

  When calculating / outputting the manipulated variable subtraction amount MV_M, the update unit 15 controls the control variable from the time when the decrease width of the control variable PV with respect to the set value SP reaches the specified value D2 (PV = SP−D2). The time TD2 until the PV starts to increase is measured (step S212 in FIG. 3), and when the determination unit 11 determines that the output start timing of the manipulated variable subtraction amount MV_M is early (YES in step S213 in FIG. 3), the subtraction is performed. The time TH2 set in the amount calculation unit 5 is updated to the time TH2 + TD2 (step S214 in FIG. 3).

  The determination units 9 to 12, the determination result presentation unit 13, and the update units 14 and 15 perform the processing of the above steps S 200 to S 214 by acquiring the operation amount addition value FF_P by the FF addition value acquisition unit 2, and 4 when the manipulated variable addition amount MV_P is calculated and output, or when the manipulated variable subtraction value FF_M is acquired by the FF subtraction value acquisition unit 3 and the manipulated variable subtraction amount MV_M is calculated and output by the subtraction amount calculation unit 5. To be implemented.

  FIG. 4 is a diagram illustrating an example of a disturbance response to which the present embodiment is applied. An example of a change in the control amount PV and the operation amount MV when temperature control is performed only by feedback control without performing feedforward control. FIG. The example of FIG. 4 shows a case where a temperature drop disturbance occurs in a state where the set value SP is set at the control amount PV = 300 ° C. The specified value U1 is set to 20 ° C., and SP + U1 = 320 ° C. In addition, since the temperature is lowered to 220 ° C. due to the temperature lowering disturbance, the range of decrease with respect to the set value SP of the controlled variable PV = 300 ° C. is 80 ° C. Therefore, the specified value D1 = 40 ° C., and SP-D1 = 260 ° C.

  FIG. 5 is a diagram showing an example of changes in the control amount PV and the operation amount MV when temperature control is performed with FF_P = 80%, Kx = 38.5, and Tf = 14.0 seconds in the present embodiment, and FIG. FIG. 10 is a diagram showing a change in an operation amount addition amount MV_P in the case (the operation amount subtraction amount MV_M is fixed to 0%).

  In the examples of FIGS. 5 and 6, since the start timing of the feed forward is about 30 seconds later than the appropriate timing, the decrease width of the control amount PV with respect to the set value SP before the increase of the control amount PV (temperature) appears. Exceeds the specified value D1 = 40 ° C. Therefore, the determination unit 10 determines that the output start timing of the manipulated variable addition amount MV_P is late.

  FIG. 7 is a diagram showing an example of changes in the control amount PV and the operation amount MV when temperature control is performed with FF_P = 80%, Kx = 38.5, and Tf = 14.0 seconds in the present embodiment, and FIG. FIG. 10 is a diagram showing a change in an operation amount addition amount MV_P in the case (the operation amount subtraction amount MV_M is fixed to 0%).

  In the examples of FIGS. 7 and 8, since the start timing of the feed forward is earlier than the appropriate timing by about 20 seconds, the increase amount of the control amount PV with respect to the set value SP before the decrease of the control amount PV (temperature) appears. Exceeds the specified value U1 = 20 ° C. Therefore, the determination unit 9 determines that the output start timing of the manipulated variable addition amount MV_P is early. In addition, in the example of FIG. 7, the time TD1 from the time when the increasing amount of the control amount PV to the set value SP reaches the specified value U1 = 20 ° C. until the control amount PV starts to decrease is detected as 20 seconds. As a result, the updating unit 14 updates the time TH1 set in the addition amount calculating unit 4 to a time longer by 20 seconds.

  FIG. 9 is a diagram showing an example of changes in the control amount PV and the operation amount MV when temperature control is performed with FF_P = 80%, Kx = 38.5, and Tf = 14.0 seconds in the present embodiment, and FIG. FIG. 10 is a diagram showing a change in an operation amount addition amount MV_P in the case (the operation amount subtraction amount MV_M is fixed to 0%).

  9 and 10 show a case where the start timing of feed forward is appropriate. The control amount PV is maintained in the range of 260 ° C. to 320 ° C. even by applying a disturbance. Therefore, the determination unit 9 does not determine that the output start timing of the operation amount addition amount MV_P is early, and the determination unit 10 does not determine that the output start timing of the operation amount addition amount MV_P is late. That is, it is determined that the output start timing of the manipulated variable addition amount MV_P is appropriate, and it can be seen that the effect of the feedforward control is sufficiently obtained.

  FIG. 11 is a diagram illustrating a display example of the determination result presentation unit 13. The example of FIG. 11 is a display example corresponding to the examples of FIGS. However, in the example of FIG. 11, the determination result presentation unit 13 displays on the screen 110 the update result by the update unit 14 in addition to the state of increase of the control amount PV and the determination result of the determination unit 9. I have.

  The control device described in the present embodiment can be realized by a computer having a CPU (Central Processing Unit), a storage device, and an interface, and a program that controls these hardware resources. FIG. 12 shows a configuration example of this computer. The computer includes a CPU 300, a storage device 301, and an interface device (hereinafter, abbreviated as I / F) 302. For example, a temperature sensor and a power regulator are connected to the I / F 302. In such a computer, a program for realizing the control method of the present embodiment is stored in the storage device 301. The CPU 300 executes the processing described in the present embodiment according to a program stored in the storage device 301.

  The present invention can be applied to a control device.

  DESCRIPTION OF SYMBOLS 1 ... Operation amount calculation part, 2 ... FF addition value acquisition part, 3 ... FF subtraction value acquisition part, 4 ... Addition amount calculation part, 5 ... Subtraction amount calculation part, 6 ... Operation amount change part, 7 ... Limit processing part, 8: operation amount output unit, 9 to 12: determination unit, 13: determination result presentation unit, 14, 15 ... update unit.

Claims (6)

An operation amount calculation unit configured to calculate an operation amount by PID control calculation using the set value and the control amount as inputs,
An addition value obtaining unit configured to obtain an operation amount addition value that is a target value of an addition amount for feedforward with respect to the operation amount, which is input from the outside when the disturbance application is determined,
After a first time has elapsed from the acquisition of the manipulated variable addition value different from the zero value, a manipulated variable addition amount that gradually converges to a zero value after approaching the manipulated value addition value is calculated. The added amount calculation unit,
An operation amount changing unit configured to change the operation amount by adding the operation amount addition amount calculated by the addition amount calculation unit to the operation amount calculated by the operation amount calculation unit;
A limit processing unit configured to perform a limit process of limiting the operation amount changed by the operation amount changing unit to a value equal to or more than the operation amount lower limit value and equal to or less than the operation amount upper limit value;
An operation amount output unit configured to output the operation amount subjected to the limit processing to a control target;
As a result of the calculation and output of the manipulated variable addition amount with respect to the application of the disturbance, if the increase in the control amount with respect to the set value exceeds a first specified value before the decrease of the control amount appears, the operation amount A first determination unit configured to determine that the output start timing of the addition amount is early;
As a result of the calculation and output of the manipulated variable addition amount with respect to the application of disturbance, when the decrease width of the control amount with respect to the set value exceeds a second specified value before the increase of the control amount, the manipulated variable A second determination unit configured to determine that the output start timing of the addition amount is late;
A control device, comprising: a determination result presentation unit configured to present the determination results of the first and second determination units. The control device according to claim 1,
In a case where the operation amount addition amount is calculated and output, a second period from when the increase amount of the control amount to the set value reaches the first specified value to when the control amount changes to a lower value is set. Is measured, and when the first determination unit determines that the output start timing of the manipulated variable addition amount is early, the second time is added to the first time and the first time is added. A control device, further comprising an updating unit configured to update time. An operation amount calculation unit configured to calculate an operation amount by PID control calculation using the set value and the control amount as inputs,
A subtraction value acquisition unit configured to acquire an operation amount subtraction value that is a target value of a subtraction amount for feedforward with respect to the operation amount, which is input from the outside when the disturbance application is determined,
After a first time elapses from the time when the manipulated variable subtraction value different from the zero value is obtained, the manipulated variable subtraction amount that gradually converges to the zero value after approaching the manipulated variable subtraction value is calculated. Subtracted amount calculation unit,
An operation amount changing unit configured to change the operation amount by subtracting the operation amount subtraction amount calculated by the subtraction amount calculation unit from the operation amount calculated by the operation amount calculation unit;
A limit processing unit configured to perform a limit process of limiting the operation amount changed by the operation amount changing unit to a value equal to or more than the operation amount lower limit value and equal to or less than the operation amount upper limit value;
An operation amount output unit configured to output the operation amount subjected to the limit processing to a control target;
As a result of the calculation and output of the manipulated variable subtraction amount with respect to the application of the disturbance, if the decrease width of the control amount with respect to the set value exceeds a first specified value before the increase of the control amount appears, the manipulated variable A first determination unit configured to determine that the output start timing of the subtraction amount is early;
As a result of the calculation and output of the manipulated variable subtraction amount with respect to the application of disturbance, if the increase in the control amount with respect to the set value exceeds a second specified value before the control amount falls, the manipulated variable A second determination unit configured to determine that output start timing of the subtraction amount is late;
A control device, comprising: a determination result presentation unit configured to present the determination results of the first and second determination units. The control device according to claim 3,
In a case where the operation amount subtraction amount is calculated and output, a second time from when the decrease width of the control amount to the set value reaches the first specified value to when the control amount starts to increase is increased. Is measured, and when the first determination unit determines that the output start timing of the manipulated variable subtraction amount is early, the second time is added to the first time and the first time is added. A control device, further comprising an updating unit configured to update time. A first step of calculating an operation amount by PID control calculation using the set value and the control amount as inputs,
A second step of acquiring an operation amount addition value that is input from the outside when the disturbance application is determined and is a target value of an addition amount for feedforward with respect to the operation amount;
Calculating a manipulated variable addition amount that gradually converges to a zero value after approaching the manipulated value addition value after a first time has elapsed since the acquisition of the manipulated value addition value different from the zero value; Steps and
A fourth step of changing the operation amount by adding the operation amount addition amount calculated in the third step to the operation amount calculated in the first step;
A fifth step of performing limit processing for limiting the manipulated variable changed in the fourth step to a value equal to or greater than the manipulated variable lower limit and equal to or less than the manipulated variable upper limit;
A sixth step of outputting the operation amount subjected to the limit processing to a control target;
As a result of the calculation and output of the manipulated variable addition amount with respect to the application of the disturbance, if the increase of the control amount with respect to the set value exceeds a first specified value before the decrease of the control amount appears, the manipulated variable A seventh step of determining that the output start timing of the addition amount is early;
As a result of the calculation and output of the manipulated variable addition amount with respect to the application of the disturbance, when the decrease width of the control amount with respect to the set value exceeds a second specified value before the increase of the control amount appears, the manipulated variable An eighth step of determining that the output start timing of the addition amount is late;
A ninth step of presenting the determination results of the seventh and eighth steps. A first step of calculating an operation amount by PID control calculation using the set value and the control amount as inputs,
A second step of obtaining a manipulated variable subtraction value that is a target value of a subtraction amount for feedforward with respect to the manipulated variable, which is input from the outside when the disturbance application is determined,
After a first time elapses from the acquisition of the manipulated variable subtraction value different from the zero value, a third manipulated variable subtraction amount that gradually converges to a zero value after approaching the manipulated variable subtraction value is calculated. Steps and
A fourth step of subtracting the operation amount subtraction amount calculated in the third step from the operation amount calculated in the first step to change the operation amount;
A fifth step of performing limit processing for limiting the manipulated variable changed in the fourth step to a value equal to or greater than the manipulated variable lower limit and equal to or less than the manipulated variable upper limit;
A sixth step of outputting the operation amount subjected to the limit processing to a control target;
As a result of the calculation and output of the manipulated variable subtraction amount with respect to the application of the disturbance, if the decrease width of the control amount with respect to the set value exceeds a first specified value before the increase of the control amount appears, the manipulated variable A seventh step of determining that the output start timing of the subtraction amount is early;
As a result of the calculation and output of the manipulated variable subtraction amount with respect to the application of the disturbance, if the increase of the control amount with respect to the set value exceeds a second specified value before the decrease of the control amount appears, the manipulated variable An eighth step of determining that the output start timing of the subtraction amount is late;
A ninth step of presenting the determination results of the seventh and eighth steps.