JP2009230570A - Parameter controller and control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the probability of wasting vertical fluctuations of a manipulated variable. <P>SOLUTION: A parameter controller 1 includes an AT execution part 3 for generating a limit cycle of repeatedly outputting a manipulated variable MV of predetermined amplitude to a controlled object, a vertical fluctuation detection part 4 for detecting responses of a controlled variable PV to the output of the manipulated variable MV, a minimum vertical fluctuation frequency determination part 5 for issuing a parameter calculation start notification when the vertical fluctuation frequency of the controlled variable PV reaches a prescribed minimum vertical fluctuation frequency after the start of auto tuning, and a PID parameter value calculation part 7 for calculating PID parameters and setting them to a PID controller 2 at each time when responses of the controlled variable PV necessary to calculate PID parameters are obtained after the parameter calculation start notification. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a process control technique, and in particular, generates a limit cycle that repeatedly outputs a manipulated variable having a constant amplitude to a controlled object, and a control device such as a PID based on a response of the controlled object according to the output of the manipulated variable The present invention relates to a parameter adjusting apparatus and an adjusting method having an auto-tuning function for adjusting the control parameters of the control.

  In control devices such as temperature controllers, a limit cycle type auto-tuning (hereinafter referred to as AT) function is widely adopted, and PID parameter values for PID control calculation are automatically determined thereby (for example, Patent Documents). 1). This limit cycle type AT is designed to adjust the PID parameter value by setting an upper limit value and a lower limit value in advance for the manipulated variable MV output to the controlled object, generating a limit cycle with a constant manipulated variable amplitude. It is.

JP 2006-106925 A

  In the conventional AT disclosed in Patent Document 1, the AT is terminated by generating a limit cycle in which the operation amount moves up and down a designated number of times. However, in the case of a conventional AT in which the operation amount is moved up and down by the number of times designated in advance, the number of operations of the operation amount may be insufficient in a higher-order control target.

  As a countermeasure for this, a method is also used in which the operator determines the required number of vertical movements and sets it in advance. However, with this method, a case is assumed in which the number of times the operation amount moves up and down increases. If the number of times the operation amount moves up and down increases, a situation in which when the AT is interrupted for some reason, a situation in which it is unavoidable that the AT must be terminated is likely to occur. In the conventional AT, if the process is terminated halfway, it becomes impossible to calculate the PID parameter value, and there is a problem that the vertical movement up to that point is wasted.

  SUMMARY An advantage of some aspects of the invention is to provide a parameter adjustment device and an adjustment method capable of reducing the probability that the up and down movement of the operation amount is wasted.

The present invention generates a limit cycle that repeatedly outputs a manipulated variable having a constant amplitude to a controlled object, and calculates a control parameter of a control device based on the response of the controlled object according to the output of the manipulated variable. In the parameter adjustment device having a function, when the auto-tuning execution means for generating the limit cycle and after starting the auto-tuning, the number of up-and-down movements of the control amount exceeds a predetermined minimum number of up-and-down movements Control unit for calculating the control parameter every time when a response of a control amount necessary for calculating the control parameter is obtained after receiving the parameter calculation start notification Parameter value calculation means for setting in the device.
Further, in one configuration example of the parameter adjusting device of the present invention, after the auto tuning is started, the auto tuning is performed when the number of vertical movements of the control amount exceeds a predetermined number of vertical movement completions. Comparing the number of vertical movement completion times determination means for notifying completion of auto-tuning to be completed, and the latest control parameter calculated by the parameter value calculating means when the auto-tuning completion notification is received and the control parameter calculated immediately before When the ratio between the immediately preceding control parameter and the latest control parameter deviates from the upper and lower limit values defined in advance, the operator is notified that the control response at the time of calculating the control parameter may not be stable. Parameter ratio upper and lower limit determining means.

Further, one configuration example of the parameter adjusting device of the present invention is set in the control device when the ratio between the immediately preceding control parameter and the latest control parameter deviates from a predetermined upper and lower limit value. Parameter value correcting means for correcting the latest control parameter based on the ratio is provided.
Further, in one configuration example of the parameter adjusting device of the present invention, after the auto tuning is started, the auto tuning is performed when the number of vertical movements of the control amount exceeds a predetermined number of vertical movement completions. Calculated at the time when the auto-tuning is interrupted before the end of auto-tuning is completed before the completion of the vertical movement. The ratio of the last control parameter to the latest control parameter is calculated from the latest control parameter and the control parameter calculated immediately before the latest control parameter, and the latest control parameter set in the control device is set to the ratio. Parameter value correcting means for correcting based on this.
Further, in one configuration example of the parameter adjusting apparatus of the present invention, the parameter value correcting means includes means for notifying an operator of a ratio between the immediately preceding control parameter and the latest control parameter.

  Further, the parameter adjustment method of the present invention includes an auto-tuning execution procedure for generating the limit cycle, and when the number of up-and-down movements of the control amount exceeds a predetermined minimum number of up-and-down movements after starting the auto-tuning. After the reception of the parameter calculation start notification, the control parameter is calculated every time a response of the control amount necessary for calculating the control parameter is obtained. And a parameter value calculation procedure to be set in the control device.

  According to the present invention, since the control parameter is calculated and set in the control device after the number of vertical movements of the controlled variable has passed the minimum number of vertical movements, auto-tuning may be terminated halfway for some reason. Even if a unavoidable situation occurs, there is a high probability that a PID parameter close to an ideal value has already been set in the control device. As a result, in the present invention, when auto-tuning is interrupted, it is possible to reduce the probability of wasting time and labor required for the limit cycle until then.

  In the present invention, the operator is notified when the ratio between the immediately preceding control parameter and the latest control parameter deviates from the predetermined upper and lower limit values. It can be recognized that the control response may not be stable, that is, the control parameter set in the control device may not be appropriate.

  In the present invention, when the ratio between the immediately preceding control parameter and the latest control parameter deviates from the upper and lower limit values defined in advance, the latest control parameter set in the control device is corrected based on the ratio. As a result, a control parameter that is considered to be more appropriate than the latest control parameter before correction can be acquired as a result of auto-tuning.

  Further, in the present invention, when auto tuning is interrupted before the number of times of vertical movement of the control amount has passed the number of times of vertical movement completion, the latest control parameter calculated at the time of interruption and the immediately preceding control parameter are calculated. By calculating the ratio between the immediately preceding control parameter and the latest control parameter from the control parameter and correcting the latest control parameter set in the control device based on the ratio, the control response can be stabilized for some reason. Even when auto-tuning is interrupted at an intermediate stage that cannot be expected so much, control parameters that can be obtained when auto-tuning is continued can be acquired as a result of auto-tuning.

  In the present invention, the operator can acquire the correction index used for correcting the control parameter by notifying the operator of the ratio between the immediately preceding control parameter and the latest control parameter.

[Principle of Invention 1]
1 to 3 are diagrams for explaining the principle of the present invention, and are waveform diagrams showing an example of a change in the control amount PV in accordance with the operation amount output at the time of AT execution. 1 to 3, SP is a set value. FIG. 1 shows an example in which the vertical movement width of the control amount PV is stabilized while being amplified according to an operation amount output (not shown) that moves up and down. In the example of FIG. 1, the difference between the control amount PV and the third vertical motion immediately before that becomes small when the control amount PV has passed the fourth vertical motion after starting AT, that is, the control amount PV is stable. It can be confirmed.

  FIG. 2 shows an example in which the vertical movement width of the control amount PV is stabilized while being attenuated. In the example of FIG. 2, the difference between the control amount PV and the third vertical motion immediately before that becomes small when the control amount PV has passed the fourth vertical motion after the AT is started, that is, the control amount PV is stable. It can be confirmed. FIG. 3 shows an example in which the control amount PV immediately stabilizes. In the example of FIG. 3, when the control amount PV has passed the second vertical movement after the AT is started, the difference from the first vertical movement immediately before that becomes small, that is, the control amount PV is stabilized. I can confirm that.

  If the operator previously sets the number of up / down movements required for the operation amount as before, even if the set number of up / down movements has not been completed, the control response will be in an ideal state at the previous stage. Often approaching. The reason for this is that although the vertical movement of the control amount PV is required to stabilize in a higher-order control target, the vertical movement width of the control amount PV is gradually amplified as shown in FIG. However, since the vertical movement width of the control amount PV approaches the stable vertical movement while gradually decreasing as shown in FIG. This is because the vertical movement does not suddenly change to an appropriate vertical movement. Therefore, if the PID parameter value is calculated and stored step by step as an intermediate determination after the minimum number of times of vertical movement of the control amount PV is obtained, when the AT is interrupted, The inventor has focused on reducing the probability that motion is wasted.

  Also, using the fact that the PID parameter value is also stored as an intermediate determination, the latest PID parameter finally obtained after completion of the set number of vertical movements is compared with the PID parameter calculated immediately before It is also effective to determine whether the difference is large or small and notify the operator.

[Principle of Invention 2]
When the AT is interrupted at a stage where the control amount PV cannot be expected to be stable, the latest PID parameter calculated at the time of the interruption is compared with the PID parameter calculated immediately before, and based on the ratio It is more effective if the latest PID parameter value is corrected.

[First Embodiment]
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 4 is a block diagram showing the configuration of the parameter adjustment apparatus according to the first embodiment of the present invention. This embodiment corresponds to Principle 1 of the invention described above.
The parameter adjustment device 1 detects an AT execution unit 3 that generates a limit cycle for repeatedly outputting an operation amount MV having a constant amplitude to a control target, detects a control response according to the output of the operation amount MV, and obtains information on the control response. A vertical motion detection unit 4 to be acquired, and a minimum vertical motion determination unit 5 that performs a parameter calculation start notification when the number of vertical motions of the control amount PV exceeds a predetermined minimum vertical motion after starting AT. In response to the output of the operation amount MV and the up / down movement completion number determination unit 6 that performs AT completion notification when the number of up / down movements of the control amount PV exceeds a predetermined number of up / down movement completions after the AT is started. A PID parameter value calculation unit 7 that calculates a PID parameter based on the response of the control amount PV and sets it in the PID control device 2, and the latest PID parameter immediately before the AT completion notification is received. When the calculated PID parameter is compared, and the ratio of the immediately preceding PID parameter and the latest PID parameter deviates from the predetermined upper and lower limit values, the control response at the time of calculating the PID parameter may not be stable A PID parameter ratio upper / lower limit determination unit 8 for notifying the operator that there is

  FIG. 5 is a diagram showing an example of a temperature control system to which the parameter adjusting device 1 and the PID control device 2 of the present embodiment are applied. In the example of FIG. 5, a heater 112 and a temperature sensor 113 are installed inside the heat treatment furnace 111. The temperature sensor 113 measures the temperature PV of the air heated by the heater 112. The temperature controller 100 calculates the manipulated variable MV so that the temperature PV matches the set value SP. The power adjuster 114 determines power according to the operation amount MV, and supplies the determined power to the heater 112 through the power supply circuit 115. Thus, the temperature controller 100 controls the temperature in the heat treatment furnace 111. The parameter adjustment device 1 and the PID control device 2 are provided inside the temperature controller 100.

Hereinafter, operations of the parameter adjustment device 1 and the PID control device 2 will be described. FIG. 6 is a flowchart showing the operation of the parameter adjusting apparatus 1, and FIG. 7 is a waveform diagram for explaining the limit cycle type AT used in the present embodiment.
The set value SP is set by the operator and input to the parameter adjusting device 1 and the PID control device 2. The control amount PV is detected by a sensor (not shown) and is input to the parameter adjustment device 1 and the PID control device 2.

  For example, when the AT function is activated in accordance with an operator instruction (step S1 in FIG. 6), the AT execution unit 3 generates a limit cycle (step S2). That is, when the control amount PV is larger than the set value SP, the AT execution unit 3 outputs a predetermined operation amount lower limit set value AL to the control target as the operation amount MV, and when the control amount PV is equal to or less than the set value SP. The predetermined operation amount upper limit setting value AU is output as the operation amount MV to the control object, and is repeatedly performed every fixed operation cycle. Thus, a limit cycle in which the amplitude of the manipulated variable MV is constant as shown in FIG. 7 occurs. In the case of the example in FIG. 5, it goes without saying that the output destination of the operation amount MV is the power regulator 114.

Next, the vertical motion detection unit 4 detects a control response according to the output of the operation amount MV, and acquires information on the control response (step S3). In this detection process, the vertical motion detector 4 calculates the deviation Er between the set value SP and the control amount PV as shown in the following equation.
Er = SP-PV (1)

  As shown in FIG. 7, the vertical movement detection unit 4 includes a first maximum deviation absolute value Er1, which is an absolute value of a deviation between the set value SP and the latest extreme value of the control amount PV, the set value SP, and the control amount PV. The second maximum absolute value Er2, which is the absolute value of the deviation from the second new extreme value, and the first maximum deviation absolute value from time t5 when the sign of the deviation is reversed immediately before the first maximum deviation absolute value Er1. The first maximum manipulated variable switching elapsed time Th1, which is the time until the time t6 when the value Er1 was obtained, and the second maximum deviation absolute value from the time t3 when the sign of the deviation was reversed immediately before the second maximum deviation absolute value Er2. A second manipulated variable switching elapsed time Th2, which is the time until time t4 when Er2 is obtained, is obtained.

Then, the vertical movement detection unit 4 calculates information Th related to the vertical movement width Ah and the vertical movement time of the control amount PV by the following expression and notifies the PID parameter value calculation unit 7 of the information Th.
Ah = Er1 + Er2 (2)
Th = Th1 + Th2 (3)
This completes the process of step S3.

  Next, the minimum vertical motion determination unit 5 determines whether the vertical motion minimum number of the control amount PV has elapsed from the AT start time to the current time (step S4). The predetermined minimum number of vertical movements may be one as a possibility. In counting the number of times the control amount PV moves up and down, the state in which the maximum value and the minimum value of the control amount PV appear once is counted as one time. Alternatively, the time from the rise of the control amount PV (when the deviation (SP-PV) changes from positive to negative) to the next rise may be counted as one time. Further, the time from the fall of the control amount PV (when the deviation (SP-PV) changes from negative to positive) to the next fall may be counted as one time. If it is determined that the number of vertical movements of the control amount PV has not reached the minimum number of vertical movements, the process proceeds to step S5.

  The vertical movement completion count determination unit 6 determines whether the vertical movement completion count of the control amount PV has passed a predetermined number of vertical movement completions between the AT start time and the current time (step S5). The predetermined number of vertical movement completions is larger than the minimum number of vertical movements, and is usually about four times. Here, since it is determined in step S4 that the number of vertical movements of the control amount PV has not reached the minimum number of vertical movements, determination NO is also made in step S5. In this way, the processes in steps S2 to S5 are repeatedly executed at regular operation cycles until the number of vertical movements of the control amount PV has passed the minimum number of vertical movements. This operation cycle may normally be the same as the control cycle of the PID control device 2.

When the number of vertical movements of the control amount PV has passed the minimum number of vertical movements (YES in step S4), the minimum vertical movement number determination unit 5 outputs a parameter calculation start notification signal to the PID parameter value calculation unit 7.
Upon receiving the parameter calculation start notification signal, the PID parameter value calculation unit 7 calculates a PID parameter (step S6). The PID parameter value calculation unit 7 receives control response information (information Th regarding the vertical movement width Ah and vertical movement time of the control amount PV) until the reception time of the parameter calculation start notification signal (t7 in FIG. 7). Is obtained from the vertical motion detection unit 4.

The PID parameter value calculation unit 7 calculates the PID parameter as follows using the information acquired from the vertical motion detection unit 4 and the calculation coefficients α, β, and γ predetermined for calculating the PID parameter value (step S6). ).
Pb = αAh (4)
Ti = βTh (5)
Td = γTh (6)

Then, the PID parameter value calculation unit 7 stores the calculated proportional band Pb, integration time Ti, and differentiation time Td and sets them in the PID control device 2.
Until the number of vertical movements of the control amount PV has passed the number of vertical movements, the processes in steps S2 to S4, S6, and S5 are repeatedly executed at regular operation cycles, and the PID parameter of the PID control device 2 is updated to the latest value. Updated from time to time.

Next, when the number of vertical movements of the control amount PV has passed the number of vertical movements completed (YES in step S5), the vertical movement completion number determination unit 6 outputs an AT completion notification signal to the PID parameter value calculation unit 7.
Upon receiving the AT completion notification signal, the PID parameter value calculation unit 7 calculates and stores the PID parameter and sets it in the PID control device 2 (step S7). The process of step S7 is the same as that of step S6.

  Finally, the PID parameter ratio upper / lower limit determination unit 8 compares the latest PID parameter calculated when the PID parameter value calculation unit 7 receives the AT completion notification signal with the PID parameter calculated immediately before ( Step S8). The latest PID parameter and the immediately preceding PID parameter are stored in the PID parameter value calculation unit 7. When the ratio between the immediately preceding PID parameter and the latest PID parameter deviates from the predetermined upper / lower limit value, the control response at the time of calculating the PID parameter is not stable. The operator is notified that there is a possibility (step S9). For this notification, for example, an LED or the like may be turned on, or a message may be displayed on the screen.

When the latest proportional band is Pb _n and the proportional band calculated immediately before is Pb _n−1 , the PID parameter ratio upper and lower limit determination unit 8 performs the determination in step S8 as follows. That is, the PID parameter ratio upper / lower limit determination unit 8 determines that the ratio Pb _n / Pb _n−1 is larger than the predetermined upper limit value RU (Pb _n / Pb _n−1 > RU), or the ratio Pb _n / Pb _{n. When −1} is smaller than the predetermined lower limit value RL (Pb _n / Pb _n−1 <RL), the determination is YES and the operator is notified.

This completes the AT. Details of the AT are disclosed in, for example, Patent Document 1 and Japanese Patent Application Laid-Open No. 2003-330504.
After the AT is completed, the PID control device 2 calculates the operation amount MV based on the set value SP and the control amount PV and outputs it to the control target for each control cycle as in the following equation.
MV = (ζ / Pb) {1+ (1 / Tis) + Tds} (SP−PV) (7)
In Expression (7), s is a Laplace operator, and the constant ζ is 100, for example. As in the case of AT, it goes without saying that the output destination of the manipulated variable MV is the power regulator 114 in the example of FIG.

  As described above, in the present embodiment, since the PID parameter is calculated and set in the PID control device 2 after the minimum number of vertical movements of the control amount PV has elapsed, the AT is set. Even if a situation that must be terminated halfway due to some circumstances occurs, the probability that a PID parameter close to an ideal value has already been set in the PID control device 2 is increased. As a result, in the present embodiment, when the AT is interrupted, it is possible to reduce the probability of wasting time and effort required for the limit cycle until then.

  In the present embodiment, when the ratio between the immediately preceding PID parameter and the latest PID parameter deviates from the predetermined upper and lower limit values, the operator is notified, so the operator can calculate the PID parameter. It can be recognized that the control response at that time may not be stable, that is, the PID parameter set in the PID control device 2 may not be appropriate.

  In the example of step S8 described above, the comparison is performed only for the proportional band Pb. In general, since the proportional band Pb is calculated based on a value related to the vertical movement width of the control amount PV, it can be used as an index for substantially checking the stability of the vertical movement of the control amount PV. In AT, since the vertical movement width of the control amount PV is stable but the vertical movement time is usually not stable, it is sufficient to compare only the proportional band Pb.

However, the most recent integration time Ti _n and the previous integration time Ti _n-1 to compare in the same manner as described above, even if to compare the derivative time Td _n-1 of the immediately preceding and the latest derivative time Td _n I do not care. When using the ratio _{Pb n / Pb n-1,} Ti n / Ti n-1, 2 or more the ratio of Td _n / Td _n-1 comprises two or more ratios is out of all upper and lower limit The case may be determined as YES in step S8, or may be determined as YES when at least one ratio deviates from the upper and lower limit values.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. FIG. 8 is a block diagram showing the configuration of the parameter adjustment apparatus according to the second embodiment of the present invention. The same components as those in FIG. 4 are denoted by the same reference numerals. This embodiment corresponds to Principle 2 of the invention described above.
The parameter adjustment device 1a of the present embodiment includes an AT execution unit 3, a vertical movement detection unit 4, a vertical movement minimum number determination unit 5, a vertical movement completion number determination unit 6, a PID parameter value calculation unit 7, When the AT is interrupted before the number of vertical movements of the control amount PV exceeds the number of vertical movements completed, the latest PID parameter calculated at the time of the interruption and the PID parameter calculated immediately before it are A PID parameter value correction unit 9 that calculates a ratio between the latest PID parameter and the latest PID parameter, and corrects the latest PID parameter based on the ratio.

FIG. 9 is a flowchart showing the operation of the parameter adjusting device 1a. The processing in steps S1 to S7 is the same as that in the first embodiment.
The PID parameter value correction unit 9 calculates the PID parameter value when, for example, the AT is interrupted by an instruction from the operator (YES in step S10 in FIG. 9) before the number of vertical movements of the control amount PV elapses. The latest PID parameter is corrected based on the value stored in the unit 7 (step S11).

The PID parameter value correction unit 9 sets the latest proportional band calculated at the time when the AT is interrupted as Pb _m , the latest integration time as Ti _m , and the latest derivative time as Td _m, and the proportionality calculated immediately before that. Pb _m-1 bands, Ti _m-1 integration time just before, when the immediately preceding derivative time was Td _m-1, the ratio Pb _m with the immediately preceding proportional band Pb _m-1 and the latest proportional band Pb _m / Pb _m-1, just prior to the integration time Ti _m-1 and the latest integration time ratio Ti _m / Ti _m-1 and Ti _m, and just before the derivative time Td _m-1 and the latest derivative time Td _m The ratio Td _m / Td _m-1 is calculated, and the latest PID parameter is corrected as follows using these ratios as correction indices (step S11).
Pb _m ′ = Pb _m (Pb _m / Pb _m−1 ) (8)
_{Ti m '= Ti m (Ti} m / Ti m-1) ··· (9)
Td _m ′ = Td _m (Td _m / Td _m−1 ) (10)

Then, PID parameter value correction section 9, proportional band Pb _m set in the PID control device 2, the integration time Ti _m, the correction value Pb _m of the derivative time Td _m proportional band calculated respectively ', the correction of integration time The value Ti _m ′ is updated to the differential time correction value Td _m ′. In other words, in the examples of Equations (8) to (10), the appropriate PID parameters that should be obtained when the AT is completed to the end are at least once from the latest PID parameters Pb _m , Ti _m , Td _m. The PID parameter is corrected on the assumption that the ratios Pb _m / Pb _m−1 , Ti _m / Ti _m−1 , and Td _m / Td _m−1 have been changed.

As described above, according to the present embodiment, the PID parameter assumed to be obtained when the AT is further continued even if the AT is interrupted in the middle stage where the stability of the control response cannot be expected for a certain reason. Can be obtained as a result of
In this embodiment, the case where the AT is interrupted in the middle is described. However, as described in the first embodiment, the PID parameter value correction unit 9 performs the previous PID parameter and the latest PID. The latest PID parameter may be corrected when the ratio of the parameter deviates from a predetermined upper and lower limit value.

In the case of the present embodiment, the PID parameter value correction unit 9 notifies the operator that the PID parameter has been corrected, and the ratios Pb _m / Pb _m−1 , Ti _m / Ti _m− used for this correction. it is preferable to notify _1, the Td _m / Td _m-1 to the operator.

  The parameter adjustment devices 1 and 1a and the PID control device 2 described in the first and second embodiments are realized by a computer having a CPU, a storage device, and an interface, and a program for controlling these hardware resources. can do. The CPU executes the processing described in the first and second embodiments in accordance with a program stored in the storage device.

  The present invention can be applied to parameter adjustment of a control device such as PID.

It is a wave form diagram which shows the example of the change of the control amount according to the operation amount output at the time of auto tuning execution. It is a wave form diagram which shows the other example of the change of the control amount according to the operation amount output at the time of auto-tuning execution. It is a wave form diagram which shows the other example of the change of the control amount according to the operation amount output at the time of auto-tuning execution. It is a block diagram which shows the structure of the parameter adjustment apparatus which concerns on the 1st Embodiment of this invention. It is a figure which shows one example of the temperature control system to which the parameter adjustment apparatus and PID control apparatus of FIG. 4 are applied. It is a flowchart which shows operation | movement of the parameter adjustment apparatus which concerns on the 1st Embodiment of this invention. It is a wave form diagram for demonstrating the limit cycle type auto tuning used in the 1st Embodiment of this invention. It is a block diagram which shows the structure of the parameter adjustment apparatus which concerns on the 2nd Embodiment of this invention. It is a flowchart which shows operation | movement of the parameter adjustment apparatus which concerns on the 2nd Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1, 1a ... Parameter adjustment apparatus, 2 ... PID control apparatus, 3 ... AT execution part, 4 ... Vertical motion detection part, 5 ... Vertical motion minimum frequency determination part, 6 ... Vertical motion completion frequency determination part, 7 ... PID parameter value Calculation unit, 8... PID parameter ratio upper and lower limit determination unit, 9... PID parameter value correction unit.

Claims (10)

It has a function of auto-tuning that generates a limit cycle that repeatedly outputs a manipulated variable with a constant amplitude to the controlled object and calculates a control parameter of the control device based on the response of the controlled object according to the output of the manipulated variable In the parameter adjustment device,
Auto tuning execution means for generating the limit cycle;
After starting the auto-tuning, the vertical movement minimum number determination means for notifying the start of parameter calculation when the number of vertical movements of the control amount has passed a predetermined minimum number of vertical movements;
After receiving the parameter calculation start notification, a parameter value calculating unit that calculates the control parameter and sets the control parameter every time a control amount response necessary for calculating the control parameter is obtained. Parameter adjustment device. The parameter adjustment device according to claim 1,
Furthermore, after starting the auto tuning, when the number of vertical movements of the control amount has exceeded a predetermined number of vertical movement completions, the vertical movement completion number determination means for performing an auto tuning completion notification for ending the auto tuning. When,
The latest control parameter calculated by the parameter value calculation means when the auto-tuning completion notification is received is compared with the control parameter calculated immediately before, and the ratio between the previous control parameter and the latest control parameter is determined in advance. A parameter ratio upper / lower limit determining means for notifying an operator that there is a possibility that the control response at the time of calculating the control parameter may not be stable when it deviates from the specified upper / lower limit value. apparatus. The parameter adjustment device according to claim 2, wherein
Further, when the ratio between the immediately preceding control parameter and the latest control parameter deviates from a predetermined upper and lower limit value, the parameter value for correcting the latest control parameter set in the control device based on the ratio A parameter adjusting device comprising a correcting means. The parameter adjustment device according to claim 1,
Furthermore, after starting the auto tuning, when the number of vertical movements of the control amount has exceeded a predetermined number of vertical movement completions, the vertical movement completion number determination means for performing an auto tuning completion notification for ending the auto tuning. When,
When the auto-tuning is interrupted before the number of vertical movements of the control amount has passed the number of vertical movement completions, the latest control parameter calculated at the time of the interruption and the control parameter calculated immediately before And a parameter value correcting means for calculating a ratio between the immediately preceding control parameter and the latest control parameter and correcting the latest control parameter set in the control device based on the ratio. Parameter adjustment device. In the parameter adjustment device according to claim 3 or 4,
The parameter value correcting means has means for notifying an operator of a ratio between the immediately preceding control parameter and the latest control parameter. It has a function of auto-tuning that generates a limit cycle that repeatedly outputs a manipulated variable with a constant amplitude to the controlled object and calculates a control parameter of the control device based on the response of the controlled object according to the output of the manipulated variable In the parameter adjustment method,
Auto tuning execution procedure for generating the limit cycle;
After starting the auto-tuning, when the number of times of vertical movement of the control amount has passed a predetermined minimum number of vertical movements, a procedure for determining the minimum number of vertical movements for performing parameter calculation start notification,
A parameter value calculating procedure for calculating the control parameter and setting the control parameter every time a response of a control amount necessary for calculating the control parameter is obtained after receiving the parameter calculation start notification. Parameter adjustment method. The parameter adjustment method according to claim 6, wherein
Further, after starting the auto tuning, when the number of vertical movements of the control amount has exceeded a predetermined number of vertical movement completions, a vertical movement completion number determination procedure for performing an auto tuning completion notification for ending the auto tuning. When,
The latest control parameter calculated in the parameter value calculation procedure when the auto-tuning completion notification is received is compared with the control parameter calculated immediately before, and the ratio between the immediately previous control parameter and the latest control parameter is determined in advance. A parameter ratio upper / lower limit determination procedure for notifying an operator that there is a possibility that the control response at the time of calculating the control parameter may not be stable when it deviates from the specified upper / lower limit value. Method. The parameter adjustment method according to claim 7, wherein
Further, when the ratio between the immediately preceding control parameter and the latest control parameter deviates from a predetermined upper and lower limit value, the parameter value for correcting the latest control parameter set in the control device based on the ratio A parameter adjustment method comprising a correction procedure. The parameter adjustment method according to claim 6, wherein
Further, after starting the auto tuning, when the number of vertical movements of the control amount has exceeded a predetermined number of vertical movement completions, a vertical movement completion number determination procedure for performing an auto tuning completion notification for ending the auto tuning. When,
When the auto-tuning is interrupted before the number of vertical movements of the control amount has passed the number of vertical movement completions, the latest control parameter calculated at the time of the interruption and the control parameter calculated immediately before And a parameter value correction procedure for calculating a ratio between the immediately preceding control parameter and the latest control parameter and correcting the latest control parameter set in the control device based on the ratio. Parameter adjustment method. The parameter adjustment method according to claim 8 or 9, wherein
The parameter value correcting procedure includes a procedure for notifying an operator of a ratio between the immediately preceding control parameter and the latest control parameter.

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