JP2010266967A - Device and program for adjustment of pid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a PID (Proportional Integral Derivate) adjustment device 30 or the like allowing widely spread of an adjustment method or the like of a PID adjuster to on-site engineers, and allowing a significant reduction of adjustment labor and a time. <P>SOLUTION: A transfer function parameter acquisition unit 32 obtains a parameter of a plurality of transfer functions representing a control target 10 based on time series data of an operation amount MV input to the control target 10 and time series data of a control amount PV output from the control target 10 according to the operation amount MV. An adaptability acquisition unit 34 obtains an adaptation rate between an estimation control amount and an actual control amount output by each transfer function having the parameter. An optimal transfer function selection unit 36 selects the transfer function having optimal adaptability based on the adaptation rate. An optimal PID parameter search unit 38 searches for a PID parameter of the PID adjuster 20 such that a predetermined evaluation index is satisfied from results of a disturbance response to disturbance d and a setting value response to a setting value SV with the selected transfer function (11) or the like as a target. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a PID adjusting device for obtaining a PID parameter of a PID adjuster that controls a controlled object in a closed loop.

  PID (Proportional Integral Derivate) control is a fundamental control technology that is said to occupy over 90% in so-called process industries such as petroleum, chemical, steel, paper pulp, and water environment. It is an indispensable control method for practical use. Conventionally, regarding a method for identifying a control object, a method for adjusting a PID regulator that determines a control parameter of the PID regulator based on a transfer function that is a model obtained from the identification method, a program used for adjustment, and a PID regulator A method of performing trial and error by simulation has been proposed (see Patent Document 1). As described in Patent Document 1, the controller simulation unit sets the value of the control parameter (PID parameter) according to the dialogue processing with the worker, and the worker controls the PID parameter when the PID parameter is appropriate. A simulation end instruction was issued to the vessel simulator.

  As described above, when adjusting the PID parameters by trial and error by simulation, the operator needs experience and know-how regarding the controlled object. For this reason, there has been a problem that the method of performing the trial and error by simulation with respect to the adjustment method of the PID controller and the PID adjustment device is difficult to spread widely to engineers in the field. Furthermore, the method of performing trial and error by simulation has a problem that adjustment labor and time are extremely required.

  Therefore, an object of the present invention is to solve the above problems, and it is possible to widely disseminate the adjustment method of the PID adjuster, the PID adjuster and the like to engineers on the site, and the adjustment effort. It is an object of the present invention to provide a PID adjusting device and the like that can significantly reduce the time.

  A PID adjusting device according to the present invention is a PID adjusting device that obtains a PID parameter of a PID adjuster that controls a controlled object in a closed loop, the time series data of the operation amount input to the controlled object recorded in a recording unit, and the PID adjusting device Based on time series data of the controlled variable output from the controlled object according to the manipulated variable, transfer function parameter acquiring means for determining a plurality of transfer function parameters representing the controlled object, and obtained by the transfer function parameter acquiring means A fitness acquisition means for determining the compatibility between the estimated control amount output by each transfer function having the parameters and the actual control amount, and the best compatibility based on the compatibility obtained by the compatibility acquisition means. The best transfer function selection means for selecting or selecting a transfer function is paired with the transfer function selected or selected by the best transfer function selection means. As, characterized in that a optimum PID parameter search means for searching the PID parameters of the PID controller to meet the evaluation index determined in advance from results of the set value response and disturbance response.

  Here, in the PID adjusting device of the present invention, the result of the set value response and the disturbance response used by the optimum PID parameter search means is the result of the set value response and the disturbance response in a state where white noise is injected into the control amount. Can do.

  Here, in the PID adjustment apparatus of the present invention, the evaluation index used by the optimum PID parameter search means can be an index obtained by integrating the square of the difference between the control amount and the step-like set value with time.

  Here, in the PID adjustment apparatus of the present invention, the suitability used by the suitability acquisition unit can be a predetermined suitability ratio based on an estimated control amount, an actual control amount, and an average value of the actual control amounts.

  The PID adjustment program according to the present invention is a PID adjustment program for obtaining a PID parameter of a PID adjuster that controls a controlled object in a closed loop, and is recorded in a recording unit in a computer of the PID adjustment apparatus that executes the PID adjustment control program. A transfer function for obtaining parameters of a plurality of transfer functions expressing the control object based on the time series data of the operation amount input to the control object and the time series data of the control amount output from the control object according to the operation amount A parameter obtaining step, a suitability obtaining step for obtaining suitability between an estimated control amount output by each transfer function having the parameters obtained in the transfer function parameter obtaining step and an actual control amount, and obtained in the suitability obtaining step. The best transfer function that selects or selects the transfer function with the best fit based on the best fit Searching for the PID parameter of the PID controller to satisfy the evaluation index determined in advance from the result of the set value response and the disturbance response for the transfer function selected or selected in the selection step and the best transfer function selection step It is a PID adjustment program for executing the optimal PID parameter search step.

  Here, in the PID adjustment program of the present invention, the result of the set value response and the disturbance response used in the optimum PID parameter search step is the result of the set value response and the disturbance response in a state where white noise is injected into the control amount. Can do.

  According to the PID adjustment device or the like of the present invention, the optimum PID parameter search unit of the PID adjustment device targets the transfer function selected or selected by the best transfer function selection unit, and the set value response and disturbance to the set value SV. The PID parameter of the PID adjuster can be searched so as to satisfy a predetermined evaluation index from the result of the disturbance response to d. As a result, it is not necessary for the operator to determine the PID parameters based on experience and know-how related to the control target, so that the PID controller adjustment method, PID adjustment device, and the like are widely disseminated to on-site engineers. In addition, the adjustment labor and time can be remarkably shortened.

It is a figure which shows the PID adjustment apparatus in Example 1 of this invention. 4 is a diagram illustrating a configuration of a transfer function parameter acquisition unit 32. FIG. It is a figure which shows the state in which the best transfer function selection part 36 selects or makes it select the transfer function which has the best fitness based on fitness FIT (%). 4 is a diagram for explaining a function of an optimum PID parameter search unit 38. FIG. 5 is a time chart of the set value SV, disturbance d, and control amount PV described in FIG. It is a flowchart which shows the flow of a process when each function of the PID adjustment apparatus 30 is implement | achieved by software. It is a figure which shows the PID adjustment apparatus in Example 2 of this invention. It is a figure for demonstrating the function of the optimal PID parameter search part 38 in Example 2. FIG. It is a figure which shows the time chart of setting value SV demonstrated in FIG. 8, disturbance d, and control amount PV. It is a block diagram which shows the internal circuit 40 of the computer in the PID adjustment apparatus 30 which executes the PID adjustment program of this invention.

  Hereinafter, each embodiment will be described in detail with reference to the drawings.

  FIG. 1 shows a PID adjustment apparatus according to Embodiment 1 of the present invention. In FIG. 1, reference numeral 10 denotes a control object, 20 denotes a PID adjuster that controls the control object 10 in a closed loop, and 30 denotes a PID adjustment device that obtains a PID parameter of the PID adjuster 20. As illustrated in FIG. 1, the operation amount MV is input from the PID adjuster 20 to the control target 10, and the control amount PV is output from the control target 10 according to the operation amount MV and the disturbance d. As shown in FIG. 1, the PID adjustment device 30 includes a transfer function parameter acquisition unit (transfer function parameter acquisition unit) 32, a suitability acquisition unit (compatibility acquisition unit) 34, and a best transfer function selection unit (best transfer function selection). Means) 36 and an optimum PID parameter search unit (optimum PID parameter search means) 38. Hereinafter, description will be made with reference to FIG. 1 and other drawings as appropriate.

  As shown in FIG. 1, the transfer function parameter acquisition unit 32 includes time series data (indicated by dotted lines) of the operation amount MV input to the control object 10 recorded in the recording unit (recording device 48 such as a disk to be described later). MV) and the time series data (PV indicated by a dotted line) of the control amount PV output from the control object 10 in accordance with the manipulated variable MV, a plurality of transfer functions representing the control object 10 Find the parameters.

FIG. 2 shows the configuration of the transfer function parameter acquisition unit 32. In FIG. 2, reference numerals 11 to 17 denote a plurality of transfer functions that represent the control object 10 whose structure is previously determined offline. As shown in FIG. 2, the transfer function 11 is a first-order system (or first-order element) + dead time (or time-delay element), the transfer function 12 is a second-order system (or second-order element) + dead time, and a transfer function. 13 is a primary system + integration system (integration element) + dead time, transfer function 14 is a secondary system + integration system, transfer function 15 is a secondary system (vibration system: damping coefficient ζ of the secondary sway element is 0 <ζ < 1 and step response is oscillatory) + dead time, transfer function 16 is integral system + dead time, and transfer function 17 is a non-minimum phase system. As described above, FIG. 2 shows examples of seven types of transfer functions 11 to 17, but other transfer functions may be used as a matter of course. The transfer function parameter acquisition unit 32 is a parameter of each transfer function 11 to 17 from the time series data of the operation amount MV and the time series data of the control amount PV output from the control target 10 according to the operation amount MV. gain constant ^{G *,} the time constant _{^{T *, T 1 *, T}} 2 *, T 3 *, the dead time ^{L *,} attenuation coefficient zeta ^*, obtains the natural angular frequency omega ^*. These parameters of the transfer functions 11 to 17 can be obtained by obtaining the minimum value of the objective function J shown by the following expression 1.

Here, PV ^* is an estimated control amount. Since Equation 1 is an (unconstrained) nonlinear optimization problem, the minimum value J of Equation 1 can be obtained by applying, for example, the Newton method, the quasi-Newton method, the steepest descent method, or the like.

As shown in FIG. 1, the suitability acquisition unit 34 includes an estimated control amount (PV ^* indicated by a dotted line) output by each transfer function having parameters obtained by the transfer function parameter acquisition unit 32 and an actual control amount. The compatibility with the PV indicated by the dotted line is obtained. The k-th estimated control amount obtained by the transfer function parameter acquisition unit 32 is PV ^* (k), the k-th actual control amount is PV (k), and the average value of the control amounts PV (k) is

Then, the conformity can be obtained from the conformity rate FIT (%) expressed by the following formula 2.

Here, N represents the number of data of time series data. In the present specification, the precision FIT (%) is used for comparing two data of the estimated control amount PV ^* and the actual control amount PV. However, it is also possible to use the correlation of two data instead of the precision FIT (%).

  As shown in FIG. 1, the best transfer function selection unit 36 selects a transfer function having the best fitness based on the fitness FIT (%) (FIT indicated by a dotted line) obtained by the fitness acquisition unit 34. Select or have it selected. FIG. 3 shows a state where the best transfer function selection unit 36 selects or selects a transfer function having the best fitness based on the fitness FIT (%). In FIG. 3, the same reference numerals as those in FIG. FIG. 3 shows, in tabular form, the transfer function column, the matching rate column, the selection column, and the transfer functions 11 to 17. The state to be selected or selected can be displayed on the display device 44 such as a display described later in the table format. As shown in FIG. 3, the best transfer function selection unit 36 displays the relevance ratio FIT (%) calculated for each transfer function 11 and the like in the relevance ratio column corresponding to each transfer function field, A transfer function with a good FIT (%) is selected by displaying a check or the like in the selection column. In FIG. 3, a state in which the transfer function 11 is selected is displayed. The selection is automatically selected by the best transfer function selection unit 36 based on the value of the precision FIT (%), but any transfer function 11 or the like can be manually selected. In this case, selection can be made by clicking a desired rectangle in the selection column using an input operation unit 51 such as a mouse described later.

  As shown in FIG. 1, the optimum PID parameter search unit 38 sets a set value (described later) for the transfer function 11 or the like (11 indicated by a dotted line) selected or selected by the best transfer function selection unit 36. The PID parameter of the PID adjuster 20 is searched so as to satisfy a predetermined evaluation index from the result of the set value response to SV) and the disturbance response result to disturbance (d described later).

FIG. 4 is a diagram for explaining the function of the optimum PID parameter search unit 38. In FIG. 4, portions denoted by the same reference numerals as those in FIG. As shown in FIG. 4, first, a step-like signal is input to the set value SV, and after the step response has converged, a signal on the step is input to the disturbance d, and the evaluation index is calculated from the control amount PV as the output. calculate. FIG. 5 shows a time chart of the set value SV, the disturbance d, and the control amount PV described in FIG. 5A is the set value SV, FIG. 5B is the disturbance d, FIG. 5C is the control amount PV, the horizontal axis is time, and the time t _d is the addition of the disturbance d to the manipulated variable MV. Time given. In the calculation of the evaluation index shown in FIG. 4, the evaluation index is calculated using ISE (Integral of Squared Error) expressed by the following Expression 3.

Here, e (t) = PV-SV. That is, the evaluation index is an index obtained by integrating the square of the difference between the control amount PV and the step-like set value SV from 0 to infinity over time. FIG. 5 shows a rise time portion of the control amount PV and a portion to which a disturbance response is added for e (t). Equation 3, which is an evaluation index, is, for example, a proportional gain K _P , integration time T _i , differentiation, which is a parameter of the PID controller 20 by a search method such as Particle Swarm Optimization (PSO). You can determine the time _{T D.}

  PSO is one of the modern heuristic (MH) methods developed through the simulation of a simplified social model, and was developed through expressing the movement of a flock of birds in a two-dimensional space of continuous variables. .

  Regarding PSO, “Partic1e Swarm Optimization” by J. Kennedy and R. Eberhart (Proc. Of IEEE International Conference on Neural Networks, Vol. IV, pp.1942-1948, Perth, Australia, 1995.), Yoshida, Fukuyama, etc. "Study of Voltage Reactive Power Control Method by Particle Swarm Optimization Considering Voltage Reliability" (The Institute of Electrical Engineers of Japan B, Vol.119, No.12, December 1999), JP 2000-11603 "Voltage Reactive Power Control Method" JP 2002-51464 “State estimation method in distribution system” and the like.

  In PSO, the position (state quantity) of each agent (in PSO, each group is called an agent) is represented by x and y coordinates, and the velocity of each agent is represented by vx (velocity in x direction) and vy (in y direction). (Speed). From the position and speed information of each agent, the position of each agent at the next time point can be updated.

  Based on the above-mentioned agent concept, the following optimization can be considered if the whole flock of birds takes an action that optimizes some objective function. That is, each agent remembers the best value pbest with the highest evaluation before the objective function in each search and the x and y coordinates indicating the position (state quantity) at that time. Each agent shares the highest value among the group of best values pbest held by each agent, that is, the best value gbest of the previous objective function of the group. Each agent has a current position (x, y coordinates) and a current velocity (vx, vy). Each agent moves to the position where the best values pbest and gbest exist according to the distance between the current position (x and y coordinates) and velocity (vx and vy) and the best values pbest and gbest. Try to change.

  The action to be changed is expressed by speed. The speed of each agent can be corrected as shown in Equation 4 using the current speed and the best values pbest and gbest.

V _i ^{k + 1} = w × V _i ^k + c ₁ × rand () × (pbest _i −s _i ^k )
+ C ₂ × rand () × (gbest _i −s _i ^k ) (4)

Where V _i ^k is the speed of agent i, rand () is a uniform random number from 0 to 1, s _i k is the position (search point) of agent i in search k, and pbest _i is agent i best value pbest, w is the weighting function for the agent velocity, c _1, c ₂ are weighting coefficients for each term.

By using the above equation 4, it is possible to obtain a speed V _i ^{k + 1} that probabilistically approaches the previous best value pbest _i of each agent i and the best value gbest of the group, and each agent i is determined by the speed V _i ^{k + 1.} The current position (search point) s _i ^k can be corrected as shown in Equation 5.

s _i ^{k + 1} = s _i ^k + V _i ^{k + 1} (5)

In practice, the state variables of the PSO agent are the proportional gain K _P , the integration time T _i , and the differentiation time T _D which are PID parameters.

Next, the agent position s _i and the velocity v _i are set as initial values of the agent. Note that the number i of agents is set in advance.

Subsequently, the optimum solution is searched by repeating the calculations of Equations 4 and 5. Here, the number of repetitions k is set in advance. When searching for the optimum solution, the evaluation of each agent _i and the update of the best value pbest _i of each search point and the best value gbest of the group are performed at each step of the iteration.

Here, the evaluation of each agent i can be performed by the following procedure. First, the state variable _{s i} of agent i, proportional gain _{K P} is a PID parameter, integral time _{T i,} set the derivative time _{T D,} then the disturbance response to setpoint response and the disturbance d for the set value SV From the result, the evaluation index (Formula 3) is evaluated. Based on the evaluation results of all agents, the best value pbest _i of each search point and the best value gbest of the group are determined. After the designated number of repetitions k has ended, the optimal PID parameter is obtained by setting the state quantity of the best value gbest of the group as a proportional gain K _P , integration time T _i , and differentiation time T _D as PID parameters. As described above, the optimum PID parameter of the PID controller 20 can be obtained.

  Each function of the transfer function parameter acquisition unit 32 and the like of the PID adjustment device 30 shown in FIG. 1 can be realized by using software or hardware partly or entirely. FIG. 6 is a flowchart showing the flow of processing when all the functions of the PID adjustment apparatus 30 are realized by software. A case where the software or hardware is partially or wholly implemented can be described by the same flowchart.

As shown in FIG. 6, the PID adjustment program for obtaining the PID parameter of the PID adjuster 20 that controls the control target 10 in a closed loop is stored in a computer (CPU 41 described later) of the PID adjustment apparatus that executes the PID adjustment control program. The following steps are executed. First, the time series data of the operation amount MV input to the control object 10 recorded in the recording unit (recording device 48 or the like described later) and the time series data of the control amount PV output from the control object 10 according to the operation amount MV. Based on the above, parameters such as a plurality of transfer functions 11 expressing the control object 10 are obtained (transfer function parameter acquisition step, step S10). Next, the suitability (fitness rate FIT (%)) between the estimated control amount PV ^* output by each transfer function 11 having the parameters obtained in the transfer function parameter acquisition step (step S10) and the actual control amount PV. (Adaptability acquisition step. Step S12). Subsequently, based on the suitability obtained in the suitability acquisition step (step S12), the transfer function having the best suitability is selected or selected (best transfer function selection step; step S14). Finally, with respect to the transfer function selected or selected in the best transfer function selection step (step S14), an evaluation index (formula) determined in advance from the result of the set response to the set value SV and the disturbance response to the disturbance d The PID parameter of the PID adjuster 20 is searched so as to satisfy 3) (optimum PID parameter searching step, step S16).

As described above, according to the first embodiment of the present invention, the PID adjustment device 30 has the functions of the transfer function parameter acquisition unit 32, the suitability acquisition unit 34, the best transfer function selection unit 36, and the optimum PID parameter search unit 38. is doing. The transfer function parameter acquisition unit 32 is output from the control target 10 according to the time series data of the operation amount MV input to the control target 10 recorded in the recording unit (a recording device 48 described later) and the operation amount MV. Based on the time series data of the controlled variable PV, parameters of a plurality of transfer functions (gain constant G ^* , time constant T ^* , T ₁ ^* , T ₂ ^* , T ₃ ^* , dead time L ^* representing the controlled object 10 are represented ^. , Attenuation coefficient ζ ^* , natural angular frequency ω ^* ). It is preferable to use a plurality of transfer functions (for example, the seven transfer functions 11 shown in FIG. 2) representing the control object 10 whose structure has been previously determined offline. It is not limited to. The parameters of the transfer functions 11 to 17 can be obtained by obtaining the minimum value of the objective function J expressed by the equation 1. The conformity acquisition unit 34 outputs the estimated control amount (PV ^* indicated by the dotted line) output by each transfer function having the parameter obtained by the transfer function parameter acquisition unit 32 and the actual control amount (PV indicated by the dotted line). ). The suitability can be obtained from the fit rate FIT (%) expressed by Equation 2. It is also possible to use the correlation of two data instead of the precision FIT (%). The best transfer function selection unit 36 selects or selects a transfer function having the best fitness based on the fitness FIT (%) obtained by the fitness acquisition unit 34. The selection or selection state can be displayed on a display device 44 such as a display described later. The selection is automatically selected by the best transfer function selection unit 36 based on the value of the precision FIT (%), but any transfer function 11 or the like can be manually selected. The optimum PID parameter search unit 38 is determined in advance from the result of the set value response to the set value SV and the disturbance response to the disturbance d for the transfer function 11 or the like selected or selected by the best transfer function selection unit 36. The PID parameter of the PID controller 20 is searched so as to satisfy the evaluation index. The calculation of the evaluation index can be performed using the ISE represented by Expression 3. Equation 3, which is an evaluation index, can determine, for example, the proportional gain K _P , integration time T _i , and differentiation time T _D that are parameters of the PID adjuster 20 by search means having a search method such as PSO.

  As described above, according to the first embodiment of the present invention, the optimum PID parameter searching unit 38 of the PID adjusting device 30 sets the transfer function 11 or the like selected or selected by the best transfer function selecting unit 36 as a target. The PID parameter of the PID adjuster 20 can be searched so as to satisfy a predetermined evaluation index from the results of the set value response to the value SV and the disturbance response to the disturbance d. As a result, it is not necessary for the operator to determine the PID parameters based on experience and know-how related to the controlled object 10, so that the method for adjusting the PID adjuster, the PID adjuster, etc. are widely used by engineers on site. In addition, the adjustment labor and time can be significantly reduced.

  FIG. 7 shows a PID adjustment apparatus according to Embodiment 2 of the present invention. In FIG. 7, the same reference numerals as those in FIG. The difference between the second embodiment and the first embodiment is that, as shown in FIG. 7, white noise w (different from the weighting function of Equation 4 above) is injected into the control amount PV. .

FIG. 8 is a diagram for explaining the function of the optimum PID parameter search unit 38 in the second embodiment. In FIG. 8, the same reference numerals as those in FIG. As shown in FIG. 8, in a state where white noise w is injected into the control amount PV, a step-like signal is first input to the set value SV, and after the step response has converged, the signal on the step is applied to the disturbance d. The evaluation index is calculated from the control amount PV that is input and output. FIG. 9 is a time chart of the set value SV, the disturbance d, and the control amount PV described in FIG. 9A is the set value SV, FIG. 9B is the disturbance d, FIG. 9C is the control amount PV, the horizontal axis is time, and the time td is the disturbance d added to the manipulated variable MV. (+) Time. As shown in FIG. 9C, it can be seen that the white noise w is injected into the control amount PV. By injecting the white noise w into the control amount PV, it is possible to prevent a high gain of the PID parameter (a phenomenon in which the gain of the optimal PID parameter increases). As described above, in the second embodiment, the white noise w is injected into the control amount PV as the result of the set value response to the set value SV and the disturbance response to the disturbance d used by the optimum PID parameter search unit 38 of the PID adjusting device 30. It is a result of a set value response of a state and a disturbance response. The optimum PID parameter search unit 38 searches for the parameters of the PID adjuster 20 so as to satisfy a predetermined evaluation index from the result of the set value response and the disturbance response in the state where the white noise w is injected into the control amount PV. To do. In the calculation of the evaluation index shown in FIG. 8, the evaluation index is calculated using the ISE represented by Expression 3, as in the first embodiment. In FIG. 9, as in the first embodiment, the rise time portion of the control amount PV and the portion to which the disturbance response is added are shown for e (t). As in the first embodiment, Expression 3, which is an evaluation index, can determine the proportional gain K _P , integration time T _i , and differentiation time T _D that are parameters of the PID controller 20 by a search method such as PSO. .

  Since the other functions of the PID adjusting device 30 in the second embodiment are the same as those in the first embodiment, description thereof is omitted. Each function of the PID adjustment device 30 can be realized by using a part or all of software or hardware as in the first embodiment. Regarding the function of the PID adjustment program, the result of the set value response and the disturbance response used in the optimum PID parameter search step (step S16) is the result of the set value response and the disturbance response in the state where the white noise w is injected into the control amount PV. Since it is the same as that of Example 1 except for a certain point, description is abbreviate | omitted.

  As described above, according to the second embodiment of the present invention, in the state where the white noise w is injected into the control amount PV, a step-like signal is first input to the set value SV, and after the step response has converged, the disturbance d A signal on the step is input, and an evaluation index is calculated from the control amount PV that is an output. The optimum PID parameter search unit 38 searches for the parameters of the PID adjuster 20 so as to satisfy a predetermined evaluation index from the result of the set value response and the disturbance response in the state where the white noise w is injected into the control amount PV. To do. As described above, in addition to the effect of the first embodiment, by injecting the white noise w into the control amount PV, it is possible to prevent the high gain of the PID parameter (a phenomenon in which the gain of the optimal PID parameter is increased). be able to.

  As described above, the PID adjustment apparatus 30 of the present invention can be realized entirely as hardware, or part or all can be realized as software. FIG. 10 is a block diagram showing an internal circuit 40 of a computer in the PID adjustment apparatus 30 that executes the PID adjustment program of the present invention. As shown in FIG. 10, the CPU 41, ROM 42, RAM 43, image control unit 46, controller 47, input control unit 50, and external I / F unit 52 are connected to a bus 53. In FIG. 10, the above-described PID adjustment program of the present invention is recorded on a recording medium (including a removable recording medium) such as a ROM 42, a disk 48, a DVD or a CD-ROM 49. On the disk 48 (recording unit), the time series data file 61 of the operation amount MV used by the transfer function parameter acquisition unit 32, the time series data file 62 of the control amount, and the like can be recorded. These time series data files 61 and the like may be recorded on a recording medium 49 such as a DVD or a CD-ROM 49. The parameters of a plurality of transfer functions obtained by the transfer function parameter acquisition unit 32, the relevance ratio FIT (%) obtained by the suitability acquisition unit 34, the transfer function selected or selected by the best transfer function selection unit 36, etc. are temporary. Can be recorded in the RAM 43. The PID adjustment program is loaded into the RAM 43 from the ROM 42 via the bus 53 or from a recording medium such as the disk 48 or DVD or CD-ROM 49 via the controller 47 via the bus 53. The image control unit 46 indicates a state in which desired image data, for example, the best transfer function selection unit 36 shown in FIG. 3 selects or selects a transfer function having the best fitness based on the fitness FIT (%). The image data is sent to the VRAM 45. A display device 44 such as a display displays the image data sent from the VRAM 45. The VRAM 45 is an image memory having a capacity corresponding to the data capacity of one screen of the display device 44. The input operation unit 51 is an input device such as a mouse or a numeric keypad for inputting to the computer. The input control unit 50 is connected to the input operation unit 51 and performs input control. The external I / F unit 52 has an interface function when connecting to the outside of the computer.

  As described above, the CPU 41 executes the PID adjustment program of the present invention, whereby the object of the present invention can be achieved. As described above, the PID adjustment program can be supplied to the computer CPU 41 in the form of a recording medium such as a DVD or a CD-ROM 49, and a recording medium such as a DVD or a CD-ROM 49 on which the PID adjustment program is recorded similarly applies the present invention. Will be composed. As a recording medium on which the PID adjustment program is recorded, for example, a memory card, a memory stick, an optical disc, an FD, or the like can be used in addition to the recording medium described above.

  As an application example of the present invention, it can be applied to a PID control system in a so-called process industry such as petroleum, chemical, steel, paper pulp, and water environment.

  10 control object 11, 12, 13, 14, 15, 16, 17 transfer function, 20 PID adjuster, 30 PID adjustment device, 32 transfer function parameter acquisition unit, 34 compatibility acquisition unit, 36 best transfer function selection unit, 38 Optimal PID parameter search unit, 40 internal circuit, 41 CPU, 42 ROM, 43 RAM, 44 display device, 45 VRAM, 46 image control unit, 47 controller, 49 DVD, CD-ROM, 50 input control unit, 51 input operation Part, 52 external I / F part, 53 bus, 61 time series data file of manipulated variable MV, 62 time series data file of controlled variable.

JP 2004-38428 A

Claims (6)

A PID adjusting device for obtaining a PID parameter of a PID adjuster that controls a control target in a closed loop,
Based on the time-series data of the operation amount input to the control object recorded in the recording unit and the time-series data of the control amount output from the control object according to the operation amount, a plurality of transfer functions representing the control object A transfer function parameter obtaining means for obtaining a parameter;
Suitability obtaining means for obtaining suitability between the estimated control amount output by each transfer function having the parameter obtained by the transfer function parameter obtaining means and the actual control amount;
A best transfer function selecting means for selecting or selecting a transfer function having the best suitability based on the suitability obtained by the suitability obtaining means;
Optimal PID for searching for a PID parameter of a PID controller so as to satisfy a predetermined evaluation index from results of set value response and disturbance response for the transfer function selected or selected by the best transfer function selection means A PID adjusting device comprising a parameter search means.   The PID adjustment apparatus according to claim 1, wherein the result of the set value response and the disturbance response used by the optimum PID parameter search means is a result of the set value response and the disturbance response in a state where white noise is injected into the control amount. A characteristic PID adjusting device.   3. The PID adjustment apparatus according to claim 1, wherein the evaluation index used by the optimum PID parameter search means is an index obtained by integrating the square of the difference between the control amount and the step-like set value with time. PID adjustment device.   4. The PID adjustment apparatus according to claim 1, wherein the compatibility used by the compatibility acquisition unit is a predetermined adaptation rate based on an estimated control amount, an actual control amount, and an average value of the actual control amount. There is a PID adjusting device. A PID adjustment program for obtaining a PID parameter of a PID adjuster that controls a controlled object in a closed loop, the computer of the PID adjustment device that executes the PID adjustment control program,
Based on the time-series data of the operation amount input to the control object recorded in the recording unit and the time-series data of the control amount output from the control object according to the operation amount, a plurality of transfer functions representing the control object A transfer function parameter obtaining step for obtaining a parameter;
A suitability obtaining step for obtaining suitability between the estimated control amount output by each transfer function having the parameters obtained in the transfer function parameter obtaining step and the actual control amount;
A best transfer function selecting step for selecting or selecting a transfer function having the best suitability based on the suitability obtained in the suitability obtaining step;
Optimum PID for searching the PID parameter of the PID controller to satisfy the evaluation index determined in advance from the set value response and disturbance response results for the transfer function selected or selected in the best transfer function selection step A PID adjustment program for executing a parameter search step.   6. The PID adjustment program according to claim 5, wherein the result of the set value response and the disturbance response used in the optimum PID parameter search step is a result of the set value response and the disturbance response in a state where white noise is injected into the control amount. A featured PID adjustment program.

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