JPH03268102A - Automatic tuning controller - Google Patents

Abstract

PURPOSE:To enable an operator to easily set control parameter initial values of the automatic tuning controller by initializing the control parameters by inputting parameter estimated values of a controlled system. CONSTITUTION:When automatic tuning is started, the initial values of the PID parameters of a PID compensator 3 are required. The knowledge of the control is needed to understand the meaning of the initial values and it is difficult to select proper values. For the purpose, the operator inputs rough estimated values of the parameters of the controlled system 1 from the controlled system parameter estimated value input part 11, and a PID initial value calculation part 13 calculates the initial values. Consequently, a proper method can be selected according the start at the start of the automatic tuning, the ability and preference of the operator, etc., and the controller 2 which is easy to use is realized.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention is an auto-tuning system that automatically adjusts various control objects with different characteristics or control objects whose characteristics change to achieve good control. Controller 1: This relates to the controller.

[Prior Art] Figure 5 shows, for example, "Self-Tuning Controller" by Mori and Morita (Computer Roll, 1988 No.
22, pp. 117-125)
1 is a block diagram showing a tuning controller; in the figure, 1 is a controlled object, and 2 is an auto-tuning controller that controls the controlled object 1. FIG. In the auto-tuning controller 2, 3 sets the controlled object I to PTD.
PID compensator 4 for closed-loop control by calculation; PTD compensator 3 according to the error between the output of the controlled object I and the command value;
5 is the auto-tuning section 4, which changes the PID parameters described later to appropriate values.
6 is the PID'gJ initial value input section for inputting the PID parameter initial value used at the start of auto-tuning, 7 is the initial value of the PID parameter determined by roughly identifying the characteristics of the controlled object 1. 8 is the identification signal that the PID initial value design unit 7 adds to the controlled object 1; 9 is the PI
P■D initial value input section 6 for determining the initial value of the D parameter
A switching unit 10 determines which of the PID initial value input unit 6 and the PID initial value design unit 7 is used, and 10 is the PrD parameter initial value determined by the PID initial value input unit 6 or the PID initial value design unit 7.

Next, the operation will be explained.

The PID compensator 3 controls the controlled object 1 by performing a PID/N calculation expressed by the following transfer function C(s) according to the error between the command value and the output of the controlled object 1.

Also, S Nira plus operators Kp, Tr, Kd: PID parameter KP: Proportional gain T1: Integral time constant 4: Differential gain The auto-tuning section 4 takes in the signal of the closed loop system,
Proportional gain Kp, integral constant 'F0. The amount of change ΔI (4, Δ1 to 1Δ) of 4 is determined for the differential gain.

Then, K, ←KP+ΔKFT, +−T, +ΔT,
, K, ←, +Δ, and so on, P
Find the ID parameter change amount 5 and apply it to the PID compensator 3.
Auto tuning controller 2 by giving
The control target 1 can now be controlled well.

When starting auto-tuning, this auto-tuning controller 2 uses PID parameters KP, T
The initial value of r, , K,, ,T,o,.

need to be determined. The PID initial value manual section 6 is for the operator to input KPO1T Ha I Kd6. In addition, the PID initial value design unit 7 adds an identification signal 8 for identification to the controlled object 1, determines the characteristics of the controlled object 1 from the input and output of the controlled object 1 according to this, and initializes PID parameters suitable for this. To the value. ,T,o,to. Determine. The operator can select the PID parameter initial value 10 to be given to the PID compensator 3 by switching the switching unit 9 to use the PID initial value manual unit or the PID initial value design unit 7 depending on the situation.

4= [Problem to be solved by the invention] Since the conventional O-I tuning controller 2 is configured as described above, the initial value of the PID parameter is 10.
When using the PID initial value input section 6 for setting, it is necessary for the operator to have knowledge of the PID parameter initial values within a range that does not cause the control system to become unstable. When used, there were problems such as having to apply a signal to the controlled object 1 to operate it in order to know the characteristics of the controlled object 1.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to obtain an auto-tuning controller in which initial values of control parameters can be easily set.

[Means to solve the problem]

In the auto-tuning controller of the present invention, an operator inputs estimated parameter values of a controlled object, and based on the input parameter estimated values, initial values of control parameters of a control unit that controls the controlled object are calculated. It is something.

[Operation] In the auto-tuning controller 1-roller of the present invention, initial values of control parameters are automatically determined from rough parameter estimates of the controlled object input by the operator.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, parts corresponding to those in FIG. 5 are denoted by the same reference numerals, and explanations thereof will be omitted.

11 is a controlled object parameter estimated value input unit for inputting the parameter estimated value of the model of controlled object 1; 12 is a parameter estimated value inputted from the controlled object parameter estimated value input unit 11; and 13 is a PID from the parameter estimated value 12. In this embodiment, a PID initial value calculation section 13 is used as a control parameter initial value calculation section for calculating initial parameter values.

Reference numeral 14 denotes the control parameter initial value calculated by the PTD initial value calculating section 13, which is the PID parameter initial value given to the PID compensator 3 in this embodiment.

Note that the autotuning unit 4 and the PID compensator 3 constitute a control unit that performs closed-loop control of the controlled object 1.

Next, the operation will be explained.

In FIG. 1, the PID compensator 3, autotuning section 4, PID parameter change amount 5, etc. perform exactly the same operations as those shown in FIG. 5 of the conventional example. The controlled object 1 is a general blunt, such as a temperature control system or a flow rate control system, and has a first-order lag of the following equation - dead time transfer function P (s)
Assume that it can be modeled as

However, K nibrant gain T knee delay time constant ■,: dead time, T, L: parameters of controlled object 1 Figure 2 calculates the specific value of T■7 for the parameters of controlled object 1 above. This is an example response. When a step input of magnitude "1" is applied to controlled object 1, ■( is the final amount of change in the output response, L is the time from when the input is applied until the output starts to change, T is the time required for the output to change by approximately 0.63 K. These values, T and L, are values that are easy to understand intuitively, so the operator can roughly determine the characteristics of the controlled object 1. In many cases, the value is known empirically.

When starting auto-tuning, the PID parameters of the FID compensator 3 are set to the initial values KPo, T.
, o, Kdo are required. However, as mentioned above,
to these initial values. + T + o + Ka.

Understanding the meaning of the value of requires knowledge of the control,
It is difficult for inexperienced workers to select appropriate values. In this invention, from the control target parameter estimated value input unit 11,
Rough estimated values Ko, To, and L of T and L are included in the parameters of the control object 1 described above.

The operator inputs K, and the PID initial value calculation unit 13 inputs K. , To, from T-8.

We are trying to calculate,o,in,T,o,.

The PID initial value calculation unit 13 uses a partial model matching method (Kitamori, ``Control system design method based on partial knowledge of the subject'', Proceedings of the Society of Instrument and Control Engineers).

(1979), 1.5-4. (pages 545-555), the parameter estimate K of the above system 4ffl object 1. , T
, , Lo to the above PID parameter initial value K ro
Find 1T10 +Kdo. That is, o 3-20a lty ” (-100a z ty
-200a 3=O-...The minimum positive real root σ of (4). It can be calculated as follows.

FIG. 3 shows another embodiment of the present invention, in which the conventional PID initial value manual section 6 of FIG.
D. An initial value design section 7 and a switching section 9 are added.

According to the above configuration, as a method for setting the PID parameter initial value 10, in addition to the two conventional methods described above, the first method is used.
Since the method shown in the figure is also provided, an appropriate method can be selected depending on the situation at the start of auto-tuning, the operator's ability, preference, etc., making it an easy-to-use auto-tuning controller.

In each of the above embodiments, the PID initial value calculation unit 13 uses a calculation method based on a partial model matching method, but the parameter estimate K of the controlled object 1 is calculated in advance by many combinations, for example, by simulation. , T. , I, , respectively appropriate PID parameter initial values KPO
, the value of Too + Kao is calculated and made into a table, and the input control object 1 is determined by referring to the table.
A PID that can provide good control over the model of the parameter estimates of
By using a method that allows initial parameter values to be obtained,
” D0 The same effect as in the reporter embodiment is produced.

In addition, in each of the above embodiments, −
As described above, the system of the next lag timer dead time can be created by modifying the PTD initial value calculation section 13 and the controlled object parameter estimated value input section 11, if it is suitable as a model for the controlled object 1. realizable.

FIG. 4 shows an embodiment in which the auto-tuning controller 2 according to the present invention is applied to a motor/mechanical system.

In FIG. 4, 1 is a motor/mechanical system to be controlled, and its internal calculation units 1a lb lc ld
, L12 is the motor winding inductance, R is the motor winding resistance, KT is the motor torque constant, K is the motor induced voltage constant, and ■ is the inertia including the motor torque and the mechanical system. Further, 3 is a compensator for controlling the motor/mechanical system, and in its internal calculation units 3a, 3b, and 3C, Gc is a current gain, GV is a speed gain, G8 is a speed integration time constant, and GP is a position gain. It is. In addition, in the figure, TT2 and T3 T, which are shown in the form of switches, respectively indicate sampling times. The auto-tuning unit 4 changes the values of the control parameters GcGv Gi, G to appropriate values based on the control signal, as in the embodiment described above.

In this embodiment, the control parameters Gc, Gv.

Initial values of Gt, Gp G Co, cvo, G, O
, GPO, the parameter estimated values I7RKc, Kt, I of the controlled object 1 are inputted from the controlled object parameter estimated value input section 11. Above, R, KC
,K.

is a constant of the motor, and can be easily known once the motor is determined. Also, ■ is the inertia of the mortar clock and the mechanical system, and the approximate value can usually be determined. G.
,. , C, vo, G, . . . In the control parameter initial value calculation unit 13 that calculates Gco, the control parameter initial values can be set by a method such as preparing a table in advance using the simulator described in the above embodiment. Autochi J for motors and mechanical systems.

The present invention is effective in the controlling controller 2 because it is easy to obtain the parameter values of the controlled object 1.

1 [Effects of the Invention] As described above, according to the present invention, since the automatic tuning controller 1 is configured such that the initial value of the control parameter of the roller can be set by inputting the estimated parameter value of the controlled object, the operator can start the control. This makes it easier to set the initial values of control parameters prior to the process, and allows for accurate initial value settings, resulting in a short tuning time.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an O1 to tuning controller according to an embodiment of the present invention, FIG. 2 is a characteristic diagram showing an example of time response of plant parameters, and FIG. FIG. 4 is a block diagram showing an autotuning controller according to still another embodiment of the present invention,
FIG. 5 is a block diagram showing a conventional auto-tuning controller. 1 is a controlled object, 2 is an auto-tuning controller [7-ra], 3 is a PID compensator, 4 is an auto-tuning section, 11 is a controlled object parameter estimated value input section, 13
is the PID initial value calculation section. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] The auto-tuning controller has a control section that performs closed-loop control of the controlled object based on the output of the controlled object and a command value, and the control section starts the control based on the initial value of the control parameter. A controlled object parameter estimated value input section for inputting the parameter estimated value of the controlled object, and a control parameter initial value calculation section for calculating the control parameter initial value based on the inputted controlled object parameter estimated value. An auto tuning controller featuring