JP2844636B2 - Program control unit - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a program control device that causes a control amount of a localization control target to follow a given target value pattern.

<< Summary of the Invention >> In the present invention, a correction unit for correcting a given target value pattern based on a control parameter of a control device and a steady gain of a localization target is provided, and the localization target is corrected with respect to the correction unit. By providing the steady-state gain measuring section that outputs the steady-state gain, the control amount can always follow the true ramp-shaped target value, and the steady-state deviation amount and the overshoot amount (overshoot amount) can be reduced.

<< Prior Art and its Problems >> Conventionally, as a program device for causing a control amount to follow a predetermined target value pattern, the one shown in FIG. 9 is known.

That is, the conventional program control device is roughly composed of a control target 1 of a localization system, a PID control device 2, a target value feedforward unit 3 of a two-degree-of-freedom PID control device, and a steady gain output unit 4 of the control device. .

FIGS. 10 and 11 show the results when the program control is executed by this conventional program control device.
FIG.

FIG. 10 is a control result when the control amount y is set by the PID control device 2 and the steady gain output unit 4 of the control device in FIG. 9, where r (t) is a target value.

FIG. 11 shows a PID control device 2 in which the control amount y is shown in FIG.
Value feed-forward section of PID controller with two degrees of freedom
3, PID with full configuration of steady-state gain output unit 4 of control device
It is a control result in the control device.

The evaluation items of control performance in these two program control devices are often grouped into the following two items.

That is, both the steady-state deviation amount in the section where the target value changes in a ramp shape and the overshoot amount (overshoot amount) when the target value changes from the ramp shape to a constant value are set to small values. Is required, and the performance is judged as good or bad.

However, in the case of FIG. 10, the steady-state deviation amount is small, but the overshoot amount is large. Conversely, in the case of FIG. 11, the overshoot amount is small, but the steady-state deviation amount is large.

That is, in the above two examples, there is a trade-off relationship between the two, and there is a problem that both cannot be satisfied simultaneously.

<< Object of the Invention >> The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a program control device in which a steady-state deviation amount and an overshoot amount are suppressed as small as possible to improve control performance. Is to provide.

<< Structure and Effect of the Invention >> In order to achieve the above object, the present invention provides a program control device which causes a control amount of a localization system control target to follow a predetermined target value pattern, comprising: Target value pattern setting means for setting a target value pattern by connecting each time interval of the program pattern given by the coordinates of the target value of the target value pattern, and each time interval of the target value pattern set by the target value pattern setting means. Means for adding a steady-state error amount generated in step (a), and changing the boundary of each time section of the target value pattern to which the steady-state error amount is added by the steady-state error amount adding means to make the target value pattern continuous Target value pattern continuation means, steady gain measuring means for measuring a steady gain of the localization system control target, and a target value made continuous by the target value pattern continuation means And a target value pattern correcting means for correcting the pattern based on the steady gain measured by the steady gain measuring means.

Therefore, according to the present invention, in both cases of the steady-state change amount in the section where the target value changes in a ramp shape and the overshoot amount when the target value becomes a constant value from the ramp shape, the value is minimized as much as possible. It is possible to appropriately follow the control amount of the localization system control target to a predetermined target value pattern,
There are effects such as that a program control device with improved control performance can be obtained.

<< Embodiment >> Hereinafter, an embodiment of a program control device of the present invention will be described with reference to the drawings.

The same components as those of the conventional example are denoted by the same reference numerals, and the description of these components will be duplicated.

FIG. 1 is a block diagram showing a first embodiment of the program control device of the present invention.

In the figure, reference numeral 5 denotes a correction unit. The correction unit 5 controls a control parameter and a control of a control unit configured by applying a given target value pattern to a PID control device 2, a target value feedforward unit 3, and a steady gain output unit 4. The correction is made based on the steady gain K of the object 1.

In the figure, reference numeral 6 denotes a steady gain measuring section, which is provided to more accurately execute the target value pattern correction of the correcting section 5.

That is, in correcting the target value pattern, the measured steady gain K of the control target 1 is used in addition to the parameters of the control unit itself, such as the control parameters of the control unit (not shown).

Therefore, in the case of the control target 1 in which the steady gain K fluctuates during the control, the steady gain K in the case where the steady gain K fluctuates must be measured by some method (see the second embodiment described later). in the case of).

However, when the fluctuation of the steady gain K of the control target 1 during the control is small, it is sufficient that the steady gain K obtained in advance is a fixed value, and the first embodiment is a block diagram in this case.

The input of the steady gain measuring section 6 differs depending on the method of measuring the steady gain K.

According to the thus configured program control device, the program control result is as shown in FIG. 3, and the target value pattern r (r) indicated by a broken line is represented by a dashed-dotted line -￣-.
The correction target value pattern is created by the correction unit 5 and is used as the target value of the two-degree-of-freedom PID control unit 2, thereby realizing program control that satisfies the following two points.

That is, the steady-state deviation in the section where the target value changes in a ramp shape can be suppressed to a small value, and the amount of overshoot when the target value changes from the ramp shape to a constant value can also be suppressed to a small value.

The reason for this is as follows. First, the control unit has two degrees of freedom PID to realize the above. Such a case is not satisfied, but the correction may be performed by the target value pattern correction unit 5 so as to satisfy the above.

FIG. 8 is a block diagram showing a second embodiment of the program control device according to the present invention, and FIG. 2 is an operation flowchart thereof.

This embodiment differs from the first embodiment in that the deviation between the corrected target value pattern and the controlled variable of the control target 1 is input to the steady-state gain measuring section 6 '.

In this embodiment, when the program pattern is given by coordinates of a time and a target value pattern at that time, the correspondence between the coordinates and the target value pattern, that is, the program pattern diagram is as shown in FIG.

Next, the operation flow here will be described for each stage by the flow shown in FIG.

In the first stage, the program pattern is converted,
When a program pattern given by the coordinate format (tk, r (tk)), k = 0, 1, 1... N is represented in a linear expression for each time interval, the following is obtained.

When t _k <t of _{<t k + 1, r (} t) = a k t + b k, k = 0,1, ..., n-1 ... (1) formula In the second stage, biasing is performed as follows.

When the steady-state deviation amount generated for each time interval is biased to the linear equation obtained by the equation (1), the following is obtained.

When t _k <t <t _{k + 1} , r _b (t) = a _k t + b _bk , k = 0, 1,..., n−1 (2) In the third stage, the post-bias target value rb (t) of each time interval obtained by the equation (2) is not continuous at the time interval boundary, so that the time interval boundary is changed to be continuous.

As a method, an intersection point when rb (t) of each time interval is extended is obtained, and is set as a new boundary. That is, it is represented by the following equation.

When t ′ _k <t <t ′ _{k + 1} , r _m (t) = _ak · t + b _bk , k = 0, 1,..., n−1 (3) In the fourth stage, the steady-state gain is measured. Includes a steady gain K to be controlled. Steady gain K
May fluctuate during control, and it may be better to always measure it.

(However, if there is little fluctuation during control,
You can omit stages. The measurement method here is as follows. In the section of ak = 0, if K deviates from the true value, the bias amount of the target value also deviates, so that a steady-state error remains, and a steady-state gain is estimated from the steady-state error.

However, the steady-state deviation es is a deviation between the target value after the bias and the control amount when the control value is settled to a sufficiently constant value.

The steady gain K obtained here is used in the second stage of the next bias addition.

FIG. 5 shows the correction result in the second stage. At this stage, since the bias value is added to the target value r (t) for each time section, no steady-state error remains. However, at the boundary of the time section, the target value is discontinuous, and the occurrence of overshoot cannot be avoided.

In FIG. 6, the boundaries of the time sections are moved so that rb (t) for each time section is continuous.

This means that the target value in the next time section is predicted, and overshoot can be suppressed.

FIG. 7 shows rn (t) when the steady-state gain K is changed at time tkm in the measurement result of the fourth stage of the value. Seventh
As can be seen from the figure, the time section boundary t'k after time tkm
Are moving with respect to FIG.

From the above description, if the target value pattern is modified as shown in FIG. 7, a control result as shown in FIG. 3 can be obtained.

That is, this embodiment also has the same operation and effect as the first embodiment.

Note that the steady-state gain measurement unit shown in the fifth stage may output a value obtained in advance according to the control amount, for example, without actually measuring it.

Further, it can also be obtained from the ratio of the operation amount and the control amount in the set state at the time of constant value control.

Further, the operation flowchart of FIG. 2 is a flow for correcting the target pattern every control synchronization.
This is because the control parameter (K
p, Ti, α) and the steady gain K.

In other words, the recalculation may be performed only when there is a change in the parameter used for the bias amount calculation. If there is no change, only once after the target value pattern r (t) is given.
rm (t) may be calculated.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of a program control device of the present invention, FIG. 2 is an operation flowchart showing an operation flow of a second embodiment of the program control device of the present invention, and FIG. Control waveform diagram showing the correction target value of
FIG. 4 is a waveform diagram showing a state of a program pattern in the present invention, FIGS. 5 to 7 are control waveform diagrams showing an output state of a correction target value in each stage of the second embodiment, and FIG.
FIG. 1 is a block diagram showing a second embodiment of the program control apparatus of the present invention. FIG. 9 is a block diagram showing a conventional program control apparatus. FIGS. 10 and 11 are control waveforms of the conventional program control apparatus. FIG. 1 ... Localization system control target 5 ... Correction unit 6 ... Stationary gain measurement unit K ... Stationary gain

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-61-290505 (JP, A) JP-A-56-27404 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G05B 11/00-13/04 G05D 3/12

Claims (1)

(57) [Claims] 1. A program control device in which a control amount of a localization control target is made to follow a predetermined target value pattern, wherein each time of a program pattern given by coordinates of a time and a target value at that time. Target value pattern setting means for setting a target value pattern by connecting sections with a straight line; and steady deviation amount adding means for adding a steady deviation amount occurring in each time interval to the target value pattern set by the target value pattern setting means. And target value pattern continuation means for changing the boundary of each time interval of the target value pattern to which the steady deviation amount is added by the steady deviation amount adding means to make the target value pattern continuous, and A steady-state gain measuring means for measuring a steady-state gain, and a constant value measured by the steady-state gain measuring means. Program control device, characterized in that provided a target value pattern correction means for correcting, based on the gain, the.