JPH0619502A - Automatic controller - Google Patents

Abstract

PURPOSE:To output a manipulated variable from which residual vibration is removed to a controlled system by simple constitution. CONSTITUTION:When a proportional plus differential element arithmetic part 7 performs proportional plus differential operation for a deviation signal and then outputs a phase plane signal, equivalent proportional plus integral operation is carried out by a proportional element arithmetic part, an integral element arithmetic part 5, etc., which constitute serial pulses and a 1st manipulated variable is outputted; and an addition part 10 adds this 1st manipulated variable 5a and a 2nd manipulated variable 8a outputted from a relay element part 8 together.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic control device for automatically controlling an object to be controlled so as to match a control amount with a desired value, and particularly to a high-order vibration mode such as a precision positioning system and a flexible structure system. The present invention relates to an automatic control device that requires residual vibration removal due to non-linear friction of a drive unit.

[0002]

2. Description of the Related Art FIGS. 5 and 6 are diagrams for explaining a feedback loop control system in a conventional controller.

In these figures, 1 is a controlled object, 2 is a manipulated variable for the controlled object 1, and 3 is a controlled variable, which is subtractively input to a comparator COM. OBJ is the target value, comparator C
It is added to OM. 8 is a relay element. 9 is P
The ID calculator executes PID calculation on the positional deviation amount 4 and outputs the manipulated variable 2 to the controlled object 1.

The control system shown in FIG. 5 is a PID (proportional + integral + derivative calculation, and the differential term is omitted hereinafter) control system, and when parameters aiming at responsiveness are set,
Excitation of higher modes was unavoidable. Therefore, it has been limited to a field in which a slow response performance is required or a field of use in which the natural vibration mode exists in a sufficiently high range from the control frequency range.

The control system shown in FIG. 6 is used exclusively for compensating for a jumping element characteristic (which is expressed as a dead zone characteristic in the forward direction) such as Coulomb friction. Since the relay element 8 provided is a mechanism that operates only by the position (deviation) signal,
Considering the closed-loop characteristic consisting of this element and the controlled object, it is clear that there is a phase shift, and the expected damping is often not obtained. FIG. 7 shows a typical convergence locus in which the closed-loop characteristic including the relay element path is shown in the phase plane. In FIG. 7, the vertical axis represents the speed e1 and the horizontal axis represents the position deviation e2.

As shown in this figure, since the relay operation is performed on the vertical axis, not only high-speed operation cannot be expected, but when the phase delay is large, for example, the limit cycle (sustained vibration) shown in FIG. ) Was likely to occur.

[0007]

As described above, in the conventional control device, it is necessary to accept the passive parameter setting only by the linear control operation for the control target including the vibration component having the poor damping or the non-linear oscillation element. Not get
It was a slow response.

Further, when a non-linear compensation element that depends only on position information is added, it is difficult to set the relay width for stabilization, the damping characteristics cannot be greatly improved, and the limit cycle is likely to occur. .

Further, if the residual vibration compensation is rigorously performed, enormous cost is required, and further, the characteristic analysis in advance is indispensable, and even if the result is faithfully adopted to realize the control system, it is extremely complicated. However, there is a problem in that it is not possible to put it into practical use.

The present invention has been made to solve the above problems, and an object of the present invention is to obtain an automatic control device capable of removing residual vibration in a manipulated variable output to a controlled object with a simple structure. .

[0011]

In the automatic control device according to the present invention, the calculating means includes a proportional plus differential calculating section for performing a proportional plus differential operation on the deviation signal and outputting a phase plane signal.
An integral calculation unit that performs an equivalent proportional plus integration calculation on the phase plane signal output from the proportional plus differential calculation unit and outputs a first manipulated variable, and a rising edge from the phase plane signal that is higher than the first manipulated variable. An addition unit that adds a second operation amount and a first operation amount output from the relay element unit that outputs a slow second operation amount and outputs the operation amount to a control target And are provided.

[0012]

According to the present invention, when the proportional plus differential operation is performed on the deviation signal by the proportional plus differential operation unit and the phase plane signal is output, the equivalent proportional plus integral operation is performed by the integral operation unit forming the series path. Then, when the first manipulated variable is output, the addition unit adds the first manipulated variable and the second manipulated variable output from the relay element unit to remove residual vibration in the controlled object. It is possible to output a quantity.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram for explaining the configuration of a control device showing an embodiment of the present invention, in which the same parts as those in FIGS.

In the figure, CONT is a controller unit, which is a serial path consisting of a proportional plus differential element operation unit 7, a proportional element operation unit 6, and an integral element operation unit 5 in the forward direction, and a relay element unit 8 on a path bypassing the integration element. Is provided. The relay element portion 8 is also provided with a dead zone corresponding to the tolerance of the position deviation amount 4 (error tolerance value (see FIG. 3). Reference numeral 10 is an addition portion, which is a first operation amount 5a and a second operation amount 5a.
The operation amount obtained by the addition processing with the operation amount 8a of is output to the controlled object 1.

Further, the serial path is composed of elements obtained by modifying the PI operation shown in the following expression (1).

Kp (1 + 1 / TiS) = Kp. (1 + TiS) / TiS = (1 + TiS). (Kp / Ti). (1 / S) (1) Here, Kp is a proportional gain. , Ti represents the reset time. S is a Laplace operator.

The present invention focuses on the last term (the rightmost term in the equation) of the equation (1) to execute the control operation.
That is, although the preceding and middle terms of the above equation (1) merely represent a general PI operation format, the final term is a modification to the velocity type, and the gist thereof is the element (1+ By changing the viewpoint of (TiS), it can be interpreted as a phase plane signal captured on the phase plane consisting of position information and velocity information, and the element including the PI parameter Ti is shown in the following equation (2) on the phase plane. Represents a straight line.

E (indicating a differential value of the phase deviation e) = − (e / Ti) (2) However, when E> − (e / Ti), u is C, and otherwise, u Is -C. Here, u indicates the manipulated variable output, and c is a positive constant. The reason why the straight line of the equation (2) is switched under the above condition is that the straight line has a gradient, as is apparent from the equation (2), which has a function of compensating the phase delay of the vibration component. This is because it is possible to improve the damping characteristic.

As shown in FIG. 1, with respect to the position deviation amount 4, an equivalent PI calculation of the proportional gain Kp and the reset constant Ti is executed by the forward main path (the above series path), and the relay element portion 8 and the proportional path of the parallel path. The phase component control of the vibration component of the position deviation amount 4 is executed by the plus differential element calculation unit 7. According to the present embodiment, if the amplitude of the relay element portion 8 is set to zero or the dead zone is made sufficiently large, the PI control system is realized. As is apparent from the above, the conventional proportional gain Kp and reset time Ti are adopted as they are. Can be calculated. Further, since the dead band is directly given from the control use, the only adjustable parameter left is the relay amplitude, but the relay amplitude may be adjusted corresponding to the amplitude of the residual vibration, and the adjustment is easy.

In the automatic controller thus constructed, when the proportional plus differential operation unit (proportional plus differential element operation unit 7) performs the proportional plus differential operation on the deviation signal and outputs the phase plane signal, the serial signal is output. When the integral operation means (which is composed of the proportional element operation section 6 and the integral element operation section 5 in this embodiment) forming the path performs the equivalent proportional plus integral operation and outputs the first manipulated variable 5a. , Adder 10
Can add the first manipulated variable 5a and the second manipulated variable 8a output from the relay element section 8 to output the manipulated variable with the residual vibration removed to the controlled object 1.

FIG. 2 is a characteristic diagram showing the damping characteristic of the residual vibration in the automatic control device shown in FIG. 1. The vertical axis shows the speed e1 as the differential value of the phase deviation e2, and the horizontal axis shows the phase deviation. e2 is shown. The inclination of the switching line is determined by the above equation (2).

FIG. 3 is a diagram showing a step response characteristic in the automatic control device shown in FIG. 1, where the horizontal axis represents time (mse).
c) is shown.

As shown in these figures, the residual vibration due to the relay amplitude can be well damped.

In the above embodiment, the proportional plus differential element calculating section 7, the proportional element calculating section 6, and the integral element calculating section 5 are used.
Operation amount 2 by adding a serial path consisting of
However, there are various methods for simulating operations such as giving coefficient elements, differential operations, and integration operations, and there is no particular limitation in applying the present invention.

In the above embodiment, the case where the control system calculates and outputs the manipulated variable 2 by continuous calculation processing has been described. For example, as shown in FIG. 4, the manipulated variable 2 is calculated and output by discrete calculation processing. It may be configured to.

FIG. 4 is a block diagram for explaining the configuration of a control device showing another embodiment of the present invention. The same parts as those in FIG. 1 are designated by the same reference numerals.

As shown in this figure, the proportional plus derivative element calculator 7 calculates the following equation (3) for the position deviation amount 4.

(1 + τ) -τz-1 (3) where z-1 is a delay operator corresponding to the sampling period, τ is a time parameter, and the sampling time is Δ.
If t, the relationship with the reset time Ti in the above equation (1) is τ = Ti / Δt.

Further, the proportional element calculation unit 6 executes the calculation based on the following formula (4) on the calculation result by the proportional plus differential element calculation unit 7.

Proportional gain Kp / time parameter τ (4) Further, the integral element calculation unit 5 executes the calculation based on the following expression (5) on the calculation result by the proportional element calculation unit 6.

1 / 1-z-1 (5) With this configuration, the present invention can be easily applied to a control system that executes discrete time calculations.

Although the controlled object 1 is not particularly limited in the above embodiment, the present invention can be applied to any control system in which residual vibration needs to be taken into consideration.

[0033]

As described above, according to the present invention, when the deviation signal is subjected to the proportional plus differential operation by the proportional plus differential operation unit and the phase plane signal is output, it is equivalent by the integral operation means forming the serial path. When the proportional proportional plus integral calculation is performed and the first manipulated variable is output, the addition unit adds the first manipulated variable and the second manipulated variable output from the relay element unit. Therefore, even if the vibration component of the controlled object is directly related to the structural flexibility, or is caused by non-linearity, or due to disturbance, residual vibration can be generated with an extremely simple configuration. Can be removed.

Therefore, the countermeasures against vibration factors for the control system can be greatly improved, the economic burden required for conventional countermeasures against vibration can be greatly reduced, and the design burden on the developer can also be reduced, and the desired device can be developed. It has excellent effects such as shortening the period.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating a configuration of a control device showing an embodiment of the present invention.

FIG. 2 is a characteristic diagram showing a damping characteristic of residual vibration in the automatic control device shown in FIG.

FIG. 3 is a diagram showing a step response characteristic in the automatic control device shown in FIG.

FIG. 4 is a block diagram illustrating a configuration of a control device showing another embodiment of the present invention.

FIG. 5 is a diagram illustrating a feedback loop control system in a conventional control device.

FIG. 6 is a diagram illustrating a feedback loop control system in a conventional control device.

FIG. 7 is a characteristic diagram showing a convergence locus in which a closed-loop characteristic including a relay element path is shown on a phase plane.

FIG. 8 is a characteristic diagram showing a limit cycle peculiar to a feedback loop control system in a conventional control device.

[Explanation of symbols]

 1 controlled object 2 manipulated variable 3 controlled variable 4 position deviation amount 5 integral element calculation part 6 proportional element calculation part 7 proportional plus differential element calculation part 8 relay element part

Claims (1)

[Claims] 1. An automatic control device comprising an arithmetic means for arithmetically outputting an operation amount to be output to a controlled object from a deviation signal between a controlled variable and a target value, wherein the arithmetic means performs a proportional plus differential operation on the deviation signal. A proportional plus differential operation unit that executes and outputs a phase plane signal, and an integral that outputs an equivalent manipulated proportional plus integration operation to the phase plane signal output from the proportional plus differential operation unit and outputs a first manipulated variable. A computing unit, a relay element unit that outputs a second operation amount that rises later than the first operation amount from the phase surface signal, the second operation amount and the second operation amount that are output from the relay element unit. 1
And an adder that outputs the manipulated variable to the controlled object by performing addition with the manipulated variable.