JPH07135790A - Signal generator - Google Patents

Abstract

PURPOSE:To control a control object including a motor smoothly and accurately in response to the state of the object. CONSTITUTION:A signal generating part 13 having a coarse resolution, a signal generating part 14 having a fine resolution and a selection control part 17, which selects either of the signal generating part 13 or 14 based on the preset value of the operating amount from a setting part 11 and the difference between both outputs of the signal generating parts 13 and 14, are provided. A control object 3 is controlled with the output from the signal generating part 14 when the operating amount is largely changed and with the output from the signal generating part 13 in the other cases. Thus, the smooth, accurate control can be performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal generator suitable for use in, for example, a speed command unit of a plant including a variable speed controller for operating various controlled objects at a variable speed.

[0002]

2. Description of the Related Art Conventionally, as a signal generator of this type,
It is usually configured as follows. (1) The signal generating means is of one type, and therefore the selecting means is unnecessary. (2) The number of program cycles for operating the signal generating means is usually only one. (3) When the program cycle for operating the signal generating means becomes long, the change amount dV / dt of the speed command becomes large,
Since the torque ripple of the variable speed control device becomes excessively large, a setting filter is inserted into the input end of the variable speed control device to deal with the problem.

[0003]

A programmable controller (PC) is often used as a variable speed control device, and this PC usually manages many programs. That is, in order to improve control accuracy and realize smooth operation, it is better to use a higher-level program (short-cycle program). However, the large number of programs of this type impedes the execution of low-level programs. Therefore, if the above items (2) and (3) are performed, the transmission cycle of the speed command (at the time of change) becomes rough and dV.
Since / dt becomes excessive, the torque ripple increases,
As a result, there is a problem that the product quality of the plant is deteriorated (fine vibration, generation of flaws, etc.). Therefore,
It is an object of the present invention to provide a plurality of signal generating means and select them so that the plant operates smoothly.

[0004]

In order to solve such a problem, in the first aspect of the invention, a setting unit for setting an operation amount of a control device for controlling a controlled object including an electric motor and a setting unit for the operation amount are respectively provided. The first and second control resolutions (the first control resolution is coarse and the second control resolution is fine); A change determination unit that determines whether or not there is a temporal change, and a coincidence determination unit that compares the operation amount outputs from the first and second signal generation units and determines whether or not they match. , A selection control unit that selects one of the first and second signal generation units according to the output from the coincidence determination unit and the output from the change determination unit, and the selection control unit selects Holds the output of the signal generator and controls the control target including the motor. It is characterized in that a signal holding-output unit for outputting as the optimum operation amount Te.

According to the first aspect of the invention, when the above-mentioned respective parts are realized by the program processing means, the order of execution of the programs is the order of the first signal generating part, the second signal generating part and the signal holding / outputting part. The output of the first signal generator can be overwritten by the output of the second signal generator, and the sampling period of each unit is t0 milliseconds for the signal holding / output means, and the second signal When the generator is t2 milliseconds and the first signal generator is t1 milliseconds, t1>t2> t0.
Can meet the relationship.

According to the second aspect of the invention, a setting unit for setting the operation amount of a control device for controlling a controlled object including an electric motor, and first and second control resolutions (first control amount) for the operation amount, respectively. (The control resolution is coarse and the second control resolution is fine), and it is determined whether or not the first and second signal generators that generate the manipulated variable output and the manipulated variable change with time. A change determination unit that compares the operation amount outputs from the first and second signal generation units to determine whether the two match, and an output from the match determination unit and the change A selection control unit that turns on and off the second signal generation unit according to an output from the determination unit;
The output from the signal generating section is selected, and when the second signal generating section is turned on by the selection control section, the priority selecting section which selects the output, and the output from the priority selecting section The present invention is characterized in that a signal holding / output unit for outputting an optimum manipulated variable to a control target including an electric motor is provided.

[0007]

By providing the first and second signal generators for generating the manipulated variable outputs with different control resolutions for the manipulated variable set value and the selection control section thereof, it is possible to adjust the texture according to the state of the controlled object. Enables fine control.

[0008]

1 is a block diagram showing an embodiment of the present invention. In the figure, 1 is a signal setting unit 11, a signal change determination unit 12, signal generation units 13 and 14, and a signal storage / output unit 1.
5, a signal generator including a signal coincidence determination unit 16, a signal generator selection unit (selection control unit) 17, and the like, 2 is a signal transmission path, and 3 is a plant such as a variable speed control device. In addition,
The signal generator 1 can be realized by either hardware or software.

Based on the manipulated variable setting signal V from the signal setting unit 11, the signal generating units 13 and 14 have different resolutions (here, the resolution of the signal generating unit 13 is coarse and the resolution of the signal generating unit 14 is fine). Operation amount signal V
Output ₁ ', V ₂ '. The signal storage / output unit 15 stores the manipulated variable signals V ₁ ′ and V ₂ ′ from the signal generation units 13 and 14, and outputs them to the variable speed control device 3 via the signal transmission line 2.

The signal generator selection unit (selection control unit) 17 determines which of the outputs from the signal generation units 13 and 14 should be given to the signal storage / output unit 15. For example, as shown in FIG. And a flip-flop 17B. That is, the signal generator selection unit (selection control unit)
The output from the signal change determination unit 12 and the output from the signal coincidence determination unit 16 are input to 17 and the signal generation units 13 and 14 are input.
Select either one of. The signal change determination unit 12 monitors the change in the manipulated variable V, outputs a high level signal when the change is large, and the signal coincidence determination unit 16 determines that the manipulated variable signals V ₁ 'and V ₂ ' are substantially equal. When the difference can be regarded as zero, a high level signal is output.

Therefore, the signal generator selection section (selection control section) 17 selects the signal generation section 14 by setting the flip-flop 17B via the AND gate 17A when the change in the manipulated variable V is large. When the change in the amount V is small and the manipulated variable signals V ₁ 'and V ₂ ' are substantially coincident with each other, the flip-flop 17B is reset to select the signal generator 13.

FIG. 3 is a graph showing an example of setting the manipulated variable, and FIG.
Is a detailed view thereof. Hereinafter, FIG. 1 will be described with reference to these drawings. Now, in the signal setting unit 11, the operation amount for the plant 3 is set as shown in FIG. 3,
Assuming that the sampling periods in the signal generators 13 and 14 are t1 and t2 (t1 = 5t2), respectively, FIG.
When the section T1 is switched to the section T2, the outputs V ₁ ′ and V ₂ ′ of the signal generators 13 and 14 are as shown by the solid and dotted lines in FIG. 4 (a / b = 1/5 = 20
%).

Since the change in the manipulated variable V is large in the section T1, the output of the signal change determination section 12 becomes high level, which sets the flip-flop 17B and the signal generation section 14 is selected. It will be.
On the other hand, in the section T2, there is almost no change in the manipulated variable V, and since it is considered that V ₁ 'and V ₂ ' are almost equal to each other, the flip-flop 17B is reset and the signal generator 13 is Will be selected.

That is, for the setting as shown in FIG. 3, the signal generator 14 is selected in the sections T1 and T3, and the signal generator 13 is selected in the section T2. By doing so, when the manipulated variable greatly changes, the output from the signal generating unit 14 having a fine resolution indicates that the manipulated variable does not significantly change and V ₁ 'and V ₂ ' substantially match each other. When considered, it becomes possible to control the plant 3 respectively by the output from the signal generating unit 13 having a coarse resolution, and it is possible to perform accurate control according to the state of the controlled object.

FIG. 5 is a block diagram showing another embodiment of the present invention. As is apparent from the figure, a feature is that a signal priority determination section (priority selection section) 18 is added to that shown in FIG. In addition, the signal generator selection unit (selection control unit) 1
7, the signal generator 13 is normally selected here (the signal generator 14 is turned off), and when a predetermined condition is satisfied, the signal generator 14 is turned on and selected. The other points are the same as in FIG.

The predetermined condition is the same as in the case of FIG. 1 when the signal change judging unit 12 judges that the change in the manipulated variable V is small, and when the condition is satisfied, the signal generating unit 14 is turned on. To do. As a result, the signal generator 1
Since the signal generator 14 is selected instead of 3, it is possible to perform appropriate control according to the state of the control target, as in the case of FIG.

In the above description, it is assumed that each part of the signal generator 1 is composed of hardware, but the case of being realized by software will be described below. In this case, the program is executed in the order of the first signal generating section, the second signal generating section, and the signal holding / output section, and the output of the first signal generating section is the second signal generating section. Try to overwrite the output of. This makes it possible to provide the same function as in FIG. 1, and the signal priority determination unit (priority selection unit) 18 required in FIG. 5 can be omitted.

Further, regarding the sampling cycle of each part,
When the signal holding / output means is t0 msec, the second signal generating part is t2 msec, and the first signal generating part is t1 msec, the relationship of t1>t2> t0 is satisfied. For example, if t1> 5t2, the speed change rate and the torque ripple rate are reduced to about 1/5 (20%), and smoother control is possible about 5 times as much as before when acceleration / deceleration is performed, while program speed control is performed at constant speed. It becomes possible to minimize the occupation time.

[0019]

According to the present invention, the first and second signal generators for generating the manipulated variable outputs with different control resolutions for the manipulated variable set value and the selection control section thereof are provided. In performing the variable speed control of the plant, there is an advantage that smooth control can be performed without particularly increasing the occupation time of the program.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a configuration diagram showing a specific example of a signal generator selection unit in FIG.

FIG. 3 is a graph showing a setting example of an operation amount.

FIG. 4 is a partially enlarged view of FIG.

FIG. 5 is a configuration diagram showing another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Signal generator, 2 ... Signal transmission path, 3 ... Variable speed control apparatus (plant), 11 ... Signal setting part, 12 ... Signal change determination part, 13, 14 ... Signal generating part, 15 ... Signal storage / transmission part , 16 ... Signal coincidence determination section, 17 ... Signal generator selection section (selection control section), 18 ... Signal priority determination section (priority selection section), 17A ... AND gate, 17B ... Flip-flop.

Claims (4)

[Claims] 1. A setting unit for setting an operation amount of a control device for controlling a controlled object including an electric motor, and first and second control resolutions for the operation amount (the first control resolution is made coarse). , A second control resolution is made dense), first and second signal generators that generate an operation amount output, and a change determination unit that determines whether or not the operation amount changes with time. A match determination unit that compares the operation amount outputs from the first and second signal generation units and determines whether or not they match, an output from this match determination unit, and an output from the change determination unit. A selection control unit that selects one of the first and second signal generation units according to the above, and a control target that includes an output of the signal generation unit selected by the selection control unit and that includes the electric motor. Hold the signal output as the optimum manipulated variable
A signal generator comprising an output section. 2. When the respective units are realized by a program processing unit, the order of execution of the programs is the order of the first signal generating unit, the second signal generating unit and the signal holding / outputting unit, and The signal generator according to claim 1, wherein the output of the first signal generator overwrites the output of the second signal generator. 3. When each unit is realized by a program processing unit, the sampling cycle of each unit is t0 milliseconds for the signal holding / outputting unit, t2 milliseconds for the second signal generating unit, and the first signal generating unit. Be t1 milliseconds, t1>t2>
The signal generation device according to claim 1, wherein the signal generation device satisfies the relationship of t0. 4. A setting unit for setting an operation amount of a control device for controlling a controlled object including an electric motor, and first and second control resolutions for the operation amount (the first control resolution is made coarse). , A second control resolution is made dense), first and second signal generators that generate an operation amount output, and a change determination unit that determines whether or not the operation amount changes with time. A match determination unit that compares the operation amount outputs from the first and second signal generation units and determines whether or not they match, an output from this match determination unit, and an output from the change determination unit. A selection control unit for turning on / off the second signal generation unit, and usually, an output from the first signal generation unit is selected, and the selection control unit turns on the second signal generation unit. When this occurs, the priority selection section that selects that output and this priority selection section And a signal holding / output unit which holds the outputs of the above and outputs the optimum manipulated variable to a controlled object including the electric motor.