JPH04312376A - Drive controller for rotating machine - Google Patents

Abstract

PURPOSE:To obtain the drive controller for a rotating machine which can suppress the overshoot of revolution. CONSTITUTION:A calculated current instruction value (h) is obtained by proportional integration of a proportional integrating means 6 in accordance with a revolution error (c) between an instructed revolution (a) and a fed-back actual revolution (b). The obtained calculated current instruction value (h) is limited by an operation rate calcurating means 7 in accordance with a range within a predetermined limiting value and the limited instruction value is outputted as a current instruction (i) of the operation rate corresponding to the revolution error. An integrated value control means 8 which controls the integrated value (d) of the proportional integrating means 6 when the calculated current instruction value (h) exceeds the limiting value, so that the calculated current instruction value (h) can be kept close to the limiting value even if it exceeds the limiting value.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive control device for a rotating machine that controls the movable parts of industrial machines, machine tools, and the like.

0002

2. Description of the Related Art Hitherto, it has been known to use proportional-integral control in the speed control section of a drive control device for a rotating machine that controls the movable parts of industrial machinery, machine tools, etc.

FIG. 4 is a block diagram schematically showing an example of a conventional drive control device for a rotating machine using such proportional-integral control. In the figure, 1 is a rotating machine or motor that drives the movable parts of industrial machines and machine tools, and 2 is a motor 1.
Speed detection means detects the rotational speed of the motor 1 and feeds it back as the actual rotational speed b of the motor 1, 3 is a speed command a for rotating the motor 1 at a target speed and the fed-back actual rotational speed b 4 is a current control unit that controls the current to the motor 1 based on a command from the speed control unit 3. Here, S/W by a microprocessor is used.
control is used.

The speed control unit 3 includes a speed error detection means 5 for determining a speed error c between the set speed of the speed command a and the actual rotational speed b, and outputting the speed error signal as a speed error signal; A proportional integration means 6 calculates a current command calculation value h to the motor 1 based on the speed error c, and a proportional integration means 6 limits the current command calculation value h calculated by the proportional integration means 6 based on a predetermined output range. , and a manipulated variable calculation means 7 which outputs the value to the current control means 4 as a current command i of the manipulated variable according to the speed error c.

The proportional integration means 6 integrates the speed error c obtained by the speed error detection means 5 to obtain an integral value d, and multiplies this integral value d by an integral time constant e as an integral output f. The speed error c obtained by the speed error detection means 5 is added to the value of this integral output f, and the value obtained by multiplying this added value by the speed gain g is set as the current command calculation value h to the motor 1 by the operation amount calculation means 7 Output for.

Next, the operation of the conventional device having the above-mentioned configuration will be explained based on the flowchart shown in FIG. First of all,
A speed command a is input to the speed control section 3 (step 1), and the motor 1 is driven based on the speed command a. When the motor 1 is driven, the speed detection means 2 feeds back the speed of the motor 1 at this time to the speed error detection means 5 as the actual rotational speed b.

When the actual rotational speed b fed back from the speed detection means 2 is input, the speed error detection means 5 calculates the speed error c between the actual rotational speed b and the set speed of the speed command a, and detects the speed error. Output as a signal (step 2).

Next, the proportional integration means 6 adds the integral value d and the speed error c obtained by the speed error detection means 5 to obtain an integral value d.
(Step 3), and then multiply the updated integral value d by the integral time constant e to create an integral output f (Step 4).
, further add the created integral output f and the speed error c obtained by the speed error detection means 5, and add the speed gain g to this added value.
A current command calculation value h is created by multiplying the current command calculation value h (step 5), and the created current command calculation value h is outputted to the manipulated variable calculation means 7.

When the current command calculation value h is inputted from the proportional integration means 6, the operation amount calculation means 7 limits this current command calculation value h based on a predetermined output range, and sets the value to the speed error c. (step 6), and outputs the created current command i to the current control means 4.

When the current command i is input from the operation amount calculation means 7, the current control means 4 controls the current to the motor 1 based on this current command i (step 7), and drives the motor 1 (step 8). ).

[0011]

[Problems to be Solved by the Invention] Since the conventional drive control device for a rotating machine is constructed as described above, it is difficult to control the motor 1.
The relationship between the current flowing to the motor and the resulting rotational speed is as shown in the control characteristic diagram shown in FIG.

That is, when the current command calculated value h exceeds a limit value predetermined in the manipulated variable calculating means 7, the manipulated variable calculating means 7 calculates the current command i, which is the manipulated variable, as shown in the lower part of FIG. As shown, the current command calculated value h continues to increase even if it exceeds the limit value, unless the rotation speed of the motor 1 reaches the set value of the speed command a. If a difference occurs between the current command calculation value h and the limit value in this way, a runaway state of control will occur in the area A indicated by diagonal lines in the lower part of FIG. Areas B and C shown in
There was a problem in that a large rotation speed overshoot occurred in some parts.

SUMMARY OF THE INVENTION In view of the above points, it is an object of the present invention to provide a drive control device for a rotating machine that can reduce overshoot in the rotational speed.

[0014]

[Means for Solving the Problems] A drive control device for a rotating machine according to the present invention detects a rotating machine that drives an industrial machine, a machine tool, etc., and the rotation speed of this rotating machine, and detects the rotation speed of the rotating machine. a speed detection means for feeding back as an actual rotational speed; and a speed detection means for providing feedback as an actual rotational speed; and a speed command for rotating the rotating machine at a target speed, and a set speed of the speed command and the actual rotational speed based on the fed-back actual rotational speed. A speed error detection means that calculates the speed error with respect to the speed and outputs it as a speed error signal, and a value obtained by integrating the speed errors found by this speed error detection means to obtain an integral value, and multiplying this integral value by an integral time constant. is an integral output, the speed error obtained by the speed error detection means is added to the value of this integral output, and the value obtained by multiplying this added value by a speed gain is output as the calculated value of the current command to the rotating machine. and a manipulated variable calculation that limits the current command calculation value calculated by the proportional integral means based on a predetermined output range and outputs the value as a current command of the manipulated variable according to the speed error. means and
When a current command is input from this manipulated variable calculating means, this current command is output as is, and at the same time, the limit value of the manipulated variable calculating means is compared with the current command calculated value which is the output value of the proportional integral means, and the current command is calculated. If the value exceeds the limit value, the current command calculation value is divided by the speed gain, the speed error is subtracted from this divided value, and the subtracted value is further divided by the integral time constant. integral value control means for calculating an integral value of and current control means for controlling the current.

[0015]

[Operation] In the present invention, when a rotating machine that drives an industrial machine, a machine tool, etc. rotates, the speed detection means detects the rotational speed of this rotating machine and uses the detected speed as the actual rotational speed of the rotating machine. Feedback to the detection means. The speed error detection means determines the speed error between the fed-back actual rotational speed and the set speed of the speed command and outputs it to the proportional integration means. The proportional integration means integrates the input speed errors to obtain an integral value, multiplies this integral value by an integral time constant as an integral output, and adds the speed error determined by the speed error detection means to the value of this integral output. and outputs a value obtained by multiplying the added value by a speed gain to the operation amount calculation means and the integral value control means as a current command calculation value to the rotating machine. The operation amount calculation means limits the input current command calculation value based on a predetermined output range, and outputs the value to the integral value control means as a current command of the operation amount according to the speed error. When the current command is input from the manipulated variable calculation means, the integral value control means outputs the current command as it is, and at the same time compares the limit value of the manipulated variable calculation means with the current command calculation value which is the output value of the proportional integral means. , if the calculated current command value exceeds the limit value, divide the calculated current command value by the speed gain, subtract the speed error from this divided value, and then divide the subtracted value by the integral time constant. By doing so, the original integral value is determined and outputted to the proportional integration means to subtract this determined value from the original integral value. The current control means controls the current to the rotating machine based on the current command input from the integral value control means.

[0016]

EXAMPLES The present invention will be explained below with reference to illustrated examples.

FIG. 1 is a block diagram schematically showing a drive control device for a rotating machine according to an embodiment of the present invention. In addition, in the drawings, the same reference numerals are given to the parts corresponding to the conventional ones, and the explanation thereof will be omitted. In the figure, 8 is an integral value control means that controls the integral value d of the proportional integral means 6 when the current command calculated value h exceeds the limit value of the manipulated variable calculating means 7, and the other configuration is the same as the conventional one. It is.

That is, when the current command i is input from the operation amount calculation means 7, the integral value control means 8 controls the current command i.
is output as is to the current control means 4, and at the same time, the limit value of the manipulated variable calculation means 7 and the current command calculated value h from the proportional integral means 6 are compared, and if the current command calculated value h exceeds the limit value, The current command calculation value h is divided by the speed gain g, the speed error c is subtracted from this divided value, and the subtracted value is further divided by the integral time constant e to obtain the original integral value. It outputs to the proportional integration means 6 to subtract the obtained value and the original integral value d.

Next, the operation of the apparatus of this embodiment having the above-mentioned configuration will be explained based on the flowchart of FIG. Note that the processing operations from step 11 to step 16 are the same as the processing operations from step 1 to step 6 explained in FIG.
The explanation will focus on the operation.

That is, the integral value control means 8 performs step 1.
When the current command i created in step 6 is input from the manipulated variable calculation means 7, the integral value control means 8 outputs this current command i as it is to the current control means 4, and at the same time sets it as the limit value of the manipulated variable calculation means 7. The current command calculated value h from the proportional integration means 6 is compared to determine whether the current command calculated value h exceeds the limit value, that is, whether or not the output range is limited by the manipulated variable calculation means 7. (Step 17) If the output is being limited, it is determined that the current command calculated value h exceeds the limit value, the current command calculated value h is divided by the speed gain g, and the speed error c is calculated from this divided value. The original integral value is obtained by subtracting , and the subtracted value is further divided by the integral time constant e (step 18), and the proportional integration means 6 is instructed to subtract this obtained value from the original integral value d. It outputs and changes the integral value d.

When the current command i is input from the integral value control means 8, the current control means 4 controls the current to the motor 1 based on this current command i (step 19), and
(step 20).

Since the apparatus of this embodiment is constructed as described above, the relationship between the current flowing to the motor 1 and the resulting rotation speed is as shown in the control characteristic diagram shown in FIG.

That is, when the calculated current command value h exceeds the limit value, the integral value control means 8 adjusts the integral value d of the proportional integration means 6 so that the value of the calculated current command value h approaches the limit value. and reduce rotational speed overshoot.

[0024]

[Effects of the Invention] As described above, according to the present invention, even if the calculated current command value exceeds the limit value, the calculated current command value can be kept close to the limit value. ,
This has the effect of avoiding a control runaway state and reducing overshoot of the rotational speed.

[Brief explanation of drawings]

FIG. 1 is a schematic block diagram of an embodiment of the present invention.

FIG. 2 is a flowchart of the operation of the embodiment of the present invention.

FIG. 3 is a control characteristic diagram of the embodiment of the present invention.

FIG. 4 is a schematic block diagram of a conventional device.

FIG. 5 is a flowchart of the operation of the conventional device.

FIG. 6 is a control characteristic diagram of a conventional device.

[Explanation of symbols]

1 Motor (rotating machine) 2 Speed detection means 3 Speed control section 4 Current control means 5 Speed error detection means 6 Proportional integral means 7 Operation amount calculation means 8 Integral value control means a Speed command b Actual rotation speed c Speed error d Integral value e Integral time constant f Integral output g Speed gain h Current command calculation value i Current command

Claims (1)

[Claims] 1. A rotating machine that drives an industrial machine, a machine tool, etc., a speed detection means for detecting the rotational speed of the rotating machine and feeding back the detected speed as the actual rotational speed of the rotating machine, and a rotating machine that drives the rotating machine. Based on a speed command for rotating at a target speed and the fed-back actual rotation speed, a speed error between the set speed of the speed command and the actual rotation speed is determined and output as a speed error signal. The error detection means integrates the speed error obtained by this speed error detection means to obtain an integral value, and the value obtained by multiplying this integral value by an integral time constant is used as an integral output. a proportional integral means that adds the speed error determined by the detection means, multiplies the added value by a speed gain, and outputs the value as a calculated current command value to the rotating machine; and a current command calculated value calculated by the proportional integral means. is limited based on a predetermined output range and outputs the value as a current command of the manipulated variable according to the speed error, and when a current command is input from the manipulated variable calculation means, this At the same time as outputting the current command as it is, the limit value of the manipulated variable calculating means is compared with the current command calculated value which is the output value of the proportional integral means, and if the current command calculated value exceeds the limit value, the current command is Divide the calculated value by the speed gain, subtract the speed error from this divided value, and divide the subtracted value by the integration time constant to obtain the original integral value. and an integral value control means for outputting an output to the proportional integral means so as to subtract an integral value from the integral value; and a current controlling means for controlling a current to the rotating machine based on a current command from the integral value controlling means. Drive control device for rotating machines.