JP2003311588A - Method of controlling industrial device and industrial device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of controlling an industrial device which stabilizes a speed control system even if a plurality of resonance peaks exist without merely relying upon lowering gain characteristics and provide an industrial device. <P>SOLUTION: In the method of controlling the industrial device provided with a drive section 210 which drives a control object 120, a detection section 220 which detects the position information of the control object 120 or the drive section 210, a speed command issuing section 230 which outputs a speed instruction defining the motion speed of the object 120 or the section 210 and a control processing section 240 which inputs the position information from the section 220, inputs the speed command from the speed command issuing section and controls the section 210 according to the position information and the speed command, the industrial device is stabilized by setting the phase characteristics of the input and output of the section 240 in a resonance frequency attributable to the undamped natural frequency of the object 120 by industrial device. The industrial device is controlled in the method of controlling the industrial device. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for controlling industrial equipment and an industrial equipment.

[0002]

2. Description of the Related Art Conventionally, servo control devices have been used for servo mechanisms of various industrial equipment such as machine tools, robots, injection molding machines, wire electric discharge machines, printing machines, electric presses and the like. For example, an NC machine tool has a table for fixing a work, a tool for cutting the work, and the like as control targets. These controlled objects are driven by a drive device such as a servo motor. The servo control device controls a control target and a drive device.

The servo control device operates the drive device or the controlled object at a prescribed speed based on the speed command in order to move the controlled object to a predetermined position. In order to control the speed of the driving device or the controlled object, the servo control device has a feedback loop that detects and feeds back either or both of the position of the controlled object and the rotational position of the driving device.

When detecting the position of the controlled object or the driving device in order to control the speed of the driven device or the controlled object, the position detector provided in the controlled object or the driving device determines the value of these positions according to the timing of the counter. Is latched and detected. The detected value of the detected position is fed back from the position detector to the servo controller as position feedback. The position detection value of the controlled object or the drive device is converted into speed feedback from the difference with the position detection value position fed back in the past. The difference between the speed feedback and the speed command is the speed error between the detected speed of the control target or the drive device and the speed command.

The speed command corrected by adjusting the speed error is filtered by a band pass filter in the servo controller, subjected to integral compensation processing, and subjected to proportional gain calculation to be converted into a torque command. The torque command is converted into a current command, and further, the current amplified based on the current command is supplied to the drive device. Thereby, the rotation speed of the drive device is controlled, or the speed of the controlled object is controlled.

Hereinafter, in the feedback loop, the process from feeding back the position detection value to supplying the current to the drive device is referred to as speed control process.

[0007]

Generally, the driven part to be controlled has a natural vibration. At the resonance frequency resulting from the natural frequency of the controlled object of this control system, the phase of the transfer characteristic of the control system is shifted by-(180 + 360 * n) degrees (n is an integer), and the gain in the speed control system is 0 dB. In the above case, the speed control system in the feedback loop becomes unstable. The instability of the speed control system means oscillation of the control system.

Conventionally, in order to avoid such instability of the speed control system, the speed control system has been designed so that the gain at the resonance frequency does not exceed 0 dB. For example, to suppress the gain in the resonance frequency range of the speed control system of the servo control device to be low, specifically, to suppress the gain at the resonance frequency by using a notch filter or reducing the proportional gain. Was done frequently.

However, when the notch filter or the like is provided, not only the gain is suppressed but also the phase delay of the control system increases. As a result, the gain at the resonance frequency is 0.
When there are a plurality of resonance peaks that are equal to or higher than dB, it may not be possible to deal with it by suppressing the gain low. For example, a ball screw has a resonance peak due to axial rigidity and a resonance peak due to torsional rigidity. If the gain of one of these resonance peaks is reduced by a notch filter or the like, the phase delay of the control system increases as the gain decreases, which may reduce the gain margin or phase margin at the other resonance peak. . As a result, the speed control system may oscillate.

Further, the reduction of the proportional gain leads to the reduction of the cutoff frequency of the speed control system, which leads to the reduction of the quick response and the dynamic accuracy of the speed control system.

Therefore, it is an object of the present invention to provide an industrial equipment control method and an industrial equipment in which the stability of the speed control system is improved without depending only on the reduction of gain characteristics.

Another object of the present invention is to provide an industrial equipment control method and an industrial equipment in which the stability of the speed control system is improved even when there are a plurality of resonance peaks.

[0013]

An industrial equipment control method according to an embodiment of the present invention provides a drive unit for driving a control target and position information of at least one of the control target and the drive unit. A detection unit that detects, a speed command generation unit that outputs a speed command that defines an operation speed of at least one of the control target and the drive unit, and the speed command generation unit that inputs the position information from the detection unit. From the position information and the speed command based on the position information and the speed command, and outputs a current command to the drive unit to control the drive unit. It is characterized in that the phase characteristic of the input / output of the control processing unit at the resonance frequency resulting from the natural frequency of the object is set for each of the industrial equipment.

Preferably, the phase characteristic of the input / output of the control processing unit at the resonance frequency is set to be shifted from-(180 + 360 * n) degrees (n is an integer of 0 or more).

Preferably, the input / output phase delay of the control processing unit at the resonance frequency is set to be larger than 180 degrees.

In the industrial equipment control method according to the embodiment of the present invention, the control target period or the detected speed of the drive unit and the control target calculated based on the period of the control cycle and the position information. Alternatively, the phase delay may be set by lengthening the dead time including the delay time based on the difference from the actual speed of the drive unit.

In the industrial equipment control method according to the embodiment of the present invention, a specific frequency range of a difference between the detected speed of the controlled object or the drive unit calculated based on the position information and the speed command is specified. Of the band-pass filter that removes a specific frequency band in the difference between the speed command and the detected speed of the controlled object or the drive unit calculated based on the position information. The phase delay may be set by changing the removal frequency.

The industrial equipment according to the present embodiment comprises a drive unit for driving a control target, a detection unit for detecting positional information of at least one of the control target and the drive unit, the control target or the drive unit. A speed command generation unit that outputs a speed command that defines the operation speed of at least one of the parts, and the position information is input from the detection unit and the speed command is input from the speed command generation unit; A control processing unit for controlling the drive unit by outputting a current command to the drive unit based on the information and the speed command, and inputting the control processing unit at the resonance frequency resulting from the natural frequency of the control target. The phase characteristic of the output is set for each industrial device.

Preferably, the phase characteristics of the input and output of the control processing unit at the resonance frequency are set to be shifted from-(180 + 360 * n) degrees (n is an integer of 0 or more).

Preferably, the phase delay of input / output of the control processing unit at the resonance frequency is set to be larger than 180 degrees.

In the industrial equipment according to this embodiment,
A dead time including a period of the control cycle and a delay time based on a difference between a detected speed of the control target or the drive unit calculated based on the position information and an actual speed of the control target or the drive unit. The phase delay may be set by increasing.

In the industrial equipment according to this embodiment,
The control processing unit is a band pass filter that passes a specific frequency range of the difference between the detected speed of the control target or the driving unit calculated based on the position information and the speed command, or the position information. Based on the control target or the drive unit having a band elimination filter for eliminating a specific frequency band in the difference between the detected speed of the drive unit and the speed command, the pass frequency of the band pass filter or the band elimination filter The phase delay may be set by changing the removal frequency.

In the industrial equipment according to this embodiment,
The controlled object is a drive mechanism, the natural frequency of the controlled object is a frequency caused by the rigidity of the drive mechanism, and the position information is the position of the drive mechanism or the rotational position of the drive unit. May be a feature.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to a machine tool, a robot,
In designing various industrial equipment such as injection molding machines, wire electric discharge machines, printing machines, electric presses, etc., the machine to be controlled and a servo control device for controlling the machine are set as a series to stabilize the entire industrial equipment. Improve sex.

Embodiments according to the present invention will be described below with reference to the drawings. The present embodiment does not limit the present invention.

FIG. 1 is a schematic block diagram of industrial equipment according to an embodiment of the present invention. The industrial equipment according to the present embodiment includes a control target 100 and a control target 1.
A speed control system 200 for controlling 00 is provided. The controlled object 100 is formed of a table 110 for fixing a work and a ball screw 120 for operating the table 110.

The speed control system 200 includes the ball screw 1
Servo motor 210 that rotationally drives 20, a detection unit 220 that detects position information of servo motor 210, a speed command generation unit 230 that outputs a speed command that defines the operating speed of servo motor 210, and a position from detection unit 220. The information is fed back, the speed command is input from the speed command generation unit 230, and the current command is output based on the position information and the speed command to control the servo motor 210. Current amplifier 250 that supplies current for driving the servo motor
With.

In the present embodiment, the detection section (for example, rotary encoder) 220 includes the servo motor 21.
The rotational position of 0 is detected and fed back to the speed control processing unit 240. However, the detection unit 130 that detects the position of the table 110 may be provided, and the detection unit 130 may feed back the position of the table 110 to the speed control processing unit 240. Further, both the detection unit 220 and the detection unit 130 may be provided. That is, the industrial equipment according to the present invention may employ any of the semi-closed loop control method, the closed loop control method, and the hybrid servo control method.

In the present embodiment, the embodiment to be controlled is the ball screw 120, but a feed drive mechanism such as a linear motor, a rack and pinion, a static pressure worm rack, a static pressure screw or the like may be used as the control target. . When a linear motor is used as the feed drive mechanism, the linear motor can also be used in place of the ball screw 120 and the servo motor 210 because the linear motor also functions as a drive unit. A rotation drive mechanism such as a belt drive can also be adopted as an embodiment of the controlled object. next,
The operation of the industrial device according to the present embodiment will be described, and further, the industrial device control method according to the embodiment of the present invention will be described.

FIG. 2 is a flow chart briefly showing the operation of the industrial equipment according to the present embodiment. First, the speed command generator 230 outputs a speed command that defines the operating speed of the servo motor 210 to move the table 110 to the target position (S10). The speed command generator 230 calculates a speed command based on a position command (not shown) from the outside.

Next, the speed control processing unit 240 inputs the speed command from the speed command generating unit 230, and supplies a current command to drive the servo motor 210 based on the detected position and the speed command fed back from the detecting unit 220. Is output (S20). That is, the speed control processing unit 240 executes speed control processing.

Next, the current amplifier 250 inputs a current command from the speed control processing unit 240, converts the current command into D / A, and outputs a current of a magnitude according to the current command to the servo motor 21.
0 (S30).

Next, the servo motor 210 receives the current from the current amplifier 250 and drives the ball screw 120 (S40).

The detection unit 220 detects the rotational position of the servo motor 210 and feeds back the detected rotational position to the speed control processing unit 240 (S50). When detecting the position of the servo motor 210, the position of the servo motor 210 is latched according to a certain timing of a counter provided in the detection unit 220, and this position is detected at the next timing.

Further, in S20, the speed control processing unit 240 executes speed control processing. The feedback from S10 to S50 and S50 to S20 is repeated until the table 110 moves to the target position. S50
From S20 to S20, the process from S20 to S50 is performed, and the process from S50 to S20 is further referred to as one control period.

FIG. 3 is a flow chart showing the operation of the speed control processing unit executed by the speed control processing unit 240 in S20. First, the speed control processing unit 240 reads the speed command from the speed command generating unit 230 and the detected position of the servo motor 210 (hereinafter, also referred to as position feedback) fed back from the detecting unit 220 (S20-
1).

Next, the speed control processing unit 240 compares the position feedback read in a certain control cycle with the position feedback read in the previous control cycle to compare the speed of the servo motor 210 (hereinafter, also referred to as speed feedback). ) Is calculated (S20-2). Here, using FIG. 4, speed feedback (S20-2)
The difference between the speed feedback and the actual speed will be described in more detail.

In FIG. 4, the detection unit 220 has the servo motor 21.
The timing chart after the position of 0 is detected until the speed control processing unit 240 calculates the speed feedback is shown. Here, the horizontal axis represents time t. On this time axis, the detection cycle of the position by the detection unit 220 is indicated by T.
The detection unit 220 detects the rotational position of the servo motor 210 at every cycle T. The detection cycle T is equal to the control cycle.
Therefore, hereinafter, the detection cycle is also referred to as a control cycle.

The broken line indicates the time point at which the counter provided in the detector 220 latches the position of the servomotor 210. The time between the latch and the detection of position feedback is indicated by Tl. In FIG. 4, the time t indicates four detection cycles (0 to 4T).

The vertical axis represents changes in V (t), θ (t), Pl (t), Pf (t) and Vf (t). Note that in FIG. 4, the relationship between the parameters is indicated by arrows. V (t) indicates the actual rotation speed of the servo motor 210. The servo motor 210 is assumed to rotate at a constant rotational acceleration A.
θ (t) indicates the actual rotational position of the servo motor 210.
Pl (t), the rotational position when the counter is latched in one control period theta (t) (hereinafter, referred to as a latch position) shown (see arrow x _t) reference. Pf (t) is, after latching the counter in the control period with the position of the servo motor 210 to detector 220 has detected (hereinafter, referred to as speed control detected position) (see the arrow y _t) indicating the. Vf (t) indicates the difference between the latch position Pl (nT) in a certain control cycle and the latch position Pl ((n−1) T) in the previous control cycle (hereinafter referred to as the detected speed) (arrow z _t reference). In addition, n is an integer.

The relationship is expressed by the following equation.

V (t) = tA (Equation 1) θ (t) = tV (t) (Equation 2) Pl (nT) = θ (nT−Tl) (Equation 3) Pf (nT) = Pl (nT) (Equation 4) Vf (nT) = {Pf (nT) −Pf (nT−T)} / T (Equation 5) Using Equations 1 to 5, the detected speed Vf (nT) and the actual speed V ( The difference from t) can be expressed as in Equation 6.

Vf (nT) −V (t) = − (A / 2) (T + 2Tl) (Equation 6) In other words, the detected speed Vf (nT) is (1) relative to the actual speed V (t). / 2) (T + 2 Tl) is delayed.

For example, at the time of latching after t = 2T, θ (3T-T
When l) = x _2, latched position x ₂ from 3T-Tl to 3T
Fixed to. That is, Pl (3T-Tl~ 3T) = x 2. Therefore, the speed control detection position Pf (3T) = x ₂ .
Similarly, at the time of latching after t = 3T, θ (4T−Tl) = x ₃
Then, the speed control detection position Pf (4T) = x ₃ . Therefore, the detection speed Vf (4T) = {Pf (3T) −Pf (4T)} / T =
(x ₃ −x ₂ ) / T. This detected speed Vf (4T) is the rotational speed V (4T- (1T) when delayed by (1/2) (T + 2Tl) from 4T.
/ 2) (T + 2 Tl)).

As described above, the reason why the detected speed Vf (nT) is delayed with respect to the actual speed V (t) is that the time Tl exists from the latch by the counter to the detection by the detection unit 220. And the detected speed Vf in a certain control cycle
This is because the latch position in the previous control cycle is used to calculate (nT).

Here, the time delay of the detected speed Vf (nT) with respect to the actual speed V (t) is Td1.

Next, as shown in FIG. 3, the speed control processing unit 240 uses the speed command and speed feedback (detected speed).
And the speed error is calculated (S20-3).

Next, the speed control processing unit 240 has a band elimination filter and takes out only the specific frequency component of the speed error or the speed command in which the speed error is adjusted. For example, the speed control processing unit 240 extracts the speed error in the low frequency range only or the speed command in which the speed error is adjusted by the low-pass filter (S20-4).

Further, the speed control processing unit 240 performs integral compensation (S20) in order to increase servo rigidity with respect to the speed error subjected to band elimination processing or the speed command in which the speed error is adjusted.
-5) is performed, proportional gain calculation (S20-6) is performed,
A current command is calculated (S20-7). Speed control processing unit 2
40 outputs a current command to the current amplifier 250, and then S3
0 to S50 are executed.

The speed control processing unit 240 performs software processing in order to perform the calculations from S20-1 to S20-7. It takes some time for the speed control processing unit 240 to perform software processing.

It also takes some time for the speed control processing unit 240 to supply the current to the servo motor 210 after outputting the current command.

Let Td2 be the sum of the software processing time by the speed control processing unit 240 and the time from when the speed control processing unit 240 outputs the current command until the current is supplied to the servomotor 210.

In the speed control system shown in FIGS. 1 to 3, the position of the servo motor 210 is detected, and the current corrected based on the detected position is used as the servo motor 21.
By the time it is supplied to 0, a dead time Td of Td1 + Td2 occurs.

In the past, the dead time was shortened as much as possible in order to stabilize the speed control system of the servo control device. When the dead time is lengthened, the phase delay of the output of the speed control processing unit 240 with respect to the input (hereinafter, simply referred to as the phase delay) increases. As a result, the gain in the speed control process at the resonance frequency is
This is because it is generally considered that the speed control system becomes unstable if the phase delay is 180 degrees or more when it is 0 dB or more, that is, when the resonance peak is 0 dB or more.

However, the present invention considers the stability of the entire industrial equipment as a series of control objects and servo control devices for controlling them. As a result, the phase delay is 18
Even if it is 0 degree or more, the phase delay of the speed control system is 180
It can be stabilized by being set so as to deviate sufficiently from the degree.

Thus, in order to widen the phase delay of the speed control system, the dead time Td should be set long, and
It may be considered to change the frequency of the first-order lag filter (for example, a low pass filter or a notch filter) provided in the speed control processing unit 240.

To set the dead time Td to be long, Td1
Alternatively, either one or both of Td2 may be lengthened. Prolonging the time delay Td1 can be achieved by prolonging the time Tl shown in FIG. 4, for example. Time delay Td
Lengthening 2 can be achieved, for example, by lengthening the software processing time by the speed control processing unit 240 shown in FIG.

The adjustment of the phase delay between the natural vibration wave to be controlled and the control cycle of the speed control process is performed for each industrial device. When the industrial equipment includes a plurality of control targets, it is preferable that the phase delay of each control target be adjusted. This is because each controlled object has its own unique frequency. This is because, for example, the natural frequency of the ball screw due to the axial rigidity and the natural frequency of the ball screw due to the torsional rigidity are different for each ball screw.

The dead time Td is set by first calculating the resonance frequency, then calculating the gain at the resonance frequency from the transfer function of the speed control system, and then determining the desired gain margin and phase margin of the resonance frequency. It is executed by setting the dead time Td so as to be obtained. Here, in order to confirm the stability of the speed control system, the cutoff frequency (hereinafter, also referred to as speed loop gain (unit is rad / sec or Hz)) is increased.

The speed loop gain can be maximized by repeating the setting of the dead time Td and the confirmation of the stability. Incidentally, in order to obtain the transfer function, a transfer function measuring function provided in an NC (Numerical Control) device generally provided in industrial equipment may be used. Further, an FFT (Fast Fourier Transform) measuring device may be used in order to obtain first-order, second-order, and third-order or higher phase delays of the resonance frequency.

The state of the industrial equipment when set by the industrial equipment control method according to the embodiment of the present invention and the effect of the present embodiment will be described below. 5 to 8 are examples in which the dead time Td is set longer by increasing the time Tl.

FIG. 5A shows a timing chart of the servo control device in the industrial equipment set by the conventional industrial equipment control method. FIG. 5B shows a timing chart of the servo control device in the industrial equipment set by the industrial equipment control method according to the embodiment of the present invention.

Both FIG. 5A and FIG. 5B show a central processing unit (CPU) provided in the speed control processing unit.
2 and a timing chart of the operation of the encoder of the detection unit provided in the servo motor. 5A and 5B show the operations of the CPU and the encoder from 0 to 3T for each control cycle T.

At t ₀ , the CPU sends a detection signal to the encoder (see arrow). Next, at ta, the encoder latches the position of the servomotor 210. Next, at tb, the encoder sends the servo motor 21 to the CPU.
Send 0 position feedback. Next, at tc, the CPU performs processing for calculating velocity feedback based on position feedback. Since tc starts at the beginning of each control cycle, tc and nT (n is an integer)
Overlaps with. Next, at td, the CPU outputs the current command corrected based on the speed feedback and the speed command, and the current based on the current command is supplied to the servo motor 210.

Therefore, the dead time Td is the time from ta to td.

Here, comparing FIG. 5 (A) and FIG. 5 (B), in FIG. 5 (B), the latch timings t ₀ and ta are set earlier than in FIG. 5 (A). There is.
Therefore, it can be seen that the dead time is longer in FIG. 5B than in FIG.

FIG. 6A shows a Bode diagram of the servo control device in the industrial equipment set by the conventional industrial equipment control method. FIG. 6B shows a Bode diagram of the servo control device in the industrial equipment set by the industrial equipment control method according to the embodiment of the present invention.

FIGS. 6A and 6B correspond to Bode diagrams of the servo controller according to the timing charts shown in FIGS. 5A and 5B, respectively.

The gain of the servo control device at the resonance peak can be obtained from the graphs showing the gain characteristics in FIGS. 6A and 6B. Further, the phase characteristics of the speed control system can be obtained from the graphs showing the phase characteristics in FIGS. 6 (A) and 6 (B). The horizontal axis of the graph showing the gain characteristic shows the frequency, and the vertical axis thereof shows the gain characteristic. The horizontal axis of the graph showing the phase characteristics shows the frequency, and the vertical axis thereof shows the phase characteristics.

A resonance peak due to the torsional rigidity of the ball screw occurs near 400 Hz. In FIG. 6, these resonance peaks are indicated by arrows.

Comparing FIG. 6 (A) and FIG. 6 (B),
It can be seen that the phase delay in FIG. 6 (B) deviates from 180 degrees than in FIG. 6 (A). Therefore, while the industrial equipment having the characteristics shown in FIGS. 6 (A) and 5 (A) is unstable, the industrial equipment having the characteristics shown in FIGS. 6 (B) and 5 (B) is stable. It turns out that That is, the phase characteristic is-(180 + 360 * n) degrees (n
Is an integer greater than or equal to 0), and industrial equipment is stabilized by setting it so as to be sufficiently deviated.

FIGS. 7A and 7B show Nyquist diagrams of industrial equipment corresponding to the Bode diagrams shown in FIGS. 6A and 6B, respectively. From FIGS. 7 (A) and 7 (B), it is clear that the industrial equipment having the characteristics shown in FIG. 6 (B) is more stable than the industrial equipment having the characteristics shown in FIG. 6 (A). become.

Generally, in the Nyquist diagram, if the value is less than −1 when passing through the horizontal axis, the system is unstable,
If it is larger than -1, it can be judged to be stable.

When the curve passes through the horizontal axis X of the graphs shown in FIGS. 7 (A) and 7 (B), the curve in FIG. 7 (A) passes through a point less than X = −1. In 7 (B) the curve is
Pass points greater than X = −1. Therefore, the industrial equipment having the characteristics shown in FIG.
Industrial equipment having the characteristics shown in (B) is stable.
Therefore, the industrial equipment having the characteristics shown in FIGS. 5 (B) and 6 (B) is more stable than the industrial equipment having the characteristics shown in FIGS. 5 (A) and 6 (A). It is clear that there is.

FIG. 8 shows the circular interpolation accuracy of the speed control system shown in FIGS. 5 (A) and 5 (B). Here, the reference circle is a circle passing through the center of each scale shown in FIG.
In the present embodiment, when the dead time is short, the stability is not good, and therefore the speed cutoff frequency, that is, the speed loop gain (speed responsiveness) cannot be increased.
Therefore, as shown in FIG. 8, when the dead time is short, the roundness is poor. When the dead time is long, the stability is improved, and the speed cutoff frequency, that is, the speed loop gain (speed responsiveness) can be increased. Therefore,
As shown in FIG. 8, when the dead time is long, the roundness is improved. As described above, according to the present embodiment, the phase characteristic of the speed control system at the resonance peak is-(180 + 360 * n) degrees (where n is (Integer of 0 or more). Therefore, the speed control system of the servo controller can be stabilized. Thereby, the industrial equipment having such a servo control device is stabilized.

Further, since the industrial equipment control method according to the present embodiment can be applied to each industrial equipment and each control target, different settings can be made according to individual differences between the industrial equipment and the control target. Can be applied. As a result, the industrial device control method according to the present embodiment can stabilize all industrial devices and control targets.

[0077]

INDUSTRIAL APPLICABILITY The industrial equipment control method and the industrial equipment according to the present invention can improve the stability of the speed control system without depending only on the reduction of the gain characteristic.

Further, the industrial equipment control method and the industrial equipment according to the present invention can improve the stability of the speed control system even when there are a plurality of resonance peaks.

[Brief description of drawings]

FIG. 1 is a schematic block diagram of industrial equipment according to an embodiment of the present invention.

FIG. 2 is a flow chart briefly showing the operation of the industrial equipment according to the present embodiment.

FIG. 3 shows a speed control processing unit 240 in S20 of FIG.
FIG. 6 is a flowchart showing the operation of the speed control processing unit executed by the above.

FIG. 4 is a diagram showing a timing chart from detection of the position of the servo motor 210 to calculation of speed feedback.

FIG. 5 is a diagram showing a timing chart of a servo control device in an industrial device.

FIG. 6 is a Bode diagram of a servo control device in industrial equipment.

7 is a Nyquist diagram of industrial equipment corresponding to the Bode diagram shown in FIG. 6;

FIG. 8 is a diagram showing arc interpolation accuracy of the speed control system shown in FIGS. 5 (A) and 5 (B).

[Explanation of symbols]

100 controlled objects 110 table 120 ball screw 200 speed control system 210 servo motor 220 detector 230 Speed command generator 240 Speed control processing unit 250 current amplifier

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 3C001 KA07 TA05 TB01 TB06                 5H303 AA01 AA10 BB01 CC03 DD01                       EE03 FF03 GG11 HH05 JJ01                       KK02 KK03 KK17

Claims (11)

[Claims] 1. A drive unit for driving a control target; a detection unit for detecting positional information of at least one of the control target and the drive unit; and an operation of at least one of the control target and the drive unit. A speed command generation unit that outputs a speed command that defines the speed, the position information is input from the detection unit, the speed command is input from the speed command generation unit, and based on the position information and the speed command. In an industrial device including a control processing unit that outputs a current command to the drive unit and controls the drive unit, an input / output phase of the control processing unit at a resonance frequency resulting from a natural frequency of the control target. A method for controlling industrial equipment, characterized in that characteristics are set for each of the industrial equipment. 2. The phase characteristic of input and output of the control processing unit at the resonance frequency is set so as to be shifted from − (180 + 360 * n) degrees (n is an integer of 0 or more). Industrial equipment control method. 3. The industrial equipment control method according to claim 1, wherein a phase delay of input and output of the control processing unit at the resonance frequency is set to be larger than 180 degrees. 4. A delay based on a period of the control cycle and a difference between a detected speed of the control target or the drive unit calculated based on the position information and an actual speed of the control target or the drive unit. The industrial equipment control method according to any one of claims 1 to 3, wherein the phase delay is set by increasing a dead time including time. 5. A pass frequency of a band pass filter that passes a specific frequency range of a difference between the detected speed of the controlled object or the drive unit calculated based on the position information and the speed command, or the position. The phase delay is set by changing the removal frequency of a band elimination filter that eliminates a specific frequency band in the difference between the detected speed of the controlled object or the drive unit calculated based on information and the speed command. The industrial equipment control method according to any one of claims 1 to 3, characterized in that. 6. A drive unit for driving a controlled object, a detection unit for detecting positional information of at least one of the controlled object or the driving unit, and an operation of at least one of the controlled object or the driving unit. A speed command generation unit that outputs a speed command that defines the speed, the position information is input from the detection unit, the speed command is input from the speed command generation unit, and based on the position information and the speed command. A control processing unit for controlling the drive unit by outputting a current command to the drive unit, and the input / output phase characteristic of the control processing unit at a resonance frequency resulting from the natural frequency of the control target Industrial equipment set for each equipment. 7. The input / output phase characteristic of the control processing unit at the resonance frequency is set to be shifted from − (180 + 360 * n) degrees (n is an integer of 0 or more). Industrial equipment described in. 8. The industrial equipment according to claim 6, wherein a phase delay of input and output of the control processing unit at the resonance frequency is set to be larger than 180 degrees. 9. A delay based on a period of the control cycle and a difference between a detected speed of the control target or the drive unit calculated based on the position information and an actual speed of the control target or the drive unit. The industrial equipment according to any one of claims 6 to 8, wherein the phase delay is set by increasing a dead time including time. 10. The bandpass filter that passes a specific frequency range of a difference between the detected speed of the controlled object or the drive unit calculated based on the position information and the speed command, or , A band removal filter for removing a specific frequency band in the difference between the detected speed of the controlled object or the drive unit calculated based on the position information and the speed command, the pass frequency of the band pass filter or 9. The industrial equipment according to claim 6, wherein the phase delay is set by changing a removal frequency of the band elimination filter. 11. The control target is a drive mechanism, the natural frequency of the control target is a frequency caused by the rigidity of the drive mechanism, and the position information is the position of the drive mechanism or the drive unit. The industrial device according to any one of claims 6 to 10, wherein the industrial device is in a rotating position.