JP2002287831A - Resonance restraining device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a device capable of restraining resonance by adaptively making the autonomous change of center frequency of a notch filter for every product regarding a resonance restraining device for restraining resonance generated to a control object, using the notch filter. SOLUTION: Weighting processing parts 12, 13 weight both narrow bands of a high frequency region and a low frequency region near the set center frequency of an adaptive notch filter 3 of a position error signal 5 received in a signal receiving part 11, with a prescribed function W. Dispersion value computing parts 14, 15 compute dispersion values σl , σh on the output. A parameter estimating part 16 compares the dispersion values σl , σh and sets the set center frequency of the adaptive notch filter 3, shifting it toward the larger dispersion value and gives the set value to the adaptive notch filter 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to control of an object to be controlled, and more particularly to resonance using a notch filter suitable for resonance control of a magnetic disk drive or a positioning control system for moving a head to a specific position in an optical disk drive. It relates to a suppression device.

[0002]

2. Description of the Related Art For example, in a head positioning control device of a magnetic disk drive, a head is moved in a radial direction of the disk to seek a target position of a rotating disk (magnetic disk). The head is moved by the VC provided at the base of the arm.
Since this is performed by swinging the arm by M (voice coil motor), resonance occurs in the arm and bearing of the head positioning control device. For example, the arm and the VCM have large and small resonance modes in a frequency band of about 3 kHz or more. This resonance mode not only adversely affects the positioning accuracy, but also causes a seek residual vibration, and in the worst case, also causes the operation of the head positioning control device to become unstable. Therefore, conventionally, in order to remove the resonance mode, the required number of notch filters for the frequency where the resonance mode exists are inserted into the control loop.

[0003] The resonance mode varies from solid to solid for each product, and further varies depending on the environment such as temperature and aging. Therefore, with a fixed notch filter with uniquely determined constant parameters, if the set frequency deviates from the frequency at which the resonance mode actually exists, the operation becomes unstable or oscillates. On the contrary, there is a possibility that the problem of deteriorating the accuracy of the positioning control may occur.

Therefore, as a means for automatically adjusting the notch filter for each product, a test signal is externally applied to a head positioning control system, and the mechanical compliance characteristics of the product are measured. First, the parameters of the notch filter are determined.

[0005]

However, while a test signal is being applied from the outside, the original purpose of the product cannot be achieved. For example, in the case of a magnetic disk drive, data cannot be read from or written to a disk or moved to a target track while a test signal is being applied. Therefore, the method of adjusting the notch filter using an external test signal can be performed only when a new calibration time is provided, or only when the device is shipped from the factory or when the power is turned on.

In view of the above problems, the present invention estimates, for each product, a parameter of a notch filter for suppressing resonance on a DSP (digital signal processor) of the product and sets a notch filter for compensating a resonance point. An object of the present invention is to provide a resonance suppression device that suppresses resonance by adaptively changing the center frequency autonomously.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a notch filter suitable for suppressing resonance such as a head positioning control system of a magnetic disk drive, which automatically controls only a set center frequency of the notch filter. In order to suppress resonance, the following means are provided.

According to the present invention, there is provided a signal receiving means for receiving either an output signal of a controlled object or an input signal to the controlled object, and a high-frequency signal near a predetermined center frequency of the notch filter for the received signal. Weighting means for weighting the narrow band on the frequency side (slightly high area) or the narrow band on the low frequency area (slightly low area); and a weighting means for each of the weighted narrow bands on the high frequency side or the low frequency side. A variance value calculating means for calculating a variance value, comparing the variance value on the high frequency range side with the variance value on the low frequency range side, and when the high frequency range side variance value is large, the center of the notch filter is A parameter that is set by shifting the frequency to the high frequency side, or by shifting the center frequency of the notch filter to the low frequency side when the low frequency side dispersion value is large. Characterized in that it comprises a chromatography data estimating means.

Further, the weighting processing means of the present invention performs weighting such that one of the weighting functions or the weighting value for the narrow band on the high frequency side or the narrow band on the low frequency side becomes larger than the other. It is characterized by the following.

Further, the parameter estimating means of the present invention is characterized in that the center frequency of the notch filter is shifted by a predetermined unit frequency toward a high frequency side or a low frequency side.

Further, when a plurality of notch filters are provided, the parameter estimating means of the present invention is characterized in that the center frequency of each of the notch filters is set so as to maintain a predetermined band interval.

Further, when there is a peak of a frequency unrelated to resonance in a corresponding frequency band of the notch filter, the variance value calculating means of the present invention weights the weight using a weight function in which the inverse characteristic of the peak is set in advance. Is performed.

The present invention operates as follows. According to the present invention, an instruction current signal to an actuator such as a VMC to be controlled is received by a signal receiving unit, and a weighting processing unit receives a command current signal on a high frequency range near a set center frequency of the notch filter. The narrow band and the narrow band on the low frequency side are weighted, and the variance calculating means calculates the variance of the weighted current values of the narrow bands on both sides. Next, the variance value in the high frequency range and the variance value in the low frequency range are compared by the parameter estimating means, and it can be estimated that the resonance point exists in the larger variance value. The set center frequency is set by shifting the variance value by a predetermined unit to the larger one. By repeating the above processing a plurality of times, the set center frequency of the notch filter is optimally set. The signal receiving means may use a position error signal output by the actuator instead of the instruction signal current to the actuator.

As described above, according to the present invention, the variance of the narrow band current value on both sides near the set center frequency of the notch filter is obtained, the frequency having a large variance value is set as the resonance frequency, and the notch is set so as to minimize the variance. Set the filter.

This makes it possible to autonomously adjust the notch filter for suppressing the resonance with high precision for each product without having to consider in advance a very wide range of variation and fluctuation of the resonance. In addition, since it is not necessary to apply an external test signal to adjust the notch filter, and the adjustment can be performed during the normal following control, the notch filter adaptive operation for suppressing the resonance can be performed even during operation.

[0016]

Embodiments of the present invention will be described below.

[First Embodiment] FIG. 1 shows a head positioning control system of a magnetic disk drive as a control system to which the present invention is applied. As shown in FIG. 1, the head positioning control system includes an actuator 2 to be controlled and a feedback controller 4 for controlling feedback of a position error signal 5 from the actuator 2. The resonance suppression device according to the present invention includes an automatic notch filter 3 for suppressing resonance of an automatic resonance parameter adjuster 1 and an actuator 2.

The automatic resonance parameter adjuster 1 includes a signal receiving unit 11, weighting processing units 12 and 13, and a variance value calculating unit 1.
4 and 15 and a parameter estimating unit 16.

The signal receiving section 11 is means for receiving the position error signal 5 which is the output of the actuator 2 or the instruction current signal 6 which is the input.

The weighting processing section 12 is a means for applying a weighting function W _l is the transfer function to the narrowband low frequency range side in the vicinity of the set central frequency f _r of the adaptive notch filter 3. Weighting processing unit 13, likewise, is a means for applying a high frequency range side of the narrow band to the weight function W _h in the vicinity of the set central frequency f _r of the adaptive notch filter 3. Weight function W
subscripts l and h of _l and W _h shows an or lower than the set center frequency f _r of the current adaptive notch filter 3 (low) frequency domain is higher (high) frequency domain.

The variance value calculation unit 14 includes the weighting processing unit 12
A means for calculating a variance value sigma _l of frequency for the narrowband low frequency range side of the set central frequency f _r of the adaptive notch filter 3 weighted by. The variance value calculation unit 15
Similarly, the means to calculate the variance sigma _h of frequency for the high frequency range side of the narrow band of the set central frequency f _r of which is weighted by the weighting processing unit 13 adaptive notch filter 3.

The parameter estimation unit 16 compares the variance value sigma _l and variance sigma _h, a means for moving the set center frequency f _r of Δf by the adaptive notch filter 3 in high dispersion value direction.

The operation of the present invention will be described below.

[0024] The weighting processing unit 12, 13, respectively, by using a weighting function W _l and W _h, performs weighting in the frequency domain on both sides of the set central frequency f _r of the adaptive notch filter 3, the variance value calculator 14 , 15 respectively, the weight functions W _l and W
from the output of _h, obtaining the variance sigma _l and sigma _h in the frequency region near both sides of the set central frequency f _r of the adaptive notch filter 3 that is currently set. For applying a two weight functions W _l and W _h into the same signal from the signal receiving unit 11, always variance sigma _l on either side of the set central frequency f _r
And the variance σ _h can be obtained.

In this example, the weight functions _Wl and _Wh are shown in FIG.
The transfer function is as shown in FIG. Specifically, it is a second-order transfer function represented by the following equation (1).

[0026]

(Equation 1)

FIG. 3 shows an example of the current spectrum of the present control system. Here, the actual resonance frequency is 4 kHz to 6
Because of the order of kHz, the setting range of the set central frequency f _r of the adaptive notch filter 3 is also to be limited to this range. As shown in Fig. 3, the unevenness on the frequency axis of the current in the same region is
Adaptive notch filter 3 (5.2kHz and 6.1kHz
) Except for 5 dB.

If the variance values σ _l and σ _h are obtained, it can be estimated that the resonance point exists at the higher variance value (this estimation is correct). _It is sufficient to move _r by Δf to the higher variance value. Here, Δf is 250 Hz.

The logic of the parameter estimating unit 16 is as follows.

[0030]

(Equation 2)

Find <> in equation (2) is -1 when the result of division of the first and second terms is greater than or equal to the third term λ, +1 when the result is less than 1 / λ, and +1 for other results. Sometimes it means returning 0. Since the spectrum of the current is not white, an error is added to that extent, so the design parameter λ is introduced in consideration of the absolute value of the dispersion. By introducing such a threshold value, it is possible to absorb unevenness of the dispersion value on the frequency axis due to factors unrelated to the resonance point. Here, the variance multiplied by the weight function shown in FIG.
Since the average is considered to be smaller, the design parameter λ is set to 2.

The weight function W_lAnd W_hBut adaptation
Center frequency f of switch filter 3 _rFunction
Is the center frequency f set by the adaptive notch filter 3._rTo
Therefore, the weight function W_lAnd W_hAlso shifts on the frequency axis
It means you have to go. This is the signal
The same signal from the receiver 11 is assigned a weight function W_lAnd W _h
Can be achieved.

FIG. 4 is a diagram for explaining the flow of processing according to the present invention.

In the resonance parameter automatic adjuster 1, the signal receiving section 11 receives the instruction current signal 6 or the position error signal 5 (step S1). Weighting processing units 12 and 13
In the adaptive notch filter 3 set the center frequency f _r performs high frequencies and weighting narrowband low frequency range side in the vicinity of (step S2), and the variance calculation unit 15, weighting processing unit 12, 13 each variance sigma _l on the basis of the output, the sigma _h determined in (step S3), and the parameter estimation unit 16 compares the variance value sigma _l, sigma _h (step S4). Variance sigma _l is large when (the low frequency band side is large) (step S5), and sets shifting the set center frequency f _r of the current adaptive notch filter 3 to the unit component (250 Hz) lower frequency band side (step S6), variance value σ
If _h is larger (higher frequency band side is large) (step S5), and sets shifting the set center frequency f _r of the current adaptive notch filter 3 to the unit component (250 Hz) the high frequency range side (step S7), and If not, the process ends. [Second Embodiment] When there are a plurality of resonance points, each of the adaptive notch filters 3 is usually provided, and the above-described processing is performed for each resonance point to suppress resonance. In this case, the resonance parameter automatic adjuster 1 shown in FIG.
Is provided for each adaptive notch filter 3.

However, when a plurality of resonance points (resonance peaks) exist, the adaptive notch filter 3 is set to the average value of the two frequency-weighted variances. When a plurality of resonance peaks exist in a frequency band close to each other, even if the adaptive notch filter 3 is inserted into each resonance peak, there may be a case where the adaptive notch filter 3 cannot be sufficiently adapted.

FIG. 5 shows a state in which the adaptation of the adaptive notch filter 3 to the two resonance peaks has failed. In this case, at least two or more adaptive notch filters 3, which are the number of resonance peaks, must be set in a corresponding frequency region. However, even if the same number as the resonance peaks, that is, two adaptive notch filters 3 are inserted, the two resonance peaks are close to each other, so that both are set to the frequency indicated by the dotted line in FIG. there is a possibility.

On the other hand, for the adaptive notch filter 3 for each resonance peak, the weighting processing unit 12
13 can be avoided by using different characteristics for the weighting function used in each of the sub-bands 13, that is, different characteristics in the low frequency band and the high frequency band.

In the second embodiment, the weighting processing units 12, 1 of the automatic resonance parameter adjuster 1 shown in FIG.
3, the weighting function or weighting value for the narrow band on the high frequency side or the narrow band on the low frequency side is
Weighting is performed so that one is greater than the other.

For example, of the two adaptive notch filters 3, the adaptive notch filter 3 for the resonance peak on the low frequency band side has different characteristics of the weight function used in the weighting processing unit 12, as shown in FIG. As shown in FIG. 7, the characteristic of the weighting function used in the weighting processing unit 13 for the adaptive notch filter 3 for the resonance peak in the high frequency range By changing, the weight on the high frequency side is increased. In this way, by assigning different weighting patterns to the adaptive notch filters 3 adjacent to each other, roles on the frequency axis are assigned.

[Third Embodiment] When there are three or more resonance peaks, the role of the adaptive notch filter 3 on the frequency axis as described in the second embodiment does not hold. There is. In this case, by setting the center frequency f _r of each of the adaptive notch filter 3 applies certain restrictions so as not too close to each other, setting of the adaptive notch filter 3 for different resonance peak center frequency f _r
Are set to the same frequency.

In the third embodiment, the parameter estimator 16 of the automatic resonance parameter adjuster 1 shown in FIG.
, The setting of each of the adaptive notch filter 3 the center frequency f _r
Setting the center frequency f _r but to hold a predetermined band interval
Set. For example, as shown in FIG. 8, in the case of setting the center frequency f _r1, f _r2, f _r3 three adaptive notch filter 3, these set central frequency f _r1, f _r2, f _r3 is,
If they are set to be at least apart from each other by the frequency bandwidth d, the set center frequencies _fr1 , _fr2 , _{fr3 of} all the adaptive notch filters 3 will not be set to the same frequency. Therefore, even if the set center frequency _fr1 of one adaptive notch filter 3 is set to the average value of the variance, it is not set to the set center frequency _fr2 which is the average value of the other adaptive notch filters 3. , It will always settle down where the resonance peak is canceled.

[Fourth Embodiment] When a peak not due to resonance exists in the vicinity of a resonance peak in a measurement signal input to the resonance parameter automatic adjuster 1, there is a possibility that the determination of the resonance peak may be erroneous. is there. This is because the control target may have a specific spectrum characteristic depending on the manufacturing environment. In this case, the above-mentioned algorithm of the adaptive notch filter 3 cannot cope. In the first embodiment, it has already been described that the parameter λ used in the parameter estimating unit 16 absorbs the frequency unevenness of the signal. However, as another method, the characteristics of the weighting function are devised.

That is, in the fourth embodiment, the average (several units and several heads) of the power spectrum of the signal in the corresponding frequency region of the adaptive notch filter 3 is measured in advance, and as shown in FIG. Weighting processing units 12 and 13
Is to use a what had previously been moistened with inverse characteristics r of the spectrum to the weight function W _l and W _h. This method is difficult to deal with when the signal spectrum varies, but if there is no extreme variation, it can be almost completely covered by setting the parameter λ and setting the inverse characteristic of the spectrum. Conceivable. Note that the inverse characteristic r of the power spectrum of this signal may be applied to the signal receiving unit 11.

Although the present invention has been described with reference to the embodiments, the present invention can be variously modified within the scope of the gist. For example, the above-described embodiments of the present invention can be implemented individually, or can be implemented by appropriately combining some of them. [Specific Example] In order to clarify the effect of the present invention, the following simulation evaluation was performed as a specific example. As a control system implemented in the specific example, a control system using a feedback controller 4 designed based on modern control theory was used. The simulation was performed for 2 seconds, and the resonance frequency of the primary mode was changed from 4.5kHz to 4.9kHz to
The behavior of the adaptive notch filter 3 when changing to 5.3 kHz was evaluated. Set center frequency f of adaptive notch filter 3
The initial value of _r is 4.5 kHz. The sampling frequency of the input position error signal 5 was 10 kHz. At this time, the plant characteristics changed over time as shown in FIG.

First, the result when there is no adaptive notch filter 3 according to the present invention will be described. FIG. 11 is a diagram illustrating a change in open-loop characteristics when a fixed notch filter having a set center frequency of 4.5 kHz is applied. In FIG. 11, the solid line shows the open-loop characteristic when the resonance frequency is 4.5 kHz (initial state), and the dotted line shows the open-loop characteristic when the resonance frequency is 5.3 kHz (final state). Resonance frequency from 4.5kHz to 5.
It can be seen that as the frequency shifts to 3 kHz, the secondary stability margin (the stability margin at the second zero crossing) decreases, that is, the open-loop gain increases due to the resonance peak. The position error power spectrum at this time is shown in FIGS. FIG. 12 shows the spectrum in the initial state (the resonance frequency is 4.5 kHz), and FIG. 13 shows the spectrum in the final state (the resonance frequency is 5.3 kHz). As shown in FIG. 12, it is normal in the initial state, but the resonance frequency fluctuates with time, and as shown in FIG. 13, it can be seen that the position error near the resonance frequency increases in the final state. .

On the other hand, FIG. 14 shows the variation of the open loop characteristic when the present invention is applied. In FIG. 14, the dotted line shows the open loop characteristics in the initial state (resonance frequency is 4.5 kHz), and the solid line shows the open loop characteristics in the final state (resonance frequency is 5.3 kHz). Since the adaptive notch filter 3 follows the resonance point, the present invention is not applied (FIG. 1).
It can be seen that the increase in gain has been eliminated as compared with the case of FIG.

FIGS. 15 and 16 show the power spectrum of the position error signal 5 when the adaptive notch filter 3 according to the present invention is applied. The power spectrum shown in FIG. 15 is almost the same as that shown in FIG.
It can be seen that in the final state shown in FIG. 16, the position error at the resonance frequency is less deteriorated than in the final state shown in FIG. 13 where the present invention is not applied. The reason that the position error due to resonance does not seem to be completely eliminated is that the disturbance model is not changed in the simulation in accordance with the adaptive operation of the adaptive notch filter 3 first.
The reason is that the time signal itself used for displaying the spectrum by T fluctuates due to the adaptive operation of the adaptive notch filter 3 over time and becomes inaccurate, and the like.

[0048] Figure 17 shows the time course of the estimation result of setting the center frequency f _r of the adaptive notch filter 3. The switching points of the resonance frequency are 0.67 seconds and 1.33 seconds. Although there is a slight time lag in tracking the resonance point of the adaptive notch filter 3, it can be seen that the resonance frequency accurately follows the change of the resonance frequency from 4.5 kHz to 4.9 kHz to 5.3 kHz.

The features of the embodiments and examples of the present invention are listed below.

(Supplementary Note 1) A resonance suppressing device that suppresses resonance generated in a control target using a notch filter, and a signal receiving unit that receives one of an output signal of the control target and an input signal to the control target. Weighting processing means for weighting a predetermined narrow band on the high frequency side or low frequency side near the preset center frequency of the notch filter for the received signal; and the weighted high frequency side or low frequency side. A variance value calculating means for calculating a variance value of each of the narrow bands on the frequency band side, and a variance value on the high frequency band side and a variance value on the low frequency band side, wherein the variance value on the high frequency band side is If the value is large, the center frequency of the notch filter is shifted to the high frequency side, or if the low frequency side dispersion value is large, the center frequency of the notch filter is set. A resonance estimating device comprising: parameter estimating means for setting a frequency shifted to a lower frequency side. (Supplementary Note 2) In the resonance suppression device according to Supplementary Note 1, when a plurality of notch filters are provided, the weighting processing unit performs weighting so that the weighting patterns of the adjacent notch filters are different from each other. A resonance suppression device characterized by the above-mentioned. (Supplementary Note 3) In the resonance suppression device according to Supplementary Note 1, the parameter estimating unit shifts a center frequency of the notch filter by a predetermined unit frequency toward a high frequency side or a low frequency side and sets the center frequency. Resonance suppression device. (Supplementary Note 4) In the resonance suppression device according to Supplementary Note 1, when the parameter estimating unit includes a plurality of notch filters, the parameter estimating unit sets the center frequency of each of the notch filters so as to maintain a predetermined band interval. Characteristic resonance suppression device. (Supplementary Note 5) In the resonance suppression device according to Supplementary Note 1, the dispersion value calculating unit may determine whether a peak of a frequency unrelated to resonance exists in a corresponding frequency band of the notch filter.
A resonance suppression apparatus characterized in that weighting is performed using a weight function in which the inverse characteristic of the peak is set in advance. (Supplementary Note 6) A resonance suppression method for suppressing resonance generated in a control target using a notch filter, the signal reception processing step of receiving one of an output signal of the control target and an input signal to the control target, A weighting process of weighting the received signal to a predetermined narrow band on the high frequency side or low frequency side near the preset center frequency of the notch filter; and the weighted high frequency side or low frequency. A variance value calculating step of calculating each variance value of a narrow band on the band side, and comparing the variance value on the high frequency band side and the variance value on the low frequency band side, and the variance value on the high frequency band side is large. In this case, the center frequency of the notch filter is shifted to the high frequency side, or the center frequency of the notch filter is set when the low frequency side dispersion is large. A parameter estimating process of setting the number by shifting to a lower frequency side.

(Supplementary Note 7) In the resonance suppressing method according to Supplementary Note 6, in the weighting process, one of the weighting function or the weighting value for the narrow band on the high frequency band side or the narrow band on the low frequency band side is one. A resonance suppression method characterized by performing weighting so as to be larger than the other.

(Supplementary Note 8) In the resonance suppression method according to Supplementary Note 6, in the parameter estimating process, the center frequency of the notch filter is shifted by a predetermined unit frequency toward the high frequency range or the low frequency range. A resonance suppression method characterized by the above-mentioned.

(Supplementary note 9) In the resonance suppression method according to supplementary note 6, in the parameter estimation processing step, when a plurality of notch filters are provided, the center frequency of each of the notch filters is set to maintain a predetermined band interval. A resonance suppressing method characterized by setting.

(Supplementary note 10) In the resonance suppression method according to Supplementary note 6, in the dispersion value calculating step, when a peak of a frequency unrelated to resonance exists in a corresponding frequency band of the notch filter, an inverse characteristic of the peak is determined in advance. A weighting method is performed using a weighting function that sets the following.

[0055]

As described above, according to the present invention, it is not necessary to apply an external test signal to adjust the notch filter for suppressing the resonance, and the adaptive operation of the notch filter can be executed even during the ordinary following control. Therefore, it is possible to autonomously adjust a notch filter for resonance control with high accuracy for each product without having to consider in advance a very wide range of variation and fluctuation of resonance. As a result, not only can the accuracy of the arm positioning control be improved, but also manual fine tuning for each product can be eliminated.

Further, the minimum configuration of the present invention only requires mounting a second-order filter as a frequency weighting function and requires only several tens of words in terms of code size (however, the adaptive notch filter and the weighting function require (Except for the parameter table), can be easily realized.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is a diagram illustrating an example of a weight function according to the first embodiment.

FIG. 3 is a diagram illustrating an example of a current spectrum.

FIG. 4 is a diagram showing a processing flow of the present invention in the first embodiment.

FIG. 5 is a diagram illustrating an example of a state where application of an adaptive notch filter has failed in the second embodiment.

FIG. 6 is a diagram illustrating an example of a weight function for an adaptive notch filter with respect to a resonance point on a low frequency band side according to the second embodiment.

FIG. 7 is a diagram illustrating an example of a weight function for an adaptive notch filter with respect to a resonance point on a high frequency band side according to the second embodiment.

FIG. 8 is a diagram illustrating a setting example of an interval between set center frequencies of a plurality of adaptive notch filters according to the third embodiment.

FIG. 9 is a diagram illustrating an example of a weighting function including an inverse characteristic of a signal spectrum according to the fourth embodiment.

FIG. 10 is a diagram showing an example of a change over time in plant characteristics in the example.

FIG. 11 does not apply the present invention (fixed notch filter 4.
FIG. 9 is a diagram illustrating an example of a change in open-loop characteristics when 5 kHz is applied).

FIG. 12 is an initial state (4.5 kHz) when the present invention is not applied;
It is a figure showing an example of a position error power spectrum in z).

FIG. 13 shows a final state (5.3 kHz) when the present invention is not applied.
It is a figure showing an example of a position error power spectrum in z).

FIG. 14 is a diagram illustrating an example of a change in open-loop characteristics when the present invention is applied.

FIG. 15 is an initial state when the present invention is applied (4.5 kHz);
FIG. 7 is a diagram showing an example of a position error power spectrum at the time of FIG.

FIG. 16 shows a final state when the present invention is applied (5.3 kHz).
FIG. 7 is a diagram showing an example of a position error power spectrum at the time of FIG.

FIG. 17 is a diagram showing a temporal change in the estimation result of the set center frequency of the adaptive notch filter in the embodiment.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 resonance parameter automatic adjuster 11 signal receiving unit 12, 13 weighting processing unit 14, 15 variance value calculating unit 16 parameter estimating unit 2 actuator 3 adaptive notch filter 4 feedback controller 5 position error signal 6 instruction current signal

Claims (5)

[Claims] 1. A resonance suppression device that suppresses resonance generated in a control target using a notch filter, wherein the signal reception unit receives one of an output signal of the control target and an input signal to the control target. Weighting means for weighting a predetermined narrow band on the high frequency side or low frequency side near the preset center frequency of the notch filter for the received signal; and the weighted high frequency side or low frequency range Variance value calculation means for calculating the variance value of each of the narrow bands on the side, and comparing the variance value on the high frequency band side with the variance value on the low frequency band side. The center frequency of the notch filter is shifted to the high frequency side, or the center frequency of the notch filter is set low when the low frequency side dispersion is large. A resonance estimating device comprising: a parameter estimating unit configured to shift to a frequency range side. 2. The resonance suppressing device according to claim 1, wherein
The resonance suppression device according to claim 1, wherein the weighting processing means, when a plurality of notch filters are provided, performs weighting so that the weighting patterns of the adjacent notch filters are different from each other. 3. The resonance suppressing apparatus according to claim 1, wherein
The resonance suppressing apparatus according to claim 1, wherein said parameter estimating means shifts a center frequency of said notch filter by a predetermined unit frequency toward a high frequency side or a low frequency side. 4. The resonance suppressing device according to claim 1,
The resonance suppression apparatus according to claim 1, wherein the parameter estimating means sets a center frequency of each of the notch filters so as to maintain a predetermined band interval when a plurality of notch filters are provided. 5. The resonance suppressing device according to claim 1, wherein
The variance value calculation means performs weighting using a weight function in which an inverse characteristic of the peak is set in advance when a peak having a frequency unrelated to resonance exists in a corresponding frequency band of the notch filter. Resonance suppression device.