JPH10274238A - Magnetic bearing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To always reduce the influence of a changed disturbance frequency by estimating the frequency of a cyclical disturbance from the driving current of an electromagnet, outputting a disturbance suppressing signal for suppressing this cyclical disturbance, adding this signal to a positional signal and supplying it as an electromagnet control signal to a power amplifier. SOLUTION: In a disturbance suppression control device 9X, the frequency of a cyclical disturbance is estimated from driving currents Icxa and Icxb, disturbance suppressing signals Vrxa and Vrxb for suppressing this cyclical disturbance are outputted, the disturbance suppressing signals Vrxa and Vrxb are added to position control signals Vcxa' and Vcxb' by adders 10xa and 10xb, and these are supplied as electromagnet control signals Vcxa and Vcxb to power simplifiers 6xa and 6xb. Thus, since the driving current Icxa and Icxb of electromagnets 2xa and 2xb are controlled, even if a disturbance frequency is changed, its influence is always reduced. Therefore, in any rotational number regions, the vibration of a rotary body 1 caused by disturbance is suppressed, stable control is performed and high-speed rotation is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a magnetic bearing device.

[0002]

2. Description of the Related Art As a high-speed rotating machine such as a spindle device for a machine tool using a magnetic bearing device, two portions in the axial direction (axial direction) of a rotating body such as a main shaft are radially (radially) oriented by a radial magnetic bearing device. And an axial magnetic bearing device, which is non-contact supported at one location in the axial direction, is known.

FIGS. 1 and 2 show an example of a radial magnetic bearing device used in a high-speed rotating machine as described above. FIG. 1 is a cross-sectional view of a mechanical part of the radial magnetic bearing device, and FIG. 2 is a block diagram of a control part thereof. In addition,
In the following description, the axis in the axial direction is defined as the Z axis, and two radial axes orthogonal to the Z axis and orthogonal to each other are defined as the X axis and the Y axis. Although the radial magnetic bearing device supports one portion of the rotating body in the axial direction in a non-contact manner in the X-axis direction and the Y-axis direction, FIG. 2 shows only a control portion in the X-axis direction.

As shown in FIG. 1, the radial magnetic bearing device includes a set of radial magnetic bearings (2) for supporting the rotating body (1) in a non-contact manner in the X-axis direction and the Y-axis direction. The magnetic bearing (2) is composed of a pair of X-axis electromagnets (2xa) (2xb) that sandwich the rotating body (1) from both sides in the X-axis direction and attracts outward, and a rotating body (1).
(1) is provided with a pair of Y-axis electromagnets (2ya) (2yb) for attracting outward from both sides in the Y-axis direction. Each X axis electromagnet
A pair of X-axis displacement sensors (2xa) and (2xb), which sandwich the rotating body (2) from both sides in the X-axis direction and detect the size of the gap in the X-axis direction with the rotating body (2). 3xa) and (3xb) are provided, and the size of the gap with the rotating body (2) is detected near the Y-axis electromagnets (2ya) and (2yb) by sandwiching the rotating body (2) from both sides in the Y-axis direction. 1 to do
A pair of Y-axis displacement sensors (3ya) (3yb) are provided.

As shown in FIG. 2, the control portion in the X-axis direction of the radial magnetic bearing device includes an X-axis displacement detection device (4x), an electromagnet control device (5x), and power amplifiers (6xa) (6xb). I have. The displacement detection device (4x) is composed of the above two X-axis displacement sensors
(3xa) and (3xb), and an operation unit (7x).
Calculates the displacement of the rotating body (1) in the X-axis direction from the outputs of the sensors (3xa) and (3xb), and outputs an X-axis displacement signal Vx '. The X-axis displacement signal Vx 'is directly input to the electromagnet controller (5x) as the controller input signal Vx. The electromagnet controller (5x)
It outputs position control signals Vcxa 'and Vcxb' for controlling the drive current of each X-axis electromagnet (2xa) (2xb) based on the input signal Vx which is the output signal of the displacement detection device (4x). Each position control signal Vcxa ', Vcxb' is directly used as an electromagnet control signal Vcxa, Vcxb as a corresponding power amplifier (6xa) (6x
Enter in b). Each power amplifier (6xa) (6xb) amplifies the electromagnet control signals Vcxa and Vcxb to amplify each X-axis electromagnet (2xa) (2xb)
Supplies the drive currents Icxa and Icxb, respectively. The drive current Icxa is applied to the two electromagnets (2xa) and (2xb), respectively.
, Icxb, the respective electromagnets (2xa) (2x
b) An outward magnetic attraction force in the X-axis direction is generated in the
A magnetic force Fcx in the X-axis direction acts on (1), whereby the rotating body (1) is non-contactly supported at a predetermined position in the X-axis direction.

The control section in the Y-axis direction of the radial magnetic bearing device has the same configuration as the control section in the X-axis direction in FIG.

FIGS. 3 and 4 show an example of an axial magnetic bearing device used in a high-speed rotating machine as described above. FIG. 3 is a longitudinal sectional view of a mechanical part of the axial magnetic bearing device, and FIG. 4 is a block diagram of a control part thereof.

As shown in FIG. 3, the axial magnetic bearing device includes a set of axial magnetic bearings (8) for supporting the rotating body (1) in a non-contact manner in the Z-axis direction. The magnetic bearing (8)
The rotating body (1) includes a pair of Z-axis electromagnets (8za) and (8zb) that sandwich the flange portion (1a) from both sides in the Z-axis direction and suction in opposite directions. In the vicinity of the end face of the rotating body (1), Z
One Z-axis displacement sensor that detects the size of the gap in the axial direction
(3z) is provided.

As shown in FIG. 4, the control portion of the axial magnetic bearing device includes a Z-axis displacement detection device (4z), an electromagnet control device (5z), and power amplifiers (6za) (6zb). The displacement detection device (4z) includes the one Z-axis displacement sensor (3z) described above,
A computing unit (7z), and the computing unit (7z) includes a sensor (3z).
, The displacement of the rotating body (1) in the Z-axis direction is obtained, and a Z-axis displacement signal Vz 'is output. The Z-axis displacement signal Vz 'is directly input to the electromagnet controller (5z) as the controller input signal Vz. The electromagnet controller (5z) controls each Z-axis electromagnet (8z) based on the displacement signal Vz, which is the output signal of the displacement detector (4z).
a) Output position control signals Vcza 'and Vczb' for controlling the drive current of (8zb). Each position control signal Vcz
a 'and Vczb' are used as they are for the electromagnet control signals Vcza and Vczb.
To the corresponding power amplifiers (6za) and (6zb). Each of the power amplifiers (6za) and (6zb) receives an electromagnet control signal Vcza, Vcz
b is amplified to supply drive currents Icza and Iczb to the respective Z-axis electromagnets (8za) and (8zb). And two electromagnets (8
When the drive currents Icza and Iczb are supplied to the za) and (8zb), respectively, a magnetic attraction force is generated in each of the electromagnets (8za) and (8zb) in a direction opposite to the Z-axis direction. A magnetic force Fcz acts in the direction, whereby the rotating body (1) is held at a predetermined position in the Z-axis direction.

In a high-speed rotating machine provided with the radial magnetic bearing device and the axial magnetic bearing device as described above, a disturbance acts on the rotating body (1) in addition to the magnetic force of each magnetic bearing device. In FIG. 2, the X-axis component of the disturbance is indicated by Fdx, and in FIG.
Indicated by dz. In the X-axis direction, a force Fx obtained by adding the magnetic force Fcx and the X-axis component Fdx of the disturbance acts on the rotating body (1). The same applies to the Y-axis direction. In the Z-axis direction, a force F obtained by adding the magnetic force Fcz and the Z-axis component Fdz of the disturbance
z acts on the rotating body (1).

There are various types of disturbance, but many have periodicity.

As the radial disturbance, for example, a rotating body
There is an imbalance of (1). In this case, whirling occurs in proportion to the unbalance amount on the rotating body at the time of rated rotation, and this often has a bad influence on rotation accuracy and control stability. As a method of reducing whirling of the rotating body due to unbalance, for example, a reference signal proportional to the rotation speed is generated by a rotation sensor, and based on this reference signal, without controlling a frequency component synchronized with the rotation speed, A so-called inertia center control for rotating a rotating body around its principal axis of inertia is known. However, in this case, a rotation sensor such as an encoder is separately required, and even if the rotating body is rotated around its main inertia axis, the whirling amount itself in proportion to the unbalance cannot be sufficiently reduced.
Further, a so-called peak-of-gain control for increasing the bearing rigidity only at a certain frequency (rotational speed) is known, but also in this case, disturbance cannot be suppressed when used in other rotational speed ranges.

On the other hand, when the speed of the rotating body increases, the natural frequency (rigid mode, primary bending mode, secondary bending mode) of the rotating body changes and branches as the rotating speed increases, that is, it has a gyro effect. . Then, at a rotational speed corresponding to each natural frequency, a gyro vibration is generated due to a disturbance or the like. For this reason, even if compensation is performed for the natural frequency in one state, gyro vibration is generated at a frequency corresponding to the natural frequency in another state. For a rotating body that rotates at a high speed, it is necessary to increase the difference between the actual rotation speed and the natural frequency as much as possible. However, it is difficult to increase the rotation speed due to the above-described circumstances.

As the axial disturbance, for example, a case is considered in which a magnetic bearing device is used for a spindle device of a machine tool such as a grinder. In a spindle device of a grinding machine, machining is often performed by applying a constant frequency oscillation (vibration) to the main shaft (rotating body) in the axial direction, but the oscillation frequency is set in a region where the bearing rigidity is low. In such a case, the main shaft vibrates largely in the axial direction due to insufficient rigidity of the bearing, which may adversely affect machining accuracy.
As a countermeasure, the above-described peak of gain control is known, but in this case, as described above, disturbance cannot be suppressed when used in another rotation speed region.

[0015]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to reduce the influence of the periodic disturbance even when the frequency of the disturbance changes. To provide a magnetic bearing device capable of high-speed rotation.

[0016]

A magnetic bearing device according to the present invention has a magnetic bearing having a plurality of electromagnets for supporting a rotating body in a non-contact manner, and supplies a drive current to the electromagnets based on an electromagnet control signal. A power amplifier, a displacement detection unit that detects a displacement of the rotating body, and an electromagnet control unit that outputs a position control signal for controlling a drive current of the electromagnet based on an output signal of the displacement detection unit.
A disturbance suppression control means for estimating a frequency of the periodic disturbance from the drive current of the electromagnet and outputting a disturbance suppression signal for suppressing the periodic disturbance, and adding the position control signal and the disturbance suppression signal to the electromagnet Adding means for supplying a control signal to the power amplifier.

The frequency of the periodic disturbance is estimated from the driving current of the electromagnet, and a disturbance suppression signal for suppressing the periodic disturbance is output. The signal is added to the position control signal and supplied to the power amplifier as the electromagnet control signal. Therefore, even if the frequency of the disturbance changes, the effect can always be reduced. For this reason, in any rotation speed range, vibration of the rotating body due to disturbance is suppressed, control with high stability can be performed, and high-speed rotation can be performed.

The magnetic bearing according to the present invention also includes a magnetic bearing having a plurality of electromagnets for supporting the rotating body in a non-contact manner, a power amplifier for supplying a driving current to the electromagnet based on an electromagnet control signal, Displacement detection means for detecting the displacement, electromagnet control means for outputting an electromagnet control signal for controlling the drive current of the electromagnet based on the output signal of the displacement detection means, and the frequency of the periodic disturbance from the electromagnet control signal And a disturbance suppression control means for outputting a disturbance suppression signal for suppressing the periodic disturbance, and an addition means for supplying a signal obtained by adding the output of the displacement detection means and the disturbance suppression signal to the electromagnet control means. Are provided.

In order to estimate the frequency of the periodic disturbance from the electromagnet control signal and to output a disturbance suppression signal for suppressing the periodic disturbance, to add this to the output of the displacement detection means and to supply it to the electromagnet control means , Even if the frequency of the disturbance changes,
The effect can always be reduced. For this reason, in any rotation speed range, vibration of the rotating body due to disturbance is suppressed, control with high stability can be performed, and high-speed rotation can be performed.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS.
An embodiment of the present invention will be described.

FIG. 5 shows a first embodiment in which the present invention is applied to a radial magnetic bearing device. FIG. 5 corresponds to FIG. 2 showing the prior art, and the same parts as those in FIG. 2 are denoted by the same reference numerals. The configuration of the mechanical part of the radial magnetic bearing device according to the first embodiment is the same as that of the prior art shown in FIG.

In the first embodiment, an X-axis displacement detecting device
(4x) is an X-axis displacement detecting means for detecting the displacement of the rotating body (1) in the X-axis direction, and the electromagnet controller (5x) is based on a displacement signal Vx 'which is an output signal of the displacement detecting device (4x). Each X-axis electromagnet (2
x-axis electromagnet control means for outputting position control signals Vcxa ', Vcxb' for controlling the drive currents Icxa, Icxb of (xa) and (2xb), respectively.

In the case of the first embodiment, a disturbance suppression control device (9x) as disturbance suppression control means is provided in parallel with the power amplifiers (6xa) and (6xb) in the control portion in the X-axis direction of the radial magnetic bearing device. ing. As will be described in detail later, the disturbance suppression control device (9x) estimates the frequency of the periodic disturbance from the drive currents Icxa and Icxb, and outputs disturbance suppression control signals Vrxa and Vrxb for suppressing the periodic disturbance. . The disturbance suppression control device (9x) includes a DSP (digital signal processor). A digital signal processor (Digital Signal Processor) refers to dedicated hardware that inputs a digital signal, outputs a digital signal, is capable of software programming, and is capable of high-speed real-time processing. Then, a disturbance suppression control device (9
The processing in x) is performed by executing a DSP program. The one position control signal Vcxa ′ from the electromagnet control device (5x) and the one disturbance suppression control signal Vrxa from the disturbance suppression control device (9x) are added by one adder (10xa) that constitutes adding means. , Electromagnet control signal Vcxa
And supplied to one power amplifier (6xa). The other position control signal Vcxb ′ from the electromagnet control device (5x) and the other disturbance suppression control signal Vrxb from the disturbance suppression control device (9x) are added by the other adder (10xb) that constitutes adding means. , The other power amplifier (6
xb). Others are the same as those of the prior art shown in FIGS.

Next, an example of the operation of the disturbance suppression control device (9x) will be described with reference to the flowcharts of FIGS.

In FIG. 6, first, the drive currents Icxa, Icxa
The sampling of cxb is performed for a predetermined time (step 101).
Then, the frequency ω of the periodic disturbance is estimated based on the sampling result (step 102).

Next, an example of an algorithm for estimating ω will be described.

This algorithm considers a signal d (t) having a period of τ ^* , and evaluates an evaluation function J expressed by the following equation (1).
This is a method based on the gradient minimization method of (τ).

[0028]

(Equation 1) Here, T _max > τ ^* . From equation (1), intuitively,
If τ coincides with the period of d (t), the evaluation function J becomes 0 at the minimum. A continuous gradient adaptation algorithm that minimizes the evaluation function J is given by the following equation (2).

[0029]

(Equation 2) Assuming that the sampling time is ΔT, _Tmax and τ are represented by ΔT as shown in the following equation (3).

_Tmax = LΔT, τ = ηΔT (3) where L is an integer and η is a real number. If the integer part of the real number η is defined as | η |, then both η and the adjacent integers are | η | and (| η | +1).

For discrete data (d ₁ ,..., D _L ,..., D _{2L + 2} ) whose sampling time is ΔT, η = τ / ΔT is not an integer. In, the evaluation function can be approximated as in the following equations (4) and (5).

[0032]

(Equation 3) The partial differentiation of the evaluation function J at both integer points is
It is expressed as the following equations (6) and (7).

[0033]

(Equation 4) Then, the partial differential of the evaluation function J at the point τ = ηΔT is
The following equation (8) is obtained by linear interpolation of partial differentiation of the evaluation function J at the points | η | ΔT and (| η | +1) ΔT.

[0034]

(Equation 5) Using this equation (8), the above equation (2) can be rewritten as the following equation (9).

[0035]

(Equation 6) Next, the algorithm of the above-mentioned ω estimation will be described with reference to the flowchart of FIG.

In FIG. 7, first, regarding the evaluation function J represented by the above-mentioned equation (1), the above-mentioned equations (6) and (7)
Is used to calculate partial derivatives at the point | η | ΔT and the point (| η | +1) ΔT (step 201). Next, the partial derivative of J at the point ηδT is calculated by linear interpolation using the calculated values of these partial derivatives and the above equation (8) (step
202). Next, the updated value η (t + 1) of η (t) is calculated using the above equation (9) (step 203). Next, J
Is compared with the small value ε (step 204). If J is equal to or larger than ε, the process returns to step 201 and steps 201 to 204 are repeated. In step 204, if J is smaller than ε,
Proceeding to step 205, the period τ is calculated using the following equation (10). Then, this τ is converted into a frequency ω (step
206), end the processing.

In FIG. 6, after the estimation of the frequency ω in step 102 is completed, the processing in step 103 and subsequent steps is performed to generate a disturbance suppression signal. Before describing this process, the principle of generating a disturbance suppression signal will be described with reference to FIGS.

FIG. 8 schematically shows the entire configuration of the control system. In FIG. 8, reference numeral (11) denotes an object to be controlled, and corresponds to the radial magnetic bearing (2) of the first embodiment. (12) is a disturbance suppression control device corresponding to the disturbance suppression control device (9x) of the first embodiment. d is a disturbance corresponding to the disturbance Fdx of the first embodiment. e is an error signal output from the control target (11), and corresponds to the drive currents Icxa and Icxb of the first embodiment. r is an output signal of the disturbance suppression control device (12), that is, a control input to the control target (11), and corresponds to the disturbance suppression control signals Vrxa and Vrxb of the first embodiment.

FIG. 9 shows DS in the disturbance suppression control device (12).
FIG. 3 is a block diagram showing processing performed by executing the program P. The processing in the control device (12) includes synchronous energy calculating means (13), Fourier coefficient calculating means (14), and signal generating means. (15).

FIG. 10 is a block diagram showing the processing in the synchronization energy calculating means (13).
The processing in (3) includes two multipliers (16) and (17) and two low-pass filters (18) and (19).

It is assumed that the disturbance d is given as in the following equation (10), and the transfer function G (s) of the control target (11) is as in the following equation (11).

D = α _d sin (ωt) + β _d cos (ωt) (10) G (jw) = Ae ^jθ (11) Then, the control input r to the control target (11) is given by the following equation. Given as (12).

R = α (t) sin (ωt) + β (t) cos (ωt) (12) For the control input r, the steady output y and the error signal e of the control target (11) are expressed by the following equation. (13) and equation (14).

Y = A [α (t) sin (ωt + θ) + β (t) cos (ωt + θ)] (13) e = A [α (t) sin (ωt + θ) + β (t) cos (ωt + θ)] + Α _d sin (ωt) + β _d cos (ωt) (14) The synchronization energy calculation means (13) processes the error signal e,
Generate n ₁ (t) and n ₂ (t). One multiplier
In (16), the product of e (t) and sin (ωt) is calculated, and this product e (t) sin (ωt) is used as one filter.
(18) to generate n ₁ (t) as its output. Similarly, in the other multiplier (17), e (t) and c
os (ωt) is calculated, and the product e (t) cos
(Ωt) is passed through the other filter (19) to produce n ₂ (t) as its output. The cutoff frequencies ω _B of the filters (18) and (19) are selected so as to satisfy the relationship ω _B << 2ω. Here, ignoring the high-frequency component having a very small gain, the outputs of the filters (18) and (19) in the steady state are approximately expressed by the following equations (15) and (16).

N ₁ (t) = 0.5 [Aαcos (θ) + α _d −Aβsin (θ)] (15) n ₂ (t) = 0.5 [Aβcos (θ) + β _d −Aαsin (θ) )] (16) In general, since the phase angle θ is unknown, the Fourier coefficients α (k) and β (k) of the control input r are expressed by the following equations (17) and (18).
become that way.

Α (k + 1) = α (k) −μ ₁ (k + 1) n ₁ (k) (17) β (k + 1) = β (k) −μ ₂ (k + 1) n ₂ (k) (18) Here, μ _i is a step size. Also, n ₁ (k
+1) and n ₂ (k + 1) are calculated by the following equations (19) and (2).
0).

N ₁ (k + 1) = n ₁ (k) +0.5 A [μ ₂ (k + 1) n ₂ (k) sin (θ) −μ ₁ (k + 1) n ₁ (k) cos (θ)] (19) n ₂ (k + 1) = n ₂ (k) −0.5 A [μ ₂ (k + 1) n ₂ (k) cos (θ) + μ ₁ (k + 1) n ₁ (k) sin (θ)] (20) Here, μ ₁ (k + 1) and μ ₂ (k + 1) are as shown in the following equations (21) and (22).

[0048] _{μ 1 (k + 1) =} μ 1 (k) sgn ^{_{[n 1 2 (k-1)}} -n 1 2 (k) ] _{...... (21) μ 2 (k} + 1) = μ 2 (k) sgn [ ^{_{n 2 2 (k-1)}} -n 2 2 (k) ] ...... (22) the above equation is a nonlinear system, the nonlinear system under certain conditions has been found to be asymptotically stable. Also, the above equation
From (15), equations (16) and (14), n ₁ (t) and n
_{When 2} (t) converges to 0, the error signal e (t) converges to 0.

In FIG. 6, in step 103, sin
The calculation of (ωt) is performed. Next, V _x and sin (ω
t) is calculated (step 104), and the product V _x si
n (ωt) is passed through a low-pass filter (18)
₁ (t) and n ₁ (k) are obtained (step 105).
Then, n ₁ ² is computed, which is a Y ₁ (step 106). Then, Y ₁ (k) and Y _{1 (k-1)} and are compared (step 107), Y ₁ (k) is Y _{1 (k-1)}
If so, go to step 108; otherwise go to step 109. In step 108, the following equation (2
Μ ₁ (k + 1) is obtained by 3), and the routine proceeds to step 110.

Μ ₁ (k + 1) = − μ ₁ (k) (23) In step 109, μ ₁ (k + 1) is obtained by the following equation (24), and the routine proceeds to step 110.

Μ ₁ (k + 1) = μ ₁ (k) (24) While steps 103 to 109 are being executed, the same steps 111 to 117 are executed at the same time.

In step 111, calculation of cos (ωt) is performed. Next, a product of V _x and cos (ωt) is calculated (step 112), and the product V _x cos (ωt) is passed through a low-pass filter (19) to obtain n ₂ (t), n ₂ ( k)
Is obtained (step 113). Then, n ₂ ² is computed, which is a Y ₂ (step 114). Next, Y
₂ (k) and Y ₂ (k-1) are compared (step 115).
), If Y ₂ (k) is greater than Y ₂ (k−1), the process proceeds to step 116; otherwise, the process proceeds to step 117. In step 116, μ ₂ (k +
1) is obtained, and the routine proceeds to step 110.

Μ ₂ (k + 1) = − μ ₂ (k) (25) In step 117, μ ₂ (k + 1) is obtained by the following equation (26), and the flow proceeds to step 110.

Μ ₂ (k + 1) = μ ₂ (k) (26) In step 110, α _{2 is} obtained from the above equations (17) and (18).
(K + 1) and β (k + 1) are obtained, and using these, the control input r is calculated by the following equation (27) (step 111).

R = α (k + 1) sin (ωt) + β (k + 1) cos (ωt) (27) Then, the disturbance suppression control signals Vrxa and Vrxb are generated from the r, and the adders (10xa) and (10xb) Supplied to

In the first embodiment, the disturbance suppression control device (9x)
, The frequency of the periodic disturbance is estimated from the drive currents Icxa and Icxb, and disturbance suppressing signals Vrxa and Vrxb for suppressing the periodic disturbance are output. The adder (10xa) (10xb) outputs the disturbance suppressing signal Vrxa , Vrxb to the position control signal Vc
xa ', Vcxb' and add them to the electromagnet control signals Vcxa,
The power is supplied to the power amplifiers (6xa) and (6xb) as cxb, thereby controlling the drive currents Icxa and Icxb of the electromagnets (2xa) and (2xb). can do. Therefore, in any rotational speed range, the vibration of the rotating body (1) due to the disturbance is suppressed, the control with high stability can be performed, and the high-speed rotation can be performed.

FIG. 11 shows a second embodiment in which the present invention is applied to a radial magnetic bearing device. FIG. 11 shows the first
This corresponds to FIG. 5 of the embodiment, and the same parts as those in FIG. 5 are denoted by the same reference numerals. Also, the configuration of the mechanical part of the radial magnetic bearing device according to the second embodiment is the same as that of the prior art shown in FIG.

In the case of the second embodiment, in the control portion in the X-axis direction of the radial magnetic bearing device, the disturbance suppression control device (9
x) is provided in parallel with the electromagnet control device (5x). Position control signals Vcxa ′, Vcx output from the electromagnet controller (5x)
b 'is input as it is to the power amplifiers (6xa) and (6xb) as electromagnet control signals Vcxa and Vcxb. Disturbance suppression controller (9x)
Has a configuration similar to that of the disturbance suppression control device (9x) in the first embodiment, and the electromagnet control signals Vcxa, Vcx
The frequency ω of the periodic disturbance is estimated from cxb, and a disturbance suppression control signal Vrx for suppressing the periodic disturbance is output.
The position detection signal Vx ′, which is the output of the X-axis displacement detection device (4x), and the disturbance suppression control signal Vrx from the disturbance suppression control device (9x) are added by an adder (10x) that constitutes adding means.
The control device input signal Vx is supplied to the electromagnet control device (5x). Others are the same as in the first embodiment.

Also in the second embodiment, the disturbance suppression control device (9x)
, The frequency of the periodic disturbance is estimated from the electromagnet control signals Vcxa and Vcxb, and a disturbance suppression signal Vrx for suppressing the periodic disturbance is output. The adder (10x) converts the disturbance suppression signal Vrx into a displacement detection signal. Vx ', and supplies it to the electromagnet controller (5x) as a control device input signal Vx, whereby the drive currents Icxa, Icxa, Icxa, Ixx
Since cxb is controlled, even if the frequency of the disturbance changes,
The effect can always be reduced. Therefore, in any rotational speed range, the vibration of the rotating body (1) due to the disturbance is suppressed, the control with high stability can be performed, and the high-speed rotation can be performed.

FIG. 12 shows a third embodiment in which the present invention is applied to an axial magnetic bearing device. FIG. 12 corresponds to FIG. 4 showing the prior art, and the same parts as those in FIG. 4 are denoted by the same reference numerals. The configuration of the mechanical part of the axial magnetic bearing device according to the third embodiment is the same as that of the prior art shown in FIG.

In the third embodiment, a Z-axis displacement detecting device
(4z) is a Z-axis displacement detecting means for detecting the displacement of the rotating body (1) in the Z-axis direction, and the electromagnet controller (5z) is based on a displacement signal Vz 'which is an output signal of the displacement detecting device (4z). Each Z-axis electromagnet (8
za) and (8zb) constitute Z-axis electromagnet control means for outputting position control signals Vcza 'and Vczb' for controlling the drive currents Icza and Iczb, respectively.

In the case of the third embodiment, a disturbance suppression control device (9z) as disturbance suppression control means is provided in parallel with the power amplifiers (6za) and (6zb) in the control portion of the axial magnetic bearing device. The disturbance suppression control device (9z) has the same configuration as that of the disturbance suppression control device (9x) in the first embodiment, and estimates the frequency ω of the periodic disturbance from the drive currents Icza and Iczb, as described above. It outputs disturbance suppression control signals Vrza and Vrzb for suppressing periodic disturbance. One position control signal Vcza 'from the electromagnet control device (5z) and one disturbance suppression control signal Vrza from the disturbance suppression control device (9z) are added by one adder (10za) which constitutes addition means. ,
It is supplied to one power amplifier (6za) as an electromagnet control signal Vcza. The other position control signal Vczb 'from the electromagnet control device (5z) and the other disturbance suppression control signal Vrzb from the disturbance suppression control device (9z) are added by the other adder (10zb) constituting the adding means. Is supplied to the other power amplifier (6xb) as an electromagnet control signal Vczb. Others are the same as those of the prior art of FIGS. 3 and 4 and the first embodiment.

Also in the third embodiment, the disturbance suppression control device (9z)
, The frequency of the periodic disturbance is estimated from the driving currents Icza and Iczb, and disturbance suppressing signals Vrza and Vrzb for suppressing the periodic disturbance are output. The adder (10za) (10zb) outputs the disturbance suppressing signal Vrza , Vrzb to the position control signal Vc
za ', Vczb' and add them to the electromagnet control signals Vcza, Vcb.
The power is supplied to the power amplifiers (6za) and (6zb) as czb, which controls the drive currents Icza and Iczb of the electromagnets (8za) and (8zb). can do. Therefore, in any rotational speed range, the vibration of the rotating body (1) due to the disturbance is suppressed, the control with high stability can be performed, and the high-speed rotation can be performed.

FIG. 13 shows a fourth embodiment in which the present invention is applied to an axial magnetic bearing device. FIG. 13 corresponds to FIG. 12 of the third embodiment, and the same parts as those in FIG. 12 are denoted by the same reference numerals. Also, the fourth
The configuration of the mechanical part of the axial magnetic bearing device according to the embodiment is the same as that of the prior art shown in FIG.

In the case of the fourth embodiment, in the control portion of the axial magnetic bearing device, a disturbance suppression control device (9z) is provided in parallel with the electromagnet control device (5z). The disturbance suppression control device (9z) is the disturbance suppression control device (9
x), and the electromagnet control signal V
The frequency ω of the periodic disturbance is estimated from cza and Vczb, and a disturbance suppression control signal Vrz for suppressing the periodic disturbance is output. The position detection signal Vz ′ output from the Z-axis displacement detection device (4z) and the disturbance suppression control signal Vrz from the disturbance suppression control device (9z) are added by an adder (10z) that constitutes adding means, and control is performed. It is supplied to one of the electromagnet controllers (5z) as a device input signal Vz. Others are the same as in the third embodiment.

Also in the fourth embodiment, the disturbance suppression control device (9z)
, The frequency of the periodic disturbance is estimated from the electromagnet control signals Vcza and Vczb, and a disturbance suppression signal Vrz for suppressing the periodic disturbance is output. The adder (10z) converts the disturbance suppression signal Vrz into a displacement detection signal. Vz ', which is supplied to the electromagnet controller (5z) as a control device input signal Vz, whereby the drive currents Icza, Icza, Icza, Izza, Izza,
Because czb is controlled, even if the frequency of the disturbance changes,
The effect can always be reduced. Therefore, in any rotational speed range, the vibration of the rotating body (1) due to the disturbance is suppressed, the control with high stability can be performed, and the high-speed rotation can be performed.

The rotating body has two sets of radial magnetic bearing devices and one set.
When applying the present invention to a high-speed rotating machine that is non-contact supported by a set of axial magnetic bearing devices and is rotated at a high speed,
If only whirling in the radial direction due to unbalance of the rotating body becomes a problem, two sets of radial magnetic bearing devices may be configured as in the first embodiment or the second embodiment. In this manner, radial vibration of the rotating body due to disturbance can be suppressed in any rotational speed range. Further, there is no need for a rotation sensor such as an encoder as in the case of the conventional inertial center control. Further, even if gyro vibration appears at some natural frequencies due to disturbance, this is suppressed in a short time, and stable rotation and high speed rotation can be performed. Also, when the present invention is applied to a spindle device of a grinding machine that performs machining by applying a constant frequency oscillation to a rotating body (spindle) in the axial direction, an axial magnetic bearing device is used as in the third embodiment or the fourth embodiment. What is necessary is just to comprise. In this manner, regardless of the oscillation frequency, axial vibration of the rotating body due to the oscillation can be suppressed, and high-precision machining can be performed. In this case, the radial magnetic bearing device may be a conventional one, but it is preferable that the radial magnetic bearing device is also configured as in the first embodiment or the like so as to suppress vibration due to radial disturbance.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one example of a mechanical configuration of a radial magnetic bearing device.

FIG. 2 is a block diagram showing a configuration of a control part in an X-axis direction of a conventional radial magnetic bearing device.

FIG. 3 is a longitudinal sectional view showing an example of a mechanical configuration of the axial magnetic bearing device.

FIG. 4 is a block diagram showing a configuration of a control portion of a conventional axial magnetic bearing device.

FIG. 5 is a block diagram of a control portion in the X-axis direction of the radial magnetic bearing device according to the first embodiment of the present invention.

FIG. 6 is a flowchart illustrating an example of a process of the disturbance suppression control device.

FIG. 7 is a flowchart illustrating an example of a process of a part of estimating a frequency of a periodic disturbance in FIG. 6;

FIG. 8 is a block diagram of a control system for explaining processing of a disturbance suppression control device.

FIG. 9 is a block diagram illustrating processing in the disturbance suppression control device.

FIG. 10 is a block diagram illustrating a process in a synchronization energy calculating unit in FIG. 9;

FIG. 11 is a block diagram of a control portion of a radial magnetic bearing device according to a second embodiment of the present invention.

FIG. 12 is a block diagram of a control portion of an axial magnetic bearing device according to a third embodiment of the present invention.

FIG. 13 is a block diagram of a control portion of an axial magnetic bearing device according to a fourth embodiment of the present invention.

[Explanation of symbols]

(1) Rotating body (2) Radial magnetic bearing (2xa) (2xb) X-axis electromagnet (2ya) (2yb) Y-axis electromagnet (4x) X-axis displacement detection device (X-axis displacement detection means) (4z) Z-axis displacement Detector (Z-axis displacement detector) (5x) X-axis electromagnet controller (X-axis electromagnet controller) (5z) Z-axis electromagnet controller (Z-axis electromagnet controller) (6xa) (6xb) X-axis power amplifier ( (6za) (6zb) Z-axis power amplifier (8) Axial magnetic bearing (8za) (8zb) Z-axis electromagnet (9x) X-axis disturbance suppression control device (X-axis disturbance suppression control means) (9z) Z-axis disturbance suppression control device (Z axis disturbance suppression control means) (10xa) (10xb) Adder (addition means)

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Manabu Taniguchi 3-5-8 Minamisenba, Chuo-ku, Osaka Koyo Seiko Co., Ltd.

Claims (2)

[Claims] A magnetic bearing having a plurality of electromagnets for supporting the rotating body in a non-contact manner; a power amplifier for supplying a driving current to the electromagnet based on an electromagnet control signal; and a displacement detecting means for detecting a displacement of the rotating body. And electromagnet control means for outputting a position control signal for controlling the drive current of the electromagnet based on the output signal of the displacement detection means; and estimating the frequency of the periodic disturbance from the drive current of the electromagnet, and Disturbance suppression control means for outputting a disturbance suppression signal for suppressing sexual disturbance, and addition means for adding the position control signal and the disturbance suppression signal to supply an electromagnet control signal to the power amplifier. A magnetic bearing device characterized by the above-mentioned. 2. A magnetic bearing having a plurality of electromagnets for supporting a rotating body in a non-contact manner, a power amplifier for supplying a driving current to the electromagnet based on an electromagnet control signal, and a displacement detecting means for detecting a displacement of the rotating body. And an electromagnet control means for outputting an electromagnet control signal for controlling a driving current of the electromagnet based on an output signal of the displacement detection means; and estimating a frequency of a periodic disturbance from the electromagnet control signal to determine the periodicity. A disturbance suppression control unit that outputs a disturbance suppression signal for suppressing disturbance, and an addition unit that supplies a signal obtained by adding the output of the displacement detection unit and the disturbance suppression signal to the electromagnet control unit. Characteristic magnetic bearing device.