JPH09120301A - Filter circuit for controlling rotary body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the control circuit for the rotary body which easily separates two opposite-sign modes with absolute values extremely close to each other. SOLUTION: Input signal related to an (x) and (y) axis is represented by one complex variable (U), and the transfer function of a low-pass or high-pass filter with a real number coefficient is represented by F(s), and S of F(s) is replaced by (s-jω), where ω is an either positive or negative center angular frequency to be passed or stopped and (j) is the imaginary number unit, to obtain a complex transfer function F(s-jω); and the output signal, related to the (x) and (y) axes which are obtained by passing an input U through the complex transfer function F(s-jω) is represented by one complex variable (V) to obtain a transfer representation equation U.F(s-jω)=V. Both sides of the above transfer representation equation are multiplied by the denominator of F(s-jω) and a connection is made by a transfer element with a real coefficient so as to make the real part and the imaginary part of the above transfer representation equation become equal to each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotor control filter circuit, a control circuit or a control system used for controlling a magnetic bearing used in, for example, a high speed rotating machine.

[0002]

2. Description of the Related Art Generally, a rotating shaft of a rotating body supported by a magnetic bearing is associated with whirling phenomena of a center of gravity (translational movement) of the rotating body and a tilting movement (posture movement) around the center of gravity. In order to suppress such whirling phenomenon, state quantities such as position, speed, and tilt angle are detected, and the current applied to the electromagnet is controlled based on the detected state quantities. As means for such control, for example, by passing the state quantities related to the radial two axes, x and y axes, which are orthogonal to the rotation axis detected by the sensor, through a control circuit having a transfer function suitable for the purpose of control. , A method of obtaining a predetermined output signal, or a method of using a state quantity estimator called an observer. At that time, the control circuit has conventionally been designed and constructed based on the transfer function of the real number coefficient.

[0003]

In the conventional vibration suppression method as described above, it is difficult to separate vibration modes of opposite signs whose absolute values are equal to or extremely close to each other. In the flexible mode of the rotating body, there are often two modes of opposite signs whose absolute values are extremely close to each other. One of them is given enough attenuation for some reason, so I don't want to touch that mode, but if the other remaining mode is unstable, then just the unstable mode You have to choose. However, in the conventional method as described above, it is not possible to select only that mode, so both modes are controlled simultaneously,
There were times when the touch-free mode was adversely affected.

Further, in the control of a high-speed rotating body, a filter circuit for passing or blocking only a narrow bandwidth near the rotating speed of the rotating body has a zero-rotating speed by coordinate conversion from stationary coordinates to rotating body coordinates. It has been a conventional method to obtain a steep characteristic by replacing with. To that end,
As disclosed in Japanese Patent No. 25, it is necessary to configure two sets of coordinate conversion circuits that generate and generate a cosine function corresponding to the rotation angle of the rotating body in addition to the low-pass filter.

Further, in the above-mentioned conventional method, it has been impossible to adjust the phase to an arbitrary value regardless of the frequency like the gain.

The present invention provides a control circuit for a rotating body which facilitates the separation of two modes of opposite sign of equal absolute value or very close in absolute value, and also adjusting the gain and phase independently of frequency. It is an object of the present invention to provide a control circuit capable of performing.

By the way, the conventional low-pass or high-pass filter does not distinguish positive or negative in the angular frequency Ω of the signal, and has a gain characteristic symmetrical with respect to the origin, that is, zero frequency, even if the negative region of the frequency is included. This means that the filter is used as a bandpass or band rejection filter having zero as a center frequency. Therefore, as shown in FIG. 16, the higher the corner frequency (a, b), the wider the bandwidth, and the abscissa represents the logarithmic scale of the angular frequency lo.
It was difficult to obtain a steep gain characteristic when a linear scale was used instead of gΩ.

In the normal Bode plot gain characteristic, the slope (dB / dec) of the polygonal line approximation is apparently the same in all frequency regions, but the higher the frequency of the polygonal point, the more abscissa the non-logarithmic frequency changes. It can be easily understood from the fact that (increment) becomes much larger. For example, when the breakpoint frequencies are 10 and 1000, the change per 1dec is
Since 100−10 = 90 and the latter is 10000−1000 = 9000, even with the same inclination, the former is 100 times steeper on a linear scale.

In controlling the rotating body, since control is performed from two radial orthogonal axes, a complex variable using an imaginary number multiplied by j is often used as a signal related to the x-axis and a signal related to the y-axis. . A complex coefficient transfer function including complex coefficients is an extremely effective means in that case. In such a complex system, the positive and negative of the frequency should be distinguished, and the characteristic root of the system is not necessarily the conjugate root.

For example, a first-order low-pass filter a / (a +
In s), it may be considered that a is the corner angular frequency and zero is the central angular frequency at the same time. Therefore, in a complex system, the central angular frequency is not limited to zero.
{A + (s-jω)} changes to a complex coefficient transfer function with ω as the symmetry point. At the same time, a is not from zero, but a distance from ω or half the passband. Even if ω is a high value, it will be returned to the origin, so in the above example, ω is 1000,
If a is selected as 10, the slope of the polygonal line is about 100 on a logarithmic scale.
Double steepness is obtained, and of course, (ω-a) on the opposite side of ω also becomes a break point, and thin steep bandpass characteristics are obtained.
(Figure 17). Further, it has been conventionally impossible to sharply change the phase by ± 180 ° between certain specific angular frequencies.
The present invention has been made based on the above findings.

[0011]

According to a first aspect of the present invention, a radial two-axis orthogonal to the rotation axis (z axis) of a rotating body is provided.
In a system that controls (x, y axes) by electromagnetic force, etc., the x, y
Axis related input signal (the Laplace conversion amount is Ux,
Uy) is expressed by one complex variable ( U = Ux + jUy),
F (s) is the transfer function of the low-pass or high-pass filter with real coefficients, ω is the central angular frequency of positive or negative to be passed or blocked, j is the imaginary unit, and Laplace operator s of the transfer function F (s) is (s The complex coefficient transfer function replaced by −jω) is F (s−jω), and the input U is the complex coefficient transfer function F
The output signals related to the x and y axes that have passed (s-jω) (the Laplace transform amounts thereof are Vx and Vy, respectively) are converted into one complex variable.
In the transfer expression U · F (s−jω) = V (1) obtained by expressing ( V = Vx + jVy), the transfer after multiplying both sides of the expression by the denominator of F (s−jω) This is a filter circuit for controlling a rotating body, characterized in that the real number part and the imaginary number part of the expression are connected by transfer elements having real number coefficients so that they are equal to each other.

According to a second aspect of the present invention, the positive or negative center angular frequencies to be passed or blocked are ω ₁ and ω ₂ , respectively, and ω ₁ ≠ ω ₂ , and the bandwidth around ω ₁ is around. In order to pass the component including (2a) and block the component including the bandwidth (2b) before and after ω ₂ as a center, k is an arbitrary gain or coefficient, and z is a dimensionless constant, The complex coefficient transfer function is k (s + b−jω ₂ ) / (s + a
-Jω ₁ ) or k (s + b-jω ₂ ) / {(s-jω ₁ ) ² +2
It is given in the form of za (s-jω ₁ ) + a ² }, and is the filter circuit for controlling a rotating body according to claim 1.

According to a third aspect of the present invention, k is an arbitrary gain or coefficient in the numerator and / or denominator of the transfer function F (s) according to the first aspect, and 2a is the center angular frequency. Let k (s ² + 2za) be the pass or stop bandwidth
s + a ² ), including quadratic system, replacing s with (s−jω) and arbitrarily selecting the dimensionless number z, near the bending points at both ends of the bandwidth in the gain characteristic of the frequency characteristic of the filter. Is closer to the ideal filter. The rotating body control filter circuit according to claim 1, wherein

According to a fourth aspect of the present invention, a plurality of filter circuits for controlling a rotating body according to any one of the first to third aspects are combined to specify a specific frequency band including a negative frequency region. It is a filter circuit for controlling a rotating body, characterized in that it passes or blocks the band. Of course, not only the passing or blocking of the gain characteristic, but also the phase characteristic can be used.

According to a fifth aspect of the present invention, in the rotating body control filter circuit according to any one of the first to fourth aspects, instantaneous values are input as variables without using ω, ω ₁ and ω ₂ as constants. The tracking filter is characterized in that

According to a sixth aspect of the present invention, there is provided a rotating shaft of a rotating body.
In a system for controlling radial two axes (x, y axes) orthogonal to the (z axis) by electromagnetic force or the like, a filter portion for extracting a necessary angular frequency component or band component from an input signal regardless of positive or negative, It consists of the part that gives the required phase angle to the extracted component, and the output that has passed through both parts is used to estimate other state quantities required for control, or the feedback is used to stabilize the mode of the extracted component. In the control circuit of the rotating body for converting, the part that gives the phase angle is
A, is the complex gain circuit represented by A + jB≡ Fc to the a real constant B, Fc of the x, the input to the y-axis portion (Ux, Uy) and output (Vx, Vy) between the Vx = AUx-BUy, Vy = BUx + AUy
By connecting A and B arbitrarily, the phase of the output can be increased or decreased by an arbitrary phase angle irrespective of the input frequency, and a frequency required for estimating a control or a control-related signal is obtained. It is a control circuit for a rotating body, which is characterized by giving an arbitrary required phase angle only to a region.

According to a seventh aspect of the present invention, in a system for controlling radial two axes orthogonal to the rotation axis of the rotating body by electromagnetic force or the like, a related signal in the radial two axis directions is input and a control signal in the two axis directions is input. Is a filter circuit for controlling a rotating body for extracting a positive or negative angular frequency component required for the above-mentioned configuration, wherein an integrator is provided in the signal path of each axis, and a pass band width of 1
Negative feedback with a gain of / 2 is performed, and feedback that intersects between the axes from each integrator is
The feedback from the first axis to the second axis is positive and the feedback from the second axis to the first axis is negative, and the central angular frequency to be passed is inserted as a gain in both feedback paths. It is a filter circuit for controlling a rotating body, wherein an angular frequency component is selectively passed.

According to the invention described in claim 8, in a system for controlling a radial two-axis orthogonal to the rotation axis of a rotating body by an electromagnetic force or the like, a related signal in the radial two-axis direction is input and a control signal in the two-axis direction is input. Is a filter circuit for controlling a rotating body for blocking or passing a positive or negative angular frequency component required for the above-mentioned configuration, which is a direct connection path having a gain of 1 in a signal path of each axis and a primary path parallel to and branched from the path. Of the low pass filter, and a value obtained by subtracting 1/2 of the stop band width of the low pass filter or the stop band width (the difference between the outer corner frequencies of the outer corners) in the case of gain is gained to the output. , And return to the direct connection path for subtractive coupling, provide a path for crossing between the axes from the output of each low pass filter and feeding back to the low pass filter, and the path is blocked or passed. The central angular frequency is inserted as a gain, and at the connection point, the paths from the first axis to the second axis are combined so as to be added, and the paths from the second axis to the first axis are combined so as to be subtracted. This is a filter circuit for controlling a rotating body, characterized in that a signal of a central band component is blocked or passed.

According to a ninth aspect of the present invention, in a system in which a radial two-axis orthogonal to the rotation axis of a rotating body is controlled by an electromagnetic force or the like, a related signal in the radial two-axis direction is input and a control signal in the two-axis direction is input. Positive or negative angular frequency component ω required to construct
A rotary body control filter circuit for passing ₁ and blocking other positive or negative angular frequency component ω _2, which is a direct connection path having a gain of 1 and branched from each of the signal paths of each axis. Two parallel circuits are provided, and one of the two parallel circuits has a pass band width of 1 which is a break point angular frequency of a first-order low-pass filter connected from the angular frequency of 1/2 of the stop band width to the rear part thereof. The value obtained by subtracting / 2 is given as a gain to be an input to the low-pass filter, and ω ₁ −ω ₂ is given to the other parallel circuit as a gain. , First at the connection point
The path from the axis to the second axis is combined so that the path from the second axis to the first is subtracted, and one of the outputs of the low-pass filter is additively connected to the direct connection path, and the other output is Cross-feedback between the axes is given to the input section of the low-pass filter to give ω ₁ as a gain, and at the connection point at the input section, the paths from the first axis to the second axis are added, and from the second axis to the first axis. The rotation system is characterized in that the paths to the axes are coupled so as to be subtractive so that the bandwidth near ω ₁ is passed and the bandwidth near ω ₂ is blocked. It is a service filter circuit.

According to a tenth aspect of the present invention, in a system for controlling radial two axes orthogonal to the rotation axis of a rotating body by electromagnetic force or the like, a related signal in the radial two axis directions is input and a control signal in the two axis directions is input. Is a control circuit for outputting a desired angular frequency component or band from the input signal regardless of whether it is positive or negative, branches each path of the radial biaxial, and gains a first constant A to one of them. Is added to one of the paths, the second constant B is given to the other path as a gain, and the axes are crossed to be connected to one path.
The control circuit for a rotating body is characterized in that the path from the axis to the second axis is connected so as to be added, and the path from the second axis to the first axis is connected to be subtracted.

According to the invention of claim 11, in claim 2, the complex coefficient transfer function is k (s + b-jω ₂ ) / (s + a
-Jω ₁ ), and when the angular frequencies ω ₁ and ω ₂ are arbitrarily selected, by setting b to zero or minute, and setting a small enough not to oscillate a, the phase across the bandwidth between the two angular frequencies is set. Is a filter circuit for controlling a rotating body characterized by sharply reversing.

[0022]

FIG. 1 is a diagram showing a filter circuit according to a first embodiment of the present invention. This is, for example,
A rotating body that is a supported body, electromagnets that control this rotating body in x and y2 axes that are orthogonal to the rotation axis, displacement sensors that measure the displacement in the respective axial directions, and power amplifiers that send drive signals to the electromagnets. In a magnetic bearing device equipped with, a biaxial displacement signal U = (U _x , U _y ) from a displacement sensor is input, and a biaxial control signal V = (V _x , V _y ) is supplied to a power amplifier. It is used as a filter circuit that constitutes a part of the output control circuit. This circuit is created based on the transfer function F ₁ (s) of the low-pass filter having the following first-order real number coefficient. F ₁ (s) ≡1 / (s + σ) (2)

The Laplace operator s of this transfer function F ₁ (s)
Is replaced by (s−jω), and the complex coefficient transfer function is represented by F (s−
jω), the input U is the complex coefficient transfer function F (s-j
ω), the output signals related to the x and y axes (the Laplace transform amounts thereof are Vx and Vy, respectively) are converted into one complex variable ( V = V
The transfer expression U · F (s−jω) = V (3) obtained by expressing with x + jVy is (U _x + jU _y ) / (s + σ−jω) = V _x + jV _y (4). Multiply both sides of the above equation by (s + σ-jω) to develop,
Corresponding the real part and the imaginary part, U _x −σV _x −ωV _y = sV _x (5) U _y −σV _y + ωV _x = sV _y (6)

When this is materialized, it becomes a filter circuit as shown in FIG. That is, an integrator 1 / s is provided in the signal path of each of the x and y axes, and negative feedback with a gain of σ, which is ½ of the passband width, is applied to each integrator 1 / s.
The following low pass filters are configured. Then, feedback is performed from each integrator so as to cross the x and y axes so that the feedback from the x axis to the y axis is positive and the feedback from the y axis to the x axis is negative. An angular frequency ω (which may be positive or negative) to be passed is inserted as a gain into these feedback paths, whereby the angular frequency component is selectively passed.

In this embodiment, ω = 3750 [rad /
FIG. 2 shows a Bode diagram when s] and σ = 7.5 [rad / s]. As a result, it is shown that the band including the central angular frequency regardless of positive or negative is passed with a sharp selectivity.

In the conventional biquad filter corresponding to the filter having the configuration of FIG. 1, V = {2zωs / (s ² + 2zωs + ω ² )} U (7) is given. z is a dimensionless number that gives the steepness of the filter, and corresponds to an attenuation ratio or a reciprocal of selectivity.
Equation (7) is a real number system and should be provided separately for the two axes x and y. FIG. 1 shows a specific block diagram thereof.
8 Integrators require a total of four for each two axes.
Further, when z is fixed, the slope of attenuation is constant in the Bode diagram, but when the horizontal axis is set to a linear scale, the steepness decreases in a high frequency region, and the bandwidth increases equivalently.

Therefore, in the case of using as a tracking filter, it is necessary to reduce z as the value of ω increases. In addition, since ω is a variable, ω in the figure needs to be a multiplier, and four of them are required, which increases cost or calculation time. Of course, Eq. (7) does not have a function of discriminating whether ω is positive or negative. On the other hand, the complex filter of FIG. 1 has the advantage that the bandwidth remains unchanged at σ, is simple and straightforward, requires about half the hardware, and digital control requires a short calculation time.

FIG. 3A shows a second embodiment of the present invention, which is a so-called notch filter that blocks only a specific frequency signal. The real coefficient transfer function which is the basis of this notch filter is F ₂ (s) ≡k (s + b) / (s + a), a>b> 0 (8). The complex coefficient transfer function calculates s of this denominator and (s−j
ω) is replaced by F ₂ (s−jω). The specific connection method is omitted because it is a special case where ω ₁ = ω ₂ = ω in F ₃ described later.

When this is materialized, it becomes a filter circuit as shown in FIG. That is, in the signal path of each axis,
A direct connection path having a gain of k is provided, and a low-pass filter (LPF) is provided in parallel with a branch therefrom. On the output side, 1/1 of the rejection bandwidth is obtained from the corner frequency a of the low-pass filter. Value obtained by subtracting b that is 2
There are provided a path for multiplying (ab) as a gain and returning to the direct connection path for subtraction coupling, and a crossing path for crossing the axes from the output of each low-pass filter and feeding back to the low-pass filter. . The low-pass filter is composed of an integrator and a feedback of the gain a as shown in FIG. In this crossing path, the angular frequency to be blocked is inserted as a gain, and at the connection point, the path from the x-axis to the y-axis is added, and the path from the y-axis to the x-axis is subtracted. I have. Thereby, as a result, the signal of the angular frequency component is canceled and the passage is prevented. This filter circuit can prevent the passage of only one of the positive and negative angular frequencies, and can compensate for maintaining a stable operation by giving an appropriate phase to the remaining signal. It should be noted that if b>a> 0, it becomes a pass filter, and if k = a / b, the bottom of the tail of the pass characteristic becomes 0.
dB. In the vicinity of the stop or pass band, only the phase change with almost no gain change (see FIG. 4) can be used for control.

FIG. 5 shows a third embodiment of the present invention, which is a combination of the first and second embodiments. Functionally, the above two filter circuits are connected in series. It works the same as if you let it work. That is, the positive or negative angular frequency component ω ₁ necessary for the configuration of the control signals in the two axis directions is passed,
It is a filter circuit for blocking other positive or negative angular frequency component ω ₂ .

This is based on the transfer function F ₃ ≡k (s + b) / (s + a) (9) when both denominators are first-order, and s of the denominator is (s-jω ₁ ), (s- jω
₂ ) The complex coefficient transfer function F ₃ ≡k (s + b−jω ₂ ) / (s + a−jω ₁ ) (10) is obtained. First, F ₃ = k {s + a-jω ₁ −a + b + j (ω ₁ −ω ₂ )} / (s + a−jω ₁ ) = k + k [{b−a + j (ω ₁ −ω ₂ )) by reducing the dimension of the numerator. } / (S + a−jω ₁ )] (11). Therefore, multiplying the input by k and passing it through,
It can be decomposed into a first-order lag element including the complex constant of the second term or a low-pass filter. Here, the configuration method of only the second term will be described.

[{B−a + j (ω ₁ −
input to ω ₂ )} / (s + a−jω ₁ )] U ₂ = ( U ₂ x + j U ₂ y)
If the output is V ₂ = V ₂ x + j V ₂ y, the real and imaginary parts of the complex equation after multiplying both sides by the denominator are equal, so that U ₂ x (b−a ) −U ₂ y (ω ₁ −ω ₂ ) = V ₂ x (s + a) + V ₂ yω ₁ (12) U ₂ x (ω ₁ −ω ₂ ) + U ₂ y (b−a) = V ₂ y (s + a) ) −V ₂ xω ₁ (13) is obtained, and from the equation (12), V ₂ x = [U ₂ x (ba) −U ₂ y (ω ₁ −ω ₂ ) −V ₂ yω ₁ ] / (s + a) (14) Similarly, from the equation (13), V ₂ y = [U ₂ x (ω ₁ −ω ₂ ) + U ₂ y (b−a) + V ₂ xω ₁ ] / (s + a) (15) is obtained. To be Multiplying the denominator by the conjugate of the denominator in equation (10) to make the denominator a real number is not desirable because it increases the number of components, increases the order of the system, and increases the calculation time in digital control. The connection according to the equations (14) and (15) is shown in FIG.
Is shown in the part other than the passage.

The signal path of each of the x and y axes is provided with a direct connection path having a gain of 1 and two parallel circuits branched from the direct connection path. One of the parallel circuits includes a low-pass filter LP connected to a half of the stop band and a rear part thereof.
An amount (ba) obtained by subtracting the corner frequency a of F is given as a gain, and this is input to the low-pass filter LPF. On the other hand, (ω ₁ −ω ₂ ) is given as a gain and connected to the input part of the low-pass filter LPF so as to cross it. The connections are such that the path from the first axis to the second axis is additive and the path from the second axis to the first is subtractive.

A circuit including the same low-pass filter LPF and cross-feedback of ω ₁ as in FIG. 3B constitutes a band-pass filter, which is the same as that described in FIG. It replaces ω with ω ₁ . That is, an integrator is provided in the signal path of each axis, and each of them is subjected to negative feedback with a which is ½ of the pass bandwidth. Then, from each integrator, x,
The feedback that intersects between the y-axes is performed so that the feedback from the x-axis to the y-axis is positive, and the feedback from the y-axis to the x-axis is negative. ₁ is inserted as gain. The output of the bandpass filter as a whole is summed and connected to a direct connection path.

This example is particularly effective when ω ₁ ≈ω ₂ . In other words, only the mode of ω ₁ is selected and ω ₂
This is the case when you do not want to touch the mode. a = b = 10 [r
FIG. 6 is a Bode diagram when ad / s], ω ₁ = 5000 [rad / s], and ω ₂ = 5100 [rad / s]. In spite of such close frequencies and considerable bandwidth, the gain difference between passing and blocking is about 40 [dB], demonstrating the effectiveness of this filter circuit.

FIG. 7 is an example for the purpose of delaying the phase angle of only a certain angular frequency band by 180 degrees in the circuit of FIG. 5 and not affecting the phases of other angular frequency regions. ω ₁ = 10000 [rad / s], ω ₂ = 40000 [rad / s
s], b = 0, a = 1 [rad / s], and a is sharply reversed over the bandwidth between the two angular frequencies by setting a so small that a does not oscillate. However, the gain characteristics are not completely flat. ω
_{If 1} and ω ₂ are reversed, the phase between them will be reversed by 180 degrees, and the slope of the gain will also be reversed.

Next, an example will be described in which a second-order low-pass filter having a real coefficient as a transfer function as shown in the following equation is used as a band-pass filter having a steep gain characteristic. F ₄ ≡ka ² / (s ² + 2zas + a ² ) (16) The z of this filter is usually called the damping ratio, and z <
Normally, it is set to 1 to make the bump near the break point thinner and higher to give resonance characteristics. However, in such a usage, the high-frequency side of the bump has a somewhat steep characteristic,
Since there is a defect that the bottom is shallow on the low frequency side, it is common to multiply the numerator of equation (16) by s, but the shape design of the bump is complicated (see FIG. 19).

According to the present invention, steep characteristics can be obtained even with a second-order filter, and not only the bandwidth but also the shape of the bump can be freely selected, and the positive / negative of the pass band can be freely selected. If s in Eq. (16) is replaced by (s-jω) in order to restore it with reference to any central angular frequency ω regardless of positive or negative, the relation with inputs U and V is obtained by multiplying both sides by a denominator containing complex numbers. , Ka ² U = {(s-jω) ² + 2za (s-jω) + a ² } V = {(s ² + 2zas + a ² −ω ² ) -j ² (ωs + zaω)} (Vx + jVy) (17) The real number of this equation Part and imaginary part are equal, {ka ² Ux−2 (ωs + zaω) Vy} / (s ² + 2zas + a ² −ω ² ) = Vx (18) {ka ² Uy + 2 (ωs + zaω) Vx} / (s ² + 2zas + a ² −ω ² ) = Vy (19) A circuit in which the denominator of the equations (18) and (19) is divided by ω ² to materialize is shown in FIG. However, k is omitted.

Both the x and y axes are secondary circuits.
It has extremely advanced functions and performance by crossing between them. Numerical examples are a = 250 [rad / s], ω = 5000 [rad /
FIG. 9 shows three Bode diagrams with z = 0.5, 0.707, and 1.0 in the case of [s]. However, the abscissa was a linear scale of angular frequency. The bandwidth can be given by 2a, z
Appropriate selection of ω s helps to improve the corners of the bandwidth. The gain characteristic becomes steeper as the bandwidth is smaller.

FIG. 10 shows still another embodiment of the present invention. A necessary angular frequency component or band is extracted from the input signal of the sensor output regardless of positive or negative, and the component or band is extracted. FIG. 6 is a block diagram of a control device that can be used to stabilize the component or band by giving a necessary phase angle and feedback, or to estimate other information necessary for control.

This includes a rotating body 1 which is a supported body, electromagnets 2a and 2b which control the rotating body in x and y2 axes which are orthogonal to the rotation axis, and displacement sensors which measure the displacement in the respective axial directions. In a magnetic bearing device provided with 3a and 3b and power amplifiers 4a to 4d (see FIG. 12) for sending a drive signal to an electromagnet, a biaxial displacement signal U =
Inputting (U _x , U _y ), the control signal V = (V _x ,
It is used as a control circuit that outputs V _y ) to a power amplifier. Since the electromagnets 2a and 2b can only attract, a pair of electrodes are provided so as to face each other with the shaft interposed therebetween, and control signals whose signs are opposite to each other are supplied to the pair.

In the figure, 5a, 5b, ... Denote the pass, block, or combined filters described in FIGS. 1 to 3, respectively, which pass different frequencies or remove nearby disturbing frequency components. To do. The complex gain circuits 6a, 6b ... Include the pass filters 5a, 5b ...
Are connected to each of, and as shown in FIG.
Each of the two radial axes is branched, a constant A is given as a gain to one side, and a constant B is given to the other path as a gain, and the axes are crossed and connected at the rear part of the A. At this connection point, the path from the x-axis to the y-axis is an addition, and the path from the y-axis to x
The paths to the axes are connected in a subtractive way.

The complex gain circuits 6a, 6b ...
At, the output phase can be increased or decreased by an arbitrary phase angle tan ^-1 [B / A] by arbitrarily selecting A and B. The gain at this time is (A ² +
B ² ) ^1/2 . 12 and 13 show a specific example of the control circuit having the above-described configuration, taking the control of the magnetic bearing as an example, and an example of the configuration of a closed loop system for stabilizing the magnetic bearing.

In FIG. 12, the pass filters 5a and 5b are provided.
Selects frequencies (+ ω and −ω in the example) and passes them. The complex gain circuits 6a and 6b have A ₁ = 0 and B ₁ = +
k ₊ , A ₂ = 0, B ₂ = −k ₋ are set, so that the frequency ω has a phase change of 90 degrees and the gain of k ₊ , and the frequency −ω has a phase change of −90 degrees. receive a gain of k _over. FIG. 13 shows the dynamic characteristics of the controlled object in the example of FIG.
It is a complex expression block diagram expressed as (s ² + ω ² ).

The action of the complex gain circuits 6a and 6b may be either advanced or delayed. Since the gain does not require dynamic characteristics, even if the phase is advanced, the gain does not increase unless both are increased while maintaining the ratio B / A. A plurality of such frequency (band) selection paths may be provided as necessary to provide a gain and a phase necessary for stabilization.

FIG. 14 shows a case where the object of control has the same dynamic characteristics as in FIG. 13 but produces a control force, for example, when the electromagnet has a first-order delay having a large time constant T, and the transfer function of this delay is 1 / (1 + Ts), and the + jω mode is sufficiently damped due to some influence, but only the −jω mode is underdamped. Therefore, in this case, only the -jω mode component is selected, and a constant complex gain
Give k and give feedback.

The Laplace transform of the equation of motion of the whole system including this feedback is s ² + ω ² = k / [(1 + Ts) (s + σ + jω)] (20) where k is an unknown complex number, and the characteristic equation of this system is F (s) = (s ² + ω ² ) (1 + Ts) (s + σ + jω)] − k = 0 (21) When Taylor expansion is performed near s = −jω, approximately F (s) | _{s = −j} ω = −2jωσ (1-jωT) (s + jω) −k (22), so the solution in the neighborhood is s = −jω + k / {-2jωσ (1-jωT)} (23)

Since the second term on the right side is an attenuation term, it is desirable that it is a negative real number. Therefore, if k = j (1-jωT) k (24), then s = -jω-k / 2ωσ (25) where k is a positive real number and corresponds to a normal feedback gain. Eventually, the expression (20) becomes s ² + ω ² = jk (1-jωT) / [(1 + Ts) (s + σ + jω)] (26). Here, (1-jωT) is newly added to the numerator in order to remove the influence of the first-order lag. The sensor output is set to x + jy, and the specific connection of the numerator excluding the selection filter is (x + jy) jk (1-jωT) = k [-y + xωT + j (x + yωT)] (27). Become. With such a configuration, in this control circuit, it is possible to provide damping by compensating the delay of the electromagnet by passing only -ω of ± ω by the selection filter.

FIG. 15 shows an example in which the present invention is applied to a tracking filter. The tracking filter is used, for example, to extract a rotation synchronization component and remove a vibration component close to it including a rotation speed, or to increase bearing rigidity only near the rotation speed. In the tracking filter of the present invention, in the pass filter described in FIG. 1, ω that is cross-feedback is not a constant but a variable. That is, the output from the integrator is multiplied as a variable by the signal from the sensors 3a and 3b or the voltage signal corresponding to the rotation speed generated from the sensor dedicated to the rotation speed detection. Further, σ fed back from the output of the integrator is 1/2 of the pass band width, and plays the role of preventing the oscillation of the selective path at the same time as the operation of the low pass filter. If .sigma. is suppressed to a level that includes an error in voltage generation corresponding to the rotation speed, unnecessary signals such as noise other than the rotation synchronization signal become small.

[0050]

According to the filter circuit for controlling a rotating body of the present invention, it is possible to separate two vibration modes of opposite signs, which have the same absolute value or are extremely close to each other, which exist in the flexible mode of the rotating body, It is possible to select only one mode and estimate its state quantity or apply a predetermined control law. Therefore, it is possible to perform the control suitable for the operating condition of the rotating body with a relatively simple device or software, and to enable the stable operation of the rotating body supported by the magnetic bearing or the like. Further, in the rotating body control circuit of the present invention,
It becomes possible to simultaneously adjust the gain and the phase, which have been impossible with the conventional method, regardless of the frequency, and thereby, control suitable for the operating condition of the rotating body can be performed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 is a graph showing characteristics of the circuit according to the embodiment of FIG. 1;

FIG. 3 is a block diagram showing a second embodiment of the present invention.

FIG. 4 is a graph showing characteristics of the circuit according to the embodiment of FIG. 3;

FIG. 5 is a block diagram showing a third embodiment of the present invention.

FIG. 6 is a graph showing characteristics of the circuit according to the embodiment of FIG. 5;

FIG. 7 is a graph showing characteristics of another example in which the constant is changed in the circuit of the embodiment of FIG.

FIG. 8 is a block diagram showing a fourth embodiment of the present invention.

FIG. 9 is a graph showing characteristics of the circuit according to the embodiment of FIG. 8;

FIG. 10 is a block diagram of a control device using a control circuit for a rotating body according to an embodiment of the present invention.

FIG. 11 is a block diagram for realizing a complex gain according to another embodiment of the present invention.

FIG. 12 is a block diagram of a control device using a control circuit for a rotating body according to another embodiment of the present invention.

13 is a block diagram showing a transfer function of the control circuit of FIG.

FIG. 14 is a block diagram of a control device using a control circuit for a rotating body according to another embodiment of the present invention.

FIG. 15 is a block diagram of a tracking filter of the present invention.

FIG. 16 is a graph showing characteristics of a conventional filter circuit.

FIG. 17 is a diagram illustrating characteristics of the filter circuit of the present invention.

FIG. 18 is a diagram showing a conventional filter circuit.

FIG. 19 is a graph showing characteristics of a conventional second-order filter circuit.

[Explanation of symbols]

 1 Rotating body 2a, 2b Electromagnet 3a, 3b Displacement sensor 4a, 4b, 4c, 4d Power amplifier 5a, 5b Filter 6a, 6b Complex gain circuit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H03H 17/02 633 9274-5J H03H 17/02 633A

Claims (11)

[Claims] 1. In a system for controlling two radial axes (x, y axes) orthogonal to the rotation axis (z axis) of a rotating body by electromagnetic force or the like, input signals related to the x, y axes (the Laplace conversion amount thereof). Is expressed as a single complex variable ( U = Ux + jUy), and the transfer function of the low-pass or high-pass filter with real coefficients is F (s), and the central angular frequency of positive or negative to pass or block is ω, The imaginary unit is j, and the transfer function F (s) is
The x, y-axis of the Laplace operator s of the complex coefficient transfer function is replaced with (s-j [omega]) and F (s-jω), the input U has passed the complex-coefficient transfer function F (s-jω) In the transfer expression U · F (s−jω) = V obtained by expressing the related output signals (the Laplace transform amounts thereof are Vx and Vy, respectively) by one complex variable ( V = Vx + jVy), F (s− A filter circuit for controlling a rotating body, characterized in that, after multiplying both sides of the expression by the denominator of (jω), the transfer expression is connected by a transfer element having a real number coefficient so that the real part and the imaginary part are equal to each other. 2. A component including positive and negative central angular frequencies to be passed and blocked, ω ₁ and ω ₂ , respectively, and ω ₁ ≠ ω ₂ , including a bandwidth (2a) before and after ω ₁ as a center. before and after the bandwidth centered on omega ₂ with passing (2
In order to prevent the components including b), k is an arbitrary gain or coefficient, z is an arbitrary dimensionless number, and the complex coefficient transfer function is k (s + b−jω ₂ ) / (s + a−jω ₁ ). Alternatively, k (s + b−jω ₂ ) / {(s−jω ₁ ) ² + 2za (s−jω ₁ ) +
The filter circuit for controlling a rotating body according to claim 1, wherein the filter circuit is given in the form of a ² }. 3. In the numerator and / or denominator of the transfer function F (s) in claim 1, k is an arbitrary gain or coefficient, and 2a is a pass or stop bandwidth centered on the central angular frequency. Including a quadratic system represented by k (s ² + 2zas + a ² ), replacing s by (s−jω), and arbitrarily selecting the dimensionless number z, the bandwidth of the gain characteristic of the frequency characteristic of the filter The filter circuit for controlling a rotating body according to claim 1, wherein the vicinity of the break points at both ends is made closer to the ideal filter. 4. A combination of a plurality of rotator control filter circuits according to any one of claims 1 to 3 to pass or block a specific band among all frequency bands including a negative frequency region. A filter circuit for controlling a rotating body characterized by the above. 5. The rotating body control filter circuit according to claim 1, wherein ω, ω ₁ and ω ₂ are not constants, and each instantaneous value is input as a variable. Tracking filter. 6. In a system for controlling radial two axes (x, y axes) orthogonal to the rotation axis (z axis) of a rotating body by electromagnetic force or the like, an angular frequency component or It is composed of a filter part for extracting a band component and a part for giving a necessary phase angle to the extracted component, and the output passing through both parts is used for estimating another state quantity necessary for control, or A control circuit of a rotating body for stabilizing the mode of the extracted component by feeding back, and the portion that gives the phase angle is A + j where A and B are real constants.
B≡ F c is the complex gain circuit represented by, the F c the x, y
Between input (Ux, Uy) and output (Vx, Vy) to the shaft, Vx ＝
Connect so that AUx-BUy, Vy = BUx + AUy, A,
By arbitrarily selecting B, the phase of the output can be increased or decreased by an arbitrary phase angle regardless of the input frequency, and any necessary phase angle can be obtained only in the frequency region necessary for estimating the control or the control-related signal. A control circuit for a rotating body, characterized in that 7. A system for controlling radial 2 axes orthogonal to the rotation axis of a rotating body by electromagnetic force or the like, inputs a signal related to the radial 2 axis directions, and outputs a positive or negative signal required for the configuration of the control signals in the 2 axis directions. A rotary body control filter circuit for extracting a negative angular frequency component, wherein an integrator is provided in a signal path of each axis, and negative feedback with a gain of 1/2 of a pass band width is applied to each of the integrators. , Feedback from each integrator crossing the axes is performed such that the feedback from the first axis to the second axis is positive, and the feedback from the second axis to the first axis is negative,
A filter circuit for controlling a rotating body, wherein a center angular frequency to be passed is inserted as a gain into both of the feedback paths to selectively pass the angular frequency component. 8. In a system for controlling radial two axes orthogonal to the rotation axis of a rotating body by electromagnetic force or the like, a signal related to the radial two axis directions is input and the positive or A rotary body control filter circuit for blocking or passing a negative angular frequency component, wherein a direct connection path having a gain of 1 is provided in a signal path of each axis, and a primary low-pass filter is provided in parallel from the direct connection path. The output is multiplied by a value obtained by subtracting 1/2 of the stop band width of the low pass filter from the stop band width or the tail band width (difference of the outer side corner angle frequency) in the case of passing, and the direct connection is obtained. A path is provided for returning to the path and performing subtractive coupling, and crossing the axes from the output of each low-pass filter to feed back to the low-pass filter, and inserting the center angular frequency to be blocked as a gain in the path. However, at the connection point, the paths from the first axis to the second axis are combined so as to be added, and the paths from the second axis to the first axis are combined so as to be subtracted, and blocking or passing around the central angular frequency is performed. A filter circuit for controlling a rotating body, characterized in that a signal of a bandwidth component is blocked or passed. 9. A system for controlling a radial two-axis orthogonal to a rotation axis of a rotating body by electromagnetic force or the like, inputs a signal related to the radial two-axis direction, and a positive or A rotary body control filter circuit for allowing a negative angular frequency component ω ₁ to pass and blocking other positive or negative angular frequency component ω ₂ , wherein a direct connection path having a gain of 1 is provided in a signal path of each axis. Two parallel circuits are provided by branching from each of them, and one of the two parallel circuits has an angular frequency of 1/2 of the stop band width and a corner frequency of a first-order low-pass filter connected to the rear part thereof. A gain obtained by subtracting 1/2 of a certain pass band width is given as an input to the low-pass filter, and ω ₁ −ω ₂ is given as a gain to the other parallel circuit, and the connection is made to the input part of the low-pass filter. Cross to connect and connect In terms of points, the paths from the first axis to the second axis are combined so that the paths from the second axis to the first are subtractive, and one of the outputs of the low-pass filter is additively connected to the direct connection path, The other output is cross-feedback between the axes to the input part of the low-pass filter to give ω ₁ as a gain,
At the connection point at the input part, the paths from the first axis to the second axis are combined so that the paths are added and the paths from the second axis to the first axis are subtracted, and the bandwidth in the vicinity around ω ₁ is A filter circuit for controlling a rotating body, characterized in that it is configured to pass through and to block a bandwidth around ω ₂ . 10. A radial 2 orthogonal to the axis of rotation of the rotating body.
In a system for controlling an axis by an electromagnetic force or the like, a control circuit for inputting a signal related to a radial two-axis direction and outputting a control signal in the two-axis direction. The frequency component or band is extracted, each path of the radial two axes is branched, the first constant A is given to one of them as a gain and added to one path, and the second constant B is taken to the other path as a gain. It is connected to one path by crossing between the axes, and at the connection point, the first axis to the second axis are connected.
A control circuit for a rotating body, wherein the path to the axis is connected so as to be added, and the path from the second axis to the first axis is connected to be subtracted. 11. The complex coefficient transfer function according to claim 2, which is given by k (s + b−jω ₂ ) / (s + a−jω ₁ ), and when the angular frequencies ω ₁ and ω ₂ are arbitrarily selected, b A filter circuit for controlling a rotating body, characterized in that the phase is sharply reversed over the bandwidth between the angular frequencies by setting 0 to 0 or a small value so that a does not oscillate.