JPH05122970A - Motor speed controller - Google Patents

Abstract

(57) [Abstract] [Purpose] High accuracy of disturbance torque estimation is maintained even if the motor current control loop is omitted, and high frequency and unspecified low frequency speed fluctuations are suppressed simultaneously with a simple configuration. [Construction] The observer type torque disturbance compensating means 30 is provided in the motor speed control device of the voltage control loop, and the disturbance torque estimated value correcting means 35 is provided, and the disturbance torque is calculated by multiplying the speed detection value by a constant gain. Correct the estimated value,
Eliminate the effects of induced voltage constants and / or viscosities that are not reflected in the voltage control loop. Further, if the ratio of the speed fluctuations when the disturbance torque compensating means 30 having a filter is provided in the output part is provided and when it is not provided, and the filter function is F (s), then Rv = 1-F (s). Utilizing the fact that a simple relationship holds, the characteristics of the filter are set to those that simultaneously suppress velocity fluctuations of a specific high frequency and an unspecified low frequency.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speed control device for an information recording / reproducing head of an information recording / reproducing device and a motor for driving an information recording medium. The information recording / reproducing apparatus includes a video tape recorder (VTR), a video camera, a data streamer, a magneto-optical disk, a facsimile, etc., the information recording / reproducing head includes a magnetic head, an optical head, etc., and the information recording medium is a magnetic tape. , Optical / magnetic disks, recording paper, etc.

[0002]

2. Description of the Related Art It is known that in an apparatus having a portion for driving a head or a recording medium to be driven by a motor as described above, image quality and sound quality are deteriorated when the relative speed between the head and the recording medium fluctuates. .. On the other hand, the rotation speed of the motor fluctuates due to torque fluctuations due to the torque ripple of the motor and unpredictable disturbances. Therefore, conventionally, various methods have been proposed for suppressing fluctuations in motor speed due to torque disturbance and the like.

One of the methods is the 1990 INTERNATIONAL POWER ELECTRONICS CONFERENC.
The disturbance observer method discussed on pages 450 to 456 of the proceedings of E) is typical. In this method, first, a torque generated by a motor for a given current command is estimated by a motor torque model that simulates a characteristic relationship between a motor current command corresponding to a speed command and a torque generated by the motor. On the other hand, the generation of the motor corresponding to the detected speed of the motor or load is performed by the load torque inverse model that simulates the characteristic relationship between the detected speed of the motor or the detected speed of the load such as magnetic tape or rotating cylinder and the generated torque of the motor Estimate the torque. Then, the difference between the estimated values of the generated torque of the motor obtained by these two models is obtained as the disturbance torque, and the current command is corrected so as to cancel the obtained disturbance torque. This theoretically eliminates the effect of torque disturbance on the motor speed output.

Another method is disclosed in Japanese Patent Laid-Open No. 61-240871.
As described in the publication, many attempts have been made to remove the speed fluctuation of the motor caused by torque disturbance or the like by learning control. That is, the periodic fluctuation pattern included in the speed fluctuation is distributed over a plurality of rotations of the motor by a random access memory (RAM: RandomAcce).
ss Memory) and the like, and creates a correction signal that cancels the fluctuation pattern to reduce the motor speed fluctuation.

[0005]

The disturbance observer system described above is premised on having a current control loop in addition to the speed control loop in order to achieve highly accurate control.

However, in recent years, the size and weight of equipment has been reduced,
With the demand for lower prices, it has become necessary to omit the current control loop, which is not necessarily essential for speed control.

However, in the speed control of the motor, if the current control loop is omitted, the internal induced voltage and the viscous resistance of the motor to be controlled will directly affect the control system. In other words, the internal induced voltage and viscous resistance of the motor change according to the rotation speed of the motor, but since their effects are reflected in the motor current, it is possible to eliminate those effects with a current control loop. This is because if the current control loop is omitted, its action disappears.

In the case of the disturbance observer system described above, relatively low frequency velocity fluctuations can be suppressed, but due to observation noise (sampling noise), control delay, etc.,
It has become clear that it has little effect on high-frequency velocity fluctuations.

On the other hand, according to the above-mentioned other method, there is a problem that it is possible to cope with a relatively high frequency with respect to a periodic fluctuation, but it is not possible to cope with a fluctuation whose frequency is not specified. Moreover, the detection means for detecting the amplitude and phase of the rotation fluctuation, the means for creating the correction signal based on the detected fluctuation pattern, and the RAM are required, so that the circuit configuration of the torque fluctuation compensating means becomes complicated. Becomes
There is a problem that it becomes a factor of cost increase.

A first object of the present invention is to provide a motor speed control device which improves the accuracy of disturbance torque estimation by a disturbance observer in a speed control loop which does not include a current control loop.

A second object of the present invention is to provide a motor speed control device having a simple structure capable of simultaneously suppressing a speed fluctuation of a relatively high frequency and a speed fluctuation of a low frequency of an unspecified frequency. ..

A third object of the present invention is to provide a motor speed control device which can achieve the above first and second objects at the same time.

[0013]

To achieve the first object, the motor speed control device of the present invention adjusts the voltage command value of the motor so that the detected speed value of the motor coincides with the speed command value. Speed control means, motor drive means for controlling the input voltage of the motor based on the voltage command value, the voltage command value and the speed detection value are input, and the motor and the load of the motor are simulated. In the motor speed control device, the estimated value of the torque disturbance is obtained based on the model, and the torque detected value is corrected by the disturbance torque compensating unit that corrects the voltage command value so as to cancel the estimated torque disturbance value. Disturbance torque estimated value correction means for inputting and correcting the torque disturbance estimated value according to the detected speed value is provided.

In this case, the torque disturbance estimated value correction means has a proportional element for multiplying the speed detection value by a constant value, and the output of the proportional element is added to or subtracted from the disturbance torque estimated value. can do. Further, the gain of the proportional element is a value obtained by dividing the product of the torque constant of the motor and the induced voltage constant by the coil resistance value of the motor, or a viscosity constant of the motor and the load is added to the value. It is preferable to set the value.

In order to achieve the second object, the motor speed control device of the present invention comprises speed control means for adjusting the motor control amount command value so that the motor speed detection value matches the speed command value. A motor driving means for controlling the input control amount of the motor based on the control amount command value, and a model in which the control amount command value and the speed detection value are input to simulate the motor and the load of the motor. Disturbance torque for obtaining an estimated value of the torque disturbance based on the above, obtaining a correction value of the control amount command value so as to cancel the estimated torque disturbance value, and correcting the control amount command value with a value obtained by filtering the correction value. In a motor speed control device including a compensating means, a transfer function for the filtering process is a transfer function of a high-pass filter of a first order or higher, a torque ripple of the motor and a power source noise. Characterized by comprising set a transfer function obtained by multiplying the transfer function to reduce the gain of at least one frequency or frequency band's function obtained by subtracting from 1.

Further, the filtering means has a transfer function obtained by subtracting a product of transfer functions of a high-pass filter of a first order or higher and a notch filter from 1, and the transfer function of the notch filter is a torque ripple of the motor. It can be configured by setting a transfer function that reduces the gain of at least one frequency or frequency band of power supply noise.

The third object can be achieved by including both the disturbance torque estimated value correction means and the filter processing.

[0018]

With this structure, the object of the present invention can be achieved by the following operation according to the present invention.

The influence of the internal induced voltage of the motor and the viscous resistance on the torque can be basically approximated by a linear function of the rotation speed of the motor. Therefore, by correcting the disturbance torque estimated value according to the detected speed value of the motor, it is possible to estimate the disturbance torque that cancels out these influences. As a result, even if the current control loop is omitted in the disturbance observer method, the speed control can be realized with high accuracy by the correction means having a simple structure, and it can be applied to the motor control of the information recording / reproducing apparatus to improve the image quality and sound quality. Can be prevented or the reliability of the data streamer can be prevented from decreasing.

Further, by utilizing the fact that there is a simple relationship between the filter characteristic and the speed fluctuation ratio, the transfer function related to the filtering process is the transfer function of the high-pass filter of the first or higher order and the torque ripple of the motor. Since the transfer function obtained by multiplying the transfer function that reduces the gain of at least one frequency or frequency band of power supply noise is set to a function that is subtracted from 1, it is difficult to apply the conventional speed fluctuation at low frequency. Both regular frequency fluctuations of high frequency can be effectively suppressed.

Further, by providing the disturbance torque compensating means and processing the disturbance torque correction value through the filter having the above-mentioned filter characteristic, even in the disturbance observer system in which the current control loop is omitted, the internal induced voltage of the motor or It is possible to remove the influence of viscosity and suppress a specific high frequency speed fluctuation such as torque ripple with a simple configuration.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to illustrated embodiments. FIG. 1 shows a block diagram of a main part of a motor speed control device according to an embodiment of the present invention. Motor 1 as shown
1 is connected to a load 12 such as a magnetic tape running device, and the rotation speed of the motor 11 (or load 12) is detected by a speed detector 13. The speed detection value ω of the motor detected by the speed detector 13 is matched with the speed command value ωc by the adding means 21, and the deviation thereof is the speed control means 2
Entered in 2. The speed detection means 22 outputs a voltage command value Vc that cancels the input speed deviation as a control amount command value for the motor 11. The speed control means 22
Has a phase delay compensation function that has a large gain in the low frequency range and a small gain in the high frequency range. The voltage command value Vc is added to a disturbance torque correction value Vcomp, which will be described later, in the adding means 23, and is input to the motor driver 24 as a final voltage command value Vin. The motor driver 24 controls the voltage supplied to the motor 11 according to the input voltage command value Vin.

The disturbance torque compensating means 30 is basically a so-called disturbance observer type disturbance torque compensating means, and includes a motor torque model 31, a load torque inverse model 32, and
Motor torque inverse model 33 and low-pass filter 34
And a disturbance torque estimated value correction means 35, which is a characteristic part of the present embodiment. Motor torque model 31
Is a simulated characteristic function for estimating the motor torque generated when the motor 11 is driven according to the voltage command value Vin. The load torque inverse model 32 includes a motor 11 and a load 12
Is a simulated characteristic function for estimating the input torque of the mechanical system consisting of The difference between the estimated torque values corresponds to the disturbance torque, and the addition means 36 obtains the estimated disturbance torque value. Motor torque reverse model 3
3 is to convert the dimension of the torque into the dimension of the voltage command value. Speed control means 22 and disturbance torque compensation means 30
Can be configured using a microcomputer.

Now, the detailed configuration of the disturbance torque compensating means 30 will be described with reference to the disturbance torque estimated value correcting means 35, which is a feature of this embodiment, with reference to the block diagram shown in FIG. In FIG. 2, the blocks corresponding to the blocks in FIG. 1 or the components are indicated by the same reference numerals. The description of the motor driver 24 is omitted because it can be ignored in terms of transfer function. Block 101 in the figure
Is a portion corresponding to the block diagram of the motor 11 and the load 12. Here, as the motor 11, a small brushless motor widely used in an information recording / reproducing apparatus is shown as an example. This motor shall have negligible coil inductance and shall not have a current control loop. As shown in the figure, among the blocks constituting the block 101, the block 111 is the voltage conversion amount of the torque constant of the motor 11, and the block 112 is the motor 11
And the transfer function of the motor / load characteristic composed of the moment of inertia J of the load 12 and the viscosity constant B. The block 113 represents the internal induced voltage of the motor 11 by a constant. Further, all disturbances are represented as acting as disturbance torque τD.

The function of the motor torque model 31 corresponds to the model of the block 111, and the estimated torque 38 generated by the motor 11 is obtained from the voltage command value Vin. In the model 31, the nominal value KTnom of the torque constant described in the catalog of the motor 11 in place of the torque constant KTnom (subscript nom is the nominal value n
The same applies hereinafter). Rc represents the electric resistance of the motor coil. The load torque inverse model 32 corresponds to the inverse model of the block 112, and calculates the input torque estimated value 39 of the load system including the motor 11 and the load 12 from the detected speed value ω. Further, as the inertia moment J of the motor 11 and the load 12, its nominal value Jnom is used. In this example, the viscosity constant B is small and is ignored. These models 3
The difference 40 between the estimated torque values estimated by 1 and 32 is obtained by the adding means 36, and this corresponds to the basic disturbance torque τD.

The disturbance torque estimated value correction means 35 is a characteristic part of the present invention, and can be represented as a proportional element of the gain kcomp, as will be described later. The disturbance torque estimated value correcting means 35 receives the speed detection value ω as an input, obtains a disturbance torque estimated value correction value 41, and outputs it to the adding means 37.
The motor torque inverse model 33 is a conversion gain for converting the estimated torque value τDint corrected by the adding means 37 into a dimension of the voltage command value, and is an inverse function of the motor torque model as shown in the figure. The low-pass filter 34 is provided to reduce the influence of noise and sampling of sampling control.

Now, the operation of the embodiment constructed as described above and the details of the disturbance torque estimated value correction means 35 will be described. For simplicity, the operation of the low-pass filter 34 for removing noise will be omitted here. As described above, the conventional disturbance observer is provided with the current control loop and is based on the premise that the control command is the current.
The torque generated by the motor 11 can be directly controlled by the current control loop. Therefore, it is not necessary to consider the influence of the internal induced voltage of the motor 11 and the viscosity related to the motion of the load system, and it is not necessary to provide the disturbance torque estimated value correction means 35 as in the present embodiment. However, there is a demand for omitting the current control loop even in a device that requires high-accuracy speed control due to the demand for smaller size and lighter weight and the demand for lower price. Therefore, the present invention realizes a disturbance observer which is provided with the disturbance torque estimated value correction means 35 and can eliminate the influence of the internal induced voltage and viscosity of the motor even if the current control loop is omitted. Hereinafter, this will be described in detail.

In order to return to the principle of the disturbance observer and to consider its function, the disturbance torque compensating means 30 of FIG. 2 is divided into the disturbance torque estimating means 102 and the correction signal generating means 103 as shown in FIG. First, the correction value V of the voltage command value
The correction signal creating means 103 is derived from the relationship between comp and the disturbance torque τD.

The relationship of equation 1 is established among the voltage command value Vc, its correction value Vcomp, the disturbance torque τD, and the speed detection value ω.

[0030]

[Equation 1]

In order that the detected speed value ω, that is, the rotation speed of the motor becomes independent of the disturbance torque τD, the correction value Vc
It suffices if omp can be expressed as in Equation 2.

[0032]

[Equation 2]

Here, the torque constant of equation 2 is given by its nominal value K.
When Tnom is used and the estimated value τDinf is used as the disturbance torque, the correction value Vcomp can be expressed as in Equation 3.

[0034]

[Equation 3]

Therefore, the correction signal generating means 103 can be expressed as in the equation 4 by using the torque constant nominal value KTnom and the coil resistance RC.

[0036]

[Equation 4]

Next, the disturbance torque estimating means 102 will be derived.

First, the motor input voltage Vin and the disturbance torque τ
The relationship shown in Formula 5 is established between D and the detected speed value ω.

[0039]

[Equation 5]

When the equation 5 is transformed, the disturbance torque τD is given by the equation 6
become that way.

[0041]

[Equation 6]

Therefore, the estimated disturbance torque value τDinf is the motor input voltage Vin, the detected speed value ω, and the torque constant nominal value KTn.
om, coil resistance Rc, nominal value Jnom of inertia moment of motor and load, nominal value Bnom of viscous constant, and induced voltage constant nominal value KEnom can be used to express as in Equation 7.

[0043]

[Equation 7]

From the equations (4) and (7), in the motor control device which does not have the current control loop, the disturbance observer is designed so that the detected speed value ω, that is, the rotation speed of the motor becomes independent of the disturbance torque τD. It can be understood that the disturbance torque compensating means 30 having the structure as shown in FIG. Further, the gain kcomp of the disturbance torque estimated value correction means 35 is expressed as in Eq.

[0045]

[Equation 8]

Thus, the disturbance torque estimated value correction means 3
By setting 5, the influence of the internal induced voltage of the motor and the viscosity can be eliminated to realize a disturbance observer that can suppress the influence of the disturbance torque τD.

Further, when the motor 11 is a control object such as a small brushless motor whose viscosity constant B is so small that it can be ignored, the gain of the disturbance torque estimated value correcting means 35 may be set as shown in Formula 9. Absent.

[0048]

[Equation 9]

Here, the disturbance torque suppressing effect according to the present embodiment will be described in comparison with the prior art. Here, the prior art has a configuration in which the disturbance torque estimated value correction means 35 is not provided in FIG. Note that the effect of viscous resistance was ignored for simplicity. In addition, a low pass filter 3 for removing noise
4 has a first-order lag characteristic, and its cutoff frequency is ωf.

In the present embodiment of FIG. 2, the relationship between the disturbance torque τD and the speed detection value ω when the command voltage Vc is 0 can be expressed by the following equation.

[0051]

[Equation 10]

Similarly, in the case of the conventional example, the relationship between the disturbance torque τD and the detected speed value ω when the command voltage Vc is 0 can be expressed by the following equation.

[0053]

[Equation 11]

Here, the effect of the disturbance torque estimated value correction means 35 will be trial calculated from the above equation. The specific control parameters are set as shown in Table 1. Further, for simplicity, it is assumed that the nominal value of the control parameter matches the actual value.

[0055]

[Table 1]

Under the above conditions, the disturbance torque τD is shown in FIG.
The relationship of the speed detection value ω with respect to is represented by frequency on the horizontal axis and gain on the vertical axis. In the figure, the solid line L1 is the gain characteristic of the speed fluctuation with respect to the disturbance torque of the present embodiment, the dotted line L2 is the characteristic of the conventional example, and the dotted line L3 is the characteristic of the motor alone without the disturbance observer. From the figure, it can be seen that the disturbance torque suppression effect is increased particularly in the low frequency region by providing the disturbance torque estimated value correction means 35.

As described above, the present invention can improve the performance of the disturbance observer by considering the influence of the internal induced voltage of the motor and the viscous resistance. According to the present invention, this makes it possible to configure a control system that is effective even for a control target that does not have a current control loop, which has hitherto been difficult to apply a disturbance observer.

Therefore, according to the method of the present invention, the current control loop which has been required for precise control can be omitted.
While satisfying the requirements for precise control, it is possible to reduce the size, weight and cost of the equipment.

Further, since the accuracy of the motor to which the speed command is given by the voltage can be dramatically improved, the image quality of the VTR, the facsimile and the handy copy device can be improved, and the reliability of the auxiliary recording device of the information equipment can be improved.

Next, with reference to FIG. 5, an embodiment of the present invention will be described in which the speed fluctuation of a relatively high frequency and the speed fluctuation of a low frequency of an unspecified frequency can be simultaneously suppressed. FIG. 5 is a block diagram showing the control configuration of the main part of this embodiment, and as shown in the figure, the disturbance torque is compensated by the observer system as in the embodiment of FIG. 1 or 2. Further, basically, it is also applicable to a device having both a voltage control loop and a current control loop, and a device in which the current control loop is omitted. The present embodiment is characterized in that the characteristic of the filter is set using a relational expression established between the filter characteristic in the disturbance observer and the speed fluctuation characteristic with respect to the disturbance torque. As a result, it is possible to set the speed fluctuation characteristic according to the device to be controlled, and it is possible to realize a VTR with higher sound quality and higher image quality than before, a highly reliable data streamer, and the like. Hereinafter, description will be given with reference to the drawings. In FIG.
A block 200 represents a motor and a load to be controlled by modeling, and the disturbance is added as a disturbance torque τ. Further, a block 220 indicates a disturbance torque compensating means of a disturbance observer system. In the block 200, a block 201 is a motor torque constant KT, a block 202 is a block modeling the influence of the inertia moment of the motor and the load on the control system, and the transfer function 1
/ Js A block 221 is a nominal value KTnom of the torque constant of the motor, and a block 222 is a load torque inverse model of the influence of the inertia moment of the motor and the load on the control system. Similar to the FIG. 2 embodiment, blocks 221 and 222
The difference between the motor generated torque and the load input torque estimated values 224 and 225 respectively estimated by
The disturbance torque estimation value τinf can be obtained as. A block 226 is a gain for converting the disturbance torque estimated value τ inf into the dimension of the control amount command value u input to the motor, and is a reciprocal of the nominal value of the motor torque constant. Block 22
The estimated disturbance torque value passing 6 is the correction value u of the control amount command value.
It becomes ´comp. A block 227 is a characteristic part of this embodiment, and is set in a filter characteristic F (s) described later.
Here, the velocity fluctuation of the relatively high frequency and the velocity fluctuation of the low frequency of the unspecified frequency included in the correction value u'comp are reduced to the correction value ucomp. This correction value is added by the addition means 23.
At 0, it is added to the control amount command value u and acts to remove the disturbance torque τ. The control amount command value u may be a voltage command value, a current command value, or the like. Note that the speed fluctuation used in the following description is equivalent to the fluctuation of the rotation speed (speed detection value) ω, and unless otherwise specified, the rotation speed and the speed fluctuation are treated without distinction.

Next, the filter characteristic of the block 227 will be described. In general, a control device using a disturbance observer includes a first-order low-pass filter for compensating for noise and operation delay inside the observer. As a result, the sensitivity in the high frequency region is reduced and the overall stability is secured.

In addition to such a characteristic, the filter characteristic of the present embodiment is intended to have a velocity fluctuation reducing characteristic not present in the conventional disturbance observer, by locally changing the filter sensitivity at a specific frequency. It is a thing. The squid,
The mechanism will be described.

In FIG. 5, the disturbance torque compensating means 220
The velocity fluctuation vnull with respect to the disturbance torque τ in the case where does not exist, ignores the manipulated variable uin from the block diagram,
It can be expressed as Equation 12.

[0064]

[Equation 12]

On the other hand, when the disturbance torque compensating means 220 is provided, the velocity fluctuation vobs with respect to the disturbance torque τ can be obtained by solving the equations (13) and (14) below.

[0066]

[Equation 13]

[0067]

[Equation 14]

That is, from the equations 13 and 14, the velocity fluctuation vob
s is as shown in Expression 15.

[0069]

[Equation 15]

Now suppose that all nominal values such as KTnom are equal to the actual values of their corresponding parameters,
If the speed variation ratio Rv at this time is defined by vobs / vnull and the controlled variable uin is ignored, the speed variation ratio Rv becomes the following relational expression (16).

[0071]

[Equation 16]

As is apparent from this, the speed fluctuation ratio Rv
Will be determined only by the filter characteristic, and the speed fluctuation can be easily suppressed by setting the filter characteristic.

Here, the characteristic setting of the filter block 227 of the disturbance torque compensating means 220 will be described based on the above relationship. As a specific example of the controlled object, consider a capstan motor speed control system of a video movie. Since a motor for a video movie requires highly accurate control characteristics, a three-phase brushless motor is generally used. Now, assume that the motor structure is 8 poles and 6 coils, and the rotation speed is constant and 2.28 Hz. At this time, the motor adjusts to about 54.5H according to the sinusoidal fluctuation of the magnetic field flux.
Generates z torque ripple. This torque ripple causes a fluctuation in the speed of the tape and deteriorates the image quality. On the other hand, when the control calculation based on the sampling control is performed every 1.39 ms, the experimental limit value of the disturbance observer is about 20 Hz. Therefore, in the conventional disturbance observer system,
The 54.5 Hz torque ripple cannot be removed.

Therefore, in the present invention, the effect of suppressing velocity fluctuations at low frequencies may be the same as that of the conventional disturbance observer.
It is intended to suppress the speed fluctuation due to the torque ripple of the motor by setting the filter characteristic so as to show the large speed fluctuation suppressing effect only in the torque ripple frequency or band. By the way, in the case of a capstan motor, since the rotation speed is constant during recording and reproduction,
Torque ripple occurs at a constant frequency. Therefore,
It is considered that a disturbance observer that can be applied to a constant high torque ripple frequency can be realized by the filter characteristics without adversely affecting the stability.

Now, when a primary low-pass filter is used as the filter, it can be seen from equation 16 that the speed fluctuation ratio Rv exhibits a primary high-pass filter characteristic by simple calculation. Therefore, if the speed variation ratio Rv is set to a characteristic in which the primary high-pass filter and the notch filter are combined as shown in FIGS. 6A and 6B, the above condition is satisfied.
When this is expressed by a mathematical expression, it becomes as shown in Expression 17.

[0076]

[Equation 17]

Here, ωc is the cutoff frequency of the high-pass filter, ωn is the notch frequency, and ζ is the damping constant. Here, ωc = 10.0 (Hz), ωn = 54.5 (Hz), ζ = 0.06
I am trying.

From Eqs. 16 and 17, the filter characteristics to be obtained can be expressed as Eq.

[0079]

[Equation 18]

FIGS. 3 (a) and 3 (b) show the filter characteristics of the equation (18). By using the filter having such a characteristic, in addition to the disturbance observer characteristic having the conventional low frequency velocity fluctuation suppressing effect, a characteristic capable of selectively suppressing the velocity fluctuation at a specific frequency can be added.

As described above, the filter characteristic is set by utilizing the fact that the filter characteristic and the speed fluctuation ratio have the relationship as shown in the equation (16). As a result, the speed fluctuation suppressing effect can be freely designed to some extent according to the characteristics of the control system including the controlled object. In the above-described embodiment, both low frequency irregular speed fluctuations and high frequency regular speed fluctuations that have been difficult to apply conventionally can be effectively suppressed. This is effective for improving the image quality of VTR and FAX and improving the reliability of the information recording / reproducing apparatus using the motor.

Further, if the disturbance torque compensating means is constructed by providing both the disturbance torque compensating means 35 shown in FIGS. 1 and 2 and the filter characteristic shown in FIG. 5, the disturbance observer system without the current control loop can be used. It is possible to remove the influence of the internal induced voltage of the motor and the viscosity, and to suppress the speed fluctuation of a specific high frequency such as torque ripple with a simple configuration.

[0083]

As described above, according to the present invention, the following effects can be obtained. First, even if the current control loop, which is the premise of the conventional disturbance observer method, is omitted, according to the present invention, the disturbance torque estimated value correction means for correcting the influence of the internal induced voltage or / and the viscosity characteristic of the motor to be controlled is provided. Since it is provided, it is possible to perform sufficiently accurate disturbance torque compensation. As a result, the size and weight of the device can be reduced and the cost can be reduced, and the device can be applied to the motor control of the information recording / reproducing apparatus to prevent the deterioration of image quality and sound quality or the reliability of the data streamer.

Further, paying attention to the simple relationship between the filter characteristics for making the disturbance non-reactive and the speed fluctuation ratio, irregular speed fluctuations at low frequencies and regular speed fluctuations at high frequencies which have been difficult to apply in the past. Since the filter characteristics are set so as to reduce both of these, it is possible to effectively suppress the low-frequency speed fluctuation of the unspecified frequency and the relatively high-frequency speed fluctuation with a simple configuration. As a result, it is effective for improving the image quality of VTR and FAX and improving the reliability of the information recording / reproducing apparatus using the motor. Further, there is an advantage that the control characteristics according to each model can be easily designed.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a main part of a motor speed control device according to an embodiment of the present invention.

FIG. 2 is a block diagram of the embodiment shown in FIG.

FIG. 3 is an explanatory diagram for deriving a function of a disturbance torque estimated value correction means of the embodiment in FIG.

FIG. 4 is a diagram showing a comparison of gain characteristics of speed fluctuation with respect to a disturbance torque in order to explain effects of the embodiments of FIGS.

FIG. 5 is a block diagram of a main part of a motor speed control device according to another embodiment of the present invention.

FIG. 6 is a diagram showing a design example of a velocity fluctuation ratio for explaining the principle for setting the filter characteristic, (a) showing a gain characteristic, and (b) showing a phase characteristic.

7A and 7B are diagrams showing the characteristics of the filter of the embodiment of FIG. 5, where FIG. 7A is a gain characteristic and FIG. 7B is a phase characteristic.

[Explanation of symbols]

 11 motor 12 load 13 speed detection means 22 speed control means 23 addition means 24 motor driver 30 disturbance torque compensation means 31 motor torque model 32 load torque inverse model 33 motor torque inverse model 34 low pass filter 35 disturbance torque estimated value correction means 227 filter block

 ─────────────────────────────────────────────────── --- Continuation of the front page (72) Inventor Nobuyoshi Muto 4026 Kujimachi, Hitachi City, Ibaraki Prefecture Hitachi Research Laboratory, Ltd. (72) Toshio Nagata 1410 Inada, Katsuta City, Ibaraki Hitachi Ltd. in the factory

Claims (8)

[Claims] 1. A speed control means for adjusting a voltage command value of the motor so as to match a detected speed value of the motor with a speed command value, and a motor drive means for controlling an input voltage of the motor based on the voltage command value. And inputting the voltage command value and the speed detection value, obtaining an estimated value of the torque disturbance based on a model simulating the motor and the load of the motor, and canceling the estimated torque disturbance value. In a motor speed control device comprising a disturbance torque compensating means for correcting a voltage command value, a disturbance torque estimated value correction for inputting the speed detected value and correcting the torque disturbance estimated value according to the speed detected value A motor speed control device comprising means. 2. The torque disturbance compensating means according to claim 1, wherein the voltage command value is input.
A motor torque model for multiplying the voltage command value by a preset torque constant to obtain an estimated torque generated by the motor, and a preset load inertia moment of the motor by inputting the speed detection value. Based on a correlation function between load input torque and speed, a load torque inverse model for obtaining a load input torque estimated value corresponding to the speed detected value, and a difference between the torque estimated values is input as a disturbance torque estimated value, A motor torque inverse model for obtaining a correction value of the voltage command value of the motor by dividing the estimated disturbance torque value by the torque constant, and a speed correction means for adding the correction value of the voltage command value to the voltage command value. A motor speed control device comprising: 3. The motor speed control device according to claim 2, wherein the torque disturbance compensating unit has a low-pass filter provided on the output side of the motor torque inverse model. 4. The torque disturbance estimated value correction means according to claim 1, further comprising a proportional element for multiplying the speed detection value by a constant value, and outputting the output of the proportional element to the disturbance. A motor speed control device that adds or subtracts to an estimated torque value. 5. The gain according to claim 4, wherein the gain of the proportional element is a value obtained by dividing a product of a torque constant of the motor and an induced voltage constant by a coil resistance value of the motor, or a value obtained by the gain. A motor speed control device characterized by being set to a value obtained by adding a viscosity constant of a motor and a load. 6. A speed control means for adjusting a control amount command value of the motor so that a detected speed value of the motor matches a speed command value, and an input control amount of the motor is controlled based on the control amount command value. A motor drive means, the control amount command value and the speed detection value are input, an estimated value of torque disturbance is obtained based on a model simulating the motor and the load of the motor, and the estimated torque disturbance value is calculated. A motor speed control device comprising: a disturbance torque compensating unit that obtains a correction value of the control amount command value so as to cancel and corrects the control amount command value by a value obtained by filtering the correction value. Is a transfer function of a first- or higher-order high-pass filter, and the gain of at least one of the torque ripple and the power supply noise of the motor is reduced in the frequency or frequency band. The motor speed control device is characterized in that the transfer function obtained by multiplying the transfer function is set to a function obtained by subtracting 1 from the transfer function. 7. A speed control means for adjusting a control amount command value of the motor so that a detected speed value of the motor coincides with a speed command value, and an input control amount of the motor is controlled based on the control amount command value. The motor drive means, the control amount command value is input, the motor torque model for calculating the generated torque estimated value of the motor by multiplying the control amount command value by a preset torque constant, and the speed detection value are input. , A load torque inverse model that obtains a load input torque estimated value corresponding to the speed detection value based on a preset correlation function between the load input torque and the speed including the load moment of inertia of the motor, A motor torque inverse model in which a difference between estimated torque values is input as a disturbance torque estimation value, and the disturbance torque estimation value is divided by the torque constant to obtain a correction value for the control amount of the motor. A motor speed control device comprising: filter means for filtering the correction value of the control amount; and speed correction means for adding the correction value filtered by the filter means to the control amount command value, The filter means has a transfer function obtained by subtracting a product of transfer functions of a high-pass filter of a first order or higher and a notch filter from 1, and the transfer function of the notch filter is at least one of torque ripple and power source noise of the motor. A motor speed control device characterized by being set to a transfer function for reducing a gain of a frequency or a frequency band. 8. A speed control means for adjusting a voltage command value of the motor so as to match a detected speed value of the motor with a speed command value, and a motor driving means for controlling an input voltage of the motor based on the voltage command value. And a motor torque model for inputting the voltage command value and multiplying the voltage command value by a preset torque constant to obtain an estimated torque generated by the motor, and inputting the speed detection value and presetting. A load torque inverse model that obtains a load input torque estimated value corresponding to the speed detection value based on a correlation function between the load input torque including the load inertia moment of the motor and the speed, and a difference between the torque estimated values. Is input as a disturbance torque estimated value, and the disturbance torque estimated value is divided by the torque constant to obtain a correction value of the voltage command value of the motor, and a motor torque inverse model, A motor speed control device comprising: filter means for filtering a correction value of a pressure command value; and speed correction means for adding the correction value filtered by the filter means to the voltage command value. A disturbance torque estimated value correction means for inputting a value and correcting the torque disturbance estimated value in accordance with the detected speed value is provided, and the filter means calculates a product of transfer functions of a high-pass filter of a first order or higher and a notch filter by 1 The transfer function of the notch filter is set to a transfer function that reduces the gain of at least one of the torque ripple and the power supply noise of the motor or the frequency band. And a motor speed control device.