JPH0530778A - Rotation controller - Google Patents

Abstract

PURPOSE:To reduce the torque variation and uneven rotation of an electric commutator motor by a rotation controller. CONSTITUTION:An apparatus is provided with a rotation-angle detection circuit 105 for detecting the rotation angle of a motor 102 and a storage circuit 106 for composing waveforms, which are repeated 1K, 2K, 3K... times in one rotation of the motor when the times of switching of the application of power to a coil per one rotation of the motor number K times, and for storing composite waveforms as torque variation-correcting data. When the output of the storage circuit 106 is given to a gain control circuit 107 simultaneously with the output of FG103 and PG104 attached to the motor 102 and a motor control signal is modulated by the torque-correcting data and given to a motor-driving circuit 110 via LPF109, torque correction is automatically conducted according to the rotational position of the motor and the motor 102 is driven by a constant torque.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotation control device for reducing torque fluctuation of an electronic commutator motor and reducing uneven rotation.

[0002]

2. Description of the Related Art In recent years, an oblique scanning type magnetic recording / reproducing apparatus (hereinafter referred to as VT) for recording / reproducing a video signal by a rotary head.
As a rotary head drive motor, a capstan drive motor, a reel drive motor, etc. used for R), a direct current electronic commutator motor of small size, high efficiency and high reliability has been directly connected and used. In such a VTR,
The video signal is recorded on the magnetic recording medium by the rotary head that rotates at high speed by the rotary head drive motor. Therefore, when rotation unevenness occurs in the rotary head drive motor, the time axis called jitter of the reproduced video signal fluctuates, and the reproduced image displayed on the television receiver is shaken laterally to deteriorate the image quality. Therefore, it is necessary to suppress the torque fluctuation of the rotary head drive motor, which is a cause of uneven rotation, to a low level. On the other hand, there is a VTR in which an audio signal is recorded by a head fixed to a running tape. In this case, if the capstan drive motor that runs the tape has uneven rotation, the reproduced audio signal also undergoes time-axis fluctuation called wow and flutter, which causes deterioration of the audio signal. Therefore, also in the capstan drive motor, it is necessary to suppress the torque fluctuation, which is a factor of uneven rotation, to a low level. Further, in the reel drive motor as well, if the fluctuation of the torque is not suppressed, the tape tension of the tape running system fluctuates, which induces uneven rotation of the capstan drive motor and the rotary head drive motor.
This causes horizontal shake of the reproduced image and wow and flutter of the reproduced audio signal.

[0003]

As described above, in the VTR or the like, in order to ensure the stability of the reproduced signal, it is an important issue to suppress the torque fluctuation of the motor used. Conventionally, in order to suppress the rotation unevenness caused by such torque fluctuations of the motor, measures have been used by increasing the moment of inertia of the rotating body and increasing the gain of the motor control system. However, in a portable VTR, the moment of inertia of the rotary head drive motor and the capstan drive motor is reduced in order to reduce the weight and downsize. Further, in the case of direct connection drive, the rotation speed of the drive motor slows down, so it is impossible to suppress the rotation unevenness only by conventional measures such as increasing the moment of inertia of the motor and increasing the gain of the control system. Had a point.

Next, the cause of the uneven rotation of the motor will be described in detail. First, the torque fluctuation generated by the electronic commutator motor used for the rotary drive system of the VTR will be briefly described. This motor is a 4-coil, 6-pole magnetized electronic commutator motor that is driven by two-phase full-wave. FIG. 11 is an explanatory diagram showing the basic structure of the electronic commutator motor. (A) is a figure which shows the magnetization distribution of the rotor magnet 1, (b) is a figure which shows the coil arrangement of the stator coil board 2. FIG. In the figure, in the rotor magnet 1, S poles and N poles are alternately magnetized every 60 ° in mechanical angle. Further, stator coils L1, L2, L3, and L4 are arranged on the stator coil substrate 2 at a pitch of 90 ° in mechanical angle.
L2, L3, and L4 are mechanical angles of 60 ° (that is, N
Or the width of one permanent magnet of S). And these coils L1, L2, L3, L4
Are arranged with a phase difference of 90 ° in mechanical angle. In addition, the first for detecting the rotational position of the rotor magnet 1 and controlling the timing of energizing the coils L1 to L4
Hall element H1 and second hall element H2 are provided at the midpoints of coils L1 and L2 and the midpoints of coils L4 and L1, respectively.

12 and 13 are circuit diagrams showing an example of a motor drive circuit for driving an electronic commutator motor. 12
In, differential amplifiers AMP1 and AMP2 are differential amplifiers that amplify the outputs of the Hall elements H1 and H2. The inverting gate circuits INV1 to INV4 include differential amplifiers AMP1 and
The output of AMP2 is inverted and converted to a logic level, and the outputs of INV1 to INV4 are given to AND gate circuits AND1 to AND4. The AND gate circuits AND1 to AND4 are the transistors T shown in FIG.
A gate pulse is applied to r5 to Tr8. Figure 1
The circuit 3 is a drive circuit unit for the coils L1 to L4 of the motor, and is a transistor Tr that is switched by receiving pulse signals from the output signals S1 to S4 in FIG.
5～Tr8, transistor Tr1~Tr4 turning on and off the power supply V _cc 2, resistors R1 to R13, capacitor C1
To C2 and coils L1 to L4.

The rotor magnet 1 of the motor is shown in FIG.
When rotating in the arrow direction X of (a), outputs Ha1 and Ha2 at both ends of the Hall element H1 and outputs Hb1 and Hb2 at both ends of the Hall element H2 of FIG.
Outputs A and B of V1 and INV3, AND gate circuit AN
The waveforms of the outputs S1, S2, S3 and S4 of D1 to AND4 are as shown in FIG.

The output waveforms of the Hall elements H1 and H2 are shown in FIG.
Output Ha1, Ha2, Hb1, and Hb2, the rotor magnet 1 has a repetitive waveform having one cycle in the section of one pair of the S pole and the N pole.
One cycle becomes 20 °. Hereinafter, the rotation angle 120 ° (mechanical angle 120 °) of the rotor magnet 1 is defined as an electrical angle 360 °. The Hall elements H1 and H2 have a mechanical angle of 90.
270 in electrical angle because they are installed separated by °
°, ie, mechanical angle 90 °, output waveforms Ha1 with different phases,
Hb1 is obtained. The outputs Ha2 and Hb2 are signals having opposite phases to the outputs Ha1 and Hb1, respectively.

The outputs Ha1 and Ha2 are differential amplifiers AMP1.
And the inverting gate circuit INV1 shapes the waveform into the rectangular wave A, and Hb1 and Hb2 are shaped into the rectangular wave B by the differential amplifier AMP2 and the inverting gate circuit INV3. The rectangular wave A and the rectangular wave B have a phase difference of 90 ° in electrical angle as shown in FIG. 14, and the inverting gate circuit INV2
Inverted waveform A ′ of signal A, inverted gate circuit INV
4 gives the inverted waveform B ′ of the signal B. Then, the AND gate circuits AND1 to AND4 cause the signals S1 to S1.
When S4 is obtained, as shown in FIG.
It becomes a high level in the section of °, and becomes a rectangular wave with a cycle of electrical angle of 360 °. This signal becomes a signal whose phase is delayed by 90 ° in the order of S1 → S2 → S4 → S3, and the timing of energization of the coils L1 to L4 is controlled by these rectangular wave signals.

The section in which the output S4 is at high level is T1,
T is a section in which the outputs S3, S1, S2 are at high level, respectively.
2, T3 and T4, in the section T1, the transistor T
The r1 and Tr6 are turned on, and a current flows from the coil L3 to the coil L1. In the section T2, the transistors Tr3 and Tr
8 is turned on, and a current flows from the coil L4 to the coil L2. Similarly, in the section T3, the transistors Tr2 and Tr5 are turned on and current flows from the coil L1 to the coil L3, and in the section T4, the transistors Tr4 and Tr7 are turned on and current flows from the coil L2 to the coil L4.

Next, the principle of torque generation of the electronic commutator motor will be described. In FIG. 15, N of the rotor magnet 1
A sinusoidal magnetic field is formed by the permanent magnets alternately magnetized in S. The relative positional relationship between the magnetic flux densities B1 to B6 and the coils L1 to L4 when the rotor magnet 1 is rotating is as shown in this figure.

In the section T1 shown in FIG. 15, the product of the current flowing in the coil L1 and the magnetic flux densities B2 and B3 in each section indicated by the arrow, and the current flowing in the coil L3 and each magnetic flux density B5,
Torque is generated by the product of B6. Similarly, in section T2,
The product of the current flowing in the coil L2 and the magnetic flux densities B1 and B2, and the current flowing in the coil L4 and the magnetic flux densities B4 and B
The product of 5 and the torque is generated. Similarly, in the section T3, the product of the current flowing through the coil L1 and each magnetic flux density B3, B4,
Also, torque is generated by the product of the current flowing through the coil L3 and the magnetic flux densities B6 and B1. Further, in the section T4, the coil L2
Torque is generated by the product of the current flowing in the coil and the magnetic flux densities B2 and B3, and the product of the current flowing in the coil L4 and the magnetic flux densities B5 and B6.

Since the curves of the magnetic flux densities B1 to B6 have the same waveform, the sections T1 flowing through the coils L1 to L4 are the same.
If the switched current value from T4 to T4 is constant, the torque fluctuation per rotation of the rotor magnet 1 is as shown in FIG.
As shown in FIG. 6, one cycle has a repetitive waveform having a rotation angle (mechanical angle) of 30 °. In this way the rotor magnet 1
The rotational torque generated by the excitation of each coil L1 to L4 is in a state including an AC component having peaks and valleys in each section T1 to T4. For this reason, in the electronic commutator motor, a rotation torque variation of 12 cycles occurs for each rotation of the rotor magnet 1, which causes uneven rotation.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide a rotation control device which suppresses rotation unevenness due to torque fluctuation of a motor.

[0014]

According to the invention of claim 1 of the present application, a rotor magnetized to a plurality of poles and rotatably held,
A rotation control device for a motor having a plurality of sets of exciting coils formed at a position facing the rotor and a stator including a rotation sensor for detecting a rotation position of the rotor, wherein a rotation position of the rotor is detected and a rotation angle is detected. Rotation angle detecting means for outputting information, and torque fluctuation correction for changing the exciting current of the exciting coil so as to have an approximately reciprocal relation with the magnetic flux density of the rotor in order to reduce the rotational torque fluctuation caused by the change of the magnetic flux density of the rotor. Storage means for storing data and sequentially reading the rotation angle information from the rotation angle detection means, and gain control means for controlling the gain of the rotation control signal for controlling the rotation of the motor by the torque fluctuation correction data output from the storage means. And a low-pass filter that passes only the low-frequency components of the signal output from the gain control means. A.

According to a second aspect of the present invention, a rotor rotatably held by magnetizing a plurality of poles, a plurality of sets of exciting coils formed at positions facing the rotor, and a rotational position of the rotor are provided. A rotation control device for a motor having a stator including a rotation sensor for detecting, a rotation angle detecting means for detecting a rotation position of a rotor and outputting rotation angle information, and a rotation torque fluctuation caused by a change in magnetic flux density of the rotor. In order to reduce the torque, torque fluctuation correction data for changing the exciting current of the exciting coil to have an approximately reciprocal relation with the magnetic flux density of the rotor is stored, and a storage unit that sequentially reads the rotation angle information from the rotation angle detection unit, Gain control means for controlling the gain of the rotation control signal for controlling the rotation of the motor based on the torque fluctuation correction data output from the storage means. The torque fluctuation correction data is created by the torque fluctuation correction data creating device, and the torque fluctuation correction data creating device is configured such that when the number of energization switching of the exciting coil per one rotation of the motor is K times (K is a natural number). In addition, torque fluctuation waveform measuring means for measuring the torque fluctuation waveform for one rotation of the motor, and M times per rotation of the motor included in the torque fluctuation waveform (M is K, 2K, 3K, ...
(Integer of nK) specific frequency component extracting means for extracting repeated frequency components, waveform synthesizing means for adding repeating torque fluctuation component waveforms of respective frequencies extracted by the specific frequency component extracting means, and waveform synthesizing means. And a reciprocal calculation means for calculating the reciprocal of the signal.

According to the invention of claim 3 of the present application, a rotor rotatably held by being magnetized to a plurality of poles, a plurality of sets of exciting coils formed at positions facing the rotor, and a rotational position of the rotor are provided. A rotation control device for a motor having a stator including a rotation sensor for detecting, a rotation angle detecting means for detecting a rotation position of a rotor and outputting rotation angle information, and a rotation torque fluctuation caused by a change in magnetic flux density of the rotor. In order to reduce the torque, torque fluctuation correction data for changing the exciting current of the exciting coil to have an approximately reciprocal relation with the magnetic flux density of the rotor is stored, and a storage unit that sequentially reads the rotation angle information from the rotation angle detection unit, Gain control means for controlling the gain of the rotation control signal for controlling the rotation of the motor based on the torque fluctuation correction data output from the storage means, and a signal output from the gain control means. The is characterized in that it comprises a variable amplifier for amplifying an arbitrary amplification factor.

According to a fourth aspect of the present invention, a rotor rotatably held by being magnetized to a plurality of poles, a plurality of sets of exciting coils formed at positions facing the rotor, and a rotational position of the rotor are provided. A rotation control device for a motor having a stator including a rotation sensor for detecting, a rotation angle detecting means for detecting a rotation position of a rotor and outputting rotation angle information, and a rotation torque fluctuation caused by a change in magnetic flux density of the rotor. Repeated M times included (M is K, 2K, 3K, ...
torque correction data is stored for each frequency component (integer of nK), and a plurality of storage means for sequentially reading out the rotation angle information from the rotation angle detection means and a plurality of storages of gains of rotation control signals for controlling rotation of the motor. A plurality of gain control means for controlling by the torque fluctuation correction data output from the means,
A plurality of variable amplification means for amplifying the signal output from each gain control means with an arbitrary amplification factor, respectively.

Further, according to the invention of claim 5 of the present application, a rotor rotatably held by being magnetized to a plurality of poles, a plurality of sets of exciting coils formed at positions facing the rotor, and a rotational position of the rotor are provided. A rotation control device for a motor having a stator including a rotation sensor for detecting, a rotation angle detecting means for detecting a rotation position of a rotor and outputting rotation angle information, and a rotation torque fluctuation caused by a change in magnetic flux density of the rotor. Repeated M times included (M is K, 2K, 3K, ...
a plurality of storage means for storing the torque fluctuation correction data for each frequency component (integer of nK) and sequentially reading it according to the rotation angle information from the rotation angle detection means, and the gain of the rotation control signal for controlling the rotation of the motor. A plurality of gain control means for controlling by the torque fluctuation correction data outputted from the means, and a plurality of timing correction means for shifting the timing of the output signal of the rotational position detecting means by a predetermined amount to each storage means. It is characterized by.

[0019]

The present invention having the features as described above, claims 1, 2,
According to the third aspect of the invention, the torque fluctuation waveform during one rotation when the torque of the motor is not corrected is corrected by the torque fluctuation correction data generation device or the like to obtain a reciprocal function that becomes constant when multiplied by the torque fluctuation waveform. It is created in advance as correction data and stored in the storage means. Then, the torque fluctuation correction data is read from the storage means based on the rotation angle information from the rotation angle detection means, the motor control signal is modulated through the gain control means, and the result is supplied to the motor drive circuit. By doing so, a constant rotational torque can be obtained regardless of the rotational position of the rotor, and uneven rotation can be reduced.

According to the fourth and fifth aspects of the present invention, the torque fluctuation waveform during one rotation when the torque of the motor is not corrected is measured in advance by the torque fluctuation correction data creating device or the like. This torque fluctuation waveform is M per revolution of the motor.
Frequency components that are repeated twice (M is an integer of K, 2K, 3K, ..., nK) are extracted, and torque fluctuation correction data for each frequency component is stored in a plurality of storage means, and torque fluctuations during one rotation of the motor are stored. The motor control signal is modulated through a plurality of gain control circuits and provided to the motor drive circuit so as to correspond to the positional deviation of each peak of the waveform and the variation of each motor.
By doing so, a constant rotational torque can be obtained corresponding to the rotational position of the rotor and its variation, and individual motors, and uneven rotation can be reduced.

[0021]

(First Embodiment) A first embodiment of the present invention will be described below with reference to FIGS. 1, 2 and 3. FIG. 1 is a block diagram showing a schematic configuration of a rotary drive device according to a first embodiment of the present invention. In FIG. 1, an electronic commutator motor unit 101 includes an electronic commutator motor (hereinafter simply referred to as a motor) 102, a rotation speed detection signal generator (referred to as FG) 103, and a rotation position detection signal generator (referred to as PG) 104. It is configured to include. The motor 102 is shown in FIG.
It has a rotor magnet 1 of 6-pole magnetization having the same structure as that shown in FIG. 1 (a), and a stator coil substrate 2 shown in FIG. 11 (b). The rotation speed detection signal generator 103 outputs a pulse signal P1 of, for example, 100 pulses per one rotation of the rotor magnet 1, which is proportional to one rotation of the motor 102. Rotational position detection signal generator 104
Outputs a pulse signal P2 of one pulse per one rotation of the rotor magnet 1 at a specific rotation position.

The pulse signals P1 and P2 are given to the rotation angle detection circuit 105. The rotation angle detection circuit 105 outputs rotation angle information corresponding to the rotation angle of the motor 102 from a specific rotation position, and detects the rotation angle together with the rotation speed detection signal generator 103 and the rotation position detection signal generator 104. Constitutes a means. Rotation angle detection circuit 10
The pulse signal P2 is composed of, for example, a counter circuit.
Is used as a reset signal to count the pulse signal P1. The rotation angle information output from the rotation angle detection circuit 105 becomes zero when the pulse signal P2 is input, the count value is incremented by 1 each time the pulse signal P1 is input, and the rotation angle information of the motor 102 is output. Is something
The signal is given to the memory circuit 106. Memory circuit 10
Reference numeral 6 denotes a storage means for storing torque fluctuation correction data for reducing the torque fluctuation of the motor 102, as will be described later.
For example, it is composed of a read-only memory (ROM). The output of the memory circuit 106 is given to the gain control circuit 107.

The gain control circuit 107 is a circuit for amplifying or attenuating the output of the motor control signal generating circuit 108 for controlling the rotation of the motor 102, and the storage circuit 106.
It is a gain control means whose gain is controlled by the torque fluctuation correction data output from the output of the low-pass filter (LPF) 109. The LPF 109 is a low-pass filter and passes a component of a motor control signal output from the gain control circuit 107, which component has a frequency equal to or lower than a specific frequency. The output of the LPF 109 is the motor drive circuit 11.
Given to 0. The motor drive circuit 110 switches a drive current corresponding to the voltage of the motor control signal to energize the coils L1 to L4 of the motor 102.

FIG. 2 is a waveform diagram showing a torque fluctuation waveform of the motor 102 and a torque fluctuation correction waveform. Figure 2 (a)
As described above, indicates the output torque of the motor when the motor 102 is driven with a constant switching current. In addition to the DC average torque, AC torque that fluctuates 12 times per revolution is generated. Only the AC component is shown. As a method of measuring the torque fluctuation waveform, a constant current is passed through the motor, and while changing the relative position between the rotor magnet 1 and the stator coil substrate 2 shown in FIG. There is a method of measuring the voltage output from the device. Further, there is a method of obtaining the torque fluctuation based on the counter electromotive force waveform generated in the coils L1 to L4 during rotation of the motor 102 in consideration of the coil energization switching timing and the coil energization direction. Next, as shown in FIG. 2B, the torque fluctuation correction signal G1 to be stored in the storage circuit 106 is obtained by calculating the reciprocal of the torque fluctuation waveform of FIG. 2A obtained by the above-described method. . This is stored in the memory circuit 106.

Now, the motor control signal generation circuit 108 outputs the specified rotation speed and rotation torque, and the motor 10
In the state where 2 is rotating, the pulse signal P1 from the rotational speed detection signal generator 103 and the pulse signal P2 from the rotational position detection signal generator 104 are respectively in the rotation angle detection circuit 1.
Given to 05. The rotation angle detection circuit 105 returns the address of the storage circuit 106 to the beginning by the pulse signal P2, and outputs the torque fluctuation correction data stored in the storage circuit 106 by each pulse of the pulse signal P1 according to the rotation angle of the motor 102. The gain control circuit 1 outputs a control signal from the motor control signal generation circuit 108 to instruct the specified rotation speed and average torque.
07, these control signals are applied to the memory circuit 10.
It is modulated by the output signal of 6. The control signal of the motor modulated by the torque fluctuation correction signal as shown in FIG. 2B is given to the LPF 109. The LPF 109 is shown in FIG.
As shown in FIG.
As shown by the waveform portion Z in (c), a waveform in which a steep peak is removed is output. Next, when the torque fluctuation correction data shown in FIG. 2C is given to the motor drive circuit 110, the AC component of the output torque becomes flat, and the motor 102 rotates at a constant torque.

FIGS. 3A, 3B and 3C are explanatory views of the torque correction of the motor. (A) is a torque fluctuation waveform of the motor before correction. (B) is a waveform obtained by converting the torque fluctuation waveform shown in (a) into its inverse by a calculation process. Generally, an assembly error occurs when assembling a motor,
Due to a mounting error of the rotational position detection signal generator 104 with respect to the rotor magnet 1, the motor 10 of FIG.
As shown in (b), the phase of the torque fluctuation correction signal output from the storage circuit 106 may deviate within the range of the time Tx with respect to the rotational torque at the time of non-correction. Here, if the output torque fluctuation of (a) is corrected by the torque fluctuation correction signal shown in (b), the actual torque fluctuation waveform when the motor 102 is driven becomes as shown in (c). That is,
When the torque fluctuation in the section of time Tx becomes abrupt and the angular deviation of the rotational position detection signal generator 103 becomes large, the rotational unevenness may increase as compared to before correction.

On the other hand, the waveform of FIG.
When the motor is driven by the torque fluctuation correction signal of (d) obtained through 109, the actual torque fluctuation waveform becomes flat as shown in (e), and the correction effect of the low frequency component of the torque fluctuation is produced. It should be noted that although the high frequency components are not sufficiently corrected, the abrupt torque fluctuation during the period of time Tx is reduced, and the influence of the timing deviation of the torque fluctuation correction signal on the torque fluctuation waveform shown in (a) should be mitigated. The effect of being able to do occurs. Further, there is a practical effect that stable torque fluctuation correction can be obtained even with respect to a motor assembly error.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to the drawings. FIG. 4 is a block diagram showing a schematic configuration of a torque fluctuation correction data creation device 400 connected to the rotation control device in the second embodiment of the present invention. In this figure, torque fluctuation waveform measuring means 4
Reference numeral 01 denotes a torque output value that changes corresponding to the rotational position of the motor 102 to create a torque fluctuation waveform during one rotation of the motor 102, the output of which is given to the specific frequency component extraction means 402. Specific frequency component extraction means 40
2 is for performing Fourier transform on the output signal of the torque fluctuation waveform measuring means 401 to separate it into specific frequency components.
FIG. 5 is a waveform chart showing a torque fluctuation waveform of the motor and each waveform when the waveform is separated into specific frequency components.
FIG. 5 (a) shows the same torque fluctuation waveform as in FIG. 2 (a). When the 6-pole magnetized / 4-coil motor 102 is driven in two-phase full-wave mode as described above, coil energization switching is performed. Similar to the number of times, the repetitive waveform is 12 times for one rotation of the motor. When this waveform is decomposed into components having a frequency that is an integral multiple of (a) by, for example, Fourier transform, the waveforms shown in (b), (c), and (d) are obtained. That is, (b) is one rotation 1 included in the torque fluctuation waveform of (a).
The waveform of the repetitive component (W12) is twice, similarly, (c) is the waveform of the repetitive component (W24) of 24 times per rotation, and (d) is the repetitive component (W of 36 times per rotation).
36) is the waveform.

Next, the output of the specific frequency component extracting means 402 is given to the waveform synthesizing means 403. Waveform synthesis means 40
3 are components W12, W24, of the signals extracted by the specific frequency component extracting means 402 shown in FIGS.
The waveform of W36 is added. As shown in FIG. 5E, a waveform from which the high frequency component of the torque fluctuation waveform is removed can be obtained by this combining process. The output of the waveform synthesizer 403 is given to the reciprocal calculator 404. The reciprocal calculation means 404 outputs the reciprocal waveform of the output signal of the waveform synthesizing means 403 to obtain torque fluctuation correction data for the torque fluctuation waveform of (a).

FIG. 6 is a block diagram showing the overall construction of the rotation control device according to the second embodiment of the present invention. The same parts as those in FIG. 1 of the first embodiment are designated by the same reference numerals and detailed description thereof will be omitted. 1 is different from FIG. 1 in that a storage circuit 405 and a torque fluctuation correction data creation device 400 for giving torque fluctuation correction data to the storage circuit 405 are provided as a storage means instead of the storage circuit 106, and the LPF 109 is omitted. Is. The torque fluctuation correction data created by the torque fluctuation correction data creation device 400 is shown in FIG.
By storing it in 05, the LPF 10 as shown in FIG.
The same effect as that of the first embodiment of the present invention can be obtained without using 9. Further, in the first embodiment, when the motor rotation speed changes depending on the tape speed like the VTR capstan motor, it is necessary to change the frequency characteristic of the LPF 109 according to the rotation speed, but in the present embodiment, The advantage is that a stable torque fluctuation correction effect can be obtained regardless of the number of motor revolutions. The torque fluctuation correction data creation device 400 does not need to be always connected to the storage circuit 405, and may be connected only when storing the torque fluctuation correction data in the storage circuit 405.

(Third Embodiment) Next, a third embodiment of the present invention will be described with reference to the drawings. FIG. 7 is a block diagram showing a schematic configuration of the third embodiment of the present invention. In this case as well, the same parts as those in FIG. In FIG. 7, a storage circuit 501 is a storage unit that stores the torque fluctuation correction data obtained by the torque fluctuation correction data creation device 400 of the second embodiment. The gain control circuit 107 is controlled by the torque fluctuation correction data output from the storage circuit 501 so as to increase or decrease the gain, and outputs the gain. The variable amplification circuit 502 is a variable amplification means for further amplifying its output with an arbitrary amplification factor. For example, when the distance between the rotor magnet 1 and the stator coil substrate 2 changes due to the assembly error of the motor 102 or the magnetizing strength of the rotor magnet 1 changes, the same current is applied to the motor within the period of the rotation cycle. Also, the amplitude TA of the torque fluctuation changes as shown in FIG. Therefore, it is necessary to change the amplitude TB of the correction signal shown in FIG. 5E according to the change in the amplitude TA of the torque fluctuation, and the variable amplification circuit 502 changes the AC component of the correction signal to obtain the optimum correction effect. Make adjustments to obtain.

According to the present embodiment, the variable amplifier circuit 5 responds to the change in the amplitude TA of the torque fluctuation of each motor 102.
02, it is possible to adjust the amplification factor of the AC component of the correction amount to an optimum value, and reliable correction can be obtained regardless of the assembly error of the motor 102 and the variation in the magnetization intensity of the rotor magnet 1. The effect occurs.

(Fourth Embodiment) Next, a fourth embodiment of the present invention will be described with reference to the drawings. FIG. 8 is a block diagram showing a schematic configuration of the fourth embodiment of the present invention. The same parts as those in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted. In FIG. 8, the output of the rotation angle detection circuit 105 is simultaneously given to the three storage circuits 601, 602, 603. The storage circuit 601 is a storage unit that stores the fundamental frequency component W12 of the torque fluctuation correction data obtained in the second embodiment of the present invention. Similarly, the memory circuit 602 is a memory means for storing the component W24 having twice the fundamental frequency, and the memory circuit 603 is also a memory means for storing the component W36 component having three times the fundamental frequency. Each memory circuit 601, 602, 603
Are read out in accordance with the rotation angle detection signal and applied to the gain control circuits 604, 605, 606, respectively.

The gain control circuit 604 is a circuit for amplifying or attenuating the signal from the motor control signal generating circuit 108, and its gain is controlled by the torque fluctuation correction data output from the storage circuit 601. Similarly, the gain control circuit 605 and the gain control circuit 606, the gain of which is controlled by the torque fluctuation correction signal output from the storage unit 602 and the storage circuit 603, respectively, constitute gain control unit. is doing. The outputs of the gain control circuits 604, 605 and 605 are variable amplifier circuits 6 respectively.
07,608,609. Variable amplifier circuit 60
7, 608 and 608 are gain control circuits 604 and 60, respectively.
It is a variable amplification means for amplifying the AC signal contained in each output signal of 5,606 with an arbitrary amplification factor, and each output thereof is given to the addition circuit 610. The adder circuit 610 is for adding the output signals of the variable amplifier circuits 607, 608, 609, and the output thereof is given to the motor drive circuit 110.

For example, when the distance between the rotor magnet 1 and the coils L1 to L4 changes or the magnetizing strength of the rotor magnet 1 changes due to a motor assembly error, even if the same current is applied to each motor. The amplitude TA of the torque fluctuation changes as shown in FIG. Further, when the torque fluctuation is frequency-analyzed, the amplitudes TC, TD of the components W12, W24, W36 shown in FIGS. 5 (b), (c), and (d), respectively,
TE is obtained and its value is different for each motor. Therefore, the amplitude T of each torque of the components W12, W24, W36
The variation of C, TD, and TE for each motor is adjusted by the variable amplification circuits 607, 608, and 609 so that the AC component of the correction signal is changed to obtain the optimum correction effect. The method of adjusting the gains of the variable amplifier circuits 607, 608, 609 is such that the motor 102 is rotated under speed control, and the rotation speed detection signal output from the rotation speed detection signal generator 103 at that time is provided separately. The gain may be adjusted so that the rotation speed unevenness signal output from the liminator is frequency-analyzed and the torque fluctuation value of the frequency component corresponding to each component W12, W24, W36 is minimized. .

According to the present embodiment, the variable amplification circuits 607, 608, 609 respond to variations in the amplitudes TC, TD, TE of the frequency components of the torque fluctuation to optimize the amplification factor of the AC component of the correction amount. The value can be adjusted. By doing so, a stable correction effect can be obtained regardless of the assembly error of the motor 102 and the variation in the magnetization intensity of the rotor magnet 1.

(Fifth Embodiment) Next, a fifth embodiment of the present invention will be described with reference to the drawings. FIG. 9 is a block diagram showing a schematic configuration of the fifth embodiment of the present invention. The same parts as those in FIG. 8 are designated by the same reference numerals and the description thereof will be omitted. In FIG. 9, the output of the rotation angle detection circuit 105 is given to each timing correction circuit 701, 702, 703. The timing correction circuits 701, 702, 703 are timing correction means for adding or subtracting a predetermined timing correction value to the rotation angle detection information detected by the rotation angle detection circuit 105, and outputs thereof are storage circuits 704, 705, 706.
Given to. The memory circuits 704, 705, 706 finely determine the read timing of the torque fluctuation correction data of the respective components of the signal components W12, W24, W36 stored therein according to the outputs of the timing correction circuits 701, 702, 703. The gain control circuits 707, 708, and 709 are provided with their outputs.

Generally, an assembly error occurs in the motor, and the error is a relative position error between the Hall elements H1 and H2 for detecting the rotational position of the rotor magnet 1 and the coils L1 to L4.
There are mounting errors of the rotational position detecting device 104, uneven magnetization of the rotor magnet 1, etc. As a result, the torque fluctuation waveform has a more complicated shape. FIG. 10 is a waveform diagram showing the torque fluctuation waveform in this case and each frequency component thereof. Within the time of one rotation cycle, as shown in FIG.
The waveform is distorted compared to the waveform of (a). Figure 10 (a)
The angle value shown in the upper row is the rotation angle of the motor 102 detected by the rotation angle detection circuit 105. The waveform shown in FIG. 10 (b) is the reciprocal of the fundamental frequency component W12 included in the torque fluctuation waveform of FIG. 10 (a), and is the angle with respect to the rotation angle information output from the rotation angle detection circuit 105. θ
_{If the} correction data is read from the storage circuit 704 with the timing shifted by _{1, the} torque fluctuation component W1 can be obtained without angular deviation.
2 can be corrected. Similarly, the waveform of FIG.
(A) is a reciprocal of the frequency component W24 that is twice the signal included in the torque fluctuation waveform, and the timing is shifted by an angle θ _{2 with} respect to the rotation angle signal output from the rotation angle detection circuit 105. If the correction data is read from the storage circuit 705, the component W24 can be corrected without an angular deviation. The waveform shown in FIG. 10D is also the reciprocal of the triple frequency component W36, and the storage circuit with the timing θ ₃ shifted with respect to the rotation angle signal output from the rotation angle detection circuit 105. If you read the correction data from 706,
The component W36 can be corrected without any angular deviation. The correction data obtained in this manner are used as gain control circuits 707, 708,
After passing through 709, it is given to the addition circuit 610 and added, and the addition output is given to the motor drive circuit 610. When the motor 102 is driven with such a torque fluctuation correction waveform, even if an angular deviation of each torque fluctuation component occurs due to an assembly error of the motor or the like, it is stabilized by finely adjusting the correction data generation timing for each frequency component. The effect is that correction can be obtained.

[0039]

As described in detail above, according to the inventions of claims 1, 2 and 3, the torque fluctuation during one rotation of the motor is measured in advance by a torque fluctuation correction data generating device or the like, A function having an inverse relationship of the torque fluctuation waveform is stored in the storage means. Therefore, the motor control signal for correcting the torque fluctuation of the motor can be automatically generated through the gain control means, and when this is given to the motor drive circuit, a constant torque output can be obtained regardless of the rotation angle of the rotor. You can Therefore, it is possible to easily reduce the rotation unevenness of the electronic commutator motor or the like having low inertia, and it is possible to realize the rotation control device capable of reducing the size and weight of the magnetic recording / reproducing device.

Further, according to the inventions of claims 4 and 5 of the present application,
In addition to the effects of claims 1, 2 and 3, variations in the characteristics of the motors that occur during the production of the electronic commutator motor, that is, variations in the magnetization of the rotor and the excitation characteristics of the exciting coil of the stator, and a rotational position detection device. Even if there is variation in the mounting position of (PG) with respect to the rotor, a plurality of storage means,
By providing the gain control means, the timing correction means and the like to individually correct the torque, it is possible to realize an excellent rotation control device in which the output torque is automatically constant.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a rotation control device in a first embodiment of the present invention.

2A and 2B are explanatory diagrams for performing torque fluctuation correction according to the first embodiment of the present invention. FIG. 2A is a torque fluctuation waveform, FIG. 2B is a conventional torque fluctuation correction waveform, and FIG. It is a torque fluctuation correction waveform.

3A and 3B are waveform charts showing a procedure for synthesizing torque fluctuation correction waveforms in the first embodiment of the present invention, where FIG. 3A is a torque fluctuation waveform chart, and FIG. 3B is a conventional torque fluctuation correction waveform.
(C) is the torque fluctuation waveform corrected by (a) and (b), (d) is the torque fluctuation correction waveform of the first embodiment, (e)
Is a torque fluctuation waveform corrected by (a) and (d).

FIG. 4 is a block diagram showing a configuration of a torque fluctuation correction data creation device according to a second embodiment of the present invention.

FIG. 5 is a waveform diagram showing a procedure for synthesizing torque fluctuation correction waveforms in the second embodiment of the present invention, (a) is a torque fluctuation waveform, and (b), (c), and (d) are torque fluctuation corrections. It is a waveform diagram which shows the waveform component which repeats 12, 24, 36 times in 1 rotation of a motor among waveforms. (E) shows a torque fluctuation correction waveform obtained by combining the waveform components.

FIG. 6 is a block diagram showing a schematic configuration of a rotation control device in a second embodiment of the present invention.

FIG. 7 is a block diagram showing a schematic configuration of a rotation control device in a third embodiment of the present invention.

FIG. 8 is a block diagram showing a schematic configuration of a rotation control device in a fourth embodiment of the present invention.

FIG. 9 is a block diagram showing a schematic configuration of a rotation control device in a fifth embodiment of the present invention.

FIG. 10 is a waveform chart showing a procedure for synthesizing torque fluctuation correction data in the fifth embodiment of the present invention.

11A and 11B are explanatory views showing a structure of an electronic commutator motor, where FIG. 11A is a plan view of a rotor magnet, and FIG. 11B is a plan view of a stator coil substrate.

FIG. 12 is a circuit diagram of a front stage portion of a motor drive circuit.

FIG. 13 is a circuit diagram of a switching unit of a motor drive circuit.

FIG. 14 is a waveform diagram showing signal waveforms for explaining the operation of the motor drive circuit shown in FIGS. 12 and 13.

FIG. 15 is a schematic diagram showing a positional relationship between a coil and a rotor magnet when switching energization to each coil.

FIG. 16 is a waveform diagram showing a torque fluctuation waveform.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 rotor magnet 2 stator coil substrate L1-L4 coil 101 electronic commutator motor unit 102 electronic commutator motor 103 rotational speed detection signal generator 104 rotational position detection signal generator 105 rotational angle detection devices 106, 405, 501, 601 to 603 , 704-7
05 storage circuit 107, 604 to 606, 707 to 709 gain control circuit 108 motor control signal generation circuit 109 LPF 110 motor drive circuit 400 torque fluctuation correction data creation device 401 torque fluctuation waveform measurement means 402 specific frequency component extraction means 403 waveform synthesis means 404 Reciprocal calculation means 610 Addition circuits 701 to 703 Timing correction circuit

[Procedure amendment]

[Submission date] August 23, 1991

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Name of item to be corrected] Fig. 12

[Correction method] Added

[Correction content]

[Fig. 12]

Claims (5)

[Claims] 1. A stator including a rotor that is magnetized into a plurality of poles and is rotatably held, a plurality of sets of exciting coils formed at positions facing the rotor, and a rotation sensor that detects a rotational position of the rotor. A rotation control device for a motor, comprising: a rotation angle detecting means for detecting a rotation position of the rotor and outputting rotation angle information; and a rotation angle detecting means for reducing a rotation torque fluctuation caused by a change in a magnetic flux density of the rotor. Storage means for storing torque fluctuation correction data for changing the exciting current of the coil so as to have an approximately inverse relationship with the magnetic flux density of the rotor, and for sequentially reading out the rotation fluctuation information from the rotation angle detection means; Gain control means for controlling the gain of the rotation control signal for controlling rotation by the torque fluctuation correction data output from the storage means; Rotation control apparatus for a motor, characterized by comprising, a low-pass filter which passes only low frequency components of the signal. 2. A rotor including a rotor magnetized to have a plurality of poles and rotatably held, a plurality of sets of exciting coils formed at positions facing the rotor, and a rotation sensor for detecting a rotational position of the rotor. A rotation control device for a motor, comprising: a rotation angle detecting means for detecting a rotation position of the rotor and outputting rotation angle information; and a rotation angle detecting means for reducing a rotation torque fluctuation caused by a change in a magnetic flux density of the rotor. Storage means for storing torque fluctuation correction data for changing the exciting current of the coil so as to have an approximately inverse relationship with the magnetic flux density of the rotor, and for sequentially reading out the rotation fluctuation information from the rotation angle detection means; Gain control means for controlling the gain of a rotation control signal for performing rotation control based on the torque fluctuation correction data output from the storage means. The given torque fluctuation correction data is created by a torque fluctuation correction data creation device, and in the torque fluctuation correction data creation device, the number of energization switching of the excitation coil per one rotation of the motor is K times (K. Is a natural number), torque fluctuation waveform measuring means for measuring the torque fluctuation waveform for one rotation of the motor, and M times per rotation of the motor included in the torque fluctuation waveform (M is K, 2K, 3K). , Integer nK) Specific frequency component extracting means for extracting repeated frequency components, waveform synthesizing means for adding repeating torque fluctuation component waveforms of respective frequencies extracted by the specific frequency component extracting means, and the waveform And a reciprocal calculation means for calculating the reciprocal of the signal obtained by the synthesizing means. . 3. A rotor including a rotor magnetized to a plurality of poles and rotatably held, a plurality of sets of exciting coils formed at positions facing the rotor, and a rotation sensor for detecting a rotational position of the rotor. A rotation control device for a motor, comprising: a rotation angle detecting means for detecting a rotation position of the rotor and outputting rotation angle information; and a rotation angle detecting means for reducing a rotation torque fluctuation caused by a change in a magnetic flux density of the rotor. Storage means for storing torque fluctuation correction data for changing the exciting current of the coil so as to have an approximately inverse relationship with the magnetic flux density of the rotor, and for sequentially reading out the rotation fluctuation information from the rotation angle detection means; Gain control means for controlling the gain of the rotation control signal for controlling rotation by the torque fluctuation correction data output from the storage means; Rotation control apparatus characterized by comprising a variable amplifying means, the amplifying the signal in any amplification factor. 4. A rotor, which is magnetized to have a plurality of poles and is rotatably held, a plurality of sets of exciting coils formed at positions facing the rotor, and a stator including a rotation sensor for detecting a rotational position of the rotor. A rotation control device for a motor having: a rotation angle detecting means for detecting a rotation position of the rotor and outputting rotation angle information; and M times included in a rotation torque fluctuation caused by a change in magnetic flux density of the rotor. (M is K, 2K, 3
Torque correction data is stored for each frequency component (K, ..., nK), and a plurality of storage means for sequentially reading the rotation angle information from the rotation angle detection means, and a rotation control for performing rotation control of the motor. A plurality of gain control means for controlling the gain of the signal based on the torque fluctuation correction data output from the plurality of storage means, and a plurality of variable amplifiers for amplifying the signals output from each of the gain control means with arbitrary amplification factors. And a rotation control device. 5. A rotor including a rotor which is magnetized into a plurality of poles and is rotatably held, a plurality of sets of exciting coils formed at positions facing the rotor, and a rotation sensor which detects a rotational position of the rotor. A rotation control device for a motor having: a rotation angle detecting means for detecting a rotation position of the rotor and outputting rotation angle information; and M times included in a rotation torque fluctuation caused by a change in magnetic flux density of the rotor. (M is K, 2K, 3
K, ... nK) a plurality of storage means for storing torque fluctuation correction data for each frequency component and sequentially reading out the rotation angle information from the rotation angle detection means, and rotation for performing rotation control of the motor. A plurality of gain control means for controlling the gain of the control signal based on the torque fluctuation correction data output from each of the storage means, and a plurality of gain control means for shifting the timing of the output signal of the rotational position detection means to each of the storage means. And a timing correction means for the rotation control device.