JPH07298679A - Rotation controller of motor - Google Patents

Abstract

PURPOSE:To prevent a hunting and a step-out and make a smooth rotation and then stabilize rotation characteristics by starting up the rotation at the synchronous mode and controlling the rotation at the self-excited mode after a constant rotating speed is obtained. CONSTITUTION:When a motor start-up is instructed, a control circuit 8 detects the instruction and the mode becomes the synchronous one. Then, the control circuit 8 controls the oscillation of a variable oscillator 3 so that a reference pulse of a gradually higher frequency may be output until the frequency becomes a specified one and its also controls a switch 14 so that a selection terminal 14c may select a terminal 14a. By this, a three-phase bidirectional motor 1 works as a synchronous motor. An FG detection circuit 2 generates FG pulses to show the rotating speed of the three-phase bidirectional motor 1 and the control circuit 8 detects the rotating speed of the motor 1 by counting the number of the pulses. When the rotating speed reaches a specified one, the mode becomes the excited one and the switch 14 is so controlled that the selection terminal 14c may select a terminal 14b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor rotation control device suitable for use, for example, in controlling a tape running system of a video tape recorder device.

[0002]

2. Description of the Related Art Conventionally, three-phase windings which are out of phase by 120 degrees, magnet rotators magnetized in three phases corresponding to the respective windings, the positions of the windings and the magnet rotator. A three-phase bidirectional motor is known in which a drive system is composed of a Hall element for detecting polarity.

This three-phase bidirectional motor is designed to be pulse-driven by a drive pulse from a pulse supply circuit. For example, when rotating in the clockwise direction, pulses with a phase difference of 60 degrees in the forward direction are applied. Is supplied. Also, when rotating in the counterclockwise direction, 60 in the negative direction.
Pulses whose phases are shifted by degrees are supplied. At this time, the rotation detection circuit detects the rotation state of the magnet rotator and feeds this detection pulse back to the pulse supply circuit. The pulse supply circuit changes the frequency of the drive pulse so that the rotation speed is set and supplies the drive pulse to the winding.

The Hall element detects the polarity of the magnet rotator due to the rotation and the position of each winding, and supplies the detection output to the pulse supply circuit. The pulse supply circuit switches and controls the polarity of the drive pulse supplied to each winding according to the detection output from the Hall element.

As a result, during the rotation, the switching time for switching the polarity of the drive pulse supplied to the winding can be maintained. Further, since the self-excited system to which the feedback is applied is composed of the Hall element and each winding, smooth rotation can be realized without causing disorder or step out.

On the other hand, conventionally, a so-called synchronous motor is known in addition to such a three-phase bidirectional motor. This synchronous motor does not have a Hall element that detects the positional relationship between the magnet rotator and each winding, and the magnet rotator follows the rotating magnetic field with a certain delay. To do. Since this synchronous motor does not require the Hall element, the so-called DS
Complete digital control by P (digital signal processor) or the like is possible.

[0007]

However, since the three-phase bidirectional motor is configured to detect the positional relationship between the magnet rotator and each winding in an analog manner by using the Hall element, it is completely digitally controlled. However, there is a problem that the above DSP or the like cannot be used.

Further, although the above-mentioned synchronous motor can be completely digitally controlled, it is designed so that the magnet rotator follows the rotation magnetic field with a predetermined delay, so that the delay is greater than a predetermined delay. In that case, there was a problem that step out of disorder occurred and eventually stopped.

The present invention has been made in view of the above problems, and enables complete digital control and smooth rotation without causing out-of-order or out-of-step. It is an object of the present invention to provide a rotation control device for such a motor.

[0010]

A rotation control device for a motor according to the present invention is a rotation control device for a motor for controlling the rotation of a multi-phase motor having no Hall element, and the rotation speed of the motor. And a rotation detecting unit that outputs a rotation detecting pulse, and an oscillating unit that can change the frequency of the oscillating pulse.

Further, a motor drive pulse forming means for forming a motor drive pulse for controlling the motor at a predetermined rotation speed based on the rotation detection pulse from the rotation detecting means and the pulse from the oscillating means, Polarity control means for controlling the polarity of the motor drive pulse from the motor drive pulse forming means, switching means for switching between the pulse from the oscillating means and the motor drive pulse from the polarity control means and supplying the motor. Have.

Further, when the motor is started up, the oscillating means is controlled so as to be in a synchronous mode so that a pulse whose frequency is gradually increased to a predetermined frequency is outputted, and this pulse is supplied to the motor. As described above, the switching means is switched and controlled, the rotation detection pulse number from the rotation detection means is detected, and when the motor reaches a predetermined rotation number, the self-excitation mode is set, and the rotation detection pulse number is changed according to the rotation detection pulse number. The control means controls the polarity control means so as to form a motor drive pulse having a predetermined polarity, and controls the switching means so that the polarity-controlled motor drive pulse is supplied to the motor.

Further, in the motor rotation control device according to the present invention, the motor drive pulse forming means has a pulse width modulating means for forming a motor drive pulse having a pulse width corresponding to the set rotation speed of the motor.

Further, in the motor rotation control device according to the present invention, the motor drive pulse forming means has a pulse amplitude modulating means for forming a motor drive pulse having an amplitude corresponding to the set rotation speed of the motor.

[0015]

The motor rotation control device according to the present invention is a motor rotation control device for controlling the rotation of a multi-phase motor having no hall element, and the control means is synchronized when the motor is started. It becomes a mode.

In this synchronous mode, the control means controls the oscillating means so that a pulse whose frequency gradually increases up to a predetermined frequency is output, and
In order to supply this pulse to the motor, switching control is performed between the pulse from the oscillation means and the switching means to which the motor drive pulse from the polarity control means is supplied.

Thus, when the motor is started up, the motor can be driven as a synchronous motor by the synchronous system.

Further, in parallel with this, the motor drive pulse forming means rotates the motor to a predetermined rotation based on the rotation pulse from the rotation detecting means for detecting the rotation speed of the motor and the pulse from the oscillating means. A motor drive pulse for controlling the number is formed and is supplied to the polarity control means.

Specifically, the motor drive pulse forming means forms a motor drive pulse having a pulse width corresponding to the set rotational speed of the motor and supplies the motor drive pulse to the polarity control means. Alternatively, a motor drive pulse having an amplitude corresponding to the set rotation speed of the motor is formed and supplied to the polarity control means.

Next, the control means detects the number of rotation pulses from the rotation detection means in the synchronous mode. When the rotation pulse number reaches a predetermined pulse number and the motor reaches a predetermined rotation number, the self-excitation mode is set.

When in the self-excited mode, the control means controls the polarity control means so as to form a motor drive pulse having a predetermined polarity according to the number of rotation detection pulses, and outputs from the polarity control means. The switching means is switched and controlled so that the generated motor drive pulse is supplied to the motor.

As a result, the motor can be driven by switching from the synchronous system to the self-excited system. For this reason,
After entering the self-excited mode, stable rotation can be realized without causing out-of-step and out-of-step unlike the synchronous motor. Further, since the polarity of the motor drive pulse supplied to the motor is controlled according to the number of pulses of the rotation detection pulse, a Hall element for detecting the positional relationship between the rotator and the winding of the motor is provided. It can be omitted. Therefore, for example, so-called DSP
(Digital signal processor) or the like enables complete digital control.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a motor rotation control device according to the present invention will be described in detail below with reference to the drawings.

First, as shown in FIG. 1, a rotation control device for a motor according to an embodiment of the present invention is a three-phase bidirectional motor 1.
And a rotation detection circuit 2 (FG) for detecting the number of rotations of the three-phase bidirectional motor 1 and outputting a rotation detection pulse (FG pulse).
Detection circuit) and a variable oscillator 3 that outputs a reference pulse of a set frequency.

Further, by dividing the reference pulse from the variable oscillator 3 into a predetermined frequency, a frequency divider 4 which forms and outputs a divided pulse having the same frequency as the FG pulse from the FG detection circuit 2. And a digital phase comparator 5 for digitally comparing the phases of the FG pulse and the divided pulse and for counting the number of reference pulses from the variable oscillator 3 existing between these phase differences. ing.

Further, a time counter 6 for counting the number of reference pulses from the variable oscillator 3 existing during one cycle of the FG pulse, and a reference counter 7 for counting the number of reference pulses from the variable oscillator 3. Subtractor 10 that detects the difference between the count value from the time counter 6 and the count value from the reference counter 7, and the difference between the count value from the digital phase comparator 5 and the difference output from the subtractor 10. And a subtractor 9 for detecting

Also, a phase compensation circuit 11 for compensating the phase of the differential output from the subtractor 9 and outputting it, and a pulse width modulation pulse are formed by performing pulse width modulation on the output from the phase compensation circuit 11. Output pulse width modulation circuit 1
2 and a polarity control circuit 13 that controls and outputs the polarity of the pulse width modulation pulse.

Further, the reference pulse from the variable oscillator 3 and the pulse width modulation pulse from the polarity control circuit 13 are switched and supplied to the three-phase bidirectional motor 1, and the variable oscillator 3 outputs the pulse. The polarity control circuit 13 controls the frequency of the reference pulse, and based on the FG pulse from the FG detection circuit 2.
And the control circuit 8 for controlling the polarity control state and the switching state of the changeover switch 14.

The three-phase bidirectional motor 1 is provided with three-phase windings, a rotator magnetized in three phases corresponding to the windings, and a notch corresponding to, for example, 360 teeth over the entire circumference. And an FG plate for rotation detection that rotates together with the rotator. In addition,
The three-phase bidirectional motor 1 does not have a Hall element for detecting the positional relationship between the rotator and each winding.

Next, the operation of the motor rotation control device according to this embodiment having such a configuration will be described. First, when the start of rotation is designated, the control circuit 8 detects this and enters the synchronous mode, and controls the oscillation of the variable oscillator 3 so that the reference pulse having a gradually higher frequency is output until a predetermined frequency is reached. The selector switch 14 is controlled so that the selected terminal 14a is selected by the selection terminal 14c.

As a result, the reference pulse from the variable oscillator 3 is supplied to each winding of the three-phase bidirectional motor 1 via the changeover switch 14, and the three-phase bidirectional motor 1 works as a synchronous motor. The rotating magnetic field gradually rises and the rotator and FG plate start to rotate.

When the rotation of the three-phase bidirectional motor 1 is started in this manner, the FG detection circuit 2 operates on the basis of the notches corresponding to 360 teeth provided on the FG plate rotating with the rotator. An FG pulse indicating the rotation speed of the bidirectional motor 1 is formed, and this is supplied to the digital phase comparator 5 and the control circuit 8.

The control circuit 8 counts the number of FG pulses to generate the three-phase bidirectional motor 1.
Detects the number of rotations of. Then, when the rotation speed reaches a predetermined rotation speed, the self-excitation mode is set, and the changeover switch 14 is controlled so as to select the selected terminal 14b by the selection terminal 14c.

On the other hand, F rotating together with the rotator
The FG pulse formed by the FG detection circuit 2 by detecting the cutout of the G plate is supplied to the control circuit 8 and the digital phase comparator 5 and the time counter 6.

In the digital phase comparator 5, the three-phase bidirectional motor 1 is set in a set rotational state, which is formed by dividing the reference pulse of the predetermined frequency from the variable oscillator 3 by the frequency divider 4. Then, the divided pulse having the same frequency as that of the FG pulse obtained when the frequency becomes zero is supplied. Further, the reference pulse from the variable oscillator 3 is supplied to the digital phase comparator 5.

The digital phase comparator 5 is shown in FIG.
A divided pulse as shown in FIG. 2 and F as shown in FIG.
By comparing the phase with the G pulse, the phase error TP between the divided pulse and the FG pulse is detected. Then, by counting the number of reference pulses existing between the phase errors TP, a count value indicating the phase error of the FG pulse related to the set rotation speed of the three-phase bidirectional motor 1 is formed, and this is calculated. It is supplied to the subtractor 9.

The time counter 6 counts the number of reference pulses existing during one period Tfg of the FG pulse shown in FIG. 2B, and supplies this count value to the subtractor 10. Further, the reference counter 7 has the above 3
The number of reference pulses within a predetermined period according to the number of rotations of the bidirectional motor 1 is counted, and this count value is supplied to the subtractor 10.

The subtractor 10 includes the time counter 6
By detecting the difference between the count value from the reference counter 7 and the count value from the reference counter 7, a count value indicating the frequency error of the FG pulse relating to the set rotation speed of the three-phase bidirectional motor 1 is formed, This is supplied to the subtractor 9.

The subtractor 9 detects the difference between the count value indicating the phase error of the FG pulse from the digital phase comparator 5 and the count value indicating the frequency error of the FG pulse from the subtractor 10. Thus, a count value indicating the phase error and the frequency error is formed, and the count value is supplied to the phase compensation circuit 11.

The phase compensating circuit 11 performs a phase compensating process on the count value indicating the phase error and the frequency error,
This is supplied to the pulse width modulation circuit 12.

The pulse width modulation circuit 12 is supplied from the control circuit 8 with rotation control data for setting the three-phase bidirectional motor 1 at a set rotation speed. The pulse width modulation circuit 12 responds to the rotation control data by
By performing pulse width modulation processing on the count values indicating the phase error and the frequency error, a pulse width modulated pulse having a pulse width capable of achieving the set rotational speed is formed, and the pulse width modulated pulse is formed. Supply to 13.

As will be described later, the polarity control circuit 13 supplies polarity control data from the control circuit 8 for controlling the polarity of the pulse width modulation pulse supplied to each winding of the three-phase bidirectional motor 1. Is being supplied. The polarity control circuit 13 inverts the polarity of the pulse width modulation pulse according to the polarity control data and supplies it to the selected terminal 14b of the changeover switch 14.

As described above, in the self-excited mode, the changeover switch 14 is controlled by the control circuit 8 so that the selection terminal 14c selects the selection terminal 14b. Therefore, the pulse width modulation pulse from the polarity control circuit 13 is supplied to each winding of the three-phase bidirectional motor 1 via the changeover switch 14. Thus, the three-phase bidirectional motor 1 can be rotationally controlled at the set rotational speed.

Since the Hall element is not provided in the three-phase bidirectional motor 1 as described above, the positional relationship between the rotator and each winding cannot be detected.
Therefore, in the motor rotation control device according to the present embodiment,
The polarity of the current supplied to each winding is switched by counting the number of FG pulses.

That is, when controlling the rotation of the three-phase bidirectional motor 1 in the clockwise direction, for example, the control shown in the flowchart of FIG. 3 is performed. In the flowchart shown in FIG. 3, when the FG pulse shows a predetermined rotation speed, the control circuit 8 switches from the synchronous mode to the self-excited mode, and the rotation control in the clockwise direction is designated. Starts at step S1 and proceeds to step S1.

In step S1, the control circuit 8
However, the counting of the number of FG pulses in the predetermined period is started, and the process proceeds to step S2.

In step S2, the control circuit 8
Discriminates whether or not the number of FG pulses (Nfg) within the predetermined period is 60 or less. If NO, the process proceeds to step S4, and if YES, the process proceeds to step S3.

In step S3, the control circuit 8
However, the polarity control data for controlling the polarity of the pulse width modulation pulse supplied to the first winding of the three-phase bidirectional motor 1 to be negative (-), the polarity of the pulse width modulation pulse supplied to the second winding is positive. The polarity control circuit 1 controls the polarity control data for controlling (+) and the polarity control data for controlling the polarity of the pulse width modulation pulse supplied to the third winding to be negative (-).
3 and the process returns to step S2. Then, the control circuit 8 continues to supply the polarity control data described above to the polarity control circuit 13 until it is determined in step S2 that the FG pulse number is 61 or more.

Next, when it is determined in step S2 that the number of FG pulses in the predetermined period is 61 or more, the process proceeds to step S4. In step S4, the control circuit 8 determines whether or not the number of FG pulses in the predetermined period is 120 or less. If NO, the process proceeds to step S6, and if YES, step S5.
Proceed to.

In step S5, the control circuit 8 is
However, the polarity control data for controlling the polarity of the pulse width modulation pulse supplied to the first winding of the three-phase bidirectional motor 1 to be negative (-), the polarity of the pulse width modulation pulse supplied to the second winding is positive. The polarity control circuit 1 controls the polarity control data for controlling (+) and the polarity control data for controlling the polarity of the pulse width modulation pulse supplied to the third winding to be positive (+).
3 and the process returns to step S4. Then, the control circuit 8 continues to supply the polarity control data described above to the polarity control circuit 13 until it is determined in step S4 that the FG pulse number is 121 or more.

Next, if it is determined in step S4 that the number of FG pulses in the predetermined period is 121 or more, the process proceeds to step S6. This step S6
Then, the control circuit 8 controls the FG within the predetermined period.
It is determined whether the number of pulses is 180 or less. If NO, the process proceeds to step S8, and if YES, the step S8.
Proceed to 7.

In step S7, the control circuit 8
However, the polarity control data for controlling the polarity of the pulse width modulation pulse supplied to the first winding of the three-phase bidirectional motor 1 to be negative (-), the polarity of the pulse width modulation pulse supplied to the second winding is negative. The polarity control circuit 1 controls the polarity control data for controlling (-) and the polarity control data for controlling the polarity of the pulse width modulation pulse supplied to the third winding to be positive (+).
3 and the process returns to step S6. The control circuit 8 continues to supply the polarity control data to the polarity control circuit 13 until it is determined in step S6 that the FG pulse number is 181 or more.

Next, if it is determined in step S6 that the number of FG pulses in the predetermined period is 181 or more, the process proceeds to step S8. This step S8
Then, the control circuit 8 controls the FG within the predetermined period.
It is determined whether or not the number of pulses is 240 or less. If NO, the process proceeds to step S10, and if YES, the process proceeds to step S9.

In step S9, the control circuit 8
However, the polarity control data for controlling the polarity of the pulse width modulation pulse supplied to the first winding of the three-phase bidirectional motor 1 to be positive (+), and the polarity of the pulse width modulation pulse supplied to the second winding are negative. The polarity control circuit 1 controls the polarity control data for controlling (-) and the polarity control data for controlling the polarity of the pulse width modulation pulse supplied to the third winding to be positive (+).
3 and the process returns to step S8. Then, the control circuit 8 continues to supply the polarity control data to the polarity control circuit 13 until it is determined in step S8 that the FG pulse number is 241 or more.

Next, when it is determined in step S8 that the number of FG pulses in the predetermined period is 241 or more, the process proceeds to step S10. This step S
At 10, the control circuit 8 determines whether the number of FG pulses in the predetermined period is 300 or less, and N
If it is O, the process proceeds to step S12, and if it is YES, the process proceeds to step S11.

In step S11, the control circuit 8
However, the polarity control data for controlling the polarity of the pulse width modulation pulse supplied to the first winding of the three-phase bidirectional motor 1 to be positive (+), and the polarity of the pulse width modulation pulse supplied to the second winding are negative. The polarity control circuit 1 controls the polarity control data for controlling (-) and the polarity control data for controlling the polarity of the pulse width modulation pulse supplied to the third winding to be negative (-).
3 and the process returns to step S10. Then, the control circuit 8 continues to supply the polarity control data described above to the polarity control circuit 13 until it is determined in step S10 that the FG pulse number is 301 or more.

Next, if it is determined in step S10 that the number of FG pulses in the predetermined period is 301 or more, the process proceeds to step S12. In step S12, the control circuit 8 determines whether or not the number of FG pulses in the predetermined period is 360 or less,
If NO, the process proceeds to step S14, and if YES, the process proceeds to step S13.

In step S13, the control circuit 8
However, the polarity control data for controlling the polarity of the pulse width modulation pulse supplied to the first winding of the three-phase bidirectional motor 1 to be positive (+) is used as the polarity control data of the pulse width modulation pulse supplied to the second winding. The polarity control circuit 1 controls the polarity control data for controlling (+) and the polarity control data for controlling the polarity of the pulse width modulation pulse supplied to the third winding to be negative (-).
3 and the process returns to step S12. Then, the control circuit 8 continues to supply the polarity control data described above to the polarity control circuit 13 until it is determined in step S12 that the number of FG pulses exceeds 360.

Next, when it is determined in step S12 that the number of FG pulses in the predetermined period exceeds 360, the control circuit 8 proceeds to step S14,
The counter value is reset to 0, the process returns to step S1 and the counting of the FG pulse number is started again.

Such steps S1 to S14
The routine for controlling the rotation of the three-phase bidirectional motor 1 in the clockwise direction shown in FIG. 2 is specified to stop the rotation of the three-phase bidirectional motor 1 or to specify the counterclockwise rotation described below. It continues until it is done.

Next, when controlling the rotation of the three-phase bidirectional motor 1 in the counterclockwise direction, for example, the control shown in the flowchart of FIG. 4 is performed. In the flow chart shown in FIG. 4, the FG pulse shows a predetermined rotation speed, the control circuit 8 switches from the synchronous mode to the self-excited mode, and the counterclockwise rotation control is designated. It sometimes starts and proceeds to step S21.

In step S21, the control circuit 8
However, the counting of the number of FG pulses in the predetermined period is started, and the process proceeds to step S22.

In step S22, the control circuit 8 is
Discriminates whether or not the number of FG pulses (Nfg) within the predetermined period is 60 or less. If NO, the process proceeds to step S24, and if YES, the process proceeds to step S23.

In step S23, the control circuit 8
However, the polarity control data for controlling the polarity of the pulse width modulation pulse supplied to the first winding of the three-phase bidirectional motor 1 to be negative (-), the polarity of the pulse width modulation pulse supplied to the second winding is negative. The polarity control circuit 1 controls the polarity control data for controlling (-) and the polarity control data for controlling the polarity of the pulse width modulation pulse supplied to the third winding to be positive (+).
3 and the process returns to step S22. The control circuit 8 continues to supply the polarity control data to the polarity control circuit 13 until it is determined in step S22 that the FG pulse number is 61 or more.

Next, in step S22, if it is determined that the number of FG pulses in the predetermined period is 61 or more, the process proceeds to step S24. This step S
At 24, the control circuit 8 determines whether or not the number of FG pulses in the predetermined period is 120 or less, and N
If it is O, the process proceeds to step S26, and if it is YES, the process proceeds to step S25.

In step S25, the control circuit 8
However, the polarity control data for controlling the polarity of the pulse width modulation pulse supplied to the first winding of the three-phase bidirectional motor 1 to be negative (-), the polarity of the pulse width modulation pulse supplied to the second winding is positive. The polarity control circuit 1 controls the polarity control data for controlling (+) and the polarity control data for controlling the polarity of the pulse width modulation pulse supplied to the third winding to be positive (+).
3 and the process returns to step S24. Then, the control circuit 8 continues to supply the polarity control data to the polarity control circuit 13 until it is determined in step S24 that the FG pulse number is 121 or more.

Next, in step S24, if it is determined that the number of FG pulses in the predetermined period is 121 or more, the process proceeds to step S26. In step S26, the control circuit 8 determines whether the number of FG pulses in the predetermined period is 180 or less,
If NO, the process proceeds to step S28, and if YES, the process proceeds to step S27.

In step S27, the control circuit 8
However, the polarity control data for controlling the polarity of the pulse width modulation pulse supplied to the first winding of the three-phase bidirectional motor 1 to be negative (-), the polarity of the pulse width modulation pulse supplied to the second winding is positive. The polarity control circuit 1 controls the polarity control data for controlling (+) and the polarity control data for controlling the polarity of the pulse width modulation pulse supplied to the third winding to be positive (+).
3 and the process returns to step S26. Then, the control circuit 8 continues to supply the polarity control data described above to the polarity control circuit 13 until it is determined in step S26 that the number of FG pulses is 181 or more.

Next, when it is determined in step S26 that the number of FG pulses in the predetermined period is 181 or more, the process proceeds to step S28. In step S28, the control circuit 8 determines whether or not the number of FG pulses in the predetermined period is 240 or less,
If NO, the process proceeds to step S30, and if YES, the process proceeds to step S29.

In step S29, the control circuit 8
However, the polarity control data for controlling the polarity of the pulse width modulation pulse supplied to the first winding of the three-phase bidirectional motor 1 to be positive (+) is used as the polarity control data of the pulse width modulation pulse supplied to the second winding. The polarity control circuit 1 controls the polarity control data for controlling (+) and the polarity control data for controlling the polarity of the pulse width modulation pulse supplied to the third winding to be negative (-).
3 and the process returns to step S28. The control circuit 8 continues to supply the polarity control data to the polarity control circuit 13 until it is determined in step S28 that the FG pulse number is 241 or more.

Next, when it is determined in step S28 that the number of FG pulses in the predetermined period is 241 or more, the process proceeds to step S30. In step S30, the control circuit 8 determines whether the number of FG pulses in the predetermined period is 300 or less,
If NO, the process proceeds to step S32, and if YES, the process proceeds to step S31.

In step S31, the control circuit 8
However, the polarity control data for controlling the polarity of the pulse width modulation pulse supplied to the first winding of the three-phase bidirectional motor 1 to be positive (+), and the polarity of the pulse width modulation pulse supplied to the second winding are negative. The polarity control circuit 1 controls the polarity control data for controlling (-) and the polarity control data for controlling the polarity of the pulse width modulation pulse supplied to the third winding to be negative (-).
3 and the process returns to step S30. Then, the control circuit 8 continues to supply the polarity control data described above to the polarity control circuit 13 until it is determined in step S30 that the FG pulse number is 301 or more.

Next, if it is determined in step S30 that the number of FG pulses in the predetermined period is 301 or more, the process proceeds to step S32. In step S32, the control circuit 8 determines whether or not the number of FG pulses in the predetermined period is 360 or less,
If NO, the process proceeds to step S34, and if YES, the process proceeds to step S33.

In step S33, the control circuit 8
However, the polarity control data for controlling the polarity of the pulse width modulation pulse supplied to the first winding of the three-phase bidirectional motor 1 to be positive (+), and the polarity of the pulse width modulation pulse supplied to the second winding are negative. The polarity control circuit 1 controls the polarity control data for controlling (-) and the polarity control data for controlling the polarity of the pulse width modulation pulse supplied to the third winding to be positive (+).
3 and the process returns to step S32. Then, the control circuit 8 continues to supply the polarity control data to the polarity control circuit 13 until it is determined in step S32 that the FG pulse number exceeds 360.

Next, when it is determined in step S32 that the number of FG pulses in the predetermined period exceeds 360, the control circuit 8 proceeds to step S34,
The counter value is reset to 0, the process returns to step S21, and the counting of the FG pulse number is started again.

Such steps S21 to S3
The routine shown in 4 for controlling the rotation of the three-phase bidirectional motor 1 in the counterclockwise direction is the three-phase bidirectional motor 1
Is stopped until the rotation is designated, or the above-mentioned clockwise rotation is designated.

As described above, the motor rotation control apparatus according to the present embodiment enters the synchronous mode at the start of rotation, starts up the rotation by using the three-phase bidirectional motor 1 as a synchronous motor, and the three-phase bidirectional motor 1 is activated. , When the rotational speed reaches a predetermined rotational speed, the self-excitation mode is set, and the pulse width modulation pulse supplied to each winding of the three-phase bidirectional motor 1 is changed according to the rotational speed (FG pulse number) of the three-phase bidirectional motor 1. Control polarity.

Therefore, after the self-excited mode is set,
Smooth rotation can be maintained without the occurrence of out-of-control or step-out as in a synchronous motor, and the rotation characteristics can be stabilized.

Further, since the polarity of the pulse width modulation pulse supplied to each winding of the three-phase bidirectional motor 1 is controlled according to the number of revolutions of the three-phase bidirectional motor 1, the rotator and each of the rotators are provided by using Hall elements. The polarity of the pulse width modulation pulse supplied to each winding can be controlled without detecting the positional relationship between the windings. Therefore, the portion that detects the positional relationship between the rotator and each winding can be digitized. Therefore, for example, a complete digital control can be performed by a so-called DSP (digital signal processor) or the like.

In the above description of the embodiment, the control circuit 8 drives the three-phase bidirectional motor 1 in pulse width modulation (PWM). Pulse amplitude modulation drive (PAM) for controlling the voltage applied to the three-phase bidirectional motor 1 may be performed. Further, the three-phase bidirectional motor 1 is provided as the polyphase motor, but this may be a two-phase motor, a six-phase motor or the like as long as there is no Hall element.

Further, the rotation control device for the motor is, for example, a linear brushless motor and a rotation speed detecting means (F
Of course, it can be applied to the rotation control of a motor having a G plate), a rotator, and a winding.

[0082]

The motor rotation control device according to the present invention comprises:
Since a Hall element for detecting the positional relationship between the winding and the magnet rotator is not required, so-called DSP
(Digital signal processor) or the like enables complete digital control.

Further, since the rotation is started in the synchronous mode and a constant rotational speed is obtained, the rotation can be controlled in the self-excited mode. Without this, smooth rotation can be realized and the rotation characteristics can be stabilized.

[Brief description of drawings]

FIG. 1 is a block diagram of a rotation control device for a motor according to an embodiment of the present invention.

FIG. 2 is a time chart for explaining a rotation servo operation of the motor rotation control device according to the embodiment.

FIG. 3 is a flowchart of forward rotation control in the motor rotation control device according to the embodiment.

FIG. 4 is a flowchart of negative direction rotation control in the motor rotation control device according to the embodiment.

[Explanation of symbols]

 1 3 phase bidirectional motor (without Hall element) 2 rotation detection circuit 3 variable oscillator 4 frequency divider 5 digital phase comparator 6 time counter 7 reference counter 8 control circuit 9, 10 subtractor 11 phase compensation circuit 12 pulse modulation circuit 13 polarity Control circuit 14 changeover switch

Claims (3)

[Claims] 1. A rotation control device for a motor for controlling rotation of a multi-phase motor having no Hall element, comprising: rotation detection means for detecting a rotation speed of the motor and outputting a rotation detection pulse. An oscillating means in which the frequency of the oscillating pulse is variable, and a motor drive pulse for controlling the motor to a predetermined number of revolutions based on the rotation detecting pulse from the rotation detecting means and the pulse from the oscillating means. The motor drive pulse forming means, the polarity control means for controlling the polarity of the motor drive pulse from the motor drive pulse forming means, the pulse from the oscillation means, and the motor drive pulse from the polarity control means. The switching means for supplying to the motor and the synchronous mode when the motor is started up so that the frequency gradually increases to a predetermined frequency. The oscillation means is controlled so that a pulse is output, and the switching means is controlled so that the pulse is supplied to the motor, and the number of rotation detection pulses from the rotation detection means is detected to detect the motor. Becomes a predetermined rotation speed, the self-excitation mode is set, and the polarity control means is controlled so as to form a motor drive pulse having a predetermined polarity in accordance with the rotation detection pulse count, and the polarity-controlled motor is controlled. A rotation control device for a motor, comprising: a control unit that controls switching of the switching unit so that a drive pulse is supplied to the motor. 2. The motor according to claim 1, wherein the motor drive pulse forming means has a pulse width modulating means for forming a motor drive pulse having a pulse width according to the number of rotations of the motor to be set. Rotation control device. 3. The rotation of the motor according to claim 1, wherein the motor drive pulse forming means has a pulse amplitude modulating means for forming a motor drive pulse having an amplitude according to the set rotation speed of the motor. Control device.