JPH099669A - Motor rotation control device - Google Patents

Abstract

(57) [Summary] [Purpose] The speed of rotation is kept constant by performing accurate speed control against fluctuations in the speed of rotation that are detected due to errors unique to the motor, such as the placement error of each magnetic pole of the motor. A value of each phase error signal between a plurality of rotation detection signals generated within one rotation of the motor 1 and a reference signal is stored in a memory in advance, and the motor rotates and each phase error is output from the phase comparator. When the signal is output, the rotation speed is controlled based on each output signal and each value of the memory corresponding to each output signal. As a result, even if an error signal is generated due to speed fluctuation caused by an error peculiar to the motor, the error signal can be canceled by the value stored in the memory, and therefore unnecessary acceleration and deceleration are not performed on the motor. The power consumption of the device can be reduced, and the rotation of the device can be controlled at a constant speed.

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 for controlling the rotation of a motor at a constant speed.

[0002]

2. Description of the Related Art As a control device for keeping the rotation speed of a motor constant, there is a device as shown in FIG. Further, FIG. 4 shows operation waveforms of respective parts of such a control device. In FIG. 3, 1 is a motor, 2 is a Hall sensor, 3 is an edge detection circuit, 4 is a phase comparator, and 5 is a drive circuit for driving the motor 1. Here, the motor 1 is configured such that a rotor having four magnetic poles (S, N, S, N) rotates. The hall sensor 2 provided in the motor 1 detects the above-mentioned magnetic pole passing by the rotation of the rotor. When the magnetic pole is switched from the S pole to the N pole or from the N pole to the S pole, this is detected. Change the output signal level. FIG. 4A shows the situation of the output signal a of the Hall sensor 2 as described above.

As shown in FIG. 4B, the edge detection circuit 3 which receives the output signal a of the Hall sensor 2 outputs a pulse signal b at the rising time and the falling time of the output signal a, respectively, This pulse signal b is sent to one input terminal of the phase comparator 4. Here, the phase comparator 4
The reference phase signal c shown in FIG. 4 (c) is applied to the other input terminal of the phase detector 4, and when the above-mentioned pulse signal b is applied from the edge detection circuit 3, the phase comparator 4 operates as shown in FIG. )
The phase error signal d indicating the phase error between both signals is output to the drive circuit 5 as shown in FIG.

Even when there is no phase difference between the phase of the pulse signal b of the edge detection circuit 3 and the phase of the reference phase signal c, it is necessary to continue driving the motor 1. , The minute signals d1 and d3 shown in FIG. 4D are output to the drive circuit 5. The drive circuit 5 controls the rotation speed of the motor 1 based on the phase error signal d so that the phase error becomes zero.

That is, the rotation of the motor 1 rises, and
When the pulse width of the output signal a in (a) becomes short, for example, when the “0” level shown in FIG. 4D is used as a reference value, the phase comparator 4 is negative (“−”) with respect to this reference value. The level phase error signal d2 is output to the drive circuit 5 to decelerate the motor 1. When the rotation of the motor 1 decreases and the pulse width of the output signal a becomes longer, the phase error signal d4 of the positive (“+”) level with respect to the reference value is output to the drive circuit 5 to accelerate the motor 1. In this way, the motor rotation control device controls the rotation of the motor 1 at a constant speed.

[0006]

However, if the magnetic poles are not evenly divided in the rotor of the motor 1 and there is an error in the divided positions of the magnetic poles, even if the speed control as described above is performed, The rotation cannot be kept constant. The reason for this is that even if the motor 1 is rotating at a constant speed,
If there is the above error, the output signal a of the Hall sensor 2 becomes
This is because, for example, as shown in FIG. 4A, the time widths T1, T2, T3 of the pulses corresponding to the magnetic poles N, S, N are different. Therefore, the phase difference between the output signal b of the edge detection circuit 3 and the reference phase signal c does not become zero, and the phase error similar to the phase error signals d2 and d4 shown in FIG. A signal is generated.

Therefore, although the rotation speed of the motor 1 is actually stable, the phase error signal d is sent to the drive circuit 5 as if the rotation speed of the motor 1 were changing. The drive signal e shown in FIG. 4E for changing the rotation speed of the motor 1 is output from the drive circuit 5, and as a result, the rotation speed of the motor 1 is changed to that shown in FIG.
There is a problem that it becomes unstable as shown in (f).
In addition, in this case, the drive circuit 5 performs unnecessary acceleration or deceleration with respect to the motor 1, resulting in a problem that unnecessary power is consumed. Therefore, an object of the present invention is to accurately control the speed of rotation fluctuations detected due to errors unique to the motor, such as an error in the arrangement of the magnetic poles of the motor, and to keep the rotation speed constant.

[0008]

In order to solve such a problem, the present invention provides a rotation detector for outputting a plurality of detection signals at a predetermined cycle every time the motor makes one rotation, a detection signal and a reference. A phase comparator that compares the phase with a signal and outputs a phase error signal, a memory that stores a value corresponding to the phase error signal in advance, and a motor that is based on the output signal of the phase comparator and the value stored in the memory And a drive circuit for controlling the rotation speed of the. Further, a phase comparator that compares the phases of a plurality of detection signals and a reference signal to each other and outputs a plurality of phase error signals, and the value of the phase error signal for each of the plurality of detection signals is stored in advance in each. And a drive circuit for controlling the rotation speed of the motor based on the output signal of the phase comparator and the value of the memory corresponding to this output signal. Also, a memory connected to the phase comparator for storing the output value of the phase comparator, and a drive circuit for controlling the rotation speed of the motor based on the output signal newly output from the phase comparator and the value stored in the memory. And are provided. Further, a subtractor for subtracting the value of the memory from the output signal of the phase comparator is provided in the preceding stage of the drive circuit, and the drive circuit controls the rotation speed of the motor according to the subtraction result of the subtractor. .

[0009]

The value of the phase error signal between the motor rotation detection signal and the reference signal is stored in the memory in advance. When the motor rotates and the phase error signal is output from the phase comparator, the output signal and the memory are output. The rotation speed is controlled based on the value of and.
As a result, even if the phase error signal is generated due to the fluctuation of the rotation speed due to the error peculiar to the motor, such as the error in the arrangement of each magnetic pole of the motor, the error signal can be canceled by the value in the memory. Since unnecessary acceleration or deceleration of the motor is not performed, the power consumption of the device can be reduced and the rotation of the motor can be controlled to be constant. Further, the values of the phase error signals between the plurality of rotation detection signals and the reference signal generated within one rotation of the motor are stored in the memory in advance, respectively, and the motor is rotated to output the phase error signals from the phase comparator. Is output, the rotation speed is controlled based on each output signal and each value of the memory corresponding to each output signal. As a result, when the rotation speed of the motor is controlled to be constant, since the rotation control can be performed for each detection signal, accurate control can be performed. Further, the value of the output signal of the phase comparator is stored in the memory, and when a new signal is output from the phase comparator, the rotation speed of the motor is controlled based on this signal and the value stored in the memory. As a result, even if the rotation of the motor changes due to secular change or the like, accurate rotation control can be performed by automatically updating the memory contents at any time without resetting the memory value. The subtractor subtracts the value in the memory from the output signal (phase error signal) of the phase comparator, and outputs the subtraction result to the drive circuit. As a result, the speed of the motor can be easily controlled by the drive circuit.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a motor rotation control device according to the present invention. In the figure, the motor 1, the hall sensor 2, the edge detection circuit 3, the phase comparator 4, and the drive circuit 5 have the same configuration as the conventional device shown in FIG. In addition to this, in the apparatus of this embodiment, the memory 6,
Selector 7, selection circuit 8, subtractor 9 and weighting circuit 1
0 is provided. Further, FIG. 2 is a diagram showing operation waveforms of the respective parts of the apparatus of this embodiment. The operation of the apparatus of this embodiment will be described in detail with reference to FIGS.

The motor 1 is constructed so that the rotor having four magnetic poles (S, N, S, N) rotates as described above. Hall sensor 2 provided on the motor 1
Is rotated from the south pole to the north pole as the rotor rotates.
When the pole or the N pole is switched to the S pole, the level of the output signal a is changed as shown in FIG. 2A in conjunction with this switching. That is, when the motor 1 makes one rotation, the output level of the signal a output from the hall sensor 2 changes four times corresponding to each of the four magnetic poles. For example, the N pole, S pole, N pole, Corresponding to the S pole, the level changes to "H" level, "L" level, "H" level, "L" level.

The edge detection circuit 3 to which the output signal a of the hall sensor 2 is input outputs a pulse signal b at the rising time and the falling time of the output signal a, as shown in FIG. 2B. Then, the pulse signal b generated four times per one rotation of the motor 1 is sent to one input terminal of the phase comparator 4. The other input terminal of the phase comparator 4 is supplied with the reference phase signal c shown in FIG. 2 (c), and when the above-mentioned pulse signal b is supplied from the edge detection circuit 3, it is shown in FIG. 2 (d). The phase error signal d indicating the phase difference between the two signals is output to the subtractor 9. The subtracter 9 subtracts the average value of the phase error signals stored in advance in the memory 6 from the phase error signal d and gives the subtraction result to the drive circuit 5 to control the rotation of the motor 1.

By the way, the average value of the phase error signal is stored in the memory 6 as follows. That is, the motor 1 is rotated in advance for a certain period of time, and the average value for each phase error signal corresponding to the above-mentioned four magnetic poles of the motor 1 via the Hall sensor 2, the edge detection circuit 3 and the phase comparator 4 is obtained and obtained. The four average value data are stored in the corresponding four areas of the memory 6, respectively. It should be noted that the above-mentioned fixed period may be a period required for at least one rotation of the motor, but it is needless to say that a certain long period (time required for a plurality of rotations of the motor 1) is more reliable. .

Here, when each average value data stored in each area of the memory 6 is given to the subtractor 9, 1 of the motor 1 is used.
The output signal a and the reference phase signal c of the Hall sensor 2 whose level fluctuates four times during rotation are output to the selection circuit 8. The selection circuit 8 switches the selector 7 either at the time when the level of the output signal a is switched or at the rise of the reference phase signal c. Then, 4 in memory 6
The average value data of one area is extracted for each and
The difference signal f shown in (e) is output to the subtractor 9 side through the weighting circuit 10.

That is, when the motor 1 is rotated in advance, the magnetic poles of the motor 1 as shown in FIG. 2D are changed at the time of switching of each level of the output signal a of the hall sensor 2 or the rising of the reference phase signal c. Corresponding phase error signals d1 to d
4 is generated, the average value of the level is obtained for each of these signals and stored in each of the first to fourth areas of the memory 6 as a digital value. In this case, the phase error signal d
Since 1 and d3 are minute signals, their values are stored as zero in the first and third areas, and the values corresponding to the signals f2 and f4 in FIG. 2E are stored in the second and fourth areas. (Value including the phase difference pulse width) are stored. That is, the reference phase signal c is added to the pulse signal b output from the edge detection circuit 3.
Is delayed (in the case of the phase error signal d2), the digital value consisting of the phase difference between both signals and the sign of "-" is stored in the memory 6
When the reference phase signal c advances with respect to the pulse signal b (in the case of the phase error signal d4) stored in the second area of the digital signal, the digital value including the phase difference between both signals and the sign of “+” is 4 areas are stored.

When the device actually operates and the motor 1 rotates, the phase error signals d1 to d4 corresponding to the magnetic poles from the phase comparator 4 as shown in FIG. 2D are sequentially output. By the control of the selection circuit 8 described above, the values of the difference signals corresponding to zero, signal f2, zero, and signal f4 from the first to fourth regions of the memory 6 corresponding to the signals d1 to d4, respectively. The signals are sequentially taken out, converted into the analog signal shown in FIG. 2 (e), and output to the subtractor 9. The subtractor 9 takes the difference between this difference signal and the phase error signal actually output from the phase comparator 4 and gives it to the drive circuit 5. The drive circuit 5 controls the rotation speed of the motor 1 based on the difference signal subtracted by the subtractor 9 so that the difference signal becomes zero.

Here, even though the rotation speed of the motor 1 is actually stable, it is as if the rotation speed of the motor 1 fluctuates due to an error in the division position of each magnetic pole of the rotor of the motor 1. The erroneous phase error signal d is shown in FIG.
When output as shown in (d), this phase error signal d
Is a difference signal f stored in the memory 6 in advance and shown in FIG.
Is the same as Therefore, the phase error signal d
When the difference signal f of FIG. 2 (e) is subtracted from it, it becomes zero and this difference signal of zero is given to the drive circuit 5 (however,
For example, since minute signals such as d1 and d3 in FIG. 2D are given), the drive circuit 5 may continue to output a constant drive signal g as shown in FIG. Since unnecessary acceleration and deceleration are unnecessary, unnecessary power consumption is avoided and the rotation speed of the motor 1 is kept constant as shown in FIG. 2 (g).

In this embodiment, the difference signal f is stored in the memory 6 in advance, and when the phase comparator 4 outputs the phase error signal d when the motor 1 rotates, the difference signal f is output from the phase error signal d. Is subtracted, the phase error signal d output from the phase comparator 4 the previous time (for example, one rotation before) is stored in the memory 6
Alternatively, the previous phase error signal in the memory 6 may be subtracted from the phase error signal output by the phase comparator 4 this time. That is, on the input side of the memory 6 of FIG.
Is added, and the output of the phase comparator 4 is connected as the input of the selector 11. Then, the selector 11 is configured to be switched by the control of the selection circuit 8.

Here, the selection circuit 8 first switches and controls the selector 7 as described above by either the switching timing of each level of the output signal a or the reference phase signal c, and the difference from the memory 6 one rotation before. The value of the signal f is taken out and sent to the subtractor 9. At the same time, the selection circuit 8 controls the switching of the selector 11 to store the present output (phase error signal) of the phase comparator 4 in the corresponding area of the memory 6. That is, when such switching control for the selector 11 of the selection circuit 8 is performed,
When the phase error signal output this time from the phase comparator 4 is, for example, as shown in FIG. 2D, since the phase error signals d1 and d3 are minute signals, the first and third areas of the memory 6 are Its value is stored as zero and the phase error signals d2, d
4 is stored in the second and fourth areas as values corresponding to the difference signals f2 and f4 in FIG.

The value of the phase error signal thus stored in each area of the memory 6 is read at the next rotation of the motor 1, subtracted from the phase error signal generated by the rotation, and given to the drive circuit 5. With the above configuration, even if the rotation of the motor 1 changes due to secular change or the like, the memory contents are automatically updated at any time without resetting the value of the memory 6. As a result, accurate rotation control can be performed.

Next, when the phase error signal d as shown in FIG. 3D is being output due to the error in the divided position of each magnetic pole of the rotor of the motor 1, the rotational speed of the motor 1 is actually changed. In that case, the phase error signal d further changes in the waveform shown in FIG. Therefore, in this case, only the difference from the difference signal f of FIG. 2 (e) stored in the memory 6 is transmitted to the drive circuit 5, and the drive circuit 5 performs the acceleration or deceleration control according to this difference to the motor 1. To do.

Further, when the divided position of each magnetic pole of the rotor of the motor 1 is normal, the rotation speed of the motor 1 fluctuates and the phase error signal d is output as a signal as shown in FIG. 2D, for example. In this case, the value of the difference signal f stored in each area of the memory 6 in advance is zero, and the signal does not have the waveform as shown in FIG. Therefore, when the subtracter 12 takes the difference between these two signals and outputs it to the drive circuit 5,
The phase error signal of (d) is given to the drive circuit 5 as it is. Therefore, in this case, the drive circuit 5 is shown in FIG.
The acceleration or deceleration control according to the phase error signal of (d) is performed on the motor 1.

In this embodiment, the value of the difference signal f stored in the memory 6 is given to the subtractor 9 as it is. However, in practice, when the value is large, the weighting circuit 10 causes The value is divided and given at multiple times. That is, when the difference signal f2 of FIG. 2 (e) is applied to the subtractor 9, for example, f2 / 2 is given at the timing of the first time (first rotation), and the difference signal f is received at the second time (second rotation). F2 / 4 of the last three times (3
F2 / 4 of the difference signal is applied to the second rotation. As a result, in the rotation control of the motor 1, rapid acceleration or deceleration is not performed, the change amount of the rotation speed is reduced, and the control can be smoothly performed.

[0024]

As described above, according to the present invention, the value of the phase error signal between the rotation detection signal of the motor and the reference signal is stored in the memory in advance, and the motor is rotated and the phase is detected by the phase comparator. When the error signal is output, the rotation speed is controlled based on this output signal and the value in the memory.Therefore, there are variations in the rotation speed due to errors unique to the motor, such as the placement error of each magnetic pole of the motor. Even if a phase error signal is generated, the error signal can be canceled by the memory value. Therefore, in such a case, unnecessary acceleration or deceleration of the motor is not performed, so that the power consumption of the device can be reduced and the motor can be reduced. The rotation of can be controlled to be constant. Also,
The value of each phase error signal between each of the plurality of rotation detection signals generated within one rotation of the motor and the reference signal is stored in the memory in advance, and the motor rotates to output each phase error signal from the phase comparator. Then, since the rotation speed is controlled based on each output signal and each value of the memory corresponding to each output signal, when controlling the rotation speed of the motor to be constant, Since rotation control can be performed, accurate control can be performed. In addition, the value of the output signal of the phase comparator is stored in the memory, and when a new signal is output from the phase comparator, the rotation speed of the motor is controlled based on this signal and the value stored in the memory. Therefore, even if the rotation changes due to aging of the motor, accurate rotation control can be performed by automatically updating the memory contents according to aging without resetting the memory value. You can Further, the subtractor subtracts the value of the memory from the output signal (phase error signal) of the phase comparator and outputs the subtraction result to the drive circuit, so that the speed control of the motor on the drive circuit side is easy. Become.

[Brief description of drawings]

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

FIG. 2 is a signal waveform diagram showing an operation of each unit of the apparatus of the above-described embodiment.

FIG. 3 is a block diagram showing a configuration of a conventional device.

FIG. 4 is a signal waveform diagram showing an operation of each unit of the conventional device.

[Explanation of symbols]

1 ... Motor, 2 ... Hall sensor, 3 ... Edge detection circuit,
4 ... Phase comparator, 5 ... Drive circuit, 6 ... Memory, 7 ... Selector, 8 ... Selection circuit, 9 ... Subtractor, 10 ... Weighting circuit.

Claims (4)

[Claims] 1. A motor rotation control device for controlling a motor rotation speed to be constant, wherein a rotation detector that outputs a plurality of detection signals at a predetermined cycle each time the motor makes one rotation, the detection signal and a reference. A phase comparator that compares the phase with the signal and outputs a phase error signal; and a memory that stores a value according to the phase error signal in advance,
A rotation control device for a motor, comprising: a drive circuit that controls a rotation speed of the motor based on an output signal of the phase comparator and a value stored in the memory. 2. A motor rotation control device for controlling the rotation speed of a motor to be constant, wherein a rotation detector that outputs a plurality of detection signals at a predetermined cycle each time the motor makes one rotation, and the plurality of detections. A phase comparator for comparing the phases of the signal and the reference signal to each one to output a plurality of phase error signals; a memory in which the value of the phase error signal is stored in advance for each of the plurality of detection signals; A rotation control device for a motor, comprising: a drive circuit that controls a rotation speed of the motor based on an output signal of the phase comparator and a value of the memory corresponding to the output signal. 3. A motor rotation control device for controlling a motor rotation speed to be constant, wherein a rotation detector that outputs a plurality of detection signals at a predetermined cycle every time the motor rotates once, and the detection signal and the reference. A phase comparator that compares the phase with a signal and outputs a phase error signal, a memory that is connected to the phase comparator and that stores the value of the output signal of this phase comparator, and a new output from the phase comparator A motor rotation control device comprising: a drive circuit that controls a rotation speed of the motor based on an output signal and a value stored in the memory. 4. The method according to claim 1, 2 or 3.
In the motor rotation control device described above, a subtractor that subtracts the value of the memory from the output signal of the phase comparator is provided in the preceding stage of the drive circuit, and the drive circuit is a motor according to the subtraction result of the subtractor. A rotation control device for a motor, which controls the rotation speed of the motor.