JP3361420B2 - Motor control circuit - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor control circuit, and more particularly to a motor control circuit that stabilizes phase pull-in in rotational phase control.

[0002]

2. Description of the Related Art In recent years, office automation equipment such as copiers and page printers.
As for equipment, colorization, definition, and digitization are progressing,
Accordingly, motors used in these devices are required to maintain high rotational speed accuracy in a wide rotational speed range and to be able to control rotational position.

A conventional motor control circuit will be described below.

FIG. 7 shows a block diagram of a first conventional motor control circuit. This motor control circuit generates an FG signal by converting a rotation signal output by the rotation detector 17 into a rectangular wave according to the rotation position of the motor F.
The G signal generation circuit 4, the speed control circuit 10 for comparing the FG signal and the reference speed signal by the comparator 11 and outputting the speed error signal, and the comparator 1 for the FG signal and the reference phase signal
3, a rotational speed control circuit 5 having a phase control circuit 12 for comparing and outputting a phase error signal, and control for synthesizing the speed error signal and the phase error signal (simple addition or weighted addition) to generate a drive control signal. The signal adjusting circuit 9 and the drive circuit 2 for controlling the rotation speed of the motor 1 according to the drive control signal from the control signal adjusting circuit 9 are provided.

The operation of the motor control circuit configured as described above will be described with reference to FIG. As for the control mode, control is performed in the "speed control mode" from the start-up, and at some point, the "speed control mode" is switched to the "speed & phase control mode" in which the "phase control mode" is added. The reference phase signal is given as a pulse corresponding to one cycle of the FG signal as shown in FIG. 8A, and its timing is FG.
It is given independently of the signal generation. (C) FG of FIG.
Signal 1 and (f) FG signal 2 each show an example of the timing of generation of the FG signal, and the phase error signals for these signals are rectangular waves of polarities and widths such as (d) and (g), respectively. It becomes a pulse. Further, (h) shows the rotation speed characteristic of the motor, and also shows the mode switching timing of the rotation speed characteristic at the time of starting.

First, the rotational speed characteristic by switching the control mode by the control signal adjusting circuit 9 will be described. As shown in FIG. 8, until the reference rotation speed at startup is reached, the speed error signal in the speed control mode causes
Control the motor 1. Next, after reaching the standard rotation speed,
The control signal adjusting circuit 9 synthesizes the speed error signal and the phase error signal by the rotation speed control into a drive control signal,
By controlling the drive of the motor, constant rotation speed control is possible.

Next, FIG. 9 shows a block diagram of a second conventional motor control circuit. This motor control circuit
An FG signal generation circuit 4 for generating an FG signal by converting a rotation signal output by the rotation detector 17 into a rectangular wave according to the rotation position of the motor 1, and a comparator 11 for comparing the FG signal and the reference speed signal. A rotation speed control circuit 5 having a speed control circuit 10 for comparing and outputting a speed error signal and a phase control circuit 12 for outputting a phase error signal by a comparator 13 to the FG signal and a reference phase signal, and the rotation detector 17 The rotational position detection circuit 3 for detecting the rotational position of the motor 1 from the rotational signal by the comparator 8 and the rotational position signal output from the rotational position detection circuit 3 and the reference position signal are compared by the comparator 8 to obtain a rotational position error signal. Drive control is performed by switching between a rotational position control circuit 7 for outputting the rotational position error signal and a speed control error signal obtained by combining the rotational position error signal with the speed error signal and the phase error signal. Control signal adjusting circuit 9 for outputting a No.
And a drive circuit 2 for controlling the rotation speed and the rotation position of the motor according to the drive control signal.

The operation of the motor control circuit configured as described above will be described with reference to FIG. First, "times when reaches the reference rotational speed by a control signal adjusting circuit 9
The rotation speed characteristic and the rotation position characteristic when switching to the " rolling speed control mode " will be described. (H) and (i) show the rotational speed characteristic and the rotational position characteristic.

As shown in the figure, since the motor 1 is controlled by the "rotational position control mode" based on the rotational position error signal until the reference rotational speed at the time of startup is reached, a constant time position can be secured. .

After the reference rotation speed is reached, constant rotation speed control is possible by controlling the motor in the "rotation speed control mode" by the speed control error signal obtained by combining the speed error signal and the phase error signal. And

[0011]

However, each of the conventional motor control circuits described above has the following problems.

Regarding the first conventional motor control circuit shown in FIG. 7, in the case of the PLL control circuit using the speed control circuit 10 and the phase control circuit 12 as the rotation speed control circuit 5, the phase control circuit 12 is particularly used. The relationship with the reference phase signal when detecting the phase error signal will be described with reference to FIG.

Since the reference phase signal is set in an arbitrary state as shown in (a), for example, when the FG signal 1 is generated at the timing of (c) or when the control mode is switched, the reference phase signal is already set. Despite reaching the rotation speed,
There is a problem in that the phase error signal 1 as shown in (d) is generated, the rotation is changed as shown by the rotation speed characteristic indicated by p in (h), and the motor control works at an unstable rotation speed.

Further, for example, at the timing of (f), F
When the G signal 2 is generated, when the control mode is switched,
Similar to the case of the FG signal 1, the phase error signal 2 as shown in (g) is generated even though the reference rotation speed has already been reached, and the rotation speed control characteristic shown by q in (h) appears. There is a problem that the motor control works at an unstable rotation speed due to the rotation fluctuation.

Next, in the second conventional motor control circuit shown in FIG. 9, especially in the case of a PLL control circuit using a speed control circuit 10 and a phase control circuit 12 as the rotation speed control circuit 5, especially phase control is performed. The relationship with the reference phase signal when the phase error signal is detected by the circuit 12 will be described with reference to FIG.

Since the reference phase signal is set in an arbitrary state as shown in (a), when the rotational position signal 1 and the FG signal 1 are generated at the timings of (b) and (c),
When the "rotational position control mode" is switched to the "rotational speed control mode", the reference rotational speed has already been reached, and the rotational position has also reached the reference rotational position.
The phase error signal 1 as described above is generated, and the motor rotates at an unstable rotation speed difference due to the rotation fluctuation as shown by the rotation speed control characteristic indicated by r in (h). Further, regarding the rotational position characteristic of (i), since the motor tries to cancel the positional error and stably keeps rotating at the constant rotational speed, the phase error occurs when the rotational position error occurs with respect to the reference rotational position. There was a problem that was locked.

When the rotational position signal 2 and the FG signal 2 are generated at the timings (e) and (f), when the "rotational position control mode" is changed to the "rotational speed control mode", the same as above. In spite of the fact that the reference rotation speed has already been reached and the rotation position has also reached the reference rotation position, the phase error signal 2 as shown in (g) is generated, and the rotation speed control indicated by s in (h) is performed. The motor rotates at an unstable rotation speed due to fluctuations in rotation as indicated by the characteristics.

Regarding the rotational position characteristic of (i),
Since the motor tries to cancel the phase error and keeps rotating stably at a constant rotation speed, there is a problem that the phase is locked when the rotation position error occurs with respect to the reference rotation position. there were.

It is an object of the present invention to solve the above problems, to provide a motor control circuit in which the phase error signal is stable and the rotation speed accuracy and the rotation position accuracy can be maintained in a wide rotation speed range.

[0020]

In order to achieve the above object, a motor control circuit according to a first aspect of the present invention includes a signal generating means for outputting a rotation signal according to a rotation position of a motor, and a rectangular wave for the rotation signal. An FG signal generation circuit for generating an FG signal by converting into an FG signal, the FG signal and a reference speed signal
The speed control that compares the
Control circuit, the FG signal and the reference phase signal by a comparator
And a phase control circuit for comparing and outputting a phase error signal,
Drive control signal by inputting the speed error signal and the phase error signal
And a control signal adjusting circuit for outputting the drive control signal.
And a drive circuit that controls the rotation speed of the motor.
The control signal adjustment circuit reaches the reference rotation speed at startup.
Until then, use the speed error signal as the drive control signal
After reaching the rotation speed, the speed error signal and the phase error
Is configured to combine with the difference signal into a drive control signal.
After the motor control circuit reaches the reference speed,
When the phase control circuit starts the control of the rotation phase of the motor, the first phase reference of the rotation phase is set to the time of the edge of the FG signal that should arrive immediately after the start of the rotation phase control of the motor. It is characterized in that it is provided with a phase reference setting means.

In the first aspect of the invention, the FG signal edge time that should arrive immediately after the start of the motor rotation phase control is the FG signal edge time immediately before the start of the motor rotation phase control. It is preferable to configure so as to set the time one reference cycle after the signal.

In order to achieve the above-mentioned object, the motor control circuit of the second invention of the present application detects from the signal generation means for outputting the rotation signal according to the rotation position of the motor and the rotation signal output by the signal generation means. A rotation position control circuit for controlling the rotation position of the motor by the rotation position signal, and an FG for generating the FG signal by converting the rotation signal into a rectangular wave.
Comparing the signal generation circuit with the FG signal and the reference speed signal
Speed control circuit that outputs speed error signal by comparing
And comparing the FG signal and the reference phase signal with a comparator
And a phase control circuit for outputting a phase error signal,
Position signal and reference position signal are compared by a comparator
A rotational position control circuit that outputs an error signal and the speed error
Signal, the phase error signal and the rotational position error signal
A control signal adjustment circuit that inputs and outputs a drive control signal, and
The drive that controls the rotation speed of the motor according to the drive control signal.
And a control circuit for starting the control signal.
Until the quasi-rotational speed is reached, the rotational position error signal is
As a drive control signal, after reaching the reference rotation speed, the above speed
Drive control signal by combining the error signal and the phase error signal
A motor control circuit configured to
After reaching the rotation speed, the phase control circuit turns the motor.
When starting the control of transposition phase, the first phase reference rotational phase of the motor, a phase reference setting means for setting the time of the edge of the FG signal to be arriving immediately after starting the rotational phase control of the motor It is characterized by that.

In the second aspect of the invention, the time of the edge of the FG signal that should arrive immediately after the start of the rotational phase control of the motor is calculated from the time of the edge of the FG signal that arrived immediately before the start of the rotational phase control of the motor. It is preferable to configure to set the time after one reference period of the FG signal,
Further, as the time, the rotational position control circuit outputs immediately before starting the rotational speed control from the time one reference period after the time of the edge of the FG signal that has arrived immediately before the rotational speed control circuit starts the rotational speed control of the motor. It is preferable to set the corrected time only for the time corresponding to the rotational position error.

[0024]

DETAILED DESCRIPTION OF THE INVENTION

(Embodiment 1) Hereinafter, Embodiment 1 of the present invention will be described with reference to the drawings.

The motor control circuit shown in FIG. 1 includes an FG signal generation circuit 4 for generating an FG signal by converting a rotation signal output from the rotation detector 17 into a rectangular wave according to the rotation position of the motor 1, A speed control circuit 10 for comparing the FG signal with a reference speed signal by a comparator 11 and outputting a speed error signal, and a phase control circuit for comparing the FG signal with a reference phase signal by a comparator 13 and outputting a phase error signal. A rotation speed control circuit 5 including a circuit 12, a control signal adjusting circuit 9 that synthesizes the speed error signal and the phase error signal to generate a drive control signal, and controls the rotation speed of the motor 1 according to the drive control signal. Drive circuit 2 for

The difference from the conventional configuration shown in FIGS. 7 and 8 is that the "speed control mode" is changed to the "speed & phase control mode".
In addition, when the control mode is switched, the phase reference setting circuit 20 that sets the reference phase signal based on the edge time of the FG signal output from the FG signal generation circuit 5 is provided.

The operation of the motor control circuit will be described with reference to FIG.

As shown in FIG. 2, since the phase reference setting circuit 20 sets the reference phase signal (d) with reference to the edge time of the FG signal (a) when shifting to the control mode, the FG signal and the reference phase signal are different from each other. Match. Now, when the speed is increased by performing control in the "speed control mode" from the time of startup, and when the reference rotation speed is reached at time T, the operation shifts to the "speed & phase control mode" to perform constant speed rotation. , The FG signal has a rectangular waveform with a substantially constant period as shown in FIG. Therefore, it can be predicted that the edge time of the FG signal which should arrive immediately after the control mode switching time T is approximately one reference period t after the FG signal from the edge time immediately before the time T. Therefore, as indicated by the broken line arrow in FIG.
The first phase reference signal P1 is generated at a time after one reference cycle t from the time point, and thereafter the phase reference signal P2, ... Is generated at every one reference cycle t, and speed control is performed using this. In addition, phase control is performed.

As a result, the "speed & phase control mode"
Since the edge time of the FG signal and the timing of the reference phase signal coincide with each other at the start of control by, the phase error does not occur and control instability does not occur. Therefore, thereafter, the phase control is performed according to this reference phase signal, and stable speed & phase control is performed as shown in (e) and (f) of FIG.

It should be noted that the first phase reference is always F which comes immediately after the time when the "speed & phase control mode" is entered.
The time is not limited to the G signal edge time, and a slightly later time (for example, 2 to 3 reference cycles later) may be used as the first phase reference.

(Second Embodiment) A second embodiment of the present invention will be described below with reference to the drawings.

The motor control circuit shown in FIG. 3 includes the FG signal generation circuit 4 for generating an FG signal by converting the rotation signal output from the rotation detector 17 into a rectangular wave according to the rotation position of the motor 1 and the FG signal generation circuit 4. The speed control circuit 10 for comparing the FG signal and the reference speed signal by the comparator 11 and outputting the speed error signal, and the phase control circuit 12 for comparing the FG signal and the reference phase signal by the comparator 13 and outputting the phase error signal. A rotation speed control circuit 5, a rotation position detection circuit 3 for detecting the rotation position of the motor 1 based on a rotation signal from the rotation detector 17, a rotation position signal output from the rotation position detection circuit 3 and a reference position. A rotational position control circuit 7 that outputs a rotational position error signal by a comparator 8 and the speed error signal, the phase error signal, and the rotational position error signal are switched. A control signal adjusting circuit 9, in response to the driving control signal from the control signal adjusting circuit 9, and a drive circuit 2 for controlling the rotational speed and rotational position of the motor 1.

The difference from the conventional configuration shown in FIGS. 9 and 10 is that the edge of the FG signal output from the FG signal generating circuit 5 when the "rotation position control mode" is changed to the "rotation speed control mode". The point is that the phase reference setting circuit 20 for setting the reference phase signal is provided based on the time.

The operation of the motor control circuit will be described with reference to FIGS. 4, 5 and 6.

FIG. 4 shows a case where the rotational speed and the rotational position match the reference value at the time of control switching. That is, since the rotational position error signal (c) is zero when the "rotational speed control mode" is entered, the edge of the FG signal (a) and the reference phase signal (d) match. In this case, the phase error signal of (e) can be stably output, and it is possible to shift to stable constant rotation operation as in the rotation speed characteristic of (f). , Again (g)
The rotational position error does not occur unlike the rotational position characteristic of.

FIG. 5 shows a case where the rotation speed and the rotation position have not reached the reference values at the time of control switching. In this case, the rotational position error signal (c) is corrected with reference to the edge time of the FG signal (a) when the "rotation speed control mode" is entered, and the reference phase signal is set as shown in (d). As a result, the phase error signal can be set to zero after correction as shown in (e), and it is possible to shift to a constant rotation operation as in the rotation speed characteristic of (f), and (g). The rotational position error is also canceled like the rotational position characteristic of, and it is possible to shift to the direction in which the rotational position error does not occur.

FIG. 6 shows the case where the rotational speed and the rotational position exceed the reference values at the time of control switching. In this case, the rotational position error signal (c) is corrected with reference to the edge time of the FG signal (a) when the "rotation speed control mode" is entered, and the reference phase signal is set as shown in (d). As a result, as shown in (e), the phase error signal can be made zero after correction, and it is possible to shift to a constant rotation operation as in the rotation speed characteristic of (f), and (g) It is possible to cancel the rotational position error and shift to the direction in which the rotational position error does not occur, as in the rotational position characteristic of).

As can be seen from FIG. 4, FIG. 5 and FIG. 6, by setting the reference phase signal (d) with reference to the reference position signal (b) at the time of mode transition, the rotational speed accuracy is wide. And, it is possible to enable optimum control that can maintain the rotational position accuracy.

[0039]

According to the first invention of the present application, when the "speed control mode" is changed to the "speed & phase control mode",
It enables stable speed control and secures rotation accuracy.

According to the second invention of the present application, when the "rotational position control mode" is changed to the "rotational speed control mode",
It enables stable speed control and secures rotation accuracy.
Further, regarding the rotational position at the time of starting and accelerating the motor, since the motor is controlled by the rotational position control circuit so that a rotational position error does not occur, an excellent motor control circuit that can secure a constant time fixed position is provided. realizable.

[Brief description of drawings]

FIG. 1 is a block diagram of a motor control circuit according to a first embodiment of the present invention.

FIG. 2 is a diagram for explaining the operation of the motor control circuit according to the first embodiment of the present invention.

FIG. 3 is a block diagram of a motor control circuit according to a second embodiment of the present invention.

FIG. 4 is a diagram for explaining the operation of the motor control circuit according to the second embodiment of the present invention.

FIG. 5 is a diagram for explaining the operation of the motor control circuit according to the second embodiment of the present invention.

FIG. 6 is an operation explanatory diagram of the motor control circuit according to the second embodiment of the present invention.

FIG. 7 is a block diagram of a conventional motor control circuit.

FIG. 8 is a control timing chart for explaining the operation of the motor control circuit.

FIG. 9 is a block diagram of another conventional motor control circuit.

FIG. 10 is a control timing chart for explaining the operation of the motor control circuit.

[Explanation of symbols]

1 motor 2 drive circuit 3 Rotation position detection circuit 4 FG signal generation circuit 5 Rotation speed control circuit 7 Rotational position control circuit 8, 11, 13 Comparison circuit 9 Control signal adjustment circuit 10 Speed control circuit 16 Position signal adjustment circuit 17 Rotation detector 20 Phase reference setting circuit

Continuation of front page (56) Reference JP-A-3-245788 (JP, A) JP-A-6-315290 (JP, A) JP-A-6-233573 (JP, A) (58) Fields investigated (Int .Cl. ⁷ , DB name) H02P 5/00

Claims (5)

(57) [Claims] 1. A signal generation means for outputting a rotation signal according to a rotation position of a motor, and an FG signal generation circuit for generating an FG signal by converting the rotation signal into a rectangular wave.
The FG signal and the reference speed signal are compared by a comparator.
A speed control circuit for outputting a speed error signal, and the FG signal
And the reference phase signal are compared by the comparator and the phase error signal is
Output phase control circuit, the speed error signal and the phase
Control signal adjustment to input error signal and output drive control signal
Circuit and the rotation speed of the motor according to the drive control signal
And a drive circuit for controlling, the control signal adjusting circuit,
The above-mentioned speed error until the reference rotation speed at startup is reached.
Use the signal as the drive control signal, and after reaching the reference rotation speed,
Driving by combining the speed error signal and the phase error signal
A motor control circuit configured to act as a control signal.
Then, when the phase control circuit starts controlling the rotation phase of the motor after reaching the reference rotation speed, the first phase reference of the rotation phase comes immediately after starting the rotation phase control of the motor. A motor control circuit comprising phase reference setting means for setting the time of the edge of the FG signal to be powered. Wherein as the time of the edge of the FG signal to be arriving immediately after starting the rotational phase control of the motor, the motor times
2. The motor control circuit according to claim 1, wherein the time point one reference cycle after the FG signal is set from the time point of the edge of the FG signal that has arrived immediately before the start of the phase inversion control . 3. A signal generation means for outputting a rotation signal according to the rotation position of the motor, and a rotation position control circuit for controlling the rotation position of the motor by the rotation position signal detected from the rotation signal output by the signal generation means. , FG signal generation that generates an FG signal by converting the rotation signal into a rectangular wave
The raw circuit, the FG signal and the reference speed signal are compared by a comparator.
And a speed control circuit that outputs a speed error signal by comparing
The FG signal and the reference phase signal are compared by a comparator and the phase is
A phase control circuit that outputs an error signal, and the rotational position signal
And the reference position signal are compared by a comparator and the rotational position error signal is
Position control circuit for outputting a signal, the speed error signal,
Input the phase error signal and the rotational position error signal
A control signal adjusting circuit for outputting a drive control signal;
Drive circuit that controls the rotation speed of the motor according to the control signal
With the door, the control signal conditioning circuit, the reference rotation during startup
Drive the rotational position error signal until the speed is reached.
As a control signal, after reaching the standard rotation speed, the speed error signal
Signal and the phase error signal are combined into a drive control signal.
Is a motor control circuit configured as
After the phase is reached, the phase control circuit
The phase reference setting means for setting the first phase reference of the rotation phase of the motor at the time of the edge of the FG signal that should arrive immediately after the start of the rotation phase control of the motor. Motor control circuit characterized by. As time edge of the FG signal to be arriving immediately after starting the 4. A motor rotation phase control, the motor times
4. The motor control circuit according to claim 3, wherein the time after one reference period of the FG signal is set from the time of the edge of the FG signal that has arrived immediately before the start of the phase inversion control . 5. The speed control time is set as the time of the edge of the FG signal that should arrive immediately after starting the rotation phase control of the motor.
The road arrived just before the start of motor speed control F
From the time one reference period after the time of the edge of the G signal,
The motor control circuit according to claim 4, wherein the motor control circuit is configured to set the corrected time only for the time corresponding to the rotational position error output by the rotational position control circuit immediately before starting the rotational speed control.