JP2001231297A - Equipment and method for controlling stepping motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a controller of a stepping motor which can increase rotor stop positions at any place without depending on a microstep method. SOLUTION: In driving the stepping motor by a 1-2 phase excitation method, in a two phase excitation block wherein a B+ phase excitation signal and an A- phase excitation signal are outputted from a motor driver in correspondence with a B+ phase driving signal and an A- phase driving signal outputted from a CPU, an A phase control signal CTL1 is outputted from the CPU together with the B+ phase driving signal and A-phase driving signal to set the voltage level of the A- phase excitation signal to 1/2, and an excitation position 2-3 wherein the position of electrodes of a rotor is controlled to 1/4 from the B+ side between a B+ phase and the A- phase is newly installed. Without executing a multistage control using an IC for a special purpose by the conventional microstep method, a new excitation position can be installed at any place between excitation positions 0-1, 1-2, 2-3, 3-4,..., 7-0 to increase necessary rotor stop positions.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a control device and a control method for a stepping motor.

[0002]

2. Description of the Related Art Generally, a stepping motor is an FDD, HDD, HDD, or the like that can precisely control the number of rotations and the position without detecting the rotation or the rotation position.
It is widely used as an actuator for positioning control of various devices and devices, including information devices such as cameras, office devices such as copiers and word processors.

A typical rotation control system of such a stepping motor includes a one-phase excitation system, a two-phase excitation system, and a 1-2-phase excitation system.

[0004] In the one-phase excitation system, a plurality of motor coils arranged at equal intervals around a rotor made of permanent magnets are sequentially driven for excitation in each phase, so that the rotor pole is located at the excitation phase. It is drawn in order and rotates stepwise. In this case, the number of rotation steps is the same as the number of motor coils. For example, in the case of a four-phase stepping motor, the rotor rotates by 90 degrees in four steps. Makes one rotation.

In the two-phase excitation method, a plurality of motor coils arranged around the rotor are sequentially driven by excitation in two adjacent phases, whereby the poles of the rotor are sequentially drawn to the middle of each excitation phase. In this case as well, the number of rotation steps is the same as the number of motor coils. For example, in the case of a four-phase stepping motor, the rotor rotates by 90 degrees and makes one rotation in four steps. Becomes

FIG. 5 is a timing chart showing a 1-2-phase excitation signal for a 4-phase stepping motor.

FIG. 6 shows a four-phase type stepping motor having a 1-2 position.
FIG. 4 is a diagram illustrating a rotor rotation state at each excitation timing when rotation control is performed by a phase excitation method.

That is, the excitation numbers 0 to 7 in FIG.
As shown in FIG. 6A to FIG.
1 phase excitation → 2 phase excitation of A phase B phase → 1 phase excitation of B phase →
By sequentially repeating the one-phase excitation and the two-phase excitation for the adjacent motor coils in the order of B-phase A-phase two-phase excitation → A-phase one-phase excitation →, the rotor poles become the positions of the respective excitation phases. It is sequentially drawn toward the intermediate position of the next excitation phase and rotates stepwise. In this case, the number of rotation steps is twice the number of motor coils, and the rotor rotates by 45 degrees in eight steps. One rotation.

[0009]

As described above, when the rotation of the stepping motor is controlled by the one-phase excitation method or the two-phase excitation method, the rotor stop position of the four excitation positions is obtained, and the 1-2 phase rotation position is obtained. When the rotation is controlled by the excitation method, a rotor stop position of eight excitation positions can be obtained.
In order to perform finer positioning control, there is a problem that the number of rotor stop positions is small in the four excitation positions and the eight excitation positions.

[0010] Therefore, by controlling the rise and fall of the excitation signal in multiple stages between the excitation positions in the 1-2 phase excitation method, the excitation position is subdivided and the rotor stop position is increased. A micro-step type rotation control technology has been considered.

However, since the rotation control of the stepping motor by the micro step method is performed by using a dedicated IC, there is a problem that the cost is increased. In addition, the micro step method using the dedicated IC requires a rotor. In order to rotate to the target position, all the motor excitations at the predetermined excitation positions set in multiple stages must be performed during that time, and although many stop positions can be obtained, the control speed becomes slow. There is.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and provides a control device and a control method for a stepping motor that can increase a rotor stop position at an arbitrary position without using a microstep method. The purpose is to provide.

[0013]

According to a first aspect of the present invention, there is provided a stepping motor control apparatus comprising: an exciting step based on a predetermined exciting method including at least two-phase exciting timing for each exciting phase of the stepping motor; Excitation signal supply means for supplying a signal;
Control signal output means for outputting a control signal for one of the two-phase excitations at an arbitrary timing for supplying an excitation signal for phase excitation; and control for one excitation phase by the control signal output means. When a signal is output, the signal level of the excitation signal supplied to the one excitation phase by the excitation signal supply means is preset to be lower than the signal level of the excitation signal supplied to the other excitation phase. Excitation signal adjusting means for adjusting and setting the signal level to the adjusted signal level.

In the control apparatus for a stepping motor according to the first aspect of the invention, the two-phase excitation signal is supplied to each excitation phase of the stepping motor at an arbitrary timing based on a predetermined excitation method. A control signal for any one of the excitation phases is output, and when this control signal is output, the signal level of the excitation signal supplied to the one excitation phase is changed to the other excitation phase. On the other hand, since the signal level is adjusted and set to a preset signal level lower than the signal level of the supplied excitation signal, the excitation target 2
A new rotor stop position closer to the other excitation phase side than one excitation phase middle is obtained.

According to a second aspect of the present invention, there is provided a stepping motor control device, comprising: excitation signal supply means for supplying an excitation signal based on a two-phase excitation method to each excitation phase of the stepping motor; Signal waveform converting means for changing a signal level of each excitation signal supplied to each excitation phase of the stepping motor based on a two-phase excitation method in a sinusoidal manner by a supply means.

In the control device for a stepping motor according to the second aspect, when an excitation signal based on the two-phase excitation method is supplied to each excitation phase of the stepping motor, the control is performed based on the two-phase excitation method. Since the signal level of each supplied excitation signal is changed in a sinusoidal manner, the transition of the excitation force between adjacent excitation phases is linear, and the rotation of the rotor can be controlled steplessly.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) FIG. 1 is a diagram showing a configuration of a stepping motor control device according to a first embodiment of the present invention.

In FIG. 1, reference numeral 10 denotes a stepping motor (M). In this embodiment, the stepping motor 10 has, for example, A + phase and A-phase motor coils disposed at opposite poles, and a B + phase in the orthogonal direction. And a B-phase motor coil at the opposite pole.

The stepping motor 10 is controlled in rotation by a 1-2-phase excitation signal supplied from a driver IC 11, and A + and A- phase excitation signals are generated and supplied by a motor driver 12a, and B + Phase and B-
The phase excitation signal is generated and supplied by the motor driver 12b.

The A + phase and A- phase excitation signals and the B + phase and B- phase excitation signals generated by the respective motor drivers 12a and 12b of the driver IC 11 are transmitted to a CPU (control unit) 1.
A-phase drive signal 13a and B-phase drive signal 1
3b and an A-phase control signal CTL1 and a B-phase control signal CTL, which are generated in accordance with the A-phase control signal CTL1 and the B-phase control signal CTL2.
2 is adjusted to a preset control voltage via the voltage setting circuits 14a and 14b and supplied to the corresponding motor drivers 12a and 12b.

The CPU (control unit) 13 includes an A-phase drive signal 13a and a B-phase drive signal 13b based on a 1-2-phase excitation system.
And the A-phase control signal CTL1 and the B-phase control signal CTL2 are converted into drive signals A +, A-, B +, B- and control signals CT corresponding to the control position.
L1 and CTL2 are combined and output.

Each motor driver 12 of the driver IC 11
The A + phase and A- phase excitation signals and the B + phase and B- phase excitation signals generated and output by the
(Control unit) A-phase drive signals 13a and B output from 13
The phase drive signal 13b is similarly changed and output at a timing corresponding to the change.

On the other hand, A + generated and output by each motor driver 12a, 12b of the driver IC 11
The signal (excitation voltage) levels of the phase and A-phase excitation signals and the B + and B-phase excitation signals are determined by the CPU (control unit).
13 and the A-phase control signals CTL1 and B
Each voltage setting circuit 14 is controlled by the phase control signal CTL2.
a, 14b via the motor drivers 12a, 12b
Is adjusted according to the control voltage supplied to the A-phase control signal CTL.
The control voltage supplied to the motor drivers 12a and 12b is set to a high level in a state where the 1, 1-phase control signal CTL2 is not output, and in a state where the A-phase control signal CTL1 and the B-phase control signal CTL2 are output. The control voltage supplied to the motor drivers 12a and 12b is set to a low level.

Then, an A-phase control signal CTL1 and a B-phase control signal CTL are sent from the CPU (control unit) 13.
When the high-level control voltage that does not output the signal No. 2 is supplied, the A + -phase and A--phase excitation signals generated from the motor drivers 12a and 12b and the B + -phase and B-phase
The signal (excitation voltage) level of the phase excitation signal is adjusted and set to the maximum level, and the A-phase control signal CTL1
Or when a low-level control voltage at which the B-phase control signal CTL2 is output is supplied,
A + generated and output from the motor drivers 12a and 12b
The signal (excitation voltage) levels of the phase and A-phase excitation signals and the B + and B-phase excitation signals are adjusted and set to half the maximum level.

When the voltage level of the excitation signal for a certain motor coil of the stepping motor 10 is reduced to half, the force for pulling the rotor pole by the motor coil is also reduced to one half. For example, the motor drivers 12a and 12b When the excitation signal is supplied to the A + phase and the B + phase from, when the voltage level of the A + phase excitation signal is set to half by the A-phase control signal CTL1,
The rotor pole is stopped at a position which is closer to the B + phase side by half than the intermediate position between the A + phase and the B + phase (three-quarter position between the A + phase and the B + phase). During the two-phase excitation, B +
When the voltage level of the phase excitation signal is set to one half, the rotor poles are more A than the middle position between the A + phase and the B + phase.
+ Phase side halfway between them (A + Phase-B
+ (1/4 position between phases).

That is, in the rotation control sequence of the stepping motor 10 based on the 1-2-phase excitation system, the output of the A-phase control signal CTL1 or the B-phase control signal CTL2 during the two-phase excitation period causes the A-phase excitation signal or the B-phase excitation signal to be output. By increasing the excitation timing at which the voltage level of the excitation signal is set to one half, the rotor stop position can be increased to one quarter or three quarters between adjacent excitation phases.

FIG. 2 shows the control sequence of the A and B phase drive signals 13a and 13b and their control signals CTL1 and CTL2 output from the CPU (control section) 13 of the stepping motor control device in the 1-2 phase excitation mode. A output from the motor drivers 12a and 12b according to
6 is a timing chart showing a change in a B-phase excitation signal.

In the stepping motor control device of the first embodiment, the A-phase drive signal 13a and the B-phase drive signal 13b of the 1-2-phase excitation system in which the rotor stop position of 8 steps can be obtained in the excitation positions of 0 to 7 Exciting position 2 in which the B + phase is excited by one phase and the rotor pole is stopped at the B + phase position, and the A + phase adjacent to the B + phase is excited by two phases so that the rotor pole is located in the middle. With the excitation position 3 to be stopped, an A-phase control signal CTL1 is
+ Phase and A- phase are excited in two phases and the rotor poles are
Excitation position 2 to stop at 1/4 position from phase side
-3 is added.

That is, when the control position of the stepping motor 10 is set to the excitation position 2-3, the 1-2-phase drive signal output from the CPU (control unit) 13 accompanies the output of the A-phase control signal CTL1. B + drive signal and A
A two-phase drive signal with the drive signal. In response to this, a half-level A-excitation signal is output from the motor driver 12a to the A-phase of the stepping motor 10, and a predetermined level of the A-excitation signal is output from the motor driver 12b. Since the B + excitation signal is output to the B + phase of the stepping motor 10, the pole of the rotor of the stepping motor 10 is positioned at one-quarter (22.5 degrees) from the B + phase between the B + phase and the A- phase. Stop control is performed.

Therefore, according to the stepping motor control device of the first embodiment having the above-described configuration, when the stepping motor 10 is driven by the 1-2 phase excitation method, for example, the B + phase driving from the CPU (control unit) 13 is performed. Motor drivers 12a, 12a according to the signals and the A-phase drive signals.
b outputs a B + phase excitation signal and an A− phase excitation signal
In the phase excitation section, the A-phase control signal CTL1
And the voltage level of the A-phase excitation signal is set to half, and the voltage of the rotor electrode is changed to B + between the B + phase and the A-phase.
Since a new excitation position 2-3 controlled to a quarter position from the side is provided, the multi-step control of the 1-2-phase excitation signal using the conventional microstep-type dedicated IC is not performed. However, in the case of a four-phase motor, there are eight steps between the excitation positions 0 to 7, which are 8 steps, between adjacent excitation positions 0-1, 1-2, 2-3, 3-4,.
A new excitation position can be provided at an arbitrary position of −0 to increase the required rotor stop position.

In the first embodiment, the CPU (control unit) 13 sends an A-phase or B-phase control signal CTL.
1 and CTL2, the motor driver 12
By setting the voltage level of the A-phase excitation signal or B-phase excitation signal output from a and 12b to one half, the stop position of the rotor pole obtained in the two-phase excitation state can be set between the A-phase and the B-phase. Is increased at the third quarter position or the quarter position. However, when the control signals CTL1 and CTL2 are output, the A-phase excitation signal or the B-phase excitation signal from the motor drivers 12a and 12b is output. The voltage decay level is
The stop position of the pole of the rotor is shifted to the B phase between the A phase and the B phase or A
What is necessary is just to set arbitrarily in advance according to which position in the vicinity is added.

Further, in the first embodiment, the A-phase or B-phase control signals CTL1 and CTL2 are output at an arbitrary timing during the two-phase excitation period of the stepping motor 10 in the 1-2-phase excitation method. Although a new excitation position is provided in which the voltage level of the A-phase excitation signal or the B-phase excitation signal from the drivers 12a and 12b is attenuated, the two-phase excitation method is used as described in the second embodiment. A + phase, B + phase → B +
Excitation signals to be sequentially supplied between the phase, A-phase → A-phase, B-phase → B− phase, A + phase are controlled by the CPU (control unit) 13 instead of the rectangular excitation signals. By adjusting the output of the signals CTL1 and CTL2 so as to be a sine-wave-like excitation signal, the stop position of the pole of the rotor is set to be infinite, and the A at arbitrary timing is set.
The rotor stop position may be provided at a desired position by storing and reproducing the phase and B phase drive signals 13a and 13b and the A and B phase control signals CTL1 and CTL2.

(Second Embodiment) FIG. 3 is a diagram showing a configuration of a stepping motor control device according to a second embodiment of the present invention.

FIG. 4 shows the control sequence of the A and B phase drive signals 13a and 13b and their control signals CTL1 and CTL2 output from the CPU (control section) 13 of the stepping motor control device in a two-phase excitation mode and the corresponding control sequences. A, B output from the motor drivers 12a, 12b
6 is a timing chart showing a change in a phase excitation signal.

In the stepping motor control device according to the second embodiment, the CPU (control unit) 13 outputs A
The phase and B phase drive signals 13a and 13b are output based on a two-phase excitation method. Also, the A-phase and B-phase control signals CTL1 and CTL2 output from the CPU (control unit) 13 are pulse width signals corresponding to the periods of the A-phase and B-phase drive signals 13a and 13b, and are used as low-pass filters (L .PF
1) The above A phase through 15a and (LPF2) 15b
The signals are supplied to the motor drivers 12a and 12b as sinusoidal signals that coincide with the rising / falling signal periods of the B-phase drive signals 13a and 13b.

The motor drivers 12a and 12a
b, the sine-wave A-phase control signal CTL1 that matches the signal cycle of the A-phase drive signal 13a and the sine-wave B-phase control signal CTL2 that matches the signal cycle of the B-phase drive signal 13b. 1
The two-phase excitation signals generated and output in 2a and 12b are:
It is configured to be output in a sinusoidal manner.

That is, the A-phase and B-phase drive signals 13a and 13b output from the CPU (control unit) 13 are drive signals based on the two-phase excitation method.

When no control signal is supplied from the CPU 13 to the motor drivers 12a and 12b, the A-phase and B-phase drive signals 13a and 13b
Are generated and output to the respective excitation phases of the stepping motor 10, so that the stop position of the pole of the rotor is set between the adjacent excitation phases A
+, B +, B +, A-, A-, B-, B-, A +
4 steps (0, 1, 2, 2) corresponding to the positions between
3).

On the other hand, A-phase and B-phase based on the two-phase excitation method
The A-phase drive signal 1 together with the phase drive signals 13a and 13b
A sine-wave A-phase control signal CTL1 having a cycle matching the signal cycle of 3a and a sine-wave B-phase control signal CTL2 having a cycle matching the signal cycle of the B-phase drive signal 13a are supplied to the motor drivers 12a and 12b. In this case, the A-phase excitation signal and the B-phase excitation signal output from the motor drivers 12a and 12b respectively have a sinusoidal waveform in accordance with the signal change of the sinusoidal A-phase control signal CTL1 and B-phase control signal CTL2. , The rotor poles are A + phase, B
The position "0" where the voltage level of the excitation signal balances between the + phases, the position "1" where the voltage level of the excitation signal balances between the B + and A- phases, and the voltage level of the excitation signal between the A- and B- phases The rotation is linearly and steplessly controlled between the position "2" where the voltage level of the excitation signal balances between the position "2" and the B- and A + phases.

In the case of the stepping motor control device according to the second embodiment, the A-phase and B-phase drive signals 13 at the timing corresponding to the desired rotor rotational position are used.
a, 13b and A-phase and B-phase control signals CTL1,
By storing the combination of CTL2s by the CPU 13 and performing reproduction control, the combination is not limited to four-step or eight-step stepwise rotation stop control obtained by a simple two-phase excitation method or a one-two-phase excitation method. An arbitrary number of rotation stop controls can be performed at the excitation position.

Therefore, according to the stepping motor control device of the second embodiment having the above configuration, the CPU 13
The A + phase and A- phase based on the two-phase excitation method are provided for the phase driving motor driver 12a and the B phase driving motor driver 12b.
A phase drive signal 13a and a B + phase and B- phase drive signal 13b are supplied, and a sinusoidal A-phase control signal CTL1 that changes in the same cycle as the drive signals 13a and 13b.
And the B-phase control signal CTL2, and the A + phase, which changes according to the signal change of the sine-wave A-phase control signal CTL1 and the B-phase control signal CTL2,
Since the A-phase excitation signal and the B + phase and B-phase excitation signals are generated and output, the rotation of the rotor can be controlled in a stepless manner. Can be obtained.

[0043]

As described above, according to the control apparatus for a stepping motor according to the first aspect of the present invention, an excitation signal of two-phase excitation is supplied to each excitation phase of the stepping motor based on a predetermined excitation method. At an arbitrary timing, a control signal for one of the two-phase excitations is output, and when this control signal is output, the excitation signal supplied to the one excitation phase is output. The signal level is adjusted and set to a preset signal level lower than the signal level of the excitation signal supplied to the other excitation phase, so that the other excitation phase side is located between the middle of the two excitation phases to be excited. The shifted rotor stop position can be newly obtained.

According to the control apparatus for a stepping motor according to the second aspect of the present invention, when an excitation signal based on a two-phase excitation method is supplied to each excitation phase of the stepping motor, the two-phase excitation signal is supplied. Since the signal level of each excitation signal supplied based on the excitation method is changed in a sinusoidal manner,
The transition of the exciting force between adjacent exciting phases becomes linear, and the rotation of the rotor can be controlled steplessly.

Therefore, the rotor stop position can be increased at an arbitrary position without using the conventional micro step method.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a stepping motor control device according to a first embodiment of the present invention.

FIG. 2 shows A- and B-phase drive signals output from a CPU (control unit) of the stepping motor control device of the first embodiment in a 1-2-phase excitation mode, and a control signal CTL thereof;
1 is a timing chart showing a control sequence of CTL2 and a change in A and B phase excitation signals output from a motor driver in accordance with the control sequence.

FIG. 3 is a diagram showing a configuration of a stepping motor control device according to a second embodiment of the present invention.

FIG. 4 shows A- and B-phase drive signals output from a CPU (control unit) of the stepping motor control device of the second embodiment in a two-phase excitation mode, and control signals CTL1,
6 is a timing chart showing a control sequence of CTL2 and a change in A-phase and B-phase excitation signals output from the motor driver in response to the control sequence.

FIG. 5 is a timing chart showing a 1-2-phase excitation signal for a 4-phase stepping motor.

FIG. 6 is a diagram illustrating a rotor rotation state at each excitation timing when the rotation of a four-phase stepping motor is controlled by a 1-2-phase excitation method.

[Explanation of symbols]

 Reference Signs List 10 ... 4-phase stepping motor (M) 11 ... Driver IC 12a ... A-phase motor driver 12b ... B-phase motor driver 13 ... CPU (control unit) 13a ... A-phase drive signal 13b ... B-phase drive signal CTL1 ... A Phase control signal CTL2 ... B-phase control signal 14a ... A-phase control signal voltage setting circuit 14b ... B-phase control signal voltage setting circuit 15a ... L. P. F1 15b L.B. for B-phase control signal P. F2

Claims (4)

[Claims] 1. An excitation signal supply means for supplying an excitation signal based on a predetermined excitation method including at least two-phase excitation timing to each excitation phase of a stepping motor, and two-phase excitation excitation by the excitation signal supply means. Control signal output means for outputting a control signal for any one of the two-phase excitations at an arbitrary timing for supplying a signal; and a control signal for one of the excitation phases is output by the control signal output means. In this case, the signal level of the excitation signal supplied to the one excitation phase by the excitation signal supply means is set to a predetermined signal level lower than the signal level of the excitation signal supplied to the other excitation phase. A stepping motor control device, comprising: an excitation signal adjusting means for adjusting and setting the stepping motor. 2. For each excitation phase of a stepping motor,
Excitation signal supply means for supplying an excitation signal based on the two-phase excitation method; and a signal level of each excitation signal supplied based on the two-phase excitation method for each excitation phase of the stepping motor by the excitation signal supply means. A control device for a stepping motor, comprising: a signal waveform conversion unit that changes the waveform into a sine wave. 3. An excitation signal supply procedure for supplying an excitation signal based on a predetermined excitation method including at least two-phase excitation timing to each excitation phase of the stepping motor, and the two-phase excitation is excited by the excitation signal supply procedure. At an arbitrary timing for supplying a signal, a control signal output procedure for outputting a control signal for any one of the two-phase excitations, and a control signal for one excitation phase is output by the control signal output procedure. In this case, the signal level of the excitation signal supplied to the one excitation phase by the excitation signal supply procedure is set to a predetermined signal level lower than the signal level of the excitation signal supplied to the other excitation phase. And a step of adjusting the excitation signal. 4. For each excitation phase of a stepping motor,
An excitation signal supply procedure for supplying an excitation signal based on the two-phase excitation method, and a signal level of each excitation signal supplied based on the two-phase excitation method for each excitation phase of the stepping motor by the excitation signal supply procedure. A step of controlling a stepping motor, comprising: a step of converting a signal waveform into a sinusoidal waveform.