JP2001245494A - Device and method for controlling stepping motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce an amount of power consumption accompanying the stop control of a motor and suppress the heating an excitation phase in the controller of a stepping motor. SOLUTION: In the case that each excitation phase is fixed by the two-phase excitation timing of an A phase and a B phase on rotation control on the basis of the 1-2 phase excitation system of the stepping motor and rotation stop control is performed, each control signal CTL1, CTL2 of the A phase and the B phase corresponding to the fixing excitation phase is output together in a stop holding period necessary for the fixing and holding of a rotor at the stop position after a stop fixing period until the damping vibration of the rotor is converged, thereby the excitation voltage level of an excitation signal continuously driving the fixing excitation phase is regulated and set at a half. Thereby the power consumption amount accompanying the stop holding of the rotor can be reduced, and the consumption of a battery power source can be suppressed. In addition, the heating of the fixing excitation phase can be suppressed.

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

FIG. 5 shows a four-phase stepping motor 1-2.
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. 5A 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.

In such a stepping motor whose rotation is controlled by various excitation methods, when the rotation operation is stopped, an excitation drive signal at an excitation timing when the rotor is rotated to a target position is transmitted by the rotor. Although it is continuously supplied for a certain period of time until the excitation is stably fixed at the stop position, the voltage level of the excitation drive signal is the same as the excitation voltage level during the normal rotation control. Supplied.

When such a stepping motor is used in a portable device such as a camera, a battery power source such as a battery or a rechargeable battery is used as the driving power source.

[0011]

However, in the conventional rotation stop control for the stepping motor, the voltage level of the excitation drive signal accompanying the stop control remains at the same excitation voltage level as in the normal rotation control. Is supplied continuously for a certain period of time necessary for complete stoppage of the rotor. For example, when stop control is frequently performed as a stepping motor for adjusting the lens and aperture of a camera, the power accompanying this In addition to the problem of large consumption, there is a problem that the excited phase that is continuously energized generates heat at a high temperature.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and has a stepping motor control device and a control device capable of reducing power consumption accompanying motor stop control and suppressing heat generation in an excitation phase. It is an object to provide a control method.

[0013]

According to a first aspect of the present invention, there is provided a stepping motor control device for supplying an excitation signal based on a predetermined excitation method to each excitation phase of the stepping motor. Excitation voltage setting means for setting the voltage level of the excitation signal supplied to each excitation phase of the stepping motor by the excitation signal supply means to one of a first voltage level and a second voltage level lower than the first voltage level. The voltage level of the excitation signal set by the excitation voltage setting means is set to the first voltage level during the motor rotation control, and the second voltage level is set during the motor stop control.
And setting control means for setting the voltage level to

In the control apparatus for a stepping motor according to the first aspect, when the motor rotation is controlled, each excitation phase based on a predetermined excitation method is determined by an excitation signal of a first voltage level which is a normal excitation voltage level. Is driven to control the rotation. At the time of motor stop control, the excitation phase of the stop target is driven by the excitation signal of the second voltage level lower than the normal excitation voltage level, and the stop control is performed. The power consumption can be reduced.

According to a second aspect of the present invention, there is provided a stepping motor control apparatus according to the first aspect, wherein the motor stop control includes a first stepping motor for a stop target excitation phase. And a stop holding period after the fixed supply period of the excitation signal at the voltage level.

In the control apparatus for a stepping motor according to the second aspect of the present invention, the normal excitation is performed during the stop holding period after the fixed supply period of the excitation signal at the first voltage level with respect to the stop target excitation phase by the motor rotation control. Since the stop target excitation phase is continuously driven and stopped and held by the excitation signal of the second voltage level lower than the voltage level, even if the required stop holding period is long, it is possible to suppress the power consumption associated therewith.

[0017]

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

FIG. 1 is a diagram showing a configuration of a stepping motor control device according to an 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 a combination of the A-phase control signal CTL1 and the B-phase control signal CTL2. The A-phase control signal CTL1 and the B-phase control signal CTL2 are both voltage setting circuits 14a and 14b.
, The control voltage is adjusted to a preset control voltage and supplied to the corresponding motor drivers 12a and 12b.

The drive voltage of each part in the stepping motor control device is supplied from a battery power supply 15.

The CPU (control unit) 13 includes an A-phase drive signal 13a and a B-phase drive signal 13b based on the 1-2-phase excitation method.
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
In the present embodiment, when the CPU 13 does not output the A-phase control signal CTL1 and the B-phase control signal CTL2, the voltage setting circuits 14a and 14b transmit the motor drivers 12a and 12a. The control voltage supplied to 12b is set to a high level, and the CPU 13 outputs the A-phase control signal CTL1 and the B-phase control signal CTL.
In the state where 2 is output, the control voltage supplied from the voltage setting circuits 14a and 14b 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.
2 is not output, and a high-level control voltage is applied from the voltage setting circuits 14a and 14b to the motor driver 12.
a, the signal (excitation voltage) of the A + phase, A- phase excitation signal and the B + phase, B- phase excitation signal generated and output from the motor drivers 12a, 12b is at the maximum level. After the adjustment, the A-phase control signal CTL1 and the B-phase control signal CTL2 are output, and the low-level control voltage is supplied from the voltage setting circuits 14a, 14b to the motor drivers 12a, 12b.
Is supplied to the motor driver 12a,
A + phase and A− phase excitation signals generated and output from
The signal (excitation voltage) level of the + phase and B-phase excitation signals is adjusted and set to a half of the maximum level.

For example, at one-phase excitation timing of the A + phase accompanying the 1-2-phase excitation control of the stepping motor 10,
When the A + phase excitation signal is generated and output from the A phase motor driver 12a by the A + phase drive signal 13a from the CPU (control unit) 13, the voltage setting circuit 14a is output from the voltage setting circuit 14a by the output of the A phase control signal CTL1.
When the control voltage supplied to the motor driver 2a becomes low level, the excitation voltage level of the A + phase excitation signal generated and output from the motor driver 12a is set to half the voltage level in the normal rotation control. At the two-phase excitation timing of A + phase and B + phase accompanying the 1-2-phase excitation control, the A + phase drive signal 1 from the CPU (control unit) 13 is output.
When the A + phase excitation signal and the B + phase excitation signal are generated and output from the A-phase and B-phase motor drivers 12a and 12b respectively by the 3a and B + drive signals 13b, the A-phase control signal CTL1 and the B-phase control signal CTL2 are generated. When each control voltage supplied from the voltage setting circuits 14a and 14b to the motor drivers 12a and 12b becomes low level by the output, the motor driver 1
A + phase excitation signal generated and output from 2a, 12b, B +
The excitation voltage level of each of the phase excitation signals is set to a voltage level that is half that of the normal rotation control.

That is, in this stepping motor control device, when the excitation phase corresponding to the target stop position of the rotor is driven with the stop control of the stepping motor 10, the A-phase control signal CTL1
And the output of the B-phase control signal CTL2, the excitation voltage level for driving the excitation phase of the stop target is reduced by half.
The power consumption at the time of stopping the motor is reduced.

At this time, during the period from the time of the excitation driving to the stop target excitation phase to the time when the damped vibration of the rotor converges (the stop fixed period), the control signals CTL1 and CTL are set.
By driving the stop target excitation phase with the excitation signal having the same maximum excitation voltage level as that of the previous rotation control period without outputting the signal 2, the rotor damping vibration at the target stop position is quickly converged.

After the rotor stops at the target stop position (after the fixed stop period elapses), during a period in which the rotor needs to be fixedly held at the stop position (stop holding period), the side corresponding to the excitation phase being driven is stopped. Control signals CTL1, CTL
2 is output, and the excitation phase is continuously driven by an excitation signal having an excitation voltage level that is half of that before, so that the rotor can be kept completely stationary at the target stop position.

At this time, since the excitation voltage level of the excitation signal is adjusted and set to one half of that in the normal rotation control, the power consumption accompanying the motor stop holding can be reduced, and the heat generation of the corresponding excitation phase is suppressed. become able to.

After the rotor is held stationary at the target stop position (after the stop holding period has elapsed), the drive signals 13a and 13b and the control signal CTL that have been output up to that time are output.
By stopping all outputs of CTL1 and CTL2, supply of the excitation signal to the stop target excitation phase is also stopped, and demagnetization is achieved.

FIG. 2 shows A- and B-phase drive signals 13a and 13b associated with the stop control at the one-phase excitation position output from the CPU (control unit) 13 of the stepping motor control device in the 1-2-phase excitation mode, and their signals. Control signal CTL
1 is a timing chart showing a control sequence of CTL1 and CTL2 and changes in A and B phase excitation signals output from motor drivers 12a and 12b in response to the control sequence.

In the stepping motor control device of the present embodiment, the A-phase drive signal 13a and the B-phase drive signal 13b of the 1-2-phase excitation system in which an 8-step rotor stop position can be obtained at the excitation positions of 0 to 7 are obtained. (See FIG. 4),
First, as shown in FIG. 2, a case will be described in which the rotor stop control is performed at the timing of one-phase excitation of the A-phase corresponding to the excitation position 4.

That is, A from the CPU (control unit) 13
The phase drive signal 13a and the B-phase drive signal 13b are fixed in the output state of one-phase excitation with respect to the A-phase of the stop target excitation position 4, that is, in a state where only the A-phase drive signal 13a is activated. Accordingly, the excitation signal from the driver IC 11 is fixed while only the A-phase excitation signal is output from the A-phase motor driver 12a.

Here, the poles of the rotor of the stepping motor 10 are drawn to the position of the A-excitation phase and are stopped and fixed.

At this time, the control signals CTL1 and CTL2 from the CPU 13 are not output, and the excitation voltage level of the A-phase excitation signal generated and output by the A-phase motor driver 12a is changed to the excitation signal accompanying the rotation control up to that time. It is the same as the voltage level.

Then, the excitation driving state based on the normal excitation voltage level of only the A-phase is continued during a fixed stop period until the damped vibration of the rotor converges.

Thereafter, during a stop holding period in which the rotor must be fixedly held at the stop position, the CPU is stopped.
(Control Unit) Only the A-phase drive signal 13a from the controller 13 is continuously output and the A-phase control signal CTL
As a result, the A-phase excitation signal generated by the A-phase motor driver 12a is output with its excitation voltage level adjusted and set to one-half of the previous level.

When the stop holding period has elapsed,
The output of the A-phase drive signal 13a and the A-phase control signal CTL1, which have been output from the CPU 13 until then, is stopped.
The output of the A-phase excitation signal at the one-half excitation voltage level is also stopped and demagnetized.

As described above, one of the stepping motors 10
In the case of the rotation control based on the two-phase excitation method, when the excitation phase is fixed at the timing of one phase excitation of the A phase or the B phase and the rotation stop control is performed, the stop until the damped vibration of the rotor converges. In the stop holding period in which the rotor needs to be fixedly held at the stop position after the fixed period, the A-phase or B-phase control signal CTL1, C-phase corresponding to the fixed excitation phase is used.
TL2 is output, whereby the excitation voltage level of the excitation signal for continuously driving the fixed excitation phase is adjusted to be set to 、, so that it is possible to reduce the power consumption due to holding the rotor stopped. The consumption of the battery power supply 15 can be suppressed. Further, heat generation of the fixed excitation phase can be suppressed.

FIG. 3 shows A- and B-phase drive signals 13a, 13b accompanying the stop control at the two-phase excitation position output from the CPU (control unit) 13 of the stepping motor control device in the 1-2-phase excitation mode, and their signals. Control signal CTL
1 is a timing chart showing a control sequence of CTL1 and CTL2 and changes in A and B phase excitation signals output from motor drivers 12a and 12b in response to the control sequence.

Based on the A-phase drive signal 13a and the B-phase drive signal 13b of the 1-2-phase excitation system (see FIG. 4), as shown in FIG.
A case will be described in which the rotor stop control is performed at the timing of the two-phase excitation.

That is, A from the CPU (control unit) 13
The phase drive signal 13a and the B-phase drive signal 13b remain in the output state of the two-phase excitation for the B + phase and the A- phase of the stop target excitation position 3, that is, the B + phase drive signal 13b and the A- phase drive signal 13a rise. As a result, the excitation signal from the driver IC 11 is transmitted from the B-phase motor driver 12b and the A-phase motor driver 12a to the B-phase motor driver 12b.
The + phase excitation signal and the A-phase excitation signal are output and fixed.

Here, the poles of the rotor of the stepping motor 10 are drawn to an intermediate position between the B + excitation phase and the A− excitation phase and are stopped and fixed.

At this time, the control signals CTL1 and CTL2 from the CPU 13 are not output, but the excitation voltage level of the A-phase excitation signal generated and output by the A-phase motor driver 12a, and generated and output by the B-phase motor driver 12b. Each of the excitation voltage levels of the B + phase excitation signal becomes the same as the excitation signal voltage level associated with the rotation control up to that point.

The excitation driving state based on the normal excitation voltage levels of the B + phase and the A- phase is continued during a fixed stop period until the damped vibration of the rotor converges.

Thereafter, during a stop holding period in which the rotor must be fixedly held at the stop position, the CPU is stopped.
(Control Unit) The B + phase drive signal 13b and the A-phase drive signal 13a from the controller 13 are continuously output, and the A-phase control signal CTL1 and the B-phase control signal CTL2
Is output, and accordingly, the B-phase motor driver 1
The B + -phase excitation signal generated by 2b and the A-phase excitation signal generated by the A-phase motor driver 12a are output with their respective excitation voltage levels adjusted and set to そ れ of those before.

Then, when the stop holding period elapses,
The output of the B + phase drive signal 13b, the A- phase drive signal 13a, the A-phase control signal CTL1, and the B-phase control signal CTL2 that have been output from the CPU 13 until then is stopped, and the B-phase motor driver 12b and the A-phase The output of the B + phase excitation signal and the A− phase excitation signal of the half excitation voltage level from the motor driver 12a for the motor is also stopped and demagnetized.

As described above, one of the stepping motors 10
In the rotation control based on the -two-phase excitation method,
When the rotation stop control is performed by fixing each excitation phase at the timing of the phase excitation, it is necessary to stop and maintain the rotor at the stop position after the stop fixing period until the damped vibration of the rotor converges. In the period, the control signals CTL1 and CTL of the A phase and the B phase corresponding to the fixed excitation phase
2 are output together, so that the excitation voltage level of the excitation signal for continuously driving the fixed excitation phase is adjusted and set to 、, so that the power consumption due to holding the rotor stopped can be reduced. Thus, the consumption of the battery power supply 15 can be suppressed. Further, heat generation of the fixed excitation phase can be suppressed.

In the above-described embodiment, in the stepping motor 10 whose rotation is controlled based on the 1-2-phase excitation method, the excitation voltage level is set to drop when the rotation of the stepping motor 10 is stopped, thereby reducing power consumption and suppressing heat generation. However, for a stepping motor whose rotation is controlled based on, for example, a one-phase excitation method or a two-phase excitation method, similarly to the above-described embodiment, the adjustment of the excitation voltage level to the fixed excitation phase during the stop holding period is adjusted. , The amount of power consumption associated with holding the rotor stopped can be reduced.
5 can be suppressed. Further, heat generation of the fixed excitation phase can be suppressed.

[0052]

As described above, according to the control apparatus for a stepping motor according to the first aspect of the present invention, at the time of motor rotation control, the motor is controlled by the excitation signal of the first voltage level which is the normal excitation voltage level. The respective excitation phases based on the excitation method are driven to control the rotation. In the case of the motor stop control, the excitation target of the stop target is driven by the excitation signal of the second voltage level lower than the normal excitation voltage level, and the stop control is performed. Therefore, the power consumption associated with the stop control can be reduced.

According to the stepping motor control apparatus of the second aspect of the present invention, in the stop holding period after the fixed supply period of the excitation signal at the first voltage level with respect to the stop target excitation phase by the motor rotation control. Since the stop target excitation phase is continuously driven and stopped and held by the excitation signal of the second voltage level lower than the normal excitation voltage level, the power consumption accompanying the stop stop period can be suppressed even if the required stop holding period is long. become able to.

Therefore, it is possible to reduce the power consumption due to the stop control of the motor and to suppress the heat generation in the excitation phase.

[Brief description of the drawings]

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

FIG. 2 is a diagram showing A- and B-phase drive signals and control signals CTL1 and CTL2 associated with stop control at a one-phase excitation position output from a CPU (control unit) of the stepping motor control device in a 1-2-phase excitation system. 9 is a timing chart showing a control sequence and changes 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- and B-phase drive signals and their control signals CTL1 and CTL2 associated with stop control in a two-phase excitation position output from the CPU (control unit) of the stepping motor control device in a 1-2-phase excitation mode. 9 is a timing chart showing a control sequence and changes in A and B-phase excitation signals output from a motor driver in accordance with the control sequence.

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

FIG. 5 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 15 ... Battery power

Claims (4)

[Claims] An excitation signal supply means for supplying an excitation signal based on a predetermined excitation method to each excitation phase of a stepping motor, and a voltage of an excitation signal supplied to each excitation phase of the stepping motor by the excitation signal supply means. Exciting voltage setting means for setting the level to one of a first voltage level and a second voltage level lower than the first voltage level; and setting the voltage level of the exciting signal set by the exciting voltage setting means to motor rotation control. A control device for a stepping motor, comprising: setting control means for setting the first voltage level and setting the second voltage level at the time of motor stop control. 2. The stepping method according to claim 1, wherein the motor stop control is a stop holding period after a fixed supply period of an excitation signal at a first voltage level with respect to a stop target excitation phase. Motor control device. 3. An excitation signal supply procedure for supplying an excitation signal based on a predetermined excitation method to each excitation phase of the stepping motor, and a voltage of the excitation signal supplied to each excitation phase of the stepping motor in the excitation signal supply procedure. An excitation voltage setting procedure for setting the level to one of a first voltage level and a second voltage level lower than the first voltage level; and setting the excitation signal voltage level set in the excitation voltage setting procedure to motor rotation control. A setting control procedure for setting the voltage to the first voltage level and setting the voltage to the second voltage level during the motor stop control. 4. The stepping method according to claim 3, wherein the motor stop control is a stop holding period after a fixed supply period of the excitation signal at the first voltage level for the stop target excitation phase. Motor control method.