JP3827889B2 - Stepping motor control method and control apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a stepping motor control method and control apparatus, and more particularly to a control method and control apparatus for further stabilizing the behavior of a stepping motor immediately after power-on.
[0002]
[Prior art]
Conventionally, stepping motors are widely used in office automation equipment such as printers. Conventionally, when controlling a stepping motor, if the motor is started after being stopped, its behavior becomes unstable, and problems such as noise, vibration, and step out occur. As techniques, for example, those described in JP-A-5-161395 and JP-A-5-328796 are already known.
[0003]
Among these, the former stops the stepping motor at a stable angle by rotating the stepping motor until a full-step driving excitation state is obtained after a motor stop request is issued, and then holding the stepping motor at a stable angle. This is to stabilize the behavior when stopping and starting driving.
In the latter case, the motor is stopped immediately when the stepping motor is requested to stop, the motor is held in the excited state immediately before the stop process in the stopped state, and the motor is stopped by performing the start process from the excited state when starting next. And stabilizes the behavior at the start.
[0004]
[Problems to be solved by the invention]
However, even with such a conventional stepping motor control method, the exact position of the magnetic pole immediately after the drive power is turned on (ON) is not clear, which may cause a deviation in the magnetic pole of the stepping motor. The problem that the operation immediately after starting the rotation of the stepping motor tends to become unstable has not been solved.
[0005]
The present invention has been made to solve such a problem, and an object thereof is to stabilize the behavior at the start of the first rotation immediately after the stepping motor is turned on.
[0006]
[Means for Solving the Problems]
In order to achieve the above object , the stepping motor control method according to the present invention applies a hold current to the excitation phase before the rotation from the stop state to the rotation state when stepping the stepping motor installed in the drawer unit. In the control method of the stepping motor that flows and holds, immediately after the power is turned on, it is determined whether or not the stepping motor can be excited by determining whether or not the extraction unit is stored in a predetermined position. Only when it is determined that the stepping motor can be excited and the stepping motor is rotated for the first time before the stepping motor is rotated for the first time. and carrying out longer than the hold at the time of rotation.
[0007]
According to this control method, immediately after the power is turned on, it is determined whether or not the stepping motor can be excited by whether or not the drawer unit is stored in a predetermined position, and the drawer unit is stored in a predetermined position and excited. Only when it is determined to be possible, hold for a longer time than usual is performed in a specific excitation phase, so there is no delay before rotation starts when the first stepping motor is driven, and before hold However, the magnetic poles can be surely matched regardless of the magnetic poles, and there is no fear of step-out at the start of rotation.
[0009]
The stepping motor control device according to the present invention also includes means for step-rotating the stepping motor installed in the drawer unit, and holding in the excitation phase before changing from the stopped state to the rotating state when step-rotating by the means. In a stepping motor control device having a holding means for holding by passing an electric current, immediately after turning on the power, whether or not the stepping motor can be excited depends on whether or not the extraction unit is housed in a predetermined position. determining means for determining, the drawer unit only when it is housed at a predetermined position said determining means determines that it is possible excitation, before the first rotating state said stepping motor, to said hold means against, the host at the time of subsequent steps rotating by passing a hold current to a specific excitation phase Than field is obtained and a hold control means for causing a long hold.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing the configuration of a control unit for carrying out the stepping motor control method as the basis of the present invention. This control unit is configured by connecting a motor driving means 2 to the stepping motor 1 and connecting a motor control means 3 to the motor driving means 2.
[0012]
The stepping motor 1 is a conventionally known stepping motor, but here, a four-phase stepping motor is used. In the case of a four-phase stepping motor, the rotor rotates by sequentially designating each excitation phase (four, A, B, a, and b).
[0013]
For example, when the stepping motor 1 is driven by 1-2 phase excitation, the designation of the excitation phase is performed alternately with the one-phase designation and the two-phase designation. Therefore, A-AB-B-Ba-a-ab-b -BA order.
When this is driven by two-phase excitation, the excitation phase is specified in the order of AB-Ba-ab-bA-AB. If the order of the phases to be excited is reversed, the rotor rotates in the reverse direction.
[0014]
The motor drive means 2 amplifies the current necessary for excitation of each excitation phase of the stepping motor 1 in response to the excitation signal input from the motor control means 3 to generate an excitation current, and applies this to each phase to be excited. It is a driver circuit that drives the stepping motor 1 by supplying it.
[0015]
The motor control means 3 is a control microcomputer, generates an excitation signal synchronized with a motor control pulse (drive pulse) for driving the stepping motor 1, and inputs the excitation signal to the motor drive means 2.
[0016]
In the above configuration, when the stepping motor 1 is driven, a process called “hold” is executed to start the rotation. This process is a process for matching the magnetic poles of the rotor and the stator by exciting a certain excitation phase by passing a hold current for a certain period of time. By executing this process, even if the magnetic poles of the rotor and the stator are misaligned, the rotor magnetic poles are matched with the stator magnetic poles at the start of rotation to eliminate the misalignment. Can be stabilized.
[0017]
In performing this hold, during normal step rotation, since the magnetic pole is rarely greatly displaced at the time of starting rotation, it is performed only for a very short time, for example, 50 ms. Even in such a short time, the desired purpose can be achieved by matching the magnetic poles. For example, when driving the stepping motor 1 with 1-2 phase excitation, if the excitation phase immediately before stopping is the Ba phase (excitation was performed with the Ba phase), the magnetic poles will shift when the rotation is next performed. Even in the ab phase, if the excitation is performed in the Ba phase for 50 ms, the deviation can be eliminated and the magnetic poles can be matched. Thereafter, it can be rotated without causing a step-out.
[0018]
However, since the position of the magnetic pole is not known when the stepping motor 1 is rotated for the first time after the control unit is turned on, a normal current step is performed by supplying a hold current to a specific excitation phase, for example, the B phase. Hold is executed for a longer time (for example, for 100 ms) than during rotation. As a result, even if the magnetic pole is in the b phase of the counter electrode, it can be surely matched with the B phase. Therefore, in the subsequent rotation of the stepping motor, it is possible to rotate without causing a step-out.
This function is a function of the hold control means in the stepping motor control apparatus according to the present invention, and is executed by the motor control means 3 which is a control microcomputer of the control unit shown in FIG.
[0019]
FIG. 2 is a block diagram showing a configuration of a control unit for carrying out the stepping motor control method according to the present invention.
In this control unit, the monitoring sensor 4 is connected to the motor control means 3 of the control unit shown in FIG. 1, but the other configuration is the same as that of the control unit shown in FIG.
[0020]
Monitoring sensor 4 is a sensor for inputting information required for motor control unit 3 in order to immediately after the power is turned stepping motor 1 determines whether excitable.
In this case, the information necessary to determine whether or not the stepping motor 1 can be excited will be described in detail later. For example, is a current for driving the stepping motor 1 supplied to enable excitation? Information corresponding to whether or not. The monitoring sensor 4 inputs this information to the motor control means 3.
[0021]
Therefore, in this control unit, the motor control means 3 determines whether or not the stepping motor 1 can be excited based on the information from the monitoring sensor 4 immediately after the power is turned on, and only when it is determined that the stepping motor 1 can be excited. As in the case of the example, a hold current is supplied to a specific excitation phase, and the hold is performed for a longer time than the hold during the subsequent step rotation.
[0022]
That is, in the control unit shown in FIG. 2, the monitoring sensor 4 and the motor control means 3 determine whether the stepping motor 1 can be excited immediately after the power is turned on, and determine that it can be excited. Only when this is done, the function of the hold control means for executing the hold longer than usual is fulfilled.
[0023]
Next, the operation of the above-described control unit will be specifically described by taking as an example a roll paper feed unit which is an optional paper feed unit of a facsimile machine incorporating the control unit. FIG. 3 is a conceptual diagram illustrating the main configuration of the roll sheet feeding unit.
[0024]
As shown in FIG. 3, the roll paper feeding unit includes a housing 10 and a drawer unit 20 in which a stepping motor 21 is installed.
As shown in the figure, the housing 10 includes a power source 11 that can be turned on and off with a switch, a control microcomputer 12, a power detection sensor 13 that detects whether the power source 11 is turned on, and an open / close state of the drawer unit 20. The open / close detection sensor 14 for detecting the above is appropriately arranged and electrically connected to each other.
[0025]
The power supply 11 is a DC power supply that outputs a voltage of plus 24 volts, and supplies a current necessary for driving the stepping motor 21 installed in the drawer unit 20.
The control microcomputer 12 outputs a signal necessary for driving the stepping motor 21 by receiving a current supplied from a 5-volt power supply (not shown) that is not linked to the power supply 11, and drives or stops the stepping motor 21. To control. This corresponds to the motor control means 3 of the control unit shown in FIGS.
[0026]
The power supply detection sensor 13 monitors whether or not current can be supplied from the power supply 11 to the stepping motor 21 by detecting whether or not the power supply 11 is turned on, and sends a signal corresponding to the motor control means. 3 is output to the control microcomputer 12.
[0027]
The open / close detection sensor 14 monitors whether or not current can be supplied from the power supply 11 to the stepping motor 21 by detecting whether the drawer unit 20 is housed in a predetermined position or not. A corresponding signal is output to the control microcomputer 12 which is the motor control means 3.
These power supply detection sensor 13 and open / close detection sensor 14 correspond to the monitoring sensor 4 of the control unit shown in FIGS. 1 and 2.
[0028]
The drawer unit 20 is configured to be able to store and remove the roll paper of the roll paper feed unit and to be taken in and out in the direction indicated by the arrow a so that the roll paper can be additionally supplied.
As shown in FIGS. 4 and 5, this drawer unit 20 has roller pairs 22a, 22b, 22c, and 22d installed at four locations so that the central axis is along the drawing direction, and roll paper is placed in a predetermined storage section 20a. 23 is accommodated. Then, the roll paper 23 is conveyed along each of the roller pairs 22a, 22b, 22c, and 22d, and is discharged from the side surface 20b of the drawer unit 20.
[0029]
Each roller pair 22a, 22b, 22c, 22d and the roll paper 23 are installed in an arrangement as shown in FIGS. A decurler 24 is installed in the vicinity of the roll paper 23, and a pickup roller pair 22a, a feed roller pair 22b, a relay roller pair 22c, and a transport roller pair 22d are sequentially disposed on the downstream side thereof.
[0030]
A paper end sensor 25 and a cutter 26 are installed between the pickup roller pair 22a and the feed roller pair 22b, and a guide plate 27 is installed between the feed roller pair 22b and the relay roller pair 22c. . When each of these roller pairs is driven by the stepping motor 21, it rotates in the direction indicated by the arrow in FIG.
[0031]
In the drawer unit 20 shown in FIG. 3, a stepping motor 21 for driving each roller pair 22a, 22b, 22c, 22d is installed inside, but this stepping motor 21 is for driving this. It has a built-in driver. This driver corresponds to the motor drive means 2 of the control unit shown in FIGS. Accordingly, the stepping motor 21 serves as both the stepping motor 1 and the motor driving means 2 of the control unit.
[0032]
When the drawer unit 20 is housed in the housing 10, the power source 11 and the stepping motor 21 are electrically connected by the wirings 15 and 16, and the stepping motor 21 is driven by supplying current from the power source 11. It is supposed to be. When the stepping motor 21 is rotated by receiving a current supplied from the power supply 11, the roller pairs 22a, 22b, 22c, and 22d are driven, and the roll paper 23 is conveyed by the roller pairs.
[0033]
FIG. 3 shows a state in which the wires 15 and 16 are physically disconnected. This is a state in which the supply of current from the power source 11 to the stepping motor 21 is stopped by pulling out the drawer unit 20. An example is schematically shown. Therefore, the state in which current is supplied from the power source 11 to the stepping motor 21 and the state in which the current is stopped are switched by the withdrawal and withdrawal of the drawer unit 20.
[0034]
Next, a stepping motor control method performed in the roll sheet feeding unit of the facsimile apparatus having the above configuration will be described with reference to the flowcharts shown in FIGS.
[0035]
First, when the power supply 11 is turned on, the control microcomputer 12 starts the processing shown in the flowchart of FIG. 6 and inputs information from the facsimile apparatus main body in step 101. Then, in step 102, it is determined whether or not the input information is information corresponding to a drive request for the stepping motor 21. If the input information is information corresponding to a drive request, the subsequent processing is executed. Return to 101.
[0036]
If it is determined in step 102 that the information corresponds to the drive request, in step 103, the control microcomputer 12 functions as a hold control means, and the driver built in the stepping motor 21 is longer than the normal hold. A long-time hold excitation signal is output so as to function as a hold means for executing the hold.
[0037]
When the stepping motor 21 receives this excitation signal, the stepping motor 21 is supplied with a current from the power supply 11 and performs step rotation by the driver. By holding a hold current, a longer hold than the normal hold is executed.
[0038]
At this time, the stepping motor 21 performs the hold at a specific current value for a longer time than normal, for example, 100 ms, instead of the normal hold. Then, since the rotor can be held in a specific excitation phase regardless of the location, for example, even if the rotor is in the b phase of the counter electrode, the rotor can be reliably held in the B phase to match the position of the rotor. . Therefore, the rotor does not exhibit unstable behavior or step out during the subsequent step rotation, exhibits stable driving, and each pair of rollers 22a to 22d driven by the stepping motor 21. Also, the roll paper 23 is conveyed stably. Then, in the subsequent step 104, when hold is executed thereafter, the normal hold is set.
[0039]
In the case of controlling as described above, holding for a longer time than usual is performed in a specific excitation phase immediately after the power supply 11 is turned on. For this reason, if there is a drive request from the facsimile apparatus immediately after the power supply 11 is turned on, a long time hold is executed before the rotation is first made, thereby causing a delay until the stepping motor 21 starts to rotate. become.
[0040]
In order to eliminate this delay, the power detection sensor 13 and the open / close detection sensor 14 functioning as the monitoring sensor 4 monitor whether or not current can be supplied to the stepping motor 21, that is, whether or not excitation is possible, and control microcomputer 12 is controlled based on the monitoring result.
The operation of the control microcomputer 12 in this case is performed according to the flowchart shown in FIG.
[0041]
First, when the power supply 11 is turned on, the control microcomputer 12 starts processing, and in step 201, a hold time is set. Here, a time for performing a long-time hold to be performed later is set.
[0042]
In subsequent step 202, when the power detection sensor 13 detects the power-on state and outputs a signal corresponding to the state, the control microcomputer 12 inputs this signal. When the open / close detection sensor 14 detects the open / close state of the drawer unit 20 and outputs a signal corresponding to the open / close state, the control microcomputer 12 also inputs the signal.
[0043]
When these two kinds of signals are input, the control microcomputer 12 determines whether the stepping motor 21 can be excited by supplying a current from the power source 11 in the next step 203 and determines that the excitation is possible. Sometimes, in step 204, a hold excitation signal is output as a control signal for the driver to function as a hold means for performing the hold. If it is not determined that excitation is possible, the process returns to the hold time setting process in step 201.
[0044]
In this case, it is determined that excitation is possible. The input signal from the power supply detection sensor 13 indicates the ON state of the power supply 11, and the input signal from the open / close detection sensor 14 indicates the storage state of the drawer unit 20. Is the case. Therefore, when the power supply 11 is in an OFF state or when the drawer unit 20 is pulled out, long-time holding is not executed.
[0045]
When the hold excitation signal is output, the hold is executed at a specific excitation phase of the stepping motor 21, but the current supply from the power source 11 is stopped during the hold and the excitation becomes impossible. In the case where the drawer unit 20 has been pulled out, for example, the control microcomputer 12 determines in step 205 that excitation is impossible, and in step 206 a signal for stopping the hold is output to step 201. Return.
[0046]
In this case, when the drawer unit 20 is housed and the current can be supplied, that is, when it is determined that the current can be supplied to any input of the power supply detection sensor 13 and the open / close detection sensor 14, the hold is performed again. Is executed.
[0047]
In step 207, the control microcomputer 12 determines whether or not the held hold corresponds to a predetermined time, that is, the time set in step 201, and if so, that is, If the hold is performed for a long time, the process is terminated. If not, that is, if the set time is not reached, the process returns to step 202.
[0048]
When this control is performed, the rotor can be held in a specific excitation phase no matter where it is located. Therefore, the position of the rotor can be specified, and the rotor exhibits unstable behavior during subsequent step rotation, There is no adjustment, and stable driving is shown. Moreover, since a long-time hold is performed only when it is determined that excitation is possible, there is no delay until the stepping motor 21 starts rotating.
[0049]
【The invention's effect】
According to the control method and control apparatus for a stepping motor of the present invention, when the stepping motor starts rotating immediately after the power is turned on, the hold for a longer time than usual is executed with a specific excitation phase. Even if it is, the magnetic poles can be surely matched, and there is no possibility of step-out at the start of rotation. Therefore, the stepping motor exhibits a stable behavior.
[0050]
Also immediately after the power is turned on, it is determined whether or not it is possible to excite the stepping motor, since the only long hold when it is determined that it is possible excitation produces a delay before the stepping motor starts to rotate Less.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a configuration example of a control unit for carrying out a stepping motor control method as a basis of the present invention;
FIG. 2 is a block diagram showing a configuration of an embodiment of a control unit for carrying out a stepping motor control method according to the present invention.
3 is a conceptual diagram showing a main configuration of a roll paper feeding unit that is an optional paper feeding unit of a facsimile apparatus incorporating the control unit shown in FIG. 2;
4 is a side view showing a positional relationship between rollers and roll paper disposed in the drawer unit in FIG. 3; FIG.
FIG. 5 is a plan view of the same.
6 is a flowchart of a stepping motor control process performed in an optional paper feed unit of the facsimile apparatus incorporating the control unit shown in FIG.
FIG. 7 is a flowchart showing details of hold control in the stepping motor control process.
[Explanation of symbols]
1, 2: 1: Stepping motor 2: Motor drive means 3: Motor control means 4: Monitoring sensor 10: Housing 11: Power supply 12: Control microcomputer 13: Power supply detection sensor 14: Open / close detection sensors 15, 16: Wiring 20: Drawer units 22a to 22d: roller pair 23: roll paper

Claims (2)

In the stepping motor control method for holding by passing a hold current to the excitation phase before changing from the stopped state to the rotating state when stepping the stepping motor installed inside the drawer unit ,
Immediately after turning on the power, whether or not the stepping motor can be excited is determined by whether or not the drawer unit is stored in a predetermined position, and the drawer unit is stored in a predetermined position and can be excited. Only when the determination is made, before the stepping motor is first rotated, a hold current is supplied to a specific excitation phase to perform the hold, and the hold is performed for a longer time than the hold at the subsequent step rotation. A stepping motor control method characterized by the above. A stepping motor for stepping the stepping motor installed in the drawer unit; and a holding unit for holding by passing a hold current through the excitation phase before changing from the stopped state to the rotating state when the stepping motor is rotated by the means. In stepping motor control device,
Judgment means for judging whether the stepping motor can be excited immediately after the power is turned on or not based on whether or not the drawer unit is housed in a predetermined position, and whether the drawer unit is housed in a predetermined position Only when it is determined that the means can be excited, before the stepping motor is first rotated, a hold current is supplied to the holding means in a specific excitation phase and the hold at the subsequent step rotation is performed. control device for a stepping motor, characterized in that a hold control means for causing the long hold than.

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