JPH06178596A - Controller of stepping motor - Google Patents

Abstract

PURPOSE:To detect a rotation signal of a motor and to diagnose the state of rotation of the motor due to the voltage induced in a primary winding and to correct the trouble when the trouble occurs, without using another driving circuit or outside sensor. CONSTITUTION:Detection windings [a] and [b] are installed respectively on primary windings A1 and B1 wound round a stator of a stepping motor 2. Induced voltage E2a and E2b output by the detection windings are signal-processed sequentially by a rotation detecting circuit 1. In the rotation detecting circuit 1, an output amplifying circuit 3 that adjusts induced voltage level, a signal processing circuit 4 that filters noise, a subtracting circuit 5 that filters an unwanted voltage component, using the voltage output from a charging and discharging circuit 8, a waveform reshaping circuit 6 that converts a signal to the one that can be digitized a diagnosing circuit 7 that determines whether the motor rotates normally, a controlling circuit 9a that controls the motor according to the output of the diagnosing circuit 7 and a distributing circuit 9, a power transistor circuit 12, and other circuits are installed. Due to this structure, an easy self-control of the stepping motor is available.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention detects a rotational state such as the rotational position and speed of a stepping motor to diagnose whether or not the stepping motor is rotating normally. The present invention relates to a stepping motor control device having correction means for returning an abnormal signal and returning to a normal state at the same time.

[0002]

2. Description of the Related Art In recent years, the use of stepping motors has been rapidly expanded for both industrial and general use. Among them, a motor with a rotation detection function has been widely used to detect an abnormality such as step-out, and a correction operation can be performed even in the case of an abnormality.

A conventional stepping motor control device with a rotation detecting function will be described below with reference to the drawings.

As shown in FIG. 13A, a conventional controller for a stepping motor with a rotation detecting device using a potentiometer as a rotation detecting sensor is a rotor 2R.
And the main winding A _{1 on} the stator of the stepping motor 2,
A ₂ , B ₁ and B ₂ are wound and the potentiometer 21 is used to mechanically connect the stepping motor 2 and the joint 22. The power supply 10 and the drive circuit 23 of the stepping motor 2 are connected to the main windings A ₁ , A ₂ , B ₁ , B _{2 of the} stator, respectively.
It is connected to the. Output terminal E of potentiometer 21
Reference numeral 21 is connected to a control circuit 23a incorporated in the drive circuit 23.

The relationship and operation of each component will be described below. First, the drive circuit 23 drives the main windings A ₁ , A ₂ , B
₁ and B ₂ are each excited with the phase shown in FIG. 2 described later. This causes the rotor 2R of the stepping motor 2 to rotate,
When this rotor 2R rotates, the joint 22 rotates, and
As shown in (b), the output voltage E21 of the potentiometer 21 changes according to the rotation angle.

In this way, the output voltage E2 of the potentiometer 21 in the control circuit 23a in the drive circuit 23 is increased.
By detecting 1, it is possible to judge whether or not the stepping motor 2 is rotating normally, and it is possible to perform the correction operation even in the case of an abnormality.

As another method, a method of detecting rotation by utilizing an induced voltage of a stepping motor has been proposed. As a means therefor, a transformer is used outside the motor and one winding of the transformer is used. And the main winding of the motor 1
There is also one that directly connects two phases and uses an induced voltage generated on the secondary side of the transformer.

[0008]

However, in the above-mentioned conventional structure, in order to drive the stepping motor and detect the rotation of the motor, a distribution circuit for sequentially switching the excitation to the outside of the motor, a power transistor circuit, and a constant voltage circuit are included. In addition to the motor drive circuit, a separate sensor such as a potentiometer or an external component with a relatively large current capacity such as a transformer is required, and the number of required components and the number of input / output terminals are large. There was a problem that there were few price advantages. In addition, when a sensor such as a potentiometer is attached to the outside, it is necessary to couple with a motor or a load, so the sensor has a hysteresis characteristic due to the influence of the coupling, and there is a problem that the position accuracy deteriorates. It was

The present invention solves the above-mentioned problems of the prior art by using a separate distribution circuit, a power transistor circuit, a motor drive circuit such as a constant voltage circuit, and external parts such as a sensor outside the conventional motor. Instead, the stepping motor is driven, the rotation signal of the rotor is obtained from the induced voltage generated in the main winding of the stepping motor, the rotation state of the motor is diagnosed by this signal, and the self-correction operation is performed in the case of an abnormality It is an object of the present invention to provide a control device of.

[0010]

In order to achieve this object, a controller for a stepping motor according to the present invention comprises a main winding wound around a stator of a stepping motor, a detection winding, and a printed circuit board. Made distribution circuit, power transistor circuit, constant voltage circuit, charging / discharging circuit, subtraction arithmetic circuit that subtracts output of charging / discharging circuit from output of detection winding, and output of at least one phase of charging / discharging circuit An output amplification circuit that amplifies the output signal, a subtraction calculation circuit, a signal processing circuit that processes the output signal of the detection winding or the charge / discharge circuit, a waveform shaping circuit that shapes the output waveform of the signal processing circuit, and an output of the waveform shaping circuit. It has a configuration including a diagnostic circuit that detects and diagnoses whether the motor is rotating normally, and a control circuit that controls the motor according to the output of the diagnostic circuit. Further, by newly providing an applied voltage subtraction circuit for subtracting the voltage applied to the main winding of the stepping motor, the detection winding can be eliminated.

[0011]

According to the present invention, in the above structure, the stepping motor operates by supplying only a power source and one input signal, detects the induced voltage generated in the main winding by the main winding or the detection winding, and induces the induced voltage. The stepping motor rotates normally by amplifying the voltage with the amplification circuit, processing it with the signal processing circuit, calculating it with the subtraction calculation circuit, shaping it with the waveform shaping circuit, diagnosing it with the diagnostic circuit, and controlling it with the control circuit. Whether or not it is possible to carry out the self-correction operation in the case of abnormality.

[0012]

(Embodiment 1) A first embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, stepping of this embodiment
The motor control device includes an output amplifier circuit 3 and a signal processing circuit.
4, subtraction arithmetic circuit 5, waveform shaping circuit 6, and diagnostic circuit 7
Has a rotation detection circuit 1 including a stepping motor 2
Main winding A wound around the stator of ₁, A₂, B₁, B₂Induced in
As a means for detecting the induced voltage generated, the main winding A₁, A₂, B
₁, B₂Apart from this, it has detection windings a and b. And
The detection winding a is the main winding A₁And the detection winding b is the main winding B₁And each
Are magnetically coupled and output from the detection windings a and b.
The output signal is output amplification circuit 3, signal processing circuit 4, subtraction operation
Processed via circuit 5, waveform shaping circuit 6 and diagnostic circuit 7.
Be done. Furthermore, the charge / discharge circuit 8 and the power transistor circuit
12 and the distribution circuit 9 through the control circuit built in the distribution circuit 9.
It is controlled by the control circuit 9a. The power supply 10 and the constant voltage circuit
11 is provided for the stepping motor 2
Signals are input and output from the child 14.

The relationship and operation of each component will be described below with reference to FIGS. First, in FIG. 1, a command pulse is input to the CW or CCW of the input / output terminal 14,
The distribution circuit 9 sequentially excites the main windings A ₁ , A ₂ , B ₁ , and B _{2 in} phases as shown in FIG. 2, and the rotor 2R of the stepping motor 2 rotates. When this rotor 2R rotates,
The induced voltages E2a and E2b are generated, and the induced voltages E2a and E2b as shown in FIG. 3A are taken out from the detection windings a and b as signals. However, in the induced voltage signal waveforms E2a and E2b, the induced component by the rotor 2R of the stepping motor 2 and the main windings A ₁ , A ₂ , B ₁ ,
Since the induction component due to the current flowing through B ₂ is combined, the induction component due to the current flowing through the main windings A ₁ , A ₂ , B ₁ , and B ₂ is removed to induce the rotor 2R of the stepping motor 2. It is only an ingredient. Here, the rotation signal of the motor can be obtained by signal-processing only the inductive component of the rotor 2R.

Next, a method of obtaining the rotation signal will be described. First, the induced voltages E2a and E2b appearing in the detection windings a and b in FIG.
Of the main windings A ₁ , A ₂ ,
The induction component due to the current flowing in B ₁ and B ₂ is included,
It is necessary to remove the induced component due to the current flowing through the main windings A ₁ , A ₂ , B ₁ and B ₂ . Here, the currents flowing through the main windings A ₁ , A ₂ , B ₁ , and B ₂ are respectively iA ₁ , iA ₂ , and
If iB ₁ and iB ₂ and the induced voltage components due to this current are EA ₁ , EA ₂ , EB ₁ and EB ₂ , respectively,
Is established.

[0016]

[Equation 1]

Therefore, this EA ₁ , EA ₂ , EB ₁ ,
The same inductive component as EB ₂ is formed by some method, and the formed component is subtracted from the induced voltages E2a and E2b appearing in the detection windings a and b.
Only the induced component due to can be obtained. The charge / discharge circuit 8 is used to remove the induction components EA ₁ , EA ₂ , EB ₁ , EB ₂ due to the current flowing in the main windings A ₁ , A ₂ , B ₁ , B ₂ .
That is, in the charging / discharging circuit 8, the excitation timing shown in FIG. 2 is utilized to first induce the currents iA ₁ , iA ₂ , iB ₁ , iB ₂ flowing in the main windings A ₁ , A ₂ , B ₁ , B _2. Waveform E8A ₁ , which is created by holding the peak voltage value of the voltage waveform for a moment and then discharging this peak voltage value,
E8A ₂ , E8B ₁ , E8B ₂ are the main windings A ₁ , A ₂ , B ₁ ,
The fact that the waveforms are similar to the induced components due to the currents iA ₁ , iA ₂ , iB ₁ and iB ₂ flowing in B ₂ is used. That is, the following (Equation 2) is used.

[0018]

[Equation 2]

Therefore, if appropriate constants K _{1 to} K ₈ are selected according to (Equation 1) and (Equation 2), the main windings A ₁ , A ₂ , B ₁ , and B ₂ are applied to the main windings A ₁ by using the charge / discharge circuit 8. Flowing current iA ₁ , i
Induced components EA ₁ , EA ₂ , E by A ₂ , iB ₁ , iB ₂
B ₁ and EB ₂ can be removed. That is, in (Equation 1) and (Equation 2), constants K ₁ = K ₅ , K ₂ = K ₆ , K
_{If 3} = K ₇ and K ₄ = K ₈ , the following (Equation 3) is established.

[0020]

[Equation 3]

Next, how to select appropriate constants of (Equation 1) and (Equation 2) will be described. Here, the constants of (Equation 1) and (Equation 2) vary depending on the motor, and the constants of the charging / discharging circuit 8 also vary, and a signal other than the basic signal, for example, a noise signal is mixed. You have to consider the possibilities.

Therefore, in FIG. 1, the voltage levels of the inductive components E2a and E2b from the detection windings a and b are adjusted by the output amplifier circuit 3 in order to absorb the variations of the stepping motor 2 and the charging / discharging circuit 8. E3a and E respectively
3b, and then in the signal processing circuit 4, for example,
The signals E4a and E4b from which noise and the like have been removed by the low pass filter and the band pass filter are input to the subtraction calculation circuit 5. In FIG. 3A, E2a, E2b,
E3a, E3b and E4a, E are shown in FIGS.
4b shows the waveform.

In this way, in the subtraction operation circuit 5, the outputs E4a, E4b of the signal processing circuit 4 and the outputs E8A ₁ , E8A ₂ , E8B ₁ , E8B _{2 of} the charging / discharging circuit 8 are subjected to the subtraction processing, and the main winding Induction components EA ₁ and E due to currents iA ₁ , iA ₂ , iB ₁ and iB ₂ flowing in A ₁ , A ₂ , B ₁ and B ₂ of the line
A ₂ , EB ₁ and EB ₂ can be removed.

FIG. 4 shows the output waveform E8 of the charge / discharge circuit 8.
A ₁ , E8A ₂ , E8B ₁ , E8B ₂ and subtraction operation circuit 5
Shows the output waveform _{E5A 1, E5A 2, E5B 1} , E5B 2. The outputs E5A ₁ , E5A ₂ , E5 of the subtraction calculation circuit 5
B ₁ and E5B ₂ are input to the waveform shaping circuit 6.

Next, the waveform shaping circuit 6 in FIG. 1 will be described. First, when the induced voltage _{E5A 1, E5A 2, E5B 1} , E5B 2 in phase relation as shown in FIG. 4 is input to the waveform shaping circuit 6, the waveform shaping circuit 6, and FIG. 4 (b)
First, in the comparator, E5A ₁
And plus side for E5B ₁ , E5A ₂ and E5
The B ₂ is converted to a pulse waveform as each reference voltage and the minus side. This is the subtraction arithmetic circuit 5 in FIG.
Input waveforms E4a, E4b and E8A ₁ , E
The potential level on the plus side and the potential level on the minus side of 8A ₂ , E8B ₁ , and E8B ₂ are not always the same level due to magnetic influences, etc., and only one of the plus side and the minus side is completely subtracted. This is because it cannot be done.
The waveform pulse-converted by the comparator is shown in FIG.
E56A ₁ , E56A ₂ , E56B ₁ shown in (a),
It is E56B ₂ .

However, E56A in FIG.₁，
E56A₂, E56B₁, E56B₂Is E in FIG.
5A₁, E5A₂, E5B₁, E5B₂The plus side of
Pulse waveform with either negative side as reference voltage
Is a waveform that has an unstable element,
Extremely high for pulse waveforms with 50% operating duty
Peg. Therefore, a pulse wave with a stable operation duty of 50%
A JK flip-flop is used as a waveform conversion means
By using each waveform E56A of FIG. ₁, E
56A₂, E56B₁, E56B₂Operating duty 50
Convert to a pulse waveform of%.

FIG. 5B shows waveforms E6a and E6b having an operation duty of 50%. E6a is shown in FIG.
(A) E56A ₁ and E56A ₂ are shown in FIG.
Each of E56B ₁ and E56B ₂ in (b) is waveform-shaped. This waveform shaping circuit 6 is shown in FIG.
The block diagram of is shown. In this way, the diagnostic circuit 7 of FIG. 1 determines whether or not the stepping motor 2 is normally rotating by using the pulse waveform having the operation duty of 50% which has been waveform-shaped as described below. be able to.

The diagnostic circuit 7 is a circuit for diagnosing whether the motor is rotating normally by an up / down counter.
That is, when the motor is rotating normally, only one of the up pulse train and the down pulse train appears, but when the motor is abnormal, both the up pulse train and the down pulse train appear.

FIGS. 6A and 6B respectively show the rotor 2
This is an example of the case where R does not step out and rotates normally. Further, FIGS. 6C and 6D each show an example when the rotor 2R goes out of step, that is, when the motor becomes abnormal. In FIG. 6, E7a and E7b are output waveforms of the diagnostic circuit 7 when the outputs E6a and E6b of the waveform shaping circuit 6 in FIG. 1 are input to the diagnostic circuit 7, respectively. A concrete processing method of the diagnostic circuit 7 is shown in FIG.
A block diagram of the diagnostic circuit 7 is shown in FIG.

Next, the control circuit 9a in FIG. 1 will be described. First, in FIG. 1, the output E7 of the diagnostic circuit 7
a and E7b are input to the control circuit 9a. This E7
Output examples of a and E7b are shown in FIG. 6 (a), (b),
As shown in (c) and (d), when the motor is rotating normally, only one of the up pulse and the down pulse shows a pulse train, but when the motor is abnormal, both the up pulse train and the down pulse train. However, since the number of steps out of step accurately appears as the number of pulses, even if step out occurs, normal control can be performed by performing a correction operation for the number of steps out of step. The control circuit 9a in FIG. 1 is a circuit that performs this correction operation, and operates the distribution circuit 9 in accordance with a command from this control circuit 9a. For example, in FIG. 6 (d), a pulse train of a total of 2 pulses appears in the down pulse E7b. This is compared with FIG. 6 (a). So, it means that two pulses are out of sync. Therefore, the control circuit 9a can normally control the stepping motor 2 by outputting to the distribution circuit 9 a command to rotate the motor in the forward direction by two pulses and performing a correction operation. In addition to the method of adding the forward rotation or reverse rotation step number as the control method, it is possible to easily hold the stepping motor 2 at the moment when the abnormal signal pulse is input.
Further, by detecting the phase of the output of the diagnostic circuit 7 in the control circuit 9a, it is possible to prevent step-out by switching the excitation phase or issuing a command to increase or decrease the phase current. Further, the abnormality content can be output to the outside of the motor through the CK of the motor input / output terminal 14.

As described above, according to this embodiment, the stepping motor operates by supplying only the power source and one input signal, and the detection windings a and b provided separately from the main winding of the motor. By providing, it is possible to detect the rotation signal of the rotor 2R without using an external component having a large capacity,
It is possible to diagnose whether or not the motor is rotating normally, perform a self-correction operation even in the case of abnormality such as step-out, and perform so-called closed loop control that does not cause step-out. Needless to say, even if the charging / discharging circuit 8 is replaced with a digital filter, the same operation is performed.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to the drawings.

As shown in FIG. 8, the control device for the stepping motor according to the present embodiment includes an output amplifier circuit 3, a signal processing circuit 4, a subtraction operation circuit 5, a waveform shaping circuit 6 and a diagnostic circuit 7.
1 is different from the configuration of FIG. 1 in that it has a main winding A formed on the stator of the stepping motor 2.
_1, A _2, B _1, as the detection means of the induced voltage induced in B _2, the main winding A _1, A _2, B _1, another detection coil a and B _2, b
This is the point that is unnecessary. However, the main windings A ₁ , A ₂ ,
Signals EA ₁ , EA ₂ , EB ₁ , E output from B ₁ , B ₂
B ₂ is processed through the output amplification circuit 3, the signal processing circuit 4, the subtraction calculation circuit 5, the waveform shaping circuit 6 and the diagnostic circuit 7. Further, the charge / discharge circuit 8 and the power transistor circuit 1
2, the distribution circuit 9 and the applied voltage subtraction circuit 13, and is controlled by the control circuit 9a incorporated in the distribution circuit 9. In addition,
A power supply 10 and a constant voltage circuit 11 are provided, and signals are input to and output from the input / output terminal 14 with respect to the stepping motor 2.

The relationship and operation of each component will be described below with reference to FIGS. First, in FIG. 8, the main windings A ₁ , A ₂ , B ₁ and B ₂ are sequentially excited in the phases as shown in FIG. As a result, the rotor 2R of the stepping motor 2 in FIG. 8 rotates. And this rotor 2R
Is rotated, as shown in FIG. 9A, the induced voltage EA
₁ , EA ₂ , EB ₁ , EB ₂ are generated, and the main windings A ₁ , A ₂ , B are generated.
The induced voltages EA ₁ , EA ₂ , EB ₁ and EB ₂ are taken out from ₁ and B ₂ as signals. This induced voltage signal waveform E
A _1, EA _2, EB _1, the EB ₂ is the induced component due to the rotor 2R of the stepping motor 2 in FIG. 8, the main winding A
_{Since the} induced component due to the current flowing in ₁ , A ₂ , B ₁ and B ₂ and the applied voltage component are combined, the main windings A ₁ , A ₂ ,
By removing the induced component and the applied voltage component due to the currents flowing in B ₁ and B ₂ , only the induced component of the rotor 2R of the stepping motor 2 becomes. Here, the rotation signal of the motor can be obtained by signal-processing only the inductive component of the rotor 2R.

Next, a method for obtaining the rotation signal will be described.
To do. First, the main winding A in FIG. ₁, A₂, B₁, B₂To
Appearing induced voltage EA₁, EA₂, EB₁, EB₂In the
The induced component of the rotor 2R of the stepping motor 2
Winding A₁, A₂, B₁, B₂Induced by current flowing in the
And the applied voltage component is included.₁，
A₂, B₁, B₂Component and application due to current flowing in
It is necessary to remove the voltage component. Where this lord
Winding A₁, A₂, B₁, B₂The current flowing in each is iA₁, I
A₂, IB₁, IB₂And the induced voltage component due to this current
Each Ea₁, Ea₂, Eb₁, Eb₂, By rotor 2R
Induction component is ERa₁, ERa₂, ERb₁, ERb₂,Also
Applied voltage component is VA₁, VA₂, VB₁, VB₂Then,
The following (Equation 4) is established.

[0036]

[Equation 4]

Therefore, this Ea ₁ , Ea ₂ , Eb ₁ ,
The same component as Eb ₂ is formed by some method, and the formed component is subtracted from the induced voltages EA ₁ , EA ₂ , EB ₁ , EB ₂ appearing in the main windings A ₁ , A ₂ , B ₁ , B _2. If the applied voltage components VA ₁ , VA ₂ , VB ₁ and VB ₂ are further subtracted, the induced components ERa ₁ and ER by the rotor 2R to be obtained are obtained.
Only b ₁ , ERa ₂ and ERb ₂ can be obtained.

Here, first, referring to FIG.
Using the subtraction circuit 13, the main winding A ₁, A₂, B₁, B₂To
Applied voltage component VA as shown in FIG.₁, VB₁, V
A₂, VB₂Get rid of. This applied voltage component is shown in FIG.
The waveform of the power supply 10 is set to the excitation timing of each phase shown in FIG.
You can easily obtain it by using the ring. According to
Output waveform E1 of the applied voltage subtraction circuit 13 in FIG.
3a₁, E13b₁, E13a₂, E13b₂Is shown in FIG.
become that way. Using (Equation 4), the following (Equation 5) is
To establish.

[0039]

[Equation 5]

Next, referring to FIG. 8, the charging / discharging circuit 8 is used.
Use the main winding A₁, A₂, B₁, B₂Depending on the current flowing through
Inducing component Ea₁, Ea₂, Eb₁, Eb₂Get rid of. sand
That is, in FIG. 8, the charging / discharging circuit 8 has the excitation tie of FIG.
First, the main winding A₁, A₂, B₁, B₂To
Flowing current iA₁, IA₂, IB₁, IB₂Induced by
Hold the peak voltage value of the voltage waveform for a moment and then
Waveform E created by discharging the peak voltage value of
8A₁, E8A₂, E8B₁, E8B₂Is the main winding A ₁, A₂，
B₁, B₂Current iA₁, IA₂, IB₁, IB₂By
The fact that the waveform is similar to the induced component is used. sand
That is, the following (Equation 6) is used in FIG.

[0041]

[Equation 6]

Therefore, from (Equation 4) and (Equation 6),
Appropriate constant K₁~ K₈If you select, using the charge and discharge circuit 8,
Main winding A₁, A₂, B₁, B₂Current iA₁, IA₂，
iB ₁, IB₂Induced component Ea by₁, Ea₂, Eb₁, E
b₂Can be removed. That is, (Equation 4),
In (Equation 6), the constant K₁= K_Five, K₂= K₆, K₃=
K₇, K_Four= K₈Then, the following (Equation 7) can be established.
Becomes

[0043]

[Equation 7]

Next, how to select appropriate constants of (Equation 4) and (Equation 6) will be described. Here, the constants of (Equation 4) and (Equation 6) vary depending on the motor, and the constants of the charging / discharging circuit 8 in FIG. 8 also vary, and signals other than the basic signal, for example, noise signals. Must be taken into consideration. Therefore, in FIG. 8, in order to absorb the variation of the stepping motor 2 and the variation of the charge / discharge circuit 8, the outputs E13a ₁ , E13a ₂ , E13b ₁ , E1 of the applied voltage subtraction circuit 13 are absorbed.
The voltage level of 3b ₂ is adjusted by the output amplifier circuit 3 to become E3a ₁ , E3a ₂ , E3b ₁ and E3b ₂ , respectively, and then noise is removed by the signal processing circuit 4, for example, by a low pass filter or a band pass filter. signal _{E4a 1, E4a 2, E4b 1} , E4b 2 , and the input to the subtraction circuit 5. E13a ₁ and E1 in FIG.
3a ₂ , E13b ₁ , E13b ₂ , and E3a ₁ , E3a ₂ , E3b ₁ , E3b ₂ and E in FIGS. 10 (b) and 10 (c).
Waveforms of 4a ₁ , E4a ₂ , E4b ₁ and E4b ₂ are shown respectively.

In this way, in the subtraction calculation circuit 5 of FIG. 8, the outputs E4a ₁ , E4a ₂ , E4 of the signal processing circuit 4 are output.
b ₁ and E4b ₂ and outputs E8A ₁ and E8 of the charge / discharge circuit 8.
A _2, E8B _1, E8B ₂ and is subtraction, A ₁ of the main winding, A _2, B _1, current iA ₁ flowing through the B _2, iA _2, i
B _1, induced component Ea ₁ by _{iB 2, Ea 2, Eb 1} , Eb 2
And the applied voltage components VA ₁ , VA ₂ , VB ₁ and VB ₂ can be removed.

FIG. 11 shows the output of the charging / discharging circuit 8 in FIG.
Force waveform E8A₁, E8A₂, E8B₁, E8B₂And subtraction
Output waveform E5A of the arithmetic circuit 5₁, E5A₂, E5B₁, E
5B ₂Indicates. Then, the output E5 of the subtraction calculation circuit 5
A₁, E5A₂, E5B₁, E5B₂But to the waveform shaping circuit 6
Is entered.

Next, the waveform shaping circuit 6 in FIG.
And explain. First, the position correlation as shown in FIG.
Induced voltage E5A₁, E5A₂, E5B₁, E5B₂Wave
When input to the shape shaping circuit 6, the waveform shaping circuit 6
First, in the comparator, as shown in 11 (b),
Each is converted into a pulse waveform by the reference voltage. COMPARE
The waveform pulse-converted by the computer is shown in the first embodiment.
E56A of FIG. 5 (a) ₁, E56A₂, E56B₁, E5
6B₂Is. Therefore, the waveform shaping circuit in FIG.
The outputs of 6 and the diagnostic circuit 7 are similar to those of the first embodiment.
Needless to say.

As described above, according to the second embodiment, the stepping motor 2 operates only by supplying the power supply and one input signal, and without providing the detection winding in addition to the main winding of the motor, In addition, the rotation signal of the rotor 2R can be detected without using a large-capacity external component, and it is possible to diagnose whether or not the motor is rotating normally, and to perform self-correction operation even in the case of abnormality. it can. Needless to say, even if the charge / discharge circuit 8 is replaced with a digital filter, the same operation is performed.

A sectional view of a stepping motor equipped with the control device of the above embodiment is shown in FIG. 12, in which 15 is a motor shaft, 16 is a bearing, 17 is a rotor magnet, and 18 is a stator. , 19 is a printed circuit board with a circuit of this control device, and 20 is a motor case.

[0050]

As is apparent from the above embodiments, according to the present invention, the number of command signals applied to the stepping motor to be controlled can be reduced, and the rotation signal of the stepping motor to be controlled can be used as an encoder, potentiometer, or the like. Detection can be performed without using a separate sensor or an external component having a relatively large current capacity such as a transformer. For this reason, not only is it advantageous in terms of price, but it is possible to obtain the functional effect that it leads to miniaturization, weight reduction, and simplification of all devices, and is independent of unnecessary hysteresis characteristics in the sensor. Further, since the output amplifier circuit is used as the waveform processing means, it is possible to flexibly deal with variations due to the motor, variations due to the applied voltage and current, and the like.

Therefore, when the control device for a stepping motor of the present invention is used in, for example, a suspension control system for an automobile, it is possible to prevent the motor from going out of step and losing the balance of the vehicle body and falling into a dangerous state. , You can expect an excellent effect in terms of safety. others,
Similar effects can be expected when used in many automobile fields such as electronically controlled four-wheel steering systems, power steering systems, engine control systems, transmission systems, and antilock brake systems.

Further, the use in the field of information equipment such as paper feed control of a printer, and further in the field of home electric appliances such as air conditioner equipment and video equipment also has the effect of reducing the size, weight and simplification of the equipment. It is possible to realize an excellent stepping motor control device.

[Brief description of drawings]

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

FIG. 2 is an excitation timing chart of the main winding of the stepping motor.

3A is an output waveform diagram of a detection winding in the first embodiment of the present invention, FIG. 3B is an output waveform diagram of an output amplifier circuit in the same embodiment, and FIG. 3C is an output waveform of a signal processing circuit in the same embodiment. Figure

FIG. 4A is an output waveform diagram of a charge / discharge circuit in the first embodiment of the present invention. FIG. 4B is an output waveform diagram of a subtraction calculation circuit in the same embodiment.

5A is an output waveform diagram of a comparator existing inside the waveform shaping circuit according to the first and second embodiments of the present invention. FIG. 5B is an output waveform diagram of the waveform shaping circuit according to the embodiment. c) Block diagram of the waveform shaping circuit in the embodiment

FIG. 6 (a) is an output waveform diagram of the waveform shaping circuit and the diagnostic circuit in the first and second embodiments of the present invention when the motor is normally rotating in the normal direction. Output waveform diagrams of the waveform shaping circuit and the diagnostic circuit in the same embodiment in the case of normal rotation in the reverse direction (c) Output waveform diagram of the waveform shaping circuit and diagnostic circuit when the motor is abnormal (d) The motor is abnormal Waveform shaping circuit and other output waveform diagram of diagnostic circuit

FIG. 7A is an input / output relationship diagram of a diagnostic circuit according to the first and second embodiments of the present invention. FIG. 7B is a block diagram of the diagnostic circuit according to the same embodiment.

FIG. 8 is a block diagram of a stepping motor control device according to a second embodiment of the present invention.

9A is an output waveform diagram of a main winding in the second embodiment of the present invention, FIG. 9B is a waveform diagram of an applied voltage component in the same embodiment, and FIG. 9C is an output waveform of an applied voltage subtraction circuit in the same embodiment. Figure

FIG. 10A is an output waveform diagram of an applied voltage subtraction circuit in the second embodiment of the present invention. FIG. 10B is an output waveform diagram of an output amplifier circuit in the same embodiment. FIG. 10C is an output of the signal processing circuit in the same embodiment. Waveform diagram

FIG. 11 (a) is an output waveform diagram of the charge / discharge circuit in the second embodiment of the present invention. (B) is an output waveform diagram of the subtraction arithmetic circuit in the same embodiment.

FIG. 12 is a sectional view of a stepping motor having a control device according to the present invention.

13A is a block diagram of a conventional stepping motor control device, and FIG. 13B is an output characteristic diagram of a potentiometer in the same device.

[Explanation of symbols]

1 rotation detection circuit 2 stepping motor 2R rotor 3 output amplification circuit 4 signal processing circuit 5 subtraction calculation circuit 6 waveform shaping circuit 7 diagnostic circuit 8 charging / discharging circuit 9 distribution circuit 9a control circuit 11 constant voltage circuit 12 power transistor circuit 13 applied voltage Subtraction circuit A ₁ , A ₂ , B ₁ , B ₂ Main winding a, b Detection winding

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[Procedure amendment]

[Submission date] November 18, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Figure 3

[Correction method] Change

[Correction content]

FIG. 3 is an output waveform diagram of the detection winding and the output amplifier circuit according to the first embodiment of the present invention.

Claims (3)

[Claims] 1. A detection winding of at least one phase is provided in a main winding wound around a stator of a stepping motor, and an induced voltage of a rotor output from the detection winding is output by an amplifier circuit and signal processing. A control device for a stepping motor, which is detected by a circuit, a charge / discharge circuit, a subtraction operation circuit, a waveform shaping circuit, a diagnostic circuit, and a control circuit to determine the rotation state of the stepping motor and to perform a self-correction operation even in the case of an abnormality. 2. The stepping motor control device according to claim 1, further comprising an applied voltage subtraction circuit for subtracting an applied voltage to the stepping motor from an induced output voltage of the main winding without providing a detection winding. 3. A distribution circuit for distributing an exciting current to the main winding,
A power transistor circuit that operates according to the output signal of the distribution circuit and a voltage / current that operates the distribution circuit, the output amplification circuit, the signal processing circuit, the charge / discharge circuit, the subtraction calculation circuit, the waveform shaping circuit, the diagnostic circuit, and the control circuit. 3. The stepping motor control device according to claim 1, further comprising a constant voltage circuit for supplying the constant voltage circuit.