JP3182005B2 - Motor control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a PLL (Phase locked)
In an image forming apparatus such as a laser printer, a digital copier, and a laser facsimile, which controls a motor for writing, a motor for a scanner for a writing optical system or a motor for a drum for driving a photosensitive drum. The present invention relates to a motor control device.

[0002]

2. Description of the Related Art In recent years, laser printers, digital copiers, laser facsimile machines and the like have achieved higher speeds and higher output image densities with the dramatic progress of image forming technology, as well as downsizing. The weight reduction is progressing, and the scanner (for example, provided with a polygon mirror or a pyramidal mirror) provided in the laser writing system also tends to be faster and smaller together with the main unit. The laser writing system forms a two-dimensional image by rotating the photosensitive drum while scanning laser light in a one-dimensional direction with respect to the photosensitive drum using a mirror surface such as a holgon mirror, as described above. The speed range of the high-speed scanner motor is 5,000 to 15,000 [rpm] or 20,000 to
It is a wide range from low speed to high speed such as 40,000 [rpm]. In order to control such a motor, a motor control device using PLL control for comparing a phase of a reference clock with a frequency of a frequency generator pulse is often used. In recent models using a laser writing system, since the pixel density has been diversified, a device having a switching function has been developed.

The photoconductors of digital copiers and laser printers are always driven at a constant speed, but PLL control is usually also used in a motor control device for controlling the driving motor. This is because although the PLL control starts up and the controllability is poor for transient control such as switching of the number of revolutions due to the synchronization pull-in time, etc., if the control enters the constant speed operation in synchronization with the PLL, the speed / position is changed to the resolution of the encoder. This is because control can be performed within the range. For example, in the case of a color copying machine, highly accurate PLL control is performed using an encoder with a very high resolution in order to prevent color misregistration.

FIGS. 13 and 14 show a specific example of a conventional motor control device using PLL control. In this device, when the frequency generator 1 detects the rotation of the motor 3 and generates a signal having a frequency proportional to the number of rotations, the signal is shaped into a pulse signal by a waveform shaping circuit 2, and the phase comparator 4 The phase is compared with the signal. The reference signal is generated by dividing the output of the crystal oscillator 5 by the frequency divider 6. The output signal (phase difference signal) of the phase comparator 4 is smoothed (converted to a direct current) by a smoothing circuit 7 using an integrator, and is compensated in a predetermined low frequency band (for example, 1 to 10 Hz) by a phase compensating circuit 8. The voltage is applied to the drive circuit 9, whereby the motor 3 rotates at the reference speed. In addition,
The smoothing circuit 7 and the phase compensation circuit 8 have the circuit configuration shown in FIG. 15 or FIG. In FIG. 15, a smoothing circuit 7 and a phase compensation circuit 8 mainly include an amplifier 101 and resistors Ra ₁ to Ra ₁ .
The amplifier 101 includes Ra ₄ and capacitors Ca _{1 to} Ca _3, and a voltage Va is applied to an input terminal of the amplifier 101.
Here, the amplifier 101 uses the phase comparator 4 based on the voltage Va.
The phase difference pulse is smoothed and phase compensated, and a speed control signal is given to the motor drive circuit 9. In FIG. 16,
Smoothing circuit 7 and a phase compensating circuit 8 is configured to include a resistor Rb ₁ ~Rb ₄ and the capacitor Cb ₁ to CB ₃ the amplifier 102 mainly, the voltage Vb is applied to the input terminal of the amplifier 102. Here, the amplifier 102 smoothes and phase-compensates the phase difference pulse from the phase comparator 4 based on the voltage Vb, and supplies a speed control signal to the motor drive circuit 9.

[0005]

However, such a conventional motor control device has the following problems because the control range of the PLL control is narrow. It is difficult for a motor control device that controls a scanner motor to sufficiently cover a wide range of rotation speed.

In a motor control device that controls a photoconductor driving motor, when a load change due to a temperature change or a change over time occurs greatly, the motor control device falls out of a control region of the PLL control and cannot perform stable control. Specifically, as shown in FIG. 17, the phase difference duty of the PLL control when the motor speed is changed greatly differs depending on the environmental temperature change. This is because the load torque greatly changes depending on the environmental temperature. The wider the operating environment temperature range or the greater the load torque variation with respect to the temperature, the narrower the rotational speed range that can be controlled stably. In the example shown in FIG. 17, when the stable synchronization range of the PLL control is set to 10 to 60% by the phase difference duty, −
The rotational speed range in a temperature environment of 10 to 65 ° C is about 4,300 to 5,800
[rpm], and it can be seen that the controllable rotational speed range becomes very narrow.

The reference voltage Va of the amplifier 101 shown in FIG. 15 and the reference voltage Vb of the amplifier 102 shown in FIG.
C is formed by a resistive voltage division in an internal circuit or externally, but these may vary due to variations in manufacturing intersections or circuit power supply voltage. For example, as shown in FIG. 18, the value of the phase difference duty when the amplifier reference voltage varies from 1.4 to 1.7 V greatly differs depending on the reference voltage. Therefore, the more the amplifier reference voltage varies, the narrower the rotational speed range in which the control can be performed stably.

Therefore, the present invention secures a wide range of rotation speed by suppressing the fluctuation of the phase deviation with respect to the fluctuation of the rotation speed and the load, and secures the stability against the load fluctuation due to the temperature change and the aging change. It is an object to provide an enhanced motor control circuit.

[0009]

In order to achieve the above object, the invention according to claim 1 comprises a reference signal generating means for generating a reference signal, a speed detecting means for detecting a speed of a motor, and an output of the speed detecting means. According to the phase difference between the signal and the reference signal
A phase comparator that outputs a signal, a smoothing circuit that smoothes the output signal of the phase comparator, a phase compensation circuit that compensates for the phase of the output signal of the smoothing circuit, and the output signal that is phase compensated by the phase compensation circuit. A motor drive circuit for controlling drive, wherein the phase compensation
An amplifying circuit for amplifying the output signal of the circuit, a low pass filter for passing the variation of the low frequency band corresponding to the load torque fluctuation of the motor of the output signal of the amplification circuit,
3. An adding circuit for adding an output signal of the low-pass filter to an output signal of the phase comparator, wherein the reference signal generating means for generating a reference signal is provided. Speed detection means for detecting the speed of the motor; a phase comparator for outputting a signal corresponding to the phase difference between the output signal of the speed detection means and the reference signal; and a smoothing circuit for smoothing the output signal of the phase comparator. A phase compensation circuit for phase-compensating the output signal of the smoothing circuit; and a motor drive circuit for driving and controlling the motor with the output signal phase-compensated by the phase compensation circuit. an analog arithmetic circuit for calculating amplified based on the output signal to a predetermined arithmetic expression, a low frequency band fluctuation that corresponds to the load torque fluctuation of the motor the output signals of the operational circuit A low pass filter for passing,
4. An addition circuit for adding an output signal of the low-pass filter to an output signal of the phase comparator, wherein the reference signal generating means for generating a reference signal is provided. Speed detection means for detecting the speed of the motor; a phase comparator for outputting a signal corresponding to the phase difference between the output signal of the speed detection means and the reference signal; and a smoothing circuit for smoothing the output signal of the phase comparator. A phase compensation circuit for phase-compensating the output signal of the smoothing circuit; and a motor drive circuit for driving and controlling the motor with the output signal phase-compensated by the phase compensation circuit. The output signal of the motor is calculated and amplified based on a predetermined calculation formula to cope with the load torque fluctuation of the motor.
A digital operation circuit and a digital filter for filtering so as to pass only the variation in the low frequency band,
An adder circuit for adding an output signal that has been amplified and filtered by the digital operation circuit and a digital filter to an output signal of the phase comparator.

[0010]

According to the present invention, the output signal phase-compensated by the phase compensation circuit is amplified by the amplifier circuit, and the low-frequency band of the amplified signal passes through the low-pass filter and is input to the adder circuit. It is superimposed and added to the output signal. Therefore, even if the output signal of the phase comparator fluctuates due to the fluctuation of the motor load torque, the fluctuation is amplified and added to the phase deviation signal. Is compensated for the low-frequency component of the torque fluctuation.

According to the second aspect of the present invention, the phase-compensated output signal is amplified by the analog arithmetic circuit based on a predetermined arithmetic expression, and the low frequency band of the amplified signal passes through the low-pass filter and is added to the adder circuit. And superimposed and added to the output signal of the phase comparator. Therefore, by using the analog arithmetic circuit, the variation of the output signal of the phase comparator due to the variation of the motor load torque can be calculated by an approximate expression corresponding to the variation characteristic, and the variation is calculated and amplified by the analog arithmetic circuit. By adding to the phase deviation signal, compensation control is performed so as to minimize the fluctuation of the phase deviation.

According to the third aspect of the present invention, the phase-compensated output signal is amplified by the digital arithmetic circuit based on a predetermined arithmetic expression, and is filtered by a digital filter so as to pass through only a low frequency band, and is applied to the adder circuit. It is input and superimposed and added to the output signal of the phase comparator. Therefore, the variation of the phase deviation can be made very small, and the arithmetic expression for compensation can be made programmable, so that the system can be easily changed or the driving conditions can be easily changed.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the drawings. FIGS. 1 to 4 show an embodiment of the motor control device according to the first aspect of the present invention. First, the configuration will be described. In the present embodiment, the same components as those of the conventional example will be described using the same reference numerals.

1 and 2, a frequency generator 1 is connected to a motor 3, detects rotation of the motor 3, and generates a signal having a frequency proportional to the number of rotations. Is shaped into a pulse signal by the waveform shaping circuit 2, and the phase is compared with the reference signal by the phase comparator 4. This reference signal is generated by dividing the output of the crystal oscillator 5 by the frequency divider 6, and the phase comparator 4 uses this reference signal to correspond to the phase difference between the output pulse signal of the waveform shaping circuit 2 and the reference signal. And outputs a pulse signal having a pulse width. The output signal of the phase comparator 4 is smoothed by a smoothing circuit 7 using an integrator, phase-compensated through a phase compensating circuit 8, and then applied to a motor driving circuit 9, whereby the motor is driven. 3 rotates at the reference speed. The frequency generator 1 includes a frequency generator pattern (hereinafter, referred to as an FG pattern) provided on a printed circuit board and a framing caused by an intersection of a magnetic flux with a multi-pole magnetized magnet. Is configured to obtain the rotation speed signal of the rotor (magnet) by the electromotive force according to the right hand rule of F.
Instead of the G pattern, a Hall element or a magnetoresistive element for detecting the magnetized state of the magnet can be used. As shown in FIG. 3, the smoothing circuit 7 and the phase compensation circuit 8 mainly include an amplifier 101 composed of an OP amplifier and a resistor Ra.
_{1 to} Ra ₄ and capacitors Ca _{1 to} Ca ₃ ,
The voltage Va is applied to the input terminal of the amplifier 101.
The amplifier 101 smoothes and phase-compensates the phase difference pulse from the phase comparator 4 based on the voltage Va, and
Is given a speed control signal.

That is, the crystal oscillator 5 and the frequency divider 6 constitute reference signal generating means for generating a reference signal, and the frequency generator 1 and the waveform shaping circuit 2 constitute speed detecting means for detecting the speed of the motor 3. The phase comparator 4 compares the phase of the output signal of the detection means with the phase of the reference signal. Then, the output signal of the phase comparator 4 is smoothed by the smoothing circuit 7, the output signal of the smoothing circuit 7 is phase-compensated by the phase compensation circuit 8, and the driving of the motor 3 is controlled by the phase-compensated output signal. It has become.

On the other hand, in this embodiment, an amplifier circuit 10 for amplifying the output signal phase-compensated as described above, a low-pass filter 11 for passing a low-frequency band of the output signal of the amplifier circuit 10, and a low-pass filter And an addition circuit 12 for adding the output signal of 11 to the output signal of the phase comparator 4. As shown in FIG. 2, the amplifying circuit 10, the low-pass filter 11 and the adding circuit 12
Amplifies the output signal, only the low-frequency band is superposed on the phase deviation theta _e of the output signal of the phase comparator 4, circuitry to reduce the increase or decrease of the phase deviation theta _e, i.e., compensate for the low-frequency component of the torque fluctuation By controlling, always constant phase deviation θ
An automatic phase control circuit (hereinafter, referred to as an APC circuit) that stabilizes the control so that the PLL control operates in _e . In the block diagram of the PLL control system of the present embodiment shown in FIG.
₁ is a reference phase (target phase), θ ₂ is a feedback phase, ω is a rotational angular velocity, _TL is a disturbance torque, G _E (s) is a transfer function of a smoothing / phase compensation control unit, and G _M (s) is a motor unit. G _S (s) is the FG transfer function, G _APC (s) is the A
Transfer function, G _T the PC circuit torque - a voltage conversion constant.

FIG. 3 is a circuit diagram showing a detailed example of the APC circuit. As shown in the figure, the APC circuit includes a low-pass filter 11 constituted by a resistor R5 and a capacitor C4, an amplifier circuit 10 constituted mainly by an amplifier 103 and resistors R6 to R8, and an amplifier circuit 104 constituted by an amplifier 104. To R9
.. R12, and a speed control signal input to the motor drive circuit 9 by the amplifier circuit 10.
, And a signal corresponding to the increase or decrease of the speed control signal is directly superimposed on the phase comparison output by the adder circuit.

The APC circuit is not limited to the one shown in FIG. 3, but may be one having a different mode as shown in FIG.
The APC circuit shown in FIG. 4 has a low-pass filter 11 composed of a resistor R5 and a capacitor C4, and an amplifier circuit 10 mainly composed of an amplifier 103 and composed of resistors R6 to R8. The speed control signal input to the amplifier is amplified by the amplifier circuit 10, and a signal corresponding to the increase / decrease of the speed control signal is directly applied to the + input terminal of the amplifier 101 also serving as an addition circuit to perform control.

Next, the operation will be described. In FIG. 2, when the disturbance torque T _L increases and the motor load torque increases, the feedback phase θ ₂ is delayed with respect to the reference phase θ _1. At this time, the pulse of the phase deviation θ _e which is the output signal of the phase comparator 4 The output signal of the phase compensating circuit 8 which has increased in width and passed through the smoothing circuit 7 and the phase compensating circuit 8 is increased in voltage by an amount corresponding to the increase in the torque, and is input to the motor driving circuit 9 so that the motor 3 is driven. reference phase theta ₁ and the same cycle, that is controlled at a constant speed.

Further, the output signal of the phase compensation circuit 8 is amplified by the amplifier circuit 10, the increase or decrease of the low-frequency band only is superposed on the phase difference theta _e is the output signal of the phase comparator 4 phase deviation theta _e Thus, the control is stabilized so that the PLL control always operates with a constant phase deviation θ _e . That is, by adding the compensation element including the APC circuit to the PLL control circuit, the fluctuation of the phase deviation θ _e with respect to the increase or decrease of the motor load torque is suppressed.

As described above, in this embodiment, the output signal phase-compensated by the phase compensating circuit 8 is amplified by the amplifier circuit 10, and the low-frequency band of the amplified signal passes through the low-pass filter 11 and is added. Input to circuit 12,
Since the output signal of the phase comparator 4 is superimposed and added to the output signal, even if the output signal of the phase comparator 4 fluctuates due to the fluctuation of the motor load torque, the fluctuation is amplified and the phase deviation signal θ _e
Would be added to the low-frequency component of the torque fluctuation is compensated controlled to always suppress the variation of the phase difference theta _e a constant phase difference theta _e. Therefore, only by adding the APC circuit composed of a simple amplifier using an OP amplifier as a correction circuit, the fluctuation of the phase deviation θ _e with respect to the change of the rotation speed and the load is suppressed, and the rotation speed range is expanded to cover a wide range. The rotation speed region can be ensured, and the stability can be improved against a load change due to a temperature change or a change over time.

Further, when the APC circuit shown in FIG. 4 is used, the configuration is simpler than in the case of FIG. 3, and the setting error of the reference voltage Va of the amplifier 101 can be eliminated. The reduction (the disadvantage of the conventional example described with reference to FIG. 18) can be avoided, and a more stable effect can be obtained. FIGS. 5 to 9 show an embodiment of the motor control device according to the second aspect of the present invention. In the following embodiments, the same reference numerals are given to the same or corresponding components as those in the above-described example, and redundant description of the content will be omitted.

As shown in FIG. 5, in this embodiment,
An analog arithmetic circuit 13 for arithmetically amplifying the output signal phase-compensated by the phase compensation circuit 8 based on a predetermined arithmetic expression;
A low-pass filter 11 that passes a low-frequency band of an output signal of the analog operation circuit 13, and an addition circuit that adds an output signal of the low-pass filter 11 to an output signal of the phase comparator 4
12 are provided, and these constitute an APC circuit.

Specifically, as shown in FIG.
The C circuit includes a low-pass filter 11 composed of a resistor R25 and a capacitor C5, and an addition (subtraction) amplification circuit 13 mainly composed of an amplifier 105 and resistors R13 to R18.
1, an addition (subtraction) amplifier circuit 132 mainly composed of the amplifier 106 using R19 to R22, and R9 to R9 mainly composed of the amplifier 104.
And an addition circuit 12 using R12. The speed control signal input to the motor drive circuit 9 is converted into two addition (subtraction) amplification circuits 131 and 132 (analog operation circuits), for example, as y = ax + b. The signal according to the increase or decrease of the speed control signal is directly superimposed on the phase comparison output by the adder circuit 12. That is, the relationship between the correction addition voltage that causes a constant phase deviation with respect to the load torque and the IC control voltage for PLL control is expressed by a mathematical expression, and the mathematical expression is configured by an analog amplifier and added as an APC circuit.

The APC circuit is not limited to the one shown in FIG. 6, but may be one having a different form as shown in FIG.
The APC circuit shown in FIG. 7 includes a low-pass filter 11 composed of a resistor R25 and a capacitor C5, and an addition (subtraction) composed mainly of an amplifier 105 and resistors R13 to R18.
It has an amplification circuit 131 and an addition (subtraction) amplification circuit 132 mainly composed of the amplifier 106 and using R19 to R22.
The addition (subtraction) amplification circuits 131 and 132 of the speed control signal input to the motor drive circuit 9 are subjected to arithmetic amplification of y = ax + b, so that the signal corresponding to the increase / decrease of the speed control signal has as little variation in phase deviation as possible. As described above, the voltage is directly applied to the + input terminal of the amplifier 101 also serving as the addition circuit, and the control is performed.

As described above, in the present embodiment, the compensation of the APC circuit according to the first embodiment is a compensation based on a proportional operation, and is a simple compensation that does not always completely match the fluctuation of the phase deviation with respect to the increase or decrease of the motor load torque. contrast located in, by using the analog operation circuit 13 to the APC circuit, and the operational amplifier by the approximate expression output signal of the phase compensation circuit 8 to very close to the change of the phase deviation theta _e for increasing or decreasing the motor load torque It can be added to the phase deviation signal. Therefore, the fluctuation of the output signal of the phase comparator 4 due to the fluctuation of the motor load torque can be calculated by an approximate expression corresponding to the fluctuation characteristic, and the fluctuation is calculated and amplified by the analog operation circuit 13 to be converted into a phase deviation signal. By performing the addition, the compensation control is performed so as to effectively suppress the variation in the phase deviation, so that the PLL control in which the variation in the phase deviation is suppressed to a very small value and which is stable against a temperature environment and a change with time can be performed.

When the APC circuit shown in FIG. 7 is used, the configuration is simpler than in the case of FIG. 6, and the setting error of the reference voltage Va of the amplifier 101 can be eliminated. And a more stable effect can be obtained. Here, comparative tests were performed on the above-described embodiment according to claim 1, the present embodiment according to claim 2, and the conventional example, and the results will be described.

FIG. 8 is a graph showing the phase deviation duty of the PLL control when the rotational speed is changed in the range of 2,000 to 11,000 [rpm] in comparison with the above three examples. As is clear from this graph, in the conventional control method,
The fluctuation of the phase deviation duty with respect to the rotation speed is large,
It cannot be controlled above 10,000 [rpm]. On the other hand, in the above-described embodiment according to the first aspect, the fluctuation of the phase deviation duty is improved, and stable control up to approximately 10,000 [rpm] is possible. Further, in the present embodiment according to the second aspect, the fluctuation of the phase deviation duty is greatly improved to about half of the conventional example, and control is possible up to a range of 11,000 [rpm] or more.

FIG. 9 is a graph showing the result of comparing the phase difference duty when the temperature environment is changed to 10 to 60 ° C. As is clear from this graph, in the control method of the conventional example, the fluctuation of the phase deviation duty with respect to the load torque fluctuation due to the environmental temperature change is very large. The variation of the duty is improved, and in the present embodiment according to the second aspect, the variation is greatly improved as the variation of the phase deviation duty is suppressed to a very small value.

Although not shown, in this embodiment, the addition (subtraction) amplifier circuit of y = ax + b shown in FIGS. 6 and 7 is used.
If a squaring operation circuit using a multiplier is further added to 131 and 132, a correction operation such as y = cx ² + ax + b can be performed, and the APC adapted to the phase deviation characteristic of the control target can be performed.
By constructing a correction operation circuit of the circuit, a control system with less fluctuation of the phase deviation can be realized.

FIGS. 10 to 12 show an embodiment of the motor control device according to the third aspect of the present invention. As shown in FIG. 10, in the present embodiment, a digital operation circuit 14 that operates and amplifies the output signal of the phase compensation circuit 8, that is, the phase-compensated output signal, based on a predetermined operation expression, A digital filter 15 for passing the low frequency band of the output signal and an adding circuit 12 for adding the output signal of the digital filter 15 to the output signal of the phase comparator 4 are provided, and these constitute an APC circuit.

Specifically, as shown in FIG.
The C circuit includes an A / D converter 16, a CPU 141, a ROM 142, and a RAM 143 that constitute the digital operation circuit 14, a digital filter 15, a D / A converter 17, and an addition circuit 12 similar to the above-described example. The output signal of the phase compensation circuit 8 is sent to the CPU 14 of the digital operation circuit 14 via the A / D converter 16.
The signal is calculated and corrected by the CPU 141 so as to minimize the fluctuation of the phase deviation while exchanging data with the RAM 143 based on a predetermined calculation formula stored in the ROM 142 in advance. 15, and the low frequency band is input to the addition circuit 12 via the D / A converter 17,
The signal is directly superimposed on the phase comparison output as a signal corresponding to the increase or decrease of the speed control signal.

Note that the APC circuit of this embodiment is not limited to the one shown in FIG. 11, but may be of a different form as shown in FIG. The APC circuit shown in FIG. 12 includes an A / D converter 16, a CPU 141, a ROM 142, and a RAM 143 constituting the digital operation circuit 14, a digital filter 15, and a D / A converter 17
The control is performed by directly applying the calculated signal to the + input terminal of the amplifier 101. When this APC circuit is used, the configuration is simpler than in the case of FIG.
Since the setting error of the reference voltage Va can be removed, problems due to the variation of the reference voltage can be avoided, and a more stable effect can be obtained.

In this embodiment, the output signal phase-compensated by the phase compensation circuit 8 is amplified by the digital operation circuit 14 based on a predetermined operation expression, and is filtered by the digital filter 15 so as to pass only the low frequency band. Then, it is input to the addition circuit 12 and superimposed and added to the output signal of the phase comparator 4. Therefore, the same effect as in the above example can be obtained. In addition, since the arithmetic expression can be easily changed using a program or a memory table by digitizing the arithmetic circuit, the arithmetic expression for compensation is automatically changed by the program according to the use environment temperature, the motor driving state, and the like. This makes it possible to apply to intelligent control such as learning control, and a more stable and versatile motor control device can be obtained. Further, the motor control circuit can be shared for several types of motors and specifications.

[0035]

According to the present invention, even if the output signal of the phase comparator fluctuates due to the fluctuation of the motor load torque, the fluctuation is amplified and added to the phase deviation signal to suppress the fluctuation of the phase deviation. The low frequency component of the torque fluctuation is compensated for, so that the fluctuation of the phase deviation with respect to the rotation speed and the load fluctuation can be suppressed to secure a wide range of the rotation speed. A motor control circuit with improved stability can be provided.

According to the second aspect of the present invention, the variation of the output signal of the phase comparator due to the variation of the motor load torque is calculated and amplified by an analog arithmetic circuit using an approximate expression corresponding to the variation characteristic, and is converted to a phase deviation signal. Since the compensation control is performed so that the fluctuation of the phase deviation is very small by adding, the control range of the rotation speed can be further expanded, and a motor control circuit which is very stable against a change in temperature and a change with time can be provided.

According to the third aspect of the present invention, the variation of the output signal of the phase comparator can be finely calculated and amplified by the digital arithmetic circuit according to not only its variation characteristics but also, for example, environmental conditions and driving conditions. The fluctuation of the phase deviation can be greatly reduced by adding the deviation to the deviation signal, the rotation speed control range can be further expanded, and a motor control circuit which is very stable against temperature change and aging can be provided. .
In addition, an arithmetic expression for compensation can be programmed, and a highly versatile motor control device that can easily change the system, change driving conditions, and the like can be provided.

[Brief description of the drawings]

FIG. 1 is an overall schematic block diagram showing an embodiment of a motor control device according to the present invention.

FIG. 2 is a block diagram of the PLL control system.

FIG. 3 is a circuit diagram showing the APC circuit.

FIG. 4 is a circuit diagram showing another embodiment of the APC circuit.

FIG. 5 is an overall schematic block diagram showing an embodiment of a motor control device according to the second aspect of the present invention.

FIG. 6 is a circuit diagram showing the APC circuit.

FIG. 7 is a circuit diagram showing another embodiment of the APC circuit.

FIG. 8 is a graph showing the phase deviation duty of PLL control when the motor speed is changed within a predetermined range, in comparison with a conventional example.

FIG. 9 is a graph showing a phase difference duty when the operating temperature environment is changed, in comparison with a conventional example.

FIG. 10 is an overall schematic block diagram showing one embodiment of a motor control device according to the invention described in claim 3.

FIG. 11 is a circuit diagram showing the APC circuit.

FIG. 12 is a circuit diagram showing another embodiment of the APC circuit.

FIG. 13 is an overall schematic block diagram showing a motor control device of a conventional example.

FIG. 14 is a block diagram of the PLL control system.

FIG. 15 is a circuit diagram showing the smoothing circuit and the phase compensation circuit.

FIG. 16 is a circuit diagram showing another embodiment of the smoothing circuit and the phase compensation circuit.

FIG. 17 is a graph showing a variation characteristic of a phase deviation duty of the PLL control due to a temperature environment change.

FIG. 18 is a graph showing a variation characteristic of a phase deviation duty of the PLL control according to a change in an amplifier reference voltage.

[Explanation of symbols]

 Reference Signs List 1 frequency generator (speed detecting means) 2 waveform shaping circuit (speed detecting means) 3 motor 4 phase comparator 5 crystal oscillator (reference signal generating means) 6 frequency divider (reference signal generating means) 7 smoothing circuit 8 phase compensation circuit 9 Motor drive circuit 10 Amplification circuit 11 Low-pass filter 12 Addition circuit 13 Analog operation circuit 14 Digital operation circuit 15 Digital filter 131, 132 Addition (subtraction) amplification circuit (analog operation circuit)

Continuation of the front page (56) References JP-A-3-212183 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H02P 5/00 301

Claims (3)

(57) [Claims] 1. A reference signal generating means for generating a reference signal, a speed detecting means for detecting a speed of a motor, and a phase difference between an output signal of the speed detecting means and the reference signal.
A phase comparator that outputs the same signal, a smoothing circuit that smoothes the output signal of the phase comparator, a phase compensation circuit that compensates the phase of the output signal of the smoothing circuit, and an output signal that is phase-compensated by the phase compensation circuit. A motor control circuit comprising: a motor drive circuit that controls driving of a motor; an amplifier circuit that amplifies an output signal of the phase compensation circuit; and a load torque change of the motor among the output signals of the amplifier circuit.
A motor control device comprising: a low-pass filter that passes a variation in a low-frequency band corresponding to a motion ; and an adding circuit that adds an output signal of the low-pass filter to an output signal of the phase comparator. 2. A reference signal generating means for generating a reference signal, a speed detecting means for detecting a speed of a motor, and a phase difference between an output signal of the speed detecting means and the reference signal.
A phase comparator that outputs the same signal, a smoothing circuit that smoothes the output signal of the phase comparator, a phase compensation circuit that compensates the phase of the output signal of the smoothing circuit, and an output signal that is phase-compensated by the phase compensation circuit. the motor control circuit comprising a motor drive circuit for driving and controlling the motor, and a analog operation circuit for calculating amplified based on an output signal of the phase compensation circuit to a predetermined arithmetic expression, said one of the output signal of said arithmetic circuit Motor load torque change
A motor control device comprising: a low-pass filter that passes a variation in a low-frequency band corresponding to a motion ; and an adding circuit that adds an output signal of the low-pass filter to an output signal of the phase comparator. 3. A reference signal generating means for generating a reference signal, a speed detecting means for detecting a speed of a motor, and a phase difference between an output signal of the speed detecting means and the reference signal.
A phase comparator that outputs the same signal, a smoothing circuit that smoothes the output signal of the phase comparator, a phase compensation circuit that compensates the phase of the output signal of the smoothing circuit, and an output signal that is phase-compensated by the phase compensation circuit. A motor drive circuit for controlling the driving of the motor, comprising: amplifying and amplifying an output signal of the phase compensation circuit based on a predetermined arithmetic expression to cope with a variation in load torque of the motor. A digital operation circuit and a digital filter for filtering so as to pass only a variation in a low frequency band, and an addition for adding an output signal that has been amplified and filtered by the digital operation circuit and the digital filter to an output signal of the phase comparator. A motor control device comprising: a circuit;