JPH04355687A - Motor controller - Google Patents

Abstract

PURPOSE:To obtain a motor controller employing a software serve system disturbance estimation observer requiring no hardware such as A/D converters or D/A converters. CONSTITUTION:Angular speed OMEGA of a motor is calculated based on an FG signal fed from the FG section 13 of the motor. A speed error signal Bn of the motor is then determined based on thus calculated angular speed OMEGA and added to an estimation value Cn fed from a disturbance estimation observer 7 and the sum An is fed to the disturbance estimation observer 7. Consequently, hardwares such as A/D converters or D/A converters not required, resulting in simplification of the constitution and enhancement of control performance.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor control device that monitors the operation of a motor, such as disturbance torque, and controls the speed of the motor.

0002

2. Description of the Related Art In devices such as VTRs, it is important to improve motor control technology in order to ensure improved reliability and miniaturize the device. In particular, the performance of the motor used to drive the drum and capstan of a VTR greatly affects the image quality and sound quality, and in recent years there has been an increasing demand for VTR motor control.

Conventionally, the performance of motor control in a VTR has been improved through digitalization and software. However, in this direction of investigation, there are certain limits or obstacles to improving control rigidity against wow and flutter, disturbance suppression, motor variation, etc.

In order to eliminate such limitations or obstacles, a configuration has previously been proposed in which modern control theory is used in VTR capstan control and a disturbance elimination loop is provided using a disturbance estimation observer. VTR
"Robust Control of Capstan Motor", Journal of the Television Society, vol. 44, No. 11, pp. 1618-1
621 (1990), see Nagasawa et al. ).

FIG. 16 shows the configuration of a conventional motor control device configured using a disturbance estimation observer. The device shown in this figure assumes that the motor to be controlled is a drum motor or a capstan motor of a VTR.

The device shown in this figure uses PWM (Pulse Width Modulation) to control the motor (1).
n) It is a controlling device. In other words, the speed error signal is P
A PWM converter (2) for converting into WM signals is provided. A low pass filter (hereinafter referred to as LPF) (3), an amplifier (4), and a motor drive amplifier (hereinafter referred to as MDA) (5) are provided in this order after the PWM converter (2). LPF (3) is a filter that removes the PWM carrier frequency component from the PWM signal, and its output is an analog voltage. The amplifier (4) amplifies the analog voltage output from the LPF (3) and supplies it to the MDA (5). The MDA (5) converts the analog voltage amplified by the amplifier (4) into a current to be supplied to the motor (1), that is, a drive current I.

The drive current I is supplied to the motor (1) and the disturbance estimation observer (7) via the adder (6). The motor (1) is driven by the output of the adder (6),
Rotates with angular velocity ω. The disturbance estimation observer (7) takes in the output of the adder (6) and also takes in the angular velocity ω of the motor (1) as an electrical signal. The disturbance estimation observer (7) generates an observer calculation signal according to these inputs, and feeds it back to the addition section (6). Since the adder (6) adds this observer calculation signal to the output of the MDA (5), the drive current I actually supplied to the motor (1) and the disturbance estimation observer (7) is ) is a value that reflects the observer calculation signal that is the output. That is, a feedback loop related to disturbance estimation is formed.

Further, in this conventional example, a speed error calculation section (8) is provided. This speed error calculation section (8
) takes in an electrical signal representing the angular velocity ω, generates a velocity error signal, and supplies it to the PWM converter (2). Since the PWM signal is generated according to this speed error signal, it can be said that the speed error calculation section (8) forms a feedback loop related to speed control of the motor (1).

[0009] Actually, the phase control system (motor (1)
) is provided, but it is omitted here for the purpose of simplifying the explanation.

A block diagram of the apparatus shown in this figure is shown in FIG. 17. In this figure, the motor (1) is represented as a current-torque converter (9) and a torque-rotation converter (10). The current-torque converter (9) is a block showing a part of the motor (1) that converts the drive current I, which is the output of the adder (6), into the drive torque TM, and the torque-rotation converter (10). ) is a block showing a part that converts torque TM into angular velocity ω. Therefore, the transfer function of the current-torque converter (9) is the torque constant KT, and the transfer function of the torque-rotation converter (10) is the inertia J of the motor (1) and the viscous braking coefficient D.
This is expressed as a first-order lag function 1/(Js+D).

However, in this figure, an adder (1) is installed between the current-torque converter (9) and the torque-rotation converter (10).
1) is depicted. This adder (11) is a block that models the addition of disturbance torque TG to torque TM, which is the output of the current-torque converter (9). Therefore, strictly speaking, what is actually input to the torque-rotation converter (10) is not the torque TM, but the torque TM+disturbance torque TG.

[0012] Also, in this figure, a PWM converter (
The transfer function of 2) is expressed as PWM conversion gain KPWM, and the transfer function of LPF (3) is expressed as HLPF(s). Furthermore, an amplifier (4) and an MDA (5)
The composite transfer function of block (12
) (hereinafter referred to as the amplification section).

Next, the speed error calculation section (8) is depicted in this figure as an FG section (13), a speed detection section (14), and a speed system coefficient section (15). The FG section (13) converts the angular velocity ω into an electrical signal and generates an FG (Frequency) signal.
generator ) signal. The FG signal is a signal having rising/falling edges synchronized with the rotation of the motor (1). In this figure, the number of FG pulses per motor rotation (number of rises or falls)
is shown as KFG. The FG signal is taken into the speed detection section (14). The speed detection section (14) has a transfer function HF(s), detects the rotation speed ω based on the FG signal, and supplies it to the speed system coefficient section (15). The speed system coefficient section (15) multiplies the output of the speed detection section (14) by the speed system coefficient KF to generate a speed control signal and supplies it to the PWM converter (2).

On the other hand, the disturbance estimation observer (7) includes a configuration in which the drive current I is multiplied by KT·g. In FIG. 17, this configuration includes a voltage converter (16), an A/D converter (17), a current converter (18), and a multiplier (19).
It consists of A voltage converter (16) multiplies the drive current I by a conversion gain R and converts it into a voltage signal. A/D
The converter (17) A/D converts this voltage signal and outputs it as a digital value. The conversion gain of the A/D converter (17) is FAD. The current converter (18) multiplies the output of the A/D converter (17) by a coefficient α and supplies the result to the multiplier (19). Here, the coefficient α=1/(R·FAD). Therefore, the output of the current converter (18) has a conversion gain of 1
This corresponds to the drive current I converted into a digital value. A multiplier (19) multiplies this digital value by KT·g. Here, KT is the torque constant as mentioned above,
By multiplying this by this digital value, the torque TM, which is the output of the current-torque converter (9), is estimated. g is a constant that determines the disturbance suppression band by the disturbance estimation observer (7). The output of the multiplier (19) is sent to the adder (
20).

[0015] In the disturbance estimation observer (7), the angular velocity ω is taken in by the multipliers (21) and (22).
It is. Note that in reality, it is common to have a configuration in which the angular velocity ω is detected based on the FG signal rather than being directly fetched, but in order to simplify the diagram, it is depicted as being directly fetched. The multiplier (21) adds J・to the angular velocity ω.
The multiplier (22) multiplies g2 by J.g. The output of the multiplier (21) is added to the output of the multiplier (19) in an adder (20), and is supplied to a subtracter (24) via a first-order delay element (23). First-order lag element (2
3) is a digital filter with a transfer function of 1/(s+g), so the output of the adder (20) is delayed by a time corresponding to g. The subtractor (24) has
The output of the multiplier (22) is also supplied, and the subtracter (24)
) subtracts the output of the multiplier (22) from the output of the multiplier (23). The output of the subtractor (24) is TG^ in this figure.
It is shown in

TG^ corresponds to the estimated value of the disturbance torque TG. This is based on Figure 3 and equations (3) to (
5) (showing the form of Gopinath's minimum-dimensional observer). That is, this conventional disturbance estimation observer (7) is an example configured as a minimum dimension observer.

Disturbance torque T which is the output of the subtractor (24)
The estimated value TG^ of G is calculated by the multiplier (25), the voltage converter (25), and the voltage converter (25).
6), is sequentially supplied to the D/A converter (27) and the current converter (28). The multiplier (25) multiplies the estimated value TG^ by a conversion gain of 1/KT and supplies the result to the voltage converter (26). The voltage converter (26) multiplies the signal supplied from the voltage converter (26) by a conversion gain β to convert it into a voltage signal, and supplies the voltage signal to the D/A converter (27). D/A
A converter (27) performs D/A conversion on this voltage signal. The conversion gain is FDA. The current converter (28) is a D/
The A-converted voltage signal is multiplied by 1/R, converted into a current signal, and supplied to the adder (6). Here, the voltage converter (2
The conversion gain β in 6) is R/FDA.

This conventional device has the configuration described above. Next, the operation of this conventional example will be explained.

In this conventional example, the FG signal corresponding to the angular velocity ω of the motor (1) is generated in the FG section (13), and the speed detection section (14) detects the rise or fall of the FG signal and detects the rise or fall of the FG signal. Detects a time interval as a period. The speed system coefficient section (15) outputs a speed error signal having a value corresponding to this cycle, and PWM control of the motor (1) is performed based on this signal so that the motor (1) rotates at a predetermined angular velocity.

Here, when the drive current I and the angular velocity ω are taken into the disturbance estimation observer (7), the disturbance estimation observer (7) calculates the estimated value TG^ based on these, and
An observer calculation signal having a value corresponding to the estimated value TG^ is output to the adder (6). The adder (6) is an amplifier (12)
The output of the motor (1) and the observer calculation signal are added, and the motor (1) is controlled to rotate at a predetermined angular velocity based on the addition result. As a result of this control, the motor (1) rotates so that the disturbance torque TG applied to the motor (1) is canceled out.

[0021]

[Problem to be Solved by the Invention] Conventionally, it has been possible to drive a motor so as to cancel out disturbance torque, but as mentioned earlier, it is necessary to make the device smaller and more reliable. It is better to implement the device using software as much as possible. In FIG. 17, the parts that can be implemented in software (that is, realized by a certain type of processor) are mainly the parts after leaving the A/D converter (17) and up to the D/A converter (27). , that is,
This is the part indicated by a broken line (29) in the figure. In other words, in order to implement the device using the software servo method, A/D conversion and D/A conversion are necessary to handle digital data.

[0022] As a result, such a requirement requires hardware for A/D conversion and D/A conversion, which has been a hindrance to software implementation. Further, the time delay caused by A/D conversion and D/A conversion acts as a time delay element of the disturbance estimation observer, causing deterioration of control performance.

The present invention has been made to solve these problems, and it is an object of the present invention to provide a motor control device that does not impede software implementation and has good control performance. In addition, by applying this device, FG
It is an object of the present invention to provide a device capable of reducing signal duty unevenness and a device with improved startup operation.

[0024]

[Means for Solving the Problems] In order to achieve such an object, claim 1 of the present invention provides a driving means for driving a motor according to a speed signal of a digital value, and a digital signal representing the rotational speed of the motor. A speed detection means outputs a value, and the motor is monitored based on the rotational speed and speed signal of the digital value output from the speed detection means, and variables such as disturbance torque and speed fluctuations applied to the motor are estimated, and the estimated variables are an observer that outputs a digital value, and a speed command means that generates a digital speed signal so that variables such as disturbance torque and speed fluctuations applied to the motor are offset based on the digital rotation speed and the output of the observer. It is characterized by being prepared.

A second aspect of the present invention provides a drive means for driving the motor in accordance with a speed signal, a speed detection means for outputting a square wave signal representing the rotational speed of the motor, and a square wave signal output from the speed detection means. A correction unit that corrects the duty unevenness contained in the motor and outputs it as a speed error, and a correction unit that monitors the motor based on the speed error and speed signal, estimates variables such as disturbance torque and speed fluctuations applied to the motor, and outputs the estimated variables. and speed command means for generating a speed signal so that variables such as disturbance torque and speed fluctuations applied to the motor are offset based on the speed error and the output of the observer.

Next, in a third aspect of the present invention, in the motor control device according to the second aspect, the correction section first calculates the average length of periods of the same value included in the square wave signal, and sequentially calculates the average length of the periods of the same value included in the square wave signal. It is characterized in that the duty unevenness is corrected by subtracting from the time length of , and adding the target length of the period.

[0027]Furthermore, claim 4 provides a driving means for driving the motor according to a speed signal, a speed detection means for detecting the rotational speed of the motor, and a rotational phase of the motor is output by integrating the rotational speed of the motor. monitors the motor based on the digital rotation speed and speed signal output from the phase detection means and the speed detection means, estimates variables such as disturbance torque applied to the motor, speed fluctuation, etc., and outputs the estimated variables. an observer, a speed command means that generates a speed signal such that variables such as disturbance torque and speed fluctuation applied to the motor are offset based on the rotational speed, rotational phase, and output of the observer; and a rotational phase detected by the phase detection means. The present invention is characterized by comprising a phase synchronization pull-in determining means for determining whether or not phase synchronization pull-in is being performed based on the result, and supplying the output of the observer to the speed command means only when the phase synchronization pull-in is being performed.

[0028] According to a fifth aspect of the present invention, in the motor control device according to the fourth aspect, the phase synchronization pull-in determining means determines that the phase synchronization pull-in has been performed after a predetermined period of time has elapsed after starting the motor. do.

[0029]

According to the first aspect of the present invention, the driving means drives the motor in accordance with a digital speed signal. The rotation speed of this motor is output as a digital value from the speed detection means. The observer monitors the motor based on the digital rotation speed and speed signal output from the speed detection means, estimates variables such as disturbance torque and speed fluctuations applied to the motor, and outputs the estimated variables as digital values. . This digital value is input to the speed command means together with the rotational speed of the digital value, and the speed command means generates a speed signal of the digital value based on these values so that variables such as disturbance torque and speed fluctuation applied to the motor are offset. . Therefore, in the present invention, there is no need to A/D convert the drive current or D/A convert the observer output. Therefore, hardware for A/D conversion and D/A conversion is not required, and deterioration in control performance due to time delay caused by the presence of this hardware is avoided. In the second aspect of the present invention, the driving means drives the motor according to the speed signal. The speed detection means outputs a square wave signal representing the rotational speed of the motor. The correction section corrects the duty unevenness included in this square wave signal and outputs it as a speed error. The observer monitors the motor based on this speed error in addition to the speed signal, estimates variables such as disturbance torque applied to the motor, speed fluctuation, etc., and outputs the estimated variables. This variable is supplied to the speed command means together with the speed error, and the speed command means generates a speed signal based on these variables so that variables such as disturbance torque and speed fluctuations applied to the motor are offset. Therefore, in this claim, even if the square wave signal has duty unevenness due to doubling or the like, this duty unevenness is corrected, and the estimation of variables such as disturbance torque becomes more accurate.

In the third aspect of the present invention, the correction section first calculates the average length of periods of the same value included in the square wave signal. The correction unit sequentially subtracts this average length from the time length of the period,
Add the target length for the relevant period. In claim 3, by correcting the duty unevenness using such a method, the variation in the duty unevenness is corrected. In a fourth aspect of the present invention, the driving means drives the motor according to the speed signal. The speed detection means detects the rotation speed of the motor. Further, the phase detection means outputs the rotational phase of the motor by integrating the rotational speed of the motor. The observer monitors the motor based on these quantities, that is, the digital rotational speed and speed signal output from the speed detection means, estimates variables such as disturbance torque applied to the motor, speed fluctuation, etc., and calculates the estimated variables. Output. The speed command means generates a speed signal based on the rotational speed, rotational phase, and output of the observer so that variables such as disturbance torque and speed fluctuations applied to the motor are offset. Then, the phase synchronization pull-in determining means determines whether phase synchronization pull-in is being performed based on the rotational phase detected by the phase detection means, and supplies the output of the observer to the speed command means only when it is being performed. Therefore, in claim 4, since the output of the observer is not reflected in the control when phase synchronization pull-in is not performed, inaccuracies in the observer output due to phase fluctuations at startup, for example, are eliminated from the control. As a result, phase synchronization is speeded up, and once phase synchronization has been achieved,
Motor rotational speed fluctuations are suppressed.

In the fifth aspect of the invention, the phase synchronization pull-in determining means determines that phase synchronization pull-in has been performed after a predetermined time has elapsed after starting the motor. This is based on the fact that it is possible to roughly predict the time until phase synchronization entrainment occurs after the orbit. With this configuration, while the effect of claim 4 is generally ensured, the configuration is simplified.

[0032]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. Note that the same components as those of the conventional example shown in FIGS. 16 and 17 are denoted by the same reference numerals, and the description thereof will be omitted.

FIG. 1 shows the configuration of a motor control device according to a first embodiment of the present invention, and FIG. 2 shows a block diagram thereof.
each is represented. As shown in FIG. 1, in this embodiment, the driving current I is not taken into the disturbance estimation observer (7), but the added value An is taken into the disturbance estimation observer (7). Furthermore, the observer calculation value Cn, which is the output of the disturbance estimation observer (7), is not fed back to the adder (6) placed in front of the motor (1) like the observer calculation signal in FIG. It is fed back to the adder (6) at the subsequent stage of the arithmetic unit (8). The addition section (6) is an MD
Rather than adding the observer control signal to the output of A (5), the speed error signal Bn and the observer calculation value Cn are added, and the added value An is sent to the disturbance estimation observer (7) in addition to the PWM converter (2). supply In addition, in FIGS. 1 and 2,
Although the FG section for supplying the angular velocity ω to the disturbance estimation observer (7) is not shown, nor is the phase control system shown, it is assumed that these actually exist.

In the block diagram shown in FIG.
The disturbance estimation observer (7) is connected to the multipliers (30) and (31).
)It is included. The multiplier (30) multiplies the addition value An by a coefficient and supplies the result to the adder (20), and the multiplier (31) multiplies the estimated value TG^ by a coefficient to obtain the observer calculation value Cn.
It is supplied to the adder (6) as

The coefficients multiplied in the multiplier (30) are KPWM.KA.KT.g. In the conventional example shown in FIG.
LPF(s)・KA・R・FAD・α・KT・g, which can be transformed into KPWM・HLPF(s)・KA・KT・g by substituting α=1/(R・FAD). Ru. In this embodiment, the cutoff frequency of the LPF (3) is set sufficiently higher than the frequency handled by the motor control system (that is, in the band handled by the disturbance estimation observer (7), HL
By setting the cutoff frequency to a value that can be regarded as PF(s)=1, significant influence on the control performance of the disturbance estimation observer (7) is avoided. That is, KPWM・HLPF(s)・KA・KT・g to HL
KPWM.KA.KT.g, excluding PF(s), is assigned to the multiplier (30).

Similarly, since the output destination of the disturbance estimation observer (7) has been changed to the stage after the velocity system coefficient section (15), the multiplication section (31) has a coefficient 1/(KPWM·K
A/KT) is given. More specifically, the coefficients of the multiplier (31) are set so that the transfer function of the feedback path from the output of the subtracter (24) to the adder (6) in the conventional example is preserved.

Next, the operation of this embodiment will be explained. FIG. 3 shows the operation of this embodiment.

In this embodiment, the operation of the speed error calculation unit (8) is in a waiting state (101) until a rising or falling edge of the FG signal output from the FG unit (13) is detected. . When an edge is detected, the time difference from the previously detected edge, that is, the period of the FG signal, is calculated, and based on this period, the speed error signal Bn is calculated as in the conventional example (102).

On the other hand, the angular velocity ω is determined by the disturbance estimation observer (7
) (103). In this embodiment as well, as in the conventional example, the means for supplying the period of the FG signal to the multipliers (21) and (22) after obtaining it is omitted from FIG. The disturbance estimation observer (7) calculates the estimated value TG^ based on the values of the angular velocity ω and the added value α, and further outputs the observer calculation value Cn (104). Here,
The operation of step (104) is the same as that of the conventional disturbance estimation observer (7), except that the multipliers (30) and (31) are modified as described above.

The observer calculation value Cn is supplied to the adder (6) and added to the speed error signal Bn (105). Therefore, An=Bn+Cn. The resulting addition value An is supplied to the PWM converter (2), and PWM control of the motor (1) is performed accordingly (1
06). At the same time, this added value An is also supplied to the multiplier (30) and used in step (104). After this, the process returns to step (101).

As described above, according to this embodiment, the same basic operations as in the conventional example can be executed, and the advantages obtained in the conventional example can still be enjoyed. Furthermore, in this embodiment, the addition value An, which is a digital value, instead of the drive current I, which is an analog value, is supplied to the disturbance estimation observer (7), and the output of the disturbance estimation observer (7) is Since the signal is a digital quantity that can be added to the speed control signal Bn without any need for A/D conversion or D/A conversion. Therefore, the device can be configured in terms of software, and there is no time delay due to A/D conversion or D/A conversion, and control performance is improved. Specifically, Figure 2
Of the parts within the broken line (29), except for the hardware part (32) represented by the two-dot chain line, it can be implemented as software.

In this embodiment, the disturbance estimation observer (7) is a minimum dimension observer, but it may be of another type, for example, a same dimension observer. Furthermore, the present invention may be applied to an observer such as a speed estimation observer instead of a disturbance estimation observer. In addition to the drum motor and capstan motor of the VTR, other types of motors may also be controlled. Furthermore, PWM
Instead of control, the motor may be controlled by a D/A conversion method or the like.

FIG. 3 shows the configuration of a second embodiment of the present invention. In this embodiment, the first embodiment is a motor (1).
In contrast to the previous configuration where the current was controlled, this configuration uses voltage control. In particular, the control method shown in this figure is a method in which a transistor that voltage-controls the motor (1) is directly driven by a PWM signal.

This embodiment uses a microcomputer (3
3). This microcomputer (33)
monitors the output of an angular velocity ω detection means (not shown), controls the speed and phase of the motor (1), and also functions as a disturbance estimation observer. Microcomputer (3
The output of 3) is a PWM signal, which is supplied to the transfer block (34).

The transfer block (34) has a transfer function Gd(
s). The transmission block (34) includes transistors (TR1), (TR2), and transistors (TR2).
base resistance (R1), base-emitter resistance (R2) of transistor (TR2), switching diode (
D), a coil (L), and a capacitor (C).

[0046] The base of the transistor (TR1) has P
WM signal is supplied. Therefore, the transistor (T
R1) is turned on and off by a PWM signal. The collector of transistor (TR1) is connected to the base of transistor (TR2), thus transistor (TR2)
It is also turned on and off by the PWM signal. The coil (L) and capacitor (C) constitute a filter that converts the switching waveform of the transistor (TR2) into direct current, and its cutoff frequency is set so that the transfer function of the filter can be approximated to 1, as in the first embodiment. It is set high enough.

In this embodiment, the microcomputer (33) functions in the same manner as in the first embodiment. Since the drive current I is determined from the PWM conversion gain KPWM and the transfer function Gd(s), the estimated value TG^ can be obtained. That is, the same effects as in the first embodiment can be obtained in this embodiment as well.

FIG. 5 is a block diagram of a motor control device according to a third embodiment of the present invention. In this embodiment, instead of taking the angular velocity ω from the torque-rotation converter (10) into the disturbance estimation observer (7), the output of the speed detector (14) is transferred to the converter (35) in the disturbance estimation observer (7). ) to the multipliers (21) and (22). In this case, the conversion gain α' of the conversion section (35) is the reciprocal of the product of the conversion gains of the FG section (13) and the speed detection section (14), that is, α'=2π/(KFG・HF(s)
). This embodiment also performs the same operation as the first embodiment and can ensure the same effects.

Further, in this embodiment, the FG section (13) has a configuration as shown in FIG. That is, it has a magnetic head (36), a threshold voltage source (37), and a waveform shaping circuit (38). It is assumed that the motor (1) is provided with a magnetization pattern (201) in advance.

The magnetic head (36) of the FG section (13) reads the magnetized pattern (201) and supplies the sine wave signal (a) to the waveform shaping circuit (38). Waveform shaping circuit (38)
In addition to the sine wave signal (a), the threshold voltage source (
A threshold voltage (b) is supplied from 37), and the waveform shaping circuit (38) compares the sine wave signal (a) with the threshold voltage (b). Then, as shown in FIG. 7, the sine wave signal (a) becomes the threshold voltage (b)
An FG signal (c) is obtained which is a square wave signal with an H value during a larger period and an L value during a smaller period. This FG signal (
c) is supplied to the speed detection section (14) and used for speed control and disturbance torque estimation.

In this example, if the threshold voltage (b) is an accurate value (b1), the result shown in FIG.
An FG signal (c) denoted as c1) is obtained. Here, the threshold voltage (b1) with an accurate value is the voltage at which such an FG signal (c1) with an H value period = T/2, an L value period = T/2, and a duty ratio of 50% is obtained. shall be said. T is the period of the sinusoidal signal (a) and therefore the FG signal (c). If such an FG signal (c1) is used, no control error will occur even if it is doubled and used.

However, such a threshold voltage (
If the threshold voltage (b2) is deviated from b1), the FG signal (c2) has a duty ratio of ≠50%. In other words, duty unevenness occurs. Even when speed detection is performed by outputting such an FG signal (c2) from the FG section (13), if speed detection is performed by detecting only the rising edge or falling edge of the FG signal (c), the period is Since T is constant, no problem arises. However, when doubling is performed, that is, when speed is detected by detecting the time between the rising edge and the falling edge, the duty unevenness is reflected in the disturbance torque estimation operation. This causes fluctuations in the rotation of the motor (1).

FIG. 8 shows a block diagram of a fourth embodiment that has been further improved with attention to such points. This embodiment has a configuration in which a correction section (39) is added to the third embodiment. The correction unit (39) is a speed detection unit (14)
It is a member that can be configured using software. Therefore, in this embodiment as well, the same effects as in the first embodiment or the third embodiment can be obtained.

A new effect obtained with this embodiment is accurate estimation of disturbance torque by correction of duty unevenness. 9 and 10 show the operation of this embodiment,
The advantages of this embodiment will be explained below through an explanation of its operation.

In this embodiment, the FG section (13) operates in the same manner as in FIGS. 6 and 7. Speed detection part (14)
performs determination (301) on the FG signal (c). This determination (301) is a step of determining whether either the rising edge or the falling edge of the FG signal (c) is input. That is, in this embodiment, a doubling operation is performed in which both a rising edge and a falling edge are input to detect a half cycle. Judgment (301
) until it is determined that an input has been made in (3).
01) is repeated.

If it is determined that the input has been made, the correction unit (39) increments the content m of the FG counter by 1 (302). The FG counter is configured in software or hardware in the processor, and is configured in a correction section (
39) is a counter used, and is initially set to "0". The content m of this FG counter indicates whether the input edge is a rising edge or a falling edge, as will be understood in the following explanation.

Next, the speed detection section (14) detects the FG signal (
The half period xm of c) is calculated (303). Correction section (39
) determines whether the correction calculation flag is "1" (304). The correction calculation flag is a flag indicating whether correction calculation is being performed or not, and its initial value is "1". Therefore, it is "1" immediately after the start of operation, and step (305
).

In step (305), the correction section (
39) performs an even/odd judgment on the content m of the FG counter. Since the initial value is 0, if m is an even number, it is immediately after a rising edge is input, and if m is an odd number, it is immediately after a falling edge is input. If the number is odd, the time difference between the rising edge input this time and the falling edge input last time is the step. Conversely, if the number is even, the time difference between the falling edge input this time and the rising edge input last time is the step. (303) half period xm
is sought after. Therefore, if the number is odd in step (305), the current half cycle xm is the half cycle of the L value of the FG signal (c), and if the number is even, the current half cycle xm is the half cycle of the FG signal (c). c) is the half cycle of the H value.

In this embodiment, the correction section (39) separately totals the half cycle of the L value and the half cycle of the H value. That is, if it is determined that the number is even, step (30
6) is executed, and if it is determined to be an odd number, step (
307) is executed. In step (306), xm is added to xh, and in step (307), xm is added to xl. However, it is assumed that xh and xl are initially set to "0".

These steps (306) and (307)
After execution of , determination (308) is executed. That is, the correction unit (39) determines whether addition has been performed a predetermined number of times (n times). If the result of this determination is that it has not been performed, the process returns to step (301) and the calculations described above are repeated.

[0061] If it is determined in step (308) that such an operation has been repeated n times,
The correction unit (39) executes step (309). At this time, xm when the content m of the FG counter is an even number is x
h, and xm in the case of an odd number is accumulated in xl. In step (309), xH=xh
/n xL=xl/n is calculated. It can be understood that xH and xL are the average values of the half cycle of the H value and the L value, respectively. After this, the correction unit (39) sets the correction flag to "1" (
310). The correction flag is initially set to "0" and is a flag indicating whether xH and xL are calculated.

Next, we move on to the operation shown in FIG. The correction unit (39) determines whether the correction flag is "1" (311). In this case, since the correction flag is "1", the process moves to step (312). The correction unit (39) performs an even/odd determination of the content m of the correction counter in step (312). If the number is even, the process moves to step (313), and if the number is odd, the process moves to step (314).

In step (313), X=xm−xH
+x0, but in step (314), X=xm-xL+
x0 is calculated by the correction unit (39). Here, x0 is an offset value and represents the true half cycle of the FG signal (c). Therefore, X obtained in this manner is a correction value obtained by correcting the duty unevenness from the detected half cycle xm. After that, the correction unit (39) sets the correction calculation flag to "0" and ends the correction calculation (31
5).

Subsequently, the speed system coefficient section (15) calculates the speed error (316), the disturbance estimation observer (7) estimates the disturbance torque TG (317), and the addition section (6)
) adds the speed error signal Bn and the observer calculation value Cn (318), and the added value Cn is output as a PWM signal by the PWM converter (2) (319).

After this, the process returns to step (301). Thereafter, the operations up to step (303) are similar to those described above, but since the correction calculation flag is "0" in step (304), the process branches to step (311). Furthermore, since the correction flag is already set to "1", the process moves to step (312). Note that if the correction flag is "0", the process moves to step (316).

In this way, in this embodiment, even when the edge of the FG signal (c) is detected by doubling,
More accurate disturbance torque estimation by correcting duty unevenness,
As a result, control of the motor (1) can be realized. Furthermore, since the average value is calculated and used for correction, there is no delay in calculation time.

Note that the duty unevenness correction may be performed using other methods, and the disturbance estimation observer (7) may be, for example, a same-dimensional observer instead of the minimum dimension observer, or a speed estimation observer or the like may be used instead of the disturbance estimation observer (7). May be used. Needless to say, the present invention is not limited to capstan motors and the like.

Next, a fifth embodiment of the present invention will be described. FIG. 11 is a block diagram of this embodiment.

In this embodiment, the configuration of the phase control system, which was omitted in the conventional example and each embodiment described above, is also shown. In other words, the torque-rotation converter (
an integral element (40) that converts the angular velocity ω of the motor (1) into a phase by integrating the output of the integral element (10);
A phase detector (41) that detects the rotational phase of the motor (1) from the output of the motor (40) is shown. Note that in the figure, HP(s) is the transfer function of the phase detector (41). The output of the phase detector (41) is supplied to the adder (6), thereby configuring a feedback loop related to phase control.

Furthermore, in FIG. 11, the disturbance torque TG
The adder (11) related to addition is omitted, and the amplifier unit (12), which is a block representing the gain of both the amplifier (4) and the motor drive lamp (5), is replaced by the transition amplifier unit (42).
and (43). Amplification section (42)
The gain of the amplifier section (43) is KAMP, and the gain of the amplifier section (43) is KMD.
It is expressed as A. Further, the added value An output from the adder (6) is sent to the multiplier (30) via a delay device (44).
is input. The delay device (44) is a delay device that delays the addition value An by one sampling period TF.

In this embodiment, the phase control system operates as follows. In the speed control system mentioned earlier,
The FG section (13) rotates the motor (1) according to the rotation of the motor (1).
The FG signal corresponding to the rotation speed of motor (1) was generated, but in the phase control system, P
One pulse of the G (Pulse Generator) signal is generated, and the time difference from the reference phase is measured. This measurement is performed by an integral element (40), and subsequently the rotational phase of the motor (1) is detected by a phase detector (41). This rotational transfer is supplied to the PWM converter (2) via the adder (6) and contributes to the generation of the PWM signal.

As described above, according to this embodiment, not only speed control but also phase control is performed, so that the motor (
1) rotational speed fluctuations will be suppressed.

Furthermore, since the disturbance estimation observer (7) is provided, fluctuations in the rotational speed of the motor (1) caused by the disturbance torque TG are suppressed. Furthermore, A/D conversion and D/
Since there is no need for A conversion, this embodiment can achieve the same effects as the first embodiment and the like.

FIG. 12 shows the configuration of a motor control device according to a sixth embodiment of the present invention. This figure is a block diagram, and the same omissions as in FIG. 11 are made. This embodiment is different from the fifth embodiment shown in FIG. 11 in that a phase synchronization pull-in determining means (45) is added.
Further, a changeover switch (46) that is turned on and off by the phase synchronization pull-in determining means (45) is connected to the multiplier (31).
The difference is that it is provided between the and adder (6). This embodiment is a further improvement of the fifth embodiment shown in FIG. 11, thereby making it possible to perform phase synchronization pull-in early during a transient response such as when starting a motor. That is, during a transient response such as when starting the motor, the output of the phase detector (41) fluctuates greatly, and the speed command value fluctuates greatly, resulting in overflow in the calculation process of the disturbance estimation observer (7) and disturbance torque TG. Inaccurate estimation or the like may occur, resulting in an inappropriate speed command value, which may cause problems such as delaying simultaneous phase pull-in. In this embodiment, when the motor (1) is started, under the control of the phase synchronization pull-in determining means (40), the estimation value Cn by the disturbance estimation observer (7) is cut off from being supplied to the addition unit (6). It is something to do. FIG. 13 shows the flow of operation of this embodiment. In addition, speed control,
Since the phase control and disturbance torque TG estimation operations are the same as those described above, details will be omitted here.

The apparatus of this embodiment does not perform speed detection or phase detection until an edge of the FG signal or an edge of the TG signal is input as the motor (1) rotates. FG
When the edge of the signal is input (401), step (4
The process moves to operations 05) to (410), and then moves to step (402). Also, if the edge of the PG signal is input while the edge of the FG signal is not input (4
02), executes the operations of steps (403) and (404), and returns to the FG signal edge input waiting state (401)
Return to

In step (403), phase detection is performed by the phase detector (41), and from the detection result N
P is output from the phase detector (41). The phase synchronization pull-in determination means (45) determines whether phase synchronization pull-in is achieved based on this phase detection result NP (4
04).

On the other hand, if it is determined in step (401) that an edge of the FG signal has been input, steps (405) to (410) are executed. Step (40
In step 5), the speed detection section (14) detects the speed and outputs NF as a result. The adder (6) adds the speed detection result NF, which is the output of the speed detector (14), and the phase detection result NP, which is the output of the phase detector (41), and sends the addition result N to the PWM converter ( 2) Output to (4
06). At this time, the phase synchronization pull-in determination means (45) has determined whether phase synchronization pull-in has been performed in the previous step (404). Step (4
After 06), the operation branches depending on the result of this determination (4
07), the calculation result NO (corresponding to the estimated value Cn) of the disturbance estimation observer (7) is sent to the adder (6) via the changeover switch (46) only when phase synchronization is being performed.
) (408), and the calculation result by the disturbance estimation observer (7) is added to the addition result N (40
9). That is, the phase synchronization pull-in determining means (45)
Based on the phase detection result NP, it is determined whether phase locking is performed or not, and only when it is performed, the changeover switch (46) is turned on, and the calculation result NO by the disturbance estimation observer (7) is added to the addition unit (6). supply to.

In this way, immediately after the calculation result NO of the disturbance estimation observer (7) is added to N, or when phase synchronization has not yet been performed and the changeover switch (46) is turned off, step ( 410) is executed. What is shown in step (410) is (N) PWM conversion operations by the PWM converter (2), and as a result, PWM control of the motor (1) is executed.

As described above, according to this embodiment, the disturbance estimation observer (
Since the speed control and phase control are performed using the output of 7), the phase synchronization pull-in does not become slow during a transient response such as when starting the motor (1), and also prevents disturbances. Disturbance speed fluctuations of the motor (1) due to torque TG can be suppressed.

FIG. 14 shows the configuration of a motor control device according to a seventh embodiment of the present invention. This embodiment further simplifies the configuration of the sixth embodiment shown in FIG.
This is an attempt to obtain the same effect as the embodiment more economically. That is, as clearly shown in FIG. 14, a timer (47) is provided in place of the phase synchronization pull-in determining means (45). This timer (47) is a timer that switches the changeover switch (46) from off to on after a certain period of time has elapsed since the motor (1) was started. Therefore, the operation of this embodiment shown in FIG. 15 is also different from the operation of the sixth embodiment shown in FIG. 13 in that step (404) is omitted and step (407) is replaced with step (411). . In other words, in this embodiment, the disturbance estimation observer is activated only when it can be considered that a certain period of time has elapsed during the activation of the motor (1) as a result of the operation of the timer (47), regardless of whether phase synchronization pull-in is performed or not. The calculation result NO of (7) is applied to the adder (6). Therefore, according to this embodiment, the effects obtained by the sixth embodiment can be realized with a simpler configuration.

[0081] In this embodiment, the motor (1)
The starting point of the timer (47) was set as the starting point of the timer (47).
For example, other transition times such as mode transition between normal play and special play such as speed search may be used as the reference. Further, the motor is not limited to the drum motor of a VTR, but may be a capstan motor or other other motor.

[0082]

[Effect of the invention] As explained above, claim 1 of the present invention
According to A.
/D conversion, D/A conversion, etc. are no longer required, resulting in a simplified and economical configuration by omitting hardware, and improved control performance by preventing time delays caused by A/D conversion, etc. .

Furthermore, according to the second aspect of the present invention, since the duty unevenness included in the square wave signal representing the rotational speed of the motor is corrected, the estimation of variables such as disturbance torque becomes more accurate.

According to claim 3, since the average value of the rotational frequency of the motor is calculated and the duty unevenness is corrected using this average value, it is possible to prevent the occurrence of a delay due to the calculation time in correction and to correct the duty without unevenness. Effects such as speed detection become possible can be obtained.

According to claim 4, since the output of the observer is used for control only when phase synchronization pull-in is performed, rotational speed fluctuations are not reflected in estimation of disturbance torque, etc. during transient response such as when starting a motor. In this way, errors can be prevented from occurring.

According to claim 5, since the phase synchronization pull-in determining means in claim 4 is a timer, the effect according to claim 4 can be obtained with a simple configuration.

[Brief explanation of the drawing]

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

FIG. 2 is a block diagram showing the configuration of a motor control device according to a first embodiment.

FIG. 3 is a flowchart showing the flow of operations of the motor control device according to the first embodiment.

FIG. 4 is a circuit diagram showing the configuration of a motor control device according to a second embodiment.

FIG. 5 is a block diagram showing the configuration of a motor control device according to a third embodiment.

FIG. 6 is a diagram showing the configuration and operation diagram of the FG section.

FIG. 7 is a diagram showing a waveform of an FG signal.

FIG. 8 is a block diagram showing the configuration of a motor control device according to a fourth embodiment.

FIG. 9 is a flowchart showing part of the operation of the motor control device according to the fourth embodiment.

FIG. 10 is a flowchart showing part of the operation of the motor control device according to the fourth embodiment.

FIG. 11 is a block diagram showing the configuration of a motor control device according to a fifth embodiment.

FIG. 12 is a block diagram showing the configuration of a motor control device according to a sixth embodiment.

FIG. 13 is a flowchart showing the operation of the motor control device according to the sixth embodiment.

FIG. 14 is a block diagram showing the configuration of a motor control device according to a seventh embodiment.

FIG. 15 is a flowchart showing the flow of operations of a motor control device according to a seventh embodiment.

FIG. 16 is a diagram showing the configuration of a motor control device according to a conventional example.

FIG. 17 is a block diagram showing the configuration of a conventional example.

[Explanation of symbols]

(1) Motor (2) PWM converter (6) Adder (7) Disturbance estimation observer (8) Speed error calculation unit (9) Current-torque converter (10) Torque-rotation converter (13) FG unit ( 14) Speed detection section (20) Adder (21), (22) Multiplication section (23) First-order lag element (24) Subtractor (29) Software section (30), (31) Multiplication section (33) Microcomputer (36) Magnetic head (37) Threshold voltage source (38) Waveform shaping circuit (39) Correction section (40) Integral element (41) Phase detector (45) Phase synchronization pull-in determination means (46) Changeover switch (47) Timer I Drive current ω Motor angular velocity An Added value Bn Speed member signal Cn Observer calculation value (a) Sine wave signal (b), (b1), (b2) Threshold voltage (c), (c1), (c2) FG signal xH,
xL Average value NP Phase detection result NF Speed detection result N Addition result NO Observer calculation result

Claims (5)

[Claims] 1. A drive means for driving a motor according to a speed signal of a digital value, a speed detection means for outputting a digital value representing the rotational speed of the motor, and a rotational speed and a rotational speed of the digital value output from the speed detection means. There is an observer that monitors the motor based on the speed signal, estimates variables such as disturbance torque applied to the motor, speed fluctuation, etc., and outputs the estimated variables as a digital value. A motor control device comprising speed command means for generating a speed signal of a digital value so that variables such as applied disturbance torque and speed fluctuation are canceled out. 2. Driving means for driving the motor in accordance with a speed signal, speed detection means for outputting a square wave signal representing the rotational speed of the motor, and duty unevenness included in the square wave signal output from the speed detection means. a correction unit that corrects and outputs it as a speed error, an observer that monitors the motor based on the speed error and speed signal, estimates variables such as disturbance torque applied to the motor, speed fluctuation, etc., and outputs the estimated variables; A motor control device comprising: speed command means for generating a speed signal such that variables such as disturbance torque and speed fluctuations applied to the motor are offset based on an error and an output of an observer. 3. The motor control device according to claim 2, wherein the correction section first calculates the average length of periods of the same value included in the square wave signal, and sequentially subtracts this average length from the time length of the period, A motor control device that corrects duty unevenness by adding a target length for the period. 4. Driving means for driving the motor according to a speed signal, speed detection means for detecting the rotational speed of the motor, and phase detection means for outputting the rotational phase of the motor by integrating the rotational speed of the motor. , an observer that monitors the motor based on the digital rotation speed and speed signal output from the speed detection means, estimates variables such as disturbance torque applied to the motor, speed fluctuation, etc., and outputs the estimated variables; , a speed command means that generates a speed signal such that variables such as disturbance torque applied to the motor and speed fluctuation are offset based on the rotational phase and the output of the observer; and a phase synchronization pull-in based on the rotational phase detected by the phase detection means. 1. A motor control device comprising: phase synchronization pull determining means for determining whether or not phase synchronization is being performed, and supplying the output of the observer to the speed command means only when it is being performed. 5. The motor control device according to claim 4, wherein the phase synchronization pull-in determination means determines that the phase synchronization pull-in has been performed after a predetermined time has elapsed after the motor is started.