JPH02197281A - Rotary phase controller - Google Patents

Abstract

PURPOSE:To prevent overshoot in phase control by disabling a phase control means for a while when the difference between the rotary phase of a rotary member provided with a means for controlling the rotary speed and the rotary phase and a reference phase comes within a predetermined range. CONSTITUTION:When a motor 1 is started, speed signal FG and phase signal PG are produced. When information SD of difference between FG and a speed reference signal RS drops below a predetermined value, a controlling circuit 12 switches a switch 15 to terminal (a) thus integrating 16 speed state information SS and adding speed correction information AS. When the difference information SD decreases furthermore, the switches 15, 18 are switched to contact (b) thus resetting the integration circuit 16 and presetting a digital filter 7. Phase control information EP is added 8, phase state information SP is fed to the integrator 16 and phase correction information AP is added 17. When phase difference information PD drops below a predetermined value, the controlling circuit 12 switches the switch 18 to the contact (a) thus turning the phase difference control OFF. By such arrangement, overshoot is prevented in phase control.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a rotational phase control device, and particularly to shortening the control pull-in time thereof.

[Prior Art] Conventionally, when configuring a rotational phase control device that controls the rotational phase of a rotating body and rotates it in synchronization with a specific reference phase, the rotational speed is controlled based on rotational speed information obtained from the rotating body. It is common to install a rotation speed control device to perform this. That is, while rotating the rotating body at a speed near a target rotational speed using a rotational speed control device, a phase difference between the rotational phase information obtained from the rotating body and reference phase information is detected, and this phase difference information is detected. It is common to control the rotational phase using a phase error signal formed based on

On the other hand, in order to perform such phase control more strongly and stably, a phase compensation circuit that mainly operates as an integrator circuit is provided, and the phase error signal is passed through this phase compensation circuit as a phase control signal to the drive system of the rotating body. It is widely practiced to supply

[Problems to be Solved by the Invention] However, the integration time constant of the phase compensation circuit may be set relatively large. In this case, there are problems in that the stability in the steady state is increased, and the response characteristic in the transient state is that the control pull-in time (lock-in time) becomes longer.

In particular, when the mixing ratio of the phase control signal to the speed control signal is increased in order to apply stronger phase control, the target phase is often approached after the rotational phase or overshoe 1 is reached, and in some cases caused a hunting phenomenon, resulting in a significantly longer lock-in time.

The present invention has been made in view of such problems, and provides a rotational phase control device that can shorten lock-in time without causing phenomena such as hunting even when strong phase control is applied. The purpose is to

[Means for Solving the Problems] With the above object in mind, the rotational phase control device of the present invention includes a speed control means for controlling the rotational speed of a rotating body, and a phase control means for controlling the rotational phase of the rotating body. and a configuration in which the phase control means is temporarily brought into a non-operating state IE in response to a phase difference between the rotational phase of the rotating body and the reference phase falling within a predetermined range.

[Operation] By configuring as described above, the phase control is deactivated when the rotational phase of the rotating body approaches the target phase, so the rotating body can rotate at the desired rotational speed, and the processing accompanying the integral processing can be performed. Since no delay occurs, there is no possibility of overshooting the rotational phase or the control target phase. Therefore, even if strong phase control is applied, no hunting phenomenon occurs, making it possible to shorten the lock-in time.

[Example] Examples of the present invention will be described below.

FIG. 1 is a diagram showing the configuration of an embodiment in which the present invention is applied to a rotary cylinder control system of a VTR, and FIG. 2 is a timing chart for explaining the operation of FIG. 1.

In Fig. 1, 1 is a tram motor that rotationally drives the VTR's rotation speed, 2 is a rotation frequency detector that generates a speed detection pulse (FG) with a frequency proportional to the rotation speed of the tram motor 1, and 3 is a rotation frequency detector that generates a speed detection pulse (FG) with a frequency proportional to the rotation speed of the tram motor 1. A rotational phase detector that generates a pulse (PG) indicating the rotational phase of the tram motor 1, 14 a speed reference signal generator that generates a speed reference signal (R3) with a frequency corresponding to a desired rotational speed, 4 FG and A speed detection circuit outputs speed control information (ES) corresponding to the speed difference between the rotational speed of the tram motor 1 and the target speed and speed difference information (SD) indicating this speed difference based on the speed reference signal; 5 is a reference phase; A phase reference signal generator 6 generates a phase reference signal (RP) indicating the phase reference signal, and 6 contains phase difference information (PD) indicating the phase difference of the PG with respect to the target phase according to the phase reference signal, and phase error information (PE) corresponding to this phase difference. ), 7 is a digital filter that acts as a phase compensation circuit, 8 is a phase control information (EP) output from the digital filter 7, the speed control information (ES), etc. are added together to generate rotation control information ( 9 is a preset data generator that generates preset data (PR) for presetting the data (Z-1 data) of each delay branch of the digital filter 7; lO is a digital analog (D/ A
) converter; 11 is a drive circuit that drives the drum motor 1;
12 is the operation of the drive circuit 11° digital filter 7 and integration circuit 16;

and a control circuit for switching each switch 15.18, 13
is the operation section of the VTR.

The speed detection circuit 4 generates speed state information (SS) indicating the magnitude of the rotational speed of the tram motor l with respect to the target speed. This information (SS) is, for example, r-IJ when the rotational speed of the tram motor l is greater than the target speed, and is "+1" when it is smaller. Similarly, the phase detection circuit 6 generates phase state information (SP) which is r+IJ when the phase of the PG is ahead of the reference phase, and is "-1" when it is behind the reference phase.

15 is a switch that is selectively connected to terminals a, b, and c and outputs speed state information SS or phase state information SP;
16 is an integrating circuit, and 17 is an adder. A switch 18 is selectively connected to the terminals a and b, and switches whether or not to supply the phase control information EP to the adder 8.

FIG. 2 is a timing chart for explaining the operation of the phase detection circuit 6 shown in FIG. 2 is used to generate digital data corresponding to a trapezoidal wave as shown in FIG. 2 TR. This data TR is sampled at the rising timing of the reference signal RC (indicated by S in the figure) and becomes phase error information PE. The purpose of this phase control is to make the timing at which the trapezoidal wave data TR reaches a predetermined value (indicated by P in the figure) and the sampling link timing S to be the same timing, and S approaches S' in the figure. Further, the circuit 6 outputs the time difference between point Po of the trapezoidal wave data TR and point S of the reference signal RC as phase difference information PD.

The operation of this embodiment will be explained below.

In the initial state, the tram motor l is stopped. The speed detection circuit 4 increases the value of the speed control information ES as the period of FG becomes longer, so the speed detection circuit 4 increases the value of the speed control information ES according to the information ES.
The value of is also large, but the control circuit 12 is larger than the drive circuit 1.
1 is in a non-energized state. Also, at this time, the control circuit 12
connects the switch 15 to the C terminal and the switch 18 to the C terminal, resets the integration circuit 16, and presets the data of each delay branch of the digital filter 7 as preset data PR.

In this state, when the operation unit 13 instructs the VTR to record or reproduce a signal, the control circuit 12 controls the drive circuit 11.
The tram motor 1 is enabled to be energized, and thereafter the tram motor 1 is driven according to the rotation control information CT.

When the control circuit 12 detects that the drum motor 1 is accelerated to near the target rotational speed after being started and has become below the absolute value of the speed difference information SD or the predetermined value THI, the circuit 12 switches the switch 15 to the C terminal. and inputs the speed state information SS to the integrating circuit 16. The output of the integrating circuit 16 is supplied to the adder 17 as speed correction information AS, and acts to make the rotational speed of the motor 1 more accurately match the target speed.

After this, the rotational speed of the drum motor l further approaches the target speed, and the absolute value of the speed difference information SD or the predetermined value TH2 (<TH
I) When the control circuit 12 detects that
Perform presets. As a result, the phase control information EP is supplied to the adder 8. Along with this, phase control information EP
Due to this action, the phase of the phase reference signal RC moves overall from the phase indicated by the solid line in FIG. 2 to the phase indicated by the dotted line with respect to PG. Additionally, phase state information SP is input to the integrating circuit 16. At this time, the output of the integrating circuit 16 is supplied to the adder 17 as phase correction information AP, and acts to more accurately match the rotational phase of the motor l with the target phase.

Here, if the phase difference between the PG and the target phase at the start of this phase control is ψ, reducing the phase difference ψ means that the rotational speed changes from the target speed due to the phase control, and this change amount ( The larger the offset amount), the faster the speed at which ψ changes, and the shorter the time it takes to reach point S or point S'. However, as mentioned above, this offset amount is determined by the ratio of the speed control information ES and the phase control information EP, and if the offset amount is made too large, that is, if the phase control is applied too strongly, the S point will pass the S' point and an overshoot will occur. It is normal to do so.

Then, when the control circuit 12 detects that the S point has entered between the points P□ and P2, that is, that the absolute value of the phase difference information PD has become less than the predetermined value TH3, the circuit 12 temporarily switches the switch 18 is connected to the C terminal, the integrating circuit 16 is reset, and the switch 15 is also connected to the C terminal to perform speed adjustment again. As a result, the rotational phase of the motor l, which has rapidly approached the target phase, can be stopped in the vicinity of the target phase, and overshoot can be reduced.

Then, the rotational speed of motor l approaches the target speed again,
When the absolute value of the speed error information SD becomes less than the predetermined value TH2, the control circuit 12 presets the digital filter 7 again, resets the integration circuit 16, and turns on the switch 15.
．． Switch 18 is connected to the b terminal to perform phase control. This results in a rapid transition to a stable phase control state.

According to the embodiment with the above-described configuration, even when the phase control information EP has a large gain with respect to the phase difference information PD and strong phase control is applied, the phase control pull-in state can be quickly achieved without causing hunting phenomena or the like. becomes. Furthermore, since the integration time constant of the digital filter 7 can be made sufficiently large in a steady state, stable phase control is possible.

In addition, by the action of the integrating circuit 16, the rotation control information CT changes until the rotational phase of the motor l completely matches the target phase, and the rotational phase of the motor can completely match the target phase.

-Once the rotational phase control reaches a steady state, the phase control is never deactivated. However, if a phase shift of more than a predetermined value occurs due to some kind of disturbance, the phase control pull-in can be similarly quickly performed by leading to a steady state through the same process as described above.

Processing of the control information of the rotation control device configured as described above can be realized by software using a processor such as a microcomputer. In particular, since the hardware that monitors the rotational control status and changes the information processing characteristics as in the above-mentioned embodiment tends to be large, it is best to use software to perform most of the processing of the control system. It's advantageous.

FIG. 3 is a flowchart illustrating the operation of the computer when the area indicated by the broken line Y in FIG. 1 is replaced by a microcomputer.

The recording or playback start/stop signal (S/
When the signal S) is input (step Sl), 0 is set in the variable ST in step S2, and the process shifts to a processing standby state in which input of each signal is waited for in steps S3 to S5. The variable ST indicates the state of this control circuit and changes from 0 to 4 from an initial state to a steady state.

In the processing standby state, when FG is input (step S
3) Speed control information ES and speed correction information AS are updated, while when PG is input (step S4) phase control information EP and phase correction information AP are updated. Then, after each update process, the output control information CTtj:E S
.

Step S16 is calculated as the sum of EP, AS, and AP.
, 527), the information CT is updated.

The following is a step-by-step explanation starting from the initial state.

When FG is input (step S3), the process goes to step S6, where the difference TE between the input times of this FG and the immediately preceding FG is calculated, and the time difference XE of the speed reference signal R3 is also calculated. These indicate the periods of FG and R3, respectively, and the speed difference information SD is given by these functions Fa (TE, XE). The speed control information ES is a function F of this speed difference information SD.
s (SD), and the speed state information SS is given by the sign of the speed difference information SD. However, when performing processing corresponding to the speed control loop filter, the speed difference information S
The speed error information SE according to D may be accumulated for a predetermined period of time, and the speed control information ES may be obtained from this accumulated information. 5T=
If it is 0, go to step S8 via step S7,
It is constantly monitored whether the absolute value SDI of the speed difference information is smaller than the predetermined value THI.

Until the rotation speed approaches the target speed, SD l > TH1, and the speed correction information AS is always O.
(step 514), and the output control information CT reflects the update of only the speed control information ES.

On the other hand, if PG is input, the process goes to step S17, where the input time of PG and the previous phase reference signal R are input.
Calculate the difference ZE from the input time of P, and if ZE≦%RP with respect to the time difference RE between adjacent phase reference signals RP, ZE
is the phase difference information PD, and if ZE>station RP, then RP-Z
Let E be phase difference information PD. In addition, phase error information PE
is given by the PD function F, (PD), and the phase state information S
P is given by the positive or negative sign of the phase difference information PD.

Since it is ST-〇 until the rotational speed approaches the target speed (step 518), the phase control information EP phase correction information A
P is set to 0 (step 525), and the output control information CT is not updated in step 326.

When the rotational speed of motor 1 approaches the target speed, SDI<THI
When it is determined that (step S8), 1 is set in ST, step S9), the speed correction information AS is reset (step 5IO), and the speed state information SS is integrated with this speed correction information AS. Go (step 515). 5T=1
In this case, as the process proceeds from step Sll to step S15, both the speed control information ES and the speed correction information AS will be updated one after another, and the rotational speed of the motor l will become closer to the target speed.

In the state of ST=1, when the rotational speed of the motor 1 approaches the target speed and lSDl<TH2 (step 5ll), 5T=2 (step 512), and the accumulated phase for a predetermined period is All error information PE is replaced with preset data PR (step 513). Then, the speed correction information AS is set to 0 (step 514), and only the speed control information ES is updated.

On the other hand, if 5T=2, from step 318 to step S1
9, the process goes to step S20, and the phase state information SP is integrated into the phase correction information AP, which has been O so far.

Then, phase error information PE (t) ~ P for a predetermined period
An operation corresponding to the digital filter in FIG. 1 is performed on E(t-n) to obtain phase control information EP (step 521). Thereafter, the above PE (t) to PE (t-n) are shifted to PE (t-1) to PE (t-n-1) (step 522), and output according to the new phase control information EP and phase correction information AP. The control information CT is updated (step 526) and phase control is executed.

At 5T=2, when the rotational phase almost matches the target phase, the absolute value IPDI of the phase difference information becomes less than a small predetermined value TH3, and this is determined (step 519), and 5T=
3, step 523), reset the speed correction information AS (step 524), and reset the phase control information EP,
Both phase correction information AP is set to 0. Then, as in the case of ST=1, only speed control and speed correction are performed.

At 5T=3, the absolute value of the speed difference information is again the predetermined value TH.
When it becomes less than 2 (step 5ll), 5T=4 and step 512), the phase error information PE (t
) ~PE (t-n) is preset, and phase control 9 phase correction processing is performed in the same way as in the case of 5T=2.

In the processing standby state, when a stop of recording or playback is given as an S/S input from the operation unit 13 (step S5).
, the output control information CT is immediately set to 0, and the rotation of the motor 1 is stopped.

Even in software processing using a microcomputer as described above, the same effect as that of the apparatus shown in FIG. 1 can be obtained.

[Effects of the Invention] As explained above, according to the present invention, there is provided a rotary phase control device that can quickly shift to a control pull-in state even when a strong phase control is applied, and that operates stably even in a steady state. can get.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of an embodiment in which the present invention is applied to a rotating cylinder control system of a VTR, FIG. 2 is a timing chart for explaining the operation of FIG. 1, and FIG. It is a flowchart showing the operation when the processing within the broken line part is performed by software processing of a microcomputer. 1 is a motor, 3 is a rotational phase detector, 5 is a reference signal generator, 6 is a phase detection circuit, 7 is a digital filter for phase compensation, 8 is an adder, 9 is a preset data generator, 1
1 is a drive circuit, 12 is a control circuit, and 18 is a phase control on/off switch.

Claims (2)

[Claims] (1) A speed control means for controlling the rotational speed of the rotary body and a phase control means for controlling the rotational phase of the rotary body, wherein the phase difference between the rotational phase of the rotary body and a reference phase is within a predetermined range. A rotational phase control device characterized in that the phase control means is temporarily deactivated in response to the input. (2) In the non-operating state, the phase control means is brought into the operating state again in response to the rotational speed falling within a predetermined range. rotational phase control device.