JPS62141995A - Motor control unit - Google Patents

Abstract

PURPOSE:To obtain a control unit with less processing time and of simple constitution by producing the driving signal of the pulse width, based on the difference signal and reference signal, corresponding to the torque value with which the motor is driven. CONSTITUTION:The assigned value of the pulse width from a character generator 20 is once stored to a memory 21. With a comparator 22 the data stored in this memory 21 and the data outputted from a counter 41 are compared to make the discrimination which is the larger. The result of comparison is inputted into the terminal S of an FF 34 through gates 31 and 32. Suppose the output Q from the comparator is at H level, the output from the terminal Q will also be at H level. On this account, the pulse width can be changed in accordance with the period of the timing pulse C1 at H level and the period of timing pulse C2 at H level. The motor is then controlled so that the reel motor may produce counter-torque according to the signal indicating the pulse width outputted from the terminal Q of the FF 34.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a motor control device that controls the torque of a motor.

[Conventional technology]

Generally, in the case of a recording/playback device such as a VTR, the reel motor control system that controls the winding and feeding operations of the tape wound on the reel varies the tape feed speed from fast forward (FF) to normal playback. As in the case of (PLAY), it is necessary to perform control corresponding to different speeds. Furthermore, it becomes necessary to wind the tape with a uniform tape tension from the beginning to the end of the tape in response to different winding diameters. For this reason, torque control for tape winding must be performed based on complex arithmetic processing in accordance with each of the above-mentioned factors.

For such torque control, conventionally, the signal used to drive the reel motor uses a pulse width control method, that is, a control method that increases the width of the motor control input pulse as the torque increases. There is.

[M points while the invention is trying to solve]

In the conventional apparatus as described above, when determining the pulse width from the torque, arithmetic processing is performed from the beginning even for a slight change, so there is a problem that the arithmetic processing takes a lot of time.

The present invention has been made to solve these problems, and an object of the present invention is to provide a motor control device with a simple configuration that requires less calculation processing time.

[Means for solving problems]

The motor control device of the present invention includes a reference signal generating means for generating a reference signal with a pulse width corresponding to a predetermined torque value among the drive torque values of the motor, and a reference signal generating means for generating a reference signal with a pulse width corresponding to a predetermined torque value among the drive torque values of the motor, and a reference signal generating means corresponding to the torque value for driving the motor when the motor is driven. difference signal generating means for generating a pulse width difference signal corresponding to the difference between the pulse width of the reference signal and the pulse width corresponding to the predetermined torque; and a pulse that is the sum of the pulse width of the reference signal and the pulse width of the difference signal. The apparatus is equipped with a drive signal generating means for generating a drive signal with a width of 100 mm.

[For production]

With the above configuration, when the motor is driven, a drive signal having a pulse width corresponding to the torque value for driving the motor can be generated based on the difference signal and the reference signal.

〔Example〕

The present invention will be explained below based on examples.

First, a reel motor control device using a pulse width control method will be described with reference to FIGS. 1 to 4.

FIG. 1 is a block diagram of the servo system in the motor control device. 1 is a frequency signal generator (hereinafter referred to as FC) that detects the rotation period of a reel (not shown) rotated by a reel motor (not shown); 2 is a frequency signal generator (hereinafter referred to as FC); 3 is a cycle measuring circuit which is composed of a counter, a gate, etc. that measures the cycle of the FG, and the gate of the counter is opened by the rising edge of the FG, and the reel cycle is determined by continuing counting until the next edge comes. a first converter that converts speed information (mode information) from the sequence control circuit 8 into a reel diameter according to the reel cycle; 4 is the first converter;
A memory for storing tape diameter information obtained from the converter 3; 5 is a switch that is opened when a timer 9, which will be described later, is in operation; 6 is a mode information and tape diameter information from a sequence control circuit 8, which will be described later. a second converter that converts the torque value into a torque value to be applied to the reel control circuit 7, which will be described later;
7 is a reel control circuit that drives a reel motor (not shown) using the torque value generated from the second converter 6;
9 is a sequence control circuit that provides information on the running speed of the tape to the first converter and the second converter according to the running mode of the VTR, and 9 is a timer that is triggered by a signal generated by this sequence control circuit 8 when changing the mode. be.

FIG. 2 is a block diagram showing the contents of the first converter 3 in FIG. Mode information from circuit 8, e.g. fast forward (FF)
, high-speed playback (CUE), and recording/playback (P/R) tape speed V is determined. For example, the P/R at the standard speed (sp) of an 8 mm VTR that records and reproduces NTSC TV signals is 14.345 fi, /I
%C1CUE is 14.345 x ml / organ, FF is 14.345 x n2 mm / %e, multiplier 10 calculates V-t (velocity x time),
1 calculates the reel winding diameter R by dividing the V-t by a constant of 2π and calculating V-t/2π.

Figure 3 shows information on each tape speed, ie mode information, FF, C
This shows the relationship between reel winding diameter and torque using UE and P/R as parameters. The torque is determined from this mode information and the reel diameter, and the reel control circuit 7
is under control.

Now, when the VTR is in the FF mode, the tape is being wound onto the take-up reel at high speed. F'G by reel rotation
A frequency signal is generated from I, the period measuring circuit 2 measures the period of the reel, and the first converter 3 calculates R=v.
-n2・t/2π (however, v = 14.345 m/
see), the reel winding diameter is calculated and stored in the memory 4 through the switch 5.

The stored winding diameter and mode information from the sequence control circuit 9 are converted into torque as shown in FIG. 3, and this torque drives the reel motor via the reel control circuit 7. This allows the torque value to be varied and the tape tension to be constant depending on the diameter of the tape wound on the reel.

When the mode is switched from FF to PLAY and from PLAY to CUE, the tape speed does not stabilize immediately, but stabilizes after a certain transient period. Therefore, if torque control is performed by measuring the reel cycle one by one and converting it into the tape winding diameter, the torque control cannot be performed faithfully because the cycle in the transition period is unstable.

Therefore, when the tape speed signal from the sequence control circuit 8 is switched, the timer 9 is activated to turn off the changeover switch 5 and turn off the winding diameter signal from the first converter. In the memory 4, the winding diameter information obtained so far is converted into torque by the second converter, and the reel control is performed using this torque. Also, after a certain period of time has elapsed, the switch 5 is turned on by the timer 9, converting the period of stable tape speed into the winding diameter and controlling the reel, so even if the tape speed changes during mode transition, the tape tension remains unchanged. It can be controlled so that it does not change suddenly.

Furthermore, in the present invention, the second
This converter 6 further includes a torque value-pulse width conversion circuit.

A motor control device using a torque value-pulse width conversion circuit will be described below.

FIG. 4(a) is a diagram showing the relationship between torque value and pulse width conversion, and FIG. 4('b) is a diagram showing the conventional method of determining the pulse width according to each torque. FIG. 4(C) is a diagram showing how to determine the pulse width according to each torque as an embodiment of the present invention.

Now, as shown in Fig. 4(a), the torque fluctuation region is Tl~
If the pulse width varies between values up to T2, the pulse width will correspondingly vary in the range from 81 to S2. As shown in FIG. 4, for example, when the torque is T, the corresponding pulse width is S, and conventionally, as shown in FIG. The signal was input to the reel motor, but in the present invention, the reference value of torque fluctuation is T, as is clear from FIG. 4(C).
t, the middle part of the reference pulse corresponding to this torque value TI, Sl, is set as a reference pulse having a predetermined pulse width, and the pulse period is inserted within the reference pulse, and the pulse width corresponding to the torque value T is Only the difference from S, ie, S -81, is set as a variable pulse width and is inserted in addition to the predetermined reference pulse width 81. That is, as shown in FIG. 4(C), for example, a pulse width S1 as a reference pulse is generated in the first half of the pulse period t, and the difference between the actual pulse width S and the pulse width 81 of the reference pulse is generated in the second half. What is necessary is to insert the difference S-31.

FIG. 5 is a block diagram showing a specific example of a torque value-pulse width conversion circuit as an embodiment of the present invention, in which 20 is a character generator, 21 is a memory, 22 is a comparator, 23,
24, 25, 30.31 are AND gates, 32, 33 are OR gates, 34 is a flip-flop (hereinafter abbreviated as FF), and 41 is a counter.

In FIG. 6, the horizontal axis is a torque value, and the vertical axis is a diagram showing the corresponding pulse width value. For each torque value, the corresponding designated value of the pulse width is stored in the character generator 20.

The tape winding diameter information from the memory 4 and the mode signal from the sequence control circuit 8 are input to the character generator 20 as inputs. The character generator 20 is composed of a ROM (read only memory), and the address of the character generator 20 used for reading corresponds to the torque value, and by specifying this address, the specified value of the pulse width is read out. It is something.

Now, the value of the pulse width based on the torque value T1 is 21/40.
Then, the character generator 20 outputs a specified value (10101 in decimal) as shown in FIG. This output designated value of the pulse width is input into the memory 21. Also, CK, which is one input of the AND gate 23,
is a reference clock signal generated by the clock generator 35 shown in FIG. 7, and is the basis for creating the signal indicating the pulse width.

FIG. 7 shows a timing pulse C1*C! from the clock generator 35 as shown in FIG. 36 is a 40-decimal counter, 37.38
is 7 lip-flops (FF). The 40-decimal counter 36 inputs the pulse signal from the clock generator 35,
The pulse signals are counted. The signals output from the output terminals 0 and 20.25 of this 40-decimal counter 36 go high (
H) Become a level. FF37 and 38 are for creating timing pulses C1 and C2 shown in FIG.
A pulse C1 is generated by inputting a signal from the O terminal of the 40-decimal counter 36 to the set terminal S in the figure, and inputting a signal from the 20 terminal of the counter 36 to the reset terminal R. Similarly, the signal from 20 of the 40-decimal counter is input to the S terminal of FF37, and the signal from 25 of the 40-decimal counter is input to the R terminal to form pulse C2.0 Figure 8 shows the timing pulse. This is a timing chart of signals indicating the values of Cx, Cz and pulse width. Pulse C1 is at H level for a period of 20 clocks when the count value of the 40-decimal counter 36 is between O and 19, and pulse C2 is at the H level for a period of 20 clocks between 0 and 19. The value becomes H level for a period of five clocks between 20 and 240.

The specified pulse width value 21/40 from the character generator 20 is temporarily stored in the memory 21, and the memory 2
The comparator 22 determines whether the data stored in the counter 1 and the data output from the counter 41 are large or small. The counter 41 is a hexadecimal counter, and the clock pulse from the clock generator 35 is input to the counter 41 through the gate 23 only during the H level of the timing pulse C1, and the manually inputted pulses are counted.
It is a forward counter. Lower bit Q output from memory 21. -Q, is larger than the output of the counter 41, the signal output from the Q terminal of the comparator 22 becomes H level. For example, the lower bit Q of the memory 21 during the period when the timing pulse CL is at H level. -Q, is 15 in lO base, then the value of Q0 to Q3 is 1111 in binary, all H
If it is O in decimal, it becomes L level.

The comparison results from the comparator 22 with respect to the outputs of the memory 21 are inputted to the S terminal of the FF 34 via gates 31 and 32, and if the output Q of the comparator is at the H level, the output from the Q terminal of the FF 34 is also at the H level. become. When the count value output from the counter 41 becomes larger than the memory 21,
The output from the Q terminal of the comparator 22 becomes L level, and the output signal is inputted to the R terminal of the FF 34 via the gates 430 and 33, thereby resetting the FF 34. That is, from the time the FF 34 is set to the time it is reset, the signal output from the FF 34 and indicating the < las width is at H level. Further, when the output from the Q4 terminal of the memory 21 is at H level, the output signal sets the FF 34 via the gate 25.32, and when the Q4 terminal of the memory 21 is at the L level, the output signal is set at the gate 25, -. The FF 34 is reset via the port 24°33. Therefore, depending on the contents of memory 21, Q of FF34
Pulse Ct on the terminal.

It is set to H level or L level in accordance with the timing of C2.

Hereinafter, a case where the pulse width is set to a duty of 21/40 will be explained with reference to FIGS. 5 and 6.

First, in the character generator 20, it is 101 in binary.
A value of 01 is set. This represents the specified value of /Sars width and is 21 in decimal. This value is stored in memory 21. Then, in the comparator 22, the value stored in the memory 21 and the timing pulse C! is compared with the value counted by the counter 41 while the output from the memory 21 is at H level, and when the output from the memory 21 is large, the output from the terminal Q is
As shown in FIG. 8, a pulse signal is outputted from the Q terminal of the FF 34, which is at H level for five clocks from O to 4 in decimal notation and becomes L level thereafter.

Next, while the timing pulse C2 is at the H level, the output from the Q4 terminal of the memory 21 is at the H level, so the FF 34 is set via the gate 25.32, and when the timing pulse C2 becomes the L level, , reset FF34. As a result, a signal having a waveform as shown in FIG. 8 is output from the Q terminal of the FF 34.

As explained above, the resolution is 1/40 during the period when the timing pulse C1 is at the H level, and the resolution is 1/40 when the timing pulse C2 is at the H level.
It is possible to generate pulses with a resolution of 5/40 in a level period. The pulse width can be freely varied by changing the output from the character generator 20.

The signal indicating the pulse width output from the Q terminal of the FF 34 in FIG. 5 is input to the reel control circuit 7 in FIG. The illustrated reel motor is controlled so as to generate reverse torque.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to provide a motor control device with a simple configuration that requires less calculation processing time.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a servo system in a motor control device as an embodiment of the present invention, Fig. 2 is a block diagram showing the contents of the first converter in Fig. 1, and Fig. 3 is a block diagram showing the contents of the first converter in Fig. 1. Figure 4 is a diagram showing the relationship between the winding diameter of the tape and torque value, and Figure 4 is a diagram showing the relationship between torque value and pulse width conversion.
FIG. 5 is a block diagram showing a specific example of a torque value-pulse width conversion circuit as an embodiment of the present invention, FIG. 6 is a diagram showing the relationship between torque value and pulse width, and FIG. 7 is a timing pulse C1 , C2, and FIG. 8 is a timing chart of signals indicating values of timing pulses Cs, Cz and pulse widths. 20...Character generator 21.
......Memory 22...Comparator

Claims (1)

[Claims] The pulse width is changed according to the motor drive torque value,
A motor control device that controls the drive torque of a motor according to the pulse width, comprising a reference signal generating means for generating a pulse width signal corresponding to a predetermined torque value among the drive torque values of the motor; a difference signal generating means for generating a pulse width signal corresponding to a difference between a pulse width corresponding to a torque value for driving the motor and a pulse width corresponding to the predetermined torque; and a pulse width corresponding to the reference pulse width and the difference pulse width. 1. A motor control device comprising drive signal generating means for generating a pulse width signal with a pulse width of .