JPH088783B2 - Motor control device - Google Patents

Description

The present invention relates to a motor control device for controlling the torque of a motor.

[Conventional technology]

Generally, in the case of a recording / reproducing apparatus such as a VTR, in a reel motor control system for controlling the winding and feeding operations of a tape wound on a reel, the tape feeding speed, for example, from fast forward (FF) to normal reproduction ( As in the case of (PLAY), it is necessary to perform control corresponding to different speeds. Further, it becomes necessary to wind the tape with a uniform tape tension corresponding to different winding diameters from the winding start to the winding end. For this reason, the tape winding torque control must be performed based on complicated arithmetic processing according to the above factors.

For such torque control, conventionally, a signal used for driving the reel motor is a pulse width control system, that is, a device using a control system in which the larger the torque, the larger the pulse width of the motor control input. There is.

[Problems to be solved by the invention]

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

The present invention has been made to solve the above problems, and an object of the present invention is to provide a motor control device having a short calculation processing time and a simple configuration.

[Means for solving problems]

A motor control device of the present invention is a motor control device that changes a pulse width in accordance with a drive torque value of a motor and controls the drive torque of the motor in accordance with the pulse width. Reference signal generating means for generating a pulse width signal corresponding to a predetermined torque value, and a difference between a pulse width corresponding to a torque value for driving the motor when driving the motor and a pulse width corresponding to the predetermined torque. A difference signal generating means for generating a pulse width signal and a drive signal generating means for generating a pulse width signal obtained by adding the reference pulse width and the difference pulse width in time series within a predetermined period are provided. .

[Work]

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

〔Example〕

 Hereinafter, the present invention will be described based on examples.

First, a reel motor control device based on a pulse width control system will be described with reference to FIGS.

FIG. 1 is a block diagram of a servo system in a motor control device. 1 is a frequency signal generator (hereinafter referred to as FG) for detecting the rotation cycle of a reel (not shown) rotated by a reel motor (not shown), and 2 is A counter for measuring the cycle of the FG, a gate, etc., the gate of the counter is opened by the rising edge of the FG, and the reel cycle is obtained by continuing counting until the next edge comes. The first converter 4 for converting the information on the speed (mode information) from the sequence control circuit 8 into the reel winding diameter according to the reel cycle stores the tape winding diameter information obtained from the first converter 3. A memory 5 is a switch that opens while a timer 9 described later is operating, and 6 is mode information from a sequence control circuit 8 described later and winding diameter information of the tape. Second converter for converting the torque value given to the reel control circuit 7 to be described later from the reel control circuit for driving a reel motor (not shown) by the torque value generated from the second converter 6 7, 8 VT
A sequence control circuit for giving information on the tape running speed to the first converter and the second converter depending on the running mode of R, and 9 is a timer which is triggered by a signal generated by the sequence control circuit 8 at the time of mode conversion. .

FIG. 2 is a block diagram showing the contents of the first converter 3 in FIG. 1, 10 is a multiplier, 11 is a divider, and the cycle t from the cycle measuring circuit 2 and the sequence control are shown. Mode information from the circuit 8, eg fast forward (FF),
Tape speed V is required for high-speed playback (CUE) and recording / playback (P / R). For example, the P / R at the standard speed (SP) of an 8mm VTR that records and reproduces NTSC TV signals is 14.345m.
m / sec, CUE 14.345 × n ₁ mm / sec, FF 14.34 × n ₂ mm / sec
And the multiplier 10 calculates Vt (speed time),
The divider 11 divides the V · t by a constant of 2π to obtain V · T / 2π
Is calculated to obtain the reel winding diameter R.

FIG. 3 shows information on each tape speed, that is, mode information, FF, CU
It shows the relationship between reel winding diameter and torque with E and P / R as parameters. A torque is obtained from the mode information and the winding diameter, and the reel control circuit 7 is controlled by this torque.

Now, when the VTR is in FF mode, the tape is wound on the take-up reel side at a high speed. A frequency signal is generated from FG1 by the rotation of the reel, the cycle t of the reel is measured by the cycle measuring circuit 2, and R = v · n ₂ · t / by the first converter 3.
The reel winding diameter is calculated from 2π (however, v = 14.345 mm / sec) and is stored in the memory 4 through the switch 5. The stored reel diameter and the mode information from the sequence control circuit 9 are converted into the torque as shown in FIG. 3, and the reel motor is driven via the reel control circuit 7 by this torque. As a result, the torque value is varied according to the winding diameter of the tape wound on the reel, and the tape tension is kept constant. When the mode is switched from FF to PLAY and from PLAY to CUE, the tape speed does not stabilize immediately and stabilizes after a certain transition time. Therefore, if the reel cycle is measured one by one and converted into the tape winding diameter for torque control, the cycle in the transitional period is unstable, and it becomes impossible to faithfully control the torque.

When the tape speed signal from the sequence control circuit 8 is switched, the timer 9 is activated to turn off the switching 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 is controlled by this torque. Also, after a certain time has passed, the switch 5 is turned on by the timer 9 to convert the cycle of the stable tape speed into the winding diameter and perform the reel control. Therefore, even if the tape speed changes at the time of mode transition, It can be controlled so that the tension does not change suddenly.

Further, in the present invention, a torque value-pulse width conversion circuit is further added to the second converter 6 of such a reel control system.

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

FIG. 4 (a) is a diagram showing the relationship between the torque value and the pulse width conversion, and FIG. 4 (b) is a diagram showing how the pulse width is determined according to each conventional torque. FIG. 6C 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 T ₁ ~
When varied between values up to T _2, the pulse width correspondingly varies from up to S ₁ to S _2. As shown in FIG. 4, for example, when the torque is T, the pulse width becomes S correspondingly. Conventionally, as shown in FIG. 4B, the duty of the pulse width S is changed during the pulse period t. Although the signal having the same was input to the reel motor, in the present invention, it is noted that the reference value of the torque fluctuation is T ₁ as is clear from FIG. 4 (c), and the reference value corresponding to this torque value T ₁ The pulse width, that is, S ₁ is used as a reference pulse having a predetermined pulse width and is inserted in the pulse period t, and only the difference from the pulse width S corresponding to the torque value T, that is, S-S ₁ is used as the fluctuation pulse width. , Is inserted in addition to the predetermined reference pulse width S ₁ . That is, as shown in FIG. 4 (c), a pulse width S ₁ as a reference pulse is generated in the first half of the pulse period t, for example,
And it may be as inserting the S-S ₁ which is the difference between the pulse width S ₁ of the actual pulse width S and the reference pulse to the second half.

FIG. 5 is a block diagram showing a specific example of the torque value-pulse width conversion circuit as one embodiment of the present invention, 20 is a charactor generator, 21 is a memory, 22 is a comparator, 23, 24, 25, 3
Reference numerals 0 and 31 are AND gates, 32 and 33 are OR gates, 34 is a flip-flop (hereinafter abbreviated as FF), and 41 is a counter.

FIG. 6 is a diagram in which the horizontal axis represents the torque value and the vertical axis represents the value of the corresponding pulse width. The designated value of the corresponding pulse width is stored in the charactor generator 20 for each torque value. There is.

The tape winding diameter information from the memory 4 and the mode signal from the sequence control circuit 8 are input to the charactor generator 20 as inputs. Chara Tactie Enetator 20 is RO
It is composed of M (read only memory), and corresponds to the torque value of the charactor generator 20 used for reading. By specifying this address, the specified value of the pulse width is read out. is there.

Now, assuming that the pulse width value based on the torque value T ₁ is 21/40, the charactor generator 20 outputs a specified value (10101 in decimal) as shown in FIG. The specified value of the output pulse width is input to the memory 21. 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 based on the signal indicating the pulse width.

FIG. 7 shows a configuration example of a circuit for generating the timing pulses C ₁ and C ₂ from the clock generator 35 as shown in FIG. 8. 36 is a 40-ary counter and 37 and 38 are flip-flops (FF). ). The 40-base counter 36 is the clock generator 35.
The pulse signal from is input and the pulse signal is counted. The signals output from the output terminals 20, 25 of the 40-ary counter 36 become high (H) level when the counter values reach 0, 20, 25, respectively. The FFs 37 and 38 are for generating the timing pulses C ₁ and C ₂ shown in FIG. 8, and the FF 38 inputs the signal from the 0 terminal of the 40-ary counter 36 to the set terminal S in the drawing, and the counter 36 The pulse C ₁ is generated by inputting the signal from the 20 terminal to the reset terminal R. Similarly, input the signal from 20 of the quaternary counter to the S terminal of FF37 and the signal from 25 of the 40-ary counter to the R terminal,
Forming pulse C ₂ .

FIG. 8 is a timing chart of the timing pulses C ₁ and C ₂ and a signal indicating the value of the pulse width. The pulse C ₁ is a period H for 20 clocks in which the count value of the base 40 counter 36 is 0 to 19. And the pulse C ₂ has a count value of 20 to
It becomes H level for the period of 5 clocks during 24 hours.

The specified value 21/40 of the pulse width from the charactor generator 20 is temporarily stored in the memory 21, and the data stored in the memory 21 and the data output from the counter 41 are discriminated by the comparator 22 as being large or small. I do. The counter 41
Is a hexadecimal counter and the counter 41 is the clock generator.
The clock pulse from 35 is inputted by the gate 23 only during the H level of the timing pulse C ₁ and is a hexadecimal counter for counting the inputted pulse. Memory 21
When the contents of the lower bits Q _{0 to} Q ₃ output from the counter are 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 timing pulse C ₁ is H
The value of the lower bits Q _{0 to} Q ₃ of memory 21 is 10 during the level.
If it is 15 in decimal, the values of Q _{0 to} Q ₃ are 1111 in binary, and all become H level, and if it is 0 in decimal, all become L level. The comparison result from the comparator 22 to the output of the memory 21 is input to the S terminal of the FF34 via the gates 31 and 32. If the output Q of the comparator is H level, the output from the Q terminal of FF34 is also H level. Become. The count value output from the counter 41 is the memory
When it becomes larger than 21, the output from the Q terminal of the comparator 22 becomes L
And the output signal goes through the gates 30 and 33 to FF34.
It is input to the R terminal of and resets FF34. That is FF34
The signal indicating the pulse width output from the FF 34 is at the H level during the period from the setting to the resetting. If the output from the Q ₄ terminal of the memory 21 is at the H level, the output signal is set in the FF 34 through the gates 25 and 32, and the memory 21
If the Q ₄ terminal of is at L level, the output signal is gate 24, 33
Reset FF34 via. Therefore, depending on the contents of the memory 21, the Q terminal of the FF 34 is set to the H level or the L level in accordance with the timing of the pulses C ₁ and C ₂ .

The case where the pulse width is set to 21/40 is described below with reference to FIGS. 5 and 6. First, the charactor generator 20 sets a binary value of 10101. This represents the specified value of the pulse width, and in decimal
21. This value is stored in the memory 21. Then, in the comparator 22, the value stored in the memory 21 is compared with the value counted by the counter 41 while the timing pulse C ₁ is at the H level, and when the output from the memory 21 is large, the terminal Q outputs the H level. As shown in FIG. 8, a pulse signal is output from the Q terminal of the FF 34, the H level of which corresponds to 5 clocks 0 to 4 in decimal and the L level thereafter.

Next, when the timing pulse C ₂ is at H level,
Since the output from the Q ₄ terminal of 21 is H level, gate 2
And excisional the FF34 through 5, 32, timing pulse C ₂ is L
When the level is reached, FF34 is reset. As a result, a signal having a waveform as shown in FIG. 8 is output from the Q terminal of FF34.

As described above, it is possible to generate a pulse having a resolution of 1/40 when the timing pulse C ₁ is at the H level and a pulse having a resolution of 5/40 when the timing pulse C ₂ is at the H level. The pulse width can be freely changed by changing the output from the charactor generator 20.

The signal indicating the pulse width output from the Q terminal of FF34 in FIG. 5 is input to the reel control circuit 7 in FIG.
The reel control circuit 7 controls the reel motor so that the reel motor (not shown) generates reverse torque in response to the signal indicating the pulse width shown in FIG.

〔The invention's effect〕

As described above, according to the present invention, it is possible to provide a motor control device having a short configuration and a simple configuration.

[Brief description of drawings]

FIG. 1 is a block diagram of a servo system in a motor controller as an embodiment of the present invention, FIG. 2 is a block diagram showing the contents of the first converter of FIG. 1, and FIG. 3 is a reel. Figure showing the relationship between tape winding diameter and torque value,
FIG. 4 is a diagram showing the relationship of torque value-pulse width conversion, FIG. 5 is a block diagram showing a concrete example of the torque value-pulse width conversion circuit as an embodiment of the present invention, and FIG. 6 is a torque value. Fig. 7 shows the relationship between the pulse width and the pulse width.
Block diagram showing a configuration example of a circuit for generating C ₁ and C ₂ ,
The figure is a timing chart of signals indicating the values of the timing pulses C ₁ and C ₂ and the pulse width. 20 …… Character generator 21 …… Memory 22 …… Comparator 34 …… Flip flop 41 …… Counter

Claims (1)

[Claims] 1. A motor control device for changing a pulse width according to a drive torque value of a motor and controlling a drive torque of the motor according to the pulse width, comprising: a load driven by the motor; Detecting means for detecting the driving state of the motor, torque control means for controlling the drive torque of the motor based on the output of the detecting means and speed command information, storage means for storing the output of the detecting means, and the speed command Switching means for shutting off the output of the detection means for a predetermined time when the value is changed, and supplying the detection information of the detection means before the speed command value change stored in the storage means to the torque control means. The torque control means includes a reference signal generating means for generating a reference pulse width signal corresponding to a predetermined drive torque value of the motor, and a drive torque of the motor. Difference signal generating means for generating a pulse width signal corresponding to the difference between the pulse width corresponding to the changed drive torque target value for driving the motor and the pulse width corresponding to the predetermined torque value when changing And a drive signal generating means for generating a pulse width signal by adding the reference pulse width and the pulse width of the difference in time series within a predetermined cycle.