JPS642037B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a motor rotation control device.

For example, motors used in acoustic depth sounders are
In addition to conforming to the standards, the motor is required to have a wide rotational speed range of 1:10 or more, and to have accurate followability and responsiveness when changing speed. For this reason,
As a circuit for driving and controlling a motor, the present inventors
A reference pulse that regulates the rotational speed of the motor and a comparison pulse that corresponds to the actual rotational speed of the motor are input together, and an up/down counter is provided that performs a counting operation in response to the frequency difference between the two pulses. A motor rotation control device was provided in which the rotation speed of a remote motor was controlled by the count output outputted from an up/down counter when the frequencies of both pulses coincided.
(See No. 138220). It was confirmed that this allows the motor to be varied over a wide range of rotational speeds, and to have good followability and responsiveness even when changing speeds. The inventors further investigated the drive circuit of this motor and found that when the reference pulse and comparison pulse are continuously input to the up/down counter and the count output becomes excessively large or small, the control becomes oscillatory. The count output of this up/down counter is a carry, i.e. “1111”→“0000” or a digit decrement, i.e. “0000”.
→ "1111", the motor drive voltage changes rapidly and the rotational speed temporarily fluctuates, and it has been found that due to this, synchronous rotation according to the reference pulse may not be maintained.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to enable the motor to accurately maintain synchronous rotation according to the reference pulse at all times.

The present invention will be described in detail below based on an embodiment shown in the drawings.

FIG. 1 is a block diagram showing a motor rotation control device according to this embodiment. In the same figure, code 1 is
This is a rotation control device of the present invention. This rotation control device 1 uses a reference pulse for setting the rotation speed of the motor M.
A reference pulse train circuit 2 that shapes the waveform of P ₁ and a comparison pulse P ₂ that corresponds to the actual rotational speed of the motor M.
A comparison pulse train circuit 4 that shapes the waveform of the pulses P ₁ and P 2 , an up/down counter 6 that performs a counting operation in response to the difference in frequency between the two pulses P 1 and P ₂ , and a count output terminal Q of the up/down counter 6 converter 8, which drives the motor M based on the count output from the output terminal Q, detects the rotational speed of the motor M, and outputs a comparison pulse _P2 corresponding to the rotational speed of the motor M. Rotation speed sensor 12 and this rotation speed sensor 1
and an amplifier 14 for amplifying the comparison pulse P ₂ from P 2 . In this example, the up/down counter 6 is an 8-4-2-1 code binary counter. This rotation control device 1 further includes:
It has a count output correction section 16 which is a main part of the present invention. In this count output correction section 16, 18 compares the preset upper limit value of the pulse frequency with the count output from the count output terminal Q of this up/down counter 6, and when the two match, the upper limit is reached. 20 is a lower limit value comparison circuit that compares the count output with a lower limit value of the pulse frequency, which is also set in advance, and outputs a lower limit coincidence signal when the two match; , 24 are modified upper limit value signals and modified lower limit signals that slightly decrease and increase the upper limit value and lower limit value, respectively, in response to the upper limit coincidence signal and lower limit coincidence signal from the upper limit value and lower limit value comparison circuits 18 and 20, respectively. These are first and second fine correction circuits that output value signals. The upper limit comparison circuit 18 includes an upper limit generation circuit 18a that generates an upper limit output, and a first circuit that compares the upper limit output from this circuit 18a with the count output from the up/down counter 6.
Similarly, the lower limit value comparison circuit 20 includes a lower limit value generation circuit 18a that generates a lower limit value output, and a second comparison circuit 20b that compares the output of the circuit 18a with the count output. It is composed of. Further, this count output correction section 16 is a selection circuit that selectively outputs the corrected upper limit value signal and the corrected lower limit value signal from the first and second fine correction circuits 22 and 24 in response to the upper limit match signal and the lower limit match signal. 26 and an OR circuit 28, both of the upper limit value and lower limit value comparison circuits 18 and 20 are connected to the load terminal LO of the up-down counter 6 via this OR circuit 28, and also to the first and second The fine correction circuits 22 and 24 are connected to the preset input terminal P of the up/down counter 6 via the selection circuit 26, respectively.

Next, the rotation control operation of the motor M by the rotation control device 1 will be explained.

First, a reference pulse _P1 having a reference frequency that sets the rotational speed of the motor M is supplied to the reference pulse train circuit 2.
After the waveform is shaped by , it is input to the count up terminal UP of the up/down counter 6 at the next stage. A count value is output from the output terminal Q of the up/down counter 6 in response to the input reference pulse _P1 , and this count value is outputted from the output terminal Q of the up/down counter 6.
The signal is input to the drive unit 10 via. converter 8
When using a DC motor as motor M, D/
An A converter is used, and the DC voltage output changes in accordance with the count value of the up/down counter 6. The rotation of the motor M is controlled by this voltage output. For example, when the count value increases, the DC output voltage also increases, and the drive unit 10 increases the rotation speed of the motor M by this voltage output. Conversely, when the count value decreases, the DC output also decreases, and the drive unit 10 decreases the rotation speed of the motor M by this voltage output. In addition, when an AC motor is used as the motor M, the converter 8 is an up/down counter 6.
The AC voltage output is changed in accordance with the count value. The AC voltage can be controlled by, for example, converting the count value of the up/down counter 6 into a DC voltage using a D/A converter, and performing amplitude modulation of the AC signal using the converted DC voltage. And the drive part 1
0 rotates the AC motor according to the converted AC voltage. A drive output corresponding to the count value is generated from the drive unit 10, and the motor M is rotated by this drive output. The rotational speed of the motor M is detected by a rotational speed sensor 12. The rotation speed sensor 12 generates a comparison pulse corresponding to the above rotation speed.
Generates P ₂ . This comparison pulse P ₂ is input to the comparison pulse train circuit 4 after being amplified by the next-stage amplifier 14 . Comparison pulse train circuit 4 has comparison pulse P ₂
Shape the waveform. The comparison pulse _P2 from the comparison pulse train circuit 4 is input to the countdown terminal (DOWN) of the up/down counter 6. The up/down counter 6 performs an addition count every time a reference pulse train is applied to the count-up terminal (UP), and performs a subtraction count every time a comparison pulse is input to the count-down terminal (DOWN). Therefore, the repetition frequency of the pulse train sent out from the reference pulse train circuit 2 is the same as that of the comparison pulse train circuit 4.
, the up/down counter 6 sequentially increases the count value and sends the count value to the converter 8. Therefore, the converter 8 increases the number of rotations of the motor M by the drive unit 10 as the count value increases. The rotational speed of the motor M thus increased is detected by the rotational speed sensor 12.
The comparison pulse P ₂ detected by the rotation speed sensor 12 is fed back to the up/down counter 6 via the amplifier 14 and the comparison pulse train circuit 4. In this way the comparison pulse
Both pulses P _{1 and} P 2 are compared successively until P ₂ matches the reference pulse P ₁ in frequency, and finally the motor M
is rotated synchronously according to the reference pulse _P1 . Conversely, if the number of pulses of the reference pulse P ₁ is smaller than that of the comparison pulse P ₂ , the up/down is similar to the above.
Since the down counter 6 performs a countdown operation according to the frequency difference between the two pulses, the motor M is finally rotated synchronously following the frequency of the reference pulse _P1 .

On the other hand, the count output from the up/down counter 6 is also given to the upper limit comparison circuit 18 and the lower limit comparison circuit 20 of the count output correction section 16, and the count output is applied to the upper limit value in the circuits 18 and 20, respectively. , compared with the lower limit. When this count output matches this upper limit value, an upper limit match signal is outputted from this upper limit value comparison circuit 18 and is applied to the load terminal LO of the up/down counter 6 via the OR circuit 28. This signal is also given to the first fine correction circuit 22, and the first fine correction circuit 22 outputs a corrected upper limit value signal in response to this upper limit coincidence signal. This modified upper limit signal is then applied to the preset input terminal P of the up/down counter 6 via the selection circuit 26. Therefore, in this up/down counter 6, the load terminal
By inputting an upper limit match signal to LO and inputting a modified upper limit value signal to preset input terminal P, this modified upper limit value is preset as the count value.

Similarly, when the count output from the up/down counter 6 matches the lower limit value, the lower limit comparison circuit 20 outputs a lower limit match signal, and this signal is sent to the up/down counter 6 via the OR circuit 28. In response to this lower limit coincidence signal, a modified lower limit signal is outputted from the second fine correction circuit 24 and applied to the preset input terminal P of the counter 6 via the selection circuit 26. As a result, the corrected lower limit value is preset in the up/down counter 6 in the same manner as described above.

That is, when the count value of the up/down counter 6 reaches the upper limit value, this count value is preset to the corrected upper limit value, and when it also reaches the lower limit value, it is preset to the corrected lower limit value. Therefore, the count output of the up-down counter 6 never becomes larger than the upper limit value or smaller than the lower limit value, that is, the count output is always limited within the range from the upper limit value to the lower limit value. As a result, the drive output to the motor M is also limited within a certain range,
It is possible to prevent the control of the motor M from becoming oscillatory and becoming out of synchronization, and since the up/down counter 6 does not carry up or down, sudden changes in the count output do not occur as in the conventional case. Therefore, motor M due to change in count output.
It is also possible to prevent out of synchronization of rotation.

FIG. 2 shows another embodiment of the invention. Components common or corresponding to those in FIG. 1 are given the same reference numerals as in FIG. 1. The feature of this embodiment is that the count output correction section 1
6' is the upper limit comparison circuit 18 common to that in FIG.
In addition to the lower limit comparison circuit 20, the up terminal (UP) and down terminal (DOWN) of the up/down counter 6
The first and second gate circuits 30 and 32 are connected to the front stage of the circuit via a reference pulse train circuit 2 and a comparison pulse train circuit 4, respectively. These first and second count gate circuits 3
0 and 32 respectively input the upper limit coincidence signal and lower limit coincidence signal from the upper limit comparison circuit 18 and lower limit comparison circuit 20 as gate signals, and when the gates are closed, the up-down counter 6 is inputted.
Prevents input of reference pulse and comparison pulse to.

Therefore, when the count output from the up/down counter 6 reaches the upper limit value, the upper limit comparison circuit 18 outputs an upper limit match signal, and this signal is used as a gate signal to the first count gate circuit 30.
When the reference pulse is input to the up/down counter 6, the gate is closed and the input of the reference pulse to the up/down counter 6 is blocked.
As a result, the count output from the up/down counter 6 decreases, and this count output is limited to below the upper limit value. Similarly, when the count output from the up/down counter 6 reaches the lower limit value, the second count correction gate circuit is closed.
Since the comparison pulse input to the up/down counter 6 is blocked, the count output increases.

In this way, also in this embodiment, since the count output from the up/down counter 6 is limited to always be between the upper limit value and the lower limit value, carry-up and carry-down occur, and the count output of the counter In addition to preventing sudden changes in the count output, the motor M
The drive output to is also limited within a certain range, and the same effects as in the previous embodiment can be obtained.

As described above, according to the present invention, the preset upper and lower limits of the pulse frequency are compared with the count output of the up/down counter, and when the two match, an upper limit match signal and a lower limit signal are output. Upper limit and lower limit comparison circuits that output matching signals, and modified upper limit signals and modified lower limits that correct the upper and lower limit values in response to the upper limit matching signal and lower limit matching signal from these circuits. First and second correction circuits each outputting a value signal are provided, and the upper limit and lower limit coincidence signal output terminals of the upper limit value and lower limit value comparison circuits are connected to the upper limit and lower limit matching signal output terminals of the upper limit value and lower limit value comparison circuits through an OR circuit.
A selection of connecting the first and second correction circuits to a load terminal of a down counter and selectively outputting a corrected upper limit value signal and a corrected lower limit value signal from the correction circuit in response to the upper limit match signal and lower limit match signal. A motor rotation control device, characterized in that it is connected to a preset input terminal of the up/down counter through a circuit, a preset upper and lower limit value of a pulse frequency, and a count of the up/down counter. Comparing circuits for an upper limit value and a lower limit value are provided to respectively compare the outputs and output an upper limit match signal and a lower limit match signal when the two match. A motor rotation control device, characterized in that each gate circuit is provided for correcting the count, and the upper limit and lower limit matching signals from the upper limit value and lower limit value comparison circuits are respectively applied as gate signals to each of these gate circuits. Therefore, the count output from the up/down counter for both is always limited between the upper limit value and the lower limit value, and the motor always follows the reference pulse, so that changes in speed do not become oscillatory, so synchronous rotation is maintained accurately. It has the effect of

In addition, in the above, the converter 8 is
Although the count value of the down counter 6 has been described as being converted into a DC voltage or an AC voltage, the rotation of the motor M can also be controlled using other converters. For example, the flow time of the direct current or alternating current supplied to the motor M may be controlled. In this case, the converter 8 may convert the count value of the up/down counter 6 into a control signal for controlling the flow time of the drive current supplied from the drive unit 14 to the motor M. For example, a pulse wave whose repetition frequency or pulse width changes in accordance with the count value of the up/down counter 6 is sent out from the converter 8, and this pulse wave is used to intermittently change the flow time of the drive current. By shutting off, the shutoff interval or shutoff time may be changed in accordance with the count value.

Further, when an AC motor is used as the motor M, the frequency of the AC current may be controlled. In this case, the converter 8 may convert the count value of the up/down counter 6 into a frequency change of the alternating current signal.
For example, the converter 8 divides the reference frequency signal to generate an AC signal, and by changing the division ratio according to the count value of the up/down counter 6, the frequency of the AC signal is changed according to the count value. can be changed.

[Brief explanation of drawings]

The drawings show a motor rotation control device according to the present invention; FIG. 1 is a block diagram of this embodiment, and FIG. 2 is a block diagram of another embodiment. 1, 1'...Motor rotation control device, 6...Up-down counter, 18, 20...Upper limit value, lower limit value comparison circuit, 22, 24...First and second fine correction circuit, 26...Selection Circuit, 28, 30... 1st,
Second count correction gate circuit.

Claims (1)

[Claims] 1. An up/down system that inputs a reference pulse for setting the rotational speed of a motor and a comparison pulse corresponding to the actual rotational speed of the motor, and performs a counting operation in response to the frequency difference between the two pulses. In a motor rotation control device that includes a counter and controls the rotational speed of the motor based on the output from the up/down counter, the upper and lower limits of the pulse frequency set in advance are /Upper limit value and lower limit value comparison circuits that compare the count outputs of the down counter and output upper limit match signals and lower limit match signals, respectively, when the two match, and the upper limit match signals and lower limit match signals from these circuits. first and second correction circuits are provided which output a corrected upper limit value signal and a corrected lower limit value signal, respectively, in which the upper limit value and the lower limit value are corrected in response to the upper limit value and the lower limit value comparison circuit, and A match signal output terminal is connected to the load terminal of the up/down counter via an OR circuit, and the first and second correction circuits are configured to perform correction from the correction circuit in response to the upper limit match signal and lower limit match signal. A rotation control device for a motor, characterized in that it is connected to a preset input terminal of the up/down counter via a selection circuit that selects and outputs an upper limit value signal and a modified lower limit value signal. 2 A reference pulse for setting the motor rotation speed and a comparison pulse corresponding to the actual rotation speed of this motor are input, and an up/down counter is provided to perform a counting operation in response to the frequency difference between the two pulses. In a motor rotation control device that controls the rotational speed of the motor based on an output from a /down counter, the up/down counter counts a preset upper and lower limit of a pulse frequency, respectively. Comparing circuits for an upper limit value and a lower limit value are provided for comparing the outputs and outputting an upper limit match signal and a lower limit match signal when the two match, respectively, and a count up terminal of the up/down counter;
A motor characterized in that a gate circuit for correcting the count is provided in the preceding stage of each countdown terminal, and upper limit and lower limit coincidence signals from the upper limit value and lower limit value comparison circuits are respectively applied as gate signals to each of these gate circuits. rotation control device.