JPH11257995A - Pulse counter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a pulse counter producing a zero-phase signal using a pulse generator having no zero-phase signal output, producing a zero-phase signal even when a pulse generator having a zero-phase signal output is used and can detect single revolution of a motor surely while eliminating the effect of noise through combination of these two zero-phase signals. SOLUTION: A pulse detector receiving an incremental pulse train being outputted from a pulse generator having no zero-phase signal output depending on the rotation of a motor generates a zero-phase signal for each revolution of the motor. Even when a pulse generator having a zero-phase signal output is used, a pulse counter 1 generates a zero-phase signal and these two zero-phase signals are compared in order to remove trouble due to noise thus detecting single revolution of the motor surely.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulse counter for detecting one rotation of a motor by a pulse train output from a pulse generator attached to a motor drive and used in accordance with the rotation of the motor. is there.

[0002]

2. Description of the Related Art In a motor driving apparatus, a means for detecting one rotation of the motor generally uses a pulse generator having a function of generating a zero-phase signal.

[0003]

However, a pulse generator for generating a zero-phase signal is expensive due to various problems. Also, it has been difficult to distinguish between a zero-phase signal and noise by a pulse counter. Furthermore, even when using a pulse generator that generates a zero-phase signal, it has not been possible to adjust the pulse width of the zero-phase signal after installation. For this reason, (a) in a bad environment, the noise penetrates violently, and noise penetrates the output of the pulse generator that generates the zero-phase signal, and the conventional pulse counter erroneously detects this. (B) In addition, when a noise filter is provided in the pulse counter for noise countermeasures, the waveform of the normal zero-phase signal is often impaired, and this also has a disadvantage that it cannot be detected by the conventional pulse counter. Was. As described above, it is not easy to provide a zero-phase signal output to the pulse generator and detect one rotation of the motor with the pulse counter. The present invention has been made in view of the above points, and an object of the present invention is to provide a pulse counter that solves these disadvantages.

[0004]

Means for achieving the object are as follows: 1) In claim 1, a two-phase pulse output from a pulse generator is input to a pulse counter, and the pulse counter outputs the two-phase pulse. A pulse counter for outputting one rotation signal of the electric motor after a logical operation, wherein the pulse counter outputs the two-phase pulse
A pulse converter for converting the phase to a phase, a rotation direction detector for detecting the forward / reverse rotation of the two-phase pulse input, and an integration counter for receiving the outputs of the pulse converter and the rotation direction detector as inputs. A detector for detecting the minimum value and the maximum value of the count value of the integrated count; a coefficient device for setting the minimum value and the maximum value of the count value; and an output of the rotation direction detector and a count value of the detector, which are coefficients. A minimum and maximum value computing unit that receives the output when the set value of the unit is reached, and an output of the computing unit to an integrating counter, and repeats counting from 0 to the maximum value and the maximum value to 0. , A zero-phase pulse generator that generates a zero-phase pulse, and a zero-phase pulse width adjuster that adjusts a pulse width output by the zero-phase pulse generator.

[0005] 2) An arithmetic unit for generating a zero-phase pulse from the pulse generator, and inputting the zero-phase pulse and the output of the zero-phase pulse generator, wherein the output of the arithmetic unit is a motor. 2. The pulse counter according to claim 1, wherein the signal is one rotation signal.

That is, a pulse detector that receives an incremental pulse train output from a pulse generator that does not have a zero-phase signal output according to the rotation of the motor generates a zero-phase signal for each rotation of the motor. In addition, even when a pulse generator having a zero-phase signal is used, a zero-phase signal is generated by a pulse counter, and the two zero-phase signals are compared to eliminate noise interference and reliably detect one rotation of the motor. Is what you do. It should be noted that the present invention also includes the use of both the mechanical incremental method and the method of the present invention. Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0007]

FIG. 1 is a block diagram showing an embodiment of a pulse counter according to claim 1 of the present invention, and FIG. 2 is an output waveform diagram of FIG. In FIG. 1, reference numeral 1 denotes a two-phase (A-phase, B-phase) output pulse generator which is used by being attached to a motor driving device. The forward / reverse rotation of the motor is detected by a two-phase pulse train output from the pulse generator. 2 is a pulse counter according to the present invention. 3 is a pulse converter for converting two pulse trains output from the pulse generator into one phase, 4 is a rotation direction detector for detecting forward / reverse rotation of the motor, 5 is an integration counter, and 6 is a counter of the integration counter. A maximum value detector for numerical values, 7 is a minimum value detector for the count value of the integrating counter, 8 is a maximum coefficient unit, 9 is a minimum coefficient unit,
10 and 11 are AND gates, 12 is an OR gate, a zero-phase pulse generator, 13 is a zero-phase pulse width adjuster, and 14 is a one-rotation signal obtained by the present invention.

In FIG. 1, a rotation direction detector 4 detects the rotation direction of a motor and sends it to an UP / DOWN input of an integration counter 5 and AND gates 10 and 11 as arithmetic units. "H" is input to the UP / DOWN input of the integrating counter 5.
When the "i" or "Low" signal is input, the integrating counter enters an up or down count mode.
The output of the pulse converter 3 is sent to the CLK input of the integration counter 5, and the integration counter 5 counts up or down by one each time a pulse is input to this CLK input. The count value of the integrating counter 5 is output from Q of the integrating counter 5 and sent to the maximum value detector 6 and the minimum value detector 7. The maximum coefficient unit 8 sets a numerical value corresponding to the number of pulses generated per rotation of the two-phase pulse generator. Normally, 0 is set in the minimum coefficient unit 9.

Next, the operation when the motor is rotating forward will be described. The rotation direction detector detects forward rotation, and this signal is sent to the UP / DOWN input of the integrating counter 5 and the AND gate 10. As a result, the integrating counter 5 performs a count-up operation, and the count value is sent to the maximum detector 6 from Q. The maximum detector 6 is a maximum coefficient unit 8
When the output of the integration counter ≤ the output Q of the integration counter 5, AND
A signal is sent to the gate 10. As a result, the AND gate 10
Sends a signal to the clear input CLR of the integrating counter 5 and the zero-phase pulse generator 12 to clear the count value of the integrating counter 5 to zero. That is, the integrating counter 5 repeats counting from 0 to the maximum value. Thus, the zero-phase pulse generator 12 generates a zero-phase pulse every time the count value of the integrating counter 5 reaches the maximum value of the maximum coefficient unit 8. The pulse width adjuster 13 extends the pulse width of the zero-phase pulse to a predetermined pulse width.

Next, when the motor reversely rotates, the integrating counter 5 performs a countdown operation based on the output of the rotation direction detector 4. The minimum detector 7 generates a zero-phase signal when the output Q of the integration counter 5 satisfies the condition of Q ≦ 0 (the output of the minimum coefficient unit 9), and sends a signal to the LOAD input of the integration counter 5. As a result, the maximum value of the integration counter 5 is preset by the maximum coefficient unit 8 connected to the preset input D. That is, the integrating counter 5 repeats the count from the maximum value to 0, and repeats the counting from the zero-phase pulse generator 12
Thus, a signal of one rotation of the motor can be obtained. Thus, one rotation of the motor can be detected when the motor is rotating forward or reverse. FIG. 1 shows the logic I
Needless to say, it can be realized by a CPU other than the configuration by C.

Next, a pulse counter according to a second aspect will be described. FIG. 3 is a block diagram showing one embodiment, and FIG. 4 is a waveform diagram of each part in FIG. In FIG. 3, even when the pulse generator has a zero-phase signal output (Z-phase), the zero-phase signal is reliably generated in combination with the zero-phase signal by the pulse counter according to the present invention. In FIG. 3, reference numerals 1 to 14 are the same as those in FIG. 15 is a noise filter, 16 is an AND
The gate 17 is a one-turn signal obtained according to the present invention. FIG. 3 shows an example in which the zero-phase signal of the pulse generator 1 is compared with the zero-phase signal obtained by the pulse detector to reliably detect one rotation of the motor.

[0009]

As described above, according to the present invention, even if a pulse generator having no zero-phase signal output is used, a zero-phase signal can be obtained by a pulse counter as described above. Can be detected. Even when a pulse generator having a zero-phase signal output is used, a pulse counter generates a zero-phase signal, and by combining these two zero-phase signals, the influence of noise is eliminated to ensure one rotation of the motor. Can be detected, which is extremely useful in practice.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the first aspect of the present invention.

FIG. 2 is an example of an output waveform diagram of the pulse generator of FIG. 1;

FIG. 3 is a block diagram showing an embodiment according to claim 2 of the present invention.

FIG. 4 is a waveform diagram of each part in FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pulse counter 3 Pulse converter 4 Rotation direction detector 5 Integration counter 6 Maximum value detector 7 Minimum value detector 8 Maximum coefficient unit 9 Minimum coefficient unit 10 AND gate 11 AND gate 12 OR gate 13 Pulse width adjuster 14 1 Rotation signal 15 Noise filter 16 AND gate 17 One rotation signal

Claims (2)

[Claims] 1. A pulse counter for counting a pulse signal output from an incremental type pulse generator attached to a rotating device such as an electric motor, wherein a two-phase pulse output from the pulse generator is supplied to a pulse counter. A pulse counter for inputting and outputting one rotation signal of the electric motor after a logical operation by the pulse counter, wherein the pulse counter converts the two-phase pulse input into one phase; A rotation direction detector for detecting the forward / reverse rotation of the electric motor based on the two-phase pulse input, an integration counter receiving the outputs of the pulse converter and the rotation direction detector, and a minimum value of the integration count A detector for detecting the maximum value and the maximum value, a coefficient unit for setting the minimum value and the maximum value of the count value,
A minimum value and maximum value computing unit which receives the output of the rotation direction detector and the output when the count value of the detector reaches a set value of the coefficient unit, and an output of the computing unit to an integrating counter. , 0-maximum value, and a zero-phase pulse generator that generates a zero-phase pulse while repeating counting from a maximum value to 0, and a zero-phase pulse width adjuster that adjusts a pulse width output by the zero-phase pulse generator A pulse counter characterized by comprising: 2. An arithmetic unit for generating a zero-phase pulse from the pulse generator and inputting the zero-phase pulse and the output of the zero-phase pulse generator, wherein the output of the arithmetic unit is used as a one-rotation signal of a motor. The pulse counter according to claim 1.