JPH10108354A - Method of judging inversive connection of motor, and motor position detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To judge the normal connection/inversive connection of a motor without using a switch. SOLUTION: A CPU 8 detects the revolution data (data on multi-revolutions) of one turn or more by A-phase pulses in the same manner as conventional one, but at this time, this observes the outer output pulses (B-phase pulses or its inversive pulses) of a line receiver 5, and if it is in high level, this judges that the motor is connected normally, and if it is in low level, this judges that the motor is connected reversely, and inverts the code of data on multi- revolutions.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention detects rotation speed data of one or more rotations from an A-phase pulse output from an absolute value encoder at power-on, and then rotates the A-phase pulse and the B-phase pulse for less than one rotation. The absolute value encoder then detects the motor reverse rotation connection identification method in a servo controller that acts as an incremental encoder.

[0002]

2. Description of the Related Art FIG. 3 is a block diagram of a motor position detecting device in a servo control device of this kind. The A-phase signal and the B-phase signal detected by the absolute value encoder 1 are subjected to noise removal or waveform shaping by the encoder input circuit 2 to become an A-phase pulse and a B-phase pulse. The reverse rotation inversion circuit 3 ′ receives the A-phase pulse and the B-phase pulse output from the encoder input circuit 2 and a signal pulled up to the power supply by the resistor 10. In a normal connection of a motor (not shown), the signal is At the high level, the A-phase pulse and the B-phase pulse are output as they are, but when the motor is connected in reverse rotation, the signal is dropped to OV and becomes the low level, and the A-phase pulse is output as it is,
The B-phase pulse is inverted and output. The pulse output from the reverse rotation inverting circuit 3 is input to the code discriminating circuit 6 via the line driver 4 and the line receiver 5. Sign determination circuit 6
Outputs a count-up sign and a pulse when the phase of the A-phase pulse is ahead of the phase of the B-phase pulse or its inverted pulse, and the phase of the A-phase pulse is greater than that of the B-phase pulse or its inverted pulse. If the phase is late, a countdown sign and pulse are output. The counter 7 counts up with an up pulse and counts down with a down pulse. The CPU 8 ′ detects rotation amount data of one or more rotations from the A-phase pulse output from the line receiver 5, and detects rotation amount data of less than one rotation based on the count value output from the counter 7. Is on (indicating that the motor is connected in reverse rotation), the sign of these rotation amount data is inverted.

[0003]

As described above, conventionally, when a switch is provided and the motor is connected in reverse rotation, the switch is turned on to inform the CPU that the motor is connected in reverse rotation, and the rotation amount data is inverted. If the control device is replaced and the connection of the connector or cable on the motor side does not match the setting of the switch, the motor will rotate in the opposite direction to the command and lead to an accident. There was a problem. SUMMARY OF THE INVENTION It is an object of the present invention to discriminate between a normal connection and a reverse rotation connection of a motor without using a switch, to prevent the machine from running out of control due to a wrong rotation position of the motor, and to detect a motor reverse rotation connection and a motor rotation amount detection. It is to provide a device.

[0004]

SUMMARY OF THE INVENTION The present invention provides a method for determining the reverse rotation connection of a motor, in which a B-phase pulse is detected during rotation data of one or more rotations from an A-phase pulse. Is output as it is, and in the case of reverse rotation connection of the motor, the output of the reverse rotation reversing circuit which reverses is observed, and it is determined whether or not the motor is reversely connected based on the level thereof. Since the reverse rotation connection setting switch is eliminated and the normal connection / reverse rotation connection of the motor is automatically determined in the CPU,
The machine does not run away due to incorrect rotation amount data. Further, the motor position detecting device of the present invention comprises: a reverse rotation inverting circuit for receiving a B-phase pulse of an absolute encoder and inverting and outputting the B-phase pulse when the motor is connected in reverse rotation; A phase determination pulse and an output pulse of the reverse rotation inverting circuit are inputted, and a code determination / counter circuit which determines a code and counts the position and a rotation of at least one rotation from the A phase pulse when power is turned on. Number data, then detect the number of revolutions less than one revolution from the count value of the code discriminating / counter circuit, observe the B-phase pulse while detecting the revolution number data of one or more revolutions, If so, a CPU for inverting the sign of the rotation speed data of one or more rotations is provided.

According to an embodiment of the present invention, a line driver and a line receiver are connected between the reverse rotation inverting circuit and the code discriminating circuit.

[0006]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a motor position detecting device according to an embodiment of the present invention, and FIG.
(2) is a diagram showing rotation amount data at the time of motor forward rotation and motor reverse rotation, respectively. In this embodiment, as compared with the embodiment of FIG. 2, the reverse connection switch 9 is eliminated, the A-phase pulse output from the encoder input circuit 2 is directly input to the line driver 4, and the reverse rotation inversion circuit 3 Only a pulse or its inverted pulse is output, and the processing of the CPU 8 is different. However, the reverse rotation inversion circuit 3 may be the same as the reverse rotation inversion circuit 3 '.

When the power is turned on, the CPU 8 operates in the same manner as in the prior art.
At least one rotation data (multi-rotation data) is detected from the phase pulse. At this time, another output pulse (B-phase pulse or its inverted pulse) of the line receiver 5 is observed, and as shown in FIG. On the other hand, if the level is high, it is determined that the motor is normally connected. If the level is low, it is determined that the motor is reversely connected, as shown in FIG. Invert the sign of the data.
In this embodiment, the line driver 4 and the receiver 5 are connected between the reverse rotation inverting circuit 3 and the sign discriminating circuit 6, but the reverse rotation inverting circuit 3 and the sign discriminating circuit 6 may be directly connected. Further, a frequency dividing circuit or the like may be provided before or after the reverse rotation inverting circuit 3.

[0008]

As described above, according to the present invention, the B-phase pulse is observed while observing the rotation speed data of one or more rotations, and the normal connection / reverse rotation connection of the motor is determined based on the level thereof. This has the effect of eliminating an accident that the machine runs away due to incorrect rotation amount data.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a motor position detecting device according to an embodiment of the present invention.

FIG. 2 is a diagram showing rotation amount data during forward rotation of the motor and reverse rotation of the motor.

FIG. 3 is a block diagram of a conventional example of a motor position detecting device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Absolute value encoder 2 Encoder input circuit 3, 3 'reverse rotation inversion circuit 4 Line driver 5 Line receiver 6 Code discrimination circuit 7 Counter 8, 8' CPU 9 Reverse connection switch 10 Pull-up resistor

Claims (3)

[Claims] When power is turned on, rotation speed data of one or more rotations is detected from an A-phase pulse output from an absolute value encoder, and then rotation speeds of less than one rotation are detected by an A-phase pulse and a B-phase pulse. Thereafter, the absolute value encoder is a motor reverse rotation connection identification method in a servo control device that functions as an incremental encoder, and while detecting rotation speed data of one or more rotations from the A-phase pulse,
The B-phase pulse is output as it is in the case of normal connection of the motor, and in the case of reverse rotation of the motor, the output of the reverse rotation inversion circuit that reverses is observed. A method for determining the reverse rotation connection of the motor. 2. When power is turned on, data of one or more rotations is detected from an A-phase pulse output from an absolute value encoder, and then less than one rotation is detected by an A-phase pulse and a B-phase pulse. Thereafter, the absolute value encoder is a motor position detecting device in a servo control device acting as an incremental encoder, and receives the B-phase pulse of the absolute value encoder, and outputs the B-phase pulse as it is in the case of a normal rotation connection of the motor. ,
In the case of reverse rotation connection of the motor, a reverse rotation inversion circuit that inverts and outputs a B-phase pulse, an A-phase pulse of the absolute value encoder, and an output pulse of the reverse rotation inversion circuit,
A code discriminating / counter circuit for discriminating and counting the sign to determine a position, and when power is turned on, detecting rotation speed data of one or more rotations from the A-phase pulse, and then detecting 1 count from the count value of the sign discriminating / counter circuit. A CPU for detecting a rotational speed less than one rotation, observing a B-phase pulse while detecting data for one or more rotations, and inverting the sign of one or more rotational speed data if the B-phase pulse is at a low level; A motor position detecting device having: 3. The motor position detecting device according to claim 2, wherein a line driver and a line receiver are connected between said reverse rotation inverting circuit and said code discriminating circuit.