KR970002733B1 - Transmission system for encoder output - Google Patents

Abstract

There is provided an encoder output transmission system to which an optical fiber is applied. The transmission system includes: plural wave shaping parts(32, 42) which respectively amplifies waves passing through six channels detected through a velocity detection part(31) and a position signal detection part(41); a transmission signal generating part(30) which comprises plural frequency modulating parts(33, 43), the modulating parts(33, 43) modulating the amplified and shaped six channels signals according to transmission frequency signals(f1-f6) input from a carrier frequency generating part(34) outputting frequency signals modulated according to a transmission frequency signal of a predetermined level; and a signal converting and transmitting part(35) for encoding the modulated frequency signals(A*, B*, Z*, U*, V*, W*) to be adaptive for a local area optical telecommunication.

Description

Encoder output transmission system

1 is a block diagram showing an embodiment of an encoder output transmission system according to the prior art,

2 is a block diagram showing an embodiment of an encoder output transmission system according to the present invention.

* Explanation of symbols for main parts of the drawings

10: encoder output transmission system 11,31: speed detector

12: channel amplifier circuit section 13,23: waveform shaping circuit section

14,24: output drive circuit 21,41: position signal detection

22: position signal amplifier circuit portion 30: transmission signal generator

32, 42: amplification and waveform shaping part 33: frequency modulating part

34: carrier frequency generator 35: signal conversion and transmission unit

36: demodulation unit

The present invention relates to an encoder output transmission system for an AC servo motor, and more particularly, to an encoder output transmission system using an optical fiber transmission cable to downsize the output transmission line of the encoder.

In general, a motor rotating only by connecting to a power source includes an AC motor and a DC motor. The AC motor has been widely used for simple FA applications, and the DC motor has been used for servos. Such AC motors need to be controlled by remote control because they operate in conjunction with peripheral devices in more complex FA applications.

1 is a block diagram showing an embodiment of an encoder output transmission system according to the prior art.

Referring to FIG. 1, the encoder output transmission system 10 detects a stimulus and a magnetic flux from an AC motor and controls the operation of the motor. First, a speed detector including an optical sensor (not shown) ( 11) the magnetic flux according to the A, B, Z channel is detected, the magnetic flux according to the A, B, Z channel is detected, the A, B, Z channel signal is a predetermined level by the channel amplifier circuit 12 After amplified to, it is applied to the waveform shaping circuit unit 13. Subsequently, the A, B, and Z channel signals applied to the waveform shaping circuit unit 13 are waveform shaped into signals according to the assigned channels, and then six channels A, B, ..., through the output drive circuit unit 14. Z,)

Similarly, magnetic poles corresponding to U, V, and W channels are detected through the position signal detection unit 21 including an optical sensor (not shown), and the U, V, and W channel signals are transmitted to the position signal amplification circuit unit 22. After being amplified to a predetermined level, it is applied to the waveform shaping circuit section 23. Subsequently, the U, V, and W channel signals applied to the waveform shaping circuit section 23 are waveform shaped into signals according to the assigned channels, and then six channels U, V, ..., through the output drive circuit section 24. Is output as W,).

As a result, the output drive circuits 14 and 24 transmit signals A, B, Z, U, V, W, read from the optical sensor of the AC motor to 12 channels. As the signal is transmitted, the signal line is excessive when the signal is transmitted, the noise by the external factor is exposed, and when the long distance transmission is made, it is impossible to receive the signal at the final reception stage.

Therefore, the present invention is to solve the above problems of the prior art, an object of the present invention is to configure the system by transmitting a signal to be transmitted to each frequency channel of the encoder method using a frequency modulation method, and then transmitted through the optical fiber cable It is possible to simplify and to provide an encoder output transmission system that is easy for short-range and long-distance communication.

Another object of the present invention is to frequency-modulate various three-phase speed detection signals and position detection signals detected by an AC servo motor to a carrier frequency, and then transfer the signals to an optical fiber cable through signal conversion to maximize the transmission efficiency and simplify the system. An encoder output transmission system can be provided.

Features of the encoder output transmission system according to the present invention for achieving the above object is a plurality of amplification and waveform shaping section for amplifying the waveform after amplifying each of the six channels detected through the speed detector and the position signal detector, A transmission signal generator comprising a plurality of frequency modulators for outputting the six waveforms of the waveform-shaped channel signals modulated according to transmission frequency signals of a predetermined level supplied from a carrier frequency generator; A signal conversion and transmission unit for encoding the modulated frequency signal from the transmission signal generator so as to be suitable for optical local area communication; An optical fiber cable is transmitted to a demodulator for demodulating the encoded signal into an original signal.

Hereinafter, a preferred embodiment of the encoder output transmission system according to the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram showing an embodiment of an encoder output transmission system according to the present invention.

Referring to FIG. 2, an encoder output transmission system according to the present invention is mounted on a printed circuit board (not shown) of an AC motor, and includes an optical sensing sensor (not shown) for detecting magnetic flux and magnetic pole of the motor, respectively. A plurality of amplification and waveform shaping units 32 and 42 for amplifying and then waveform shaping the six channels detected by the speed detecting unit 31 and the position signal detecting unit 41, respectively; A plurality of frequency modulators for outputting the signal A, B, Z, U, V, W modulated in accordance with a predetermined level of the transmission frequency signals f1 to f6 supplied from the carrier frequency generator 34 A transmission signal generator 30 composed of 33 and 43; A signal conversion and transmission unit 35 for encoding the modulated frequency signals A *, B *, Z *, U *, V *, W * from the transmission signal generator 30 so as to be suitable for optical local area communication. )Wow ; An optical fiber cable (OFC) for transmission is provided to a demodulation section 36 for demodulating the encoded signal into an original signal.

Since it is comprised in this way, first, the speed detection part 31 detects and detects the speed of an AC motor by three-phase channels A, B, and Z, and at the same time, the position signal detection part 41 carries out three-phase for driving a motor. Stimulation of the coil is also detected by detecting the three-phase channel (U, V, W).

The signals detected through the speed detector 31 and the position signal detector 41 are applied to the amplification and waveform shaping units 32 and 42, respectively, amplified to a predetermined level, and then waveform-shaped into signals suitable for frequency modulation. do. In addition, the waveform-formed six channel signals A, B, Z, U, V, and W are frequency modulated to transmit in a short channel. In this case, a predetermined level of transmission frequency supplied from the carrier frequency generator 34 is provided. According to the signals f1, f2, f3, f4, f5, and f6, three channels are carried in one frequency transmission signal, and the modulated frequency signals A *, B ＊, Z ＊, U ＊, V ＊, W *) is output through two lines.

The frequency signals A *, B *, Z *, U *, V *, W * of each channel are encoded to be suitable for optical local area communication, which is performed by the signal conversion and transmission unit 35. It is made by an optical attenuator and an optical modulator. In addition, the coded signal is short-range or long-distance communication by the optical fiber cable (OFC), the coded signal is reproduced as a raw signal by a complex.

In the encoder transmission system according to the present invention configured and operated as described above, the six channels detected through the speed detector and the position signal detector are amplified by a plurality of amplification and waveform shaping sections, respectively, and then the waveform shaping is performed. Modulating and outputting the frequency signals through a plurality of frequency modulators according to a predetermined level of transmission frequency signals supplied from a carrier frequency generator, and then converting the modulated frequency signals to be suitable for optical local area communication. By implementing the method of encoding by the transmission unit and transmitting to the demodulator by the optical fiber cable, there is an advantage that ultra-precision control is possible by reducing noise caused by the environmental elements and zeroing the signal transmission error rate.

In addition, the encoder output transmission system according to the present invention can transmit 12 encoder signals with a minimum transmission cable, there is an advantage that can be short-range and long-distance transmission.

Claims (1)

A plurality of amplification and waveform shaping parts for amplifying and then waveform shaping each of the six channels detected by the speed detector and the position signal detector, and transmission of a predetermined level supplied from the carrier frequency generator for the waveform shaped six channel signals. A transmission signal generator comprising a plurality of frequency modulators for outputting a frequency signal modulated according to the frequency signal; A signal conversion and transmission unit for encoding the modulated frequency signal from the transmission signal generator so as to be suitable for optical local area communication; And an optical fiber cable for transmitting the coded signal to a demodulator for demodulating the original signal into an original signal.