JP3594203B2 - Motor control device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a motor control device that satisfactorily controls the position of a position controllable motor such as a servomotor.
[0002]
[Prior art]
For example, an XY table used in a semiconductor manufacturing apparatus (a pellet bonding apparatus or a wire bonding apparatus) can use a servomotor as a drive source and can control the position to a predetermined position.
[0003]
As shown in FIG. 3, in the servo motor control device for controlling the servo motor, the control device 1 outputs a rotation speed command signal h for rotating the servo motor 2 at a predetermined rotation speed, and the servo driver 3 The servo motor 2 is rotated at a speed proportional to the rotation speed command signal h. The tacho-generate encoder 4 detects the rotation speed and the position of the servo motor 2, outputs a rotation speed detection signal j to the servo driver 3, and outputs a position detection signal m to the control device 1, Then, it outputs the position detection signal k to the analog lock circuit 6 as a position correcting means. The servo driver 3 feedback-controls the rotation speed of the servo motor 2 based on the rotation speed detection signal j, and the control device 1 recognizes the position deviation of the servo motor 2 by a calculator (not shown) based on the position detection signal m. Then, a position correction signal n is output based on the position shift, and the position of the servo motor 2 is feedback-controlled. Then, the analog lock circuit 6 recognizes the stop position when the servomotor 2 is in the stop state based on the position detection signal k, and the stop position of the servomotor 2 is shifted from the predetermined stop position. At this time, in order to correct this deviation, a position correction signal 1 is output to the servo driver 3, and the stop position of the servo motor 2 is feedback-controlled.
[0004]
The analog lock circuit 6 corrects the shift of the stop position in a range that cannot be recognized by the arithmetic unit of the control device 1. That is, since the arithmetic unit of the control device 1 processes the position detection signal m which is a pulse signal, it is impossible to recognize even if a position shift of less than one pulse occurs in the servomotor 2. . On the other hand, the analog lock circuit 6 processes the position detection signal k, which is an analog signal composed of an Asin wave and a Bsin wave having phases different from each other by 90 °, so that the arithmetic unit of the control device 1 cannot recognize 1 It is possible to correct a stop position deviation less than a pulse.
[0005]
[Problems to be solved by the invention]
However, in the tacho-generate encoder 4 used in the above-described conventional servomotor control device, the Asin wave or Bsin wave is shifted (offset) in the displacement axis direction with respect to the origin due to a manufacturing error. The phase of the wave and the Bsin wave may be shifted. Therefore, in this case, the correction of the shift of the stop position with respect to the servomotor 2 performed by the analog lock circuit 6 may not be strictly performed.
[0006]
The present invention has been made in view of the above circumstances, and has as its object to provide a motor control system that can control the position of a motor strictly and with high resolution.
[0007]
[Means for Solving the Problems]
The present invention provides a motor, a driver for driving the motor, a control device for outputting a drive command to the motor via the driver, a detector connected to the motor for detecting a position of the motor, The position detection signal of the motor output from the device is taken in as an analog signal, the position of the motor is recognized based on the analog signal, and when the position is deviated from a predetermined position, the deviation is corrected. And a position correcting means for outputting a position correction signal for correcting the position of the motor to the driver to correct the position of the motor, wherein the detector comprises an Asin wave and a Bsin wave. An analog signal is output, and a waveform shaping means for correcting the displacement in the displacement direction of the Asin wave and the Bsin wave with respect to the origin and the phase shift of both waves is provided. Only, the position correcting means, on the basis of the waveform-shaped signal by the waveform shaping means, when deviated to a predetermined position where the position of the motor is commanded by the control unit, this deviation A position correction signal to be corrected is output to a driver .
[0009]
According to the present invention, the waveform shaping means is provided, and the waveform shaping means shapes the waveform of the analog signal output from the detector and taken into the position correcting means. Since the analog signal thus processed can be processed, the position of the motor can be strictly controlled with high resolution.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a servo motor control device to which one embodiment of a motor control device according to the present invention is applied. FIG. 2 is a graph showing waveforms of the detection signals (Asin wave and Bsin wave) output from the tacho-generate encoder of FIG.
[0011]
As shown in FIG. 1, a servo motor control device 10 for controlling the rotation speed and position of a servo motor 11 includes a control device 12, a servo driver 13, a tacho-generating encoder 14 as a detector, and an analog lock as a position correcting means. It comprises a circuit 15, a waveform shaping circuit 16, an A / D converter 17, and a D / A converter 18. An A / D converter 17, a waveform shaping circuit 16, and a D / A converter 18 are sequentially arranged between the tacho-generate encoder 14 and the analog lock circuit 15 from the tacho-generate encoder 14 side.
[0012]
The control device 12 outputs a rotation speed command signal a for rotating the servo motor 11 at a predetermined rotation speed to the servo driver 13. The servo driver 13 rotates the servomotor 11 at a speed proportional to the rotation speed command signal a.
[0013]
The tacho-generate encoder 14 detects the rotation speed and the position of the servo motor 11 and outputs a detection signal relating to the rotation speed to the servo driver 13 as a rotation speed detection signal c. The servo driver 13 performs feedback control of the rotation speed of the servo motor 11.
[0014]
Further, the tacho-generate encoder 14 outputs a detection signal relating to the position among the detection signals to the analog lock circuit 15 as a position detection signal d. The position detection signal d is an analog signal composed of the Asin wave 19A and the Bsin wave 19B shown in FIG. 2, and the Asin wave 19A and the Bsin wave 19B have the same period, the same amplitude, and a phase difference of 90 °. It is a sine curve.
[0015]
The Asin wave 19A and the Bsin wave 19B as the position detection signal d are not directly taken into the analog lock circuit 15, but are taken into the A / D converter 17 first and are converted from analog signals into digital signals.
[0016]
The waveform shaping circuit 16 includes an arithmetic unit (not shown), and the arithmetic unit shapes the waveforms of the Asin wave 19A and the Bsin wave 19B that have been converted into digital signals by the A / D converter 17. That is, based on the maximum value α and the minimum value β of the displacement in the Asin wave 19A or Bsin wave 19B, the offset amount of the Asin wave 19A or Bsin wave 19B in the displacement axis direction with respect to the origin 0 is detected. The arithmetic unit of the waveform shaping circuit 16 detects a phase shift between the Asin wave 19A and the Bsin wave 19B, for example, from the position of the time axis intersection of the Asin wave 19A and the Bsin wave 19B. The arithmetic unit of the waveform shaping circuit 16 further moves the Asin wave 19A or the Bsin wave 19B in the displacement axis direction and the time axis direction in FIG. 2 until both the offset and the phase shift become 0 (zero). Is corrected and the waveform is shaped.
[0017]
The waveform of the Asin wave 19A and the Bsin wave 19B digitized by the A / D converter 17 is shaped by the arithmetic unit of the waveform shaping circuit 16 as described above, and the analog signal is converted by the D / A converter 18 And output to the analog lock circuit 15.
[0018]
The analog lock circuit 15 determines the stop position when the servomotor 11 is in the stop state based on the position detection signal d that has been waveform-shaped by the waveform shaping circuit 16 and returned to the analog signal by the D / A converter 18. When the stop position is deviated from a predetermined stop position instructed by the control device 12, a position correction signal e for correcting the deviation is output to the servo driver 13, and The motor 11 is feedback-controlled.
[0019]
The position deviation in the range recognizable by the arithmetic unit of the control device 12 is recognized by the control device 12 based on the position detection signal f, and the position correction signal g from the control device 12 is output to the servo driver 13. Will be corrected.
[0020]
According to the above-described embodiment, the position detection signal d (Asin wave 19A, Bsin wave 19B) detected from the tacho-generate encoder 14 is converted into a digital signal by the A / D converter 17, and the waveform is formed by the waveform shaping circuit 16. Since the offset amount and the position shift amount are corrected and the waveform is shaped, the analog lock circuit 15 uses the waveform-shaped position detection signal d (Asin wave 19A, Bsin wave 19B) to detect the position shift of the servo motor 11. An accurate position correction signal e for correction can be output. As described above, since the position detection signal d input to the analog lock circuit 15 is subjected to the waveform shaping process by the waveform shaping circuit 16, the stop position when the servo motor 11 is stopped by the analog lock circuit 15 is corrected. Can be performed strictly and with high resolution.
[0021]
In the above embodiment, the example in which the waveform shaping circuit 16 is provided between the tachogenerator encoder 14 and the analog lock circuit 15 has been described, but the waveform shaping process is performed using the arithmetic unit of the control device 12. You may make it. That is, the position detection signal d output from the tacho-generate encoder 14 is converted into a digital signal by the A / D converter 17, and the digitized position detection signal d is subjected to waveform shaping using the arithmetic unit of the control device 12. After the processing and the waveform detection processing, the position detection signal d is converted into an analog signal by the D / A converter 18, the signal may be input to the analog lock circuit 15.
[0022]
Further, the analog lock circuit 15, the waveform shaping circuit 16, the A / D converter 17, and the D / A converter 18 are all taken into the control device 12, and the waveform shaping process and the analog lock process are performed in the control device 12. You may do it.
[0023]
Further, in the above embodiment, the analog lock circuit 15 recognizes the stop position when the servo motor 11 is in the stop state, and shifts the stop position from a predetermined stop position commanded by the control device 12. In the example described above, the position correction signal e for correcting the displacement is output when the position is generated. However, the position in the time series when the servo motor 11 is in the rotating state is recognized, and this position is When a shift has occurred with respect to the base position, a correction signal for correcting the shift may be output. In this case, the servo motor 11 can accurately follow the drive command of the control device 12.
[0024]
【The invention's effect】
As described above, according to the motor control device of the present invention, the position of the motor can be strictly controlled with high resolution.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a servo motor control device to which one embodiment of a motor control device according to the present invention is applied.
FIG. 2 is a graph showing waveforms of analog signals (Asin wave and Bsin wave) output from the tacho-generate encoder of FIG. 1;
FIG. 3 is a block diagram showing a conventional servo motor control device.
[Explanation of symbols]
Reference Signs List 10 servo motor control device 11 servo motor 12 control device 13 servo driver 14 tacho generate encoder 15 analog lock circuit (position correction means)
16 Waveform shaping circuit 17 A / D converter 18 D / A converter 19A Asin wave 19B Bsin wave d Position detection signal e Position correction signal

Claims (1)

Motor and
A driver for driving the motor,
A control device that outputs a drive command to the motor via the driver,
A detector connected to the motor and detecting a position of the motor;
The position detection signal of the motor output from the detector is captured as an analog signal, and the position of the motor is recognized based on the analog signal. When the position is shifted from a predetermined position, the shift is determined. Position correction means for outputting a position correction signal to correct the position of the motor to correct the position of the motor to correct the position of the motor,
In the motor control device having
The detector outputs an analog signal composed of an Asin wave and a Bsin wave,
Waveform shaping means for correcting the displacement of the Asin wave and the Bsin wave in the displacement direction with respect to the origin and the phase shift of both waves are provided.
Said position correcting means, on the basis of the waveform-shaped signal by the waveform shaping means, when deviated to a predetermined position where the position of the motor is commanded by the control unit, to correct this deviation A motor control device for outputting a position correction signal to a driver .

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