JPH0916262A - Motor controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control the position of a motor severely with high resolution. SOLUTION: The servomotor controller 10, having a servomotor 11, a servodriver 13 which drives the servomotor 11, a controller 12 which outputs a driving command to the servomotor 11 through the servodriver 13, a tachometer generating encoder 14 which is connected to the servomotor 11 and detects the position of the servomotor 11, and an analog lock circuit 15 which inputs the position detection signal of the servomotor 11 outputted by the tachometer generating encoder 14 as an analog signal, recognizes the position of the servomotor 11 on the basis of the analog signal, and outputs a correction signal for correcting the position of the servomotor 11 to the servodriver 13 if the recognized position shifts from a specific position to correct the position of the servomotor 11, is provided with a waveform shaping circuit 16 which shapes the waveform of the analog signal inputted to the analog lock circuit 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor control device for satisfactorily controlling the position of a position controllable motor such as a servo motor.

[0002]

2. Description of the Related Art For example, an XY table used in a semiconductor manufacturing apparatus (pellet bonding apparatus or wire bonding apparatus) has a servo motor as a drive source and can be positionally controlled at a predetermined position.

In the servo motor control device for controlling this servo motor, as shown in FIG. 3, 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 However, the servomotor 2 is rotated at a speed proportional to the rotation speed command signal h.
The tachogenerator encoder 4 detects the rotation speed and the position of the servomotor 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 among the detection signals. Then, the position detection signal k is output to the analog lock circuit 6 as the 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,
The control device 1 recognizes the positional deviation of the servo motor 2 by a calculator (not shown) based on the position detection signal m, outputs a position correction signal n based on the positional deviation, and feedback-controls the position of the servo motor 2. To do. Then, the analog lock circuit 6 recognizes the stop position when the servo motor 2 is in the stopped state based on the position detection signal k, and the stop position of the servo motor 2 deviates from the predetermined stop position. At this time, in order to correct this deviation, the position correction signal 1 is output to the servo driver 3 and the stop position of the servo motor 2 is feedback-controlled.

The analog lock circuit 6 is provided in the control device 1
This is to correct the deviation of the stop position in a range that cannot be recognized by the arithmetic unit of. That is, since the arithmetic unit of the control device 1 processes the position detection signal m which is a pulse signal, even if the servo motor 2 has a positional deviation of less than one pulse, it cannot be recognized. . On the other hand, the analog lock circuit 6 has a phase difference of 90 ° between Asin wave and Bsi wave.
By processing the position detection signal k, which is an analog signal composed of n waves, it is possible to correct the stop position deviation of less than one pulse that cannot be recognized by the arithmetic unit of the control device 1.

[0005]

However, the tacho-generator encoder 4 used in the above-mentioned conventional servo motor control device has a problem that the Asin
Wave or Bsin wave may be displaced (offset) in the displacement axis direction with respect to the origin, or the phases of the Asin wave and Bsin wave may be misaligned. Therefore, in this case, the correction of the shift of the stop position with respect to the servo motor 2 performed by the analog lock circuit 6 may not be strictly performed.

The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a motor control system capable of strictly controlling the position of a motor with high resolution.

[0007]

According to a first aspect of the present invention, a motor, a driver for driving the motor, a control device for outputting a drive command to the motor via the driver, and a motor are connected to the motor. The detector for detecting the position of the motor and the position detection signal of the motor output from the detector are taken in as an analog signal, and the position of the motor is recognized based on the analog signal, and this position is set to a predetermined value. A motor control device having position correction means for correcting the position of the motor by correcting the position of the motor to correct the position of the motor when the position is displaced. Waveform shaping means for shaping the waveform of the analog signal taken in by the position correction means is provided.

According to a second aspect of the invention, in the first aspect of the invention, the analog signal output from the detector is composed of an Asin wave and a Bsin wave, and the waveform shaping means is
The deviation of the Asin wave and the Bsin wave in the displacement direction with respect to the origin and the phase deviation of both waves are corrected.

According to the present invention, since the waveform shaping means is provided and the waveform of the analog signal output from the detector and taken into the position correcting means is shaped by the waveform shaping means, the position correcting means is provided. Since the analog signal whose waveform is shaped can be processed, the position of the motor can be controlled precisely and with high resolution.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a servo motor control device to which an embodiment of a motor control device according to the present invention is applied. FIG. 2 is a graph showing the waveforms of the detection signals (A sin wave and B sin wave) output from the tachogenerator encoder of FIG.

As shown in FIG. 1, a servo motor control device 10 for controlling the rotation speed and position of the servo motor 11 is shown.
Is a controller 12, a servo driver 13, a tachogenerator encoder 14 as a detector, an analog lock circuit 15 as a position correcting means, and a waveform shaping circuit 1.
6, an A / D converter 17 and a D / A converter 18 are provided. An A / D converter 17, a waveform shaping circuit 16, and a D / A converter 18 are sequentially arranged between the tachogenerator encoder 14 and the analog lock circuit 15 from the tachogenerator encoder 14 side.

The controller 12 outputs to the servo driver 13 a rotation speed command signal a for rotating the servo motor 11 at a predetermined rotation speed. The servo driver 13 rotates the servo motor 11 at a speed proportional to the rotation speed command signal a.

The tacho-generator encoder 14 detects the rotation speed and 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 feedback-controls the rotation speed of the servo motor 11.

Further, the tachogenerator encoder 14
Outputs a position-related detection signal among the above detection signals to the analog lock circuit 15 as a position detection signal d.
This position detection signal d is the Asin wave 19A and B shown in FIG.
It is an analog signal composed of a sin wave 19B, and these Asin wave 19A and Bsin wave 19B are sine curves having the same period and the same amplitude and a phase difference of 90 °.

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 first taken into the A / D converter 17 and converted from an analog signal to a digital signal. To be done.

The waveform shaping circuit 16 includes an arithmetic unit (not shown), and this arithmetic unit shapes the waveforms of the Asin wave 19A and Bsin wave 19B 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 the Bsin wave 19B, this A
The offset amount of the sin wave 19A or B sin wave 19B with respect to the origin 0 in the displacement axis direction is detected. The arithmetic unit of the waveform shaping circuit 16 is, for example, an Asin wave 19A and a Bsi wave.
From the position of the time axis intersection with the n wave 19B, the Asin wave 19A
And the phase shift between the Bsin wave 19B is detected. The arithmetic unit of the analog lock circuit 16 further moves the Asin wave 19A or the Bsin wave 19B in the displacement axis direction and the time axis direction of FIG. Correct the deviation of the waveform and shape the waveform.

The Asin wave 19A and the Bsin wave 19B converted into digital signals by the A / D converter 17 have their waveforms shaped by the arithmetic unit of the waveform shaping circuit 16 as described above, and D / A
It is converted into an analog signal by the converter 18 and output to the analog lock circuit 15.

In the analog lock circuit 15, when the servo motor 11 is in a stopped state, the waveform is shaped by the waveform shaping circuit 16 and the position detection signal d is returned to the analog signal by the D / A converter 18 based on the position detection signal d. The stop position is recognized, and when the stop position deviates from a predetermined stop position instructed by the controller 12, a position correction signal e for correcting the deviation is output to the servo driver 13. Then, the servo motor 11 is feedback-controlled.

The positional deviation within 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 this control device 12 is output to the servo driver 13. Will be corrected.

According to the above embodiment, the position detection signal d (Asi detected by the tachogenerator encoder 14 is detected.
The n-wave 19A and the Bsin wave 19B) are converted into digital signals by the A / D converter 17, and the waveform shaping circuit 16 corrects the offset amount and the positional deviation amount to perform waveform shaping. By using the waveform-shaped position detection signal d (Asin wave 19A, Bsin wave 19B), an accurate position correction signal e for correcting the position shift of the servomotor 11 can be output. As described above, since the position detection signal d input to the analog lock circuit 15 is waveform-shaped by the waveform shaping circuit 16, the stop position is corrected by the analog lock circuit 15 when the servo motor 11 is in the stopped state. Can be performed strictly and with high resolution.

In the above embodiment, the example in which the waveform shaping circuit 16 is provided between the tacho-generator encoder 14 and the analog lock circuit 15 has been described, but an arithmetic unit having a waveform shaping process in the control device 12 is described. You may make it perform using. That is, the position detection signal d output from the tachogenerator encoder 14 is converted into the A / D converter 17
And digitizes the digitalized position detection signal d by using the arithmetic unit of the control device 12, and the waveform-shaped position detection signal d is D /
The analog signal may be converted into an analog signal by the A converter 18 and then input to the analog lock circuit 15.

Further, the analog lock circuit 15, the waveform shaping circuit 16, the A / D converter 17, and the D / A converter 18 are all incorporated in the control device 12, and the waveform shaping process and the analog lock process are performed in the control device 12. May be performed.

Further, in the above embodiment, the analog lock circuit 15 recognizes the stop position when the servomotor 11 is in the stopped state, and this stop position is compared with the predetermined stop position instructed by the controller 12. Although an example of outputting the position correction signal e that corrects the deviation when the deviation occurs, the time-series position when the servo motor 11 is in the rotating state is recognized, and this position is recognized by the controller 12. When there is a deviation with respect to the position based on the command, the correction signal for correcting the deviation may be output. In this case, the servo motor 11 can accurately follow the drive command of the control device 12.

[0024]

As described above, according to the motor control device of the present invention, the position of the motor can be controlled precisely and with high resolution.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a servo motor control device to which an embodiment of a motor control device according to the present invention is applied.

FIG. 2 is a graph showing waveforms of analog signals (A sin wave and B sin wave) output from the tachogenerator encoder of FIG. 1.

FIG. 3 is a block diagram showing a conventional servo motor control device.

[Explanation of symbols]

 10 Servo Motor Control Device 11 Servo Motor 12 Control Device 13 Servo Driver 14 Tacho-Generate Encoder 15 Analog Lock Circuit (Position Correcting 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 (2)

[Claims] 1. A motor, a driver for driving the motor, a control device for outputting a drive command to the motor via the driver, and a detector connected to the motor for detecting the position of the motor. The position detection signal of the motor output from the detector is taken in as an analog signal, the position of the motor is recognized based on this analog signal, and when this position deviates from a predetermined position, this deviation is detected. A motor controller having a position correcting means for correcting the position of the motor by outputting a correction signal for correcting the position of the motor to the driver so as to correct the waveform of the analog signal taken in by the position correcting means. A motor control device comprising: 2. The analog signal output from the detector is
The motor according to claim 1, wherein the motor includes an Asin wave and a Bsin wave, and the waveform shaping unit corrects a deviation in a displacement direction of the Asin wave and the Bsin wave with respect to an origin and a phase deviation between both waves. Control device