JPH05336793A - Controlling equipment of servomotor - Google Patents

Abstract

PURPOSE:To suppress fluctuation of an output torque both for a motor for which a U-phase interphase voltage is synchronized with a U-phase CS signal and for a motor for which a U-phase line voltage is synchronized with the U-phase CS signal. CONSTITUTION:An electrical angle corresponding to a commutation signal (d) is obtained by an electrical angle determining part 11, while a U-phase edge of the signal (d) is detected by an edge detecting part 12 and an electrical angle corresponding thereto is abtained. Moreover, an electrical angle offset corresponding to a phase difference between a U-phase interphase induced voltage and the phase U of the signal (d) is outputted by an electrical angle offset output part 13. An electrical angle initial setting part 14 sets in a counter 3 an addition value of the electrical angle of the electrical angle determining part 11 and the electrical angle offset when a power source is made, and moreover, an electrical angle resetting part 15 resets in the counter 3 an addition value of the electrical angle of the edge detecting part 12 and the electrical angle offset when the U-phase edge of the signal (d) is detected. A servomotor 1 is subjected to a drive control by a sine wave output from a sine wave output part 4 which is computed by using set values obtained in the above.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a servo motor controller such as a digital servo controller.

[0002]

2. Description of the Related Art FIG. 4 is a block diagram showing the configuration of a conventional servomotor control device having an incremental encoder. In FIG. 4, an incremental encoder (hereinafter referred to as an encoder) connected to the servo motor 1
Reference numeral 2 is connected to the counter 3, and the counter 3 counts the A-phase and B-phase signals a from the encoder 2 and outputs the count value as the electrical angle value b of the alternating current flowing through the servomotor 1. Sine wave output unit 4 connected to this counter 3
Receives the electrical angle value b from the counter 3, forms a sine wave output c from the electrical angle value b, and outputs it.

The rectangular wave output section 5 to which the encoder 2 is connected has a three-phase (U, V, W) CS from the encoder 2.
The combination of the signals (three-phase commutation signals) d is determined, and a rectangular wave e is formed and output from the values corresponding to the combination. The switching unit 6 receives the rectangular wave e from the rectangular wave output unit 5 and the sine wave output c from the sine wave output unit 4, and selects and outputs one of them. The rectangular wave e is set to be output immediately after the power is turned on. Further, the CS signal processing unit 7 to which the encoder 2 is connected is connected to the switching unit 6, detects the edge of the U-phase CS signal (U-phase commutation signal) from the encoder 2, and detects the first edge after the power is turned on. At this time, the electrical angle value corresponding to the edge is set in the counter 3, and the switching unit 6 is controlled to switch to the sine wave output unit 4 side.

Further, each phase current command computing unit 8 to which the output end of the switching unit 6 is connected has a rectangular wave e from the rectangular wave output unit 5 or a sine wave output unit 4 input from the switching unit 6. A sine wave output c and a torque command f are used to calculate and output a current command g for each phase (U, V, W). The current control unit 9 to which the current command calculation unit 8 is connected receives the phase current commands g from the phase current command calculation units 8 and the current feedback value h as inputs, and outputs the PWM command i. The PWM inverter unit 10 to which the current control unit 9 is connected is connected to the servo motor 1 and receives the PWM command i as an input and outputs the drive current j of the servo motor 1.

The operation of the servo motor control device constructed as described above will be described below. FIG. 5 shows the U-phase interphase voltage and the U-phase C in the servo motor control device of FIG.
CW the motor 1a synchronized with the S signal with the torque in the CW direction.
FIG. 3 is a waveform diagram of each main part when rotated in a direction, where A is a motor output torque waveform, B is a counter value (electrical angle value) waveform, C is a phase current waveform, and D is a phase CS signal waveform. Shows. The time point m and the time point n in FIG.
At the time when the S signal d changes, time k is the time when the power is turned on.
Further, only the rising edge is detected for the edge detection of the U-phase CS signal, and the first rising edge after the power is turned on is the time point p. In addition, the first U after turning on the power
Until the rising edge of the phase CS signal is detected (section kp), the exact electrical angle position is not known. Therefore, the rough electrical angle position is determined by the combination of the phase CS signals d, and the approximate waveform (rectangular wave) is calculated.・ Slanted areas Q ₁ , Q ₂ , Q
₃ ) is formed to drive the motor 1a. Further, after detecting the rising edge of the U-phase CS signal, the accurate electrical angle value b is known, and the sine wave output c having a phase corresponding to the electrical angle value b is formed to drive and control the motor 1a. ing.

FIG. 6 shows a motor 1b in which the U-phase line voltage and the U-phase CS signal are synchronized in the servo motor control device of FIG.
Is a waveform diagram of each main part when C is rotated in the CW direction with torque in the CW direction. A is a motor output torque waveform, B is a counter value (electrical angle value) waveform, C is a phase current waveform, and further D is a waveform. Shows the CS signal waveform of each phase. M, n, in FIG.
The time points k and p are the same as the time points described in FIG.
Also, the method of driving the motor 1b after the power is turned on until the first rising edge of the U-phase CS signal is detected or after the rising edge of the U-phase CS signal is detected has been described with reference to FIG. It is the same as the one. The difference is that, for the motor 1b in which the U-phase line voltage and the U-phase CS signal are synchronized, there is a difference of 30 ° in electrical angle between the electrical angle 0 (zero) point and the rising point of the U-phase CS signal. It is to be. In this case, in the section kp, the phase of the drive current is deviated by a maximum of 60 ° with respect to the phase (dotted line portion in C of FIG. 6) which should be originally (immediately before each change point of the CS signal), and the motor 1b The output torque of 1 has a large fluctuation as shown in FIG.

[0007]

In the above-mentioned conventional servo motor control device, when it is attempted to drive the motor 1b in which the U-phase line voltage and the U-phase CS signal are synchronized, the first U-phase CS after the power is turned on. Until the edge of the signal is detected, the output torque fluctuation of the motor 1b becomes large, and when the power is turned on for the first time, the motor 1b depends on its electrical angle position.
Since the output torque of b is insufficient, or such a torque fluctuation causes oscillation, there arises a problem that the servo gain cannot be increased, which is difficult to cope with.

The present invention is intended to solve the above-mentioned conventional problems, and includes a motor in which the U-phase interphase voltage and the U-phase CS signal are synchronized,
It is an object of the present invention to provide a servo motor control device that can suppress fluctuations in motor output voltage for both motors in which the U-phase line voltage and the U-phase CS signal are synchronized.

[0009]

In order to solve the above-mentioned problems, a servo motor control device of the present invention is a servo drive control for a servo motor provided with an incremental encoder according to a current command calculated by a sine wave output and a torque command. A motor control device, wherein a counter for inputting and counting the A-phase and B-phase signals from the incremental encoder and outputting an electrical angle value of an alternating current flowing to the servo motor, and an electrical angle value of the counter output as inputs A sine wave output section that outputs the sine wave output, an input of the commutation signal output by the incremental encoder, an electrical angle determination section that outputs an electrical angle value corresponding to the commutation signal, and the commutation signal Detect the U-phase edge and output the electrical angle value corresponding to the U-phase edge. An edge detection unit, an electrical angle offset output unit that outputs an electrical angle offset corresponding to the phase difference between the U-phase interphase induced voltage and the U-phase commutation signal from the incremental encoder, and the electrical angle determination unit when the power is turned on. An electrical angle initial setting unit for setting the added value of the electrical angle value of the output and the electrical angle offset in the counter; and an electrical angle value of the edge detection unit output when a U-phase edge of the commutation signal is detected. An electrical angle resetting unit that resets the added value with the electrical angle offset in the counter is provided.

[0010]

With the above structure, the electrical angle determination unit outputs the electrical angle corresponding to the commutation signal, the edge detection unit detects the U-phase edge of the commutation signal, and outputs the corresponding electrical angle. , The electrical angle offset output unit outputs an electrical angle offset corresponding to the phase difference between the U-phase inter-phase induced voltage and the U phase of the commutation signal, and the electrical angle initial setting unit outputs the electrical angle determination unit output when the power is turned on. The added value of the electrical angle and the electrical angle offset is set in the counter, and the electrical angle resetting unit detects the U-phase edge of the commutation signal and detects the electrical angle and the electrical angle offset of the output of the edge detection unit. Since the added value is reset in the counter and the sine wave output from the sine wave output unit that is calculated and output using these counter values drives and controls the servo motor,
The motor output torque remains constant during the control based on the counter setting value set by the electrical angle initial setting unit, which occurs when a motor in which the U-phase line voltage and the U-phase CS signal are synchronized is used as in the conventional case. , The problem that the servo gain cannot be increased due to resonance due to the output torque fluctuation of the motor is solved, and the motor in which the U phase phase voltage and the U phase CS signal are synchronized, and the U phase line voltage and the U phase CS signal Can be used for any of the motors that are synchronized with each other.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. It should be noted that the same effects as those of the conventional example are given the same reference numerals and the description thereof will be omitted.

FIG. 1 is a block diagram showing the configuration of a servo motor control device according to an embodiment of the present invention. In FIG. 1, a sine wave output unit 4 connected to a counter 3 that counts the A-phase and B-phase signals a from the incremental encoder 2 and outputs the count value as the electrical angle value of the servomotor 1 is used to calculate each phase current command. The electric angle value b1 from the counter 3, which is connected to the section 8, is used to form a sine wave output c1 from the electric angle value b1 and outputs the sinusoidal wave output c1 to each phase current command calculating section 8 and each phase current command calculating section 8 Then, based on the sine wave output c1 from the sine wave output unit 2 and the torque command f, each phase current command g
Calculate 1 and output.

On the other hand, the electrical angle determination unit 11 to which the encoder 2 is connected has a 3-bit three-phase (U,
The combination of (V, W) CS signals (three-phase commutation signals) is determined, and an intermediate value in the electrical angle range corresponding to the three-phase CS signals is output. In addition, the edge detection unit 12 to which the encoder 2 is connected is the U phase C from the encoder 2.
The U-phase edge of the S signal (U-phase commutation signal) is detected, and the electrical angle corresponding to the U-phase edge is output. Furthermore, the electrical angle offset output unit 13 synchronizes the electrical angle offset signal corresponding to the phase difference between the U-phase inter-phase induced voltage and the U-phase CS signal from the encoder 2, that is, the U-phase inter-phase voltage and the U-phase CS signal. When the motor 1a is used, it outputs an electrical angle offset signal of 0 °, and when the motor 1b in which the U-phase line voltage and the U-phase CS signal are synchronized, it is 30 °.
Minute electrical angle offset signal is output.

Furthermore, the electrical angle initial setting unit 14 to which the electrical angle determination unit 11 and the electrical angle offset output unit 13 are connected.
Is connected to the counter 3 and the electric angle determination unit 11 is turned on when the power is turned on.
The counter 3 is initialized to an addition value of the electrical angle of the output and the electrical angle offset signal from the electrical angle offset output unit 13. Further, the electrical angle resetting unit 15, to which the edge detecting unit 12 and the electrical angle offset output unit 13 are connected, detects the electrical angle of the output from the edge detecting unit 12 when the U-phase edge of the U-phase CS signal is detected. The added value with the electrical angle offset signal from the electrical angle offset output unit 13 is reset in the counter 3.

Servo motor control constructed as described above
The operation of the device will be described below. Figure 2
In the servo motor control device of No. 1, U-phase interphase voltage and U-phase
The torque in the CW direction drives the motor 1a with which the phase CS signal is synchronized.
It is a waveform diagram of each main part when rotated in the CW direction,
Is the motor output torque waveform, B is the counter value (electrical angle value)
Waveform, C is each phase current waveform, and D is each phase CS signal waveform
Is shown. The time point m and time point n shown in FIG.
At the time when the signal d changes, time k is the time when the power is turned on. Well
Also, the U-phase CS signal edge detection is only for the rising edge.
Should be detected, and the first rising edge after power is turned on.
J is the time point p. Furthermore, when the power is turned on, each phase CS signal
Range of electrical angle (time point m
~ Intermediate value (electrical angle at time point n) (electrical angle at time point r) and 0 °
Set the added value of the minute electrical angle offset to the counter 3
And count the A-phase and B-phase signal a starting from this
Detects the first rising edge of the U-phase CS signal
The sine wave is output during the period (the shaded area S in FIG.₁, S ₂, S₃) C1
Can be formed. The phase of the sine wave in this case is
Deviation of up to 30 ° from the phase of the sine wave that should be
I don't have it. In addition, the deviation is due to the rise of the U-phase CS signal.
It is constant during detection of the rising edge, and the motor 1a
The output torque also becomes constant.

Further, at the time point p at which the first rising edge of the U-phase CS signal is detected after the power is turned on, the accurate electrical angle is known, and the added value of the value and the electrical angle offset signal of 0 ° is returned to the counter 3. After setting, the motor 1a is driven with a sine wave that should be present thereafter.

FIG. 3 shows a motor 1 in which the U-phase line voltage and the U-phase CS signal are synchronized in the servo motor control device of FIG.
It is a waveform diagram of each main part when b is rotated in the CW direction with a torque in the CW direction. A is a motor output torque waveform, B is a counter value (electrical angle value) waveform, C is a phase current waveform, and D shows the CS signal waveform of each phase. As shown in FIG. 3, the only difference from that described in FIG. 2 is that the value of the electrical angle offset signal is 30 °, and the other points are the same as those described in FIG.

[0018]

As described above, according to the present invention, the sine wave is generated even during the drive control of the servo motor using the counter set value by the electric angle initial setting unit until the counter is reset by the electric angle resetting unit. The output torque of the servo motor can be made constant by the output, and occurs when a motor in which the U-phase line voltage and the U-phase CS signal are synchronized as in the conventional case is used.
It is possible to solve the problem that the servo gain cannot be increased due to resonance due to the output torque fluctuation of the motor, and the motor in which the U-phase interphase voltage and the U-phase CS signal are synchronized,
It can be applied to any motor in which the U-phase line voltage and the U-phase CS signal are synchronized.

[Brief description of drawings]

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

FIG. 2 is a waveform diagram of each main part when the motor 1a in which the U-phase interphase voltage and the U-phase CS signal are synchronized is rotated in the CW direction by the torque in the CW direction in the servo motor control device of FIG. A is a motor output torque waveform, B is a counter value (electrical angle value) waveform, C is a current waveform of each phase, and D is a CS signal waveform of each phase.

FIG. 3 is a waveform diagram of main parts when the motor 1b in which the U-phase line voltage and the U-phase CS signal are synchronized is rotated in the CW direction by the torque in the CW direction in the servo motor control device of FIG. , A is a motor output torque waveform, B is a counter value (electrical angle value) waveform, C is a current waveform of each phase, and D is a CS signal waveform of each phase.

FIG. 4 is a block diagram showing a configuration of a conventional servo motor control device.

FIG. 5 is a waveform diagram of main parts when the motor 1a in which the U-phase interphase voltage and the U-phase CS signal are synchronized is rotated in the CW direction with a torque in the CW direction in the servo motor control device of FIG. A is a motor output torque waveform, B is a counter value (electrical angle value) waveform, C is a current waveform of each phase, and D is a CS signal waveform of each phase.

FIG. 6 is a waveform diagram of each main part when the motor 1b in which the U-phase line voltage and the U-phase CS signal are synchronized is rotated in the CW direction with the torque in the CW direction in the servo motor control device of FIG. , A is a motor output torque waveform, B is a counter value (electrical angle value) waveform, C is a current waveform of each phase, and D is a CS signal waveform of each phase.

[Explanation of symbols]

 1, 1a, 1b Servo motor 2 Encoder 3 Counter 4 Sine wave output unit 8 Each phase current command calculation unit 9 Each phase current control unit 10 PWM inverter unit 11 Electrical angle determination unit 12 Edge detection unit 13 Electrical angle offset output unit 14 Electrical Angle initial setting section 15 Electric angle resetting section

Claims (1)

[Claims] 1. A servomotor control device for driving and controlling a servomotor provided with an incremental encoder according to a current command calculated from a sine wave output and a torque command, wherein an A phase B phase signal from the incremental encoder is input. A counter for counting and outputting the electrical angle value of the alternating current flowing through the servo motor, a sine wave output section for outputting the sine wave output with the electrical angle value of the counter output as an input, and a communicator output by the incremental encoder. Rotation signal as an input and an electrical angle determination unit that outputs an electrical angle value corresponding to the commutation signal, and a U-phase edge of the commutation signal is detected, and an electrical angle value corresponding to the U-phase edge is output. The edge detector, the U-phase interphase induced voltage, and the incremental encoder An electrical angle offset output unit that outputs an electrical angle offset corresponding to a phase difference with a phase commutation signal, and the counter that sums the electrical angle value of the output of the electrical angle determination unit and the electrical angle offset when the power is turned on. And an electrical angle for resetting the added value of the electrical angle value of the output of the edge detection unit and the electrical angle offset when the U-phase edge of the commutation signal is detected. A servo motor control device including a resetting unit.