JPH10332798A - Method and device for measuring motor frequency characteristic and method and device for motor control - Google Patents

Abstract

PROBLEM TO BE SOLVED: To start the control of a motor after rapidly and easily measuring the frequency characteristics of the motor and bringing a control system into an optimum condition automatically. SOLUTION: A control circuit 8 sets switches SW1 and SW2 to a terminal (a) side. A motor drive circuit 1 supplies a power according to M-series signals 90 input from an M-series generating circuit 7 to a motor 2 so as to rotate the motor 2. A high-speed Fourier conversion circuit 4 performs a high speed Fourier conversion of a voltage 70 according to the rotating speed of the motor 2 input from a frequency voltage conversion circuit 3. Also a calculation circuit 5 obtains the frequency characteristics of the motor 2 from the high speed Fourier conversion data 80, and sets the gain of an amplifier 6 depending on the magnitude of the gain. Then the control circuit 8 sets the switches SW1 and SW2 to a terminal (b) side. The motor drive circuit 1 supplies a power to the motor 2 so that speed error voltage 50 input form the amplifier 6 becomes zero so as to rotate the motor 2 at a target speed specified by a reference voltage Vref.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and an apparatus for measuring the frequency characteristics of a motor for measuring the frequency characteristics of the motor in order to optimally adjust the control system, and to optimally adjust the speed control system of the motor. The present invention relates to a motor control method and apparatus for starting motor speed (rotation speed) control.

[0002]

2. Description of the Related Art Conventionally, in a motor control device for controlling the rotation speed of a motor by a speed control system, the speed of the motor is controlled after the speed control system (particularly, the transfer characteristics of the motor) is optimally adjusted. Optimal adjustment of the transfer characteristics of the motor is equivalent to measuring the frequency characteristics of the motor and adjusting the frequency characteristics optimally.

In order to measure the frequency characteristics of a motor, a voltage for measurement is supplied to a drive circuit of the motor instead of a speed error voltage (same as an error signal) for controlling the rotation speed of the motor, and the motor is rotated. Is done. At this time, the rotation speed (frequency) of the motor was changed by manually changing the voltage for measurement, and a speed signal corresponding to the rotation speed of the motor at that point had to be measured for each point. Also, even if the frequency characteristics of the motor are optimally adjusted as described above, the state of the set having the motor control device, that is, variation or aging of the amplifier or the motor of the motor control device, or environmental conditions, etc. The control system sometimes deviated from the optimum frequency characteristic.

[0004]

As described above, in the conventional method for measuring the frequency characteristics of a motor, a voltage for measurement is manually changed, and a speed signal corresponding to the motor speed at that time is provided for each point. There has been a problem that the measurement has to be performed, which takes time and effort. Also, even if the frequency characteristics of the motor are measured and the speed control system of the motor is adjusted optimally, the control system deviates from the optimal frequency characteristics due to the state of the set having the motor,
At the stage of actual use, it is not the optimal control system,
There was a problem that the control performance as designed could not be obtained.

The present invention has been made in view of such a situation, and a method and apparatus for measuring the frequency characteristics of a motor, which can quickly and easily measure the frequency characteristics of the motor, and a control system are automatically provided. It is an object of the present invention to provide a motor control method and apparatus for starting motor control in an optimum state.

[0006]

According to a first aspect of the present invention, there is provided a motor frequency characteristic measuring method for measuring a frequency characteristic of a motor constituting a speed control system. Inputting an M-sequence signal to the motor drive circuit in place of the error signal to be controlled to obtain a speed signal corresponding to the rotation speed of the motor; and analyzing the obtained speed signal to obtain a frequency characteristic of the motor. And a step of measuring.

According to a second aspect of the present invention, the frequency characteristic of the motor is converted into a voltage corresponding to the frequency, and the obtained voltage is subjected to a fast Fourier transform to measure the frequency characteristic of the motor.

According to a third aspect of the present invention, there is provided a motor frequency characteristic measuring apparatus for measuring a frequency characteristic of a motor constituting a speed control system. Means, and inputting the M-sequence signal generated by the M-sequence signal generation means to a drive circuit of the motor instead of an error signal for controlling the rotation speed of the motor, and outputting a speed signal corresponding to the rotation speed of the motor. And a measuring unit for analyzing a speed signal obtained by the signal obtaining unit and measuring a frequency characteristic of the motor.

According to a fourth aspect of the present invention, there is provided a motor control method for controlling a rotation speed of a motor by a speed control system, the method comprising measuring a frequency characteristic of the motor using an M-sequence signal. Comparing the gain of the frequency characteristic of the motor with a predetermined standard gain, and setting an amplification gain of an error signal for controlling the rotation speed of the motor in the speed control system according to the comparison result. And setting a rotational speed control of the motor after setting an amplification gain of the error signal.

According to a fifth aspect of the present invention, in the motor control method, the step of measuring the frequency characteristic of the motor using the M-sequence signal includes: transmitting the M-sequence signal to a driving circuit of the motor; Obtaining a voltage corresponding to the rotation speed of the motor by inputting instead of an error signal for controlling the motor, and performing a fast Fourier transform on the obtained voltage, and calculating a gain of a frequency characteristic of the motor from the obtained conversion data. And the step of performing.

According to a sixth aspect of the present invention, there is provided a motor control device for controlling a rotation speed of a motor by a speed control system, wherein: an M-sequence signal generation means for generating an M-sequence signal; Measuring means for measuring the frequency characteristic of the motor using the M-sequence signal generated by the method, and comparing the gain of the frequency characteristic of the motor measured by the measuring means with a predetermined standard gain Means, setting means for setting an amplification gain of an error signal for controlling the rotation speed of the motor in the speed control system according to a comparison result of the comparing means,
And control means for starting rotation speed control of the motor after setting the amplification gain of the error signal by the setting means.

FIG. 1 is a functional block diagram showing an embodiment of a motor control device according to the present invention. Reference numeral 1 denotes a motor drive circuit (driver) for adjusting the power supplied to the motor 2 so that the input speed error voltage 50 becomes zero. Reference numeral 2 denotes a motor to be controlled, which is driven by the motor drive circuit 1 to rotate. I do. Reference numeral 3 denotes a frequency / voltage conversion circuit attached to the motor 2 for converting the frequency of a speed signal 60 obtained from a speed detector (FG) (not shown) for detecting the rotation speed of the motor 2 into a corresponding voltage 70. A fast Fourier transform circuit (FFT) 5 that performs fast Fourier transform on the voltage 70 input from the voltage transform circuit 3 via the switch SW2, and 5 is a gain of the frequency characteristic of the motor 2 calculated from the transform data 80 of the fast Fourier transform circuit 4. An arithmetic circuit for setting the gain of the amplifier 6 according to the magnitude. The arithmetic circuit 6 compares a reference voltage Vref for designating a target speed with a voltage input from the frequency / voltage conversion circuit 3 via the switch SW2, and determines a difference between the reference voltage Vref and the speed error voltage. An amplifier which outputs the signal to the terminal b of the switch SW2 as 50, a signal M of the characteristic M series is generated, and the terminal M-sequence generation circuit for outputting, 8 is a control circuit which controls the switching of switches SW1, SW2, performs the adjustment mode of the speed control system, the control of switching the speed control mode of the motor 2.

Next, the operation of this embodiment will be described. First, measurement candidates for the frequency characteristics of the motor 2 will be described. In this example, a known M-sequence signal is input to a device under test, and an output signal corresponding to the input signal is analyzed to measure the frequency characteristics of the device under test in one measurement operation. Utilizes the principle. Before starting the speed control of the motor 2, the control circuit 8 switches SW1,
SW2 is switched to the terminal a side, and the M-sequence generation circuit 7 generates the signal 90 of the characteristic M-sequence. At this time, the control circuit 8 activates the fast Fourier transform circuit 4 and the arithmetic circuit 5. Thereby, the signal of the characteristic M series is input to the motor drive circuit 1 via the switch SW1. The motor drive circuit 1 supplies power corresponding to the signal 90 of the characteristic M series to the motor 2 to rotate the motor 2. At this time, the rotation speed (rotation speed) of the motor 2 changes according to the signal of the characteristic M series. The rotation speed of the motor 2 is detected by a speed detector (not shown) as a speed signal 60 having a frequency corresponding to the rotation speed, and the speed signal 60 is converted by the frequency / voltage conversion circuit 3 to the frequency (rotation speed of the motor 2). It is converted to the corresponding voltage 70. The voltage 70 output from the frequency / voltage conversion circuit 3 is input to the fast Fourier conversion circuit 4 via the switch SW2.

The fast Fourier transform circuit 4 transforms the input voltage (corresponding to the rotation speed of the motor 2) 70 into a frequency domain data 80 by performing a fast Fourier transform, and outputs this to the arithmetic circuit 5. The arithmetic circuit 5 calculates the gain of the frequency characteristic of the motor 2 based on the input data 80, and compares the obtained gain of the frequency characteristic of the motor 2 with the gain of the preset design standard characteristic.

As a result of this comparison, if the gain of the frequency characteristic of the motor 2 is smaller than the gain of the design standard characteristic, the arithmetic circuit 5 sets the gain of the amplifier 6 so as to increase the gain of the amplifier 6 by the difference. I do. When the gain of the frequency characteristic of the motor 2 is larger than the gain of the design standard characteristic, the arithmetic circuit 5 sets the gain of the amplifier 6 so as to reduce the gain of the amplifier 6 by the difference.

Thereafter, the control circuit 8 switches SW1, S
While switching W2 to the terminal b side, the operations of the M-sequence generation circuit 7, the fast Fourier transform circuit 4 and the arithmetic circuit 5 are stopped, and the speed control of the motor 2 is started. Thereby, the motor 2 is rotated by the electric power supplied from the motor drive circuit 1. The rotation speed of the motor 2 at this time is detected as a speed signal 60 by a speed detector (not shown),
The speed signal 60 is converted by the frequency / voltage conversion circuit 3 into a voltage 70 corresponding to the frequency of the speed signal 60 (corresponding to the rotation speed of the motor 2). The voltage 70 output from the frequency / voltage conversion circuit 3 is input to the + terminal of the amplifier 6.

On the other hand, the negative terminal of the amplifier 6 has a reference voltage Vr
ef has been input. For this reason, the difference between the two voltages is obtained in the amplifier 6, and the difference is further amplified by the set gain to become the speed error voltage 50 and input to the motor drive circuit 1. The motor drive circuit 1 adjusts the power supplied to the motor 2 so that the input speed error voltage 50 becomes zero.
Rotate at the target speed specified by ref.

FIG. 2 is a flowchart showing a procedure for measuring the frequency characteristics of the motor 2 described above. Step 201
, An M-sequence signal 90 output from the M-sequence generation circuit 7
Is input to the motor drive circuit 1 to drive the motor 2 to obtain a speed signal 60 corresponding to the rotation speed of the motor 2. At step 202, the speed signal 6 corresponding to the rotation speed of the motor 2
0 is converted into a voltage 70 corresponding to the rotation speed by the frequency-voltage conversion circuit 3, and the voltage 70 is Fourier-transformed by the high-speed Fourier conversion circuit 4. In step 203, the gain of the frequency characteristic of the motor 2 is calculated from the Fourier transform data 80 of the Fourier transform circuit 4, and the gain of the amplifier 6 is set according to the magnitude of the gain.

FIG. 3 is a flowchart showing the operation procedure of the motor control device shown in FIG. In step 301, the control circuit 8 sets the switches SW1 and SW2 to the terminals a.
After switching to the side, the frequency characteristic of the motor 2 is measured, and the gain of the amplifier 6 is set based on the measurement result. At step 302, the switches SW1 and SW
After switching the terminal 2 to the terminal b, the speed control of the motor 2 is started.

According to the present embodiment, the frequency characteristic of the motor 2 is measured using the characteristic M-sequence signal 90. Therefore, the frequency characteristic of the motor 2 can be measured quickly and easily by one measurement operation. can do. Also, an M-sequence generation circuit 7 is built in the control system of the motor 2, and before starting the speed control of the motor 2, a characteristic M-sequence signal 90 generated from the M-sequence generation circuit 7 is transmitted to the drive circuit of the motor 2. 1, the frequency characteristic of the motor 2 is measured, and the gain of the amplifier 6 constituting the loop of the speed control system is adjusted according to the magnitude of the gain of the measured frequency characteristic, so that the speed control system is designed as designed. It can be adjusted to an optimal state. For this reason, the speed of the motor 2 can always be controlled with the designed performance regardless of the set state or the secular change of the motor 2 or the like.

[0021]

As described above, according to the motor frequency characteristic measuring method and apparatus of the present invention, the frequency characteristic of the motor can be measured quickly and easily. Further, according to the motor control method and apparatus of the present invention, it is possible to automatically start the control of the motor with the control system in an optimum state, regardless of the set state and the secular change of the motor. Speed control can always be performed with the designed performance.

[Brief description of the drawings]

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

FIG. 2 is a flowchart showing a procedure for measuring frequency characteristics of the motor shown in FIG. 1;

FIG. 3 is a flowchart showing an operation procedure of the motor control device shown in FIG. 1;

[Explanation of symbols]

1 motor drive circuit, 2 motors, 3 frequency / voltage conversion circuit, 4 fast Fourier transform circuit (FFT),
5 operation circuit, 6 amplifier, 7 M-sequence generation circuit, 8 control circuit

Claims (6)

[Claims] 1. A motor frequency characteristic measuring method for measuring a frequency characteristic of a motor constituting a speed control system, wherein an M-sequence signal is supplied to a driving circuit of the motor instead of an error signal for controlling a rotation speed of the motor. A method for measuring the frequency characteristics of a motor, comprising: a step of inputting a speed signal corresponding to a rotation speed of a motor, and a step of analyzing the obtained speed signal to measure a frequency characteristic of the motor. 2. The motor according to claim 1, wherein the speed signal is converted into a voltage corresponding to the frequency, and the obtained voltage is subjected to a fast Fourier transform to measure a frequency characteristic of the motor. Frequency characteristic measurement method. 3. A motor frequency characteristic measuring device for measuring a frequency characteristic of a motor constituting a speed control system, comprising: an M-sequence signal generating means for generating a characteristic M-sequence signal; A signal acquisition unit that inputs the M-sequence signal to a drive circuit of the motor instead of an error signal that controls the rotation speed of the motor, and obtains a speed signal corresponding to the rotation speed of the motor; Measuring means for analyzing the speed signal obtained and measuring the frequency characteristic of the motor, wherein the frequency characteristic of the motor is measured. 4. A motor control method for controlling the rotation speed of a motor by a speed control system, comprising: measuring a frequency characteristic of the motor using an M-sequence signal; Comparing the gain with a standard gain set in advance; setting an amplification gain of an error signal for controlling a rotation speed of the motor in the speed control system according to the comparison result; and amplifying the error signal. Starting the rotation speed control of the motor after setting the gain. 5. The step of measuring a frequency characteristic of the motor using the M-sequence signal includes inputting the M-sequence signal to a drive circuit of the motor instead of an error signal for controlling a rotation speed of the motor. Obtaining a voltage corresponding to the rotation speed of the motor, and performing a fast Fourier transform of the obtained voltage, and calculating a gain of a frequency characteristic of the motor from the obtained conversion data. The motor control method according to claim 4, wherein 6. A motor control device for controlling a rotation speed of a motor by a speed control system, comprising: an M-sequence signal generation means for generating an M-sequence signal; and an M-sequence signal generated by the M-sequence signal generation means. Measurement means for measuring the frequency characteristic of the motor using: a comparison means for comparing the gain of the frequency characteristic of the motor measured by the measurement means with a preset standard gain; and a comparison result of the comparison means Setting means for setting an amplification gain of an error signal for controlling the rotation speed of the motor in the speed control system according to the following.After setting the amplification gain of the error signal by the setting means, controlling the rotation speed of the motor. A motor control device comprising: a control unit that starts the motor control.