JP2952276B2 - Device for measuring torque characteristics of stepping motors - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring characteristics of a stepping motor.

[0002]

2. Description of the Related Art A stepping motor has various electronic control features, such as good response of start / stop / forward / reverse rotation, accurate rotation angle, and self-holding of the rotation angle. Widely used for equipment. Therefore, it is necessary to measure the characteristics of the stepping motor from the viewpoint of product test of the stepping motor.

[0003]

It is particularly important to know the pull-out characteristic and the pull-in characteristic among the characteristics of such a stepping motor. However, in the conventional measurement of this type of characteristic, the step-out state is confirmed by using a method such as detecting a mark attached to the motor shaft by a rotation detection sensor, which is inconvenient for measurement and short. High-precision measurement results cannot be obtained in time. Therefore, when applied to a stepping motor production line, these characteristics, the maximum self-start frequency f ₁ , the maximum response
Techniques for measuring the wave number f ₂ has not yet been proposed.

An object of the present invention is to provide a torque characteristic measuring device for a stepping motor capable of measuring a pull-in characteristic and a pull-out characteristic immediately and with high accuracy.

[0005]

In order to achieve this object, a torque characteristic measuring apparatus for a stepping motor according to the present invention comprises: a driving means for changing a repetition frequency of a driving pulse of a stepping motor to be measured; containing the waveform of the values of the function and the torque calculation unloading of the value of the torque to be measured stepping motor corresponding to the repetition frequency
The fundamental wave component included is the repetition frequency of the drive pulse and
When there is a correlation, the stepping motor to be measured
The control means has a function of determining that the motor is in a tuning state, and a display means for displaying a characteristic of a torque value of the stepping motor to be measured and a repetition frequency of the drive pulse.

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 1 shows an embodiment of the present invention. In this embodiment, 1 is a stepping motor to be measured and 2 is a CPU.
Such control unit, 3 a drive unit for driving the stepping motor 1 by the driving pulse repetition frequency corresponding to the frequency command C _f from the control unit 2, 4 is a DC power source for supplying a direct current to the driving unit 3. Reference numeral 5 denotes a display unit such as a CRT, and 6 denotes a recording unit such as a floppy disk. 1a is a control stepping motor, 7 is a guide rail connected to the axis of the control stepping motor 1a, 10a is a load cell connected to this guide rail 7, 8 is an axis of the stepping motor 1 to be measured as required during testing. The pulley 10b to be arranged is a load cell, and the load cell 10b
The yarn 9 is stretched between the and 10a while being wound around the pulley 8 as shown. The driving unit 3 includes drivers 3a and 3b for driving the stepping motors 1 and 1a, respectively.
There is. Each output of the load cells 10b and 10a is connected to an amplifier l.
The signal is input to the differential amplifier 12 via la and 11b, and the output is input to the control unit 2.

[0007] In such a measuring apparatus, the external load torque applied to the shaft of the measurement stepping motor 1 drives the control stepping motor 1a, it is possible Rukoto varied by varying the tension of the thread 9 . or,
At this time, the torque value applied to the axis of the stepping motor 1 to be measured is the difference between the torque values of the load cells 10a and 10b, that is, the output value of the operation amplifier 12, and the control unit 2 uses the data as an average value.

[0008] This way, the determined pull characteristics and the pull-out characteristics are shown in FIG. 2, the measurement result is shown in FIG 3.

The torque value in the synchronous operation state is shown in FIG.
As shown in (b), the value is substantially constant. For example, if the positive value is the rotation in the CW direction, the negative value is the rotation in the CCW direction, and the rotation direction is also known. FIG. 5 shows the measurement results.

However, when the motor is out of synchronization, the motor cannot rotate normally as shown in FIG. FIG. 7 shows the measurement results. Experimental results have shown that the fundamental wave of this vibration frequency has a correlation with the drive frequency of the stepping motor to be measured.

In this embodiment, focusing on this, the waveform of the torque value obtained by the control
(Fast Fourier Transform) analyzed by analysis software with, divided into a harmonic component and a fundamental component, and the fundamental frequency, with out-of if there is compared to correlate the driving frequency of the measurement stepping motor It turns out there is .

[0012]

As described above in detail, according to the present invention, the most important pull-in characteristics and pull-out characteristics among the operation characteristics of the stepping motor can be measured immediately and easily with high accuracy. In particular, the present invention can be applied to a stepping motor production line and exert a great effect on quality control.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a characteristic diagram for explaining the operation of the embodiment of FIG.

FIG. 3 is an actual measurement characteristic diagram according to the embodiment of FIG. 1;

FIG. 4 is a characteristic diagram for explaining the operation of the embodiment of FIG. 1;

FIG. 5 is an actual measurement characteristic diagram according to the embodiment of FIG. 1;

FIG. 6 is a characteristic diagram for explaining the operation of the embodiment in FIG. 1;

FIG. 7 is an actual measurement characteristic diagram according to the embodiment of FIG. 1;

[Explanation of symbols]

 Reference Signs List 1 measurement stepping motor 1a control stepping motor 2 control unit 3a, 3b driving unit (driver) 4 DC power supply 5 display unit 6 recording unit 7 guide rail 8 pulley 9 thread 10a, 10b load cell 11a 11b amplifier 12 differential amplifier

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H02P 8/00-8/42 G01L 5/00 G01R 31/34

Claims (1)

(57) [Claims] 1. A driving means for changing the repetition frequency of the drive pulses of the measured stepping motor, the function of calculation and out of the value of the torque of the measured stepping motor corresponding to the repetition frequency of the drive pulse and the torr
The fundamental wave component included in the waveform of the
When the measured step has a correlation with the repetition frequency,
Torque characteristic measurement of a stepping motor, comprising: control means having a function of determining that the ping motor is out of synchronization; and display means for displaying a characteristic of a torque value of the stepping motor to be measured versus a repetition frequency of the drive pulse. apparatus.