Frequency-response measurement device

Patent metadata

Field	Value
Publication number	US-2016123796-A1
Application number	US-201314895008-A
Country	US
Kind code	A1
Filing date	Jun 3, 2013
Priority date	Jun 3, 2013
Publication date	May 5, 2016
Grant date	—

Abstract

A frequency-response measurement device according to an embodiment of the present invention measures a frequency response of a servo system that executes feedback control of a mechanical system. The frequency-response measurement device includes an excitation-condition setting unit that sets a plurality of different excitation conditions, an excitation execution unit that executes the multiple excitations with respect to the servo system by using excitation signals with the different excitation conditions, and a frequency-response calculation unit that acquires a pair of identification input signal and identification output signal for each of the multiple excitations, from a control system of the servo system on which the multiple excitations are performed, and calculates the frequency response based on the excitation conditions for each of the multiple excitations and the pair of identification input signal and identification output signal.

First claim

1 . A frequency-response measurement device that measures a frequency response of a servo system that executes feedback control of a mechanical system, the frequency-response measurement device comprising:
an excitation-condition setting unit to set a plurality of different excitation conditions; an excitation execution unit to execute multiple excitations with respect to the servo system by using excitation signals with the different excitation conditions; and a frequency-response calculation unit to acquire a pair of identification input signal and identification output signal for each of the multiple excitations, from a control system of the servo system on which the multiple excitations has been performed, and to calculate the frequency response based on the excitation condition for each of the multiple excitations and the pair of identification input signal and identification output signal, wherein the excitation condition is excitation amplitude which is amplitude of the excitation signal, and wherein the frequency-response calculation unit includes an each-time frequency-response calculation unit to calculate a frequency response for each of the multiple excitations, based on the pair of identification input signal and identification output signal for each of the multiple excitations, and a frequency-response synthesis unit to calculate the frequency response based on the frequency response for each of the multiple excitations and the excitation condition.

2 - 3 . (canceled)

4 . The frequency-response measurement device according to claim 1 , wherein
the excitation-condition setting unit sets first excitation amplitude and second excitation amplitude different from the first excitation amplitude as the excitation amplitude, and the frequency-response synthesis unit calculates, as the frequency response, a value of a fractional expression having a denominator and a numerator, wherein the denominator is a difference between a ratio of the first excitation amplitude to the frequency response for each of the multiple excitations at the first excitation amplitude and a ratio of the second excitation amplitude to the frequency response for each of the multiple excitations at the first excitation amplitude, and the numerator is a difference between the first excitation amplitude and the second excitation amplitude.

5 . The frequency-response measurement device according to claim 1 , wherein the excitation signal is applied to a speed command of the control system, and a position command applied to the control system has a constant value under the different excitation conditions.

6 . The frequency-response measurement device according to claim 1 , wherein the pair of identification input signal and identification output signal constitutes an open loop in the control system.

7 . The frequency-response measurement device according to claim 6 , wherein the identification input signal is a torque command signal of the servo system and the identification output signal is a speed signal of the servo system.

8 . The frequency-response measurement device according to claim 6 , wherein the identification input signal is a speed deviation signal of the servo system and the identification output signal is a speed signal of the servo system.

Assignees

• Mitsubishi Electric Corp

Inventors

• Nagaoka Kotaro
• Fujita Tomoya
• Ozawa Masahiro

Classifications

• G01H1/003 Primary

  of rotating machines (G01H1/10 takes precedence) · CPC title

• G05B19/4062 Primary

  Monitoring servoloop, e.g. overload of servomotor, loss of feedback or reference · CPC title