KR20230047595A - fault diagnosis apparatus of actuator based on motor - Google Patents

Abstract

The present invention relates to a fault diagnosis apparatus for a motor-based controller, comprising: a current detection unit which detects current of an electric motor of a controller that controls a device to be controlled by rotation of the electric motor; a vibration sensor unit which detects vibration generated from the electric motor; a sound detection unit which detects sound generated by the controller; an FFT conversion unit which converts each of a signal output from the current detection unit, a signal output from the vibration sensor unit, and a signal output from the sound detection unit into a frequency domain; and a fault diagnosis unit which diagnoses a failure by comparing the signal generated in the FFT conversion unit with a failure determination standard model and provides diagnosis result information to a diagnosis management server through a communication unit. According to the fault diagnosis apparatus for a motor-based controller, the efficiency and precision of fault diagnosis can be improved by using the vibration, sound, and current signals in combination.

Description

Fault diagnosis apparatus of motor-based controller {fault diagnosis apparatus of actuator based on motor}

The present invention relates to a fault diagnosis apparatus for a motor-based controller, and more particularly, to a fault diagnosis apparatus for a motor-based controller capable of diagnosing a fault using a sensing signal including a vibration signal generated from a motor.

This study was conducted by a project supported by the '2021 Jangseong-gun Star Enterprise Development Project' of Jeonnam Technopark with funds from Jangseong-gun.

Electric motors are used to configure various controllers in industrial settings. As an example, in a water purification plant or sewage and wastewater treatment plant, a valve device that opens and closes a flow path based on a motor in a water treatment process for treating water or treating sewage and wastewater while transferring treated water stored in a treated water storage tank through a treated water transfer path It is applied. Such a valve device is constructed in various ways, such as an electric motor and a power repeater for relaying power so that the power generated by the motor rotates a valve plate that opens and closes a flow path. However, accidents such as interruption of water supply may occur when a component of the valve device fails or fails to operate.

Recently, failure diagnosis technology capable of preventing accidents due to such failures has emerged as an important part along with maintenance aspects.

Korean Patent Publication No. 10-2005-0063441 discloses a device for diagnosing an abnormal state of an induction motor. However, the diagnostic device has a disadvantage in that it is difficult to easily find an abnormal state due to noise for some low energy level failures such as bearing failures.

The present invention was invented to improve the above problems, and an object of the present invention is to provide a fault diagnosis device for a motor-based controller that can improve diagnosis efficiency for abnormal conditions.

In order to achieve the above object, a fault diagnosis device for a motor-based controller according to the present invention includes a current detector for detecting a current of the motor of a controller for controlling a controlled device by rotation of the motor; a vibration sensor unit for detecting vibration generated by the motor; a sound detection unit for detecting sound generated by the controller; an FFT conversion unit which converts each of the signal output from the current detection unit, the signal output from the vibration sensor unit, and the signal output from the sound detection unit into a frequency domain; and a failure diagnosis unit that compares the signal generated by the FFT conversion unit with a failure determination reference model to diagnose a failure, and provides diagnosis result information to a diagnosis management server through a communication unit.

Preferably, the vibration sensor unit includes a first vibration sensor for detecting a vibration signal in an axial direction of the electric motor; a second vibration sensor for detecting a vibration signal in a vertical direction perpendicular to the axial direction of the motor; and a third vibration sensor for detecting a vibration signal in a horizontal direction perpendicular to both the axial direction and the vertical direction of the motor.

In addition, the failure diagnosis unit is configured to transmit an emergency action message through the communication unit when it is determined that the sound data received from the sound detection unit through the FFT conversion unit contains a signal equal to or higher than a set reference level in a set failure area frequency band. can

According to one aspect of the present invention, the controller includes a power relay unit having a worm coupled to a shaft of the electric motor and a worm wheel meshed with the worm; and a valve plate that opens and closes the inside of the pipe in conjunction with the rotation of the worm wheel, and the sound detection unit is mounted on the power relay unit to detect sound generated from the power relay unit.

In addition, the failure diagnosis unit calculates a first diagnosis value by assigning a set first weight to first comparison result information obtained by comparing the first data output from the current detection unit and converted into a frequency domain with a current reference model for determining failure. and calculates a second diagnostic value by assigning a second weight set to the second comparison result information for non-exchange with the vibration reference model for determining failure to the second data output from the vibration sensor unit and converted to the frequency domain, It may be configured to determine a failure level from a sum of the first diagnosis value and the second diagnosis value, and to transmit the determined failure level information through the communication unit.

According to the fault diagnosis apparatus for a motor-based controller according to the present invention, the efficiency and precision of fault diagnosis can be improved by using vibration, sound, and current signals in combination.

1 is a diagram showing a fault diagnosis device for a motor-based controller according to the present invention.

Hereinafter, a fault diagnosis device for a motor-based controller according to a preferred embodiment of the present invention will be described in more detail with reference to the accompanying drawings.

1 is a diagram showing a fault diagnosis device for a motor-based controller according to the present invention.

Referring to FIG. 1 , the fault diagnosis apparatus 100 according to the present invention includes a current detection unit 110, a vibration sensor unit 120, a sound detection unit 130, an FFT conversion unit 140, and a failure diagnosis unit 150. provide

The controller 10 is exemplified as a valve device that controls a controlled device by rotation of an electric motor (M) 20 . The controller 10 includes an electric motor 20 driven by a driving unit 60, a worm 31 coupled to the shaft 22 of the electric motor 20, and a worm wheel 32 meshed with the worm 31. It is interlocked with the rotation of the rotation shaft 32a of the power relay unit 30 and the worm wheel 32 to open and close the flow path inside the pipe 40.

Of course, the controller 10 may have a structure in which an electric motor is applied to an operating structure different from the illustrated example.

The current detection unit 110 detects the current of the electric motor 20 . In the illustrated example, the current of each phase of the motor 20 supplied with the three-phase current is detected, and when a single-phase motor is applied, it is sufficient to detect the current flowing through one power supply line.

The current detector 110 may be applied with a low pass filter that removes and outputs a high frequency current component with respect to the measured current.

The vibration sensor unit 120 detects vibration generated from the electric motor 20 . In the vibration sensor unit 120, first to third vibration sensors 121 to 123 are applied so as to detect vibrations in three directions generated by the vibrator 20, respectively.

The first vibration sensor 121 is installed to detect an axial vibration signal of the electric motor 20 .

The second vibration sensor 122 is installed to detect a vertical direction vibration signal perpendicular to the axial direction of the motor 20 .

The third vibration sensor 123 is installed to detect a horizontal direction vibration signal perpendicular to both the axial direction of the motor 20 and the vertical direction, which is the vibration detection direction of the second vibration sensor 122 .

The first vibration sensor 121 is installed on the shaft 22 of the vibrator 20, the second vibration sensor 121 is installed on the housing of the motor 20 in a first direction orthogonal to the axial direction, and the third The vibration sensor 121 may be installed on the housing of the motor 20 in an axial direction and in a second direction orthogonal to the first direction.

The sound detection unit 130 is mounted on the power relay unit 30 to detect sound generated by the power relay unit 30 .

Of course, the sound detection unit 130 may additionally install an acoustic sensor for detecting sound corresponding to the position of the bearing of the motor 20 so as to receive sound generated from the bearing of the motor 20 .

The FFT conversion unit 140 includes current signals of each phase output from the current detection unit 110, vibration signals output from the first to third vibration sensors 121 to 123 of the vibration sensor unit 120, and a sound detection unit ( 130) converts each of the sound signals output into frequency domain data through a Fast Fourier Transform process.

The failure diagnosis unit 150 compares the data generated by the FFT conversion unit 140 with a failure determination reference model to diagnose whether there is a failure, and transmits the diagnosis result information to the diagnosis management server 200 through the communication unit 160 at a set period. provided every

As an example, the fault diagnosis unit 150 is the driving unit 60 when an inverter that supplies power by turning on/off of a plurality of switch elements is applied to the driving unit 60 and an induction motor is applied to the electric motor 20. If only a DC component exists in the signal output through the FFT conversion unit 140 after the high frequency current component detected by the current detector 110 as an input current is removed, normal operation is diagnosed. Unlike this, the fault diagnosis unit 150 diagnoses a failure when a specific alternating current component having a frequency exists in the direct current part of the input current of the driving part 60. That is, when the frequency of the current supplied to the stator of the motor 20 is fs and the frequency of the current flowing to the rotor is fr, the fault diagnosis unit 150 determines the current component having a frequency of 2 fs in the input current of the driving unit 60. If there exists, it can be constructed to diagnose a stator winding partial short-circuit failure, and to diagnose a rotor bar crack failure if a current component having a (1-2s) fs frequency exists in the input current of the drive unit 60.

Unlike this, the failure diagnosis unit 150 may be constructed to compare the first data output from the current detection unit 110 and converted to the frequency domain with a current reference model for determining failure, calculate a correlation related to fixing, and determine whether or not there is a failure. there is. Here, the current reference model can be applied to the current data set secured and recorded so that the normal state and the fault state can be compared and discriminated.

In addition, the failure diagnosis unit 150 is constructed to compare the 3-axis vibration data output from the vibration sensor unit 120 and output through the FFT conversion unit 140 with a vibration reference model for determining failure to diagnose failure. can Here, the vibration reference model for determining failure may apply a vibration data set recorded for vibration signals generated in each direction when a failure of the motor 20 occurs. Here, the vibration data set is recorded as combination reference data combining all 3-axis vibrations, and the fault diagnosis unit 150 combines the 3-axis vibration data output through the FFT conversion unit 140 according to a set combination method, and then combines It can be built to determine whether there is a failure by comparing with reference data.

In addition, the failure diagnosis unit 150 compares the first data output from the current detection unit 110 and converted into the frequency domain with the current reference model for determining failure, and assigns a first weight set to the first comparison result information to determine the first data. A first diagnosis value is calculated, and a second weight value set for the second comparison result information for non-exchange with the vibration reference model for determining failure is applied to the second data output from the vibration sensor unit 120 and converted to the frequency domain, so that a second weight value is applied. It may be configured to calculate a diagnostic value, determine a failure level from a sum of the first diagnostic value and the second diagnostic value, and transmit the determined failure level information through the communication unit 160 .

When it is determined that the sound data received from the sound detection unit 130 through the FFT conversion unit 140 includes a signal equal to or higher than the set reference level in the set failure area frequency band, the fault diagnosis unit 150 transmits through the communication unit 160. It can be configured to send an emergency action message. Here, the frequency of the failure area may be applied to the frequency of noise generated during meshing due to gear wear, and the reference level may be appropriately determined to the extent to be guided to immediately proceed with replacement repair.

Of course, the fault diagnosis unit 150 may be constructed to control the operation of the motor 20 by controlling the driving unit 60 according to the operation control signal received through the communication unit 160 .

The diagnosis management server 200 records the diagnosis result information received through the communication unit 160 as diagnosis history information in a database (not shown) corresponding to the unique identification information of the controller 10 to be diagnosed, and provides it for viewing, When an emergency notification is requested to the manager according to the received failure information, diagnosis information may be transmitted to the manager terminal (not shown).

According to the fault diagnosis apparatus for the motor-based controller described above, the efficiency and precision of fault diagnosis can be improved by using vibration, sound, and current signals in combination.

110: current detection unit 120: vibration sensor unit
130: sound detection unit 140: FFT conversion unit
150: fault diagnosis unit

Claims (5)

a current detection unit for detecting a current of the motor of a controller that controls a controlled device by rotation of the motor;
a vibration sensor unit for detecting vibration generated by the motor;
a sound detection unit for detecting sound generated by the controller;
an FFT conversion unit which converts each of the signal output from the current detection unit, the signal output from the vibration sensor unit, and the signal output from the sound detection unit into a frequency domain;
A fault diagnosis unit for comparing the signal generated by the FFT conversion unit with a failure determination reference model to diagnose a failure and providing diagnosis result information to a diagnosis management server through a communication unit. fault diagnosis device. The method of claim 1, wherein the vibration sensor unit
a first vibration sensor for detecting an axial vibration signal of the motor;
a second vibration sensor for detecting a vibration signal in a vertical direction perpendicular to the axial direction of the motor;
and a third vibration sensor for detecting a vibration signal in a horizontal direction perpendicular to both the axial direction and the vertical direction of the motor. The method of claim 2 , wherein the failure diagnosis unit transmits an emergency action message through the communication unit when it is determined that the sound data received from the sound detection unit through the FFT converter includes a signal equal to or higher than a set reference level in a set failure area frequency band. A fault diagnosis device for a motor-based controller, characterized in that to transmit. The method of claim 2, wherein the controller
a power relay unit having a worm coupled to the shaft of the motor and a worm wheel engaged with the worm;
A valve plate that opens and closes the inside of the pipe in conjunction with the rotation of the worm wheel;
The fault diagnosis device of the motor-based controller, characterized in that the sound detection unit is mounted on the power relay unit to detect the sound generated by the power relay unit. The method of claim 2, wherein the failure diagnosis unit
A first diagnosis value is calculated by assigning a first weight set to first comparison result information obtained by comparing the first data output from the current detector and converted into the frequency domain with a current reference model for determining failure, and calculating a first diagnosis value, and the vibration sensor unit A second diagnostic value is calculated by giving a second weight set for the second comparison result information that is not exchanged with the vibration reference model for determining failure to the second data output and converted into the frequency domain, and the first diagnostic value and the second diagnostic value are calculated. A fault diagnosis device for a motor-based controller, characterized in that it is constructed to determine a fault level from the sum of the second diagnosis values and to transmit the determined fault level information through the communication unit.

Images