KR102266220B1 - Fault Diagnosis System of Industrial Robot - Google Patents

Abstract

The present invention relates to an RV gearbox in which a crankshaft bearing of an industrial robot is installed, a sensor unit coupled to the RV gearbox and detecting vibration of the crankshaft bearing, and a vibration signal connected to the sensor unit and sensed by the sensor unit Failure of an industrial robot, characterized in that it comprises a failure diagnosis unit receiving a failure diagnosis unit, wherein the failure diagnosis unit determines whether the industrial robot has a failure by using at least one of a noise value and an amplitude modulation value of the vibration signal detected by the sensor unit It is about a diagnostic system.

Description

Fault Diagnosis System of Industrial Robot

The present invention relates to a failure diagnosis system for an industrial robot for diagnosing a failure of an industrial robot performing a manufacturing process for an object.

In general, ships, vehicles, construction machines, mobile phones, etc. (hereinafter referred to as 'objects') are manufactured by assembling various parts. For example, a process of manufacturing an object through manufacturing processes such as a welding process, a transfer process, and a painting process for parts constituting the object is performed. A plurality of industrial robots may be installed in a process line to perform the above-described manufacturing process.

These industrial robots are used as core equipment in various manufacturing processes such as equipment-intensive LCD manufacturing processes and high-density automobile manufacturing processes. Therefore, in recent years, there is an urgent need for a diagnostic system for a failure of an industrial robot.

The failure diagnosis system of an industrial robot according to the prior art diagnoses an abnormality of the robot from a current signal supplied to parts such as a motor without a separate sensor. Accordingly, the failure diagnosis system of the industrial robot according to the prior art has the following problems.

First, since the fault diagnosis system of the industrial robot according to the prior art diagnoses an abnormality using a current signal, when an abnormal current signal is sensed from one component, an abnormal current signal is generated from a number of related components. Accordingly, the fault diagnosis system of the industrial robot according to the prior art not only requires a separate technology to determine the part from which the abnormal current signal is initially generated, but also takes a long time to diagnose the fault and increases the cost.

Second, since the fault diagnosis system of the industrial robot according to the prior art uses a current signal to diagnose an abnormality, there is a problem in that the accuracy of fault diagnosis is deteriorated.

The present invention has been devised to solve the above-described problems, and an object of the present invention is to provide an industrial robot failure diagnosis system capable of quickly and accurately diagnosing a failure of the industrial robot.

In order to solve the problems as described above, the present invention may include the following configuration.

A failure diagnosis system for an industrial robot according to the present invention includes: an RV gearbox in which a crankshaft bearing of the industrial robot is installed; a sensor unit coupled to the RV gearbox and configured to sense vibration of the crankshaft bearing; and a failure diagnosis unit connected to the sensor unit and receiving the vibration signal sensed by the sensor unit. The failure diagnosis unit may determine whether the industrial robot has a failure by using at least one of a noise value and an amplitude modulation value of the vibration signal detected by the sensor unit.

In the failure diagnosis system of the industrial robot according to the present invention, the failure diagnosis unit uses the noise value of the vibration signal to determine the presence or absence of a failure of the industrial robot using a noise diagnosis mechanism, and the amplitude modulation value of the vibration signal Thus, it may include an amplitude modulation diagnosis mechanism for determining whether the industrial robot has a failure.

In the failure diagnosis system for an industrial robot according to the present invention, the noise diagnosis mechanism includes a noise aligning member for aligning acceleration values for each rotational direction of the crankshaft bearing, a noise extracting member for extracting acceleration values for each rotational direction, and the rotation A noise averaging member for deriving an average value for the acceleration values for each direction, a noise residual member for deriving a residual value by subtracting the average value derived by the noise averaging member from the acceleration values for each rotational direction extracted by the noise extracting member, and the noise residual A noise reference member for deriving a reference noise value by performing RMS on the residual value derived by the member may be included.

In the failure diagnosis system for an industrial robot according to the present invention, the noise diagnosis mechanism determines a failure when the noise value of the vibration signal detected by the sensor unit exceeds the reference noise value, and the noise value of the vibration signal is the reference value. If it is below the noise value, it can be determined as normal.

In the failure diagnosis system for an industrial robot according to the present invention, the amplitude modulation diagnosis mechanism includes an amplitude modulation alignment member for aligning acceleration values for each rotational direction of the crankshaft bearing, and amplitude modulation frequency analysis for analyzing frequency values for each rotational direction. It may include a member, and an amplitude modulation reference member for deriving a reference amplitude modulation value by performing RVF with the frequency value analyzed by the amplitude modulation frequency analysis member.

In the failure diagnosis system for an industrial robot according to the present invention, the amplitude modulation diagnosis mechanism determines a failure when the amplitude modulation value of the vibration signal sensed by the sensor unit exceeds the reference amplitude modulation value, and modulates the amplitude of the vibration signal If the value is equal to or less than the reference amplitude modulation value, it may be determined as normal.

According to the present invention, the following effects can be obtained.

The present invention is implemented to diagnose the failure of the industrial robot using the sensor installed in the RV gearbox, so that it is possible to quickly and accurately diagnose the failure of the industrial robot and minimize the delay in the manufacturing process.

1 and 2 are schematic block diagrams of a failure diagnosis system of an industrial robot according to the present invention.
3 is a schematic block diagram for explaining a noise diagnosis mechanism in a failure diagnosis system of an industrial robot according to the present invention;
4 to 7 are schematic views for explaining that the noise diagnosis mechanism derives the reference noise value in the failure diagnosis system of the industrial robot according to the present invention;
8 is a schematic block diagram for explaining an amplitude modulation diagnosis mechanism in a failure diagnosis system of an industrial robot according to the present invention;
9 to 11 are schematic views for explaining that the amplitude modulation diagnosis mechanism derives the reference amplitude modulation value in the failure diagnosis system of the industrial robot according to the present invention;
12 is a failure sensitivity graph measured by the failure diagnosis system of an industrial robot according to the present invention at a rotation speed of 50 deg/sec of a crankshaft bearing for each rotational direction
13 is a failure sensitivity graph measured by the failure diagnosis system of the industrial robot according to the present invention at a rotation speed of 100 deg/sec of the crankshaft bearing for each rotational direction

It should be noted that, in the present specification, in adding reference numbers to the components of each drawing, the same numbers are used for the same components, even if they are indicated on different drawings, as much as possible.

On the other hand, the meaning of the terms described in this specification should be understood as follows.

The singular expression is to be understood as including the plural expression unless the context clearly defines otherwise, and the terms "first", "second", etc. are used to distinguish one element from another, The scope of rights should not be limited by these terms.

It should be understood that terms such as “comprise” or “have” do not preclude the possibility of addition or existence of one or more other features or numbers, steps, operations, components, parts, or combinations thereof.

The term “at least one” should be understood to include all possible combinations from one or more related items. For example, the meaning of "at least one of the first, second, and third items" means 2 of the first, second, and third items as well as each of the first, second, or third items. It means a combination of all items that can be presented from more than one.

Hereinafter, an embodiment of a failure diagnosis system for an industrial robot according to the present invention will be described in detail with reference to the accompanying drawings.

1 and 2 are schematic block diagrams of a failure diagnosis system for an industrial robot according to the present invention, FIG. 3 is a schematic block diagram for explaining a noise diagnosis mechanism in the failure diagnosis system for an industrial robot according to the present invention, FIG. 4 7 to 7 are schematic views for explaining that the noise diagnosis mechanism derives a reference noise value in the failure diagnosis system of an industrial robot according to the present invention, and FIG. 8 is an amplitude modulation diagnosis in the failure diagnosis system of an industrial robot according to the present invention. A schematic block diagram for explaining the mechanism, FIGS. 9 to 11 are schematic diagrams for explaining that the amplitude modulation diagnosis mechanism derives a reference amplitude modulation value in the failure diagnosis system of an industrial robot according to the present invention.

1 to 11, the failure diagnosis system 1 of the industrial robot according to the present invention is for diagnosing the failure of the RV (revolutionary vector) gearbox used in the industrial robot. In particular, the failure diagnosis system 1 of the industrial robot according to the present invention uses at least one of a noise value and an amplitude modulation value for a vibration signal of a crankshaft bearing detected by a vibration sensor installed in an RV gearbox. By determining whether the RV gearbox has a failure, it is possible to determine whether the industrial robot has a failure.

To this end, the failure diagnosis system 1 of the industrial robot according to the present invention largely includes an RV gearbox 2 , a sensor unit 3 , and a failure diagnosis unit 4 .

Industrial robots may perform manufacturing processes such as welding processes, transport processes, and painting processes for parts constituting ships, vehicles, construction machines, mobile phones, etc. (hereinafter referred to as 'objects'). The industrial robot may include an RV gearbox 2 , and a crankshaft bearing may be installed in the RV gearbox 2 . The failure diagnosis system 1 of the industrial robot according to the present invention can determine whether the industrial robot has a failure by using a vibration signal generated when the crankshaft bearing installed inside the RV gearbox 2 rotates. .

Hereinafter, the RV gearbox 2, the sensor unit 3 and the fault diagnosis unit 4 will be described in detail with reference to the accompanying drawings.

1 to 11 , a crankshaft bearing (not shown) of the industrial robot is installed in the RV gearbox 2 . The RV gearbox 2 is mainly used as a reducer of an industrial robot. The RV gearbox 2 is a device for transmitting a high load or obtaining various speed ratios. The RV gearbox 2 may be installed between parts for increasing the degree of freedom of the industrial robot. For example, the RV gearbox 2 may be installed in various positions, such as between the joints and joints of the arm made of a plurality of joints, between the frame constituting the body of the industrial robot and the turning part for changing the direction of the frame. . A plurality of RV gearboxes 2 may be installed at different positions of the industrial robot. Accordingly, the RV gearbox 2 plays an important role in the industrial robot. If the RV gearbox 2 fails, the industrial robot may stop working. The failure diagnosis system 1 of the industrial robot according to the present invention can minimize the downtime when the operation of the industrial robot is stopped by quickly and accurately diagnosing the failure of the RV gearbox 2 . As the degree of damage or damage to the crankshaft bearing increases, the magnitude of vibration transmitted through the RV gearbox 2 may increase.

The crankshaft bearing is composed of a main bearing for supporting the crankshaft and a pin bearing fitted between the large end of the connecting rod and the crankpin. A split type plain bearing is mainly used as the crankshaft bearing. The failure diagnosis system (1) of the industrial robot according to the present invention extracts a noise value from a vibration signal generated when the crankshaft bearing is worn and damaged or damaged, and if the noise value exceeds a reference noise value, it is determined as a failure, If the noise value is equal to or less than the reference noise value, it may be determined as normal. For example, when the crankshaft bearing is damaged, the noise value may exceed the reference noise value. The failure diagnosis system 1 of the industrial robot according to the present invention extracts an amplitude modulation value from the vibration signal and determines that the amplitude modulation value exceeds a reference amplitude modulation value as a failure, and the amplitude modulation value is the reference amplitude modulation value Below, it can be judged as normal. For example, when the crankshaft bearing is damaged, the amplitude modulation value may exceed the reference amplitude modulation value. The failure diagnosis system 1 of the industrial robot according to the present invention may determine whether the industrial robot has a failure by using at least one of a noise value and an amplitude modulation value of a vibration signal of a crankshaft bearing.

The sensor unit 3 is for detecting the vibration of the crankshaft bearing. To this end, the sensor unit 3 may be coupled to the RV gearbox 2 . For example, the sensor unit 3 may be an acceleration sensor. The acceleration sensor may process an output signal to measure a dynamic force such as acceleration, vibration, or impact of an object. A plurality of the sensor units 3 are coupled to the RV gearbox 2 to be spaced apart from each other, thereby more accurately detecting the vibration of the crankshaft bearing compared to a case in which only one is installed. The sensor unit 3 may be installed on a crankshaft on which the crankshaft bearing is installed to sense vibration of the crankshaft bearing. The sensor unit 3 may be connected to the failure diagnosis unit 4 by at least one of wired communication and wireless communication. Accordingly, the sensor unit 3 may provide the detected vibration signal of the crankshaft bearing to the failure diagnosis unit 4 .

The fault diagnosis unit 4 may be connected to the sensor unit 3 and receive a vibration signal sensed by the sensor unit 3 . The failure diagnosis unit 4 may extract a noise value and an amplitude modulation value from the provided vibration signal and determine whether the industrial robot has a failure by using at least one. To this end, the fault diagnosis unit 4 may include a noise diagnosis mechanism 41 and an amplitude modulation diagnosis mechanism 42 .

The noise diagnosis mechanism 41 is for determining whether the industrial robot has a failure by using the noise value of the vibration signal. The noise may include vibration, noise, etc. generated when the crankshaft bearing is damaged or damaged. The noise diagnosis mechanism 41 determines that the noise value of the vibration signal detected by the sensor unit 3 exceeds the reference noise value as a failure, and if the noise value of the vibration signal is less than or equal to the reference noise value, it is determined to be normal. can In order to derive the reference noise value, the noise diagnosis mechanism 41 includes a noise aligning member 411, a noise extracting member 412, a noise averaging member 413, a noise residual member 414, and a noise reference member 415. may further include.

는 상기 크랭크축 베어링이 비정상이면서 시계방향으로 회전할 경우에 발생하는 가속도값이고,

는 상기 크랭크축 베어링이 정상이면서 반시계방향으로 회전할 경우에 발생하는 가속도값이다. 도 4에서 가로축은 시간이고, 세로축은 가속도값이다.Referring to FIG. 4 , the noise aligning member 411 may align acceleration values for each rotational direction of the crankshaft bearing. For example, the noise aligning member 411 may align an acceleration signal generated when the crankshaft rotates in a clockwise or counterclockwise direction according to the rotational direction according to time. 4 in

is an acceleration value that occurs when the crankshaft bearing rotates clockwise while abnormal,

is an acceleration value generated when the crankshaft bearing rotates in a normal and counterclockwise direction. In FIG. 4 , the horizontal axis represents time, and the vertical axis represents acceleration values.

Referring to FIG. 5 , the noise extracting member 412 may extract an acceleration value (raw signal) for each rotational direction from the acceleration values for each rotational direction aligned by the noise aligning member 411 . Accordingly, the noise extracting member 412 may extract an acceleration value generated when the crankshaft rotates clockwise and an acceleration value generated when the crankshaft rotates counterclockwise, respectively. .

Referring to FIG. 5 , the noise averaging member 413 may derive an average value of the acceleration values for each rotation direction. For example, the noise averaging member 413 may extract an average value (deterministic signal) through time synchronous averaging (TSA) for each rotation direction. The average value (deterministic signal) means an average within a specific section among noise-removed components. In FIG. 5 , the horizontal axis represents time, and the vertical axis represents an average value.

Referring to FIG. 6 , the noise residual material 414 may derive a residual value. The noise residual member 414 subtracts the average value (Deterministic Signal) derived by the noise averaging member 413 from the acceleration value (Raw Signal) for each rotational direction extracted by the noise extracting member 412, and the residual value ( residual) can be derived. In FIG. 6 , the horizontal axis represents time, and the vertical axis represents a residual value.

는 특정 구간에서의 기준노이즈값으로 상수일 수 있다.

은 특정 구간에서의 회전수이다.

는 특정 구간에서

번째 회전의 가속도값(Raw Signal)이다.Referring to FIG. 7 , the noise reference member 415 may derive a reference noise value. The noise reference member 415 may derive the reference noise value by RMS (Root Mean Square) of the residual value derived by the noise residual material 414 . in Fig.

may be a constant as a reference noise value in a specific section.

is the number of revolutions in a specific section.

is in a specific section

It is the acceleration value (Raw Signal) of the second rotation.

The noise diagnosis mechanism 41 compares the reference noise value with the noise value of the vibration signal detected by the sensor unit 3, and when the detected noise value exceeds the reference noise value, the RV gearbox 2 ) is determined to be a failure, and if the detected noise value is less than or equal to the reference noise value, it may be determined that the RV gearbox 2 is normal. Accordingly, the failure diagnosis system 1 of the industrial robot according to the present invention can quickly and accurately determine whether the industrial robot has a failure.

The amplitude modulation diagnosis mechanism 42 is for determining whether the industrial robot has a failure by using the amplitude modulation value of the vibration signal. The amplitude modulation is the frequency per unit time that occurs when the crankshaft bearing is damaged or damaged. That is, it may include a frequency. When the amplitude modulation value of the vibration signal detected by the sensor unit 3 exceeds the reference amplitude modulation value, the amplitude modulation diagnosis mechanism 42 determines a failure, and the amplitude modulation value of the vibration signal is less than or equal to the reference amplitude modulation value. If so, it can be considered normal. In order to derive the reference amplitude modulation value, the amplitude modulation diagnosis mechanism 42 may further include an amplitude modulation adjustment member 421 , an amplitude modulation frequency analysis member 422 , and an amplitude modulation reference member 423 .

는 상기 크랭크축 베어링이 비정상이면서 시계방향으로 회전할 경우에 발생하는 가속도값이고,

는 상기 크랭크축 베어링이 정상이면서 반시계방향으로 회전할 경우에 발생하는 가속도값이다. 도 9에서 가로축은 시간이고, 세로축은 가속도값이다.Referring to FIG. 9 , the amplitude change aligning member 421 may align acceleration values for each rotational direction of the crankshaft bearing. For example, the amplitude change adjustment member 421 may align the acceleration signals generated when the crankshaft rotates in a clockwise or counterclockwise direction for each rotational direction according to time. The amplitude change alignment member 421 may be the same as the noise alignment member 411 . in Fig.

is an acceleration value that occurs when the crankshaft bearing rotates clockwise while abnormal,

is an acceleration value generated when the crankshaft bearing rotates in a normal and counterclockwise direction. In FIG. 9 , the horizontal axis represents time, and the vertical axis represents acceleration values.

는 1초에 기어가 맞물리는 회수로, 기어의 회전속도에 따라 달라질 수 있다.Referring to FIG. 10 , the amplitude modulation frequency analysis member 422 may analyze the frequency value for each rotation direction. The amplitude modulation frequency analysis member 422 may obtain acceleration data for each rotation direction from the amplitude modulation adjustment member 421 and perform frequency analysis on each acceleration data. The amplitude modulation frequency analysis member 422 may perform frequency analysis on the acceleration data by extracting a side-band around a gear mesh frequency. When the amplitude modulation occurs, the side-band value may increase. in Fig.

is the number of times a gear engages per second, which may vary depending on the rotational speed of the gear.

는 특정 구간에서의 기준진폭변조값으로 상수일 수 있다.

는 주파수이고,

는 주파수의 진폭이다.Referring to FIG. 11 , the amplitude modulation reference member 423 may derive a reference amplitude modulation value. The amplitude modulation reference member 423 may derive the reference amplitude modulation value by performing Root Variance Frequency (RVF) with the frequency value analyzed by the amplitude modulation frequency analysis member 422 . 11 in Fig.

may be a constant as a reference amplitude modulation value in a specific section.

is the frequency,

is the amplitude of the frequency.

The amplitude modulation diagnosis mechanism 42 compares the reference amplitude modulation value with the amplitude modulation value of the vibration signal sensed by the sensor unit 3, and when the detected amplitude modulation value exceeds the reference amplitude modulation value, the If it is determined that the RV gearbox 2 is defective and the detected amplitude modulation value is less than or equal to the reference amplitude modulation value, it may be determined that the RV gearbox 2 is normal. Accordingly, the failure diagnosis system 1 of the industrial robot according to the present invention can quickly and accurately determine whether the industrial robot has a failure.

12 is a failure sensitivity graph measured for each rotational direction at a rotation speed of 50 deg/sec of a crankshaft bearing by the failure diagnosis system of an industrial robot according to the present invention, and FIG. 13 is a failure diagnosis system of an industrial robot according to the present invention. It is a graph of failure sensitivity measured by rotation direction at the bearing rotation speed of 100 deg/sec.

,

) 및 비정상(

,

)을 나타내며, 세로축은 상기 가로축 변수에 대한 고장민감도를 나타낸다. 가장 상측에 위치한 그래프는 진동신호 기반의 노이즈값(

)에 대한 고장민감도이고, 그 아래 위치한 그래프는 모터신호 기반(

,

)의 고장민감도이며, 가장 하측에 위치한 그래프는 진동신호 기반의 진폭변조값(

)에 대한 고장민감도이다. 도 12에 나타난 바와 같이, 상기 크랭크축 베어링의 회전속도가 50 deg/sec일 경우, 상기 진동신호 기반의 노이즈값(

)에 대한 고장민감도, 상기 모터신호 기반(

,

)의 고장민감도, 및 상기 진동신호 기반의 진폭변조값(

)에 대한 고장민감도는 크기만 다를 뿐 유사한 패턴으로 나타난다. 즉, 상기 크랭크축 베어링이 정상이면서 시계방향 또는 반시계방향으로 회전하는 경우는 상기 크랭크축 베어링이 비정상이면서 시계방향 또는 반시계방향으로 회전하는 경우에 비해 고장민감도값이 낮다. 여기서, 상기 진동신호 기반의 노이즈값(

)에 대한 고장민감도 및 상기 모터신호 기반(

,

)의 고장민감도는 상기 진동신호 기반의 진폭변조값(

)에 대한 고장민감도에 비해 높은 고장민감도값을 나타낸다. 이에 따라, 본 발명에 따른 산업용 로봇의 고장 진단 시스템(1)은 상기 크랭크축 베어링의 회전속도가 50 deg/sec일 경우 상기 진동신호 기반의 노이즈값(

)에 대한 고장민감도를 측정함으로써, 상기 RV기어박스(2)에 대한 고장 유무를 정확하면서 신속하게 파악할 수 있다.Referring to FIG. 12 , in the graph, the horizontal axis is the normal (

,

) and abnormal (

,

), and the vertical axis represents the failure sensitivity to the abscissa variable. The graph located at the top is the noise value (

), and the graph located below it is based on the motor signal (

,

), and the graph located at the bottom is the amplitude modulation value (

) is the failure sensitivity to 12, when the rotation speed of the crankshaft bearing is 50 deg/sec, the noise value (

) for fault sensitivity, based on the motor signal (

,

) of the failure sensitivity, and the amplitude modulation value based on the vibration signal (

), the failure susceptibility is shown in a similar pattern, only different in size. That is, when the crankshaft bearing rotates clockwise or counterclockwise while normal, the failure sensitivity value is lower than when the crankshaft bearing rotates abnormally and clockwise or counterclockwise. Here, the noise value (

) based on fault sensitivity and the motor signal (

,

) is the amplitude modulation value (

), it shows a higher failure sensitivity value than the failure sensitivity. Accordingly, the failure diagnosis system (1) of the industrial robot according to the present invention is a noise value based on the vibration signal when the rotation speed of the crankshaft bearing is 50 deg/sec.

), it is possible to accurately and quickly grasp the presence or absence of a failure in the RV gearbox (2) by measuring the failure sensitivity.

,

) 및 비정상(

,

)을 나타내며, 세로축은 상기 가로축 변수에 대한 고장민감도를 나타낸다. 가장 상측에 위치한 그래프는 진동신호 기반의 노이즈값(

)에 대한 고장민감도이고, 그 아래 위치한 그래프는 모터신호 기반(

,

)의 고장민감도이며, 가장 하측에 위치한 그래프는 진동신호 기반의 진폭변조값(

)에 대한 고장민감도이다. 도 13에 나타난 바와 같이, 상기 크랭크축 베어링의 회전속도가 100 deg/sec일 경우, 상기 진동신호 기반의 노이즈값(

)에 대한 고장민감도와 상기 모터신호 기반(

,

)의 고장민감도는 크기만 다를 뿐 유사한 패턴으로 나타난다. 상기 크랭크축 베어링의 회전속도가 100 deg/sec일 경우, 상기 진동신호 기반의 노이즈값(

)에 대한 고장민감도와 상기 모터신호 기반(

,

)의 고장민감도는 상기 크랭크축 베어링의 정상 또는 비정상에 상관없이 계속 증가하는 패턴을 보인다. 이에 따라, 상기 크랭크축 베어링의 회전속도가 100 deg/sec일 경우에는 상기 진동신호 기반의 노이즈값(

)에 대한 고장민감도와 상기 모터신호 기반(

,

)의 고장민감도를 측정하여, 상기 RV기어박스(2)에 대한 고장 유무를 파악할 수 없다. 반면, 상기 진동신호 기반의 진폭변조값(

)에 대한 고장민감도는 상기 진동신호 기반의 노이즈값(

)에 대한 고장민감도와 상기 모터신호 기반(

,

)의 고장민감도 패턴과 다른 패턴으로 나타난다. 즉, 상기 크랭크축 베어링이 정상이면서 시계방향 또는 반시계방향으로 회전하는 경우는 상기 크랭크축 베어링이 비정상이면서 시계방향 또는 반시계방향으로 회전하는 경우에 비해 고장민감도값이 낮게 나타난다. 이에 따라, 본 발명에 따른 산업용 로봇의 고장 진단 시스템(1)은 상기 크랭크축 베어링의 회전속도가 100 deg/sec일 경우 상기 진동신호 기반의 진폭변조값(

)에 대한 고장민감도를 측정함으로써, 상기 RV기어박스(2)에 대한 고장 유무를 정확하면서 신속하게 파악할 수 있다.Referring to FIG. 13 , in the graph, the horizontal axis is the normal (

,

) and abnormal (

,

), and the vertical axis represents the failure sensitivity to the abscissa variable. The graph located at the top is the noise value (

), and the graph located below it is based on the motor signal (

,

), and the graph located at the bottom is the amplitude modulation value (

) is the failure sensitivity to 13, when the rotation speed of the crankshaft bearing is 100 deg/sec, the noise value (

) and the motor signal based on (

,

) shows a similar pattern with only the difference in size. When the rotation speed of the crankshaft bearing is 100 deg/sec, the noise value (

) and the motor signal based on (

,

) shows a pattern that continues to increase regardless of whether the crankshaft bearing is normal or abnormal. Accordingly, when the rotation speed of the crankshaft bearing is 100 deg/sec, the noise value (

) and the motor signal based on (

,

), it is not possible to determine the presence or absence of a failure in the RV gearbox (2) by measuring the failure sensitivity. On the other hand, the amplitude modulation value (

), the failure sensitivity to the noise value (

) and the motor signal based on (

,

), which is different from the failure sensitivity pattern. That is, when the crankshaft bearing rotates clockwise or counterclockwise while normal, the failure sensitivity value is lower than when the crankshaft bearing rotates abnormally and clockwise or counterclockwise. Accordingly, the failure diagnosis system 1 of the industrial robot according to the present invention provides an amplitude modulation value (

), it is possible to accurately and quickly grasp the presence or absence of a failure in the RV gearbox 2 by measuring the failure sensitivity.

)에 대한 고장민감도를 측정하고, 상기 크랭크축 베어링의 회전속도가 고속일 경우 상기 진동신호 기반의 진폭변조값(

)에 대한 고장민감도를 측정함으로써, 상기 RV기어박스(2)에 대한 고장 유무를 파악하여 상기 산업용 로봇에 대한 고장 유무를 신속, 정확하게 파악할 수 있다. 또한, 본 발명에 따른 산업용 로봇의 고장 진단 시스템(1)은 상기 진동신호 기반의 진폭변조값(

)에 대한 고장민감도를 측정함으로써, 상기 크랭크축 베어링의 회전속도에 상관없이 상기 크랭크축 베어링의 회전방향에 따른 고장 유무까지 파악할 수 있으므로 상기 산업용 로봇에 대한 보수 및 교체 작업 시간을 단축시킬 수 있다. 따라서, 본 발명에 따른 산업용 로봇의 고장 진단 시스템(1)은 대상물에 대한 산업용 로봇의 제조공정이 지연되는 것을 최소화할 수 있다.Comparing FIGS. 12 and 13 , the failure diagnosis system 1 of the industrial robot according to the present invention provides a noise value based on the vibration signal when the rotation speed of the crankshaft bearing is low.

), and when the rotation speed of the crankshaft bearing is high, the amplitude modulation value (

), by measuring the failure sensitivity for the RV gearbox (2), it is possible to quickly and accurately grasp the presence or absence of a failure for the industrial robot by determining the presence or absence of a failure. In addition, the failure diagnosis system (1) of the industrial robot according to the present invention is an amplitude modulation value (

) by measuring the failure sensitivity, it is possible to determine whether there is a failure according to the rotational direction of the crankshaft bearing regardless of the rotational speed of the crankshaft bearing, so that the maintenance and replacement work time for the industrial robot can be shortened. Therefore, the failure diagnosis system 1 of the industrial robot according to the present invention can minimize the delay in the manufacturing process of the industrial robot for the object.

Although not shown, the failure diagnosis system 1 of the industrial robot according to the present invention may include a control unit. The control unit controls the industrial robot, and may be installed to be connected to the failure diagnosis unit 4 . Accordingly, the failure diagnosis system 1 of the industrial robot according to the present invention may stop the operation of the industrial robot through the control unit when it is determined that the industrial robot is malfunctioning. Therefore, the failure diagnosis system 1 of the industrial robot according to the present invention rapidly stops the operation of the industrial robot when the industrial robot is in failure, thereby reducing the degree of damage or damage to the industrial robot, thereby reducing repair and replacement costs can reduce

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and it is common in the technical field to which the present invention pertains that various substitutions, modifications, and changes are possible without departing from the technical spirit of the present invention. It will be clear to those who have the knowledge of

1: Failure diagnosis system for industrial robots
2: RV gearbox 3: sensor unit
4: fault diagnosis unit 41: noise diagnosis mechanism
411: noise aligning member 412: noise extracting member
413: noise average member 414: noise residual presence
415: noise reference member 42: amplitude modulation diagnosis mechanism
421: amplitude modulation alignment member 422: amplitude modulation frequency analysis member
423: amplitude modulation reference member

Claims (6)

delete delete RV gearbox in which crankshaft bearings of industrial robots are installed;
a sensor unit coupled to the RV gearbox and configured to sense vibration of the crankshaft bearing; and
A fault diagnosis unit connected to the sensor unit and receiving a vibration signal detected by the sensor unit,
The failure diagnosis unit determines whether the industrial robot has a failure by using at least one of a noise value and an amplitude modulation value of the vibration signal detected by the sensor unit,
The fault diagnosis unit,
a noise diagnosis mechanism for judging whether the industrial robot has a failure by using the noise value of the vibration signal; and
and an amplitude modulation diagnosis mechanism for judging whether the industrial robot has a failure by using the amplitude modulation value of the vibration signal,
The noise diagnosis device is
a noise aligning member for aligning acceleration values for each rotational direction of the crankshaft bearing;
a noise extracting member for extracting an acceleration value for each rotational direction;
a noise averaging member for deriving an average value of the acceleration values for each rotational direction;
a noise residual member for deriving a residual value by subtracting the average value derived by the noise averaging member from the acceleration values for each rotational direction extracted by the noise extracting member; and
A failure diagnosis system for an industrial robot comprising a noise reference member for deriving a reference noise value by performing RMS on the residual value derived from the noise residual material. 4. The method of claim 3,
The noise diagnosis mechanism determines a failure if the noise value of the vibration signal detected by the sensor unit exceeds the reference noise value, and determines that it is normal if the noise value of the vibration signal is less than or equal to the reference noise value Robot's fault diagnosis system. RV gearbox in which crankshaft bearings of industrial robots are installed;
a sensor unit coupled to the RV gearbox and configured to sense vibration of the crankshaft bearing; and
A fault diagnosis unit connected to the sensor unit and receiving a vibration signal detected by the sensor unit,
The failure diagnosis unit determines whether the industrial robot has a failure by using at least one of a noise value and an amplitude modulation value of the vibration signal detected by the sensor unit,
The fault diagnosis unit,
a noise diagnosis mechanism for judging whether the industrial robot has a failure by using the noise value of the vibration signal; and
and an amplitude modulation diagnosis mechanism for judging whether the industrial robot has a failure by using the amplitude modulation value of the vibration signal,
The amplitude modulation diagnosis mechanism,
an amplitude change aligning member for aligning acceleration values for each rotational direction of the crankshaft bearing;
an amplitude modulation frequency analysis member for analyzing the frequency value for each rotation direction; and
A failure diagnosis system of an industrial robot comprising an amplitude modulation reference member for deriving a reference amplitude modulation value by performing RVF with the frequency value analyzed by the amplitude modulation frequency analysis member. 6. The method of claim 5,
The amplitude modulation diagnosis mechanism determines that the amplitude modulation value of the vibration signal detected by the sensor unit exceeds the reference amplitude modulation value as a failure, and if the amplitude modulation value of the vibration signal is less than or equal to the reference amplitude modulation value, it is determined as normal A failure diagnosis system for industrial robots, characterized in that.

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