KR20180033844A - Fault Diagnosis System of Industrial Robot - Google Patents

Abstract

The present invention relates to a fault diagnosis system of an industrial robot, comprising: an RV gear box installed with a crank shaft bearing of an industrial robot; a sensor portion coupled to the RV gear box and sensing vibration of the crank shaft bearing; and a fault diagnosis portion connected to the sensor portion and receiving a vibration signal sensed by the sensor portion, wherein the fault diagnosis portion uses at least one of a noise value and an amplitude modulation value of the vibration signal sensed by the sensor portion to determine a fault of the industrial robot.

Description

{Fault Diagnosis System of Industrial Robot}

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

Generally, a ship, a vehicle, a construction machine, a cellular phone, etc. (hereinafter, referred to as an 'object') are manufactured by assembling various components. For example, a process of manufacturing an object through a manufacturing process such as a welding process, a transportation process, and a coating process for a component constituting an object is performed. A plurality of industrial robots can be installed in the process line to perform the above-described manufacturing process.

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

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

First, the fault diagnosis system of the industrial robot according to the related art diagnoses an abnormality using a current signal, so that when an abnormal current signal is detected from one component, an abnormal current signal is generated in many parts connected to the fault. Accordingly, in the fault diagnosis system of the industrial robot according to the related art, not only a separate technique is required to identify the part in which the first abnormal current signal is generated, but also it takes a long time to diagnose the trouble and the cost increases.

Second, the fault diagnosis system of the industrial robot according to the prior art diagnoses an abnormality using the current signal, and thus there is a problem that the accuracy of the fault diagnosis is low.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is an object of the present invention to provide a fault diagnosis system for an industrial robot that can quickly and accurately diagnose a fault of an industrial robot.

In order to solve the above-described problems, the present invention can include the following configuration.

The fault diagnosis system for an industrial robot according to the present invention comprises: an RV gear box in which a crankshaft bearing of an industrial robot is installed; A sensor unit coupled to the RV gear box and sensing 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 fault diagnosis unit may determine whether the industrial robot is faulty using at least one of a noise value and an amplitude modulation value of the vibration signal sensed by the sensor unit.

In the fault diagnosis system for an industrial robot according to the present invention, the fault diagnosis unit may include a noise diagnosis mechanism for determining whether the industrial robot is faulty using the noise value of the vibration signal, And an amplitude modulation diagnostic device for determining whether the industrial robot is malfunctioning.

In the fault diagnosis system for an industrial robot according to the present invention, the noise diagnosis device may include a noise sorting member for sorting the acceleration value of the crankshaft bearing according to the rotational direction, a noise extracting member for extracting the acceleration value by the rotational direction, A noise residual member for subtracting an average value derived by the noise average member from an acceleration value for each rotation direction extracted by the noise extracting member to derive a residual value, And a noise reference member for subjecting the residual value derived by the member to an RMS to derive a reference noise value.

In the fault diagnosis system for an industrial robot according to the present invention, the noise diagnosis device may determine that the noise value of the vibration signal sensed by the sensor exceeds a predetermined reference noise value, If it is below the noise value, it can be judged as normal.

In the fault diagnosis system for an industrial robot according to the present invention, the amplitude modulation diagnostic apparatus may include an amplitude modulation aligning member for aligning an acceleration value of each crankshaft bearing according to a rotational direction, an amplitude modulation frequency analysis And an amplitude modulation reference member for deriving a reference amplitude modulation value by RVF at a frequency value analyzed by the amplitude modulation frequency analysis member.

In the fault diagnosis system for an industrial robot according to the present invention, the amplitude modulation diagnostic apparatus may determine that a failure occurs when the amplitude modulation value of the vibration signal detected by the sensor unit exceeds the reference amplitude modulation value, If the value is less than or equal to the reference amplitude modulation value, it can be judged as normal.

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

The present invention is implemented to diagnose a failure of an industrial robot using a sensor installed in an RV gear box, thereby making it possible to quickly and accurately diagnose the failure of the industrial robot and to minimize the delay in the manufacturing process.

1 and 2 are schematic block diagrams of a fault diagnosis system for an industrial robot according to the present invention
3 is a schematic block diagram for explaining a noise diagnostic apparatus in a fault diagnosis system for an industrial robot according to the present invention
4 to 7 are schematic views for explaining a reference noise value derived by the noise diagnostic apparatus in the fault diagnosis system for an industrial robot according to the present invention
8 is a schematic block diagram for explaining an amplitude modulation diagnostic apparatus in a fault diagnosis system for an industrial robot according to the present invention
FIGS. 9 to 11 are schematic views for explaining an amplitude modulation diagnostic apparatus deriving a reference amplitude modulation value in a fault diagnosis system for an industrial robot according to the present invention
FIG. 12 is a graph showing a failure sensitivity graph of a failure diagnosis system for an industrial robot according to the present invention, which is measured at a rotation speed of 50 deg / sec at a crankshaft bearing in each rotation direction
FIG. 13 is a graph showing a failure sensitivity graph of a failure diagnosis system for an industrial robot according to the present invention measured at a rotation speed of 100 deg / sec at a crankshaft bearing,

It should be noted that, in the specification of the present invention, the same reference numerals as in the drawings denote the same elements, but they are numbered as much as possible even if they are shown in different drawings.

Meanwhile, the meaning of the terms described in the present specification should be understood as follows.

The word " first, "" second," and the like, used to distinguish one element from another, are to be understood to include plural representations unless the context clearly dictates otherwise. The scope of the right should not be limited by these terms.

It should be understood that the terms "comprises" or "having" does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

It should be understood that the term "at least one" includes all possible combinations from one or more related items. For example, the meaning of "at least one of the first item, the second item and the third item" means not only the first item, the second item or the third item, but also the second item and the second item among the first item, Means any combination of items that can be presented from more than one.

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

FIG. 1 is a schematic block diagram of a fault diagnosis system for an industrial robot according to the present invention. FIG. 3 is a schematic block diagram for explaining a noise diagnosis apparatus in a fault diagnosis system for an industrial robot according to the present invention. FIG. 7 is a schematic view for explaining a reference noise value derived by the noise diagnostic apparatus in the fault diagnosis system for an industrial robot according to the present invention. FIG. 8 is a schematic diagram for explaining an amplitude modulation diagnosis Figs. 9 to 11 are schematic diagrams for explaining that the amplitude modulation diagnostic apparatus derives a reference amplitude modulation value in the fault diagnosis system for an industrial robot according to the present invention. Fig.

1 to 11, a fault diagnosis system 1 for an industrial robot according to the present invention is for diagnosing a failure of an RV (revolutionary vector) gearbox used in an industrial robot. In particular, the fault 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 sensed by a vibration sensor installed in an RV gear box By judging the failure of the RV gear box, it is possible to judge the failure of the industrial robot.

To this end, the fault diagnosis system (1) of the industrial robot according to the present invention mainly includes an RV gear box (2), a sensor unit (3) and a fault diagnosis unit (4).

Industrial robots can perform manufacturing processes such as a welding process, a transportation process, and a painting process for parts constituting a ship, a vehicle, a construction machine, a mobile phone, and the like (hereinafter referred to as "object"). The industrial robot includes an RV gear box 2, and the RV gear box 2 may be provided with a crankshaft bearing. The fault diagnosis system 1 of the industrial robot according to the present invention can determine the failure of the industrial robot using a vibration signal generated when the crankshaft bearing installed in the RV gear box 2 rotates .

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

1 to 11, the RV gear box 2 is provided with a crankshaft bearing (not shown) of the industrial robot. The RV gear box 2 is mainly used as a speed reducer of an industrial robot. The RV gear box 2 is a device for transmitting a high load or obtaining various speed ratios. The RV gear box 2 may be installed between parts and parts for increasing the degree of freedom of the industrial robot. For example, the RV gear box 2 may be installed at various positions, such as between the joints and joints of the arm composed 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 . The RV gear box 2 may be installed at a plurality of different positions of the industrial robot. Accordingly, the RV gear box 2 plays an important role in the industrial robot. If the RV gear box 2 fails, the industrial robot can be stopped. The failure diagnosis system 1 of the industrial robot according to the present invention can quickly and accurately diagnose the failure of the RV gear box 2 to minimize the downtime of the operation of the industrial robot. As the degree of damage or breakage of the crankshaft bearing increases, the magnitude of the vibration transmitted through the RV gear box 2 can be increased.

The crankshaft bearing is constituted by a main bearing for supporting a crankshaft and a pin bearing fitted between a connecting rod large end portion and a crank pin. As the crankshaft bearing, mainly a split type planar bearing is used. The fault 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 broken and judges that the crush shaft bearing fails if the noise value exceeds a reference noise value, If the noise value is less than the reference noise value, it can be determined as normal. For example, when the crankshaft bearing is damaged, the noise value may exceed the reference noise value. The fault diagnosis system (1) of the industrial robot according to the present invention extracts an amplitude modulation value from the vibration signal and judges that the amplitude modulation value is a failure when the amplitude modulation value exceeds a reference amplitude modulation value. When the amplitude modulation value is a reference amplitude modulation value It can be judged as normal. For example, if the crankshaft bearing is damaged, the amplitude modulation value may become larger than the reference amplitude modulation value. The fault diagnosis system 1 of the industrial robot according to the present invention can judge the failure of the industrial robot using at least one of the noise value and the amplitude modulation value of the vibration signal of the crankshaft bearing.

The sensor unit 3 senses the vibration of the crankshaft bearing. For this purpose, the sensor unit 3 may be coupled to the RV gear box 2. For example, the sensor unit 3 may be an acceleration sensor. The acceleration sensor may process the output signal to measure dynamic forces such as acceleration, vibration, shock, etc. of the object. Since the sensor unit 3 is coupled to the RV gear box 2 so as to be spaced apart from each other, the vibration of the crankshaft bearing can be detected more accurately than when only one sensor unit 3 is installed. The sensor unit 3 may be installed on a crankshaft on which the crankshaft bearing is installed to sense the vibration of the crankshaft bearing. The sensor unit 3 may be connected to the fault diagnosis unit 4 through at least one of a wired communication and a wireless communication. Accordingly, the sensor unit 3 can provide the vibration diagnostic unit 4 with a vibration signal of the sensed crankshaft bearing.

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

The noise diagnostic device 41 is for judging the failure of the industrial robot using the noise value of the vibration signal. The noise may include vibration and noise generated when the crankshaft bearing is damaged or broken. When the noise value of the vibration signal sensed by the sensor unit 3 exceeds the reference noise value, the noise diagnosis mechanism 41 determines that the noise is malfunctioning. If the noise value of the vibration signal is lower than the reference noise value, . In order to derive the reference noise value, the noise diagnosis device 41 includes a noise sorting member 411, a noise extracting member 412, a noise average member 413, a noise remaining member 414 and a noise reference member 415, As shown in FIG.

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 the acceleration value of the crankshaft bearing according to the rotational direction. For example, the noise aligning member 411 may align the acceleration signal generated when the crankshaft rotates clockwise or counterclockwise according to the rotational direction according to time. 4,

Is an acceleration value generated when the crankshaft bearing rotates in a clockwise direction with an abnormality,

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 value.

5, the noise extracting member 412 may extract an acceleration value (Raw Signal) for each rotation direction from an acceleration value for each rotation direction aligned by the noise aligning member 411. FIG. Accordingly, the noise extracting member 412 can extract the acceleration value generated when the crankshaft rotates in the clockwise direction, and the acceleration value generated when the crankshaft rotates in the counterclockwise direction .

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

Referring to FIG. 6, the noise residual member 414 may derive a residual value. The noise residual member 414 subtracts the average value derived from the noise average member 413 from the acceleration value Raw signal extracted by the noise extracting member 412 by the rotation direction to obtain 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 performing a root mean square (RMS) on the residual value derived from the noise residual member 414. [ 7

May be a constant as a reference noise value in a certain section.

Is the number of revolutions in a specific section.

In a particular section

Is the acceleration value (Raw Signal) of the second rotation.

The noise diagnostic device 41 compares the reference noise value with the noise value of the vibration signal sensed by the sensor unit 3, and when the sensed noise value exceeds the reference noise value, the RV gear box 2 Is judged to be faulty, and if the sensed noise value is less than the reference noise value, it can be determined that the RV gear box 2 is normal. Accordingly, the fault diagnosis system 1 of the industrial robot according to the present invention can promptly and accurately determine whether the industrial robot is faulty.

The amplitude modulation diagnostic device 42 is for judging the failure of the industrial robot using the amplitude modulation value of the vibration signal. The amplitude modulation is a frequency per unit time that occurs when the crankshaft bearing is damaged or broken. That is, it may include a frequency. When the amplitude modulation value of the vibration signal sensed by the sensor unit 3 exceeds the reference amplitude modulation value, the amplitude modulation diagnostic device 42 determines that the amplitude modulation value is below the reference amplitude modulation value It can be judged as normal. The amplitude modulation diagnostic device 42 may further include an amplitude modulation alignment member 421, an amplitude modulation frequency analysis member 422, and an amplitude modulation reference member 423 to derive the reference amplitude modulation value.

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 modulation aligning member 421 may align the acceleration value of the crankshaft bearing according to the rotational direction. For example, the amplitude modulation aligning member 421 may align the acceleration signal generated when the crankshaft rotates clockwise or counterclockwise according to the rotational direction according to time. The amplitude modulation aligning member 421 may be the same as the noise aligning member 411. 9

Is an acceleration value generated when the crankshaft bearing rotates in a clockwise direction with an abnormality,

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 value.

는 1초에 기어가 맞물리는 회수로, 기어의 회전속도에 따라 달라질 수 있다.Referring to FIG. 10, the amplitude modulation frequency analyzing member 422 may analyze the frequency value for each rotation direction. The amplitude modulation frequency analyzing member 422 may acquire acceleration data for each rotation direction from the amplitude modulation aligning member 421 and perform frequency analysis on each acceleration data. The amplitude modulation frequency analysis member 422 can perform frequency analysis on the acceleration data by extracting a side-band around the Gear Mesh Frequency. When the amplitude modulation occurs, the side-band value can be increased. 10

Is the number of times the gears are engaged in one second, and may vary depending on the rotational speed of the gears.

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 can derive the reference amplitude modulation value by performing Root Variance Frequency (RVF) on the frequency value analyzed by the amplitude modulation frequency analysis member 422. 11

May be a constant as a reference amplitude modulation value in a certain interval.

Is a frequency,

Is the amplitude of the frequency.

The amplitude modulation diagnostic unit 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 sensed amplitude modulation value exceeds the reference amplitude modulation value, It can be determined that the RV gear box 2 is normal if the detected amplitude modulation value is less than the reference amplitude modulation value. Accordingly, the fault diagnosis system 1 of the industrial robot according to the present invention can promptly and accurately determine whether the industrial robot is faulty.

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

,

) 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.12, in the graph, the abscissa indicates the normal (the direction in which the crankshaft bearing rotates)

,

) And abnormal (

,

), And the vertical axis represents the fault sensitivity for the horizontal axis variable. The top graph shows the noise value based on the vibration signal (

), And the graph located beneath it is the motor signal based (

,

), And the graph at the bottom of the graph shows the amplitude modulation value based on the vibration signal

). ≪ / RTI > As shown in FIG. 12, when the rotational speed of the crankshaft bearing is 50 deg / sec, the noise value based on the vibration signal

, Fault sensitivity to the motor signal based (

,

), And the amplitude modulation value based on the vibration signal (

) Has a similar pattern with only a different magnitude of the fault sensitivity. That is, when the crankshaft bearing rotates clockwise or counterclockwise in a normal state, the failure sensitivity value is lower than when the crankshaft bearing rotates in an unsteady clockwise or counterclockwise direction. Here, the noise value based on the vibration signal

) And the motor signal based (< RTI ID = 0.0 >

,

) Is the amplitude modulation value based on the vibration signal (

) With a higher failure sensitivity value than the failure sensitivity to the other. Accordingly, in the fault diagnosis system 1 of the industrial robot according to the present invention, when the rotational speed of the crankshaft bearing is 50 deg / sec, the noise value based on the vibration signal

), It is possible to accurately and quickly grasp the failure of the RV gear box (2).

,

) 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.13, in the graph, the abscissa indicates the normal (in the direction of rotation of the crankshaft bearing)

,

) And abnormal (

,

), And the vertical axis represents the fault sensitivity for the horizontal axis variable. The top graph shows the noise value based on the vibration signal (

), And the graph located beneath it is the motor signal based (

,

), And the graph at the bottom of the graph shows the amplitude modulation value based on the vibration signal

). ≪ / RTI > As shown in FIG. 13, when the rotational speed of the crankshaft bearing is 100 deg / sec, the noise value based on the vibration signal

) And the motor signal based (< RTI ID = 0.0 >

,

) Has a similar pattern with only a different magnitude of failure sensitivity. When the rotational speed of the crankshaft bearing is 100 deg / sec, the noise value based on the vibration signal

) And the motor signal based (< RTI ID = 0.0 >

,

) Exhibits a continuously increasing pattern regardless of the normal or abnormal state of the crankshaft bearing. Accordingly, when the rotational speed of the crankshaft bearing is 100 deg / sec, the noise value based on the vibration signal

) And the motor signal based (< RTI ID = 0.0 >

,

The failure sensitivity of the RV gear box 2 can not be determined. On the other hand, the amplitude modulation value based on the vibration signal

) Is the noise value based on the vibration signal (

) And the motor signal based (< RTI ID = 0.0 >

,

) Failure pattern. That is, when the crankshaft bearing rotates clockwise or counterclockwise in a normal state, the failure sensitivity value is lower than when the crankshaft bearing rotates in an unsteady clockwise or counterclockwise direction. Accordingly, in the fault diagnosis system 1 of the industrial robot according to the present invention, when the rotation speed of the crankshaft bearing is 100 deg / sec, the amplitude modulation value

), It is possible to accurately and quickly grasp the failure of the RV gear box (2).

)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.12 and 13, the fault diagnosis system 1 of the industrial robot according to the present invention calculates the noise value based on the vibration signal when the rotation speed of the crankshaft bearing is low

), And when the rotational speed of the crankshaft bearing is high, the amplitude modulation value based on the vibration signal (

), It is possible to grasp the failure of the RV gear box 2 and quickly and accurately grasp the failure of the industrial robot. In addition, the fault diagnosis system 1 of the industrial robot according to the present invention calculates the amplitude modulation value

It is possible to grasp the failure according to the rotational direction of the crankshaft bearing irrespective of the rotational speed of the crankshaft bearing, thereby shortening the time required for repairing and replacing the industrial robot. Therefore, the fault 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 fault 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 fault diagnosis unit (4). Accordingly, the fault diagnosis system 1 of the industrial robot according to the present invention can stop the operation of the industrial robot through the control unit when it is determined that the industrial robot is defective. Therefore, the fault diagnosis system 1 of the industrial robot according to the present invention can quickly stop the operation of the industrial robot when the industrial robot is broken, thereby reducing the damage or damage to the industrial robot, .

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Will be clear to those who have knowledge of.

1: Fault diagnosis system of industrial robot
2: RV gear box 3: sensor part
4: fault diagnosis section 41: noise diagnosis apparatus
411: Noise alignment member 412: Noise extraction member
413: noise average member 414: noise residual member
415: noise reference member 42: amplitude modulation diagnostic instrument
421: Amplitude modulation alignment member 422: Amplitude modulation frequency analysis member
423: Amplitude modulation reference member

Claims (6)

An RV gear box in which the crankshaft bearing of the industrial robot is installed;
A sensor unit coupled to the RV gear box and sensing vibration of the crankshaft bearing; And
And a fault diagnosis unit connected to the sensor unit and receiving the vibration signal sensed by the sensor unit,
Wherein the fault diagnosis unit determines whether the industrial robot is faulty using at least one of a noise value and an amplitude modulation value of the vibration signal sensed by the sensor unit. The method according to claim 1,
The fault diagnosis unit,
A noise diagnostic device for determining whether the industrial robot is faulty using the noise value of the vibration signal; And
And an amplitude modulation diagnostic device for determining whether the industrial robot is faulty using the amplitude modulation value of the vibration signal. 3. The method of claim 2,
The noise diagnostic apparatus includes:
A noise aligning member for aligning the acceleration value of the crankshaft bearing in the rotational direction;
A noise extraction member for extracting the acceleration value by the rotation direction;
A noise average member for deriving an average value of the acceleration values by the rotation direction;
A noise residual member for subtracting an average value derived by the noise average member from an acceleration value for each rotation direction extracted by the noise extracting member to derive a residual value; And
And a noise reference member for performing RMS on the residual value derived by the noise residual member to derive a reference noise value. The method of claim 3,
Wherein the noise diagnostic apparatus determines that the noise value of the vibration signal sensed by the sensor unit is a failure when the noise value exceeds the reference noise value and determines that the noise value is normal when the noise value of the vibration signal is less than the reference noise value Fault diagnosis system of robot. 3. The method of claim 2,
Wherein the amplitude modulation diagnostic apparatus comprises:
An amplitude modulation aligning member for aligning the acceleration value of the crankshaft bearing according to the rotational direction;
An amplitude modulation frequency analysis unit for analyzing the frequency value of each rotation direction; And
And an amplitude modulation reference member for deriving a reference amplitude modulation value by RVF at a frequency value analyzed by the amplitude modulation frequency analysis member. 6. The method of claim 5,
Wherein the amplitude modulation diagnostic apparatus determines that the amplitude modulation value of the vibration signal sensed by the sensor unit exceeds a predetermined amplitude modulation value and determines that the amplitude modulation value is normal if the amplitude modulation value of the vibration signal is less than the reference amplitude modulation value Wherein the fault diagnosis system comprises:

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