JP3221194B2 - Operational waveform diagnostic device for industrial robots - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operation waveform diagnosing apparatus for an industrial robot, and more particularly to an apparatus for automatically diagnosing the waveform of operation data and displaying the result.

[0002]

2. Description of the Related Art At present, industrial robots (hereinafter simply referred to as "robots") are being actively introduced in various production plants including automobile factories. Such robot systems are generally used as shown in FIG. A robot main body 1 (for example, a multi-axis robot having a plurality of drive axes provided with servo motors), a controller 2 for controlling the same, and an amplifier 3 (for example, a digital servo amplifier) for amplifying signals and the like. in this case,
The robot body 1 is connected to the amplifier 3 via a D / A converter 4 and an A / D converter 5. After the speed command or the position command from the controller 2 is amplified by the amplifier 3, it is sent to each axis of the robot body 1 via the D / A converter 4. Thereby, the robot body 1 performs a predetermined operation, and at this time, operation data of each axis (for example, speed feedback data from the encoder, current data, etc.).
Are input to the amplifier 3 via the A / D converter 5 and then sent to the controller 2.

Conventionally, in some systems, the operation data is further stored in a memory in the controller 2 and its signal waveform is displayed (see FIG. 14). In this way, the quality of the waveform during the operation of each robot body 1 is determined to provide assistance for investigating the cause of a malfunction, checking the contents of aging, tuning, and the like. FIG. 14 shows a display example of a signal waveform, and FIG. 14A shows waveforms of a speed command (dotted line) and a speed feedback signal (solid line) with respect to time.
FIG. 7B shows a waveform of the current value with respect to time.

[0004]

However, in such a conventional operation waveform display method, data when each axis of the robot main body 1 operates is stored in a memory in the controller 2 via the amplifier 3. The data is rewritten and the previous data does not remain when the next operation is performed. Therefore, in order to keep the previous operation data, it is necessary to perform data communication and store the data in an external data file, or to print and leave it on paper.

[0005] When evaluating the waveform of the operation data, whether it is a method of reading out from a data file and displaying it on a screen or a method of printing it on paper, a person having specialized knowledge is required to evaluate the past data. It was necessary to prepare data and compare it with the waveform on the screen or on paper to determine the quality of the waveform, and to determine which part of the waveform was the problem.

SUMMARY OF THE INVENTION The present invention has been made in view of such problems of the prior art, and has an operation waveform diagnosis apparatus for an industrial robot capable of automatically diagnosing the operation data waveform of the robot and displaying the result. The purpose is to provide.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a robot main body for performing a predetermined operation, a controller for controlling the robot main body, and a speed waveform, a current waveform, Or position waveform
Storage means for storing a history of operating data of the robot body consisting shift one, and the operation waveform feature extracting means for extracting a feature value of the waveform of the operation data is compared with a reference waveform, the features and the reference waveform Standard data creating means for creating standard data modeled based on the amount, standard data adjusting means for adjusting the standard data in accordance with the operation data, and the adjusted standard data and the operation data It is characterized by having a waveform diagnosis means for performing a waveform diagnosis of the operation data while looking up a previously set waveform diagnosis comment table for comparison, and a display means for displaying a result of the waveform diagnosis.

[0008]

According to the present invention constructed as described above, the velocity wave
The operation data of the robot body composed of any one of the shape, the current waveform, and the position waveform is sequentially taken into the storage means by communication with the controller, and is stored in the history file of the operation data. The operation waveform feature extraction means reads out a required number of pieces of operation data from the storage means and compares them with a reference waveform to extract a feature amount of the waveform of each operation data. The standard data creating means creates standard data modeled based on the reference waveform and the extracted feature amount. The standard data adjusting means adjusts the standard data according to the operation data in order to adjust the created standard data to the scale of the operation data for performing waveform diagnosis. The waveform diagnosis means compares the adjusted standard data with the operation data, and performs a waveform diagnosis of the operation data while looking up a preset waveform diagnosis comment table. The result of the waveform diagnosis is displayed on the display means.

[0009]

An embodiment of the present invention will be described below with reference to the drawings. 1 is a schematic configuration diagram of the present embodiment, FIG. 2 is a configuration diagram of a main part of FIG. 1, FIG. 3 is a diagram showing an example of a comment table, FIG. 4 is an operation flowchart of the embodiment, and FIGS. 8 to 10 are waveform diagrams for explaining FIGS. 5 to 7 respectively, FIG. 11 is a diagram for explaining a method of adjusting standard data, and FIG. It is a figure which shows the example of a display by. Note that parts common to those in FIG. 13 are denoted by the same reference numerals.

[0010] The robot operation waveform diagnostic apparatus shown in FIG.
And a controller 2 for controlling this, and an amplifier 3 for amplifying signals and the like. Here, as the robot body 1, for example, a multi-axis robot having a plurality of drive shafts provided with servo motors is used. As the amplifier 3, for example, a digital servo amplifier is used. Robot body 1
Is an amplifier 3 via a D / A converter 4 and an A / D converter 5
Is connected to As a result, after the speed command or the position command from the controller 2 is amplified by the amplifier 3,
Sent to each axis of the robot body 1 via the / A converter 4,
As a result, the robot body 1 performs a predetermined operation, and the operation data of each axis (for example, speed feedback data from the encoder, current data, etc.) at this time is A / D.
After being input to the amplifier 3 via the converter 5, it is sent to the controller 2. Note that the D / A converter 4 and the A / D converter 5 may be configured integrally with the amplifier 3.

Further, in this embodiment, the controller 2
For example, the data terminal device of the workstation 10 is connected via the data communication interface 7 of the RS-232C. As a result, the operation data of the robot body 1 input to the controller 2 is transferred to the workstation 10 by data communication. Note that a personal computer or the like may be used instead of the workstation 10 as the data terminal device.

As shown in FIG. 2, the workstation 10 comprises a main body 11, a keyboard 12, and a display device 13 as display means.
Reference numeral 1 denotes a communication processing unit 15 for performing data communication between the input / output interface 14 and the controller 2, a data file 16 for storing various data, and a simulation unit for performing simulation-related processing to create simulation data. A waveform feature extraction unit 18 as an operation waveform feature extraction unit for extracting a feature amount of a waveform of the acquired operation data by comparing with a reference waveform (specifically, simulation data or standard data as described later); A standard data creating unit 19 as standard data creating means for creating modeled standard data by adding the feature amount to a reference waveform; and standard data adjusting means for adjusting the standard data to the scale of operation data to be subjected to waveform diagnosis. Standard data adjustment unit 20, and the adjusted standard data and the operation data Compared to and a preset waveform diagnostic comment table 21a to look-up while the waveform diagnosing section 21 serving as a waveform diagnosis means for performing a waveform diagnosis of the operation data. The data file 16 includes a waveform data history data file 16a as storage means for storing the operation data taken from the controller 2, and a failure history data file 16b for storing the history of operation data at the time of failure. The waveform diagnosis comment table 21a is a list of comments on operation data added in the waveform diagnosis (see FIG. 3), and is stored in, for example, a memory in the waveform diagnosis unit 21. This comment table is, for example, as shown in FIG.
As shown in (1), there are comments on the speed waveform (qualitative or causal), comments on the current waveform (qualitative or causal), etc. Set to.

The apparatus constructed as above operates as follows in accordance with the flowcharts of FIGS. This flowchart is executed for each program of each axis of each robot.

First, when the operator performs modeling for simulation in the simulation section 17 in the workstation 10 (S1), the simulation section 17 executes the simulation (S1).
2) It is determined whether the initial model is appropriate by comparing it with the operation data of the robot body 1 (hereinafter, referred to as an actual machine) actually operated (S3). If the result of this determination is not proper, the process returns to step 1 and returns to steps 1 to 3
Is repeated.

If the initial model is appropriate, the simulation unit 17 calculates the values of various parameters of a simulation block diagram for realizing the initial model, and performs operation data (eg, speed feedback signal) for waveform diagnosis. , Current value, position feedback signal, etc.)
Create simulation data corresponding to (S
4).

Then, the communication processing unit 15 in the workstation 10 transmits various data (for example, a speed command output from the controller 2 to the real machine 1) during the operation of the real machine 1.
The speed feedback signal and the position feedback signal from the encoder attached to each axis of the actual machine 1, the current value flowing through the servomotor of each axis, etc.) are taken in by data communication with the controller 2, and the data for the waveform data history are taken. It is stored in the file 16a (S5). then,
It is determined whether or not the necessary number of waveform data of the actual device 1 has been taken in to create the standard data (S6). If the required number has not been reached as a result of this determination, the process returns to step 5 and returns to steps 5 and 6 Is repeated.

If the required number of waveform data of the actual machine 1 has been fetched, the waveform feature extraction unit 18 in the workstation 10 determines whether or not the mode is the initial standard data creation mode (7), and as a result of this determination, If the mode is the initial standard data creation mode, the process proceeds to step 8 to create the standard data using the simulation data as the reference waveform. On the other hand, if the mode is not the initial standard data creation mode, that is, the standard data has already been created. If yes, step 1
The process proceeds to 0, and new standard data is created using the standard data as a reference waveform, that is, the standard data is updated.

That is, in the case of the initial standard data creation mode, the waveform feature extraction unit 18 compares the acquired data of the actual machine 1 with the simulation data as the reference waveform and performs each operation. The feature amount of the data waveform is extracted (S8). The contents of this subroutine are shown in FIG.
7 to FIG.

FIG. 5 is a flowchart when the operation data is a velocity waveform. In this case, the waveform feature extraction unit 18
First, as shown in FIG. 8A, the speed command (dotted line)
The delay amount of the speed feedback signal (solid line) with respect to, for example, the amount of the cross start point a, the target speed arrival point b, the cross end point c, etc. is extracted (S15), and then, as shown in FIG. Features of the feedback waveform at the time of speed, for example, peak-to-peak magnitude (average value and maximum value) d, vibration center position e, and vibration period (average value) f are extracted (S16).

FIG. 6 is a flowchart when the operation waveform is a current waveform. In this case, first, as shown in FIG. 9A, the waveform feature extraction unit 18 approximates the rising waveform g by a quadratic expression using the least squares method, and extracts each coefficient. S17), in order, as shown in FIG. 9B, take out the maximum current value h and the required time i up to that time (S18), take out the current value j at constant speed (S19), and take the current during deceleration. The value k is taken out (S20), and the current value m in the steady state is taken out (S21).

FIG. 7 is a flowchart when the operation data is a position waveform. In this case, as shown in FIG. 10, the waveform feature extraction unit 18 first approximates the waveform p at the time of rising (at the time of acceleration) by a quadratic expression using the least squares method and extracts each coefficient (S22). ), Then also a minimum of 2
Using the multiplication method, the waveform q at the time of deceleration is approximated by a quadratic expression to extract each coefficient (S23).

When the characteristic amount of the waveform of each operation data of the actual machine 1 is extracted in this way, the standard data creating unit 19 in the workstation 10 adds the characteristic amount to the simulation data and converts the modeled standard data into the standard data. It is created (S9). Specifically, the standard data is created by changing the parameters of the block diagram for simulation and reproducing the waveform of the operation data of the actual machine 1.
For example, when the delay of the rise of the speed feedback signal is large, the value of the parameter is changed to increase the static friction resistance.

On the other hand, when the mode is not the initial standard data creation mode, the standard data has already been created.
The aging of the characteristics of the actual machine 1 becomes a problem. Therefore, in this case, the waveform feature extraction unit 18 compares the acquired data of the actual machine 1 with the standard data as the reference waveform, using the standard data that has already been created as the reference waveform, and compares the aging of each operation data. Is extracted (S10), and the standard data is updated by adding the extracted aging to the standard data (S11). The extraction of the secular change is specifically performed by extracting the characteristic amount of the waveform of each of the fetched motion data as in step 8, so that the contents of steps 10 and 11 are based on the simulation data as the reference waveform. Steps 8 and 9 are the same except for the difference between the use and the use of the standard data.

When the standard data is newly created or updated, the standard data adjusting unit 20 in the workstation 10 performs, based on, for example, a speed command among the operation data of the actual machine 1 for performing a waveform diagnosis. The various waveforms of the standard data are adjusted to match the scale of the speed command waveform as a reference (S12). Specifically, for example, first, the difference r in the time axis direction with reference to the velocity waveform
Then, the standard data is multiplied by a constant based on the difference r, then the maximum value difference s is calculated, and the standard data is multiplied by a constant based on the difference s (see FIG. 11). Then, the current waveform and the like are also adjusted using the values of the differences r and s. FIG.
Shows standard data before adjustment (dotted line) and standard data after adjustment (dotted line).

When the standard data is adjusted in accordance with the actual data in this way, the waveform diagnostic section 21 in the workstation 10 compares the operation data of the actual machine 1 with the standard data scale-adjusted accordingly. Then, while looking up the comment table 21a (see FIG. 3), a waveform diagnosis of the operation data of the actual machine 1 is performed, and a comment on the data such as whether the waveform state is good or bad, and what part is causing the problem and what is the problem is provided. Attach (S13). The comparison is performed by comparing the various feature amounts extracted in step 8 or step 10 with standard data.

When the waveform diagnosis is completed, the operation data (solid line) of the actual machine 1 and the adjusted standard data (dashed line) are commented through the display interface in the input / output interface 14, as shown in FIG. Is displayed on the screen of the display device 13 (S14).

Therefore, in this embodiment, since the workstation 10 is connected to the controller 2, the operation data of each axis of the robot body 1 can be stored in the data file 16a in the workstation 10 by data communication. it can. In addition, since standard data is created from these data and this standard data is compared with actual data automatically, it is possible to automatically diagnose the waveform of actual operation data and display the result As a result, the knowledge of the waveform diagnosis expert is shared, and the efficiency of the operation of diagnosing the operation waveform of the robot is dramatically improved.

[0028]

As described above, according to the present invention, the waveform of the actual operation data of the robot body can be automatically diagnosed and the result can be displayed. Is dramatically improved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of the present embodiment.

FIG. 2 is a configuration diagram of a main part system of FIG. 1;

FIG. 3 shows an example of a comment table.

FIG. 4 is an operation flowchart of the embodiment.

FIG. 5 is a flowchart showing the contents of a subroutine of FIG. 4;

FIG. 6 is a flowchart showing the contents of a subroutine in FIG. 4;

FIG. 7 is a flowchart showing the contents of a subroutine of FIG. 4;

8 is a waveform chart for explaining FIG. 5;

FIG. 9 is a waveform chart for explaining FIG. 6;

FIG. 10 is a waveform chart for explaining FIG. 7;

FIG. 11 is a diagram for explaining a method of adjusting standard data.

FIG. 12 is a diagram showing a display example according to the embodiment.

FIG. 13 is a schematic configuration diagram showing an example of a conventional robot system.

FIG. 14 is a diagram showing a display example of operation data.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Robot main body 2 ... Controller 3 ... Amplifier 10 ... Workstation 13 ... Display device (display means) 16a ... Waveform data history data file (storage means) 18 ... Waveform feature extraction part (operation waveform feature extraction means) 19 ... Standard Data creation unit (standard data creation unit) 20: Standard data adjustment unit (standard data adjustment unit) 21: Waveform diagnosis unit (waveform diagnosis unit)

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G05B 23/02 G05B 23/02 301 B25J 19/06 G05B 19/19

Claims (1)

(57) [Claims] 1. A robot main body for performing a predetermined operation, a controller for controlling the robot main body, and communicating with the controller to generate a velocity waveform, a current waveform, or the like.
Other storage means for storing a history of operating data of the robot body or consisting one position waveform, and the operation waveform feature extracting means is compared with a reference waveform to extract a feature amount of the waveform of the operation data, the Standard data creating means for creating standard data modeled based on a reference waveform and the feature quantity; standard data adjusting means for adjusting the standard data in accordance with the operation data; and the adjusted standard data. Waveform diagnosis means for performing waveform diagnosis of the operation data while looking up a previously set waveform diagnosis comment table by comparing with the operation data, and display means for displaying a result of the waveform diagnosis. A waveform diagnostic device for an industrial robot, comprising: