JP7278803B2 - Information processing method, information processing device, robot system, robot system control method, article manufacturing method using robot system, program, and recording medium - Google Patents

Description

The present invention relates to a robot control device and control method having joints.

2. Description of the Related Art Conventionally, various robot devices have been used in factories and the like, and recently, robot devices equipped with robot arms having joints for performing more complicated motions have become widely used.

For example, a multi-axis, multi-joint robot arm has a high degree of freedom of movement, so there is a risk that the robot arm will come into contact with other objects such as workpieces and tools during work, and the robot arm will be damaged. be. In particular, reduction gears provided in joints are known to be delicate parts and easily damaged.

If the speed reducer is damaged, the motion accuracy of the robot arm is deteriorated, so that the desired motion becomes impossible and the robot stops abnormally. Therefore, in recent years, various anomaly detection techniques for reduction gears of robot arms have been proposed. One of them is a method focusing on the magnitude of vibration when a robot is caused to perform a predetermined motion.

For example, in Japanese Unexamined Patent Application Publication No. 2002-100001, the joint actuator is maintained at the speed at which the robot resonates most for a certain period of time, and the vibration of the arm generated at that time is detected. A technique has been proposed in which arm vibration is detected using a torque fluctuation value calculated from a motor torque value, and abnormality is determined by comparing the fluctuation width with a threshold value.

JP 2006-281421 A

However, it is known that the driving speed of the joint at which the robot resonates the most varies somewhat depending on the individual difference of the robot and the state of the joint. Therefore, when the method of Patent Document 1 is actually performed, it is necessary to perform driving at a constant speed a plurality of times while changing the speed little by little, and to search for the point where the resonance is the greatest among them, which takes time for inspection. There was a problem.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a robot diagnostic method and a robot diagnostic apparatus capable of diagnosing the state of a speed reducer of an articulated robot in a short time.

In order to solve the above-mentioned problems, the present invention provides an information processing method for acquiring information about a robot having joints equipped with reduction gears, wherein a predetermined joint is displayed on a display unit so that a predetermined joint can be selected from among the joints, An information processing method , comprising diagnosing whether or not a predetermined speed reducer of the selected predetermined joint has an abnormality , and displaying a history of the diagnosis result of the predetermined speed reducer on the display unit. It was adopted.

By using this configuration, it is possible to shorten the diagnosis time for the state of the speed reducer of the articulated robot .

Diagram showing a 6-axis robot system A diagram showing the joint structure of a 6-axis robot Diagram showing the internal configuration of the controller A diagram showing the UI screen for diagnosis Diagram showing configuration of diagnostic function A diagram showing how to generate inspection actions. Diagram representing diagnostic flow A diagram showing a data processing method for calculating the judgment value A

In this embodiment, the state (including the state of deterioration) of a speed reducer particularly using a strain wave gear mechanism is diagnosed through the resonance phenomenon that occurs in the joints of the robot device. The detection of the state of the transmission of the joint of the robot device through the resonance phenomenon of the joint is based on the following principle.

If the speed reducer is damaged due to the above-described cushioning or collision, an angle transmission error occurs due to tooth skipping or the biting of small pieces caused by the damage. This angle transmission error is, for example, the error between the input angle on the primary side of the speed reducer and the output angle obtained on the secondary side of the speed reducer via the gear ratio.

On the other hand, the joints of a robot using a speed reducer using strain wave gears have a resonance frequency f (Hz: natural frequency) as shown in the following equation (1).

Here, f is the resonance frequency (Hz: natural frequency) of the vibration system including the speed reducer, K is the spring constant of the speed reducer, and J is the load inertia (kgm2) of the load driven by the joint provided with the speed reducer. be. Among these, the spring constant K is a constant term and is unique to each type of speed reducer. Also, J corresponds to the moment of inertia applied to the target joint axis, and its magnitude varies depending on the size and posture of the robot arm and the weight of the object attached to the hand.

Also, the speed reducer is a rotary drive system, and the resonance frequency f (Hz: natural frequency) corresponds to the rotation speed R (rpm: rotation speed per minute) as in the following equation (2).

Therefore, when the rotation speed of the input side of the speed reducer reaches the rotation speed R that satisfies the equation (2), a resonance phenomenon occurs in the joint. That is, when the joint is driven, speed unevenness synchronizing with the resonance frequency f occurs in the vicinity of the driving rotation speed of equation (2).

There is a relationship between the angle transmission error of such a speed reducer and the magnitude of resonance. For example, an angular transmission error occurs when other teeth periodically bite into the teeth of a speed reducer gear that have been chipped due to a sudden overload such as a collision. When the vibration system matches the resonance frequency with an angular transmission error occurring, the arm resonates more than when it resonates in a normal state.

Also, even if the gears are not damaged, if the reduction gear (whole) is elliptically distorted, the web generator, which is one of the parts that make up the wave gear mechanism of the reduction gear, is periodically deformed. When the vibration system matches the resonance frequency with this deformation occurring, the arm resonates more strongly than when it resonates in a normal state.

As described above, it can be considered that the resonance phenomenon that occurs in the joints of the robot manifests itself in the form of vibration of the joints due to the angular transmission error of the speed reducer. Therefore, the amplitude of resonance generated in the joints (reducers of) of the robot arm is measured by, for example, an encoder, current sensor, or torque sensor, and this resonance amplitude is used as an index (reference) value corresponding to the angular transmission error, which is a predetermined reference. The speed reducer can be diagnosed by comparing the values. In particular, since the output shaft encoder can directly detect rotation unevenness on the output side of the speed reducer, it is preferable to use the output shaft encoder for this diagnosis. Therefore, although an example using an output shaft encoder is shown in this embodiment, detection is also possible using an input side encoder, a motor current value, a torque value, and an acceleration sensor.

Moreover, in order to clarify which joint's speed reducer is damaged in this diagnosis, it is desirable to stop all joints other than the target joint and operate only the target joint. Therefore, when diagnosing all joints, an inspection operation is performed for each joint.

The measurement and diagnosis of the joints of the robot device based on the above principle will be specifically described below with reference to the embodiments shown in FIGS. In this embodiment, an example of diagnosis using an output shaft encoder is shown.

1 to 3 show an example of the configuration of a robot system that can implement the present invention. FIG. 1 schematically shows the overall configuration of the robot system. FIG. 2 shows a cross-sectional structure near one joint of the robot system of FIG. 3 shows the configuration of the control device 200 of the robot system of FIG.

As shown in FIG. 1, the robot system includes a robot device 100 that assembles and manufactures a work W, a control device 200 that controls the robot device 100, and a teaching pendant 300 connected to the control device 200.

The robot arm 100 includes a base portion 101 (base) fixed to a workbench, a plurality of links 102 to 107 that transmit displacement and force, and a plurality of joints that connect the links 102 to 107 so that they can turn or rotate. 111-116. In this embodiment, the configurations of the joints 111 to 116 are basically the same. For this reason, in the following description, regarding the configuration common to the joints 111 to 116, the configuration of the joint 112 between the link 102 and the link 103 will be described as a representative, and the other joints 111, 113 to 116 will be specifically described. explanation is omitted. This embodiment can be implemented if at least one of the joints 111 to 116 of the robot arm 100 has a joint having the same configuration as the joint 112 .

By operating this robot system and executing the control method described below, it is possible to contribute to stable operation of the robot system and, in turn, to efficiently manufacture articles with this robot system.

As shown in FIG. 2, the joint 112 includes a servomotor (motor) 12 as a rotational drive source and a speed reducer 11 that reduces (speeds) the output of the servomotor 12 (transmission). It also has an input-side encoder 8 as an input-side angle sensor for detecting the rotation angle of the motor shaft 4 of the servomotor. The rotation angle (output side rotation angle) of the joint 112 on the output side of the speed reducer 11 is detected by an output side encoder 10 (rotary encoder) as an output side angle sensor. The input side encoder 8 and the output side encoder 10 have the same configuration as general rotary encoders, and are configured by optical or magnetic rotary encoder devices.

The servomotor 12 can be composed of, for example, an electromagnetic motor such as a brushless DC motor or an AC servomotor. The servomotor 1 may be provided with a brake unit for maintaining the posture of the robot arm 100 when the power is turned off, if necessary.

The speed reducer 11 includes a web generator 1 as an input section, a circular spline 3 as an output section, and a flexspline 2 arranged between the web generator 1 and the circular spline 3 . The web generator 1 is connected to the other end of the rotating shaft 4 of the servomotor 12 . Circular spline 3 is connected to link 103 . Flexspline 2 is connected to link 102 . That is, the connecting portion between the rotating shaft 4 of the servomotor 12 and the web generator 1 is the input side of the speed reducer 11 , and the connecting portion between the flexspline 2 and the link 103 is the output side of the speed reducer 11 . Then, the rotation shaft 4 of the servo motor 12 is decelerated to 1/N (reduced by the deceleration ratio N) via the decelerator 11, and the links 102 and 103 rotate relatively. The rotation angle on the output side of the speed reducer 11 at this time is the actual output angle, that is, the angle of the joint 112 .

An output-side encoder (output-side angle sensor) 10 is provided on the output side of the speed reducer 11 and detects the relative angle between the link 102 and the link 103 . Specifically, the output-side encoder 10 generates an output-side pulse signal as the joint 112 is driven (relative movement between the link 102 and the link 103 ), and outputs the output-side pulse signal to the control device 200 . A cross roller bearing 9 is provided between the link 102 and the link 103 , and the link 102 and the link 103 are rotatably connected via the cross roller bearing 9 .

FIG. 3 is an internal block diagram of the robot system centering on the controller 200. As shown in FIG. The control device 200 is composed of a portable or stationary computer. A communication bus 210 is provided inside, and a CPU 216 for various calculation processes, a RAM 217, and a ROM 218 for storing a control program 219 are connected by communication. The control program 219 stores not only a program for controlling the robot system as a whole, but also a program that the CPU reads and executes to enable execution of inspections described below. Also, the input side encoder 8, the output shaft encoder 10, the servo motor 12, the operation button 312 and the display section 311 of the teaching pendant 300 of the robot 100 are connected by communication via the I/F (211-215).

A medium for storing the control program 219 is not limited to the ROM 218, and may be a recording medium such as a hard disk, a semiconductor memory, an optical disk, or a magneto-optical disk.

A user inputs an instruction through the TP operation button 312 , and the program 205 is called up according to the instruction, and the servo motor 12 of the robot 100 is controlled through the servo control device 201 . At this time, the CPU 216 controls the servo control device 201 and also plays the role of a drive control section that drives and controls the motor.

Next, the configuration and flow for diagnosis will be described with reference to FIGS. 4 to 8. FIG.

FIG. 4 is a diagram showing a diagnosis mode UI for a user to set diagnosis when performing diagnosis. The UI is displayed on the display section 311 on the teaching pendant 300 . When the "Diagnosis" button on the screen (a) is pressed, the robot system shifts to the diagnostic mode, and the display unit 311 displays the screen (b) for diagnostic setting. Here, the user can select the axis for which the reduction gear diagnosis is to be performed, and by pressing the start button, the diagnosis for the selected axis is started.

When finished, the diagnosis result screen (c) of each joint is displayed on the display unit 311 . Here, the % against a predetermined reference value is displayed in the center column, and if it is within 100%, there is no abnormality (OK), and if it exceeds 100%, there is an abnormality (NG). is understood. Also, when the "reference history" button on the diagnostic setting screen is pressed, changes in past diagnostic results are displayed on the graph screen (d), allowing the tendency of diagnostic results on each axis to be understood at a glance.

FIG. 5 is a diagram showing the flow of data during diagnosis. In FIG. 5, the rectangles in the control device 200 represent various control units representing the functions executed by the CPU 216 in terms of hardware, or actual hardware.

The diagnosis mode is activated by an input S312 from the TP operation button 312. FIG. Then, when a joint to be diagnosed is selected, the test motion generation unit 207 generates a test motion corresponding to the joint, or reads an already generated test motion, (S207). Here, the reason why the test operation information S207 is output to the resonance amplitude calculation unit 204 is that the test operation information S207 is used in the data processing in the resonance amplitude calculation unit. The servo control device 201 drives the servo motor 12 by controlling the current S201 based on the output inspection operation information S207. At this time, the input side angle information S8 detected by the input side encoder 8 that detects the rotational position of the motor shaft 4 and the output side angle information S10 of the speed reducer 11 detected by the output shaft encoder 10 are periodically driven. Output to the data recording unit 203 . This time interval is desirably less than ten times the resonance frequency in order to accurately record the resonance amplitude of the robot. For example, when the resonance frequency is 20 Hz, the interval is 200 Hz=5 msec cycle or less.

When the inspection operation is completed, the drive data recording unit 203 outputs the recorded series of angle information S8 and S10 to the resonance amplitude calculation unit 204 as inspection data S203. The resonance amplitude calculator 204 obtains the determination value A from the obtained inspection data S203 and the inspection operation information S207, and outputs it to the reduction gear state determination unit 205 (S204). The reducer state determination unit 205 compares the reference value S206 read from the reference value storage unit 206 with the determination value A (S204), diagnoses the state of the reducer, and displays the diagnosis result S205 on the display unit 311 of the teaching pendant. indicate.

FIG. 6 is a diagram showing a method of generating inspection motions for sweeping a speed range. In step S601, the moment of inertia m applied to the target joint is calculated to obtain the resonance frequency f. Since the resonance frequency f of the robot changes depending on the load and posture of the hand attached to the hand, it is calculated based on them. Next, in step S602, the resonance frequency f of the target joint is calculated from the above equation (1) using the obtained moment of inertia m. Alternatively, the resonance frequency f may be obtained in advance by an experiment under the same conditions.

Next, in step S603, the reduction gear input-side rotational speed R of the target joint that matches 1/2 or an integer multiple of the resonance frequency f obtained in step S602 is calculated, and the corresponding joint motion speed s is obtained. Here, it is desirable that the reducer input-side rotation speed R is set to a value equal to 1/2 of the resonance frequency f. This is derived from the structure of the wave gear reducer. That is, since the flex spline 2 is in contact with the circular spline 3 at two points, two vibrations occur per one rotation of the flex spline. This is because the resonance phenomenon occurs most strongly at a rotation speed at which the resonance frequency and the excitation due to the reduction gear are 1:1, ie, the resonance frequency and the rotation speed on the input side of the reduction gear are 2:1, so that it is easy to measure.

In the next step S604, the speed range is set. This speed range should include the motion speed s of the joint obtained in the previous step S603, and is desirably set within a range that can cover individual differences and variations due to joint states. As the width of this range, a width determined in advance for the apparatus may be applied with the operating speed s as the center. In the next step, a motion speed profile is set that changes the motion speed of the joint over time so as to cover the speed range set in the previous step S604. At this time, it is necessary to adjust the operation time so that the movable range of the target joint does not exceed the allowable range. Also, it is desirable to make the speed change as slow as possible so that the resonance can be measured reliably, so the operating time should be as long as possible.

In addition, although the figure shows a profile that changes linearly from the low speed side to the high speed side of the speed range, it may be a profile that goes from the high speed side to the low speed side, and the change may not be linear. . For example, in the vicinity of the joint velocity s, the velocity may be changed in a non-linear manner such as slowing the velocity change, or the velocity may be discontinuously changed step by step at regular intervals of a relatively short period of time. In other words, it is preferable to provide a period during which the robot arm can change its speed without stopping while moving the robot arm.

The motion for inspection generated in this manner includes the joint velocity s at which the target joint resonates, and can cover a range including individual differences and variations due to joint states in a single motion.

In the description of the present embodiment, it is assumed that s is the operating speed of the joint when it is moved at the speed R on the input side of the speed reducer, and a speed range that includes s is set as an inspection condition. Alternatively, other parameters may be defined . For example, it may be the number of revolutions per unit time of a rotary motor or speed reducer, or the rotation angle of a joint per unit time. That is, if the joint is driven while changing the drive parameter over time so that the operating range includes the condition that the joint resonates, the drive parameter can be read as the drive condition that causes the joint to resonate. good.

FIG. 7 is a diagram showing a flow of performing measurement using the generated inspection motion.

When diagnosing, the robot enters the diagnosis mode by pressing the "diagnosis" button on the UI screen of FIG. 4(a). In step S701, the user designates a joint to be diagnosed using the UI screen shown in FIG. 4B. In step S702, the reference value S206 of the joint selected in step S701 is read, and motions for inspection are generated for each joint according to the flow of FIG. Alternatively, if a generated action is stored, it may be read.

Next, in step S703, in parallel with the execution of the read motion (S703a), the angle value S8 of the input side encoder 8 and the output shaft encoder are calculated while the joint is being driven while the drive parameter is changed over time. The angle value S10 of 10 is recorded in the drive data recording unit 203 (S703b). In S704, it is determined whether or not there is a joint to be inspected. If there is a joint to be inspected, the process returns to step S703, and the execution of the inspection operation and the recording of the angle information are repeated in the same manner. When the inspection motion is completed for all the target joints, data processing, which will be described later, is performed in step S705 to obtain a determination value A. FIG. In step S706, the judgment value A calculated in step S705 and the reference value S206 are compared to diagnose the state of the speed reducer. Finally, in step S707, the diagnostic result is displayed as shown in FIG. 4(c), and the diagnostic mode ends.

FIG. 8 is a diagram showing how the CPU calculates and acquires the determination value A as the maximum value of the vibration amplitude in step S705.

The resonance amplitude calculator 204 calculates the judgment value A from the inspection data S203 sent from the drive data recorder 203 (that is, the difference between the angle information S8 of the input side encoder and the angle information S10 of the output shaft encoder).

By subtracting the angle information S8 of the input shaft from a series of angle information S10 of the output shaft obtained when the target joint is operated according to the created velocity profile, the resonance amplitude as the angle transmission error of the speed reducer is obtained. (Fig. 8). Based on the diagnosis principle described above, the angular transmission error during resonance can be considered to be proportional to the degree of damage occurring in the speed reducer. Since the velocity profile includes the velocity at which the joint to be inspected resonates most, it is possible to forcibly express the angular transmission error in the vibration amplitude due to the resonance. It can also adapt to changes. Therefore, of the calculated angular transmission errors, the maximum value on the plus side or the maximum value on the minus side, whichever is larger (the arrow in FIG. 8), ie, the maximum value of the vibration amplitude, is taken as the judgment value A.

The determination value A obtained as described above and the corresponding reference value S206 are compared by the speed reducer state determination unit 205 . As the reference value to be compared with the judgment value A, for example, there is a method of using the specification value described in the catalog value of the speed reducer. That is, when the specification value set by the reducer manufacturer is exceeded, it is determined that an abnormality has occurred. Alternatively, the positional deviation required for the target joint may be calculated from the required positional accuracy of the hand of the robot arm 101, and the positional deviation may be used as the reference value.

As described above, according to this embodiment, it is possible to diagnose the state of the speed reducer with one inspection operation per joint, regardless of individual differences in robots and variations due to joint states. can be shortened.

12 servo motor (motor)
11 reducer (transmission)
1 web generator 2 flex spline 3 circular spline 8 input side encoder (motor shaft angle detection means)
10 Output shaft encoder (output side angle detection means)
100 robot device 111 to 116 joints 200 control device 216 CPU (arithmetic unit)
217 ROM (storage unit)
300 teaching pendant 311 display unit 203 drive data recording unit 204 resonance amplitude calculation unit 206 reference value storage unit 405 speed reducer state determination unit 207 inspection operation generation unit s8 input side encoder pulse s10 output shaft encoder pulse s203 inspection data s204 judgment value A
s206 Reference value for judgment s207 Operation information for inspection 1000 Robot system

Claims (29)

An information processing method for acquiring information about a robot having joints provided with reduction gears,
displaying on a display unit a predetermined joint that can be selected from among the joints, diagnosing whether or not an abnormality has occurred in a predetermined reduction gear of the selected predetermined joint;
displaying a history of diagnosis results of the predetermined speed reducer on the display unit;
An information processing method characterized by: In the information processing method according to claim 1,
displaying a first button for starting diagnosis of the predetermined speed reducer on the display unit;
An information processing method characterized by: In the information processing method according to claim 1 or 2,
displaying a second button for stopping diagnosis of the predetermined speed reducer on the display unit;
An information processing method characterized by: In the information processing method according to any one of claims 1 to 3,
displaying a fourth button for setting the acquisition of information about the robot on the display unit, and when the fourth button is selected, a setting screen displayed so that the predetermined joint can be selected is displayed;
An information processing method characterized by: In the information processing method according to claim 4,
The setting screen displays a fifth button for displaying the history,
An information processing method characterized by: In the information processing method according to any one of claims 1 to 5,
displaying , on the display unit, as the history, the transition of the diagnosis result of the predetermined speed reducer in a graph;
An information processing method characterized by: In the information processing method according to any one of claims 1 to 6,
displaying a past diagnosis history of the predetermined speed reducer as the history;
An information processing device characterized by: In the information processing method according to any one of claims 1 to 7 ,
displaying, on the display unit , as the history, a graph showing changes in the results of diagnosis of all the reduction gears of the joint;
An information processing method characterized by: In the information processing method according to any one of claims 1 to 8 ,
displaying a sixth button to select all the joints on the display;
An information processing method characterized by: In the information processing method according to any one of claims 1 to 9 ,
displaying the result of the diagnosis of the predetermined speed reducer on the display unit as OK or NG ;
An information processing method characterized by: In the information processing method according to any one of claims 1 to 10 ,
displaying a comparison result with a threshold value as a percentage as a result of diagnosis of the predetermined speed reducer on the display unit ;
An information processing method characterized by: In the information processing method according to claim 11,
The threshold is a specification value described in the catalog of the predetermined speed reducer,
An information processing method characterized by : In the information processing method according to claim 11,
the threshold is a value set based on the positional accuracy of the robot;
An information processing method characterized by : In the information processing method according to any one of claims 1 to 13 ,
emphasizing and displaying the abnormal predetermined speed reducer on the display unit ;
An information processing method characterized by: In the information processing method according to any one of claims 1 to 14 ,
When diagnosing the predetermined speed reducer, the predetermined joint is operated within a range including an operation parameter that causes the strongest natural vibration at the predetermined joint,
An information processing method characterized by: In the information processing method according to claims 1 to 5 ,
sweeping and changing the operating parameter over time;
An information processing method characterized by: In the information processing method according to claim 15 or 16 ,
when diagnosing the predetermined speed reducer, operating the predetermined joint so as not to exceed the movable range of the predetermined joint;
An information processing method characterized by: In the information processing method according to any one of claims 15 to 17 ,
the range corresponds to the natural vibration that changes according to a change in posture of the predetermined joint;
An information processing method characterized by: In the information processing method according to any one of claims 15 to 17 ,
setting a speed as the motion parameter in order to generate the natural vibration most strongly at the predetermined joint, and setting the range so that the speed that is an integral multiple of the natural vibration of the predetermined joint is included in the range;
An information processing method characterized by: In the information processing method according to any one of claims 15 to 17 ,
A speed is set as the motion parameter in order to generate the natural vibration at the predetermined joint most strongly, and the range is set so as to include a speed that is 1/2 times the natural vibration of the predetermined joint. do,
An information processing method characterized by: In the information processing method according to any one of claims 1 to 20 ,
The predetermined joint is provided with a first angle sensor that acquires information about the angle of the output side of the predetermined reduction gear, and a second angle sensor that acquires information about the angle of the input side of the predetermined reduction gear,
diagnosing the predetermined speed reducer based on the first angle sensor and the second angle sensor;
An information processing method characterized by: In the information processing method according to claim 21 ,
Obtaining an amplitude based on the first angle sensor and the second angle sensor, and performing diagnosis of the predetermined speed reducer based on the amplitude;
An information processing method characterized by: In the information processing method according to claim 22,
wherein the amplitude is an angular transmission error in the predetermined speed reducer;
An information processing method characterized by : An information processing device for acquiring information about a robot having joints equipped with reduction gears,
displaying on a display unit a predetermined joint that can be selected from among the joints, diagnosing whether or not an abnormality has occurred in a predetermined reduction gear of the selected predetermined joint;
displaying a history of diagnosis results of the predetermined speed reducer on the display unit;
An information processing device characterized by: A robot system comprising a robot having a joint provided with a speed reducer and a control device for controlling the robot,
The control device
displaying on a display unit a predetermined joint that can be selected from among the joints, diagnosing whether or not an abnormality has occurred in a predetermined reduction gear of the selected predetermined joint;
displaying a history of diagnosis results of the predetermined speed reducer on the display unit;
A robot system characterized by: 26. A method of manufacturing an article, wherein the article is manufactured using the robot system according to claim 25 . A control method for a robot system comprising a robot having a joint provided with a speed reducer and a control device for controlling the robot,
The control device
displaying on a display unit a predetermined joint that can be selected from among the joints, diagnosing whether or not an abnormality has occurred in a predetermined reduction gear of the selected predetermined joint;
displaying a history of diagnosis results of the predetermined speed reducer on the display unit;
A control method characterized by: A program for causing a computer to execute the information processing method according to any one of claims 1 to 23 . A computer-readable recording medium storing the program according to claim 28 .

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