JP7024661B2 - Abnormality judgment method and abnormality judgment device - Google Patents

Description

The present invention relates to an abnormality determination method and an abnormality determination device.

The robot arm operates when it calculates the Cartesian coordinates of the tip position of the robot arm based on the joint angle of the robot arm and determines that the calculated Cartesian coordinates are outside the preset drive range (working range). Has been proposed as a method of monitoring the drive range of the robot arm, which determines that the robot arm is abnormal (see Patent Document 1). The drive range is a range of a part of the movable range of the robot arm, which is preset according to the work content of the robot arm.

Japanese Unexamined Patent Publication No. 8-26492

However, according to the technique described in Patent Document 1, since the abnormality is determined based on whether or not the robot arm exceeds the drive range, an abnormality occurs and the robot arm operates in the non-drive range beyond the drive range. No abnormality can be detected. Therefore, there is a problem that it is not possible to accurately detect an abnormality such as flaking or a sign of failure that tends to occur at the boundary between the drive range and the non-drive range or near the boundary.

The present invention has been made in view of the above problems, and is an abnormality determination capable of accurately detecting an abnormality or a sign of failure of a robot arm such as flaking, which tends to occur at the boundary between a drive range and a non-drive range or near the boundary. A method and an abnormality determination device are provided.

In order to solve the above-mentioned problems, the abnormality determination method and the abnormality determination device according to one aspect of the present invention are the boundary between the drive range and the non-drive range of the movable portion in the movable range of the movable portion provided in the machine. The inspection range including the above is set, and the abnormality of the machine is determined based on the operation data of the machine acquired by operating the movable part over the inspection range.

According to the present invention, it is possible to accurately detect an abnormality or a sign of failure of the robot arm, which tends to occur at the boundary between the drive range and the non-drive range or near the boundary.

FIG. 1 is a block diagram showing a configuration of an abnormality determination device and a production robot to be determined according to an embodiment of the present invention. FIG. 2 is a flowchart showing the operation of the abnormality determination device according to the embodiment of the present invention. FIG. 3 is a schematic diagram showing the drive range of the movable portion. FIG. 4 is a schematic diagram showing an inspection range set for the drive range shown in FIG. FIG. 5 is a schematic diagram showing the drive range of the movable portion after changing the operation pattern.

Next, embodiments of the present invention will be described in detail with reference to the drawings. In the description, the same reference numerals are given and duplicate description is omitted.

FIG. 1 is a block diagram showing a configuration of an abnormality determination device and a production robot to be determined according to the present embodiment.

The abnormality determination device 100 is connected wirelessly or by wire so as to be able to communicate with the production robot 40 (machine). The abnormality determination device 100 determines whether or not a machine provided with a movable portion is abnormal. For example, a production robot 40 (machine), which is a multi-axis machine having one or more joints, is targeted for determination. It is determined whether or not the production robot 40 is abnormal. The production robot 40 is, for example, a robot that includes a plurality of movable parts and executes welding work of a vehicle body.

In this embodiment, it is assumed that the "work" performed by the production robot 40 (for example, work related to production such as welding work, painting work, and assembly work of parts) has already been defined. Further, it is assumed that the operation pattern of the production robot 40 and the robot control information that realizes the operation pattern have already been determined according to the "work" performed by the production robot 40. In the present invention, the abnormality determination is performed on the production robot 40 for which the "work" is defined in this way. In the following, the term "work" performed by the production robot 40 is used to mean that the process at the time of abnormality diagnosis is not included.

[Production robot configuration]
The movable part of the production robot 40 is connected to a control drive part (not shown). When the control drive unit is driven based on the robot control information, the movable unit operates by the control drive force output by the control drive unit. The production robot 40 is configured to operate in various motion patterns by combining the motions of the movable parts realized based on the robot control information.

As shown in FIG. 3, the production robot 40 has a work execution unit 250, and the work execution unit 250 touches or touches a target object to be worked on in the middle of an operation pattern realized based on robot control information. Work is done in close proximity. In FIG. 3, two postures, a posture shown by a solid line and a posture shown by a two-dot chain line, are exemplified as the postures of the production robot 40 realized during the motion pattern.

For example, when the work of the production robot 40 is a welding work, a welding machine is attached to the tip of the production robot 40 as a work execution unit 250, and the production robot 40 places the work execution unit 250 at the welding point before the welding is performed. An operation pattern is performed in which the work execution unit 250 is moved away from the welded portion after the work execution unit 250 is brought into contact with or brought close to each other. When the work of the production robot 40 is the work of assembling parts, a robot hand is attached to the tip of the production robot 40 as a work execution unit 250, and between the parts storage place beside the production robot 40 and the assembly target location. , Perform an operation pattern for reciprocating the work execution unit 250.

Further, as shown in FIG. 3, the production robot 40 includes a work arm 240 as a movable portion. The working arm 240 rotates about the rotation axis 201 by the control driving force output from the control drive unit. In the present embodiment, the movable portion will be described as rotating around the center of the joint as a fulcrum, but the movable portion is not limited to rotation, and may be a linear motion or a motion that draws a curved locus. ..

The production robot 40 includes a communication circuit 41 and a sensor 43. The sensor 43 is installed at or near the position of the movable portion or the control drive portion in order to quantitatively detect the state of the production robot 40. The sensor 43 may be, for example, a camera that captures an image or a moving image, an optical sensor, a sound sensor, an acceleration sensor, a vibration sensor, a pressure sensor, a strain sensor, an acoustic emission sensor, a temperature sensor, a humidity sensor, or the like. You may. In addition, the sensor 43 may be a position sensor that measures the position of the movable portion, a sensor that measures the control driving force, torque, or the like generated by the control drive unit.

The communication circuit 41 transmits the operation data of the production robot 40 obtained by the sensor 43 to the abnormality determination device 100. The operation data of the production robot 40 may be the data itself (so-called raw data) obtained by the sensor 43, or the data obtained by analyzing the data obtained by the sensor 43 by an arithmetic circuit or the like (not shown). There may be. Further, the operation data of the production robot 40 may include information on the time when the data is acquired by the sensor 43 (time stamp such as date and time) and information on the operation trajectory of the movable portion.

The data transmitted by the communication circuit 41 to the abnormality determination device 100 may include data such as the type, load amount, and frequency of the work performed by the production robot 40, and maintenance (repair, parts of the production robot 40) of the production robot 40 may be included. Maintenance data (maintenance history, maintenance location information) indicating that maintenance has been performed may be included when replacement (replacement of lubricating oil, etc.) is performed.

[Configuration of abnormality determination device]
The abnormality determination device 100 includes a communication circuit 50, a storage unit 60, a processing unit 70 (controller), and a notification unit 80. The processing unit 70 is connected to the communication circuit 50, the storage unit 60, and the notification unit 80 so as to be able to communicate with each other.

The communication circuit 50 is connected wirelessly or by wire so as to be able to communicate with the communication circuit 41 of the production robot 40. The communication circuit 50 receives operation data of the production robot 40 from the communication circuit 41 of the production robot 40. In addition, the communication circuit 50 may receive data such as the type, load amount, and frequency of work performed by the production robot 40, and maintenance data.

The data received by the communication circuit 50 is stored in the storage unit 60. The data stored in the storage unit 60 is read out by the processing unit 70 when the abnormality determination process is executed. The storage unit 60 may store data such as the type, load amount, and frequency of the work performed by the production robot 40 in association with the operation data of the production robot 40. May be stored in association with the maintenance data of the production robot 40.

In addition, the storage unit 60 stores robot control information that realizes the work performed by the production robot 40. The storage unit 60 may store one robot control information for one work performed by the production robot 40.

Further, the storage unit 60 may store a plurality of robot control information for one operation. In this case, in the operation pattern realized by the robot control information, the position of the work execution unit 250 when performing the work is the same among the plurality of robot control information. On the other hand, since the plurality of robot control information realizes operation patterns of the production robots 40 that are different from each other, the operation of the movable portion in the operation pattern does not necessarily match among the plurality of robot control information.

In addition, when the work of the production robot 40 is changed (for example, when the usage of the production robot 40 used for painting is changed to the welding purpose), the storage unit 60 is changed to the work before the change. Instead of the corresponding robot control information, the robot control information corresponding to the changed work may be newly stored.

The processing unit 70 controls the operation of the production robot 40, and further determines an abnormality of the production robot 40 based on the operation status of the production robot 40 and the like. Details of the processing unit 70 will be described later.

When the processing unit 70 determines that the production robot 40 is abnormal, the notification unit 80 issues an abnormality alarm based on a command from the processing unit 70 and detects the abnormality in the observer or maintenance personnel. Let me know. For example, the notification unit 80 is a rotating light, a buzzer, or the like.

[Configuration of processing unit]
The processing unit 70 (an example of a control unit or a controller) is a general-purpose microcomputer including a CPU (central processing unit), a memory, and an input / output unit. A computer program (abnormality determination program) for functioning as a part of the abnormality determination device 100 for determining an abnormality of the production robot 40 is installed in the processing unit 70. By executing the computer program, the processing unit 70 functions as a plurality of information processing circuits (71, 73, 75, 77, 79) included in the abnormality determination device 100.

In this embodiment, an example of realizing a plurality of information processing circuits (71, 73, 75, 77, 79) by software is shown. However, it is also possible to configure an information processing circuit (71, 73, 75, 77, 79) by preparing dedicated hardware for executing each of the following information processing. Further, a plurality of information processing circuits (71, 73, 75, 77, 79) may be configured by individual hardware. Further, the information processing circuit (71, 73, 75, 77, 79) may also be used as a control unit used for monitoring or controlling the production robot 40.

The processing unit 70 includes an operation control unit 71, a drive range detection unit 73, an inspection range setting unit 75, an abnormality diagnosis instruction unit 77, and a plurality of information processing circuits (71, 73, 75, 77, 79). It is provided with an abnormality determination unit 79.

The drive range detection unit 73 operates the movable unit according to the operation pattern of the production robot 40 based on the robot control information provided to the production robot 40 or the robot control information stored in the storage unit 60. Detect the drive range.

As an example, consider a production robot 40 in which movable parts are connected to each other via joints as shown in FIG. The work arm 240, which is a movable portion, is connected to the arm support portion 230 via the rotation shaft 201, and the work arm 240 is fixed to the arm support portion 230 so that the rotation movement can be performed with the rotation shaft 201 as a fulcrum. Has been done. In addition, the movable parts of the rotating shaft 202 and the rotating shaft 203 are similarly connected to each other. The production robot 40 shown in FIG. 3 has joints at the positions of the rotary shaft 201, the rotary shaft 202, and the rotary shaft 203.

In FIG. 3, considering the polar coordinates whose origin is the point through which the rotary axis 201 passes in the plane perpendicular to the rotary axis 201, the angular coordinates of the polar coordinates are set as the coordinates θ, and the counterclockwise direction is the coordinate θ around the rotary axis 201. The direction is to increase. In the example shown in FIG. 3, the working arm 240 is assumed to operate in the range of the coordinate θ such that “α1 ≦ θ ≦ α2” (however, α1 <α2).

In the robot control information that describes the operation pattern of the production robot 40, if the position of the work arm 240 is expressed by the coordinate θ, for example, "increase the coordinate θ from the value α1 to the value α2" or "coordinate θ". The operation of the work arm 240 is expressed by the robot control information "decrease from the value α2 to the value α1".

Therefore, the drive range detection unit 73 detects that the range in which the work arm 240 operates is the drive range W1 by referring to the robot control information. When the drive range W1 can be detected, the drive range detection unit 73 can recognize that the range excluding the drive range W1 of the movable range of the movable unit is the non-drive range, and further, the drive range W1 of the work arm 240 and the drive range W1. It can be recognized that the boundary between the non-driving ranges is at two positions, that is, the position where “θ = α1” and the position where “θ = α2”.

In the above example, the drive range detection unit 73 has been described as detecting the drive range in which the movable unit operates according to the operation pattern of the production robot 40 based on the robot control information, but the method is not limited to this method. For example, the drive range detection unit 73 can also detect the drive range of the movable portion by monitoring the range in which the movable portion operates with a sensor 43 or the like while the production robot 40 is performing the work.

Further, in the above example, the "boundary" between the driven range and the non-driven range is expressed as the position where the variable representing the position of the movable portion takes a specific value as described above. However, in the actual operation of the production robot 40, it depends on the meshing condition of the gear when the control driving force is transmitted to the moving part by the gear or the like, the processing accuracy of the part, the state of wear of the part, and the like. Therefore, the position of the "boundary" may fluctuate slightly. Therefore, it should be noted that in the actual operation of the production robot 40, it is more appropriate to regard the "boundary" as a range having a width determined by the above-mentioned error.

Further, the drive range, the non-drive range, and the boundary are described by using the angular coordinates corresponding to the rotational movement of the movable portion, but the present invention is not limited thereto. In addition, when the movable part makes a linear motion or a motion that draws a curved locus, the drive range, the non-drive range, and the boundary should be described in the same manner by using the coordinates corresponding to the motion. Can be done.

The inspection range setting unit 75 sets the inspection range including the boundary between the drive range and the non-drive range based on the drive range detected by the drive range detection unit 73 for the abnormality diagnosis of the production robot 40. Set in.

In other words, the inspection range setting unit 75 sets the inspection range so as to straddle the boundary between the drive range and the non-drive range. The inspection range is set to have a predetermined width around the boundary between the driven range and the non-driven range.

As shown in FIG. 4, the inspection range setting unit 75 sets the inspection range R1 indicated by the range of the coordinate θ such that “β11 ≦ θ ≦ β12” with respect to the boundary at the position “θ = α1”. For the boundary at the position “θ = α2”, the inspection range R2 indicated by the range of the coordinate θ such that “β21 ≦ θ ≦ β22” is set. The inspection range R1 includes a boundary at the position “θ = α1”, and the inspection range R2 includes a boundary at the position “θ = α2”.

The inspection range to be set may be set to include only a part of the boundary between the driven range and the non-driven range. In the above example, the inspection range R1 includes the boundary at the position “θ = α1” but does not include the boundary at the position “θ = α2”. Similarly, the inspection range R2 includes the boundary at the position “θ = α2” but does not include the boundary at the position “θ = α1”. Therefore, the set inspection range R1 and inspection range R2 are set to include only a part of the boundary between the drive range and the non-drive range.

Further, the inspection range to be set may be set to include the entire boundary between the driven range and the non-driven range. Although not shown in the above example, it corresponds to the case where the inspection range is set so as to include both the boundary at the position “θ = α1” and the boundary at the position “θ = α2”.

The width of the inspection range set by the inspection range setting unit 75 may be set as a width of about 10% of the width of the drive range. Furthermore, when the control driving force is transmitted to the moving part by the gear, the inspection range is set based on the number of teeth of the gear, and the larger the number of teeth, the smaller the width of the inspection range is set. You may. The reason for setting in this way is that in the actual operation scene of the production robot 40, the position of the boundary between the drive range and the non-drive range is the meshing condition of the gear, the processing accuracy of the part, the state of wear of the part, and the like. This is to ensure that the inspection range is set so as to surely include the boundary.

The abnormality diagnosis instruction unit 77 transmits an operation start command for abnormality diagnosis to the operation control unit 71 on the premise that the inspection range is set by the inspection range setting unit 75.

The abnormality diagnosis instruction unit 77 may receive an instruction to start the abnormality diagnosis from the observer or the maintenance staff via a user interface (not shown) or the like, and when there is an instruction from the observer or the maintenance staff. In addition, the operation start command for abnormality diagnosis may be transmitted to the operation control unit 71. The abnormality diagnosis instruction unit 77 may send an operation start command for abnormality diagnosis to the operation control unit 71 at the timing of the hibernation state in which the production robot 40 is not performing work.

The motion control unit 71 controls the production robot 40 to perform an operation for the abnormality diagnosis in response to a command from the abnormality diagnosis instruction unit 77 to start the operation for the abnormality diagnosis. More specifically, the motion control unit 71 controls the movable unit to operate over the set inspection range. While the movable portion is operated over the inspection range, the operation data of the production robot 40 is acquired by the sensor 43 and transmitted to the abnormality determination device 100 via the communication circuit 41.

According to the example shown in FIG. 4, the motion control unit 71 “increases the coordinate θ from the value β11 to the value β12” or “sets the coordinate θ” in order to operate the work arm 240, which is a movable unit, in the inspection range R1. The robot control information "decrease from the value β12 to the value β11" is transmitted. Further, the motion control unit 71 operates the work arm 240 in the inspection range R2, so that the robot "increases the coordinate θ from the value β21 to the value β22" or "decreases the coordinate θ from the value β22 to the value β21". Send control information.

When the motion control unit 71 operates the movable unit over the inspection range, the movable unit may be controlled to move at a constant velocity or at a constant acceleration.

According to the example shown in FIG. 4, the motion control unit 71 may control the work arm 240 to perform an equiangular velocity motion or an equiangular acceleration motion with the rotation axis 201 as a fulcrum. That is, it may be controlled so that the time first-order derivative or the time second-order derivative of the coordinate θ indicating the position of the work arm 240 is constant.

The abnormality determination unit 79 determines the abnormality of the production robot 40 based on the operation data acquired by operating the movable unit over the inspection range.

There are various methods for determining an abnormality performed by the abnormality determination unit 79. For example, the abnormality determination unit 79 determines that a part of the operation data (for example, the acceleration value acquired by the acceleration sensor) is "normal" if it is less than the threshold value, and "abnormal" if it is more than the threshold value. This threshold value may be estimated in advance from data such as an experiment, or may be determined by using a statistical test value, a Mahalanobis distance, or the like.

The abnormality determination unit 79 compares the first data when there is a movable part in the drive range and the second data when there is a movable part in the non-drive range among the operation data, and the abnormality determination unit 79 compares the abnormality of the production robot 40. May be used to determine. If there is no significant difference between the two data, it may be determined as "normal", and if there is a significant difference, it may be determined as "abnormal". Further, the normality / abnormality of the production robot 40 may be determined based on whether or not the ratio of both data is equal to or higher than the threshold value.

Further, the abnormality determination unit 79 compares the first data when there is a movable part in the drive range and the boundary data when there is a movable part at the boundary position among the operation data, and compares the operation data with the boundary data of the production robot 40. It may be used to determine an abnormality. Further, the abnormality determination unit 79 compares the second data when there is a movable part in the non-driving range and the boundary data when there is a movable part at the boundary position among the operation data, and the production robot 40. It may be the one that determines the abnormality of. As a method for comparing data, the same method as in the case of comparing the first data and the second data described above can be used.

Further, when a plurality of inspection ranges can be set by the inspection range setting unit 75, the abnormality determination unit 79 has the third data when there is a movable part in one inspection range and the case where there is a movable part in another inspection range. The fourth data of the above may be compared with the fourth data of the above to determine the abnormality of the production robot 40. As a method for comparing data, the same method as in the case of comparing the first data and the second data described above can be used.

The configuration of the processing unit 70 is as described above, but when the abnormality determination unit 79 determines the abnormality of the production robot 40, the processing unit 70 may execute the processing at the time of abnormality. As the abnormality processing, for example, the notification unit 80 may issue an abnormality alarm to notify the observer or the maintenance member that the abnormality has been detected.

As the processing at the time of abnormality, the processing for excluding the robot control information in which the movable part may operate at or near the boundary used for the abnormality determination from the robot control information used when the production robot 40 is made to perform a specific work. It may be the one that performs. By using the robot control information not excluded by the process when executing the work of the production robot 40, it is possible to avoid the problem that the movable part does not operate normally, and further, near the boundary where the abnormality occurs. It is possible to prevent the abnormal state from getting worse.

For example, when it is determined that the production robot 40 is abnormal at either the boundary at the position “θ = α1” or the boundary at the position “θ = α2” shown in FIG. 4, the drive range W1 By continuing to operate the work arm 240 further, the abnormal state may be aggravated. Therefore, instead of the operation pattern (first operation pattern) in which the work arm 240 operates in the drive range W1, the operation pattern (second operation pattern) in which the work arm 240 does not operate in the drive range W1 is used. It is desirable to do. Therefore, the robot control information for operating the work arm 240 in the drive range W1 is excluded, and the robot control information for operating the work arm 240 in the drive range W2 as shown in FIG. 5 is used as alternative robot control information. , Give instructions to the production robot 40.

Comparing the first operation pattern and the second operation pattern, the position of the work execution unit 250 when performing the work in the second operation pattern is the same as the position of the work execution unit 250 when performing the work in the first operation pattern. Is. On the other hand, the drive range W2 (second drive range) of the work arm 240 determined by the second operation pattern is different from the drive range W1 (first drive range) of the work arm 240 determined by the first operation pattern.

[Abnormality judgment processing procedure]
Next, the flowchart of FIG. 2 will explain an example of the abnormality determination processing procedure according to the present embodiment. FIG. 2 is a flowchart showing the operation of the abnormality determination device according to the embodiment of the present invention. The abnormality determination process shown in FIG. 2 is started when an instruction to start the abnormality diagnosis is given by a watchman or a maintenance worker, or at a predetermined timing during the period when the production robot 40 is activated.

First, in step S101, the drive range detection unit 73 acquires the robot control information provided to the production robot 40 or the robot control information stored in the storage unit 60.

In step S103, the drive range detection unit 73 detects the drive range in which the movable unit operates based on the acquired robot control information. In the operation pattern realized when the production robot 40 operates based on the acquired robot control information, the robot control information and the drive range are related to each other in that the movable portion operates the drive range.

Further, the drive range detection unit 73 detects the drive range of the movable portion, recognizes the range of the movable portion excluding the drive plate as the non-drive range, and further recognizes the drive range and the non-drive range. Recognize the boundaries between them.

In step S105, the inspection range setting unit 75 sets the inspection range so as to straddle the boundary between the drive range and the non-drive range. That is, the inspection range setting unit 75 sets a part of the movable range as the inspection range so as to include the boundary.

In step S107, the abnormality diagnosis instruction unit 77 transmits an operation start command for abnormality diagnosis to the operation control unit 71. The motion control unit 71 controls the movable unit to operate over the set inspection range.

In step S109, the operation data of the production robot 40 is acquired by the sensor 43 while the movable portion is operated over the inspection range. The acquired operation data is transmitted to the abnormality determination device 100 via the communication circuit 41 as sensor information.

In step S111, the abnormality determination unit 79 determines the abnormality of the production robot 40 based on the operation data acquired by operating the movable unit over the inspection range.

If it is determined that the production robot 40 is abnormal (YES in step S111), the process proceeds to step S113, and the processing unit 70 executes the abnormal processing.

When it is determined that the production robot 40 is not abnormal (NO in step S111), or after the abnormality processing is executed in step S113, the abnormality determination process shown in FIG. 2 ends.

[Effect of embodiment]
As described in detail above, according to the abnormality determination method and the abnormality determination device according to the present embodiment, the inspection range including the boundary between the drive range and the non-drive range of the movable portion is set within the movable range. , The moving part is operated over the inspection range to acquire the operation data of the machine, and the abnormality of the machine is determined based on the acquired operation data.

As a result, since the movable portion is moved so as to straddle the boundary between the drive range and the non-drive range, the abnormality detection omission at the boundary and the vicinity of the boundary can be prevented, and the abnormality detection performance can be further improved. It is possible to detect abnormalities such as flaking and failures at and near the boundary. Therefore, it is possible to accurately detect a machine abnormality or a sign of failure.

For example, the boundary between the drive range and the non-drive range and the vicinity of the boundary are places where deceleration / acceleration of the gears that operate the joints of the robot arm are likely to occur, and abnormalities such as flaking and failures are likely to occur, but within the drive range. With the method of monitoring only the operation of, it is not possible to compare with the operation outside the drive range where flaking is unlikely to occur. On the other hand, according to the abnormality determination method and the abnormality determination device according to the present embodiment, since the movable portion is moved so as to straddle the boundary between the drive range and the non-drive range, the operation is outside the drive range where flaking is unlikely to occur. It is possible to make comparisons and accurately detect signs of machine abnormalities and failures.

Further, according to the abnormality determination method and the abnormality determination device according to the present embodiment, the inspection range may be set so as to have a width of a predetermined range around the boundary. By setting the inspection range with a predetermined width, the boundary and the vicinity of the boundary are to be diagnosed, and the measurement results when the movable part is present in the other range are less likely to be mixed. As a result, the signal can be stably acquired by the sensor, and the abnormality detection performance can be improved. Furthermore, it is possible to perform anomaly determination specialized for anomalies and failures that are likely to occur at the boundary and in the vicinity of the boundary.

Further, according to the abnormality determination method and the abnormality determination device according to the present embodiment, the inspection range may be set to have a width of about 10% of the width of the drive range. The boundary and the vicinity of the boundary can be more reliably diagnosed, and the abnormality detection performance can be improved. Furthermore, it is possible to perform anomaly determination specialized for anomalies and failures that are likely to occur at the boundary and in the vicinity of the boundary.

Further, according to the abnormality determination method and the abnormality determination device according to the present embodiment, when the control driving force is transmitted to the moving portion by the gear, the inspection range is set based on the number of teeth of the gear, and the number of teeth is increased. The larger the number, the smaller the width of the inspection range may be set.

Considering that the position of the boundary between the drive range and the non-drive range may change depending on the meshing condition of the gear in the actual operation scene of the production robot 40, the larger the number of teeth of the gear, the position of the boundary. The fluctuation range is small. Therefore, when the number of teeth of the gear is large, even if the width of the inspection range is set to be small, the boundary and the vicinity of the boundary can be reliably set as the diagnosis target. Furthermore, it becomes difficult for the measurement results to be mixed when the movable portion exists in a range other than the range such as the boundary or the vicinity of the boundary.

Further, according to the abnormality determination method and the abnormality determination device according to the present embodiment, among the operation data, the first data when there is a movable part in the drive range and the second data when there is a movable part in the non-drive range. And, may be compared to determine the abnormality of the machine. It is more accurate because it is possible to judge anomalies by using global data, which is difficult with the method of judging anomalies from local data, targeting only the data when the moving part is at the boundary position. Abnormality can be determined. Furthermore, by clarifying the gap between the case where the movable part is in the drive range and the case where the movable part is at the boundary position, it is possible to grasp the overall state of abnormality and improve the abnormality detection performance. Can be improved.

Further, according to the abnormality determination method and the abnormality determination device according to the present embodiment, when a plurality of inspection ranges can be set, the third data when there is a movable part in one inspection range among the plurality of inspection ranges, and a plurality of data. It may be the one that determines the abnormality of the machine by comparing with the fourth data in the case where there is a movable part in another inspection range in the inspection range of.

When multiple inspection ranges can be set, it corresponds to the case where there are multiple boundaries. The load on the moving part may differ from boundary to boundary, and the degree of abnormal condition that occurs at the boundary may also differ. By comparing the data for each boundary, the abnormality detection performance can be improved. Furthermore, it is possible to clarify the tendency of the abnormality and facilitate the identification of the cause of the abnormality.

Further, according to the abnormality determination method and the abnormality determination device according to the present embodiment, when the movable part rotates in the movable range, the movable part is moved at an equal velocity or an equal acceleration over the inspection range to acquire operation data. It may be a thing. In this case, since the angular velocity or angular acceleration of the movable part when the movable part passes through the boundary and the vicinity of the boundary can be made constant, the signal can be stably acquired by the sensor, and the abnormality detection performance is improved. be able to. In addition, noise entering the acquired signal can be reduced.

Further, according to the abnormality determination method and the abnormality determination device according to the present embodiment, when the movable part moves linearly in the movable range, the movable part is moved at a constant velocity or a constant acceleration over the inspection range to acquire operation data. It may be. In this case, since the speed or acceleration of the moving part when the moving part passes through the boundary and the vicinity of the boundary can be made constant, the signal can be stably acquired by the sensor, and the abnormality detection performance is improved. Can be done. In addition, noise entering the acquired signal can be reduced.

Further, according to the abnormality determination method and the abnormality determination device according to the present embodiment, the operation data may be stored in association with the time when the operation data is acquired. Since the change of the abnormality can be grasped along the time series, the change point of the abnormality can be detected and the abnormality detection performance can be improved.

Further, according to the abnormality determination method and the abnormality determination device according to the present embodiment, the operation data may include information on the operation locus of the movable portion. As a result, the abnormality can be determined in association with the operation locus, so that the abnormality detection performance can be improved. Furthermore, it is possible to clarify the tendency of the abnormality and facilitate the identification of the cause of the abnormality.

Further, according to the abnormality determination method and the abnormality determination device according to the present embodiment, the operation data may be stored by associating at least one of the type, load amount, and frequency of the work performed by the machine. .. Since the abnormality can be determined in association with the type, load amount, frequency, etc. of the work performed by the machine, the abnormality detection performance can be improved. Furthermore, it is possible to clarify the tendency of the abnormality and facilitate the identification of the cause of the abnormality.

Further, according to the abnormality determination method and the abnormality determination device according to the present embodiment, the operation data may be stored by associating the maintenance history or the maintenance location of the machine. Since maintenance data such as machine maintenance history or maintenance location can be used for abnormality determination, it is possible to generate a probability distribution based on the past abnormality occurrence situation, and it is possible to improve the abnormality detection performance.

Further, according to the abnormality determination method and the abnormality determination device according to the present embodiment, the movable portion may be a working arm. Further, the machine may include at least one joint, and the working arm may rotate around the center of the joint as a fulcrum. Since the abnormality determination is performed only on the work arm among the movable parts constituting the machine, the abnormality determination can be performed more efficiently than when a plurality of movable parts are included, and the abnormality detection performance can be improved.

Further, according to the abnormality determination method and the abnormality determination device according to the present embodiment, the joint provided in the machine is a speed reducer assembled to the motor, and the operation data includes at least the gear position in the speed reducer. It may be a thing. Since the gear position information can be used for abnormality determination, the boundary position can be specified more accurately, and fine abnormality detection can be performed with more detailed spatial resolution. As a result, the abnormality detection performance can be improved.

Further, when it is determined that the machine having the work execution unit is abnormal when operating in the first operation pattern based on the abnormality determination method and the abnormality determination device according to the present embodiment, it is different from the first operation pattern. In the control method and control device that controls the machine so that it operates in the second operation pattern, the position of the work execution unit when performing the work in the second operation pattern is the work execution unit when performing the work in the first operation pattern. The second drive range of the movable portion determined by the second operation pattern may be different from the first drive range of the movable portion determined by the first operation pattern.

As a result, by changing the drive range of the movable part other than the work execution part while keeping the position of the work execution part based on the boundary abnormality detection result, the drive range overlaps with the boundary used for the abnormality determination or its vicinity. You can avoid it.

In particular, among the robot control information used when making the machine perform work, the robot control information in which the movable part may operate at or near the boundary used for abnormality determination was excluded, and was not excluded by the processing. By using the robot control information for controlling the machine, it is possible to avoid the problem that the moving parts do not operate normally.

Furthermore, it is possible to prevent the boundary where the abnormality is occurring and the abnormal state near the boundary from further worsening. As a result, it is possible to reduce the probability that the target location for abnormality determination will fail.

Each of the functions shown in the above embodiments may be implemented by one or more processing circuits. Processing circuits include programmed processors, electrical circuits, etc., as well as devices such as application specific integrated circuits (ASICs) and circuit components arranged to perform the described functions. Etc. are also included.

Although the contents of the present invention have been described above according to the embodiments, it is obvious to those skilled in the art that the present invention is not limited to these descriptions and can be modified and improved in various ways. The statements and drawings that form part of this disclosure should not be understood as limiting the invention. This disclosure will reveal to those skilled in the art various alternative embodiments, examples and operational techniques.

It goes without saying that the present invention includes various embodiments not described here. Therefore, the technical scope of the present invention is defined only by the matters specifying the invention relating to the reasonable claims from the above description.

40 Production robot 41 Communication circuit 43 Sensor 50 Communication circuit 60 Storage unit 70 Processing unit 71 Operation control unit 73 Drive range detection unit 75 Inspection range setting unit 77 Abnormality diagnosis instruction unit 79 Abnormality judgment unit 80 Notification unit 100 Abnormality determination device 201, 202 , 203 Rotating shaft 230 Arm support 240 Work arm 250 Work execution unit R1, R2 Inspection range W1, W2 Drive range

Claims (17)

It is an abnormality determination method for determining an abnormality of the machine, which performs a predetermined work by operating the movable portion within a predetermined drive range within the movable range of the movable portion provided in the machine.
The range excluding the drive range from the movable range is set as the non-drive range, and the inspection range including the boundary between the drive range and the non-drive range is set within the movable range.
The movable part is operated over the inspection range to acquire the operation data of the machine, and the operation data is acquired.
Judging the abnormality of the machine based on the acquired operation data,
An abnormality determination method characterized by. The abnormality determination method according to claim 1.
The abnormality determination method, wherein the inspection range is set so as to have a width of a predetermined range around the boundary. The abnormality determination method according to claim 2.
The abnormality determination method, wherein the inspection range is set to have a width of about 10% of the width of the drive range. The abnormality determination method according to claim 2.
When the control driving force is transmitted to the movable part by the gear,
The inspection range is set based on the number of teeth of the gear.
An abnormality determination method characterized in that the width of the inspection range is set smaller as the number of teeth is larger. The abnormality determination method according to any one of claims 1 to 4.
Among the operation data, the first data when the movable part is in the drive range and the second data when the movable part is in the non-drive range are compared to determine the abnormality of the machine. An abnormality determination method characterized by performing. The abnormality determination method according to any one of claims 1 to 5.
If multiple inspection ranges can be set
The third data when the movable part is in one of the plurality of inspection ranges and the case where the movable part is in the other inspection range among the plurality of inspection ranges different from the third data. An abnormality determination method, characterized in that an abnormality of the machine is determined by comparing with the fourth data of the above. The abnormality determination method according to any one of claims 1 to 6.
When the movable part rotates in the movable range,
An abnormality determination method, characterized in that the moving portion is moved at an equal angular velocity or an equal acceleration to acquire the operation data over the inspection range. The abnormality determination method according to any one of claims 1 to 6.
When the movable part moves linearly in the movable range,
An abnormality determination method, characterized in that the moving portion is moved at a constant velocity or a constant acceleration over the inspection range to acquire the operation data. The abnormality determination method according to any one of claims 1 to 8.
An abnormality determination method characterized in that the operation data is stored in association with the time when the operation data is acquired. The abnormality determination method according to any one of claims 1 to 9.
An abnormality determination method, characterized in that the operation data includes information on an operation locus of the movable portion. The abnormality determination method according to any one of claims 1 to 10.
An abnormality determination method characterized in that operation data is stored by associating at least one of the type, load amount, and frequency of the work performed by the machine. The abnormality determination method according to any one of claims 1 to 11.
An abnormality determination method characterized in that the operation data is stored by associating the maintenance history or maintenance location of the machine. The abnormality determination method according to any one of claims 1 to 12.
An abnormality determination method characterized in that the movable portion is a work arm. The abnormality determination method according to claim 13, wherein the abnormality is determined.
The machine has at least one joint and
The abnormality determination method, wherein the working arm rotates around the center of the joint as a fulcrum. The abnormality determination method according to claim 14, wherein the abnormality is determined.
The joint is a speed reducer attached to the motor.
An abnormality determination method, characterized in that the operation data includes at least a gear position in the speed reducer. A second operation pattern different from the first operation pattern when it is determined that the machine operating in the first operation pattern is abnormal based on the abnormality determination method according to any one of claims 1 to 15. It is a control method that controls the machine so that it operates according to an operation pattern.
The machine has a work execution unit that performs the work.
The position of the work execution unit when performing the work in the second operation pattern is the same as the position of the work execution unit when performing the work in the first operation pattern.
A control method characterized in that the second drive range of the movable portion determined by the second operation pattern is different from the first drive range of the movable portion determined by the first operation pattern. An abnormality determination device for determining an abnormality in a machine that performs a predetermined operation by operating the movable portion within a predetermined drive range within the movable range of the movable portion provided in the machine.
A controller for controlling the machine is provided.
The controller
The range excluding the drive range from the movable range is set as the non-drive range, and the inspection range including the boundary between the drive range and the non-drive range is set within the movable range.
The movable part is operated over the inspection range to acquire the operation data of the machine, and the operation data is acquired.
Judging the abnormality of the machine based on the acquired operation data,
An abnormality determination device characterized by.

Images