JP2020028941A - Abnormality determination method and abnormality determination device - Google Patents

Abstract

To provide an abnormality determination method and an abnormality determination device capable of detecting a sign of abnormality and a failure of a robot arm, which easily occurs at or near a boundary between a driving range and a non-driving range with high accuracy.SOLUTION: An abnormality determination method and an abnormality determination device set an inspection range including a boundary between of a driving range and a non-driving range of a movable part in a movable range of the movable part provided by a machine, and determine abnormality of the machine on the basis of operation data of the machine.SELECTED DRAWING: Figure 2

Description

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

  The orthogonal coordinates of the robot arm tip position are calculated based on the joint angle of the robot arm, and when it is determined that the calculated orthogonal coordinates are outside the preset driving range (working range), the operation of the robot arm is performed. A method for monitoring the drive range of a robot arm that determines that the robot arm is abnormal has been proposed (see Patent Document 1). The drive range is a part of the movable range of the robot arm, which is set in advance according to the work content of the robot arm.

JP-A-8-26492

  However, according to the technology described in Patent Literature 1, the abnormality is determined based on whether the robot arm has exceeded the drive range. Therefore, an abnormality has occurred and the robot arm operates beyond the drive range and operates in the non-drive range. Unable to detect abnormalities. For this reason, there is a problem in that it is not possible to accurately detect an abnormality such as flaking or a sign of a failure which is likely 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-described problems, and is an abnormality determination that can accurately detect an abnormality or a sign of a failure of a robot arm such as flaking that is likely to occur at or near a boundary between a driving range and a non-driving range. A method and an abnormality determination device are provided.

  In order to solve the above-described problem, an abnormality determination method and an abnormality determination device according to one embodiment of the present invention provide a method for determining a boundary between a driving range of a movable unit and a non-driving range of a movable range of a movable unit included in a machine. 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 a sign of an abnormality or failure of the robot arm, which is likely to occur at the boundary between the driving range and the non-driving range or near the boundary.

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

  Next, an embodiment of the present invention will be described in detail with reference to the drawings. In the description, the same components will be denoted by the same reference symbols, without redundant description.

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

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

  In the present embodiment, it is assumed that the “work” performed by the production robot 40 (for example, a work related to production, such as a welding work, a painting work, and a part assembling work) has been determined. Furthermore, it is assumed that the operation pattern of the production robot 40 and the robot control information for realizing 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 in which the “work” is determined as described above. In the following, the term “work” performed by the production robot 40 is used in a sense that does not include processing at the time of abnormality diagnosis.

[Configuration of production robot]
The movable part of the production robot 40 is connected to a braking / driving part (not shown). When the braking / driving unit is driven based on the robot control information, the movable unit operates by the braking / driving force output by the braking / driving unit. The production robot 40 is configured to operate in various operation patterns by a combination of operations of the movable unit 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 comes into contact with or touches a target object to be worked in the middle of an operation pattern realized based on the robot control information. Work is performed in close proximity. FIG. 3 exemplifies two postures of the production robot 40 realized during the operation pattern: a posture indicated by a solid line and a posture indicated by a two-dot chain line.

  For example, when the operation of the production robot 40 is a welding operation, a welding machine is attached to the tip of the production robot 40 as the operation execution unit 250, and the production robot 40 moves the operation execution unit 250 to the welding location before performing the welding. An operation pattern in which the work execution unit 250 is brought into contact with or close to the welding position after the welding is performed is performed. Further, when the operation of the production robot 40 is an operation of assembling parts, a robot hand is attached to the tip of the production robot 40 as an operation execution unit 250, and a part between the parts storage area beside the production robot 40 and the assembly target location. Then, an operation pattern for reciprocating the work execution unit 250 is performed.

  Further, as shown in FIG. 3, the production robot 40 includes a work arm 240 as a movable part. The work arm 240 rotates around the rotation shaft 201 by the braking / driving force output from the braking / driving unit. In the present embodiment, the movable part is described as rotating about the center of the joint as a fulcrum. However, the movable part is not limited to rotation, and may perform linear movement or a movement that draws a locus of a curve. .

  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 unit or the braking / driving unit 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, or may be 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 unit, a sensor that measures the braking / driving force or torque generated by the braking / driving unit, or the like.

  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 data itself (so-called raw data) obtained by the sensor 43, or data obtained by analyzing the data obtained by the sensor 43 by an arithmetic circuit (not shown) or the like. There may be. Further, the operation data of the production robot 40 may include information on the time at which the data was acquired by the sensor 43 (time stamp such as date and time) and information on the motion trajectory of the movable part.

  The data transmitted by the communication circuit 41 to the abnormality determination device 100 may include data such as the type of work performed by the production robot 40, the load amount, the frequency, and the like. When replacement or lubrication oil renewal is performed, maintenance data (maintenance history and information on maintenance locations) indicating that maintenance has been performed may be included.

[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 communicably connected to the communication circuit 50, the storage unit 60, and the notification unit 80.

  The communication circuit 50 is connected to be able to communicate with the communication circuit 41 of the production robot 40 wirelessly or by wire. 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 of work performed by the production robot 40, the load amount, the frequency, and the like, 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 by the processing unit 70 when performing the abnormality determination process. When storing the operation data of the production robot 40, the storage unit 60 may store data such as the type of work performed by the production robot 40, the amount of load, the frequency, and the like. May be stored in association with the maintenance data of the production robot 40.

  In addition, the storage unit 60 stores robot control information for realizing the work performed by the production robot 40. The storage unit 60 may store one piece of robot control information for one operation performed by the production robot 40.

  The storage unit 60 may store a plurality of pieces of robot control information for one work. In this case, in the operation pattern realized by the robot control information, the position of the task execution unit 250 when performing the task matches among the plurality of pieces of robot control information. On the other hand, the plurality of pieces of robot control information realize different operation patterns of the production robot 40, so that the operation of the movable unit in the operation pattern does not always match between the plurality of pieces of robot control information.

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

  The processing unit 70 controls the operation of the production robot 40, and further determines the abnormality of the production robot 40 based on the operation state 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 abnormal alarm based on a command from the processing unit 70 and detects an abnormality by a monitoring person or a maintenance person. Let them 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 (an abnormality determination program) that functions 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 the present embodiment, an example is shown in which a plurality of information processing circuits (71, 73, 75, 77, 79) are realized by software. However, it is also possible to prepare the information processing circuit (71, 73, 75, 77, 79) by preparing dedicated hardware for executing the following information processing. Further, the 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, as a plurality of information processing circuits (71, 73, 75, 77, 79), an operation control unit 71, a drive range detection unit 73, an inspection range setting unit 75, an abnormality diagnosis instruction unit 77, An abnormality determination unit 79 is provided.

  The drive range detection unit 73 operates the movable unit in accordance with 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 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 work arm 240 can rotate around the rotation shaft 201. Have been. In addition, the movable parts are similarly connected to each other at the positions of the rotation shaft 202 and the rotation shaft 203. The production robot 40 shown in FIG. 3 has joints at the positions of the rotation axis 201, the rotation axis 202, and the rotation axis 203.

  In FIG. 3, consider the polar coordinates whose origin is a point through which the rotation axis 201 passes in a plane perpendicular to the rotation axis 201, the angle coordinates of the polar coordinates are coordinates θ, and the counterclockwise direction around the rotation axis 201 is the coordinates θ. The direction is to increase. In the example illustrated in FIG. 3, the working arm 240 operates in a range of coordinates θ that satisfies “α1 ≦ θ ≦ α2” (where α1 <α2).

  Assuming that the position of the work arm 240 is represented by the coordinate θ in the robot control information describing the operation pattern of the production robot 40, for example, “increase the coordinate θ from the value α1 to the value α2” or “ The operation of the work arm 240 is represented by the robot control information "reduce 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 among the movable ranges of the movable unit is the non-drive range. It can be recognized that the boundary between the non-drive ranges is at two positions, a position where “θ = α1” and a 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 in accordance with the operation pattern of the production robot 40 based on the robot control information. However, the present invention is not limited to this method. For example, the drive range detection unit 73 can detect the drive range of the movable unit by monitoring the range in which the movable unit operates using the sensor 43 or the like while the production robot 40 performs work.

  Further, in the above example, the “boundary” between the driving range and the non-driving range is expressed as the position where the variable representing the position of the movable part takes a specific value as described above. However, in the actual operation of the production robot 40, depending on the gear engagement when the braking / driving force is transmitted to the movable part by a 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 slightly fluctuate. 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-described error.

  Further, the driving range, the non-driving range, and the boundary are described using the angular coordinates corresponding to the rotation operation of the movable unit, but the present invention is not limited to this. When the movable part performs a linear motion or a motion that draws a curved locus, the drive range, the non-drive range, and the boundary are similarly described by using coordinates corresponding to the motion. Can be.

  The inspection range setting unit 75 determines the inspection range including the boundary between the driving range and the non-driving range based on the driving range detected by the driving 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 driving range and the non-driving range. The inspection range is set to have a predetermined width centered on the boundary between the drive range and the non-drive range.

  As illustrated in FIG. 4, the inspection range setting unit 75 sets an inspection range R1 indicated by a range of coordinates θ such that “β11 ≦ θ ≦ β12” with respect to a boundary at the position “θ = α1”. With respect to the boundary at the position “θ = α2”, an inspection range R2 indicated by a range of coordinates θ satisfying “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 set inspection range may be set to include only a part of the boundary between the driving range and the non-driving 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 ranges R1 and R2 are set so as to include only a part of the boundary between the driving range and the non-driving range.

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

  Note that 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 driving range. Further, when the braking / driving force is transmitted to the movable portion by the gear, the inspection range is set based on the number of teeth of the gear, and the greater 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 of the production robot 40, the position of the boundary between the drive range and the non-drive range depends on the degree of gear engagement, the processing accuracy of parts, the state of wear of parts, etc. Is considered in order to guarantee that the inspection range is set to include the boundary without fail.

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

  The abnormality diagnosis instructing unit 77 may receive an instruction to start abnormality diagnosis from a monitor or a maintenance person via a user interface or the like (not shown). Alternatively, a command to start operation for abnormality diagnosis may be transmitted to the operation control unit 71. The abnormality diagnosis instructing unit 77 may transmit a command to start an operation for abnormality diagnosis to the operation control unit 71 at the time of a sleep state in which the production robot 40 is not performing work.

  The operation control unit 71 receives a command to start an operation for abnormality diagnosis from the abnormality diagnosis instruction unit 77, and controls the production robot 40 to perform an operation for abnormality diagnosis. More specifically, the operation control section 71 controls the movable section to operate over the set inspection range. While operating the movable part 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 illustrated in FIG. 4, the operation control section 71 “increases the coordinate θ from the value β11 to the value β12” or “changes the coordinate θ” in order to operate the work arm 240 that is a movable portion in the inspection range R1. Is reduced from the value β12 to the value β11 ”. In addition, in order to operate the work arm 240 in the inspection range R2, the operation control unit 71 causes the robot “to increase the coordinate θ from the value β21 to the value β22” or “to decrease the coordinate θ from the value β22 to the value β21”. Send control information.

  When the operation control unit 71 operates the movable unit over the inspection range, the operation control unit 71 may control the movable unit to move at a constant speed or at a constant acceleration.

  According to the example illustrated in FIG. 4, the operation control unit 71 may control the work arm 240 to perform a constant angular velocity movement or a constant angular acceleration movement about the rotation shaft 201 as a fulcrum. That is, control may be performed so that the first-order time derivative or the second-order time derivative of the coordinate θ indicating the position of the work arm 240 is constant.

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

  There are various methods of abnormality determination performed by the abnormality determination unit 79. For example, the abnormality determination unit 79 determines “normal” when a part of the operation data (for example, the acceleration value acquired by the acceleration sensor) is smaller than the threshold, and determines “abnormal” when the value is equal to or larger than the threshold. This threshold value may be estimated and determined in advance from data such as experiments, or may be determined using a statistical test value, Mahalanobis distance, or the like.

  The abnormality determination unit 79 compares the first data in the case where the movable range exists in the drive range and the second data in the case where the movable unit exists in the non-drive range in the operation data, and determines whether the production robot 40 has an abnormality. May be determined. 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 the ratio of the two data is equal to or greater than a threshold.

  Further, the abnormality determination unit 79 compares the first data in the case where there is a movable part in the drive range and the boundary data in the case where there is a movable part at the boundary position among the operation data, The abnormality may be determined. Further, the abnormality determination unit 79 compares the second data in the case where there is a movable part in the non-driving range with the boundary data in the case where there is a movable part at the boundary position in the operation data, and May be determined. As a method of comparing data, a method similar to the method 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 sets the third data when there is a movable part in one inspection range and the third data when there is a movable part in another inspection range. The fourth data may be compared with the fourth data to determine the abnormality of the production robot 40. As a method of comparing data, a method similar to the method 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. However, when the abnormality determining unit 79 determines that the production robot 40 is abnormal, the processing unit 70 may execute an abnormal time process. As the abnormal-time process, for example, an alarm may be issued by the notification unit 80 to notify a monitoring person or a maintenance person that the abnormality has been detected.

  As an abnormal time process, a process of excluding, from the robot control information used to cause the production robot 40 to perform a specific operation, the robot control information in which the movable part may operate at or near the boundary used for the abnormality determination. May be performed. By using the robot control information not excluded by the process at the time of executing the operation of the production robot 40, it is possible to avoid the problem that the movable part does not operate normally. The abnormal state can be prevented from further worsening.

  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. If the work arm 240 is further operated, the abnormal state may be deteriorated. Therefore, instead of the operation pattern in which the work arm 240 operates in the drive range W1 (first operation pattern), the work is performed in an operation pattern in which the work arm 240 does not operate in the drive range W1 (second operation pattern). It is desired to perform. 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. , And instructs the production robot 40.

  Comparing the first operation pattern and the second operation pattern, the position of the operation execution unit 250 when performing the operation in the second operation pattern is the same as the position of the operation execution unit 250 when performing the operation in the first operation pattern. It 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.

[Procedure for abnormality judgment]
Next, an example of a processing procedure of abnormality determination according to the present embodiment will be described with reference to the flowchart of FIG. FIG. 2 is a flowchart showing the operation of the abnormality determination device according to one embodiment of the present invention. The abnormality determination process shown in FIG. 2 is started when an instruction to start abnormality diagnosis is given by a monitor or maintenance person, or at a predetermined timing during a period when the production robot 40 is running.

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

  In step S103, the drive range detection unit 73 detects a 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 in that the movable unit operates in the drive range.

  Further, the drive range detection unit 73 detects the drive range of the movable unit, recognizes the range excluding the drive plate among the movable ranges of the movable unit as the non-drive range, and furthermore, determines 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 driving range and the non-driving 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 instructing unit 77 transmits a command to start operation for abnormality diagnosis to the operation control unit 71. The operation 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 part 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 determining unit 79 determines an abnormality of the production robot 40 based on the operation data obtained 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 abnormal time processing.

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

[Effects of Embodiment]
As described above in detail, 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 unit is set within the movable range. By operating the movable part over the inspection range, the operation data of the machine is acquired, and the abnormality of the machine is determined based on the acquired operation data.

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

  For example, the boundary between the driving range and the non-driving range and the vicinity of the boundary are places where deceleration / acceleration of the gears for operating the joints of the robot arm are likely to occur, and abnormalities and failures such as flaking are likely to occur. In the method of monitoring only the operation of (1), comparison with the operation outside the driving range where flaking is unlikely to occur cannot be performed. 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 movement outside the drive range where flaking is unlikely to occur. A comparison can be made, and a sign of a machine abnormality or failure can be accurately detected.

  In addition, 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 predetermined range width 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 it is difficult to mix the measurement results when the movable part exists in the other range. As a result, the signal can be stably acquired by the sensor, and the abnormality detection performance can be improved. Further, it is possible to perform an abnormality determination specialized for an abnormality or a failure which is likely to occur at the boundary and near the boundary.

  Furthermore, 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 that is approximately 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. Further, it is possible to perform an abnormality determination specialized for an abnormality or a failure which is likely to occur at the boundary and near the boundary.

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

  In the actual operation of the production robot 40, considering that the position of the boundary between the driving range and the non-driving range can vary depending on the degree of meshing of the gears, the larger the number of gear teeth, the more the position of the boundary. The fluctuation range is small. Therefore, when the number of gear teeth 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 diagnosed. Further, the measurement results when the movable portion exists in a range other than the range such as the boundary or the vicinity of the boundary are less likely to be mixed.

  Furthermore, according to the abnormality determination method and the abnormality determination device according to the present embodiment, of the operation data, the first data when the movable portion is in the driving range and the second data when the movable portion is in the non-driving range. May be compared to determine the abnormality of the machine. Since it is difficult to determine anomalies from local data only for data when the movable part is at the boundary position, it is possible to determine anomalies by using global data. Abnormality determination can be performed. 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 abnormality state 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 the movable portion is in one of the plurality of inspection ranges, The abnormality may be determined by comparing the fourth inspection data when there is a movable part in another inspection range among the inspection ranges described above.

  The case where a plurality of inspection ranges can be set corresponds to the case where there are a plurality of boundaries. The load on the movable part may be different for each boundary, and the degree of an abnormal state occurring at the boundary may also be different. By comparing the data for each boundary, the abnormality detection performance can be improved. Further, the tendency of the abnormality can be clarified, and the cause of the abnormality can be easily specified.

  Furthermore, 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 a constant angular velocity or a constant angular acceleration over the inspection range to acquire operation data. It may be something. In this case, since the angular velocity or the angular acceleration of the movable part when the movable part passes through the boundary and the vicinity of the boundary can be kept constant, the signal can be stably acquired by the sensor, and the abnormality detection performance is improved. be able to. Further, noise entering the signal to be obtained can be reduced.

  Further, according to the abnormality determination method and the abnormality determination device according to the present embodiment, when the movable portion linearly moves in the movable range, the movable portion is moved at a constant speed 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 movable portion when the movable portion passes through the boundary and the vicinity of the boundary can be kept constant, a signal can be stably acquired by the sensor, and the abnormality detection performance is improved. Can be. Further, noise entering the signal to be obtained can be reduced.

  Furthermore, 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 at which the operation data was acquired. Since the change of the abnormality can be grasped in chronological order, the change point of the abnormality can be detected, and the abnormality detection performance can be improved.

  In addition, according to the abnormality determination method and the abnormality determination device according to the present embodiment, the operation data may include information on the motion trajectory of the movable unit. Thereby, the abnormality determination can be performed in association with the motion trajectory, so that the abnormality detection performance can be improved. Further, the tendency of the abnormality can be clarified, and the cause of the abnormality can be easily specified.

  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 at least one of the type of work performed by the machine, the load amount, and the frequency. . Since the abnormality determination can be performed in association with the type of work performed by the machine, the load amount, the frequency, and the like, the abnormality detection performance can be improved. Further, the tendency of the abnormality can be clarified, and the cause of the abnormality can be easily specified.

  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 maintenance history or the maintenance location of the machine. Since maintenance data such as a maintenance history or a maintenance location of the machine can be used for abnormality determination, it is possible to generate a probability distribution or the like based on a past abnormality occurrence state, and improve 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 work arm. Further, the machine may include at least one or more joints, and the work arm may be configured to rotate around the center of the joint. Of the movable parts constituting the machine, the abnormality determination is performed only for the work arm, so that the abnormality determination can be performed more efficiently than in the case where a plurality of movable parts are included, and the abnormality detection performance can be improved.

  In addition, according to the abnormality determination method and the abnormality determination device according to the present embodiment, the joint included in the machine is a reduction gear attached to the motor, and the operation data includes at least a gear position of the reduction gear. It may be something. Since information on the gear position can be used for abnormality determination, the position of the boundary 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.

  Furthermore, when it is determined based on the abnormality determination method and the abnormality determination device according to the present embodiment that the machine having the work execution unit operates in the first operation pattern, it is different from the first operation pattern. In the control method and the control device for controlling the machine to operate in the second operation pattern, the position of the operation execution unit when performing the operation in the second operation pattern is determined by the operation execution unit when performing the operation in the first operation pattern. And the second drive range of the movable part determined by the second operation pattern may be different from the first drive range of the movable part determined by the first operation pattern.

  Thus, based on the result of the boundary abnormality detection, the drive range of the movable unit other than the work execution unit is changed without changing the position of the work execution unit, so that the drive range overlaps with the boundary used for abnormality determination or its vicinity. Can be avoided.

  In particular, of the robot control information used when causing the machine to perform work, robot control information that may cause the movable part to 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 movable part does not operate normally.

  Further, it is possible to prevent the boundary where the abnormality has occurred and the abnormal state near the boundary from being further deteriorated. As a result, it is possible to reduce the probability that the target portion of the abnormality determination will break down.

  Each function described in the above embodiment can be implemented by one or a plurality of processing circuits. Processing circuits include programmed processors, electrical circuits, and the like, as well as devices such as application specific integrated circuits (ASICs), and circuit components arranged to perform the described functions. Also included.

  As described above, the contents of the present invention have been described along the embodiments, but the present invention is not limited to these descriptions, and it is obvious to those skilled in the art that various modifications and improvements are possible. The discussion and drawings that form part of this disclosure should not be understood as limiting the invention. From this disclosure, various alternative embodiments, examples, and operation techniques will be apparent to those skilled in the art.

  The present invention naturally includes various embodiments and the like not described herein. Therefore, the technical scope of the present invention is defined only by the matters specifying the invention according to the claims that are appropriate from the above description.

Reference Signs List 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 determination unit 80 notification unit 100 abnormality determination device 201, 202 , 203 Rotation axis 230 Arm support part 240 Work arm 250 Work execution part R1, R2 Inspection range W1, W2 Drive range

Claims (17)

An abnormality determination method for determining an abnormality of the machine, which performs a predetermined operation by operating the movable unit in a predetermined drive range of a movable range of the movable unit included in the machine,
A range excluding the drive range from the movable range as a non-drive range, an inspection range including a boundary between the drive range and the non-drive range is set within the movable range,
Operating the movable section over the inspection range to acquire operation data of the machine,
Determining an abnormality of the machine based on the acquired operation data;
An abnormality determination method characterized by the following. The abnormality determination method according to claim 1, wherein
The method according to claim 1, wherein the inspection range is set to have a width of a predetermined range around the boundary. The abnormality determination method according to claim 2, wherein
The abnormality determination method according to claim 1, wherein the inspection range is set to have a width of about 10% of a width of the driving range. The abnormality determination method according to claim 2, wherein
When the braking / driving force is transmitted to the movable portion by a gear,
The inspection range is set based on the number of teeth of the gear,
An abnormality determination method, wherein the width of the inspection range is set smaller as the number of teeth increases. An abnormality determination method according to any one of claims 1 to 4,
Among the operation data, first data when the movable portion is present in the driving range and second data when the movable portion is present in the non-driving range are compared to determine the abnormality of the machine. Abnormality determination method. An abnormality determination method according to any one of claims 1 to 5,
When a plurality of the inspection ranges can be set,
Third data when the movable portion is present in one inspection range of the plurality of inspection ranges, and when the movable portion is present in another inspection range of the plurality of inspection ranges different from the third data. And determining the abnormality of the machine by comparing the fourth data with the fourth data. An 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, wherein the operation data is acquired by moving the movable section at a constant angular velocity or a constant angular acceleration over the inspection range. An abnormality determination method according to any one of claims 1 to 6,
When the movable part linearly moves in the movable range,
An abnormality determination method, wherein the operation data is acquired by moving the movable part at a constant speed or a constant acceleration over the inspection range. An abnormality determination method according to any one of claims 1 to 8,
An abnormality determination method, wherein the operation data is stored in association with a time at which the operation data was acquired. An abnormality determination method according to any one of claims 1 to 9,
An abnormality determination method, wherein the operation data includes information on an operation trajectory of the movable unit. An abnormality determination method according to any one of claims 1 to 10,
An abnormality determination method, wherein the operation data is stored in association with at least one of a type, a load, and a frequency of the work performed by the machine. An abnormality determination method according to any one of claims 1 to 11,
An abnormality determination method, wherein the operation data is stored in association with a maintenance history or a maintenance location of the machine. An abnormality determination method according to any one of claims 1 to 12,
The method according to claim 1, wherein the movable part is a work arm. The abnormality determination method according to claim 13, wherein
The machine comprises at least one or more joints;
An abnormality determination method, wherein the work arm rotates around a center of the joint. The abnormality determination method according to claim 14,
The joint is a reducer assembled to a motor,
The abnormality determination method, wherein the operation data includes at least a gear position of the speed reducer. A second device different from the first operation pattern when the machine operating in the first operation pattern is determined to be abnormal based on the abnormality determination method according to any one of claims 1 to 15. A control method for controlling the machine to operate in 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, wherein a second drive range of the movable section determined by the second operation pattern is different from a first drive range of the movable section determined by the first operation pattern. An abnormality determination device that determines an abnormality of the machine that performs a predetermined operation by operating the movable unit in a predetermined drive range of a movable range of a movable unit included in the machine,
A controller for controlling the machine,
The controller is
A range excluding the drive range from the movable range as a non-drive range, an inspection range including a boundary between the drive range and the non-drive range is set within the movable range,
Operating the movable section over the inspection range to acquire operation data of the machine,
Determining an abnormality of the machine based on the acquired operation data;
An abnormality determination device characterized by the above-mentioned.

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