robot

Abstract

A robot includes: a robot mechanism section having a plurality of joints and a plurality of drive sections (11-16); a control section (22) that causes the robot mechanism section to perform a prescribed checking operation for checking an arbitrary target drive section (14) among the drive sections (11-16) by controlling the drive sections (11-16); and a notification section (24) that notifies of maintenance information of the target drive section (14) based on a current value of a motor (14a) of the target drive section (14) or information related to the current value in the prescribed checking operation; the prescribed checking operation includes: an operation of approaching and pushing an object at a prescribed position from a prescribed start position by the front end of the robot mechanism section or a tool of the front end; and an operation of separating the front end of the robot mechanism section or the tool from the object by sending a control command for rotating the joint by a prescribed rotation angle to the motor (14a) of the target drive section (14).

Description

Technical Field

[0001] This invention relates to robots. Background Technology

[0002] Currently, gears are used in the drive units of various machines. The backlash of gears may increase with prolonged use of the machine. Therefore, a method for measuring the backlash of gears is proposed. (See, for example, Patent Documents 1-3.)

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 62-140786

[0006] Patent Document 2: Japanese Patent Application Publication No. 2013-249027

[0007] Patent Document 3: Japanese Patent Application Publication No. 2018-073327 Summary of the Invention

[0008] The problem the invention aims to solve

[0009] In the drive unit of an industrial robot arm, gears are used as reducers. Due to increased backlash in the gears, the position of the arm's tip and the tool connected to it becomes unstable. Therefore, it is necessary to systematically maintain the gears before the position of the arm's tip and the tool becomes unstable.

[0010] Solution for solving the problem

[0011] One aspect of the present invention is a robot comprising: a robot mechanism having a plurality of joints and a plurality of drive units that drive the plurality of joints respectively; a control unit that controls the plurality of drive units to cause the robot mechanism to perform a predetermined inspection action for inspecting a target drive unit, the target drive unit being any one of the plurality of drive units having a motor and gears; and a notification unit that notifies maintenance information related to the maintenance of the target drive unit, the maintenance information being maintenance information based on the current value of the motor of the target drive unit or information related to the current value during the predetermined inspection action; the predetermined inspection action includes: sending a control command to the motor of the target drive unit to rotate a target joint by a predetermined rotation angle, the target joint being the joint driven by the target drive unit, thereby pushing the front end of the robot mechanism or a tool connected to the front end toward an object at a predetermined position from a predetermined starting position; and separating the front end of the robot mechanism or the tool from the object. Attached Figure Description

[0012] Figure 1 This is an overall structural diagram of a robot according to one embodiment, and an example of the inspection operation of the drive unit for the fourth joint.

[0013] Figure 2 This is an explanation Figure 1 A diagram illustrating an example of the inspection action of the drive unit used in the fifth joint of a robot.

[0014] Figure 3 This is an explanation Figure 1 A diagram illustrating an example of the inspection action of the drive unit used in the sixth joint of a robot.

[0015] Figure 4 yes Figure 1 Functional block diagram of the robot's control device.

[0016] Figure 5 This is a diagram illustrating the movement of the tool during the inspection process.

[0017] Figure 6 This is a graph showing an example of the time-varying current value of the servo motor of the target drive unit during inspection.

[0018] Figure 7 It is a graph showing the time variation of current values ​​during the inspection operation of servo motors with different backlash amounts for multiple drive units.

[0019] Figure 8 This is a graph showing the relationship between backlash and the maximum current value of the servo motor.

[0020] Figure 9 This describes the situation without using tools. Figure 1 A diagram illustrating an example of a robot's inspection actions.

[0021] Figure 10 This is another example of the inspection action of the drive unit used for the fourth joint.

[0022] Figure 11 This diagram illustrates another example of the inspection action of the drive unit used in the fifth joint.

[0023] Figure 12 This is another example of the inspection action of the drive unit used for the sixth joint.

[0024] Explanation of reference numerals in the attached figures:

[0025] 1: Robotics Mechanism Department

[0026] 10: Robot

[0027] 11, 12, 13, 14, 15, 16: Drive Unit

[0028] 11a, 12a, 13a, 14a, 15a, 16a: Servo motors (motors)

[0029] 11b, 12b, 13b: Reducer

[0030] 14b, 15b, 16b: Reducer (gear)

[0031] 21: Storage Department

[0032] 21a, 21b, 21c: Inspection procedures

[0033] 22: Control Department

[0034] 23: Backlash Calculation Section

[0035] 24: Notification Department

[0036] J1, J2, J3, J4, J5, J6: Joints

[0037] M: Object Detailed Implementation

[0038] The robot 10 of one embodiment of the present invention will be described below with reference to the accompanying drawings.

[0039] like Figures 1 to 3 As shown, the robot 10 includes: a robot mechanism 1; and a control device 2 connected to the robot mechanism 1. Figure 2 and Figure 3 The diagram of control device 2 is omitted.

[0040] Robot mechanism 1 is a six-axis vertical multi-joint robot with six joints J1, J2, J3, J4, J5, and J6. Specifically, robot mechanism 1 includes: a base 3, a rotating body 4, a first arm 5, a second arm 6, and a wrist 7; a tool 8 is mounted on the flange 7a of the wrist 7.

[0041] In addition, the robot mechanism 1 has six drive units 11, 12, 13, 14, 15, and 16 that respectively drive the joints J1, J2, J3, J4, J5, and J6. Drive units 15 and 16 are located inside the second arm 6 and the wrist 7.

[0042] The base 3 is fixed to the ground.

[0043] The rotating body 4 is disposed on the base 3 and connected to the base 3 via the first joint J1. By rotating the first joint J1, the rotating body 4 rotates relative to the base 3 about the first vertical axis A1.

[0044] The first arm 5 is connected to the rotating body 4 via the second joint J2. By rotating the second joint J2, the first arm 5 rotates relative to the rotating body 4 around the horizontal second axis A2.

[0045] The second arm 6 is connected to the front end of the first arm 5 via the third joint J3 and the fourth joint J4. By rotating the third joint J3, the second arm 6 rotates relative to the first arm 5 about a third axis A3 that is parallel to the second axis A2. By rotating the fourth joint J4, the second arm 6 rotates relative to the first arm 5 about a fourth axis A4 that is the major axis of the second arm 6.

[0046] The wrist 7 is connected to the front end of the second arm 6 via the fifth joint J5. By rotating the fifth joint J5, the wrist 7 rotates relative to the second arm 6 about the fifth axis A5, which is orthogonal to the major axis of the second arm 6.

[0047] The flange 7a is supported on the wrist 7 via the sixth joint J6. By rotating the sixth joint J6, the flange 7a rotates relative to the second arm 6 about the sixth axis A6, which is orthogonal to the fifth axis A5.

[0048] like Figure 4 As shown, drive units 11, 12, 13, 14, 15, and 16 respectively have servo motors 11a, 12a, 13a, 14a, 15a, and 16a, and reducers 11b, 12b, 13b, 14b, 15b, and 16b for reducing the rotation of the servo motors 11a, 12a, 13a, 14a, 15a, and 16a.

[0049] Of the three reducers 11b, 12b, and 13b used for the three joints J1, J2, and J3 on the base end side, at least reducer 11b is a precision reducer with little or no backlash, such as an RV reducer (registered trademark). Reducers 12b and 13b may also be precision reducers.

[0050] The reducers 14b, 15b, and 16b used for the three joints J4, J5, and J6 on the front side are gear reducers composed of multiple meshing gears. For example, each reducer 14b, 15b, and 16b includes a hypoid gear composed of meshing input hypoid gears and output hypoid gears. Each output hypoid gear is a gear ring arranged coaxially with the axis A4, A5, or A6 and fixed to the second arm 6, wrist portion 7, or flange portion 7a. Each input gear receives the rotational force of a servo motor 14a, 15a, or 16a.

[0051] Reducers 14b, 15b, and 16b may also include other types of gears that replace hypoid gears and are typically used as reducers.

[0052] like Figure 4As shown, the control device 2 includes: a storage unit 21, a control unit 22, a backlash calculation unit 23, and a notification unit 24.

[0053] The storage unit 21 includes RAM, ROM, and other arbitrary storage devices. The storage unit 21 stores a test program for inspecting the reducer of the target drive unit. The target drive unit is any one of the six drive units 11 to 16 that has gears.

[0054] In this embodiment, the storage unit 21 stores inspection program 21a for reducer 14b, inspection program 21b for reducer 15b, and inspection program 21c for reducer 16b. The target drive unit is selected from the three drive units 14, 15, and 16 equipped with gear reducers 14b, 15b, and 16b.

[0055] The control unit 22 has a processor similar to a CPU. The control unit 22 sends control commands for controlling the servo motors 11a to 16a to the servo motors 11a to 16a, thereby controlling the rotation of joints J1 to J6.

[0056] The control unit 22 controls the servo motors 11a to 16a according to the inspection procedure 21a, thereby causing the robot mechanism unit 1 to perform the prescribed inspection action for inspecting the reducer 14b.

[0057] The control unit 22 controls the servo motors 11a to 16a according to the inspection procedure 21b, thereby causing the robot mechanism unit 1 to perform the prescribed inspection action for inspecting the reducer 15b.

[0058] The control unit 22 controls the servo motors 11a to 16a according to the inspection procedure 21c, thereby causing the robot mechanism unit 1 to perform the prescribed inspection action for inspecting the reducer 16b.

[0059] These prescribed inspection actions are performed regularly, such as once a week, according to the user's instructions or a preset schedule.

[0060] like Figure 5 As shown, the prescribed inspection actions include approaching action, pushing action, and separating action. Arrows S1, S2, and S3 represent the movement of tool 8 during the approaching action, pushing action, and separating action, respectively.

[0061] The inspection operation uses tool 8 and a designated object M positioned around the robot mechanism 1. As described below, during the inspection operation, tool 8 is pushed against object M.

[0062] Tool 8 can be a tool used for holding or processing workpieces, or it can be a tool specifically for checking the operation. In order to check the reducers 14b, 15b, and 16b, tool 8 has a contact point or contact surface that contacts the object M at a position offset from the sixth axis A6 in a direction orthogonal to the sixth axis A6.

[0063] Object M is a sturdy structure, such as a base, that is not deformed or displaced by being pressed by tool 8. Object M is fixed to the ground and positioned in a specified location relative to base 3.

[0064] During the approaching motion, the control unit 22, by actuating the robot mechanism 1, positions the tool 8 at a predetermined passing position P2 on the opposite side of the object M, relative to a predetermined starting position P1. The predetermined starting position P1 is a position where the tool 8 is slightly separated from the object M, and the gap between the object M and the tool 8 at the starting position P1 is, for example, several hundred μm. At this time, the robot mechanism 1 is positioned in an attitude where the tool 8 moves towards the object M from the starting position P1 by rotating the target joint. The target joint is a joint driven by a target drive unit, and in this embodiment, it is any one of joints J4, J5, and J6. Subsequently, the control unit 22, by rotating the target joint, causes the tool 8 to approach from the passing position P2 on the opposite side of the object M towards the starting position P1.

[0065] The result of the approaching action is that, in the initial position P1, the backlash of the meshing gears of the reducers 14b, 15b, or 16b of the target drive unit reaches a predetermined state. That is, the gear teeth are in contact with each other on one side of the gear's rotation direction, and backlash is only formed on the other side of the gear's rotation direction.

[0066] Subsequently, during the pressing action, the control unit 22 sends a control command to the servo motors 14a, 15a, or 16a of the target drive unit to rotate the target joint at a certain speed and a predetermined rotation angle. Thus, the control unit 22 only rotates the target joint, causing the tool 8 to approach the object M from a predetermined starting position P1 and press against the object M. The predetermined rotation angle is, for example, several tens of degrees.

[0067] Figure 6 This illustrates an example of the time-varying current value of the servo motor in the target drive unit during a specified inspection action. After the target joint begins to rotate, tool 8 contacts object M before the target joint's rotation angle reaches the specified rotation angle. After tool 8 contacts object M, as... Figure 6 As shown, in order to overcome the force from object M and move tool 8 further, the current value of the servo motors 14a, 15a or 16a of the target drive unit gradually increases, and the pushing force of tool 8 on object M gradually increases.

[0068] Subsequently, during the separation action, the control unit 22 separates the tool 8 from the object M by reversing the target joint.

[0069] The backlash calculation unit 23 monitors the current value of the servo motors 14a, 15a, or 16a of the target joint during the specified inspection operation. There is a predetermined relationship between the backlash amount and the current value during the specified inspection operation: the larger the backlash amount, the lower the maximum current value. Based on this relationship, the backlash calculation unit 23 calculates the backlash amount of the gears in the reducers 14b, 15b, or 16b of the target drive unit according to the maximum current value.

[0070] Figure 7 The experimental results are shown, demonstrating the measurement of servo motor current values ​​during a specified inspection operation for target drive units with varying backlash in the reducer. Figure 7 In the experiment, the target drive unit is the drive unit used for the fifth joint J5, and the specified rotation angle of the fifth joint J5 under the pushing action is 0.3°. Figure 8 From Figure 7 The graph shows the relationship between the maximum current value of the servo motor and the backlash, derived from the current value chart. Figure 7 and Figure 8 As shown, the larger the backlash, the smaller the maximum current value. This is because a larger backlash results in a longer time interval T (refer to the reference time interval) for increasing the current value. Figure 6 The later it is, the smaller the final pushing force of tool 8 on object M becomes.

[0071] The notification unit 24 notifies the operator of maintenance information based on the backlash amount calculated by the backlash calculation unit 23. The maintenance information concerns the maintenance of the target drive unit. For example, the notification unit 24 displays the maintenance information on the display screen (not shown) of the control device 2, or outputs an audio message based on the content of the maintenance information from the control device 2.

[0072] For example, when the backlash exceeds a specified threshold, the notification unit 24 sends a maintenance message indicating the time to replace the reducer in the target drive unit.

[0073] When the backlash is below a predetermined threshold, the notification unit 24 predicts the replacement time of the reducer of the target drive unit and notifies the maintenance unit of the predicted replacement time. For example, the notification unit 24 calculates the rate of increase of the backlash using the operating time of the robot mechanism 1 and the current backlash. Assuming that the backlash increases at the calculated rate of increase, it calculates the remaining operating time until the backlash reaches the predetermined threshold and predicts the replacement time from the remaining operating time.

[0074] When the backlash increases sharply, the notification unit 24 sends out maintenance information indicating a sharp increase in backlash. A sharp increase in backlash may be caused by, for example, a collision with an external object of the robot mechanism 1. Whether the backlash has increased sharply is determined, for example, by whether the difference between the previously measured backlash and the current measured backlash is above a specified amount.

[0075] Next, the function of robot 10 will be explained.

[0076] The control unit 22 causes the robot mechanism unit 1 to sequentially execute the inspection actions of the reducers 14b, 15b, and 16b of the target drive units 14, 15, and 16 according to the inspection procedures 21a, 21b, and 21c.

[0077] During the inspection operation of reducer 14b, control unit 22 controls servo motors 11a-16a to move robot mechanism 1, positioning tool 8 at via position P2. Then, by controlling servo motor 14a to rotate fourth joint J4, tool 8 approaches starting position P1 from via position P2. Afterwards, control unit 22 sends a command to servo motor 14a to rotate at a predetermined angle, causing only fourth joint J4 to rotate, thus moving tool 8 from starting position P1 towards object M and pressing against it. Then, control unit 22 controls servo motor 14a to rotate fourth joint J4 in the opposite direction, separating tool 8 from object M.

[0078] During the aforementioned inspection process, the backlash calculation unit 23 monitors the current value of the servo motor 14a and detects the maximum value of the current. Then, the backlash calculation unit 23 calculates the backlash of the gear in the reducer 14b based on the maximum current value.

[0079] Afterwards, the maintenance information regarding the backlash of the gears in the reducer 14b is communicated to the operators via the notification unit 24.

[0080] After the inspection of reducer 14b, the inspection of reducers 15b and 16b is performed similarly, and maintenance information based on the backlash of the gears in reducers 15b and 16b is communicated to the operators.

[0081] Based on the maintenance information provided by the notification department 24, operators are able to plan preventative maintenance for reducers 14b, 15b, and 16b.

[0082] For example, when maintenance information indicating the replacement time of reducer 14b is notified, the operator recognizes that the backlash of reducer 14b has increased above the specified threshold and replaces reducer 14b with a new reducer before the position of tool 8 becomes unstable. When maintenance information indicating the predicted replacement time of reducer 14b is notified, the operator creates a schedule up to the replacement time for reducer 14b. When maintenance information indicating a sharp increase in backlash is notified, the operator recognizes that the backlash of reducer 14b has increased sharply for some reason and replaces reducer 14b with a new reducer as needed.

[0083] Thus, according to this embodiment, inspection operations of the reducers 14b, 15b, and 16b of the drive units 14, 15, and 16 are performed periodically. During the inspection operations, the backlash of the gears in the reducers 14b, 15b, and 16b is measured, and maintenance information based on the backlash is communicated by the notification unit 24. Based on the maintenance information, the operator can identify the maintenance required for each reducer 14b, 15b, and 16b, and can plan preventative maintenance for the reducers 14b, 15b, and 16b before the front end of the robot mechanism unit 1 and the position of the tool 8 become unstable.

[0084] Furthermore, according to this embodiment, by having the robot mechanism 1 perform a prescribed inspection action, the backlash can be measured based on the current values ​​of the servo motors 14a, 15a, and 16a during the inspection action without the use of any special device.

[0085] Furthermore, according to this embodiment, by pre-preparing the inspection procedures 21a, 21b, and 21c in the storage unit 21, the robot mechanism unit 1 can perform the inspection actions of the reducers 14b, 15b, and 16b without the need for operators to write programs.

[0086] When gears are used in multiple drive units, the backlash of the gear in the target drive unit calculated by the backlash calculation unit 23 is affected by the backlash of the gears in other drive units. Therefore, the control unit 22 preferably causes the robot mechanism 1 to perform the above-mentioned inspection operation in an inspection posture configuration where the backlash of the gear in the target drive unit is unlikely to be affected by the backlash of the gears in other drive units besides the target drive unit.

[0087] Figure 1 , Figure 2 and Figure 3 Examples of the inspection postures of robot mechanism 1 during the inspection actions of reducers 14b, 15b and 16b are shown respectively.

[0088] Furthermore, as mentioned earlier, among the three reducers 11b, 12b, and 13b on the base end side, at least reducer 11b is a precision reducer with little or no backlash. Therefore, the measurement of the backlash of reducers 14b, 15b, and 16b is not affected by the backlash of reducer 11b.

[0089] exist Figure 1 , Figure 2 and Figure 3 In the inspection posture, the first arm 5 is positioned such that the gravitational torque caused by the gravity acting on the first arm 5 acts on the second joint J2, and the second arm 6 is positioned such that the gravitational torque acting on the second arm 6 acts on the third joint J3. In this posture, in the reducer 12b used for the second joint J2, the gear teeth are in contact with each other on one side of the gear's rotation direction, and backlash is formed only on the other side of the gear's rotation direction. Similarly, utilizing the gravity acting on the second arm 6, in the reducer 13b used for the third joint J3, the gear teeth are in contact with each other on one side of the gear's rotation direction, and backlash is formed only on the other side of the gear's rotation direction. Therefore, the backlash of the gears in the reducers 12b and 13b is not affected, and the target joints J4, J5, or J6 can be rotated during the inspection operation.

[0090] In addition, Figure 1 , Figure 2 and Figure 3 In the inspection posture, among the three joints J4, J5, and J6 on the front side, the axis of the target joint is positioned vertically, while the axes of the other two joints are parallel to a direction orthogonal to the axis of the target joint. Specifically, in Figure 1 In the diagram, the fourth axis A4 is positioned vertically, while the fifth axis A5 and the sixth axis A6 are parallel to directions orthogonal to the fourth axis A4. Figure 2 In the diagram, the fifth axis A5 is positioned vertically, while the fourth axis A4 and the sixth axis A6 are parallel to directions orthogonal to the fifth axis A5. Figure 3 In this configuration, the sixth axis A6 is positioned vertically, while the fourth axis A4 and the fifth axis A5 are parallel to directions orthogonal to the sixth axis A6. In this orientation, the direction of tool 8 movement caused by the rotation of the other two joints is orthogonal to the direction of tool 8 movement caused by the rotation of the target joint. Therefore, it is not affected by the backlash of the gears in the reducers of the other two joints, and the target joint can be rotated during the inspection operation.

[0091] In the above embodiment, the backlash amount calculated by the backlash calculation unit 23 can also be stored in the storage unit 21 in a time sequence.

[0092] According to this configuration, time-series data of the backlash amount of each reducer 14b, 15b, and 16b is generated in the storage unit 21. The time-series data of the backlash amount is effective for preventive maintenance of reducers 14b, 15b, and 16b.

[0093] For example, during an assembly operation where a workpiece held by tool 8 is attached to a part, a malfunction may occur where the workpiece suddenly fails to attach to the part. One cause of this malfunction is a sharp increase in the backlash of reducers 14b, 15b, or 16b. By referring to the time-series data of the backlash stored in storage unit 21 and confirming whether the backlash of reducers 14b, 15b, or 16b has increased sharply, the operator can determine whether the cause of the malfunction lies in reducers 14b, 15b, or 16b.

[0094] In the above embodiment, during the inspection action, tool 8 pushes object M instead, as shown in the example. Figure 9 As shown, the object M can also be pushed by the wrist 7 at the front end of the robot mechanism 1.

[0095] Thus, by directly pressing the object M with the wrist 7, just as with the case where the tool 8 presses the object M, the backlash can be calculated based on the maximum value of the current of the servo motors 14a, 15a, and 16a.

[0096] In the above embodiment, the notification unit 24 determines the content of the maintenance information to be notified to the operator based on the backlash amount calculated by the backlash calculation unit 23. Alternatively, it can determine the content of the maintenance information to be notified to the operator based on the maximum value of the current of the servo motors 14a, 15a or 16a during the specified inspection operation.

[0097] For example, the notification unit 24 can also monitor the current value of the servo motors 14a, 15a or 16a of the target joint during the specified inspection action, detect the maximum value of the current value, and notify maintenance information based on the maximum value.

[0098] In this case, the backlash calculation unit 23 does not necessarily have to be installed on the robot 10.

[0099] In the above embodiment, the specified object is a structure M disposed around the robot mechanism 1. Alternatively, the specified object may also be a part of the robot mechanism 1.

[0100] According to this configuration, even if there are no suitable structures for inspection actions around the robot structure 1, inspection actions can still be performed.

[0101] Figure 10 , Figure 11 and Figure 12Examples of the inspection actions of reducers 14b, 15b, and 16b are shown respectively, when a portion of robot mechanism 1 is used as a specified object. Figure 10 , Figure 11 and Figure 12 In the middle, the robot mechanism 1 is configured in the posture for inspection.

[0102] From Figures 10 to 12 In the inspection action shown, tool 8 is pressed against the base end of the second arm 6. A robust component 5a may be provided on the base end of the second arm 6, which provides a surface for pressing tool 8.

[0103] In the above embodiment, the backlash amount calculated by the backlash calculation unit 23 is used for preventive maintenance of gear reducers 14b, 15b, and 16b. Alternatively, it can be used for position correction of tool 8 as a substitute or supplement.

[0104] The larger the backlash of reducers 14b, 15b, and 16b, the greater the positional error of tool 8. Control unit 22 can also calculate a correction value based on the backlash and send a control command that corrects the position using the calculated correction value to the servo motor.

[0105] In the above embodiment, the tooth backlash calculation unit 23 calculates the tooth backlash based on the current value. Alternatively, it may calculate based on other information related to the current value.

[0106] For example, the backlash calculation unit 23 can also calculate the backlash amount based on the interference value. The interference value is the difference between the commanded value of the input current of the servo motor and the measured value of the current. Since there is a correlation between the backlash amount and the interference value, the backlash can be calculated based on the interference value.

[0107] In the above embodiment, the robot mechanism 1 is a six-axis vertical joint robot. Alternatively, the robot mechanism 1 can also be other types of industrial robots. For example, the robot mechanism 1 can also be a vertical joint robot with other axes, a parallel robot, etc.

Claims

1. A robot, characterized in that, have: The robot mechanism has multiple joints and multiple drive units that drive the multiple joints respectively; The control unit controls the plurality of drive units to cause the robot mechanism to perform a predetermined inspection action for inspecting the target drive unit, wherein the target drive unit is any one of the plurality of drive units that has a motor and gears. The notification department notifies maintenance information related to the maintenance of the target drive unit, the maintenance information being maintenance information based on the current value of the motor of the target drive unit or information related to the current value during the prescribed inspection operation; as well as Backlash calculation unit, The prescribed inspection actions include: By sending a control command to the motor of the target drive unit to rotate the target joint by a predetermined rotation angle, the target joint being the joint driven by the target drive unit, thereby pushing the front end of the robot mechanism or the tool connected to the front end from a predetermined starting position toward an object at a predetermined position. as well as The action of separating the front end or the tool of the robot mechanism from the object. The backlash calculation unit monitors the current value of the motor of the target drive unit, detects the maximum value of the current value of the motor of the target drive unit during the period when the target joint rotates by the predetermined rotation angle, and calculates the backlash of the gear of the target drive unit based on the detected maximum value.

2. The robot according to claim 1, characterized in that, The notification unit notifies the maintenance information based on the backlash amount calculated by the backlash calculation unit.

3. The robot according to claim 1, characterized in that, The robot mechanism is a six-axis vertical multi-joint robot.

4. The robot according to claim 3, characterized in that, The target drive unit is selected from three drive units that drive the three front joints of the six joints of the six-axis vertical multi-joint robot.

5. The robot according to claim 4, characterized in that, The control unit configures the robot mechanism in an inspection posture during the prescribed inspection operation, so that it is less affected by the backlash of other drive units besides the target drive unit.

6. The robot according to claim 5, characterized in that, In the posture used for inspection. The axis of the target joint is configured in the vertical direction; The axes of the two joints other than the target joint among the three joints are parallel to a direction orthogonal to the axis of the target joint.

7. The robot according to any one of claims 1 to 6, characterized in that, The prescribed inspection action includes: rotating the target joint to cause the front end of the robot mechanism or the tool to approach the prescribed starting position from the opposite side of the object.

8. The robot according to any one of claims 1 to 6, characterized in that, The robot has the following features: The storage unit stores the backlash amount calculated by the backlash calculation unit in time sequence.

9. The robot according to any one of claims 1 to 6, characterized in that, The object is part of the robot mechanism.

10. The robot according to any one of claims 1 to 6, characterized in that, The robot has the following features: Storage department, its storage check procedures; The control unit controls the plurality of drive units according to the inspection procedure, causing the robot mechanism to perform the prescribed inspection actions.

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