Robot system

Abstract

The invention provides a robot system which can detect which joint vibrates and can control effective vibration. A robot system includes: a robot including a robot arm including a plurality of arms and a plurality of joints including a base-end-side joint having mutually parallel rotation axes and a tip-end-side joint located on the tip-end side of the base-end-side joint; and an inertial sensor disposed on the arm connecting the distal end-side joint and the joint located on the distal end side prior to the distal end-side joint. The inertial sensor detects an angular velocity about an axis parallel to the rotation axis and an acceleration in a direction orthogonal to the center axis of the arm on which the inertial sensor is disposed and orthogonal to the rotation axis.

Description

Technical Field

[0001] The present invention relates to a robot system. Background Art

[0002] The manipulator described in Patent Document 1 has: an arm having a plurality of joints; an actuator disposed at each joint; an end effector connected to the front end of the arm; and an acceleration sensor disposed at the end effector. In the manipulator configured as described above, the vibration of the end effector is detected by the acceleration sensor, and the vibration is controlled based on the detection result.

[0003] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2022-177607

[0004] However, in the manipulator of Patent Document 1, it is impossible to determine which joint among the plurality of joints of the arm causes the vibration of the end effector. Therefore, it is difficult to control the effective vibration. Summary of the Invention

[0005] The robot system of the present invention includes:

[0006] a robot including a robotic arm, the robotic arm including a plurality of arms and a plurality of joints, the plurality of joints including a base end side joint having rotation axes parallel to each other and a front end side joint located on the front end side of the base end side joint; and

[0007] an inertial sensor disposed on the arm connecting the front end side joint and the joint located on the front end side of the front end side joint,

[0008] the inertial sensor detects an angular velocity about an axis parallel to the rotation axis and an acceleration in a direction orthogonal to the central axis of the arm on which the inertial sensor is disposed and orthogonal to the rotation axis.

[0009] The robot system of the present invention includes:

[0010] a robot including a robotic arm, the robotic arm including a plurality of arms and a plurality of joints, the plurality of joints including a base end side joint having rotation axes parallel to each other and a front end side joint located on the front end side of the base end side joint; and

[0011] an inertial sensor disposed on the arm connecting the joint located on the front end side of the front end side joint and the joint located on the front end side before the front end side joint,

[0012] the inertial sensor detects an angular velocity about an axis parallel to the rotation axis and an acceleration in a direction orthogonal to the central axis of the arm on which the inertial sensor is disposed and orthogonal to the rotation axis.

[0013] The robot system of the present invention includes:

[0014] A robot, having a robotic arm, the robotic arm including a plurality of arms and a plurality of joints, the plurality of joints including a base-end side joint having rotation axes parallel to each other and a front-end side joint located on the front-end side of the base-end side joint; and

[0015] An inertial sensor, disposed on the arm between the front-end side joint and the joint located on the foremost end side,

[0016] The inertial sensor detects an angular velocity about an axis parallel to the rotation axis and an acceleration in a direction orthogonal to the central axis of the arm on which the inertial sensor is disposed and orthogonal to the rotation axis. Description of the Drawings

[0017] Figure 1 is an overall view of the robot system according to the first embodiment.

[0018] Figure 2 is a schematic view showing a posture in which the vibration amounts of the second and third joints cannot be detected only based on acceleration.

[0019] Figure 3 is a schematic view showing a posture in which the vibration amounts of the second and third joints cannot be detected only based on angular velocity.

[0020] Figure 4 is a flowchart showing the control process of the robot.

[0021] Figure 5 is a schematic view for explaining a method for detecting the vibration amount of each of the second and third joints.

[0022] Figure 6 is a schematic view for explaining a method for detecting the vibration amount of each of the second and third joints.

[0023] Figure 7 is a schematic view for explaining a method for detecting the vibration amount of each of the second and third joints.

[0024] Figure 8 is a schematic view for explaining a method for detecting the vibration amount of each of the second and third joints.

[0025] Figure 9 is a schematic view for explaining a method for detecting the vibration amount of each of the second and third joints.

[0026] Figure 10 is a schematic view for explaining a method for detecting the vibration amount of each of the second and third joints.

[0027] Figure 11It is a block diagram showing the configuration of the control unit included in the control device.

[0028] Figure 12 It is a diagram showing an example of the arrangement of the inertial sensors.

[0029] Figure 13 It is a diagram showing an example of the arrangement of the inertial sensors.

[0030] Figure 14 It is a diagram showing an example of the arrangement of the inertial sensors.

[0031] Figure 15 It is a diagram showing an example of the arrangement of the inertial sensors.

[0032] Figure 16 It is a schematic diagram showing the robot according to the second embodiment.

[0033] Figure 17 It is a diagram showing the arrangement of the inertial sensors.

[0034] Figure 18 It is a schematic diagram showing the robot according to the third embodiment.

[0035] Figure 19 It is a schematic diagram showing the robot according to the fourth embodiment.

[0036] Figure 20 It is a schematic diagram showing the robot according to the fifth embodiment.

[0037] Figure 21 It is a diagram showing the robot according to the sixth embodiment.

[0038] Explanation of reference numerals

[0039] 1: Robot system; 2: Robot; 21: Base; 22: Robot arm; 221: First arm; 222: Second arm; 223: Third arm; 223a: Frame; 223b: Cover; 223c: Inner wall; 223d: Outer wall; 223e: Hollow part; 224: Fourth arm; 225: Fifth arm; 226: Sixth arm; 227: Seventh arm; 231: First joint; 232: Second joint; 233: Third joint; 234: Fourth joint; 235: Fifth joint; 236: Sixth joint; 237: Seventh joint; 24: End effector; 3: Inertial sensor; 31a: Angular velocity detection element; 31b: Angular velocity detection element; 31c: Angular velocity detection element; 31d: Angular velocity detection element; 32a: Acceleration detection element; 32b: Acceleration detection element; 4: Control device; 40: Control unit; 41: Position command generation unit; 42: Position control unit; 43: Speed control unit; 44: Current control unit; 45: Vibration feedback generation unit; 5: Robot; 51: Base; 52: Robot arm; 521: First arm; 522: Second arm; 53: Working head; 531: Spline nut; 532: Ball screw nut; 533: Spline shaft; 533a: Assembly part; 541: First joint; 542: Second joint; 901: Position command; 902: Motor shaft position; 903: Position deviation; 904: Speed command; 905: Speed loop command; 906: Current command; 907: Current; 912: Motor shaft converted arm angular velocity; 913: Motor shaft angular velocity; 914: Vibration angular velocity; 915: Vibration feedback; A: Central axis; Axs: Acceleration; Azs: Acceleration; E: Encoder; J1: First rotation axis; J2: Second rotation axis; J3: Third rotation axis; J4: Fourth rotation axis; J5: Fifth rotation axis; J6: Sixth rotation axis; J7: Seventh rotation axis; J11: First rotation axis; J12: Second rotation axis; J13: Third rotation axis; Kgp: Feedback gain; Kgs: Arm angular velocity scale factor; Kpp: Position loop proportional gain; Kvi: Speed loop integral gain; Kvp: Speed loop proportional gain; L2: Spacing distance; L3: Spacing distance; M: Motor; S1: Inertial information acquisition step; S2: Vibration detection step; S3: Drive control step; Vxs: Translation speed; Vzs: Translation speed; ω: Angular velocity; ω2: Angular velocity; ω3: Angular velocity; ωs: Angular velocity. Detailed implementation mode

[0040] Next, based on the implementation mode shown in the drawings, the robot system of the present invention will be described in detail.

[0041] First implementation mode

[0042] Figure 1 is an overall view of the robot system according to the first implementation mode.Figure 2 It is a schematic diagram showing a posture in which the vibration amounts of the second and third joints cannot be detected only based on acceleration. Figure 3 It is a schematic diagram showing a posture in which the vibration amounts of the second and third joints cannot be detected only based on angular velocity. Figure 4 It is a flowchart showing the control process of the robot. Figures 5 to 10 They are schematic diagrams for explaining the detection methods of the vibration amounts of the second and third joints respectively. Figure 11 It is a block diagram showing the configuration of the control unit included in the control device. Figures 12 to 15 They are diagrams showing examples of the configurations of the inertial sensors respectively.

[0043] Figure 1 The shown robot system 1 includes: a robot 2, an inertial sensor 3 disposed on the robot 2, and a control device 4 that controls the driving of the robot 2.

[0044] The robot 2 is a six-axis vertical articulated robot having six drive axes, and includes a base 21 and a robotic arm 22. The robotic arm 22 is rotatably connected to the base 21. The robotic arm 22 is configured such that the first, second, third, fourth, fifth, and sixth arms 221, 222, 223, 224, 225, and 226 are connected via the first, second, third, fourth, fifth, and sixth joints 231, 232, 233, 234, 235, and 236. Here, the joint on the front end side before the first joint 231 is the second joint 232, the joint on the front end side before the second joint 232 is the third joint 233, the joint on the front end side before the third joint 233 is the fourth joint 234, the joint on the front end side before the fourth joint 234 is the fifth joint 235, and the joint on the front end side before the fifth joint 235 is the sixth joint 236.

[0045] The first arm 221 is connected to the base 21 via the first joint 231 so as to be rotatable about the first rotation axis J1. Further, the second arm 222 is connected to the first arm 221 via the second joint 232 so as to be rotatable about the second rotation axis J2. Further, the third arm 223 is connected to the second arm 222 via the third joint 233 so as to be rotatable about the third rotation axis J3. Further, the fourth arm 224 is connected to the third arm 223 via the fourth joint 234 so as to be rotatable about the fourth rotation axis J4. Further, the fifth arm 225 is connected to the fourth arm 224 via the fifth joint 235 so as to be rotatable about the fifth rotation axis J5. Further, the sixth arm 226 is connected to the fifth arm 225 via the sixth joint 236 so as to be rotatable about the sixth rotation axis J6.

[0046] In addition, among the joints 231, 232, 233, 234, 235, 236, the second, third, and fifth joints 232, 233, 235 are respectively bending joints, and the first, fourth, and sixth joints 231, 234, 236 are respectively twisting joints. In addition, the second rotation axis J2 is orthogonal to the first rotation axis J1, the third rotation axis J3 is parallel to the second rotation axis J2, the fourth rotation axis J4 is orthogonal to the third rotation axis J3, the fifth rotation axis J5 is orthogonal to the fourth rotation axis J4, and the sixth rotation axis J6 is orthogonal to the fifth rotation axis J5. In addition, the second, third, and fifth rotation axes J2, J3, J5 are respectively oriented in the horizontal direction.

[0047] It should be noted that in the description of this application, "parallel" not only refers to the case where the axes are parallel to each other, but also includes the meaning of a deviation that can be regarded as parallel from the perspective of common technical knowledge with respect to parallelism, for example, a deviation that may be caused by the dimensional accuracy, assembly accuracy, etc. of the robot 2. In addition, "orthogonal" not only refers to the case where the axes are orthogonal to each other, but also includes the meaning of a deviation that can be regarded as orthogonal from the perspective of common technical knowledge with respect to orthogonality, for example, a deviation that may be caused by the dimensional accuracy, assembly accuracy, etc. of the robot 2.

[0048] In such a robot 2, the second joint 232 is the "base-end side joint" of this application, and the third joint 233 is the "front-end side joint" of this application.

[0049] In addition, each of the joints 231, 232, 233, 234, 235, 236 has: a motor M; a speed reducer (not shown) that reduces the rotational speed of the motor M and outputs it; and an encoder E that detects the rotational amount of the motor M. The control device 4 drives the motor M through servo control that feeds back the output of the encoder E to control the rotational amount of each of the joints 231, 232, 233, 234, 235, 236.

[0050] In addition, an end effector 24 is assembled at the front end of the robotic arm 22, that is, the sixth arm 226. The end effector 24 is detachable from and attachable to the sixth arm 226 and can be appropriately assembled according to the operation content performed by the robot 2.

[0051] In addition, as Figure 1As shown, the inertial sensor 3 is disposed on the third arm 223. The inertial sensor 3 includes: an angular velocity detection element 31a that detects the angular velocity ωs about an axis having the same orientation as the second and third rotation axes J2 and J3; and an acceleration detection element 32a that detects the acceleration Azs in a direction orthogonal to the central axis A of the third arm 223 and orthogonal to the second and third rotation axes J2 and J3. Specifically, the acceleration Azs is a vertical acceleration generated by the turning motion of the third arm 223 caused by the driving of at least one of the second and third joints 232 and 232. By disposing the inertial sensor 3 on the third arm 223, the detection axis of the angular velocity detection element 31a can be maintained in a state parallel to the second and third rotation axes J2 and J3, and the detection axis of the acceleration detection element 32a can be maintained in a state orthogonal to the second and third rotation axes J2 and J3 at any posture, so that the angular velocity ωs and the acceleration Azs can be detected more reliably.

[0052] As described above, since the inertial sensor 3 is disposed on the third arm 223, it can be said that the inertial sensor 3 is disposed on the arm between the third joint 233, which is the front-end side joint, and the sixth joint 236, which is on the most front-end side. In other words, it can be said that the inertial sensor 3 is not disposed on the sixth arm 226. In this way, by disposing the inertial sensor 3 to avoid the arm at the most front end, the number of joints between the inertial sensor 3 and the third joint 233 can be suppressed to be as small as possible. Therefore, it is not affected by the posture of the robotic arm 22, and it is easy to detect the angular velocity ωs and the acceleration Azs.

[0053] In the present embodiment, as the inertial sensor 3, a sensor unit including the angular velocity detection element 31a and the acceleration detection element 32a is used, but it is not limited thereto, and it may be configured such that an angular velocity sensor including the angular velocity detection element 31a and an acceleration sensor including the acceleration detection element 32a are separately disposed.

[0054] The control device 4 controls the driving of the robot 2. The control device 4 is constituted by a computer, for example, and includes: a processor (CPU) that processes information, a memory connected to the processor in a communicable manner, and an external interface that makes a connection with an external device. Various programs that can be executed by the processor are stored in the memory, and the processor can read and execute the programs stored in the memory and the like.

[0055] Above, the configuration of the robot system 1 has been described. For example, as Figure 2 shown, when the inertial sensor 3 can only detect the acceleration Azs, the angular velocity ω2 based on the vibration of the second joint 232 and the angular velocity ω3 based on the vibration of the third joint 233 cannot be distinguished when the second and third arms 222 and 223 extend together in the horizontal direction. In addition, for example, as Figure 3As shown, when the inertial sensor 3 can only detect the angular velocity ωs, in the posture where the second arm 222 faces the vertical direction and the third arm 223 faces the horizontal direction and they are orthogonal, it is impossible to distinguish the angular velocity ω2 based on the vibration of the second joint 232 from the angular velocity ω3 based on the vibration of the third joint 233. In response to this, in the robot system 1, the inertial sensor 3 can detect the angular velocity ωs and the acceleration Azs, and can distinguish the vibration of the second joint 232 from the vibration of the third joint 233 based on the relationship between the angular velocity ωs and the acceleration Azs. Hereinafter, this method will be described.

[0056] As Figure 4 shown, the control method of the robot 2 includes: an inertial information acquisition step S1 of acquiring the angular velocity ωs and the acceleration Azs from the inertial sensor 3; a vibration detection step S2 of detecting the vibration amounts of the respective joints of the second joint 232 and the third joint 233 based on the angular velocity ωs and the acceleration Azs acquired in the inertial information acquisition step S1; and a drive control step S3 of controlling the vibration based on the detection results of the vibration detection step S2 and based on the vibration amounts of the respective joints. Hereinafter, these steps S1 to S3 will be described in detail.

[0057] Inertial information acquisition step S1

[0058] In the inertial information acquisition step S1, the control device 4 acquires the angular velocity ωs and the acceleration Azs from the inertial sensor 3.

[0059] Vibration detection step S2

[0060] In the vibration detection step S2, the control device 4 detects the vibration amounts of the respective joints of the second joint 232 and the third joint 233 based on the angular velocity ωs and the acceleration Azs acquired in the inertial information acquisition step S1.

[0061] As an example, as Figure 5 shown, the detection method for the second arm 222 and the third arm 223 in the posture of extending straight in the horizontal direction will be described. It should be noted that, as described above, in this posture, the vibration amounts of the respective joints of the second joint 232 and the third joint 233 cannot be detected only based on the acceleration Azs. In addition, as shown in the figure, the distance between the second rotation axis J2 and the third rotation axis J3 is set to L2, and the distance between the third rotation axis J3 and the inertial sensor 3 is set to L3. In Figure 5 this case, the vertical translation speed Vzs of the inertial sensor 3 can be expressed as Vzs = L×ω. The translation speed Vzs is calculated by integrating the acceleration Azs detected by the inertial sensor 3. In addition, L is the distance between the rotation axis of the joint generating the vibration and the inertial sensor 3, and ω is the angular velocity of the joint generating the vibration around the rotation axis.

[0062] As Figure 6 shown, when the second joint 232 vibrates at an angular velocity ω2, then Vzs = (L2 + L3) × ω2, ω = ω2. On the other hand, as Figure 7 shown, when the third joint 233 vibrates at an angular velocity ω3, then Vzs = L3 × ω3, ω = ω3. Thus, when the second joint 232 vibrates and when the third joint 233 vibrates, the relationship between the translational velocity Vzs and the angular velocity ω is different. Specifically, Vzs / ω when the second joint 232 vibrates is greater than Vzs / ω when the third joint 233 vibrates. Therefore, based on the relationship between the translational velocity Vzs and the angular velocity ω, it is possible to determine the vibration amounts of the respective joints of the second joint 232 and the third joint 233.

[0063] Based on the above relationship, the following equations (1) and (2) using the Jacobian matrix hold. Therefore, it is possible to obtain the angular velocities ω2 and ω3 based on L2, L3 measured in advance, the angular velocity ωs detected by the inertial sensor 3, and the translational velocity Vzs calculated from the acceleration Azs detected by the inertial sensor 3. In addition, based on the obtained values of the angular velocities ω2 and ω3, it is possible to determine the vibration amounts of the respective joints of the second joint 232 and the third joint 233.

[0064] [Equation 1]

[0065]

[0066] [Equation 2]

[0067]

[0068] In addition, as another example, as Figure 8 shown, a posture is described in which the second arm 222 is oriented in the vertical direction and the third arm 223 is oriented in the horizontal direction and the second and third arms 222, 223 are orthogonal. At this time, the vertical interval distance from the center of the third arm 222 to the detection center of the acceleration detected by the inertial sensor 3 is set as Lsz. It should be noted that, as described above, in this posture, it is not possible to detect the vibration amounts of the respective joints of the second joint 232 and the third joint 233 only based on the angular velocity ωs.

[0069] As Figure 9 shown, when the second joint 232 vibrates at an angular velocity ω2, Vzs = L3 × ω2, ω = ω2. On the other hand, as Figure 10 shown, when the third joint 233 vibrates at an angular velocity ω3, Vzs = √(L3 2 + Lsz 2)(×ω3, ω = ω3. In this way, when the second joint 232 vibrates and when the third joint 233 vibrates, there will be a difference in the relationship between the translational velocity Vzs and the angular velocity ω. Therefore, based on the relationship between the translational velocity Vzs and the angular velocity ω, it is possible to determine the vibration amounts of the respective joints of the second joint 232 and the third joint 233.)

[0070] According to the above relationship, the following equations (3) and (4) using the Jacobian matrix hold. Therefore, it is possible to obtain the angular velocities ω2 and ω3 based on L2, L3, Lsz measured in advance, the angular velocity ωs detected by the inertial sensor 3, and the translational velocity Vzs calculated from the acceleration Azs detected by the inertial sensor 3. In addition, based on the obtained values of the angular velocities ω2 and ω3, it is possible to determine the vibration amounts of the respective joints of the second joint 232 and the third joint 233.)

[0071] [Equation 3]

[0072]

[0073] [Equation 4]

[0074]

[0075] In the above text, two representative postures in which the vibration amounts of the respective joints of the second joint 232 and the third joint 233 cannot be determined only from either the angular velocity ωs or the acceleration Azs have been described. Of course, in other postures, it is also possible to determine the vibration amounts of the respective joints of the second joint 232 and the third joint 233 based on the relationship between the angular velocity ωs and the acceleration Azs.)

[0076] In the robot 2, in any posture, the following equations (5) and (6) using the Jacobian matrix J also hold. It should be noted that the Jacobian matrix J shows the position of the inertial sensor 3 and is a value that varies according to the rotation amounts of the second and third joints 232 and 233. The position of the inertial sensor 3 is detected based on the outputs of the encoders E provided in the second and third joints 232 and 233, for example. Therefore, it is possible to obtain the angular velocities ω2 and ω3 based on the measured distance intervals L2, L3, Lsz, the angular velocity ωs detected by the inertial sensor 3, and the translational velocity Vzs calculated from the acceleration Azs detected by the inertial sensor 3. In addition, based on the obtained values of the angular velocities ω2 and ω3, it is possible to determine the vibration amounts of the respective joints of the second joint 232 and the third joint 233.)

[0077] [Equation 5]

[0078]

[0079] [Equation 6]

[0080]

[0081] According to the method described above, it is possible to determine the vibration amounts of the joints of the second joint 232 and the third joint 233 respectively. In particular, based on the interval distances L2, L3, Lsz measured in advance, the angular velocity ωs detected by the inertial sensor 3, and the translational velocity Vzs calculated from the acceleration Azs detected by the inertial sensor 3, it is possible to determine the vibration amounts of the joints of the second joint 232 and the third joint 233 respectively. Therefore, this detection can be easily performed.

[0082] Drive control step S3

[0083] In the drive control step S3, the control device 4 controls the drive of the robotic arm 22 based on the detection result of the vibration detection step S2. Specifically, the control device 4 controls the second joint 232 and the third joint 233 based on the vibration amounts of the respective joints determined in the vibration detection step S2. In this way, by controlling the vibration based on the vibration amounts of the respective joints, more appropriate control can be performed and the vibration can be reduced more reliably and effectively.

[0084] For example, if an example of the control of the second joint 232 is given, then as Figure 11 shown, the control device 4 has a control unit 40 that controls the drive of the second joint 232. In addition, the control unit 40 includes: a position command generation unit 41, a position control unit 42, a speed control unit 43, a current control unit 44, and a vibration feedback generation unit 45.

[0085] The vibration feedback generation unit 45 multiplies the vibration amount, i.e., the angular velocity ω, determined in step S2 based on the angular velocity ωs detected by the inertial sensor 3 and the acceleration Azs detected by the inertial sensor 3 by the arm angular velocity scale factor Kgs to obtain the arm angular velocity 912 in terms of the motor shaft. In addition, the vibration feedback generation unit 45 performs a time differentiation on the rotation angle of the motor M detected by the encoder E, i.e., the motor shaft position 902, to obtain the motor shaft angular velocity 913, which is the angular velocity of the motor shaft. Next, the vibration feedback generation unit 45 subtracts the motor shaft angular velocity 913 from the arm angular velocity 912 in terms of the motor shaft to obtain the vibration angular velocity 914. Next, the vibration feedback generation unit 45 multiplies the vibration angular velocity 914 by the feedback gain Kgp to obtain the vibration feedback 915.

[0086] The position command generation unit 41 generates a position command 901 for the motor M based on a program created by the host computer. First, the position control unit 42 calculates a position deviation 903 obtained by subtracting the motor shaft position 902 detected by the encoder E from the position command 901. Next, the position control unit 42 multiplies the position deviation 903 by the position loop proportional gain Kpp to obtain a speed command 904.

[0087] The speed control unit 43 is constituted by proportional-integral control. First, the speed control unit 43 adds the speed command 904 and the vibration feedback 915 generated by the vibration feedback generation unit 45 to obtain the speed loop command 905. Next, the speed control unit 43 obtains the current command 906 by adding the proportional term obtained by multiplying the speed loop command 905 by the speed loop proportional gain Kvp and the integral term obtained by multiplying the integral value of the speed loop command 905 by the speed loop integral gain Kvi.

[0088] The current control unit 44 controls the current 907 for driving the motor M so that the current 907 for driving the motor M is consistent with the current command 906, that is, the current 907 follows the current command 906. Then, the motor M is driven by the current 907 controlled by the current control unit 44.

[0089] In the above, an example of the control has been described. Next, a configuration example of the inertial sensor 3 will be described in some detail. For example, as Figure 12 shown, when viewed from above in the vertical direction, that is, in the direction orthogonal to the third rotation axis J3 and the central axis A of the third arm 223, the inertial sensor 3 is located on the central axis A of the third arm 223. For the robot system 1, the central axis A is orthogonal to the third rotation axis J3 and parallel to the fourth rotation axis J4. In other words, the central axis A is parallel to the direction in which the third arm and the fourth arm extend. According to such a configuration, it is easy to configure the inertial sensor 3. Moreover, the inertial sensor 3 is arranged at the end on the fourth joint 234 side, that is, the end on the side opposite to the third joint 233. Thereby, the inertial sensor 3 can be arranged as separated from the third rotation axis J3 as much as possible, and thus a larger acceleration Azs can be detected. Here, another example of the central axis A of the arm is an axis that is parallel to the direction in which the arm extends and passes through the center of gravity position of the arm. In addition, the central axis A of the arm may also be an axis parallel to the line segment connecting the center of gravity position of the joint connecting the arm to the front end side to the center of gravity position of the joint connecting the arm to the base end side. By arranging the inertial sensor 3 to acquire the acceleration Azs in the direction orthogonal to the central axis A of the arranged arm, the acceleration generated by the turning motion of the arm generated by the driving of at least one of the base end side joint and the front end side joint can be detected with good accuracy.

[0090] In addition, for example, as Figure 13As shown, when a motor M serving as a drive source is disposed within the third arm 223, the inertial sensor 3 is disposed separately from the motor M. Thus, vibrations generated by the drive of the motor M are less likely to be transmitted to the inertial sensor 3, and the angular velocity ωs and the acceleration Azs can be accurately detected by the inertial sensor 3. It should be noted that the motor M disposed within the third arm 223 can also be the motor M provided in any joint. For example, it can be the motor M provided in the third joint 233 or the motor M provided in the fourth joint 234.

[0091] In addition, for example, as Figure 14 shown, the inertial sensor 3 is disposed within the third arm 223. Thus, the inertial sensor 3 can be protected from moisture, dust, etc. In addition, the inertial sensor 3 is disposed on the wall portion of the third arm 223. Specifically, the third arm 223 has a housing 223a connected to another arm and a cover 223b fitted to the housing 223a, and the inertial sensor 3 is disposed on the wall portion of the cover 223b. Since a speed reducer and the motor M are fixed to the housing 223a, by disposing the inertial sensor 3 on the cover 223b, vibrations generated by the speed reducer and the motor M are less likely to be transmitted to the inertial sensor 3. Therefore, the angular velocity ωs and the acceleration Azs can be accurately detected by the inertial sensor 3.

[0092] In addition, for example, as Figure 15 shown, the wall portion, that is, the cover 223b has an inner wall 223c, an outer wall 223d, and a hollow portion 223e located between the inner wall 223c and the outer wall 223d, and the inertial sensor 3 is disposed in the hollow portion 223e. In this way, by accommodating the inertial sensor 3 within the cover 223b, the inertial sensor 3 can be protected from moisture, dust, etc. Moreover, the inertial sensor 3 is disposed on the outer wall 223d. Thus, vibrations generated by the speed reducer and the motor M are less likely to be transmitted to the inertial sensor 3. Therefore, the angular velocity ωs and the acceleration Azs can be accurately detected by the inertial sensor 3.

[0093] Above, the robot system 1 has been described. Such a robot system 1 has, as described above: a robot 2 having a robotic arm 22, the robotic arm 22 including a plurality of arms, namely, first, second, third, fourth, fifth, and sixth arms 221, 222, 223, 224, 225, 226, and a plurality of joints, namely, first, second, third, fourth, fifth, and sixth joints 231, 232, 233, 234, 235, 236. The plurality of joints include a second joint 232 as a base-end side joint having second and third rotation axes J2 and J3 that are parallel to each other as rotation axes, and a third joint 233 as a front-end side joint located on the front-end side of the second joint 232; and an inertial sensor 3 disposed on a third arm 223 that connects the third joint 233 and a fourth joint 234 located on the front-end side of the third joint 233. The inertial sensor 3 detects an angular velocity ωs about an axis parallel to the second and third rotation axes J2 and J3 and an acceleration Azs in a direction orthogonal to the central axis A of the third arm 223 on which the inertial sensor 3 is disposed and orthogonal to the second and third rotation axes J2 and J3. According to such a configuration, it is possible to detect the vibration amounts of the respective joints of the second and third joints 232 and 233 based on the relationship between the angular velocity ωs and the acceleration Azs detected by the inertial sensor 3. In addition, by controlling the vibration based on the vibration amounts of the respective joints, it is possible to effectively reduce the vibration of the robotic arm 22. In particular, by disposing the inertial sensor 3 on the third arm 223, it is possible to detect the angular velocity ωs and the acceleration Azs regardless of the posture of the robotic arm 22.

[0094] In addition, as described above, the robot system 1 includes: a robot 2 having a robotic arm 22, the robotic arm 22 including a plurality of arms, i.e., first, second, third, fourth, fifth, and sixth arms 221, 222, 223, 224, 225, 226, and a plurality of joints, i.e., first, second, third, fourth, fifth, and sixth joints 231, 232, 233, 234, 235, 236. The plurality of joints include a second joint 232 as a base-end side joint having second and third rotation axes J2 and J3 that are parallel to each other as rotation axes, and a third joint 233 as a front-end side joint located on the front-end side of the second joint 232; and an inertial sensor 3 disposed in any one of the third, fourth, and fifth arms 223, 224, 225 between the third joint 233 and the sixth joint 236 located on the most front-end side. The inertial sensor 3 detects an angular velocity ωs about an axis parallel to the second and third rotation axes J2 and J3 and an acceleration Azs in a direction orthogonal to the central axis A of the arm in which the inertial sensor 3 is disposed and orthogonal to the second and third rotation axes J2 and J3. With such a configuration, it is possible to detect the vibration amounts of the respective joints of the second and third joints 232 and 233 based on the relationship between the angular velocity ωs and the acceleration Azs detected by the inertial sensor 3. In addition, by controlling the vibration based on the vibration amount of each joint, it is possible to effectively reduce the vibration of the robotic arm 22. In particular, by disposing the inertial sensor 3 so as to avoid the sixth arm 226 located at the most front end, it is possible to minimize the number of joints between the inertial sensor 3 and the third joint 233. Therefore, the angular velocity ωs and the acceleration Azs can be easily detected without being affected by the posture of the robotic arm 22.

[0095] In addition, as described above, the robot 2 has a base 21, and the robotic arm 22 has: a first arm 221 connected to the base 21 via a joint different from the base-end side joint and the front-end side joint and different from the front-end side joint, i.e., a first joint 231; a second arm 222 connected to the first arm 221 via a second joint 232 as a base-end side joint; and a third arm 223 connected to the second arm 222 via a third joint 233 as a front-end side joint. In addition, an inertial sensor 3 is disposed in the third arm 223. With such a configuration, in any posture of the robotic arm 22, the detection axis of the angular velocity detection element 31a also remains in a state parallel to the second and third rotation axes J2 and J3, and the detection axis of the acceleration detection element 32a also remains in a state orthogonal to the second and third rotation axes J2 and J3. Therefore, the angular velocity ωs and the acceleration Azs can be detected more reliably.

[0096] In addition, as described above, when viewed from above in a direction orthogonal to the second and third rotation axes J2 and J3 and the central axis A of the third arm 223, the inertial sensor 3 is located on the central axis A of the third arm 223. With such a configuration, it is easy to dispose the inertial sensor 3.

[0097] In addition, as described above, the inertial sensor 3 is disposed at the end of the third arm 223 on the side opposite to the third joint 233. Thus, the inertial sensor 3 can be disposed as far as possible from the third rotation axis J3, and therefore a larger acceleration Azs can be detected.

[0098] In addition, as described above, the robot 2 has a motor M disposed inside the third arm 223 and serving as a drive source for driving the robotic arm 22. Further, the inertial sensor 3 is disposed separately from the motor M. Thus, the vibration generated by the drive of the motor M is less likely to be transmitted to the inertial sensor 3, and the angular velocity ωs and the acceleration Azs can be accurately detected by the inertial sensor 3.

[0099] In addition, as described above, the inertial sensor 3 is disposed inside the third arm 223. Thus, the inertial sensor 3 can be protected from moisture, dust, etc.

[0100] In addition, as described above, the inertial sensor 3 is disposed on the cover 223b which is a wall portion of the third arm 223. Thus, the vibration generated from the speed reducer and the motor M is less likely to be transmitted to the inertial sensor 3. Therefore, the angular velocity ωs and the acceleration Azs can be accurately detected by the inertial sensor 3.

[0101] In addition, as described above, the cover 223b which is a wall portion has: an inner wall 223c, an outer wall 223d, and a hollow portion 223e located between the inner wall 223c and the outer wall 223d. Further, the inertial sensor 3 is disposed in the hollow portion 223e. Thus, the inertial sensor 3 can be protected from moisture, dust, etc.

[0102] Second Embodiment

[0103] Figure 16 is a schematic diagram showing a robot according to the second embodiment. Figure 17 is a diagram showing the arrangement of the inertial sensor.

[0104] The robot system 1 according to the present embodiment is the same as the robot system 1 of the foregoing first embodiment except for the configuration and arrangement of the inertial sensor 3. It should be noted that in the following description, for the robot system 1 of the present embodiment, the description will focus on the differences from the foregoing first embodiment, and the description of the same matters will be omitted. In addition, in the respective drawings of the present embodiment, the same reference numerals are given to the same configurations as those of the foregoing embodiment.

[0105] As Figure 16As shown, in the robot system 1 of the present embodiment, an inertial sensor 3 is disposed on the fourth arm 224. The inertial sensor 3 detects an acceleration Azs in a direction orthogonal to the central axis of the fourth arm 224 and orthogonal to the second and third rotation axes J2 and J3. In this way, by disposing the inertial sensor 3 on the fourth arm 224, the inertial sensor 3 can be disposed further apart from the second and third rotation axes J2 and J3, and thus a larger acceleration Azs can be detected. Therefore, it is possible to more accurately determine the vibration amounts of the joints of the second joint 232 and the third joint 233 respectively.

[0106] In such a configuration, the detection axis of the inertial sensor 3 rotates relative to the second and third rotation axes J2 and J3 as the fourth joint 234 rotates. Therefore, in a configuration having one angular velocity detection element 31a and one acceleration detection element 32a like the inertial sensor 3 in the first embodiment described above, the angular velocity ωs and the acceleration Azs cannot be detected depending on the orientation of the fourth joint 234.

[0107] Therefore, the inertial sensor 3 of the present embodiment further includes an angular velocity detection element 31b in addition to the angular velocity detection element 31a, and the angular velocity detection element 31b has a detection axis orthogonal to the detection axis of the angular velocity detection element 31a and the fourth rotation axis J4. In addition, the inertial sensor 3 of the present embodiment further includes an acceleration detection element 32b in addition to the acceleration detection element 32a, and the acceleration detection element 32b has a detection axis orthogonal to the detection axis of the acceleration detection element 32a and the fourth rotation axis J4. That is, the inertial sensor 3 can detect the angular velocity about two axes orthogonal to each other and orthogonal to the fourth rotation axis J4 and the acceleration in the directions of two axes orthogonal to each other and orthogonal to the fourth rotation axis J4. According to such a configuration, regardless of the orientation of the fourth joint 234, the angular velocity ωs can be detected based on the angular velocities detected by the angular velocity detection elements 31a and 31b, and the acceleration Azs can be detected based on the accelerations detected by the acceleration detection elements 32a and 32b.

[0108] In addition, as Figure 17 shown, the inertial sensor 3 is disposed on the fourth rotation axis J4 of the fourth arm 224. Therefore, regardless of the orientation of the fourth arm 224, the positional relationship between the second and third rotation axes J2 and J3 and the inertial sensor 3 remains constant. Therefore, the calculation of the angular velocity ωs and the acceleration Azs is facilitated.

[0109] As described above, the robot system 1 of the present embodiment includes: a robot 2 having a robotic arm 22, the robotic arm 22 including a plurality of arms, namely, first, second, third, fourth, fifth, and sixth arms 221, 222, 223, 224, 225, 226, and a plurality of joints, namely, first, second, third, fourth, fifth, and sixth joints 231, 232, 233, 234, 235, 236. The plurality of joints include a second joint 232 as a proximal-side joint having second and third rotation axes J2 and J3 that are parallel to each other as rotation axes, and a third joint 233 as a distal-side joint located on the distal side of the second joint 232; and an inertial sensor 3 disposed on a fourth arm 224 that connects a fourth joint 234, which is a joint on the distal side immediately before the third joint 233, and a fifth joint 235, which is a joint on the distal side immediately before that. The inertial sensor 3 detects an angular velocity ωs about an axis parallel to the second and third rotation axes J2 and J3 and an acceleration Azs in a direction orthogonal to the central axis of the fourth arm 224 on which the inertial sensor 3 is disposed and orthogonal to the second and third rotation axes J2 and J3. With such a configuration, it is possible to detect the vibration amounts of the second and third joints 232 and 233 based on the relationship between the angular velocity ωs and the acceleration Azs detected by the inertial sensor 3. In addition, by controlling the vibration based on the vibration amounts of the respective joints, it is possible to effectively reduce the vibration of the robotic arm 22. In particular, by disposing the inertial sensor 3 on the fourth arm 224, the inertial sensor 3 can be disposed further apart from the second and third rotation axes J2 and J3, and thus a larger acceleration Azs can be detected. Therefore, it is possible to more accurately determine the vibration amounts of the second and third joints 232 and 233.

[0110] In addition, as described above, the robot 2 has a base 21, and the robotic arm 22 has: a first arm 221 connected to the base 21 via a first joint 231 which is a joint different from both the proximal-side joint and the distal-side joint; a second arm 222 connected to the first arm 221 via a second joint 232 which is a proximal-side joint; a third arm 223 connected to the second arm 222 via a third joint 233 which is a distal-side joint; and a fourth arm 224 connected to the third arm 223 via a fourth joint 234 which is a joint different from both the proximal-side joint and the distal-side joint. Further, an inertial sensor 3 is disposed on the fourth arm 224, and the inertial sensor 3 detects the angular velocity about two axes orthogonal to each other and orthogonal to the fourth rotation axis J4 and the acceleration in the directions of two axes orthogonal to each other and orthogonal to the fourth rotation axis J4. With such a configuration, the angular velocity ωs and the acceleration Azs can be detected regardless of the orientation of the fourth joint 234. In addition, the inertial sensor 3 can be separately disposed from the second and third rotation axes J2 and J3, and thus a larger acceleration Azs can be detected. Therefore, the vibration amounts of the joints of the second and third joints 232 and 233 can be determined with better accuracy.

[0111] In addition, as described above, the inertial sensor 3 is located on the fourth rotation axis J4 which is the rotation axis of the fourth arm 224. Therefore, regardless of the orientation of the fourth arm 224, the positional relationship between the second and third rotation axes J2 and J3 and the inertial sensor 3 remains constant. Therefore, the calculation of the angular velocity ωs and the acceleration Azs is facilitated.

[0112] With such a second embodiment, the same effects as those of the foregoing first embodiment can also be achieved.

[0113] Third Embodiment

[0114] Figure 18 FIG. is a schematic view showing the robot according to the third embodiment.

[0115] The robot system 1 according to the present embodiment is the same as the robot system 1 of the foregoing first embodiment except for the configuration of the inertial sensor 3. It should be noted that in the following description, the robot system 1 of the present embodiment will be mainly described with respect to the differences from the foregoing first embodiment, and the description of the same matters will be omitted. In addition, in the drawings of the present embodiment, the same reference numerals are given to the same configurations as those of the foregoing embodiments.

[0116] For example, when in a posture where the second and third arms 222 and 223 are orthogonal as Figure 9 shown, the acceleration Azs generated by the vibration of the second joint 232 is small, and the translational velocity Vzs is also small. Therefore, it may be impossible to accurately determine the vibration amounts of the joints of the second joint 232 and the third joint 233.

[0117] Therefore, as Figure 18 shown, the inertial sensor 3 of the present embodiment includes, in addition to the acceleration detection element 32a, an acceleration detection element 32b having a detection axis orthogonal to the detection axis of the acceleration detection element 32a and the second and third rotation axes J2, J3. With such a configuration, the detection axis of the acceleration detection element 32a is substantially aligned with the direction of the acceleration generated by the vibration of the second joint 232, and a larger acceleration can be detected by the acceleration detection element 32b. Therefore, the vibration amounts of the joints of the second joint 232 and the third joint 233 can be determined with high accuracy.

[0118] It should be noted that, in Figure 18 , the vertical translation speed Vzs of the inertial sensor 3 is expressed as Vzs = L2 × ω2 + √(L3 2 + Lsz 2 ) × ω3, and the horizontal translation speed Vxs is expressed as Vxs = L2 × ω2. Therefore, the following equation (7) holds. In addition, the vibration amounts of the joints of the second joint 232 and the third joint 233 can be determined based on the values of the angular velocities ω2 and ω3 obtained from equation (7).

[0119] [Equation 7]

[0120]

[0121] Through such a third embodiment, the same effects as those of the foregoing first embodiment can also be achieved.

[0122] Fourth Embodiment

[0123] Figure 19 is a schematic diagram showing the robot according to the fourth embodiment.

[0124] The robot system 1 according to the present embodiment is the same as the robot system 1 of the foregoing first embodiment except for the configuration of the inertial sensor 3. It should be noted that in the following description, the robot system 1 of the present embodiment will be described centering on the differences from the foregoing first embodiment, and the description of the same matters will be omitted. In addition, in the drawings of the present embodiment, the same reference numerals are given to the same configurations as those of the foregoing embodiments.

[0125] In the robot system 1 of the present embodiment, the inertial sensor 3 is configured to be able to detect vibrations about the first rotation axis J1 of the first joint 231. Specifically, as Figure 19As shown, in addition to the angular velocity detection element 31a, the inertial sensor 3 of the present embodiment further includes angular velocity detection elements 31c and 31d, and the angular velocity detection elements 31c and 31d have detection axes that are orthogonal to the detection axis of the angular velocity detection element 31a and orthogonal to each other. According to such a configuration, regardless of the orientations of the second and third joints 232 and 233, it is possible to detect vibrations around the first rotation axis J1 of the first joint 231 based on the angular velocities detected by the angular velocity detection elements 31c and 31d. It should be noted that, for the sake of convenience of explanation, the acceleration detection element 32a is not shown in the drawings.

[0126] Through such a fourth embodiment, the same effects as those of the foregoing first embodiment can also be achieved.

[0127] Fifth Embodiment

[0128] Figure 20 It is a schematic diagram showing a robot according to the fifth embodiment.

[0129] The robot system 1 according to the present embodiment is the same as the robot system 1 of the foregoing first embodiment except for the configuration of the robot 2 and the arrangement of the corresponding inertial sensor 3. It should be noted that in the following description, for the robot system 1 of the present embodiment, the description will focus on the differences from the foregoing first embodiment, and the description of the same matters will be omitted. In addition, in the drawings of the present embodiment, the same reference numerals are given to the same configurations as those of the foregoing embodiments.

[0130] As Figure 20 shown, the robot 2 of the present embodiment is a seven-axis vertical multi-joint robot having seven drive axes. In addition, the robotic arm 22 is configured such that the first, second, third, fourth, fifth, sixth, and seventh arms 221, 222, 223, 224, 225, 226, and 227 are connected via the first, second, third, fourth, fifth, sixth, and seventh joints 231, 232, 233, 234, 235, 236, and 237.

[0131] Specifically, the first arm 221 is connected to the base 21 via the first joint 231 so as to be rotatable about the first rotation axis J1. In addition, the second arm 222 is connected to the first arm 221 via the second joint 232 so as to be rotatable about the second rotation axis J2. In addition, the third arm 223 is connected to the second arm 222 via the third joint 233 so as to be rotatable about the third rotation axis J3. In addition, the fourth arm 224 is connected to the third arm 223 via the fourth joint 234 so as to be rotatable about the fourth rotation axis J4. In addition, the fifth arm 225 is connected to the fourth arm 224 via the fifth joint 235 so as to be rotatable about the fifth rotation axis J5. In addition, the sixth arm 226 is connected to the fifth arm 225 via the sixth joint 236 so as to be rotatable about the sixth rotation axis J6. In addition, the seventh arm 227 is connected to the sixth arm 226 via the seventh joint 237 so as to be rotatable about the seventh rotation axis J7.

[0132] In addition, among the first, second, third, fourth, fifth, sixth, and seventh joints 231, 232, 233, 234, 235, 236, 237, the second, fourth, and sixth joints 232, 234, 236 are bending joints respectively, and the first, third, fifth, and seventh joints 231, 233, 235, 237 are torsion joints respectively. In addition, the second rotation axis J2 is orthogonal to the first rotation axis J1, the third rotation axis J3 is orthogonal to the second rotation axis J2, the fourth rotation axis J4 is orthogonal to the third rotation axis J3, the fifth rotation axis J5 is orthogonal to the fourth rotation axis J4, the sixth rotation axis J6 is orthogonal to the fifth rotation axis J5, and the seventh rotation axis J7 is orthogonal to the sixth rotation axis J6.

[0133] In addition, an inertial sensor 3 is disposed on the third arm 223. The inertial sensor 3 can detect the angular velocity ωs about the axis parallel to the third rotation axis J3 and the acceleration Axs in the direction orthogonal to the third rotation axis J3.

[0134] In such a robot 2, the first joint 231 is the "base - end - side joint" of the present application, and the third joint 233 is the "front - end - side joint" of the present application. That is, in the robot 2, the second joint 232 is located between the base - end - side joint and the front - end - side joint. In the robot 2, as Figure 20 shown, when the second joint 232 is in a predetermined orientation, the first rotation axis J1 of the first joint 231 serving as the base - end - side joint is parallel to the third rotation axis J3 of the third joint 233 serving as the front - end - side joint. Therefore, the vibration amounts of the joints of the first joint 231 and the third joint 233 can be detected by the same method as in the foregoing first embodiment.

[0135] As described above, the robot 2 of the present embodiment has a base 21. In addition, the robotic arm 22 includes: a first arm 221 connected to the base 21 via a first joint 231 serving as a base-end side joint; a second arm 222 connected to the first arm 221 via a second joint 232 serving as a joint different from the base-end side joint and different from the front-end side joint; and a third arm 223 connected to the second arm 222 via a third joint 233 serving as a front-end side joint. Further, an inertial sensor 3 is disposed on the third arm 223. With such a configuration, when the second joint 232 is in a predetermined orientation, a first rotation axis J1 of the first joint 231 serving as a base-end side joint is parallel to a third rotation axis J3 of the third joint 233 serving as a front-end side joint, and the vibration amounts of the respective joints of the first and third joints 231 and 233 can be detected.

[0136] Through such a fifth embodiment, the same effects as those of the foregoing first embodiment can also be achieved.

[0137] Sixth Embodiment

[0138] Figure 21 FIG. is a diagram showing a robot according to the sixth embodiment.

[0139] The robot system 1 according to the present embodiment is the same as the robot system 1 of the foregoing first embodiment except for the configuration of the robot 5 and the arrangement of the corresponding inertial sensor 3. It should be noted that in the following description, the robot system 1 of the present embodiment will be mainly described with respect to the differences from the foregoing first embodiment, and the description of the same matters will be omitted. In addition, in the drawings of the present embodiment, the same reference numerals are given to the same configurations as those of the foregoing embodiments.

[0140] As Figure 21 shown, the robot 5 of the present embodiment is a horizontal multi-joint robot (SCARA robot). Such a robot 5 has a base 51 and a robotic arm 52 connected to the base 51. In addition, the robotic arm 52 is configured such that the first and second arms 521 and 522 are connected via the first and second joints 541 and 542.

[0141] The first arm 521 is connected to the base 21 via the first joint 541 so as to be rotatable about a first rotation axis J11. In addition, the second arm 522 is connected to the first arm 521 via the second joint 542 so as to be rotatable about a second rotation axis J12. Further, these first and second joints 541 and 542 are respectively torsion joints, and the first and second rotation axes J11 and J12 are parallel and extend along the vertical direction.

[0142] In addition, an operation head 53 is provided at the front end of the second arm 522. The operation head 53 includes a spline nut 531 and a ball screw nut 532 coaxially arranged at the front end of the second arm 522, and a spline shaft 533 serving as a main shaft inserted into the spline nut 531 and the ball screw nut 532. The spline shaft 533 is centered on the second arm 522, can rotate about a third rotation axis J13 along the vertical direction, and can move (lift) along the third rotation axis J13. In addition, an assembly portion 533a for assembling an end effector (not shown) is provided at the lower end of the spline shaft 533. The end effector is detachable from and attachable to the assembly portion 533a, and is appropriately selected to suit the target operation. It should be noted that the third rotation axis J13 is along the vertical direction and is parallel to the first and second rotation axes J11 and J12.

[0143] In such a robot 5, the first joint 541 is the "base end side joint" of the present application, and the second joint 542 is the "front end side joint" of the present application.

[0144] In addition, each of the joints 541 and 542 includes: a motor M, a speed reducer (not shown) that reduces the rotation speed of the motor M and outputs it, and an encoder E that detects the rotation amount of the motor M.

[0145] In addition, as Figure 21 shown, the inertial sensor 3 is disposed on the second arm 522. In addition, the inertial sensor 3 includes: an angular velocity detection element 31a that detects the angular velocity ωs about an axis in the same orientation as the first and second rotation axes J11 and J12; and an acceleration detection element 32a that detects the acceleration Axs in a direction orthogonal to the first and second rotation axes J11 and J12.

[0146] In the robot system 1 configured as described above, it is also possible to detect the vibration amounts of the joints of the first joint 541 and the second joint 542 by the same method as in the foregoing first embodiment.

[0147] Through such a sixth embodiment, the same effects as those of the foregoing first embodiment can also be achieved.

[0148] Above, through the illustrated embodiments, the control method of the robot and the robot system of the present invention have been described, but the present invention is not limited thereto. The configurations and processes of each part can be replaced with any configurations and processes having the same functions. In addition, any other configurations and processes can be added to the present invention. In addition, the embodiments can be appropriately combined.

Claims

1. A robot system, characterized in that: have: A robot having a robot arm, the robot arm including a plurality of arms and a plurality of joints, the plurality of joints including a base end side joint having rotation axes parallel to each other and a front end side joint located on the front end side of the base end side joint; as well as an inertial sensor disposed on the arm connecting the front end joint to the joint located on the front end side of the front end joint; The inertial sensor detects an angular velocity about an axis parallel to the rotation axis and an acceleration in a direction orthogonal to a central axis of the arm on which the inertial sensor is disposed and to the rotation axis.

2. A robot system, characterized in that: have: A robot having a robot arm, the robot arm including a plurality of arms and a plurality of joints, the plurality of joints including a base end side joint having rotation axes parallel to each other and a front end side joint located on the front end side of the base end side joint; as well as an inertial sensor disposed on the arm connecting the joint located at the front end side one front of the front end side joint and the joint located at the front end side one front of the front end side joint, The inertial sensor detects an angular velocity about an axis parallel to the rotation axis and an acceleration in a direction orthogonal to a central axis of the arm on which the inertial sensor is disposed and to the rotation axis.

3. A robot system, characterized in that: have: A robot having a robot arm, the robot arm including a plurality of arms and a plurality of joints, the plurality of joints including a base end side joint having rotation axes parallel to each other and a front end side joint located on the front end side of the base end side joint; as well as an inertial sensor disposed on the arm between the front end joint and the joint located at the most front end side, The inertial sensor detects an angular velocity about an axis parallel to the rotation axis and an acceleration in a direction orthogonal to a central axis of the arm on which the inertial sensor is disposed and to the rotation axis.

4. The robot system according to claim 1 or 3, characterized in that: The robot has a base. The robot arm comprises a first arm, a second arm and a third arm, the first arm being connected to the base via the joint different from the base end joint and different from the front end joint, the second arm being connected to the first arm via the base end joint, and the third arm being connected to the second arm via the front end joint. The inertial sensor is disposed on the third arm.

5. The robot system according to claim 4, characterized in that: The inertial sensor is located on the central axis of the third arm when viewed in plan from a direction perpendicular to the rotation axis and the central axis of the third arm.

6. The robot system according to claim 4, characterized in that: The inertial sensor is disposed at an end portion of the third arm on the opposite side from the distal joint.

7. The robot system according to claim 4, characterized in that: The robot has a driving source disposed in the third arm and driving the robot arm, The inertial sensor is arranged separately from the driving source.

8. The robot system according to claim 4, characterized in that: The inertial sensor is disposed within the third arm.

9. The robot system according to claim 8, characterized in that: The inertial sensor is arranged on a wall portion of the third arm.

10. The robot system according to claim 8, characterized in that: The wall portion has an inner wall, an outer wall, and a hollow portion between the inner wall and the outer wall. The inertial sensor is disposed in the hollow portion.

11. The robot system according to claim 2, characterized in that: The robot has a base. The robot arm comprises a first arm, a second arm, a third arm and a fourth arm, the first arm being connected to the base via the joint different from the base end joint and different from the front end joint, the second arm being connected to the first arm via the base end joint, the third arm being connected to the second arm via the front end joint, and the fourth arm being connected to the third arm via the joint different from the base end joint and different from the front end joint. The inertial sensor is disposed on the fourth arm, The inertial sensor detects angular velocity about two axes that are orthogonal to the rotation axis of the fourth arm and are orthogonal to each other, and acceleration in two axial directions that are orthogonal to the rotation axis of the fourth arm and are orthogonal to each other.

12. The robot system according to claim 11, characterized in that: The inertial sensor is located on the rotation axis of the fourth arm.

13. The robot system according to claim 1 or 2, characterized in that: The robot has a base. The robot arm comprises a first arm, a second arm and a third arm, the first arm being connected to the base via the base end joint, the second arm being connected to the first arm via the joint different from the base end joint and different from the front end joint, and the third arm being connected to the second arm via the front end joint. The inertial sensor is disposed on the third arm.

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