Robots and robotic systems

Abstract

To provide robots and robotic systems equipped with inertial sensors. [Solution] The robot 1 comprises a base 110, a first arm 120 overlapping the base 110, a joint 25 that holds the first arm 120 so as to be rotatable around a first axis J1, a second arm 130 overlapping the first arm 120, a joint 35 provided on the second arm 130 that holds the second arm 130 so as to be rotatable around a second axis J2, and an operating shaft 41 provided on the second arm 130, and the second arm The device 130 includes a housing 131 having a bottom plate 1311, a motor 51 positioned on the upper surface 1311a side of the bottom plate 1311 between the operating shaft 41 and the second shaft J2, which rotates the operating shaft 41 around the third shaft J3, and an inertial sensor 8 positioned on the lower surface 1311b side of the bottom plate 1311 in a position that overlaps with the motor 51 in a plan view, which detects at least one of angular velocity and acceleration.

Description

Technical Field

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

Background Art

[0002] As an industrial robot, for example, the scalar robot described in Patent Document 1 is known. The scalar robot described in Patent Document 1 includes a base, a first arm connected to the base by a drive shaft of a scalar robot unit, a second arm having one end connected to the drive shaft of a second motor unit on the first arm, and an end effector provided at the other end of the second arm.

[0003] Furthermore, the scalar robot described in Patent Document 1 includes a gyro sensor module having an angular velocity sensor on the second arm, and uses the information on the angular velocity detected by the angular velocity sensor to control the drive of the first motor unit and / or the second motor unit so that the horizontal vibration caused by the drive of the second arm is suppressed.

[0004] In the scalar robot described in Patent Document 1, the gyro sensor module is provided between the drive shaft of the second motor unit of the second arm and the slide shaft of the end effector. More specifically, the gyro sensor module is provided in the space between the slide shaft of the end effector and the drive unit of the end effector.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In SCARA robots equipped with inertial sensor modules, space is required on the second arm to accommodate the inertial sensor modules. Therefore, the challenge lies in how to position the inertial sensor modules while ensuring the detection accuracy of the inertial sensors and the basic performance of the SCARA robot. [Means for solving the problem]

[0007] The robot of the present invention comprises a base, a first arm whose longitudinal end overlaps the base in a plan view, a first joint provided on the one end of the first arm and which holds the first arm so as to be rotatable around a first axis relative to the base, a second arm whose longitudinal end overlaps the other longitudinal end of the first arm in a plan view, a second joint provided on the one end of the second arm and which holds the second arm so as to be rotatable around a second axis parallel to the first axis relative to the first arm, and on the other longitudinal end of the second arm The second arm comprises a shaft and a housing portion having a first plate portion, a motor positioned between the shaft and the second axis on the first surface side of the first plate portion and rotating the shaft around a third axis parallel to the second axis, or moving it along the third axis, and an inertial sensor positioned on the second surface side of the first plate portion opposite the first surface, in a plan view, at a position overlapping with the motor, or at a position closer to the second axis than the motor, and detecting at least one of angular velocity and acceleration.

[0008] The robot system of the present invention comprises the robot and a controller for controlling the robot. [Brief explanation of the drawing]

[0009] [Figure 1] An overall perspective view of the robot system equipped with the robot of this embodiment. [Figure 2] A partially enlarged perspective view of Figure 1. [Figure 3] Side view of the robot in Figure 1. [Figure 4A] Partial cross-sectional view of the robot in Figure 3. [Figure 4B] Figure 3 is a plan view of the robot as seen from the negative Z-axis side. [Figure 5] Block diagram of the robot system shown in Figure 1. [Figure 6A] A partial cross-sectional view of the robot according to Embodiment 2. [Figure 6B] A side view of the robot according to Embodiment 2, viewed from the negative X-axis side. [Figure 6C] A plan view of the robot according to Embodiment 2, viewed from the negative Z-axis side. [Figure 7A] A partial cross-sectional view of the robot according to Embodiment 3. [Figure 7B] A plan view of the robot according to Embodiment 3, seen from the negative Z-axis side. [Modes for carrying out the invention]

[0010] In embodiments of the present invention, the components shown in each drawing may be shown at different dimensional scales for clarity. Drawings sometimes depict three axes: the X, Y, and Z axes, which are mutually orthogonal. The X and Y axes are positioned so that the plane containing them is horizontal, while the Z axis is positioned so that the tip of the arrow points vertically upward.

[0011] In the following explanation, the tip of the arrows on the three axes may be referred to as the "positive side," and the base of the arrow as the "negative side." The direction parallel to the X-axis may be referred to as the "X-axis direction," the direction parallel to the Y-axis as the "Y-axis direction," and the direction parallel to the Z-axis as the "Z-axis direction."

[0012] In the following, "planar view" refers to viewing an object from either the positive Z-axis side or the negative Z-axis side of the object. The positive Z-axis side may be described as "upwards," and the negative Z-axis side may be described as "downwards."

[0013] In addition, the description of the upper surface of a certain structure shall indicate the surface on the plus side in the Z-axis direction of the said structure. For example, the "upper surface of the plate portion" shall indicate the surface on the plus side in the Z-axis direction of the plate portion. In addition, the description of the lower surface of a certain structure shall indicate the surface on the minus side in the Z-axis direction of the said structure. For example, the "lower surface of the plate portion" shall indicate the surface on the minus side in the Z-axis direction of the plate portion.

[0014] Hereinafter, as preferred embodiments of the robot 1 and the robot system 100 of the present invention, three embodiments will be described.

[0015] 1. Embodiment 1 1.1. Overall configuration of the robot and the robot system FIG. 1 is an overall perspective view of a robot system 100 including the robot 1 of Embodiment 1. FIG. 2 is a partial enlarged perspective view of FIG. 1.

[0016] The robot system 100 is an industrial robot that automates various operations such as assembly in factories, etc., replacing humans. The robot system 100 includes a robot 1, an inertial sensor 8 that detects the vibration of the robot 1, and a control device 7 that controls the robot 1.

[0017] The robot 1 is a horizontal articulated robot (SCARA Robot) whose arm operates in the horizontal direction. In this embodiment, as an example of the robot 1, a ceiling-mounted scalar robot in which the robot 1 is suspended from the ceiling of the gantry 9 will be described. Note that the robot 1 may be a type of scalar robot installed on the floor or a workbench.

[0018] The gantry 9 is installed, for example, on the production line of a factory that manufactures precision devices such as mobile phones, smartphones, and tablet terminals. The robot 1 is controlled by the control device 7 and performs operations such as gripping, transporting, processing, and assembling on the workpiece 95 such as precision devices and parts placed on the workbench 92. The installation surface for the ceiling-mounted robot 1 is not limited to the top plate 91 of the frame 9. The installation surface for the ceiling-mounted robot 1 may be, for example, the ceiling or walls of the workroom, beams, columns, braces, other structural elements, or hoist rails. The ceiling-mounted robot 1 also includes wall-mounted and wall-attached robots that use the side wall as their installation surface.

[0019] The frame 9 has a top plate 91, a work surface 92, and frame-shaped legs 93. Robot 1 is placed on the top plate 91. The top plate 91 has an upper surface 911 and a lower surface 912, and is positioned so that the surface on which Robot 1 is placed is horizontal.

[0020] The top plate 91 has through holes 913 and 914 that penetrate in the direction of its thickness. Through hole 913 is a window that allows an operator to access the top plate 91 from above when performing maintenance on the drive unit 30, etc., which will be described later. Through hole 914 is a hole through which the robot 1 is installed, and the base 110 is inserted through through hole 914.

[0021] As shown in Figure 2, the robot 1 has a base 110 and a robot arm 10 connected to the base 110. The robot arm 10 has a first arm 120, a second arm 130, and a work head 40.

[0022] In a plan view, the first arm 120 is provided so that one end in the longitudinal direction overlaps the base 110 via a joint 25. The joint 25 is provided on one end of the first arm 120 in the longitudinal direction and holds the first arm 120 so that it can rotate around the first axis J1 relative to the base 110. In this embodiment, the first axis J1 is a virtual axis extending along the vertical direction and represents the axis of rotation of the first arm 120. In this embodiment, the joint 25 is an example of a first joint.

[0023] In a plan view, the second arm 130 is provided such that one end in the longitudinal direction overlaps the other end in the longitudinal direction of the first arm 120 via a joint 35. The joint 35 is provided on one end in the longitudinal direction of the second arm 130 and holds the second arm 130 so that it can rotate around a second axis J2 parallel to the first axis J1 relative to the first arm 120. In this embodiment, the second axis J2 is a virtual axis extending along the vertical direction and represents the axis of rotation of the second arm 130. The second axis J2 and the first axis J1 are parallel. In this embodiment, the joint 35 is an example of a second joint.

[0024] The working head 40 is provided on the other end of the second arm 130 in the longitudinal direction. The working head 40 comprises an operating shaft 41 and a hand 42. In this embodiment, the operating shaft 41 is an example of a shaft.

[0025] An inertial sensor 8 is installed on the underside of the second arm 130. The inertial sensor 8 detects vibrations in the second arm 130 and sends a detection signal consisting of vibration data to the control device 7. Based on the detection signal detected by the inertial sensor 8, the control device 7 controls each part of the robot 1 so that vibrations of the robot 1 are suppressed.

[0026] Thus, the robot system 100 of this embodiment can improve vibration damping performance because the robot 1 is equipped with an inertial sensor 8. Therefore, it is possible to realize a robot 1 and robot system 100 that are capable of servo control with excellent speed, accuracy, and / or energy efficiency. Furthermore, in this embodiment, the arrangement of the inertial sensors 8 is designed to achieve both accuracy in the vibration data and workability of the robot 1. The arrangement of the inertial sensors 8 will be explained in section 1.2.3.1 below.

[0027] 1.2. Detailed Configuration of the Robot The detailed configuration of each part of robot 1 will be described below based on Figures 3 to 4B. Figure 3 is a side view of robot 1 in Figure 1. Figure 4A is a partial cross-sectional view of robot 1 in Figure 3. Figure 4B is a plan view of robot 1 in Figure 3, viewed from the negative Z-axis side.

[0028] As shown in Figure 3, the robot 1 has a base 110 and a robot arm 10 connected to the base 110.

[0029] 1.2.1. Base The base 110 is located at the very top of the robot 1 and is attached to the top plate 91 of the frame 9. The base 110 comprises a main body 11, a plate-shaped base plate 13 provided at the lower part of the main body 11, and a drive unit 20 provided inside the main body 11 that rotates the first arm 120 around the first axis J1.

[0030] The main body 11 and the base plate 13 constitute the housing, and a portion of the drive unit 20 is housed within the housing. The base 110 is installed on the top plate 91 by fixing the base plate 13 together with the fittings 12 to the top surface 911 and / or bottom surface 912 of the top plate 91 using fastening members such as bolts, screws, and pins. Robot 1 functions as a ceiling-mounted SCARA robot when its base 110 is installed on the top plate 91.

[0031] The drive unit 20 includes a motor 21, a belt 22, a pulley 23, and a joint 25. The rotation of the motor 21 is transmitted to the joint 25 via the belt 22 and pulley 23. Since the motor 21, belt 22, and pulley 23 are housed within the main body 11, foreign matter such as dust and dirt is prevented from entering the motor 21 and other components, and foreign matter is prevented from being discharged from the motor 21 and other components to the outside of the robot arm 10.

[0032] The joint portion 25 includes a reduction gear 26 and a flange 27. In this embodiment, the speed reducer 26 is a harmonic drive gear speed reducer. However, the speed reducer 26 may be other types of speed reducers, such as a planetary gear speed reducer. One side of the flange 27 is fixed to the output shaft of the reduction gear 26, and the other side is fixed to the first arm 120.

[0033] The gearbox 26 includes a wave generator 261, a flex spline 262, and a circular spline 263. The wave generator 261 is the input shaft of the gearbox 26 and is fixed to the pulley 23. The flex spline 262 is the output shaft of the gearbox 26 and is fixed to the flange 27. The circular spline 263 is the fixed shaft and is fixed to the base plate 13. Alternatively, the flex spline 262 may be fixed to the base plate 13 as the fixed shaft, and the circular spline 263 may be fixed to the flange 27 as the output shaft.

[0034] Cables such as power lines and various signal lines, and / or other piping, which are connected to the drive unit 30, drive unit 50, work head 40, and inertial sensor 8 (described later), are inserted through the hollow tube 28.

[0035] 1.2.2. Robot Arm The robot arm 10 has a first arm 120, a second arm 130, and a work head 40.

[0036] 1.2.2.1. First Arm The first arm 120 is cantilevered to the base 110 via a joint 25 at one end of the horizontally extending arm.

[0037] The first arm 120 rotates around the first axis J1, which is the axis of rotation, and operates horizontally. The first arm 120 is provided with a drive unit 30. The drive unit 30 drives the second arm 130 to rotate around the second axis J2.

[0038] The drive unit 30 includes a motor 31, a belt 32, a pulley 33, and a joint 35. The motor 31 is positioned in the central longitudinal portion of the first arm 120, in other words, approximately midway between the first axis J1 and the second axis J2. The rotation of the motor 31 is transmitted to the joint 35 via the belt 32 and pulley 33. The motor 31 has a portion that protrudes from the housing of the first arm 120 in the positive Z-axis direction. The cover 121 covers the protruding portion of the motor 31.

[0039] The joint portion 35 includes a reduction gear 36 and a flange 37. In this embodiment, the speed reducer 36 is a harmonic drive gear speed reducer. However, the speed reducer 36 may be other types of speed reducers, such as a planetary gear speed reducer.

[0040] The gearbox 36 includes a wave generator 361, a flex spline 362, and a circular spline 363. The wave generator 361 is the input shaft of the gearbox 36 and is fixed to the pulley 33. The flex spline 362 is the output shaft of the gearbox 36 and is fixed to the flange 37. The circular spline 363 is the fixed shaft and is fixed to the first arm 120. Alternatively, the flex spline 362 may be fixed to the first arm 120 as the fixed shaft, and the circular spline 363 may be fixed to the flange 37 as the output shaft.

[0041] One side of the flange 37 is fixed to the output shaft of the reduction gear 36, and the other side is fixed to the second arm 130.

[0042] Cables such as power lines and various signal lines, and / or other piping, which are connected to the drive unit 50, work head 40, and inertial sensor 8 (described later), are inserted through the hollow tube 38.

[0043] 1.2.2.2. Second Arm The second arm 130 is cantilevered to the other end of the first arm 120 via a joint 35 at one end of the horizontally extending arm.

[0044] The second arm 130 moves horizontally by rotating around the second axis J2, which is the axis of rotation. The first axis J1 of the first arm 120 and the second axis J2 of the second arm 130 are parallel, but they are offset horizontally. In other words, the first axis J1 and the second axis J2 are separated by a predetermined distance horizontally. This allows for a wide range of motion for the robot arm 10.

[0045] The second arm 130 has a housing portion 131 and a cylindrical portion 132. The cylindrical portion 132 is provided in the second arm 130 between the housing portion 131 and the flange 37. One side of the cylindrical portion 132 is fixed to the flange 37, and the other side is connected to the housing portion 131. In other words, the cylindrical portion 132 functions as a joint connecting the flange 37 and the housing portion 131. The cylindrical portion 132 is provided so as to surround the second axis J2, and its length along the second axis J2 is such that, for example, the second arm 130 can rotate 360° relative to the first arm 120. For example, the length of the work head 40 from the upper surface 1312a of the top plate 1312 of the housing portion 131 to the upper end of the work head 40 is shorter than the distance along the axial direction of the third axis J3 between the upper surface 1312a of the top plate 1312 of the housing portion 131 to the lower surface of the bottom plate of the first arm 120. As a result, even when the operating axis 41 is at its highest point, the work head 40 does not interfere with the first arm 120, and the second arm 130 can pass below the first arm 120. In other words, the second arm 130 can rotate 360° relative to the first arm 120 regardless of the vertical position of the work head 40. Note that the cylindrical portion 132 is not necessarily required depending on the configuration of the robot 1. For example, in a SCARA robot that is installed on the floor or workbench, the second arm 130 is located above the first arm 120, so the cylindrical portion 132 is not required.

[0046] The housing 131 is equipped with a drive unit 50 and a work head 40. The drive unit 50 has a motor 51, which is controlled by the control device 7 to drive the work head 40.

[0047] The work head 40 includes an operating shaft 41 and a hand 42. The actuation shaft 41 has its longitudinal direction extending along the third axis J3, is driven by the drive unit 50, slides vertically along the third axis J3, and / or rotates around the third axis J3. In this embodiment, the third axis J3 is a virtual axis extending vertically and represents the axis of rotation of the actuation shaft 41. The third axis J3 is parallel to the first axis J1 and the second axis J2.

[0048] The operating shaft 41 is a hollow shaft type with a hollow center. Cables such as power lines and various signal lines, and / or other piping are inserted into the hollow of the operating shaft 41 and connected to the hand 42. Note that the operating shaft 41 is not limited to a hollow shaft type. Cables connected to the hand 42 may also be connected via the outside of the operating shaft 41.

[0049] The hand 42 is an end effector, controlled by the control device 7, which performs tasks such as gripping, transporting, processing, and assembling on workpieces 95, such as precision instruments and parts, placed on the workbench 92.

[0050] The hand 42 is detachably attached to the lower end of the operating shaft 41. The hand 42 is fitted with an end effector suitable for the task, selected from a variety of end effectors. Examples of end effectors include grippers, suction end effectors, application-specific end effectors, and robotic hands.

[0051] The drive unit 50 includes an axis lifting mechanism that slides the operating shaft 41 in the vertical direction, and an axis rotation mechanism that rotates the operating shaft 41 around the third shaft J3.

[0052] The motor 51 includes an axle lifting motor 511 and an axle rotation motor 512. The axle lifting motor 511 and the axle rotation motor 512 are provided adjacent to each other along the longitudinal direction of the second arm 130. In this embodiment, the axle lifting motor 511 is an example of a first motor, and the axle rotation motor 512 is an example of a second motor.

[0053] The shaft lifting mechanism consists of a shaft lifting motor 511, a belt 52, a pulley 53, and a lead screw mechanism 54. The lead screw mechanism 54 consists of a screw groove (not shown) formed on the outer circumferential surface of the operating shaft 41 and a ball screw having a female screw block 541 that is rotatably supported on the top plate 1312 of the housing portion 131.

[0054] The shaft lifting mechanism transmits the rotation of the shaft lifting motor 511 to the female screw block 541 via the belt 52 and pulley 53, and rotates the female screw block 541 to move the operating shaft 41 along the third shaft J3, that is, upward or downward.

[0055] The axial rotation mechanism consists of an axial rotation motor 512, a belt 56, a pulley 57, and a spline mechanism 58. The spline mechanism 58 consists of a spline groove (not shown) formed on the outer circumferential surface of the operating shaft 41 and a ball spline having a boss block 581 that is rotatably supported on the bottom plate 1311 of the housing portion 131. The spline mechanism 58 supports the operating shaft 41 so that it can slide in the vertical direction.

[0056] The axial rotation mechanism transmits the rotation of the axial rotation motor 512 to the boss block 581 via the belt 56 and pulley 57, causing the boss block 581 to rotate, thereby rotating the operating shaft 41 around the third shaft J3.

[0057] The shaft lifting motor 511 and the shaft rotation motor 512 are positioned on the upper surface 1312a of the top plate 1312 of the housing portion 131, between the operating shaft 41 and the cylindrical portion 132. In other words, the shaft lifting motor 511 and the shaft rotation motor 512 are positioned on the upper surface 1312a side of the top plate 1312 of the housing portion 131, between the operating shaft 41 and the second shaft J2, or between the third shaft J3 and the second shaft J2. In this embodiment, the upper surface 1312a is an example of a fourth surface.

[0058] The belts 52, 56, pulleys 53, 57, lead screw mechanism 54, and spline mechanism 58 are positioned between the upper surface 1311a of the bottom plate 1311 and the lower surface 1312b of the top plate 1312 of the housing portion 131, and between the operating shaft 41 and the second shaft J2. In this embodiment, the upper surface 1311a is an example of a first surface, and the lower surface 1312b is an example of a third surface.

[0059] The cover member 43 is provided to cover the shaft lifting motor 511, the shaft rotation motor 512, and the operating shaft 41, which are provided to protrude from the upper surface 1312a side of the top plate 1312 of the housing portion 131.

[0060] 1.2.3. Inertial Sensor The inertial sensor 8 is a sensor device that houses an inertial sensor element 81 for detecting inertial force and a circuit board 82 on which the inertial sensor element 81 and a processor, interface chip, etc. (not shown) are mounted, in a package. Note that the inertial sensor 8 does not necessarily need to be housed in a package; it may be mounted on the housing 131 in its circuit board 82 form.

[0061] In this embodiment, the inertial sensor element 81 includes a total of six sensor elements: acceleration in the X-axis direction, acceleration in the Y-axis direction, acceleration in the Z-axis direction, angular velocity around the X-axis, angular velocity around the Y-axis, and angular velocity around the Z-axis. In other words, the inertial sensor 8 is an IMU (Inertial Measurement Unit) that detects acceleration in three mutually orthogonal axes and angular velocity around the three axes.

[0062] The inertial sensor element 81 is not limited to an IMU. The inertial sensor element 81 may be an acceleration sensor element that detects acceleration in one to three of the X, Y, and Z axes, an angular velocity sensor element that detects angular velocity around one to three of the X, Y, and Z axes, or a sensor element with a configuration combining these.

[0063] Furthermore, as the inertial sensor element 81, for example, a quartz acceleration sensor element using a quartz oscillator can be used. The type of inertial sensor element 81 can be selected according to the application, and for example, a Si-MEMS (Micro Electro Mechanical Systems) sensor element using silicon (Si) as the material can be used. Furthermore, the inertial sensor 8 may be equipped with a display, memory, etc. Also, the inertial sensor 8 may be configured to wirelessly transmit detected values ​​to an external device.

[0064] The inertial sensor 8 is installed on the second arm 130 and detects at least one of angular velocity and acceleration at the installation position, and outputs a detection signal.

[0065] Vibrations from the second arm 130 can negatively affect the work accuracy of the robot 1. For example, the second arm 130 is subjected to horizontal forces and vibrates due to rotation around the first axis J1 of the first arm 120, rotation around the second axis J2 of the second arm 130, and / or rotation around the third axis J3 of the actuation shaft 41. As a result, the position of the actuation shaft 41 may shift from the target position.

[0066] Furthermore, the second arm 130 is subjected to vertical forces and vibrates due to movement along the third axis J3 of the operating shaft 41, and / or gripping or releasing the workpiece 95 by the hand 42. As a result, the position of the hand 42 may shift from the target position.

[0067] Therefore, when performing work with the hand 42, it is preferable to control the drive of each motor 21, 31, and 51 according to the nature, characteristics, and degree of vibration, so that the hand 42 does not deviate from the target position.

[0068] In this embodiment, due to the circumstances described above, the second arm 130 is equipped with an inertial sensor 8. The detection signal from the inertial sensor 8 is used to drive and control each of the motors 21, 31, 511, and 512 so as to suppress vibration. This type of control is called vibration damping control. The robot 1 in this embodiment is configured to improve the work accuracy of the robot 1 by performing vibration damping control.

[0069] However, depending on how the inertial sensors 8 are arranged, there is a risk that the detection accuracy of the inertial sensors 8 and the basic performance of the robot 1 may be impaired. Therefore, in this embodiment, several measures have been taken to ensure that the detection accuracy of the inertial sensors 8 and the basic performance of the robot 1 are not impaired by the arrangement of the inertial sensors 8, and furthermore, to improve the detection accuracy of the inertial sensors 8 and the basic performance of the robot 1. The following describes the design considerations regarding the placement of the inertial sensor 8.

[0070] 1.2.3.1. Placement of Inertial Sensor 8 As shown in Figures 4A and 4B, the first innovation is that the inertial sensor 8 is positioned on the lower surface 1311b of the bottom plate 1311 of the housing 131, in a position that overlaps with the motor 51 in a plan view. The second innovation is that the inertial sensor 8 is positioned on the lower surface 1311b of the bottom plate 1311 of the housing 131, opposite to the upper surface 1311a. In this embodiment, the lower surface 1311b is an example of a second surface.

[0071] 1.2.3.1.1. Placement in a position that overlaps with motor 51 in a plan view. The inertial sensor 8 is positioned so as to overlap with the motor 51 in a plan view. In other words, the inertial sensor 8 is positioned between the operating axis 41 and the second axis J2. This arrangement has a significant effect on the detection accuracy of the inertial sensor 8 and the basic performance of the robot 1. The motor 51 that overlaps with the inertial sensor 8 in a plan view may be both the axis lifting motor 511 and the axis rotation motor 512, or either one of them.

[0072] Firstly, the inertial sensor 8, which is positioned to overlap the motor 51 in a plan view, can accurately detect vibrations caused by the drive of the work head 40. The motor 51 is positioned adjacent to the work head 40. Therefore, by positioning the inertial sensor 8 so that it overlaps with the motor 51 in a plan view, the inertial sensor 8 can accurately detect vibrations caused by the driving of the work head 40. Thus, the robot 1 can improve its work accuracy by using the detection signal from the inertial sensor 8 to perform vibration damping control.

[0073] Secondly, the inertial sensor 8, positioned to overlap the motor 51 in a plan view, can suppress an increase in the arm length of the second arm 130. In other words, the inertial sensor 8, positioned to overlap the motor 51 in a plan view, can suppress an increase in the inertia (moment of inertia) of the second arm 130 rotating around the second axis J2, thereby preventing a deterioration in the basic performance of the robot 1.

[0074] The inertial sensor 8 is positioned between the operating axis 41 and the second axis J2 in the second arm 130. However, in a plan view, it is positioned in a location that overlaps with the motor 51. This ensures the detection accuracy of the inertial sensor 8 while suppressing an increase in the arm length of the second arm 130. Furthermore, compared to the case where the inertial sensor 8 is positioned between the motor 51 and the operating axis 41, the longitudinal length of the second arm 130, i.e., the arm length, can be shortened.

[0075] Thus, in this embodiment, even if an inertial sensor 8 is provided on the second arm 130, it is possible to suppress an increase in the arm length of the second arm 130 or to shorten the arm length of the second arm 130.

[0076] Furthermore, since the arm length of the second arm 130 can be suppressed, the inertia of the second arm 130 rotating around the second axis J2 can be suppressed. Therefore, this arrangement of inertial sensors 8 can avoid a decrease in the work efficiency of the robot 1 due to a decrease in the operating speed of the second arm 130, or an increase in the power consumption of the robot 1 by increasing the power to prevent a decrease in the operating speed of the second arm 130.

[0077] Furthermore, since the arm length of the second arm 130 can be shortened, the inertia of the second arm 130 rotating around the second axis J2 can be reduced. Therefore, this arrangement of inertial sensors 8 can improve the work efficiency of the robot 1 by increasing the operating speed of the second arm 130, and reduce the power consumption of the robot 1 by reducing the size of the motor 31.

[0078] 1.2.3.1.2. Placement of the housing section 131 on the lower surface 1311b of the bottom plate 1311. The inertial sensor 8 is positioned on the bottom plate 1311 of the housing 131, on the lower surface 1311b opposite the upper surface 1311a. This arrangement has a significant effect on the detection accuracy of the inertial sensor 8 and the basic performance of the robot 1.

[0079] For example, as Comparative Example 1, consider the case where the inertial sensor 8 is placed between the bottom plate 1311 and the top plate 1312 of the housing 131, that is, the case where the inertial sensor 8 is placed inside the housing 131. In Comparative Example 1, it becomes necessary to increase the size of the housing 131 in the height direction at least so that the inertial sensor 8 does not come into contact with components placed inside the housing 131, such as the drive unit 50.

[0080] In contrast, if the inertial sensor 8 is placed on the lower surface 1311b of the bottom plate 1311 of the housing 131, the increase in the height of the housing 131 is suppressed. Therefore, the problem of the robot 1 being unable to be installed on the stand 9 due to the housing 131 becoming larger is avoided. Furthermore, an increase in the inertia of the second arm 130 can suppress the decrease in the operating speed of the second arm 130, which would reduce the work efficiency of the robot 1, and it can also suppress the increase in power consumption of the robot 1, which would occur if the power is increased to prevent the operating speed of the second arm 130 from slowing down.

[0081] Furthermore, as Comparative Example 2, we consider the case where the inertial sensor 8 is placed on the lower surface 1312b of the top plate 1312 of the housing 131, in other words, the case where the inertial sensor 8 and the motor 51 are placed on the same top plate 1312. In Comparative Example 2, the distance between the inertial sensor 8 and the motor 51 becomes small, so the inertial sensor 8 is more susceptible to vibrations caused by the operation of the motor 51 and electrical noise generated by the motor 51, which may lead to a deterioration in detection accuracy.

[0082] In contrast, when the inertial sensor 8 is placed on the lower surface 1311b of the bottom plate 1311 of the housing 131, the distance between the inertial sensor 8 and the motor 51 can be increased. This reduces the influence of vibrations caused by the motor 51's operation and electrical noise generated by the motor 51, thereby suppressing a decrease in the accuracy of the inertial sensor 8.

[0083] Furthermore, as Comparative Example 3, we consider the case where the inertial sensor 8 is placed above the motor 51. In Comparative Example 3, the distance between the inertial sensor 8 and the motor 51 becomes small, so the inertial sensor 8 is more susceptible to vibrations caused by the operation of the motor 51 and electrical noise generated by the motor 51, which may lead to a deterioration in detection accuracy.

[0084] In contrast, when the inertial sensor 8 is placed on the lower surface 1311b of the bottom plate 1311 of the housing 131, the distance between the inertial sensor 8 and the motor 51 can be increased. This reduces the influence of vibrations caused by the motor 51's operation and electrical noise generated by the motor 51, thereby suppressing a decrease in the accuracy of the inertial sensor 8.

[0085] As described above, the arrangement of the inertial sensor 8 is best when it is placed on the lower surface 1311b of the bottom plate 1311 of the housing portion 131, compared to the arrangement examples of the inertial sensor 8 shown in Comparative Examples 1, 2, and 3. However, this does not preclude the arrangement examples of the inertial sensor 8 shown in Comparative Examples 1, 2, and 3, and the inertial sensor 8 may be arranged as shown in Comparative Examples 1, 2, and 3.

[0086] 1.3. Robot Systems Next, the configuration of the robot system 100 will be described based on Figures 1 and 5. Figure 5 is a block diagram of the robot system 100 shown in Figure 1.

[0087] As described above, the robot system 100 includes a robot 1, an inertial sensor 8 for detecting vibrations of the robot 1, and a control device 7 for controlling the robot 1. In this embodiment, the control device 7 is an example of a controller.

[0088] In this embodiment, the control device 7 is separate from the robot 1 and installed next to the robot 1. The control device 7 may be built into the robot 1, for example, in the base 110, or it may be installed in a location away from the robot 1, for example, in a control room provided in a separate building.

[0089] As shown in Figure 5, the control device 7 includes a control unit 71, a storage unit 72, and a communication unit 73. These units are connected to each other so that they can communicate with one another, for example, via a bus. The control unit 71 is composed of, for example, at least one CPU (Central Processing Unit), and reads and executes various programs, such as operation programs, stored in the memory unit 72.

[0090] Signals generated by the control unit 71 are transmitted to each part of the robot 1 via the communication unit 73, and signals from each part of the robot 1 are received by the control unit 71 via the communication unit 73. This allows the robot arm 10 to perform a predetermined task under predetermined conditions.

[0091] Furthermore, the control unit 71 includes a position command generation unit, a motor control unit, and a plurality of motor drivers. The motor control unit performs noise processing, coordinate transformation processing, etc., on the output value of the inertial sensor 8 and calculates the magnitude and direction of the vibration detected by the inertial sensor 8. It then generates a feedback value that cancels out such vibration components and uses this feedback value to control each of the motors 21, 31, 511, and 512 of the robot arm 10.

[0092] Specifically, the position command generation unit calculates the target position of the operating axis 41 based on the processing performed by the robot 1, and generates a trajectory to move the operating axis 41 to the calculated target position. The position command generation unit also calculates the rotation angles of each motor 21, 31, 511, and 512 at predetermined control cycles so that the operating axis 41 moves along the generated trajectory, and outputs the resulting target rotation angles as position commands to the motor control unit.

[0093] The motor control unit receives position commands for motors 21, 31, 511, and 512, as well as detection signals from each encoder. It performs feedback control to ensure that the rotation angles of motors 21, 31, 511, and 512 match the target rotation angles, and outputs control signals to each motor driver. Furthermore, when driving at least some of the motors, the motor control unit also receives detection signals from the inertial sensor element 81. The motor control unit, upon receiving detection signals from the inertial sensor element 81, uses the detection signals from at least some of the encoders and the detection signals from the inertial sensor element 81 to calculate a feedback value that cancels out vibration components, and then performs the feedback control described above.

[0094] Motor drivers are provided for each motor 21, 31, 511, and 512, and operate based on control signals from the motor control unit. Each motor driver has an inverter circuit including a switching element, which converts DC current to AC current using PWM control and supplies AC current to each motor 21, 31, 511, and 512 to drive them.

[0095] For example, to describe the driving of motor 31, the motor control unit receives position commands for motor 31, as well as detection signals from the encoders of each motor 21, 511, and 512, and from the inertial sensor 8. These detection signals are used to calculate a feedback value.

[0096] The motor control unit performs feedback control using a feedback value so that the rotation angle of the motor 31, calculated from the detection signal of the motor 31's encoder, matches the target rotation angle of the motor 31, and outputs a control signal to the motor driver of the motor 31.

[0097] The motor driver of motor 31 drives motor 31 based on the control signal from the motor control unit. By using these feedback values ​​to drive each of the motors 21, 31, 511, and 512 of the robot arm 10, vibration damping control can be performed on the first arm 120, the second arm 130, and the work head 40 based on the values ​​detected by the inertial sensor 8.

[0098] Although only one motor control unit is provided in the control unit 71, the motor control unit is not limited to this, and multiple motor control units may be provided. If multiple motor control units are provided, each motor control unit may correspond to one of the motors 21, 31, 511, and 512. Furthermore, the motor control unit when driving motor 31 may be configured so that the detection signal from the encoder of motor 21 is not input. In that case, the motor control unit calculates a feedback value using the detection signals from the encoder of motor 31 and the inertial sensor 8.

[0099] However, the configuration is not limited to this, and the control unit 71 can be configured to perform vibration damping control on one or any two or more combinations of the first arm 120, the second arm 130, and the work head 40 based on the detected value of the inertial sensor 8.

[0100] For example, the control unit 71 may be configured to perform vibration damping control only on the first arm 120 based on the detected value of the inertial sensor 8. In other words, the feedback value may be used only to drive the motor 21.

[0101] Furthermore, the control unit 71 may be configured to perform vibration damping control only on the second arm 130 based on the detected value of the inertial sensor 8. In other words, the feedback value may be used to drive only the motor 31.

[0102] Furthermore, the control unit 71 may be configured to perform vibration damping control only on the work head 40 based on the detected value of the inertial sensor 8. That is, the feedback value may be used to drive only the shaft lifting motor 511 and the shaft rotation motor 512 of the drive unit 50. Also, when performing vibration damping control on the work head 40, the feedback value may be used to drive only one of the shaft lifting motor 511 and the shaft rotation motor 512.

[0103] Furthermore, the control unit 71 may be configured to perform vibration damping control only on the first arm 120 and the second arm 130 based on the detected values ​​of the inertial sensor 8. In other words, the feedback values ​​may be used only to drive the motor 21 and the motor 31.

[0104] Furthermore, the control unit 71 may be configured to perform vibration damping control only on the first arm 120 and the work head 40 based on the detected value of the inertial sensor 8. In other words, the feedback value may be used only to drive the motor 21, the axial lifting motor 511, and the axial rotation motor 512.

[0105] Furthermore, the control unit 71 may be configured to perform vibration damping control only on the second arm 130 and the work head 40 based on the detected value of the inertial sensor 8. In other words, the feedback value may be used only to drive the motor 31, the axial lifting motor 511, and the axial rotation motor 512.

[0106] By performing vibration damping control as described above, robot 1 can improve the positional accuracy of its work and perform high-precision tasks.

[0107] The memory unit 72 stores various programs and other data executed by the control unit 71. Examples of the memory unit 72 include configurations that include volatile memory such as RAM (Random Access Memory), non-volatile memory such as ROM (Read Only Memory), and removable external storage devices.

[0108] The communication unit 73 transmits and receives signals between the robot 1 and the control device 7 using an external interface such as a wired LAN (Local Area Network) or wireless LAN. In this case, communication may be performed via a server (not shown) or via a network such as the Internet.

[0109] As described above, the robot 1 and robot system 100 of this embodiment provide the following advantages. The robot 1 of this embodiment comprises a base 110, a first arm 120 whose longitudinal end overlaps the base 110 in a plan view, a joint 25 provided on one end of the first arm 120 and serving as a first joint that holds the first arm 120 so as to be rotatable around a first axis J1 relative to the base 110, a second arm 130 whose longitudinal end overlaps the other longitudinal end of the first arm 120 in a plan view, a joint 35 provided on one end of the second arm 130 and serving as a second joint that holds the second arm 130 so as to be rotatable around a second axis J2 parallel to the first axis J1 relative to the first arm 120, and the longitudinal direction of the second arm 130 The second arm 130 comprises an operating shaft 41 provided on the other end of the arm, and a housing portion 131 having a bottom plate 1311 as a first plate portion, a motor 51 positioned between the operating shaft 41 and the second axis J2 on the upper surface 1311a side as the first surface of the bottom plate 1311, which rotates the operating shaft 41 around a third axis J3 parallel to the second axis J2, or moves along the third axis J3, and an inertial sensor 8 positioned on the lower surface 1311b side as the second surface opposite the upper surface 1311a of the bottom plate 1311, in a position that overlaps with the motor 51 in a plan view, which detects at least one of angular velocity and acceleration.

[0110] Thus, in this embodiment, the robot 1 has the inertial sensor 8 positioned on the lower surface 1311b side opposite to the upper surface 1311a of the base plate 1311. Therefore, in this embodiment, the robot 1 can suppress an increase in the arm length of the second arm 130 and suppress an increase in the inertia of the second arm 130 rotating around the second axis J2. Furthermore, since the housing portion 131 is suppressed to become larger in the height direction, it is possible to prevent the robot 1 from being installed on the stand 9 and to prevent an increase in the inertia of the second arm 130.

[0111] In the robot 1 of this embodiment, the motor 51 includes an axial lifting motor 511 as a first motor and an axial rotation motor 512 as a second motor, and the axial lifting motor 511 and the axial rotation motor 512 are provided adjacent to each other along the longitudinal direction of the second arm 130.

[0112] In this way, by providing the axial lifting motor 511 and the axial rotation motor 512 adjacent to each other along the longitudinal direction of the second arm 130, the arm length of the second arm 130 becomes longer. However, the robot 1 of this embodiment can suppress the arm length of the second arm 130 from becoming unnecessarily long.

[0113] In the robot 1 of this embodiment, the housing portion 131 has a bottom plate 1311 which is a first plate portion and a top plate 1312 which is a second plate portion that overlaps with it, the motor 51 is fixed to the top plate 1312 and the inertial sensor 8 is fixed to the bottom plate 1311.

[0114] In this way, the motor 51 is fixed to the top plate 1312 and the inertial sensor 8 is fixed to the bottom plate 1311, so vibrations and noise caused by the operation of the motor 51 are less likely to be transmitted to the bottom plate 1311. Therefore, the detection accuracy of the inertial sensor 8 can be improved compared to when the motor 51 and the inertial sensor 8 are fixed to the same top plate 1312 or bottom plate 1311.

[0115] In the robot 1 of this embodiment, the top plate 1312, which is the second plate portion, has a bottom surface 1312b, which is the third surface, opposite to the top surface 1311a, which is the first surface of the bottom plate 1311, which is the first surface, and a top surface 1312a, which is the fourth surface, opposite to the bottom surface 1312b. The motor 51 is fixed to the top surface 1312a, and the inertial sensor 8 is positioned so as to overlap with the motor 51 in a plan view.

[0116] Thus, the motor 51 is fixed to the upper surface 1312a of the top plate 1312, and the inertial sensor 8 is positioned so as to overlap with the motor 51 in a plan view. Therefore, it is possible to suppress an increase in the arm length of the second arm 130, and thus suppress an increase in the inertia of the second arm 130 as it rotates around the second axis J2.

[0117] The robot system 100 of this embodiment comprises the robot 1 described above and a control device 7 which acts as a controller for controlling the robot 1. Therefore, it is possible to realize a robot system 100 that has high operational precision and high industrial utility.

[0118] 2. Embodiment 2 Figure 6A is a partial cross-sectional view of the robot 1 according to Embodiment 2. Figure 6B is a side view of the robot 1 according to Embodiment 2 as seen from the negative X-axis side. Figure 6C is a plan view of the robot 1 according to Embodiment 2 as seen from the negative Z-axis side.

[0119] Embodiment 2 shows another arrangement example of the inertial sensor 8 shown in Embodiment 1. In the following description, the same reference numerals are used for components identical to those in Embodiment 1, and redundant explanations are omitted.

[0120] As shown in Figures 6A to 6C, the inertial sensor 8 is positioned so as to overlap with the motor 51 in a plan view. In the robot 1 of Embodiment 2, the axial lifting motor 511 and the axial rotation motor 512, which constitute the motor 51, are positioned adjacent to each other along the shorter direction of the second arm 130.

[0121] In Embodiment 2, the axial lifting motor 511 and the axial rotation motor 512 are provided adjacent to each other along the shorter direction of the second arm 130, so the arm length of the second arm 130 can be made shorter than in Embodiment 1. Therefore, the inertia of the second arm 130 rotating around the second axis J2 can be made smaller than in Embodiment 1. Note that the motor 51 that overlaps with the inertial sensor 8 in a plan view may be both the axial lifting motor 511 and the axial rotation motor 512, or either one of them.

[0122] The inertial sensor 8 is positioned between the actuation shaft 41 and the second axis J2 in the second arm 130. However, in a plan view, it is positioned in a location that overlaps with the motor 51, thus preventing the arm length of the second arm 130 from becoming excessively long. Furthermore, compared to the case where the inertial sensor 8 is positioned between the motor 51 and the actuation shaft 41, the length of the second arm 130 in the shorter direction, i.e., the arm length, can be shortened.

[0123] Thus, in this embodiment, even if an inertial sensor 8 is provided on the second arm 130, it is possible to suppress an increase in the arm length of the second arm 130 or to shorten the arm length of the second arm 130.

[0124] In Embodiment 2, since the arm length of the second arm 130 can be suppressed, the inertia of the second arm 130 rotating around the second axis J can be suppressed. Therefore, this arrangement of the inertial sensor 8 can avoid a decrease in work efficiency due to a decrease in the operating speed of the second arm 130, or an increase in power consumption due to increasing the power to prevent a decrease in the operating speed of the second arm 130.

[0125] Furthermore, in Embodiment 2, the arm length of the second arm 130 can be shortened, thereby reducing the inertia of the second arm 130 as it rotates around the second axis J2. Therefore, this arrangement of the inertial sensor 8 can increase the operating speed of the second arm 130, improve work efficiency, and reduce the size of the motor 31, thereby reducing power consumption.

[0126] As shown in Figures 6A to 6C, the inertial sensor 8 of Embodiment 2 is positioned on the lower surface 1311b opposite the upper surface 1311a of the housing portion 131, similar to Embodiment 1. This arrangement, like that of Embodiment 1, provides excellent results.

[0127] Furthermore, in Embodiment 2, similar to Embodiment 1, the motor 51 is positioned adjacent to the work head 40. Therefore, the inertial sensor 8, which is positioned to overlap the motor 51 in a plan view, can accurately detect vibrations caused by the driving of the work head 40. Thus, by using the detection signal from such inertial sensor 8 to perform vibration damping control, the work accuracy of the robot 1 can be improved.

[0128] As shown in Figure 6C, a group of connectors 6 is provided on the lower surface 1311b of the second arm 130 at a position overlapping with the cylindrical portion 132. The group of connectors 6 consists of, for example, power lines for driving the hand 42, various signal lines, and connectors 61, 62, 63, 64, and 65 for connecting various pipes.

[0129] As described above, the robot 1 of Embodiment 2 provides the following effects in addition to the effects of Embodiment 1. In the robot 1 of this embodiment, the motor 51 includes an axial lifting motor 511 as a first motor and an axial rotation motor 512 as a second motor, and the axial lifting motor 511 and the axial rotation motor 512 are provided adjacent to each other along the short side of the second arm 130.

[0130] In this way, by providing the axial lifting motor 511 and the axial rotation motor 512 adjacent to each other along the shorter direction of the second arm 130, the arm length of the second arm 130 can be shortened. Furthermore, even if an inertial sensor 8 is provided on the second arm 130, it is possible to suppress an increase in the arm length of the second arm 130.

[0131] 3. Embodiment 3 Figure 7A is a partial cross-sectional view of the robot 1 according to Embodiment 3. Figure 7B is a plan view of the robot 1 according to Embodiment 3 as seen from the negative Z-axis side.

[0132] Embodiment 3 shows yet another arrangement example of the inertial sensor 8 shown in Embodiments 1 and 2. In the following description, the same reference numerals are used for components identical to those in Embodiments 1 and 2, and redundant explanations are omitted.

[0133] As shown in Figures 7A and 7B, in Embodiment 3, the inertial sensor 8 is provided on the lower surface 1311b of the housing portion 131, in a position that overlaps with the cylindrical portion 132 in a plan view. In other words, the inertial sensor 8 is positioned on the second axis J2 side of the motor 51 in a plan view.

[0134] As described above, the inertial sensor 8 of Embodiment 3 is positioned on the second axis J2 side of the motor 51 in a plan view and overlaps with the cylindrical portion 132, so that vibrations of the cylindrical portion 132, especially torsional vibrations, can be detected with high accuracy. Furthermore, since the distance between the inertial sensor 8 and the motor 51 can be increased, the influence of vibrations caused by the operation of the motor 51 and electrical noise generated by the motor 51 is reduced, and a decrease in the accuracy of the inertial sensor 8 can be suppressed.

[0135] As described above, the robot 1 of Embodiment 3 provides the following effects in addition to the effects of Embodiment 1 and / or Embodiment 2. The robot 1 of this embodiment includes a base 110, a first arm 120 whose longitudinal end overlaps the base 110 in a plan view, a joint 25 provided on one end of the first arm 120 and serving as a first joint that holds the first arm 120 so as to be rotatable around a first axis J1 relative to the base 110, a second arm 130 whose longitudinal end overlaps the other longitudinal end of the first arm 120 in a plan view, a joint 35 provided on one end of the second arm 130 and serving as a second joint that holds the second arm 130 so as to be rotatable around a second axis J2 parallel to the first axis J1 relative to the first arm 120, and the other longitudinal end of the second arm 130 The second arm 130 comprises an operating shaft 41 provided at one end, a housing portion 131 having a bottom plate 1311 as a first plate portion, a motor 51 positioned between the operating shaft 41 and the second axis J2 on the upper surface 1311a side as the first surface of the bottom plate 1311, and rotating the operating shaft 41 around a third axis J3 parallel to the second axis J2, or moving it along the third axis J3, and an inertial sensor 8 positioned on the lower surface 1311b side as the second surface opposite the upper surface 1311a of the bottom plate 1311, in a plan view, closer to the second axis J2 than the motor 51, and detecting at least one of angular velocity and acceleration.

[0136] Thus, in this embodiment, the robot 1 has the inertial sensor 8 positioned on the second axis J2 side of the motor 51 in a plan view. Therefore, the inertial sensor 8 can accurately detect vibrations of the cylindrical portion 132, particularly torsional vibrations.

[0137] In the robot 1 of this embodiment, the housing portion 131 has a cylindrical portion 132 surrounding the second axis J2, and the inertial sensor 8 is provided in a position that overlaps with the cylindrical portion 132 in a plan view. Therefore, the inertial sensor 8 can accurately detect vibrations of the cylindrical portion 132, particularly torsional vibrations.

[0138] Although embodiments of robot 1 and robot system 100 have been described above, the present invention is not limited to these. Furthermore, each part of robot system 100 can be replaced with any structure capable of performing similar functions. In addition, arbitrary structures may be added to robot system 100. Moreover, the present invention may be a combination of some of the features of each embodiment. [Explanation of symbols]

[0139] 1...Robot, 6...Connector group, 61, 62, 63, 64, 65...Connectors, 7...Control device, 8...Inertial sensor, 81...Inertial sensor element, 82...Circuit board, 9...Stand, 91...Top plate, 911...Top surface, 912...Bottom surface, 913, 914...Through hole, 92...Workbench, 93...Legs, 95...Workpiece, 10...Robot arm, 11...Main body, 12...Fittings, 13...Base plate, 20...Drive unit 21...Motor, 22...Belt, 23...Pulley, 25...Joint, 26...Reduction gear, 261...Wave generator, 262...Flex spline, 263...Circular spline, 27...Flange, 28...Hollow tube, 30...Drive unit, 31...Motor, 32...Belt, 33...Pulley, 35...Joint, 36...Reduction gear, 361...Wave generator, 362...Flex spline, 363...Circular spline, 37...Flange, 38...Hollow tube, 40...Working head, 41...Operating shaft, 42...Hand, 43...Cover member, 50...Drive unit, 51...Motor, 511...Axis lifting motor, 512...Axis rotation motor, 52...Belt, 53...Pulley, 54...Lead screw mechanism, 541...Female screw block, 56...Belt, 57...Pulley, 58...Spline machine Structure, 581...Boss block, 71...Control unit, 72...Memory unit, 73...Communication unit, 100...Robot system, 110...Base, 120...First arm, 121...Cover, 130...Second arm, 131...Housing unit, 1311...Bottom plate, 1311a...Top surface, 1311b...Bottom surface, 1312...Top plate, 1312a...Top surface, 1312b...Bottom surface, 132...Cylinder unit, J1...First axis, J2...Second axis, J3...Third axis.

Claims

1. Base and, In a plan view, one end in the longitudinal direction of the first arm overlaps with the base, A first joint is provided on one end of the first arm and holds the first arm so as to be rotatable around a first axis relative to the base, In a plan view, the second arm has one end in the longitudinal direction that overlaps with the other end in the longitudinal direction of the first arm, A second joint is provided on one end of the second arm, and holds the second arm so that it can rotate around a second axis parallel to the first axis relative to the first arm, The second arm comprises a shaft provided on the other end in the longitudinal direction of the second arm, The second arm is, A housing portion having a first plate portion, On the first surface side of the first plate portion, a motor is positioned between the shaft and the second axis, and rotates the shaft around a third axis parallel to the second axis, or moves it along the third axis. The first plate portion has an inertial sensor that is positioned on the second surface opposite to the first surface, in a plan view, at a position that overlaps with the motor, or at a position closer to the second axis than the motor, and which detects at least one of angular velocity and acceleration. robot.

2. The motor includes a first motor and a second motor, The first motor and the second motor are provided adjacent to each other along the longitudinal direction of the second arm, The robot according to claim 1.

3. The motor includes a first motor and a second motor, The first motor and the second motor are provided adjacent to each other along the shorter direction of the second arm. The robot according to claim 1.

4. The housing portion has a second plate portion that overlaps with the first plate portion, The motor is fixed to the second plate portion, The inertial sensor is fixed to the first plate portion. The robot according to claim 1.

5. The second plate portion has a third surface facing the first surface of the first plate portion, and a fourth surface opposite to the third surface. The motor is fixed to the fourth surface, The inertial sensor is positioned in a location that overlaps with the motor in a plan view. The robot according to claim 4.

6. The housing portion has a cylindrical portion surrounding the second shaft, The inertial sensor is positioned in a location that overlaps with the cylindrical portion in a plan view. The robot according to claim 1.

7. A robot according to any one of claims 1 to 6, The system includes a controller for controlling the robot, Robot system.

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