Robot and robot system

Abstract

The present invention provides a robot comprising an inertial sensor. The present invention also provides a robot system.　A robot 1 comprises: a base 110; a first arm 120 that overlaps the base 110; a joint 25 that holds the first arm 120 such that the first arm 120 can be rotated about a first shaft J1; a second arm 130 that overlaps the first arm 120; a joint 35 that is provided to the second arm 130 and that holds the second arm 130 such that second arm 130 can be rotated about a second shaft J2; and an operational shaft 41 that is provided to the second arm 130, wherein the second arm 130 includes a housing 131 that has a bottom plate 1311, a motor 51 that is disposed between the operational shaft 41 and the second shaft J2 on the upper surface 1311a side of the bottom plate 1311 and that rotates the operational shaft 41 about a third shaft J3, and an inertial sensor 8 that is disposed on the lower surface 1311b side of the bottom plate 1311 so as to overlap the motor 51 in plan view and that detects at least one of angular velocity and acceleration.

Description

Robots and Robot Systems

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

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

[0003] Furthermore, the SCARA robot described in Patent Document 1 is equipped with a gyro sensor module equipped with an angular velocity sensor on the second arm, and uses information on the angular velocity detected by the angular velocity sensor to control the driving of the first motor unit and / or the second motor unit so as to suppress horizontal vibrations caused by driving the second arm.

[0004] In the SCARA 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.

[0005] JP 2013-111665 A

[0006] In a SCARA robot equipped with an inertial sensor module like this, space is required on the second arm to place the inertial sensor module, so the challenge is how to place the inertial sensor module while ensuring the detection accuracy of the inertial sensor and the basic performance of the SCARA robot.

[0007] The robot of the present invention includes a base, a first arm having one end side in a longitudinal direction overlapping with the base in a plan view, a first joint provided at the one end side of the first arm and holding the first arm rotatably around a first axis relative to the base, a second arm having one end side in a longitudinal direction overlapping with the other end side of the first arm in a plan view, a second joint provided at the one end side of the second arm and holding the second arm rotatably around a second axis parallel to the first axis relative to the first arm, and a second joint provided at the other end side of the second arm in the longitudinal direction. and a shaft provided on the second arm, the second arm having a housing portion with a first plate portion, a motor arranged on a first surface side of the first plate portion between the shaft and the second axis, and rotating the shaft around a third axis parallel to the second axis or moving the shaft along the third axis, and an inertial sensor arranged on a second surface side opposite the first surface of the first plate portion at a position overlapping with the motor in a plan view 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 includes the robot and a controller that controls the robot.

[0009] 1 is an overall perspective view of a robot system including a robot according to this embodiment; 2 is a partially enlarged perspective view of FIG. 1; 3 is a side view of the robot of FIG. 1; 4 is a partial cross-sectional view of the robot of FIG. 3; 5 is a plan view of the robot of FIG. 3, viewed from the negative side in the Z-axis direction; 6 is a block diagram of the robot system of FIG. 1; 7 is a partial cross-sectional view of a robot according to a second embodiment; 8 is a side view of the robot according to the second embodiment, viewed from the negative side in the X-axis direction; 9 is a plan view of the robot according to the second embodiment, viewed from the negative side in the Z-axis direction; 10 is a partial cross-sectional view of a robot according to a third embodiment; and 11 is a plan view of the robot according to the third embodiment, viewed from the negative side in the Z-axis direction.

[0010] In the embodiments of the present invention, components shown in each drawing may be shown with different scales for easier viewing. The drawings may show three mutually orthogonal axes, namely, an X-axis, a Y-axis, and a Z-axis. The X-axis and the Y-axis are arranged so that a plane including the X-axis and the Y-axis is horizontal, and the Z-axis is arranged so that the tip of the arrow points vertically upward.

[0011] In the following description, the tip end of each of the three arrows may be referred to as the "plus side," and the base end of each arrow may be referred to as the "minus side." The direction parallel to the X-axis may be referred to as the "X-axis direction," the direction parallel to the Y-axis may be referred to as the "Y-axis direction," and the direction parallel to the Z-axis may be referred to as the "Z-axis direction."

[0012] In the following, "planar view" refers to viewing an object from the positive side of the Z axis or the negative side of the Z axis. The positive side of the Z axis is sometimes referred to as "above," and the negative side of the Z axis is sometimes referred to as "below."

[0013] Furthermore, the term "top surface" of a certain configuration refers to the surface of the configuration on the positive side in the Z-axis direction, for example, "top surface of a plate portion" refers to the surface of the plate portion on the positive side in the Z-axis direction. Furthermore, the term "bottom surface" of a certain configuration refers to the surface of the configuration on the negative side in the Z-axis direction, for example, "bottom surface of a plate portion" refers to the surface of the plate portion on the negative side in the Z-axis direction.

[0014] Three preferred embodiments of the robot 1 and robot system 100 of the present invention will be described below.

[0015] 1. Embodiment 1 1.1 Overall Configuration of Robot and Robot System Fig. 1 is an overall perspective view of a robot system 100 including a robot 1 according to embodiment 1. Fig. 2 is a partially enlarged perspective view of Fig. 1.

[0016] The robot system 100 is an industrial robot that automates various tasks such as assembly in factories, etc., in place of humans. The robot system 100 includes a robot 1, an inertial sensor 8 that detects vibrations 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 moves horizontally. In this embodiment, an example of the robot 1 will be described, in which the robot 1 is a ceiling-suspended SCARA robot that is suspended from the ceiling of a base 9. However, the robot 1 may also be a SCARA robot that is installed on the floor or a workbench.

[0018] The pedestal 9 is installed on a production line in a factory that manufactures precision equipment such as mobile phones, smartphones, and tablet devices, and the robot 1 is controlled by the control device 7 and performs tasks such as gripping, transporting, processing, and assembling on a workpiece 95 such as a precision equipment or part placed on a workbench 92. The installation surface of the ceiling-suspended robot 1 is not limited to the top plate 91 of the pedestal 9. The installation surface of the ceiling-suspended robot 1 may be, for example, the ceiling or wall of a workroom, a beam, a pillar, a brace, other structural members, a hoist rail, etc. The ceiling-suspended robot 1 also includes wall-mounted and wall-attached robots that use a side wall as the installation surface.

[0019] The stand 9 has a top plate 91, a work table 92, and frame-shaped legs 93. The 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 provided so that the surface on which the robot 1 is placed is horizontal.

[0020] The top plate 91 has through holes 913 and 914 that penetrate through the thickness thereof. The 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, which will be described later, etc. The through hole 914 is a hole in which the robot 1 is installed, and the base 110 is inserted into the through hole 914.

[0021] 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, one end side of the first arm 120 in the longitudinal direction is provided so as to overlap with the base 110 via a joint unit 25. The joint unit 25 is provided on one end side of the first arm 120 in the longitudinal direction and holds the first arm 120 rotatably about a first axis J1 with respect to the base 110. In this embodiment, the first axis J1 is an imaginary axis extending along the vertical direction and indicates the axis of rotation of the first arm 120. In this embodiment, the joint unit 25 is an example of a first joint.

[0023] In a plan view, one longitudinal end of the second arm 130 overlaps the other longitudinal end of the first arm 120 via a joint 35. The joint 35 is provided at one longitudinal end of the second arm 130 and holds the second arm 130 rotatably about a second axis J2 parallel to the first axis J1 relative to the first arm 120. In this embodiment, the second axis J2 is an imaginary axis extending vertically and represents the axis of rotation of the second arm 130. The second axis J2 and the first axis J1 are parallel to each other. In this embodiment, the joint 35 is an example of a second joint.

[0024] The working head 40 is provided on the other longitudinal end side of the second arm 130. The working head 40 includes 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 of the second arm 130 and sends a detection signal consisting of swing 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] As described above, the robot system 100 of this embodiment can improve vibration damping performance by mounting the inertial sensor 8 on the robot 1. Therefore, it is possible to realize a robot 1 and a robot system 100 that are capable of servo control with excellent speed, accuracy, and / or energy efficiency. Furthermore, in this embodiment, by devising the placement of the inertial sensor 8, it is possible to achieve both accuracy of vibration data and workability of the robot 1. The placement of the inertial sensor 8 will be described later in Section 1.2.3.1.

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

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

[0029] The base 110 is located at the top of the robot 1 and is attached to the top plate 91 of the stand 9. The base 110 has a main body 11, a plate-shaped base plate 13 provided at the bottom of the main body 11, and a drive unit 20 provided inside the main body 11 and configured to rotate the first arm 120 around the first axis J1.

[0030] The main body 11 and the base plate 13 form a housing that houses a part of the drive unit 20. The base 110 is installed on the top plate 91 by fixing the base plate 13 together with the metal fittings 12 to the upper surface 911 and / or the lower surface 912 of the top plate 91 with fixing members such as bolts, screws, and pins. With the base 110 installed on the top plate 91, the robot 1 functions as a ceiling-suspended SCARA robot.

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

[0032] The joint portion 25 has a reducer 26 and a flange 27. In this embodiment, the reducer 26 is a wave gear reducer. However, the reducer 26 may be another type of reducer, such as a planetary gear reducer. One side of the flange 27 is fixed to the output shaft of the reducer 26, and the other side is fixed to the first arm 120.

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

[0034] Cables such as power lines and various signal lines connected to the drive unit 30, drive unit 50, work head 40, inertial sensor 8, etc., which will be described later, and / or other pipes are inserted into 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 One end of the first arm 120 that extends horizontally is cantilevered to the base 110 via a joint 25 .

[0037] The first arm 120 rotates around a first axis J1, which is a rotation axis, and moves in a horizontal direction. A drive unit 30 is provided on the first arm 120. The drive unit 30 drives the second arm 130 to rotate around a second axis J2.

[0038] The drive unit 30 has a motor 31, a belt 32, a pulley 33, and a joint unit 35. The motor 31 is disposed in the longitudinal center portion of the first arm 120, in other words, near the middle between the first axis J1 and the second axis J2. Rotation of the motor 31 is transmitted to the joint unit 35 via the belt 32 and the pulley 33. The motor 31 has a portion that protrudes from the housing of the first arm 120 toward the positive side in the Z axis direction. The cover 121 covers the protruding portion of the motor 31.

[0039] The joint portion 35 has a reducer 36 and a flange 37. In this embodiment, the reducer 36 is a wave gear reducer. However, the reducer 36 may be another type of reducer, such as a planetary gear reducer.

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

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

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

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

[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 to each other, but are offset from each other in the horizontal direction. In other words, the first axis J1 and the second axis J2 are spaced a predetermined distance apart in the horizontal direction. This allows the robot arm 10 to have a wide range of motion.

[0045] The second arm 130 has a housing portion 131 and a tubular portion 132. The tubular portion 132 is provided in the second arm 130 between the housing portion 131 and the flange 37. One side of the tubular portion 132 is fixed to the flange 37, and the other side is connected to the housing portion 131. In other words, the tubular portion 132 functions as a joint that connects the flange 37 and the housing portion 131. The tubular portion 132 is provided such that a cylindrical portion surrounds the second axis J2, and the length along the second axis J2 is provided such that the second arm 130 can rotate 360° relative to the first arm 120, for example. For example, the length of the working head 40 from the upper surface 1312a of the top plate 1312 of the housing 131 to the upper end of the working head 40 is shorter than the axial distance of the third axis J3 from the upper surface 1312a of the top plate 1312 of the housing 131 to the lower surface of the bottom plate of the first arm 120. This allows the second arm 130 to pass below the first arm 120 without interfering with the working head 40, even when the actuating shaft 41 is raised to its highest position. In other words, the second arm 130 can rotate 360° relative to the first arm 120, regardless of the vertical position of the working 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 a floor or a workbench, the second arm 130 is provided above the first arm 120, so the cylindrical portion 132 is not required.

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

[0047] The work head 40 includes an actuating shaft 41 and a hand 42. The longitudinal direction of the actuating shaft 41 extends along a third axis J3, and the actuating shaft 41 is driven by a drive unit 50 to slide vertically along the third axis J3 and / or rotate about the third axis J3. In this embodiment, the third axis J3 is an imaginary axis extending vertically and represents the axis of rotation of the actuating shaft 41. The third axis J3, the first axis J1, and the second axis J2 are parallel to each other.

[0048] The actuating 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 actuating shaft 41 and connected to the hand 42. Note that the actuating shaft 41 is not limited to the hollow shaft type. Cables and the like connected to the hand 42 may be connected via the outside of the actuating shaft 41.

[0049] The hand 42 is an end effector, and is controlled by the control device 7 to perform operations such as gripping, transporting, processing, and assembling a workpiece 95 such as a precision device or part placed on the work table 92 .

[0050] The hand 42 is detachably attached to the lower end of the operating shaft 41. An end effector suited to the task is selected from a variety of end effectors for the hand 42. Examples of end effectors include a gripper, a suction end effector, a purpose-specific end effector, and a robot hand.

[0051] The drive unit 50 has a shaft lifting mechanism that slides the operating shaft 41 up and down, and a shaft rotating mechanism that rotates the operating shaft 41 around the third axis J3.

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

[0053] The shaft lifting mechanism is composed of a shaft lifting motor 511, a belt 52, a pulley 53, and a lead screw mechanism 54. The lead screw mechanism 54 is composed 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 rotatably supported on the top plate 1312 of the housing part 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, thereby moving the operating shaft 41 along the third axis J3, i.e., upward or downward.

[0055] The shaft rotation mechanism is composed of a shaft rotation motor 512, a belt 56, a pulley 57, and a spline mechanism 58. The spline mechanism 58 is composed 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 rotatably supported on the bottom plate 1311 of the housing 131. The spline mechanism 58 supports the operating shaft 41 so that it can slide freely in the vertical direction.

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

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

[0058] The belts 52, 56, the pulleys 53, 57, the lead screw mechanism 54, and the spline mechanism 58 are disposed between the operating shaft 41 and the second axis J2, between an upper surface 1311a of the bottom plate 1311 and a lower surface 1312b of the top plate 1312 of the housing 131. In the present 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 rotating motor 512 , and the operating shaft 41 that are provided to protrude from the upper surface 1312 a side of the top plate 1312 of the housing part 131 .

[0060] The inertial sensor 8 is a sensor device that houses, in a package, an inertial sensor element 81 that detects inertial force and a substrate 82 on which the inertial sensor element 81 and a processor and interface chip (not shown) are mounted. Note that the inertial sensor 8 does not necessarily have to be housed in a package, and may be attached to the housing 131 in the form of the substrate 82.

[0061] In this embodiment, the inertial sensor element 81 includes six types of sensor elements, namely, 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 axis directions and angular velocity around 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 about one to three axes selected from the X-axis, Y-axis, and Z-axis, an angular velocity sensor element that detects angular velocity about one to three axes selected from the X-axis, Y-axis, and Z-axis, or a sensor element having a configuration that combines these.

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

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

[0065] Vibration of the second arm 130 may adversely affect the work accuracy of the robot 1. For example, the second arm 130 receives horizontal forces and vibrates due to the rotation of the first arm 120 about the first axis J1, the rotation of the second arm 130 about the second axis J2, and / or the rotation of the actuating axis 41 about the third axis J3. As a result, the position of the actuating axis 41 may deviate from the target position.

[0066] Furthermore, the second arm 130 receives a force in the vertical direction and vibrates due to movement of the actuation shaft 41 along the third axis J3 and / or gripping or releasing of the workpiece 95 by the hand 42. As a result, the position of the hand 42 may deviate from the target position.

[0067] Therefore, when performing work using the hand 42, it is preferable to control the drive of each of the motors 21, 31, 51 in accordance with the content, characteristics, degree, etc. of the vibration so that the hand 42 does not deviate from the target position.

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

[0069] However, depending on how the inertial sensor 8 is arranged, there is a risk that the detection accuracy of the inertial sensor 8 and the basic performance of the robot 1 may be impaired. Therefore, in this embodiment, several measures have been taken to prevent the arrangement of the inertial sensor 8 from impairing the detection accuracy of the inertial sensor 8 and the basic performance of the robot 1, and to improve the detection accuracy of the inertial sensor 8 and the basic performance of the robot 1. The measures taken regarding the arrangement of the inertial sensor 8 will be described below.

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

[0071] 1.2.3.1.1. Placement at a position overlapping the motor 51 in a plan view The inertial sensor 8 is provided at a position overlapping the motor 51 in a plan view. In other words, the inertial sensor 8 is placed between the actuation shaft 41 and the second axis J2. This placement has a very excellent effect on the detection accuracy of the inertial sensor 8 and the basic performance of the robot 1. Note that the motor 51 overlapping the inertial sensor 8 in a plan view may be both the shaft lifting motor 511 and the shaft rotating motor 512, or either one of them.

[0072] First, the inertial sensor 8, which is provided at a position overlapping the motor 51 in a plan view, can accurately detect vibrations caused by driving the work head 40. The motor 51 is provided at a position adjacent to the work head 40. Therefore, by providing the inertial sensor 8 at a position overlapping the motor 51 in a plan view, the inertial sensor 8 can accurately detect vibrations caused by driving the work head 40. Therefore, the robot 1 can improve work accuracy by performing vibration suppression control using the detection signal of this inertial sensor 8.

[0073] Second, the inertial sensor 8 provided at a position overlapping the motor 51 in a plan view can prevent the arm length of the second arm 130 from increasing. In other words, the inertial sensor 8 provided at a position overlapping the motor 51 in a plan view can prevent an increase in the moment of inertia of the second arm 130 rotating around the second axis J2, thereby preventing the basic performance of the robot 1 from being impaired.

[0074] The inertial sensor 8 is disposed on the second arm 130 between the actuation shaft 41 and the second axis J2, but is disposed at a position overlapping with the motor 51 in a plan view, and therefore it is possible to prevent the arm length of the second arm 130 from increasing while ensuring the detection accuracy of the inertial sensor 8. Furthermore, compared to when the inertial sensor 8 is disposed between the motor 51 and the actuation shaft 41, it is possible to shorten the length of the second arm 130 in the longitudinal direction, i.e., the arm length.

[0075] In this way, in this embodiment, even if the inertial sensor 8 is provided on the second arm 130, it is possible to prevent the arm length of the second arm 130 from becoming longer or to shorten the arm length of the second arm 130.

[0076] Furthermore, since the arm length of the second arm 130 can be prevented from increasing, the inertia of the second arm 130 rotating about the second axis J2 can be prevented from increasing. Therefore, such an arrangement of the inertia sensor 8 can avoid a decrease in the operating speed of the second arm 130, which would reduce the work efficiency of the robot 1, and an increase in power consumption of the robot 1 due to an increase in 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 about the second axis J2 can be reduced. Therefore, such an arrangement of the inertia sensor 8 can increase the operating speed of the second arm 130, thereby improving the work efficiency of the robot 1, and can reduce the power consumption of the robot 1 by reducing the size of the motor 31.

[0078] The inertial sensor 8 is placed on the lower surface 1311b of the bottom plate 1311 of the housing 131. The inertial sensor 8 is placed on the lower surface 1311b, opposite the upper surface 1311a, of the bottom plate 1311 of the housing 131. This placement has a very excellent 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 a case where the inertial sensor 8 is disposed between the bottom plate 1311 and the top plate 1312 of the housing part 131, that is, a case where the inertial sensor 8 is disposed inside the housing part 131. In Comparative Example 1, it becomes necessary to increase the size of the housing part 131 at least in the height direction so that the inertial sensor 8 does not come into contact with components disposed inside the housing part 131, such as the drive unit 50.

[0080] In contrast, when the inertial sensor 8 is disposed on the lower surface 1311b of the bottom plate 1311 of the housing 131, the housing 131 is prevented from increasing in size in the height direction. This prevents the housing 131 from becoming too large, making it impossible to install the robot 1 on the pedestal 9. Furthermore, it is possible to prevent an increase in the inertia of the second arm 130 from slowing down the operating speed of the second arm 130, thereby reducing the work efficiency of the robot 1, and to prevent an increase in power consumption of the robot 1 from increasing so as not to slow down the operating speed of the second arm 130.

[0081] Furthermore, as Comparative Example 2, consider a case where the inertial sensor 8 is arranged on the underside 1312b of the top plate 1312 of the housing part 131, in other words, a case where the inertial sensor 8 and the motor 51 are arranged on the same top plate 1312. In Comparative Example 2, the distance between the inertial sensor 8 and the motor 51 is small, so the inertial sensor 8 is susceptible to the effects of vibrations caused by driving the motor 51 and electrical noise generated by the motor 51, which may result in a deterioration in detection accuracy.

[0082] In contrast, if the inertial sensor 8 is placed on the underside 1311b of the bottom plate 1311 of the housing part 131, the distance between the inertial sensor 8 and the motor 51 can be increased, thereby reducing the effects of vibrations caused by driving the motor 51 and electrical noise generated by the motor 51, and preventing a decrease in the accuracy of the inertial sensor 8.

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

[0084] In contrast, if the inertial sensor 8 is placed on the underside 1311b of the bottom plate 1311 of the housing part 131, the distance between the inertial sensor 8 and the motor 51 can be increased, thereby reducing the effects of vibrations caused by driving the motor 51 and electrical noise generated by the motor 51, and preventing 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 arranged on the lower surface 1311b of the bottom plate 1311 of the housing part 131 rather than the arrangement examples of the inertial sensor 8 shown in Comparative Example 1, Comparative Example 2, and Comparative Example 3. However, this does not exclude the arrangement examples of the inertial sensor 8 shown in Comparative Example 1, Comparative Example 2, and Comparative Example 3, and the inertial sensor 8 may be arranged as shown in Comparative Example 1, Comparative Example 2, and Comparative Example 3.

[0086] 1.3 Robot System Next, the configuration of the robot system 100 will be described with reference to Figures 1 and 5. Figure 5 is a block diagram of the robot system 100 of Figure 1.

[0087] As described above, the robot system 100 includes the robot 1, the inertial sensor 8 that detects vibrations of the robot 1, and the control device 7 that controls 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 beside the robot 1. The control device 7 may be installed inside the robot 1, for example, built into the base 110, or may be installed in a location away from the robot 1, for example, in a control room provided in a separate building.

[0089] 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 via a bus, for example, so that they can communicate with each other. The control unit 71 is configured with, for example, at least one CPU (Central Processing Unit), and reads and executes various programs, such as operation programs, stored in the storage 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] The control unit 71 also has a position command generation unit, a motor control unit, and multiple motor drivers. The motor control unit performs noise processing, coordinate conversion 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. Then, it generates a feedback value that cancels the vibration component, and controls the motors 21, 31, 511, and 512 of the robot arm 10 using this feedback value.

[0092] Specifically, the position command generation unit calculates a target position of the actuating shaft 41 based on the content of the processing performed by the robot 1, and generates a trajectory for moving the actuating shaft 41 to the calculated target position. The position command generation unit also calculates the rotation angles of the motors 21, 31, 511, and 512 for each predetermined control period so that the actuating shaft 41 moves along the generated trajectory, and outputs the target rotation angles resulting from the calculation to the motor control unit as each position command.

[0093] The motor control unit receives position commands for the motors 21, 31, 511, and 512 and detection signals from the encoders, performs feedback control so that the rotation angles of the motors 21, 31, 511, and 512 coincide with target rotation angles, and outputs control signals to the motor drivers. Furthermore, when driving at least some of the motors, the motor control unit also receives a detection signal from the inertial sensor element 81. The motor control unit, which receives the detection signal from the inertial sensor element 81, calculates a feedback value that cancels vibration components using the detection signal from at least some of the encoders and the detection signal from the inertial sensor element 81, and performs the feedback control described above.

[0094] A motor driver is provided for each of the motors 21, 31, 511, and 512, and operates based on a control signal from the motor control unit. Each motor driver has an inverter circuit including a switching element, converts direct current to alternating current by PWM control, and supplies the alternating current to each of the motors 21, 31, 511, and 512 to drive each of the motors 21, 31, 511, and 512.

[0095] For example, regarding the driving of the motor 31, in addition to the position command for the motor 31, the motor control unit receives detection signals from the encoders of each motor 21, 511, 512 and the inertial sensor 8, and calculates a feedback value using these detection signals.

[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 encoder of the motor 31 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 the motor 31 drives the motor 31 based on the control signal from the motor control unit. By driving the motors 21, 31, 511, and 512 of the robot arm 10 using such feedback values, vibration suppression control can be performed on the first arm 120, the second arm 130, and the working head 40 based on the detection value of the inertial sensor 8.

[0098] Although only one motor control unit is provided in the control unit 71, this is not limiting and multiple motor control units may be provided. When multiple motor control units are provided, there may be a motor control unit corresponding to each of the motors 21, 31, 511, and 512. Furthermore, a configuration may be adopted in which the detection signal from the encoder of the motor 21 is not input to the motor control unit when driving the motor 31. In this case, the motor control unit calculates a feedback value using the detection signals from the encoder of the motor 31 and the inertial sensor 8.

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

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

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

[0102] The control unit 71 may also be configured to perform vibration suppression control only on the working head 40 based on the detection 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 rotating motor 512 of the drive unit 50. When performing vibration suppression control on the working head 40, the feedback value may be used to drive only one of the shaft lifting motor 511 and the shaft rotating motor 512.

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

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

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

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

[0107] The storage unit 72 stores various programs and the like executed by the control unit 71. Examples of the storage unit 72 include a configuration including a volatile memory such as a RAM (Random Access Memory), a non-volatile memory such as a ROM (Read Only Memory), and a removable external storage device.

[0108] The communication unit 73 transmits and receives signals between each part of the robot 1 and the control device 7 using an external interface such as a wired local area network (LAN) or a 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 the robot system 100 of this embodiment have the following advantages. The robot 1 of this embodiment includes a base 110, a first arm 120 having one end in the longitudinal direction overlapping with the base 110 in a plan view, a joint unit 25 serving as a first joint that is provided at one end of the first arm 120 and holds the first arm 120 rotatably about a first axis J1 with respect to the base 110, a second arm 130 having one end in the longitudinal direction overlapping with the other end of the first arm 120 in a plan view, a joint unit 35 serving as a second joint that is provided at one end of the second arm 130 and holds the second arm 130 rotatably about a second axis J2 parallel to the first axis J1 with respect to the first arm 120, and a joint unit 35 serving as a second joint that is provided at one end of the second arm 130 and holds the second arm 130 rotatably about a second axis J2 parallel to the first axis J1 with respect to the second arm 130. The second arm 130 has a housing part 131 having a bottom plate 1311 as a first plate part, a motor 51 arranged on the top surface 1311a side as a first surface of the bottom plate 1311 between the operating shaft 41 and the second axis J2, and configured to rotate the operating shaft 41 around a third axis J3 parallel to the second axis J2 or move the operating shaft 41 along the third axis J3, and an inertial sensor 8 arranged on the bottom surface 1311b side as a second surface opposite the top surface 1311a of the bottom plate 1311 in a position overlapping with the motor 51 in a plan view, and configured to detect at least one of angular velocity and acceleration.

[0110] As described above, in the robot 1 of this embodiment, the inertial sensor 8 is disposed on the lower surface 1311b, opposite the upper surface 1311a of the bottom plate 1311. Therefore, in the robot 1 of this embodiment, an increase in the arm length of the second arm 130 can be prevented, and an increase in the inertia of the second arm 130 rotating about the second axis J2 can be prevented. Furthermore, because an increase in the size of the housing unit 131 in the height direction is prevented, it is possible to prevent the robot 1 from becoming unable to be installed on the pedestal 9 and an increase in the inertia of the second arm 130.

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

[0112] In this way, by arranging the shaft lifting motor 511 and the shaft rotating motor 512 next to each other along the longitudinal direction of the second arm 130, the arm length of the second arm 130 becomes longer, but the robot 1 of this embodiment can prevent the arm length of the second arm 130 from becoming longer than necessary.

[0113] In the robot 1 of this embodiment, the housing part 131 has a bottom plate 1311 as a first plate part and a top plate 1312 as a second plate part that overlaps with the bottom plate 1311, 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 driving 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 as the second plate portion has a lower surface 1312b as the third surface facing the upper surface 1311a as the first surface of the bottom plate 1311 as the first plate portion, and an upper surface 1312a as the fourth surface opposite the lower surface 1312b, the motor 51 is fixed to the upper surface 1312a, and the inertial sensor 8 is positioned so as to overlap the motor 51 in a planar view.

[0116] In this way, the motor 51 is fixed to the upper surface 1312a of the top plate 1312, and the inertial sensor 8 is disposed at a position overlapping the motor 51 in a plan view. Therefore, the arm length of the second arm 130 can be prevented from increasing, and therefore, the inertia of the second arm 130 rotating around the second axis J2 can be prevented from increasing.

[0117] The robot system 100 of this embodiment includes the above-described robot 1 and a control device 7 as a controller that controls the robot 1. Therefore, it is possible to realize a robot system 100 that has high work accuracy and is highly useful in industry.

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

[0119] The second embodiment shows another example of the arrangement of the inertial sensor 8 shown in the first embodiment. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and redundant description will be omitted.

[0120] 6A to 6C , the inertial sensor 8 is provided at a position overlapping the motor 51 in a plan view. In the robot 1 of the second embodiment, the shaft lifting motor 511 and the shaft rotating motor 512 serving as the motor 51 are provided adjacent to each other along the short side direction of the second arm 130.

[0121] In the second embodiment, the shaft lifting motor 511 and the shaft rotating motor 512 are provided adjacent to each other along the short side of the second arm 130, so the arm length of the second arm 130 can be made shorter than in the first embodiment. Therefore, the inertia of the second arm 130 rotating around the second axis J2 can be made smaller than in the first embodiment. Note that the motor 51 overlapping the inertial sensor 8 in a plan view may be both the shaft lifting motor 511 and the shaft rotating motor 512, or either one of them.

[0122] The inertial sensor 8 is disposed on the second arm 130 between the actuation shaft 41 and the second axis J2, but is disposed at a position overlapping with the motor 51 in a plan view, which makes it possible to prevent the arm length of the second arm 130 from becoming long. Furthermore, compared to when the inertial sensor 8 is disposed between the motor 51 and the actuation shaft 41, the length of the second arm 130 in the short direction, i.e., the arm length, can be made shorter.

[0123] In this way, in this embodiment, even if the inertial sensor 8 is provided on the second arm 130, it is possible to prevent the arm length of the second arm 130 from becoming longer or to shorten the arm length of the second arm 130.

[0124] In the second embodiment, it is possible to prevent the arm length of the second arm 130 from increasing, and therefore it is possible to prevent an increase in the inertia of the second arm 130 rotating around the second axis J. Therefore, such an arrangement of the inertia sensor 8 makes it possible to avoid a decrease in the operating speed of the second arm 130, which would result in a decrease in work efficiency, or an increase in power consumption due to an increase in power to prevent a decrease in the operating speed of the second arm 130.

[0125] Furthermore, in the second embodiment, the arm length of the second arm 130 can be shortened, thereby reducing the inertia of the second arm 130 that rotates around the second axis J2. Therefore, such an arrangement of the inertia sensor 8 can increase the operating speed of the second arm 130, thereby improving work efficiency, and can reduce the size of the motor 31, thereby reducing power consumption.

[0126] 6A to 6C, the inertial sensor 8 of the second embodiment is disposed on the lower surface 1311b opposite to the upper surface 1311a of the bottom plate 1311 of the housing 131, as in the first embodiment. This arrangement provides excellent effects, as in the first embodiment.

[0127] Furthermore, in the second embodiment, similar to the first embodiment, the motor 51 is provided adjacent to the working head 40. Therefore, the inertial sensor 8, which is provided at a position overlapping the motor 51 in a plan view, can accurately detect vibrations caused by driving the working head 40. Therefore, the detection signal of such an inertial sensor 8 can be used to perform vibration suppression control, thereby improving the working accuracy of the robot 1.

[0128] 6C , a connector group 6 is provided on the lower surface 1311b of the second arm 130 at a position overlapping with the cylindrical portion 132. The connector group 6 includes, 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 has the following advantages in addition to the advantages of embodiment 1. In the robot 1 of this embodiment, the motor 51 includes a shaft lifting motor 511 as a first motor and a shaft rotating motor 512 as a second motor, and the shaft lifting motor 511 and the shaft rotating motor 512 are provided adjacent to each other along the short side direction of the second arm 130.

[0130] In this way, by arranging the shaft lifting motor 511 and the shaft rotating motor 512 next to each other along the short side of the second arm 130, the arm length of the second arm 130 can be shortened, but even if an inertial sensor 8 is provided on the second arm 130, the arm length of the second arm 130 can be prevented from becoming longer.

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

[0132] Embodiment 3 shows yet another example of the arrangement of the inertial sensor 8 shown in Embodiments 1 and 2. In the following description, the same reference numerals are used for the same components as those in Embodiments 1 and 2, and duplicated descriptions will be omitted.

[0133] 7A and 7B , in the third embodiment, the inertial sensor 8 is provided on the lower surface 1311b of the housing 131 at a position overlapping the cylindrical portion 132 in a plan view. In other words, the inertial sensor 8 is disposed at a position closer to the second axis J2 than the motor 51 in a plan view.

[0134] In this way, the inertial sensor 8 of the third embodiment is provided at a position closer to the second axis J2 than the motor 51 in a plan view and at a position overlapping with the cylindrical portion 132, and is therefore able to accurately detect vibrations, particularly torsional vibrations, of the cylindrical portion 132. Furthermore, the distance between the inertial sensor 8 and the motor 51 can be increased, which reduces the effects of vibrations caused by driving the motor 51 and electrical noise generated by the motor 51, and thus prevents the accuracy of the inertial sensor 8 from decreasing.

[0135] As described above, the robot 1 of the third embodiment has the following advantages in addition to the advantages of the first and / or second embodiment. The robot 1 of the present embodiment includes a base 110, a first arm 120 having one end in the longitudinal direction overlapping with the base 110 in a plan view, a joint unit 25 serving as a first joint that is provided at one end of the first arm 120 and holds the first arm 120 rotatably about a first axis J1 relative to the base 110, a second arm 130 having one end in the longitudinal direction overlapping with the other end of the first arm 120 in a plan view, a joint unit 35 serving as a second joint that is provided at one end of the second arm 130 and holds the second arm 130 rotatably about a second axis J2 parallel to the first axis J1 relative to the first arm 120, and a joint unit 35 serving as a second joint that is provided at the other end of the second arm 130 in the longitudinal direction. The second arm 130 has a housing part 131 having a bottom plate 1311 as a first plate part, a motor 51 arranged on the top surface 1311a side as a first surface of the bottom plate 1311 between the operating shaft 41 and the second axis J2, and configured to rotate the operating shaft 41 around a third axis J3 parallel to the second axis J2 or move the operating shaft 41 along the third axis J3, and an inertial sensor 8 arranged on the bottom surface 1311b side as a second surface opposite the top surface 1311a of the bottom plate 1311, at a position closer to the second axis J2 than the motor 51 in a planar view, and configured to detect at least one of angular velocity and acceleration.

[0136] As described above, in the robot 1 of this embodiment, the inertial sensor 8 is disposed at a position closer to the second axis J2 than the motor 51 in a plan view. Therefore, the inertial sensor 8 can accurately detect vibrations of the tubular portion 132, in particular torsional vibrations.

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

[0138] Although the embodiments of the robot 1 and the robot system 100 have been described above, the present invention is not limited to these. Furthermore, each part of the robot system 100 can be replaced with any structure that can perform a similar function. Furthermore, any structure may be added to the robot system 100. Furthermore, the present invention may also be a combination of some of the features of each embodiment.

[0139] 1...robot, 6...connector group, 61, 62, 63, 64, 65...connectors, 7...control device, 8...inertial sensor, 81...inertial sensor element, 82...substrate, 9...frame, 91...top plate, 911...upper surface, 912...lower surface, 913, 914...through holes, 92...workbench, 93...legs, 95...work, 10...robot arm, 11...main body, 12...metal fittings, 13...base plate, 20...drive unit , 21...motor, 22...belt, 23...pulley, 25...joint portion, 26...reduction gear, 261...wave generator, 262...flexspline, 263...circular spline, 27...flange, 28...hollow tube, 30...drive portion, 31...motor, 32...belt, 33...pulley, 35...joint portion, 36...reduction gear, 361...wave generator, 362...flexspline, 363...circular spline, 37...flange, 38...hollow tube, 40...work head, 41...operating shaft, 42...hand, 43...cover member, 50...drive portion, 51...motor, 511...shaft lifting motor, 512...shaft rotating motor, 52...belt, 53...pulley, 54...lead screw mechanism, 541...female thread 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...upper surface, 1311b...lower surface, 1312...top plate, 1312a...upper surface, 1312b...lower surface, 132...tubular unit, J1...first axis, J2...second axis, J3...third axis.

Claims

1. A device comprising: a base; a first arm having one end in a longitudinal direction overlapping the base in a plan view; a first joint provided at the one end of the first arm and holding the first arm rotatably about a first axis relative to the base; a second arm having one end in a longitudinal direction overlapping the other end of the first arm in a plan view; a second joint provided at the one end of the second arm and holding the second arm rotatably about a second axis parallel to the first axis relative to the first arm; and a shaft provided at the other end of the second arm in the longitudinal direction, wherein the second arm comprises: a housing having a first plate; and a motor disposed between the shaft and the second axis on a first surface side of the first plate, and configured to rotate the shaft about a third axis parallel to the second axis or move the shaft along the third axis. an inertial sensor that is arranged on a second surface side of the first plate portion opposite the first surface at a position that overlaps with the motor or is closer to the second axis than the motor in a plan view, and that detects at least one of angular velocity and acceleration.

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

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

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

5. The robot described in claim 4, wherein the second plate portion has a third surface facing the first surface of the first plate portion and a fourth surface opposite the third surface, the motor is fixed to the fourth surface, and the inertial sensor is positioned so as to overlap the motor in a planar view.

6. The robot according to claim 1, wherein the housing has a cylindrical portion surrounding the second axis, and the inertial sensor is provided at a position overlapping the cylindrical portion in a plan view.

7. A robot system comprising: a robot according to any one of claims 1 to 6; and a controller that controls the robot.

Images