JP2020001125A - Scalar robot - Google Patents

Abstract

To provide a scalar robot that can more safely perform work together with a person.SOLUTION: The scalar robot comprises: a base; a first arm which is provided in the base, and turns around a first shaft; a second arm which is provided in the first arm, and turns around a second shaft parallel to the first shaft; a shaft which penetrates through the second arm and moves in an axial direction of a third shaft parallel to the second shaft with respect to the second arm; movable part which comprises a cover which is provided in the second arm and covers a site protruding toward the opposite side to a placement surface having the base placed thereon, from the second arm of site that the shaft has, and a protective member which covers a part of a site protruding from the second arm toward the placement surface of the site that the shaft has; a contact detecting part that detects contact of the protective member with one or both of a person and an object; and a first processor that stops motion of the movable part on the basis of output of the contact detecting part.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a SCARA robot.

  Research and development of industrial robots are being conducted.

  As an industrial robot, for example, a scalar robot (horizontal articulated robot) having two arms and moving these two arms along a horizontal direction is known (see Patent Literature 1). In such a SCARA robot, at least a part of an arm of the SCARA robot is rotatable around an axis orthogonal to a horizontal direction, has a shaft translatable along the axis, and has an end attached to the shaft. The effector performs a predetermined operation on the object.

JP 2011-101907 A

  The SCARA robot may be used as a human collaboration robot that works with a human. However, when attempting to use a conventional SCARA robot as described in Patent Literature 1 as a human collaboration robot, the shaft of the SCARA robot may come into contact with a person or an object other than a person. For this reason, it is necessary for the SCARA robot to take measures to suppress contact with a person or an object other than a person. Here, the object other than the person includes an object that does not actively move from the arranged position, an object that passively moves according to the movement of the person, and the like. The object that passively moves according to the movement of the person is, for example, an object on which the person works, an object held by the person, and the like.

  According to one embodiment of the present invention, there is provided a base, a first arm provided on the base, and rotated around a first axis, and a first arm provided on the first arm. A second arm that rotates about a second axis parallel to the second arm, a shaft that penetrates the second arm, and moves in an axial direction of a third axis that is parallel to the second axis with respect to the second arm; A cover provided on the second arm and covering a portion of the shaft that protrudes from the second arm toward a side opposite to an installation surface on which the base is installed; A movable member including a protection member that covers a part of the portion protruding from the second arm toward the installation surface; and one or both of a person and an object, and contacting the protection member. A contact detection unit to be detected, based on an output of the contact detection unit; A first processor for stopping the operation of the movable part, a scalar robot comprising a.

FIG. 1 is a diagram illustrating an example of a configuration of a robot system 1 according to an embodiment. FIG. 2 is a diagram illustrating an example of a hardware configuration of a robot control device 30. It is a figure showing an example of composition of protection member DM. It is a figure showing other examples of composition of protection member DM.

<Embodiment>
Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<Robot system configuration>
First, the configuration of the robot system 1 will be described.
FIG. 1 is a diagram illustrating an example of a configuration of a robot system 1 according to the embodiment. The robot system 1 includes a robot 20 and a robot control device 30.

  The robot 20 is a SCARA robot. Further, the robot 20 is a human collaboration robot. A human collaboration robot is a robot that can work with a human. Hereinafter, for convenience of explanation, a person who works with the robot 20 will be simply referred to as a worker. A worker is an example of a person.

  The robot 20 includes a base B, a movable unit A, and a contact detection unit TS.

  The base B supports the movable part A. In the example shown in FIG. 1, the base B is installed on a predetermined installation surface. The installation surface is, for example, a floor surface of a room where the robot 20 performs work. The installation surface may be another surface such as a wall surface of the room, a ceiling surface of the room, an upper surface of a table, a surface of a jig, and a surface of a table, instead of the floor surface.

  Here, for convenience of description, a direction from the base B to the installation surface among directions orthogonal to the installation surface will be referred to as a downward direction or a downward direction. In the following, for convenience of explanation, a direction opposite to the downward direction will be referred to as an upward direction or an upward direction. In the following, a case where the downward direction coincides with the direction of gravity will be described as an example. In addition, hereinafter, as an example, a case where the downward direction coincides with the negative direction of the Z axis in the robot coordinate system RC will be described. The robot coordinate system RC is a robot coordinate system of the robot 20.

  The contact detection unit TS detects that one or both of an operator not shown in FIG. 1 and an object X not shown in FIG.

  Here, the object X includes, for example, an object that does not actively move from the arranged position, an object that passively moves according to the movement of the worker, and the like. The objects that do not move from the arranged position are, for example, a jig after being arranged, a work after being supplied, a tool after being arranged, a safety fence after being arranged, another robot, and the like. . The jig is a jig used by the robot 20 during work. The work is an object on which the robot 20 works. The tool is a tool used by the robot 20 during work. The safety fence is a fence installed around the robot 20 so that a person other than the worker does not approach the robot 20. An object that passively moves in response to the movement of the worker is, for example, an object that the worker performs work, such as a work before being supplied by the worker, or an object that the worker has, such as a teaching pendant. is there. Instead of these, the object X may include any other object different from the worker and the robot 20.

  Hereinafter, as an example, a case will be described in which an operator may contact the robot 20 and there is no possibility that the object X will contact the robot 20. In this case, the contact detection unit TS detects that the worker has contacted the robot 20.

  The contact detection unit TS is, for example, a force sensor (force sensor). In this case, the contact detection unit TS detects the external force acting on the robot 20 as contact information indicating whether or not an operator has contacted the robot 20. This is because when an operator comes into contact with the robot 20, an external force is applied to the robot 20 from the operator. The external force acting on the robot 20 includes one or both of a translational force and a rotational moment. The translation force is a force that attempts to translate the robot 20. The rotation moment is a moment for rotating the robot 20. The contact detection unit TS outputs the detected contact information to the robot control device 30.

  In the example shown in FIG. 1, the contact detection unit TS is provided between the base B and the installation surface. That is, in this example, the base B is installed on the installation surface via the contact detection unit TS.

  As in this example, when the contact detection unit TS is a force sensor, the robot control device 30 determines that the external force acting on the robot 20 is equal to or greater than a predetermined threshold based on, for example, the acquired contact information. In this case, it is determined that the worker has contacted the robot 20. By adjusting the threshold value, the robot control device 30 can distinguish between the contact between the robot 20 and the object to be grasped by the robot 20 and the contact between the worker and the robot 20. .

  Here, the contact between the worker and the robot 20 detected by the contact detection unit TS means a part or all of the contact between the worker and the robot 20. That is, for example, when the worker contacts a protection member DM described later, the contact detection unit TS detects the contact between the protection member DM and the worker. As a result, the contact detection unit TS detects that the worker has contacted the robot 20.

  Note that the robot system 1 distinguishes between the worker's contact with the robot 20 and the object X's contact with the robot 20 when both the worker and the object X may contact the robot 20. If it is desired to do so, a configuration may be adopted in which a sensor capable of distinguishing and detecting a contact of an operator X with the robot 20 and a contact of the object X with the robot 20 is provided as a contact detection unit TS together with a force sensor. The sensor is, for example, a temperature sensor, an infrared sensor, a camera connected to an image processing device, or the like. Thereby, in the robot system 1, the contact detection unit TS can separately detect that the worker has contacted the robot 20 and that the object X has contacted the robot 20. In addition, when there is a possibility that both the worker and the object X may contact the robot 20, the robot system 1 distinguishes that the worker has contacted the robot 20 and that the object X has contacted the robot 20. If desired, a configuration may be adopted in which a sensor capable of distinguishing and detecting the contact of the worker X with the robot 20 and the contact of the object X with the robot 20 is provided as the contact detection unit TS instead of the force sensor. Thereby, in the robot system 1, the contact detection unit TS can separately detect that the worker has contacted the robot 20 and that the object X has contacted the robot 20.

  The movable part A is supported by a base B so as to be rotatable around a first rotation axis AX1 and by the first arm A1 so as to be rotatable about a second rotation axis AX2. A second arm A2 and a shaft S supported by the second arm A2 so as to be rotatable around the third rotation axis AX3 and to be able to translate in the axial direction of the third rotation axis AX3 are provided.

  The shaft S is a cylindrical shaft. On the peripheral surface of the shaft S, a ball screw groove and a spline groove (not shown) are respectively formed. In this example, the shaft S is provided by vertically penetrating an end of the second arm A2 opposite to the first arm A1. Here, a cover CV described later, which is separate from the second arm A2, is attached to the second arm A2 shown in FIG. Therefore, from the outside of the cover CV, it cannot be seen that the shaft S vertically passes through the end of the second arm A2 opposite to the first arm A1. In FIG. 1, the manner in which the shaft S penetrates the end in the up-down direction is indicated by a dotted line.

  An external device such as an end effector can be attached to the tip of the shaft S. The tip of the shaft S is the lower end of the two ends of the shaft S. Nothing is attached to the tip of the shaft S shown in FIG. The end effector attached to the tip of the shaft S is, for example, an end effector that can hold an object by a finger portion, or an end effector that can hold an object by air, magnetism, or the like. Note that the end effector attached to the tip of the shaft S may be an end effector that cannot hold an object, instead. In the present embodiment, to hold the object means to make the object liftable.

  In this example, the first arm A1 rotates around the first rotation axis AX1 and moves in the horizontal direction. The horizontal direction is a direction orthogonal to the vertical direction. That is, in this example, the horizontal direction is a direction along an XY plane which is a plane extended by the X axis and the Y axis in the robot coordinate system RC. Note that the horizontal direction may be a direction that is not orthogonal to the vertical direction, instead of the direction orthogonal to the vertical direction. Further, the horizontal direction may be a direction not along the XY plane, instead of the direction along the XY plane.

  Further, the first arm A1 is rotated (driven) around the first rotation axis AX1 by a first motor (not shown) of the base B. The first motor rotates the first arm A1 around the first rotation axis AX1. That is, in this example, the first rotation axis AX1 is a virtual axis coinciding with the rotation axis of the first motor. Note that the first rotation axis AX1 may be a virtual axis that does not coincide with the rotation axis of the first motor.

  In this example, the second arm A2 rotates around the second rotation axis AX2 and moves in the horizontal direction. The second arm A2 is rotated around the second rotation axis AX2 by a second motor (not shown) of the second arm A2. The second motor rotates the second arm A2 around the second rotation axis AX2. That is, in this example, the second rotation axis AX2 is a virtual axis coinciding with the rotation axis of the second motor. The second rotation axis AX2 may be a virtual axis that does not coincide with the rotation axis of the second motor.

  The second arm A2 includes a third motor (not shown) and a fourth motor (not shown), and supports the shaft S. The third motor rotates a ball screw nut provided on an outer peripheral portion of the ball screw groove of the shaft S with a timing belt or the like. Thus, the third motor moves (elevates) the shaft S in the vertical direction. The fourth motor rotates a ball spline nut provided on an outer peripheral portion of the spline groove of the shaft S with a timing belt or the like. Thus, the fourth motor rotates the shaft S around the third rotation axis AX3. That is, the third rotation axis AX3 is a virtual axis coinciding with the central axis of the shaft S. Note that the third rotation axis AX3 may be a virtual axis that does not coincide with the central axis of the shaft S.

  As described above, the cover CV that is separate from the second arm A2 is attached to the second arm A2. The cover CV covers an upper projecting portion of the shaft S. The upper projecting portion of the shaft S is a portion of the shaft S that projects upward from the second arm A2. The length of the upper protruding portion of the shaft S in the direction along the third rotation axis AX3 changes due to the vertical movement of the shaft S. For this reason, the cover CV is a cover large enough to cover the entire upper protruding portion of the shaft S even when the shaft S moves upward to the limit position where the shaft S can move upward.

  Further, in the example shown in FIG. 1, the cover CV covers other members provided on the second arm A2 together with the upper projecting portion of the shaft S. That is, in this example, each of the above-described second motor, third motor, and fourth motor is provided in a space surrounded by the second arm A2 and the cover CV. Note that the cover CV may be separate from the cover that covers the other member. In this case, the robot 20 may not have a cover that covers the other member.

  Since the cover CV is attached to the second arm A2, it is difficult for the worker and the object X to come into contact with the upper projecting portion of the shaft S from outside the cover CV. As a result, the robot 20 determines that the worker comes into contact with the upper protruding portion of the shaft S (for example, that the worker comes into contact with the upper protruding portion of the shaft S, and the like). (For example, a teaching pendant carried by an operator comes into contact with the upper protruding portion of the shaft S, or the like), or Both can be suppressed. In addition, since the cover CV is attached to the second arm A2, the robot 20 has the operator's finger, the clothes worn by the operator, and the worker between the upper projecting portion of the shaft S and the second arm. Can be prevented from being pinched by the object X or the like held by the user. That is, the provision of the cover CV allows the robot 20 to prevent the worker from contacting a part of the shaft S and to prevent the object X from contacting a part of the shaft S. Either or both can be suppressed. The clothes worn by the worker may be included in the configuration of the worker or may be included in the object X held by the worker.

  Further, the second arm A2 is provided with a protection member DM that covers a part of the lower projecting portion of the shaft S. The lower protruding portion of the shaft S is a portion of the shaft S that protrudes downward from the second arm A2.

  Hereinafter, as an example, a case will be described in which the protection member DM is a cylindrical member that covers a part of the side surface of the lower protruding portion of the shaft S. The side surface of the lower protruding portion of the shaft S is a surface of the lower protruding portion of the shaft S that is located in a direction orthogonal to the axial direction of the shaft S. That is, in this example, the lower projecting portion of the shaft S is inserted inside the protection member DM. In this case, the inner diameter of the protection member DM may be slightly larger than the outer diameter of the shaft S, or may be sufficiently larger than the outer diameter of the shaft S. When the inner diameter of the protection member DM is slightly larger than the outer diameter of the shaft S, the inner diameter of the protection member DM is, for example, about 0.1 to 1 mm larger than the outer diameter of the shaft S. That is, in this case, there is almost no gap between the protection member DM and the shaft S. If there is no gap between the protection member DM and the shaft S, some measures to reduce the friction coefficient such as application of lubricating oil such as grease for reducing the friction coefficient are taken inside the protection member DM. Is desirable. Another example of such a measure is to use a material having a low friction coefficient for the material of the protection member DM. On the other hand, when the inner diameter of the protection member DM is sufficiently larger than the outer diameter of the shaft S, the inner diameter of the protection member DM is, for example, 1 mm or more larger than the outer diameter of the shaft S. That is, in this case, a gap exists between the protection member DM and the shaft S. Hereinafter, a case where the inner diameter of the protection member DM is sufficiently larger than the outer diameter of the shaft S will be described as an example.

  Further, the protection member DM has a first portion EG1 and a second portion EG2.

  The first portion EG1 is a portion attached to a predetermined portion of the second arm A2 among the portions of the protection member DM. In this example, the protection member DM is a cylindrical member. In this case, the first portion EG1 of the protection member DM is, for example, an upper end of two ends of the protection member DM. In this case, the predetermined part of the second arm A2 is, for example, a part of the lower surface of the second arm A2 that surrounds the opening through which the shaft S passes. The predetermined part of the second arm A2 may be another part of the second arm A2 instead. In addition, the first portion EG1 is not the upper end of the two ends of the protection member DM but is another portion of the portion of the protection member DM that is different from the second portion EG2. There may be. In this case, the first portion EG1 is attached to the second arm A2 by a member that supports the first portion EG1. Further, a configuration may be employed in which a bearing is provided between the first portion EG1 and the shaft S.

  The second part EG2 is a part that is attached to a predetermined part of the shaft S among the parts of the protection member DM. In this example, the protection member DM is a cylindrical member. In this case, the second portion EG2 is a lower end of the two ends of the protection member DM. In this case, the predetermined portion of the shaft S is the tip of the shaft S. However, it is desirable that the second portion EG2 be mounted at a position on the tip of the shaft S that does not hinder the mounting of the end effector. The predetermined part of the shaft S may be another part of the shaft S instead. In addition, the second portion EG2 is replaced with another lower portion of the two ends of the protection member DM as long as the portion is different from the first portion EG1 of the portions of the protection member DM. It may be.

  Here, in this example, as described above, the first portion EG1 is attached to the second arm A2. In this case, the second portion EG2 needs to be attached to the shaft S so as not to rotate with the shaft S. This is to prevent the protection member DM from being twisted by the rotation of the shaft S. For example, the second portion EG2 may have a configuration in which a convex portion that fits into a groove formed along the upper circumference by a predetermined length from the tip of the shaft S is formed on the inner surface. . In this case, the second portion EG2 is attached to the shaft S by hooking the projection on the groove. When the second part EG2 is attached to the shaft S in this manner, the second part EG2 does not rotate with the shaft S because the groove is formed along the circumference. Further, the second portion EG2 may be configured to be attached to the tip of the shaft S via a bearing. In this case, the second portion EG2 is fixed to the outer periphery of the bearing. Then, the bearing is fitted into the groove. Thereby, the robot 20 can suppress the shaft S from being worn due to the contact between the second portion EG2 and the shaft S. Further, the robot 20 can suppress an increase in energy required for driving the shaft S due to such wear. Further, the second portion EG2 may not be attached to the shaft S.

  Note that the first portion EG1 may not be attached to the second arm A2, but may be configured to be pressed against the lower surface of the second arm A2 by the elasticity of the protection member DM. In this case, since the first portion EG1 is not fixed to the second arm A2, the second portion EG2 may be configured to be attached to the tip of the shaft S so as to rotate with the shaft S. However, when the first portion EG1 is pressed against the lower surface of the second arm A2 by the elasticity of the protection member DM, grease or the like that reduces the friction coefficient between the protection member DM and the lower surface of the second arm A2. It is desirable to take some measures to lower the coefficient of friction, such as applying a lubricating oil. Another example of such a measure is to use a material having a low friction coefficient for the material of the protection member DM. In this case, a bearing is desirably provided between the first portion EG1 and the shaft S. Thereby, the robot 20 can suppress the shaft S from being worn due to the contact between the first portion EG1 and the shaft S. Further, the robot 20 can suppress an increase in energy required for driving the shaft S due to such wear. Further, the first portion EG1 may not be attached to the second arm A2 and may not be pressed against the lower surface of the second arm A2 by the elasticity of the protection member DM. In this case, it is desirable that a bearing be provided between the first portion EG1 and the shaft S.

  Here, the length of the lower protruding portion of the shaft S in the direction along the third rotation axis AX3 is the same as the length of the upper protruding portion of the shaft S in the direction along the third rotation axis AX3. It changes with the vertical movement of S. For this reason, the protection member DM in this example is a cylindrical member that expands and contracts in the axial direction of the shaft S. That is, the length of the protection member DM in the direction along the third rotation axis AX3 changes as the shaft S moves up and down.

  Since the protection member DM expands and contracts in the axial direction of the shaft S as the shaft S moves up and down, the robot 20 can move the shaft S up and down without breaking the protection member DM. A specific example of the configuration of such a protection member DM will be described later.

  Since the robot 20 is provided with the protection member DM, it is difficult for the worker and the object X to come into contact with a portion of the lower projecting portion of the shaft S that is covered by the protection member DM from outside the protection member DM. Accordingly, the robot 20 may cause the worker to come into contact with a part of the lower projecting part of the shaft S that is covered by the protection member DM (for example, the worker may And that the object X comes into contact with a portion of the lower projecting portion of the shaft S which is covered by the protection member DM (for example, a teaching pendant carried by an operator). May contact the upper projecting portion of the shaft S, etc.). Further, since the robot 20 is provided with the protection member DM, the robot 20 is provided between the second arm A2 and the portion of the lower projecting portion of the shaft S which is covered by the protection member DM, and the Can be prevented from being pinched by clothes worn by the user, an object X held by the worker, and the like.

  Note that the protection member DM may be another member that covers a part of the lower projecting portion of the shaft S, instead of the cylindrical member described above.

  The robot control device 30 causes the robot 20 to perform a predetermined operation under control based on an operation program stored in advance.

  Here, the robot control device 30 is communicably connected to the robot 20 by wire or wirelessly.

  In addition, the robot control device 30 has various functions necessary for operating the robot 20 as a human cooperative robot. The various functions include a task of working with the robot 20 around the robot 20, such as a function of preventing the robot 20 from contacting a worker working with the robot 20 around the robot 20. Includes features that enhance the safety of the aged. The robot control device 30 has, for example, a function of suppressing an unintended operation performed by the robot 20 when an error occurs in a processor included in the robot control device 30 as one of such functions. . In order to realize this function, the robot control device 30 includes two processors as shown in FIG.

  FIG. 2 is a diagram illustrating an example of a hardware configuration of the robot control device 30. The robot control device 30 includes, for example, a first processor 31, a second processor 32, a memory 33, and a communication unit 34. These components are communicably connected to each other via a bus. The robot control device 30 communicates with the robot 20 via the communication unit 34.

  The first processor 31 is, for example, a CPU (Central Processing Unit). Note that the first processor 31 may be another processor such as an FPGA (Field Programmable Gate Array). The first processor 31 executes various programs stored in the memory 33. As a result, the first processor 31 operates the movable part A of the robot 20 to cause the robot 20 to perform a predetermined operation. In addition, when an abnormality occurs in the second processor 32, the first processor stops the operation of the movable unit A. Accordingly, even when an abnormality occurs in the second processor 32, the robot control device 30 causes the robot 20 to contact a worker who is working with the robot 20 by an unintended operation of the robot 20. Can be suppressed. As a result, the robot control device 30 can improve the safety of the robot 20, and can operate the robot 20 as a human cooperative robot. Here, the abnormality that occurs in the second processor 32 is, for example, a failure of part or all of the second processor 32 due to heat generation, electric leakage, or the like, or a stop of power supply to the second processor 32 due to disconnection or the like.

  The second processor 32 is, for example, a CPU. Note that the second processor 32 may be another processor such as an FPGA. The second processor 32 executes various programs stored in the memory 33. As a result, the second processor 32 operates the movable part A included in the robot 20, and causes the robot 20 to perform a predetermined operation. Further, the second processor 32 stops the operation of the movable unit A when an abnormality occurs in the first processor 31. Thus, even when an abnormality occurs in the first processor 31, the robot control device 30 makes the robot 20 come into contact with a worker working with the robot 20 by an unintended operation of the robot 20. Can be suppressed. As a result, the robot control device 30 can improve the safety of the robot 20, and can operate the robot 20 as a human cooperative robot. Here, the abnormality that occurs in the first processor 31 is, for example, a failure of part or all of the first processor 31 due to heat generation, electric leakage, or the like, or a stop of power supply to the first processor 31 due to disconnection or the like.

  The memory 33 includes, for example, a hard disk drive (HDD), a solid state drive (SSD), an electrically erasable programmable read-only memory (EEPROM), a read-only memory (ROM), and a random access memory (RAM). Note that the memory 33 may be an external storage device connected by a digital input / output port such as a USB (Universal Serial Bus) instead of the one built in the robot control device 30. The memory 33 stores various information processed by the robot control device 30, various images, operation programs, and the like.

  The communication unit 34 includes, for example, a digital input / output port such as a USB, an Ethernet (registered trademark) port, and the like.

  Note that the robot control device 30 may be configured to include an input device such as a keyboard, a mouse, and a touchpad. Further, the robot control device 30 may be configured to include a display device including a liquid crystal display panel, an organic EL (ElectroLuminescence) display panel, and the like.

  As described in FIG. 2, the robot control device 30 includes two processors, the first processor 31 and the second processor 32. Then, in the robot control device 30, these two processors monitor whether or not an abnormality has occurred with each other, and when one of the processors has an abnormality, the operation of the robot 20 is stopped. Accordingly, the robot control device 30 can prevent the robot 20 from performing an unintended operation. As a result, the robot control device 30 can operate the robot 20 more safely as a human cooperative robot.

  In the example illustrated in FIG. 1, the robot control device 30 is installed outside the robot 20, but may be configured to be built in the robot 20 instead.

<Specific example of configuration of protective member>
Hereinafter, a specific example of the configuration of the protection member DM will be described. The specific example of the configuration of the protection member DM described below is merely an example. For this reason, the protection member DM may have another configuration instead of the configuration described below.

  First, the configuration of the protection member DM relating to the elasticity of the protection member DM along the central axis of the protection member DM will be described. As described above, the protection member DM expands and contracts in the axial direction of the shaft S as the shaft S moves up and down. For this reason, the protection member DM may be configured to be made of one or both of a material and a structure having elasticity in a direction along the central axis of the protection member DM. In this case, for example, as shown in FIG. 3, the protection member DM is a tubular member and has a mesh-like structure. FIG. 3 is a diagram illustrating an example of the configuration of the protection member DM. As shown in FIG. 3, when the protective member DM has a mesh-like structure, the material of the protective member DM may be a material that does not expand or contract or almost does not expand and contract. For this reason, in the example shown in FIG. 3, the material of the protection member DM is carbon. The mesh structure shown in FIG. 3 is a structure in which the mesh is hexagonal (that is, a honeycomb structure). The mesh size of the protection member DM shown in FIG. 3 is desirably a size that does not allow a worker's finger to enter, but may be a size that allows a worker's finger to enter. The material of the protection member DM may be an elastic material such as nylon, as in the example shown in FIG. FIG. 4 is a diagram illustrating another example of the configuration of the protection member DM. Also in the example shown in FIG. 4, the protection member DM is a cylindrical member and has a mesh-like structure. The mesh structure shown in FIG. 4 is a structure in which the mesh is a square (rectangle). The size of the mesh of the protection member DM shown in FIG. 4 is desirably a size that does not allow the operator's finger to enter, but may be a size that allows the operator's finger to enter.

  Further, the protection member DM may be configured to have another structure having elasticity in a direction along the central axis of the protection member DM, instead of the configuration having the mesh structure. For example, the protection member DM may be configured to have a structure that expands and contracts in a direction along the central axis of the protection member DM by a telescopic mechanism. In this case, the material of the protection member DM is plastic, acrylic, metal, carbon, or the like, but is not limited thereto. Further, for example, the protection member DM may have a structure having a structure that expands and contracts in a direction along the central axis of the protection member DM by a winding mechanism of a roll curtain or the like. In this case, the material of the protection member DM is resin, paper, cloth, or the like, but is not limited thereto. Further, for example, the protection member DM may have a configuration in which the protection member DM has elasticity along the central axis of the protection member DM and is a tubular rubber or the like having no mesh.

  Further, for example, the protection member DM may be a bellows-type tube. Further, for example, the protection member DM includes a plurality of rings arranged along the virtual axis so that a certain virtual axis coincides with each central axis, and the plurality of arranged In the above-mentioned ring, adjacent rings may be members connected by an elastic material such as rubber. In this case, in the protection member DM, the distance between adjacent rings changes due to the elasticity of the material. Thereby, the protection member DM expands and contracts in a direction along the central axis of the protection member DM.

  Further, for example, the protection member DM may be a fluid that is ejected from the lower surface of the second arm A2 along the side surface of the lower projecting portion of the shaft S. The fluid is, for example, air, gas, water, or the like. In this case, the fluid is ejected from the protection member DM to a position lower than the tip of the shaft S. In this case, the protection member DM can be regarded as the fluid of the portion of the injected fluid that covers the side surface of the lower protruding portion of the shaft S. In this case, the protection member DM expands and contracts in the axial direction of the shaft S as the shaft S moves up and down. Further, when the fluid is the protection member DM, the worker, the object X, and the like hardly contact the lower projecting portion of the shaft S due to the pressure of the fluid. As a result, the robot 20 causes the worker to come into contact with a part of the lower projecting part of the shaft S that is covered by the protection member DM (for example, the worker And the object X comes into contact with a part of the lower protruding part of the shaft S that is covered with the protective member DM. (For example, the teaching pendant carried by the worker may come into contact with a portion of the lower protruding portion of the shaft S that is covered by the protection member DM, or the like). Can be suppressed. Further, since the robot 20 is provided with the protection member DM, the robot 20 is provided between the second arm A2 and the portion of the lower projecting portion of the shaft S which is covered by the protection member DM, and the Can be prevented from being pinched by clothes worn by the user, an object X held by the worker, and the like. That is, by providing the protection member DM, the robot 20 can prevent an operator from contacting a part of the shaft S and suppress an object X from contacting a part of the shaft S. Either one or both can be suppressed.

  Next, the configuration of the protection member DM relating to the elasticity of the protection member DM along the radial direction of the protection member DM will be described. For example, the expansion / contraction rate of the protection member DM when the first force acts on the protection member DM along the radial direction of the shaft S is the same as that when the first force acts on the protection member DM along the axis direction of the shaft S. Desirably, it is smaller than the expansion and contraction rate of the protection member DM. In this case, the protection member DM is more effective when the first force acts on the protection member DM along the radial direction of the shaft S than when the first force acts on the protection member DM along the axial direction of the shaft S. It is harder to deform. That is, in this case, the protection member DM does not substantially expand and contract in the radial direction, but expands and contracts in the axial direction. Accordingly, when there is a gap between the protection member DM and the shaft S, the protection member DM comes into contact with the shaft S due to contact with an operator, and the protection member DM contacts with the object X. Contact with the shaft S can be suppressed. As a result, the robot 20 can suppress one or both of the protection member DM and the shaft S from being worn due to the contact between the protection member DM and the shaft S. Here, the first force is an external force of a certain magnitude acting on the protection member DM. Further, the expansion ratio is represented by, for example, a ratio of an expanded length to an unexpanded length, that is, a strain, but is not limited thereto. When the first force is applied to the protection member DM along the radial direction of the shaft S, the expansion and contraction rate of the protection member DM is replaced by the first force applied to the protection member DM along the axial direction of the shaft S. May be equal to or greater than the expansion / contraction rate of the protection member DM in the case where.

  Further, for example, the material of the protection member DM is such that the bending of the protection member DM when the side surface of the protection member DM is pushed toward the shaft S is different from the protection member DM and the shaft S when the force is not applied to the protection member DM. It is desirable that the material be smaller than the width between them. Examples of such a material include acrylic, carbon, and metal. Accordingly, when there is a gap between the protection member DM and the shaft S, the protection member DM comes into contact with the shaft S due to contact with an operator, and the protection member DM contacts with the worker. Contact with the shaft S can be suppressed. As a result, the robot 20 can suppress one or both of the protection member DM and the shaft S from being worn due to the contact between the protection member DM and the shaft S. Instead of this, the material of the protection member DM may be such that the bending of the protection member DM when the side surface of the protection member DM is pushed toward the shaft S is the same as the protection member DM when the force is not applied to the protection member DM. A material having a width equal to or greater than the width between the shaft and the shaft S may be used. Further, for example, the structure of the protection member DM is such that the bending of the protection member DM when the side surface of the protection member DM is pushed toward the shaft S is different from the protection member DM and the shaft S when the force is not applied to the protection member DM. The width may be smaller than the width between the protection member DM and the width between the protection member DM and the shaft S when no force is applied to the protection member DM.

  Due to the above-described materials, structures, and the like, the protection member DM causes the worker to come into contact with the lower projecting portion of the shaft S (for example, the worker contacts the lower projecting portion of the shaft S). And the like, and that the object X comes into contact with the lower projecting portion of the shaft S (for example, the teaching pendant carried by the worker comes into contact with the lower projecting portion of the shaft S). can do. As a result, the robot 20 can work with the worker more safely.

<Modification of protection member DM>
The protection member DM described above is configured to cover a part of the lower protruding portion of the shaft S instead of covering a part of the lower protruding portion of the shaft S, and to include a part of the movable portion A other than a portion to which the end effector is attached together with the lower protruding portion of the shaft S. May be configured to cover a part or all of the part. For example, when the protection member DM covers the whole of the movable part A, the robot 20 moves the worker's finger, clothes worn by the worker, work between the first arm A1 and the second arm A2, and the like. It is possible to prevent the object X or the like held by the person from being caught. In this case, the above-described cover CV may be configured not to be provided on the second arm A2.

  Further, the protection member DM described above may be made of a conductive material. Thereby, the robot 20 can suppress the protection member DM from being charged with static electricity. Further, in this case, the contact detection unit TS may detect the contact between the worker and the movable unit A based on a change in capacitance that occurs when the worker comes into contact with the protection member DM.

  In addition, among the protective members DM described above, the protective member DM made of carbon may have a configuration in which carbon is included in a part of the material, or all parts may be made of carbon.

  Note that the downward direction described above may have a configuration that does not coincide with the direction of gravity. Further, the above-described downward direction may not be the same as the negative direction of the Z-axis in the robot coordinate system RC.

  Further, the contact detection unit TS described above can detect that the worker has contacted the robot 20 among the positions corresponding to the robot 20 instead of the configuration provided between the base B and the installation surface. The structure provided in another position may be sufficient.

  Further, the contact detection unit TS described above may have a configuration including a processor that determines whether or not the worker has contacted the robot 20 based on the contact information. In this case, the contact detection unit TS outputs information indicating the determination result to the robot control device 30. For example, when the external force detected by the contact detection unit TS exceeds a predetermined threshold, the processor determines that the worker has contacted the robot 20.

  In addition, the contact detection unit TS described above is, instead of the force sensor, another sensor that can detect that the worker has contacted the robot 20, such as a torque sensor, an area sensor, or a camera connected to an image processing device. , A device, and the like.

  Further, the cover CV described above may be made of a material having elasticity. In this case, the size of the cover CV changes in accordance with the vertical movement of the shaft S, and continues to cover the entire upper protruding portion of the shaft S.

  The person who may contact the robot 20 described above may be a person other than the worker.

  As described above, the SCARA robot (the robot 20 in this example) according to the embodiment is provided on the base (the base B in this example) and the first axis (the first shaft in this example). A first arm (first arm A1) that rotates around a rotation axis AX1), and a second axis (in this example, a second rotation axis AX2) provided on the first arm and parallel to the first axis. A second arm (in this example, a second arm A2) that pivots in a direction parallel to the second axis with respect to the second arm (in this example, a third rotation in this example) A shaft (in this example, the shaft S) that moves in the axial direction of the axis AX3), and a portion provided on the second arm, and a portion of the shaft from the second arm toward a side opposite to the installation surface on which the base is installed. Protruding site (in this example, A cover (in this example, a cover CV) that covers the upper projecting portion of the shaft S, and a portion of the shaft that projects from the second arm toward the installation surface (in this example, a lower projecting portion of the shaft S). A movable member (movable member A in this example) including a protective member (protective member DM) that covers a part of a part (part), and a person (for example, the worker described above) and an object (in this example, an object X) and a contact detection unit (in this example, a contact detection unit TS) for detecting contact with one or both of the protection member and an output of the contact detection unit (in this example, contact information). A first processor (in this example, a first processor 31) that stops the operation of the movable unit. Thereby, the SCARA robot can work with humans more safely.

  The SCARA robot further includes a second processor (in this example, a second processor 32) that stops the operation of the movable unit based on the output of the contact detection unit, and the second processor has an abnormality in the first processor. A configuration may be used in which the operation of the movable unit is stopped when the error occurs, and the first processor stops the operation of the movable unit when the abnormality occurs in the second processor.

  Further, in the SCARA robot, the protection member is formed when the first force acts on the protection member along the radial direction of the shaft than when the first force acts on the protection member along the axial direction of the shaft. A configuration that is not easily deformed may be used.

  In the SCARA robot, the material of the protection member is such that the bending of the protection member when the side surface of the protection member is pushed toward the shaft is the width between the protection member and the shaft when no force is applied to the protection member. A configuration that is a smaller material than the above may be used.

  In the SCARA robot, the structure of the protection member is such that the bending of the protection member when the side surface of the protection member is pushed toward the shaft is the width between the protection member and the shaft when no force is applied to the protection member. A configuration that is a smaller structure than that may be used.

  In the SCARA robot, a configuration in which the first portion of the protection member is attached to the second arm may be used.

  In the SCARA robot, a configuration in which the first portion is attached to the second arm via a bearing may be used.

  In the SCARA robot, a configuration in which the second portion of the protection member is attached to a shaft may be used.

  In the SCARA robot, a configuration in which the second portion is attached to a shaft via a bearing may be used.

  In the SCARA robot, a configuration in which a part or the whole of the protection member is formed of carbon may be used.

  In the SCARA robot, a configuration may be used in which the protection member covers a part or all of the movable part.

  In the SCARA robot, a configuration is used in which the protection member has conductivity, and the contact detection unit detects contact between the movable unit and a person based on a change in the capacitance of the protection member. Good.

  The SCARA robot is provided on a base, a first arm provided on the base and rotating about a first axis, and a SCARA robot provided on the first arm and rotating about a second axis parallel to the first axis. A second arm, a shaft penetrating through the second arm and moving in the axial direction of a third axis parallel to the second axis with respect to the second arm, and a base provided in the second arm and having a shaft. A cover that covers a portion protruding from the second arm toward a side opposite to the installation surface on which the base is installed, and a protection member that covers a portion of the portion of the shaft that protrudes from the second arm toward the installation surface , A contact detector that detects contact between the protection member and the object (the object X in this example), and a first processor that stops the operation of the movable unit based on an output of the contact detector. And. Thereby, the SCARA robot can work with humans more safely.

  The embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to the embodiments, and changes, substitutions, deletions, and the like can be made without departing from the gist of the present invention. May be done.

DESCRIPTION OF SYMBOLS 1 ... Robot system, 20 ... Robot, 30 ... Robot controller, 31 ... 1st processor, 32 ... 2nd processor, 33 ... Memory, 34 ... Communication part, A ... Movable part, A1: 1st arm, A2 ... 2-arm, AX1: first rotation axis, AX2: second rotation axis, AX3: third rotation axis, B: base, CV: cover, DM: protection member, EG1: first part, EG2: second 2 parts, RC: robot coordinate system, S: shaft, TS: contact detection unit, X: object

Claims (10)

A base,
A first arm provided on the base and rotating about a first axis;
A second arm provided on the first arm and rotating about a second axis parallel to the first axis;
A shaft penetrating the second arm and moving in an axial direction of a third axis parallel to the second axis with respect to the second arm;
A cover provided on the second arm, for covering a part of the part of the shaft that protrudes from the second arm toward a side opposite to an installation surface on which the base is installed;
A protection member that covers a part of a part of the shaft that protrudes from the second arm toward the installation surface,
A movable part comprising:
One or both of a person and an object, and the protection member, a contact detection unit that detects contact between the
A first processor that stops the operation of the movable unit based on an output of the contact detection unit;
SCARA robot equipped with. A second processor that stops the operation of the movable unit based on an output of the contact detection unit,
The second processor, when an abnormality occurs in the first processor, stops the operation of the movable unit,
The first processor stops the operation of the movable unit when an abnormality occurs in the second processor.
The SCARA robot according to claim 1. The protection member is more suitable when the first force acts on the protection member along the radial direction of the shaft than when the first force acts on the protection member along the axial direction of the shaft. Is difficult to deform,
The SCARA robot according to claim 1. A first portion of the protection member is attached to the second arm;
The SCARA robot according to any one of claims 1 to 3. The first portion is attached to the second arm via a bearing,
The scalar robot according to claim 4. A second portion of the protection member is attached to the shaft;
The SCARA robot according to any one of claims 1 to 5. The second portion is attached to the shaft via a bearing;
The SCARA robot according to claim 6. Part or all of the protection member is formed of carbon,
The SCARA robot according to any one of claims 1 to 7. The protection member covers a part or the whole of the movable part,
The SCARA robot according to any one of claims 1 to 8. The protection member has conductivity,
The contact detection unit detects a contact between the movable unit and the person based on a change in capacitance of the protection member.
The SCARA robot according to any one of claims 1 to 9.

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