Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
  • B25J19/00—Accessories fitted to manipulators, e.g. for monitoring, for viewing; Safety devices combined with or specially adapted for use in connection with manipulators
  • B25J19/02—Sensing devices
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
  • G01S3/00—Direction-finders for determining the direction from which infrasonic, sonic, ultrasonic or electromagnetic waves, or particle emission, not having a directional significance, are being received
  • G01S3/78—Direction-finders for determining the direction from which infrasonic, sonic, ultrasonic or electromagnetic waves, or particle emission, not having a directional significance, are being received using electromagnetic waves other than radio waves
  • G01S3/782—Systems for determining direction or deviation from predetermined direction

Definitions

• the present invention relates to a manipulator positioning device and method. More specifically, the present invention relates to a manipulator positioning device and method that can inexpensively and easily detect the relative positions of a manipulator and an object to be operated, and enables intuitive manipulator positioning.
• the touch-up method has been known as one method for determining the position of an object to be manipulated by a manipulator (operation object). Specifically, the position of the tool tip point relative to a coordinate system fixed to the end of the manipulator's arm is determined in advance, and the operator manipulates the tool tip point in advance to align it with the operation object, and then imports the position data to determine the position of the operation object.
• this method has problems with low precision, such as setting errors and alignment errors, and requires the operator to be highly skilled. Another issue is that the tool tip approaches very close to the object, which can easily lead to damage accidents due to interference.
• Another method that has been disclosed is to attach a camera to the tip of a manipulator, move the camera, and detect the position by viewing the object to be operated from multiple positions.
• the accuracy is stable as it is based on camera measurements, and since it is a non-contact measurement, damage accidents due to interference are unlikely to occur.
• there are issues such as the need for calibration and coordinate system linking, which makes the work, including advance preparation, complicated, and requires a large labor burden.
• a manipulator When a manipulator is operated based on information obtained by a camera, information regarding the depth direction is lost from the camera image.
• conventional technologies have been used to position a tool attached to the tip of a manipulator (hereinafter also referred to as an "end effector") to a target position by positioning the manipulator based on images from a camera attached to the tip of the manipulator, installing multiple cameras and estimating the three-dimensional position, or installing markers on the end effector and the object to be operated and calculating the relative position based on the camera images.
• Patent Document 1 discloses a method of improving a type of measuring device that measures an object using a camera attached near the end of a robot's arm, or an alternative position-detecting photodetector, to make it possible to perform three-dimensional position measurement without the need for complicated preparations or a dedicated calibration plate.
• Patent Document 2 also discloses a robot system and calibration method that can capture images of multiple markers, easily and quickly perform the complicated calibration work between camera coordinates and robot coordinates, and reduce work errors.
• the objective of the present invention is to provide a positioning device and a method for positioning a manipulator that can inexpensively and easily detect the relative position between a manipulator and an object to be operated and enable intuitive positioning of the manipulator.
• the present invention provides a manipulator positioning device and a manipulator positioning method characterized by the following.
• the manipulator positioning device of the present invention comprises a light source attached to the tip of the manipulator, a first target that receives the irradiation light emitted from the light source, and a second target that receives the irradiation light emitted from the light source, and is characterized in that the first target and the second target are at different distances from the light source.
• a light source emitted from the tip side of the manipulator is used, and information on the relative positions of the manipulator and the target can be obtained based on the light receiving state of two targets at different distances from the light source.
• the irradiated light is emitted so as to be parallel to the axis of advancement of the end effector at the tip of the manipulator.
• the traveling axis of the end effector and the optical axis of the irradiated light are parallel. Therefore, by aligning the target with the distance between the two axes equal and placing it near the object to be operated, and by setting the light receiving state for the target plane to a predetermined state, the axis of the end effector (position in the planar direction) can be aligned with the object to be operated. At this time, by operating the manipulator in the direction of the traveling axis of the end effector, highly accurate operation of the object to be operated is possible.
• the irradiated light is emitted as guide light having a characteristic shape. According to this feature, it becomes easy to recognize the deviation in coordinates around the axis of travel of the end effector from the light receiving state of the target that receives the guide light, thereby making it possible to improve the accuracy when operating the manipulator in the axial direction of the end effector.
• the first target and the second target are provided with a means for recognizing a receiving position of the irradiated light. According to this feature, it becomes easy to confirm, from the state in which the irradiated light is received at the target, whether the positional relationship between the axis of the end effector at the tip of the manipulator and the target is parallel or whether there is an angular deviation, thereby making it possible to improve the accuracy when operating the manipulator in the axial direction of the end effector.
• one embodiment of the manipulator positioning device of the present invention is characterized in that the light source includes a first light source that emits irradiation light parallel to the axis of travel of the end effector at the tip of the manipulator, and a second light source that emits irradiation light inclined from the axis of travel of the end effector at the tip of the manipulator.
• the light source includes a first light source that emits irradiation light parallel to the axis of travel of the end effector at the tip of the manipulator, and a second light source that emits irradiation light inclined from the axis of travel of the end effector at the tip of the manipulator.
• the manipulator positioning method of the present invention for solving the above problems includes a light emitting step of emitting light from a light source attached to the tip of the manipulator, and a light receiving step of receiving the light at a first target and a second target, wherein the first target and the second target are at different distances from the light source.
• this manipulator positioning method it is possible to obtain information on the relative positions of the manipulator and the target by emitting irradiation light from a light source attached to the tip side of the manipulator and receiving the light on two targets at different distances from the light source. This makes it possible to inexpensively and easily detect the relative positions of the manipulator and the object to be operated without the need for attaching a new camera or image processing.
• the operator can perform operations related to positioning while visually checking the light receiving state of the target, intuitive positioning of the manipulator is possible.
• remote manipulator operation teleoperation
• the present invention provides a positioning device and a method for positioning a manipulator that can inexpensively and easily detect the relative position between the manipulator and an object to be operated and enable intuitive positioning of the manipulator.
• FIG. 1 is a schematic explanatory diagram showing a positioning device for a manipulator in a first embodiment of the present invention
• FIG. 2 is a schematic explanatory diagram showing an example of the structure of a first target and a second target in the first embodiment of the present invention.
• 1 is a schematic explanatory diagram showing a light receiving state of a target in a first embodiment of the present invention (a state in which the axis of the irradiated light and the axis of the end effector are deviated from the vertical axis).
• FIG. FIG. 2 is a schematic explanatory diagram showing another aspect relating to the structures of the first target and the second target in the first embodiment of the present invention.
• FIG. 11 is a schematic explanatory diagram showing a manipulator positioning device according to a second embodiment of the present invention.
• FIG. 11 is a schematic explanatory diagram showing the positional relationship between a first irradiation light, a second irradiation light, and a target in a second embodiment of the present invention.
• manipulator positioning device and a manipulator positioning method according to the present invention will be described in detail with reference to the drawings.
• the manipulator positioning method in the present invention is to be substituted for the description of the manipulator positioning device in the present invention.
• manipulator positioning device and manipulator positioning method described in the embodiments are merely examples provided to explain the manipulator positioning device and manipulator positioning method according to the present invention, and are not limited thereto.
• the manipulator positioning device of the present invention is one of the auxiliary devices provided for the manipulator.
• the manipulator positioning device of the present invention may be attached to the manipulator so as to be attachable and detachable thereto, or may be attached to the manipulator so as to be partly integrated therewith.
• the manipulator in this invention refers to an upper limb robot, particularly a robot arm portion.
• it is something that performs various movements equivalent to those of a human arm, and is usually made up of a combination of a rotatable joint portion, which corresponds to the joints of the shoulder, elbow, wrist, etc. in a human arm, and a rod-shaped link portion.
• the end effector refers to a general tool attached to the tip of a manipulator. In other words, it corresponds to a human palm and refers to a part that controls various processing-related actions and tasks such as "grabbing, screwing, welding, painting, cutting, and polishing." For example, in the action of "grabbing,” there are types that hold an object by pinching it with two or more claws, and types that adsorb an object by vacuum pressure or magnets.
• end effectors that have functions specialized for the applications of the above-mentioned various processing-related actions and tasks. In the following embodiment, an end effector that performs a "grasping" operation using a gripping method will be described as an example.
• an end effector 20 equipped with a gripping portion 21 will be described as an example in which the end effector grasps from directly above, but the present invention is not limited to this.
• the operation object also called the "workpiece” is the object on which various operations or tasks are performed by the end effector. For example, if the end effector performs an operation related to "grasping," the operation object refers to the object to be grasped.
• the type of operation object differs depending on the type of manipulator (the content of the task performed by the end effector). For example, if the manipulator is a welding robot, the operation object is an object to be welded, and if the manipulator is a painting robot, the operation object is an object to be painted.
• FIG. 1 is a schematic explanatory diagram showing a manipulator positioning device according to a first embodiment of the present invention.
• the manipulator positioning device in this embodiment is attached to a manipulator 10 having a gripping portion 21 as an end effector 20.
• the gripping portion 21 is for gripping an operation target 30, and it is sufficient if it has a function of gripping the operation target 30, and there is no particular limitation on the specific structure.
• the positioning device of the manipulator in this embodiment will also be referred to simply as the "positioning device (positioning device 40A)" hereinafter.
• the positioning device 40A in this embodiment includes a light source 41 that emits irradiation light 42, a first target 43, and a second target 44.
• a light source 41 that emits irradiation light 42
• a first target 43 a target that emits irradiation light 42
• a second target 44 a target that emits irradiation light 42
• first target 43 and the second target 44 they may be simply referred to as "targets.”
• the light source 41 in this embodiment is attached to the tip of the manipulator 10 (end effector 20), and emits irradiation light 42 to targets (a first target 43 and a second target 44) described below.
• the mounting position of the light source 41 is not important as long as the state in which the irradiated light 42 is received on the target can be confirmed (visually confirmed) from the outside.
• the light source 41 is provided at a position that is a certain distance away in the horizontal direction (X-axis direction in FIG. 1 ) from the axis of the traveling direction of the end effector 20 (hereinafter referred to as the Z-axis) and that can emit the irradiated light 42 downward toward the base of the end effector 20.
• the axial distance between the traveling axis of the end effector and the optical axis of the irradiated light is a guide for the distance to a second target 44 that is installed near the operation target 30 and the irradiation position is aligned.
• the light source 41 may be any light source such as a light bulb that can irradiate visible light, but is preferably a laser light source, which makes the irradiated light 42 a laser beam that has the characteristics of good linearity, no dispersion, and high light intensity, thereby improving the accuracy of the degree of matching when aligning on the target using the irradiated light 42 and also improving the visibility for the operator.
• a laser light source which makes the irradiated light 42 a laser beam that has the characteristics of good linearity, no dispersion, and high light intensity, thereby improving the accuracy of the degree of matching when aligning on the target using the irradiated light 42 and also improving the visibility for the operator.
• Specific examples of the laser light source used as the light source 41 in this embodiment include semiconductor lasers, solid-state lasers, and gas lasers having a light source with a wavelength visible to the naked eye.
• the light source 41 preferably emits the irradiated light 42 as the guide light.
• the guide light in this embodiment refers to the irradiated light 42 having a characteristic shape.
• a cross-shaped slit is provided below the light source 41 to make the irradiated light 42 have a cross-shaped shape. This allows the cross-shaped light to be received on a plane perpendicular to the optical axis.
• the lines that appear on a plane perpendicular to the optical axis due to received light will be referred to as bright lines, and in particular, the lines that appear on the first target 43 described below will be referred to as bright lines 46a, and the lines that appear on the second target 44 will be referred to as bright lines 46b.
• the "characteristic shape” referred to here can be any shape as long as it allows the center point of the optical axis to be recognized, is perpendicular to the Z axis, which is the direction of light travel, and allows the deviation of coordinates around the axis and its direction to be recognized on a plane including the X and Y axis directions.
• it is shown as a cross in Figure 1, it does not have to be a cross, and it could be, for example, three axes spaced 120 degrees apart, or it could be a square or equilateral triangle. However, it is simplest to use a cross shape that intersects at right angles.
• the positioning device 40A in this embodiment is provided with targets (a first target 43 and a second target 44) that receive the irradiation light 42 emitted from the light source 41. Then, by grasping the light receiving state of the first target 43 and the second target 44, information on the relative position between the manipulator and the targets is acquired, and it becomes possible to detect the relative position between the manipulator and the operation target.
• targets a first target 43 and a second target 44
• the first target 43 and the second target 44 are arranged so that they are different distances from the light source 41.
• “different distances from the light source (light source 41)” includes not only different distances in one axial direction (for example, only the Z-axis direction) but also different distances taking into account multiple axial directions (magnitude of a plane vector or a spatial vector).
• the positional relationship between the first target 43 and the second target 44 may be such that there are parts that are different distances from the light source 41, and includes not only those in which the first target 43 and the second target 44 are spatially separated but also those in which there are parts that overlap. The reason for arranging the two targets at different distances from the light source 41 is to allow the user to visually and intuitively grasp the positional relationship in the depth direction of the Z axis.
• first target 43 and the second target 44 need only have a surface on which the illumination light 42 emitted from the light source 41 is received and bright lines (bright lines 46a, 46b) appear, and there are no particular limitations on the structure of the first target 43 and the second target 44 themselves. More specifically, the first target 43 and the second target 44 may be separate flat or three-dimensional structures, or the first target 43 and the second target 44 may be provided within a single structure.
• FIG. 2 is a schematic explanatory diagram showing an example of the structure of the first target 43 and the second target 44 in an embodiment of the present invention.
• an example of the target in this embodiment is a flat plate that receives the irradiated light 42.
• the first target 43 and the second target 44 each have a plane perpendicular to the Z axis, and each is an independent structure made of a flat plate.
• the first target 43 and the second target 44 are set at different distances from the light source 41 in the vertical direction (Z-axis direction), with the first target 43 being closer to the light source.
• the first target 43 is fixed vertically above the second target 44. It is preferable that the first target 43 has a smaller area than the second target 44. This is so that the shadow of the irradiated light 42 hitting the first target 43 is projected onto the flat surface of the second target 44.
• the target material may also be a transparent acrylic plate or polycarbonate plate.
• the first target 43 and the second target 44 include a means for recognizing the position at which the irradiated light 42 is received. More specifically, by designing the shapes of the first target 43 and the second target 44 themselves, it is possible to make it easier to recognize (visually recognize) the receiving position of the irradiated light 42, as well as to provide a marker 45.
• the marker 45 in this embodiment is a characteristic shape drawn on the surface of the target.
• the "characteristic shape” drawn here refers to a shape that allows the center point of the optical axis to be recognized, is perpendicular to the Z axis, which is the traveling direction of the light, and allows the deviation of coordinates around the axis and its direction to be recognized on a plane including the X axis and Y axis directions, as in the case of the guide light.
• the marker 45 is shown as a cross-shaped line, and the first target 43 and the second target 44 are provided with markers 45 of the same shape, but this is not limited to this.
• Other examples of the marker 45 may include, for example, three axial lines spaced at 120 degree intervals, or a shape combining a plurality of squares, equilateral triangles, sectors, etc.
• the shapes of the marker 45 provided on the first target 43 and the marker 45 provided on the second target 44 may be different. However, it is simple to provide the marker 45 in the shape of a cross-shaped line that intersects at right angles and the same shape on the first target 43 and the second target 44.
• the object to be operated 30 (in this case, the object to be grasped) is placed at a position equal to the distance (axial distance) between the already-identified axis of travel of the end effector 20 and the optical axis of the light 42 illuminated from the light source 41 from the center point of the characteristic shape (in this case, a cross-shaped line) of the second target 44 plane. Then, irradiation light 42 (guide light) is emitted from the light source 41 and received by targets (a first target 43 and a second target 44). Specifically, the example shown in FIG. 1 was carried out under the following conditions.
• FIG. 3 is a schematic explanatory diagram showing a light receiving state of a target in the first embodiment of the present invention.
• FIG. 3 shows a state in which the axis of the irradiated light 42 and the axis of the end effector 20 are deviated from the vertical axis
• FIG. 1 shows a state in which the axis of the irradiated light 42 and the axis of the end effector 20 are parallel to the vertical axis.
• the manipulator 10 is operated to manipulate the position of the end effector 20 so that the bright lines 46a, 46b (in this case, cross lines) of the irradiated light 42 (guide light) coincide with the positions of the markers 45 of the first target 43 and the second target 44 (in this case, cross-shaped lines), and it is confirmed that the center point of the guide light coincides with the center point of the first target and the second target.
• the bright lines 46a, 46b in this case, cross lines
• the irradiated light 42 guide light
• the center point of the guide light coincides with the center point of the first target and the second target.
• Whether the axis of the end effector 20 is tilted from the vertical direction can be intuitively grasped from the positional relationship of the irradiated light 42 (guide light) on the marker 45 of the first target 43 and the second target 44, in other words, the position of the bright lines 46a, 46b relative to the marker 45.
• the positional relationship of the irradiated light 42 (guide light) on the marker 45 of the first target 43 and the second target 44 in other words, the position of the bright lines 46a, 46b relative to the marker 45.
• the direction of tilt and deviation can be grasped from the situation related to the positional relationship between the targets and the guide light.
• both the first target 43 and the second target 44 are shown as flat plate-shaped structures, but either one or both may be three-dimensional structures. Also, as described above, the first target 43 and the second target 44 are not limited to being arranged as separate structures as shown in FIG. 2.
• Fig. 4 is a schematic explanatory diagram showing another aspect of the structure of the first target 43 and the second target 44 in the embodiment of the present invention.
• Fig. 4A is a perspective view
• Fig. 4B is a plan view of the structure 47 in Fig. 4A when viewed from the light source 41 side.
• another embodiment of the first target 43 and the second target 44 is provided within one structure. More specifically, in a three-dimensional structure 47 that is a quadrangular pyramid with an apex e and a base of a quadrangle abcd, the side aec is the first target 43 and the side bed is the second target 44. Note that the first target 43 and the second target 44 shown in Fig. 4 have different distances from the light source 41 in that the magnitudes of the spatial vectors starting from the light source 41 are different.
• the axis of the irradiated light 42 and the axis of the end effector 20 are deviated from the vertical axis, in other words, the relative position of the manipulator 10 (end effector 20) and the operation target 30 is in a position unsuitable for operation by the gripping unit 21 of the end effector 20.
• the structure 47 shown in FIG. 4 may be designed so that the sides connecting the vertex e to each point abcd have a predetermined width (a surface having a predetermined area). This makes it even easier to recognize (visualize) the light receiving position of the irradiated light 42 for the side aec of the first target 43 and the side bed of the second target 44.
• Fig. 4 shows a flat base 48 on which the structure 47 having the first target 43 and the second target 44 is placed, but this base 48 may be omitted. Furthermore, Fig. 4 shows a marker 48a on the surface of the base 48 to make it easier to grasp the positional relationship between the first target 43 and the second target 44 and the emission lines 46a and 46b, but this marker 48a may also be omitted.
• FIG. 5 is a schematic explanatory diagram showing a manipulator positioning device according to a second embodiment of the present invention.
• the manipulator positioning device 40B in this embodiment uses, as the light source 41 of the positioning device 40A in the first embodiment, a first light source 41a that emits a first irradiation light 42a parallel to the traveling axis of the end effector 20 and a second light source 41b that emits a second irradiation light 42b inclined from the traveling axis of the end effector 20. That is, the manipulator positioning device 40B in this embodiment is obtained by adding the second light source 41b to the positioning device 40A in the first embodiment.
• the positioning device 40B of the manipulator in this embodiment will be hereinafter simply referred to as "positioning device 40B.” Also, a description of the same configuration as in the first embodiment will be omitted.
• the positioning device 40B in this embodiment is provided with a first light source 41a (light source 41 in the first embodiment) that emits a first irradiation light 42a parallel to the axis of travel of the end effector 20, as well as a second light source 41b that emits a second irradiation light 42b inclined from the axis of travel of the end effector 20, thereby causing the target to receive the two irradiation lights 42a and 42b. Then, by checking the light receiving state of the target at this time, it is possible to obtain information about the distance in the direction of the advancing axis of the end effector 20.
• the first light source 41a and the second light source 41b are both attached to the tip of the manipulator 10 (end effector 20) and emit irradiation light 42a and 42b, respectively, to the target. At that time, it is preferable that the inclined second irradiation light 42b intersects with the first irradiation light 42a at one point on the optical axis to have an intersection point.
• the position and inclination direction of the second light source 41b are not particularly limited as long as the second irradiation light is received by the target, but for example, as shown in FIG.
• the second light source 41b can be installed at a position along the Y-axis direction or the X-axis direction from the first light source 41a so that the second irradiation light hits the Y-axis direction line or the X-axis direction line on the target (in this case, the crosshairs).
• the first light source 41a and the second light source 41b may have different emission angles with respect to the target, and may be the same as the light source 41 described above.
• the irradiation lights 42a and 42b emitted from the first light source 41a and the second light source 41b may have different wavelengths (colors) in order to improve the visibility of the irradiation lights 42a and 42b.
• the first light source 41a and the second light source 41b may emit the irradiation lights 42a and 42b as guide lights having a characteristic shape, or the second irradiation light 42b may be a point light source.
• FIG. 6 is a schematic explanatory diagram showing the positional relationship between the first and second irradiation lights and the target in this embodiment.
• the angle at which the irradiated lights 42a and 42b intersect and the intersecting position are constant. Therefore, information regarding the distance (height) between the end effector 20 and the operation target 30 can be obtained from the light receiving state when the irradiated lights 42a and 42b are received by the target.
• the inclination angle of the second light source 41b adjustable, it is possible to change the angle at which the irradiated lights 42a and 42b intersect and the intersecting position (length from the first light source 41a) to any value.
• the following positioning means can be taken.
• the operations related to positioning by the positioning device 40B shown in FIG. 5 those related to the distance (height) between the end effector 20 and the operation target object 30 will be described by way of an example.
• the distance (height) between the end effector 20 and the operation target 30 is the length (a settable fixed value) from the first light source 41a to the intersection of the irradiated lights 42a and 42b.
• the emission angle emitted from the second light source 41b can be set in advance so that the distance between the end effector 20 and the object to be operated 30 is a predetermined value (such as a height appropriate for operation).
• a predetermined value such as a height appropriate for operation.
• the example in FIG. 5 was carried out under the following conditions. Inclination angle of second irradiation light 42b with respect to first irradiation light 42a: 18 degrees. A point light source of a semiconductor laser was used as the second light source 41b.
• the manipulator positioning device and method of the present invention can be applied to various industrial robots used indoors and outdoors, as well as to transport devices such as cranes, etc. In particular, it is suitable for use in cases where remote manipulator operation (teleoperation) is required. Furthermore, the manipulator positioning device and method of the present invention do not require the installation of a new camera or cable on the manipulator, and can be suitably used, for example, in harsh environments where cameras are prone to deterioration.
• Manipulator 20 End effector 21 Grip unit 30 Operation target 40A Positioning device 40B Positioning device 41 Light source 41a First light source 41b Second light source 42 Irradiation light 42a First irradiation light 42b Second irradiation light 43 First target 44 Second target 45 Marker 46a Bright line (first target side) 46b Bright line (second target side) 47 Structure 48 Base 48a Marker

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• 2024
  • 2024-04-03 JP JP2025513164A patent/JPWO2024210161A1/ja active Pending
  • 2024-04-03 WO PCT/JP2024/013859 patent/WO2024210161A1/ja not_active Ceased

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