JP2013173191A - Robot apparatus, robot control apparatus, robot control method, and robot control program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To save effort when an object is rotated.SOLUTION: A robot apparatus includes a robot body 10 that holds an object to convey it to a goal position; an imaging device that images a visual field including the goal position and the object held by the robot body; a correspondence relation obtaining portion 54 that obtains a correspondence relation between a coordinate system of an image captured by the imaging device and a coordinate system of the robot body 10; a coordinate transformation section 55 that transforms a position designated in the image captured by the imaging device to a designated position in a robot coordinate system, on the basis of the correspondence relation; and a moving control portion 58 that controls the robot body 10 to the designated position in the robot coordinate system so as to move the rotation center position of the object held by the robot body 10, and rotates the object around the rotation center position.

Description

  The present invention relates to a robot apparatus, a robot control apparatus, a robot control method, and a robot control program.

  When a part (for example, a gear) is gripped by a robot hand and the part is assembled to another part installed on a stand or the like, the part may be rotated and assembled. As an example of rotating and assembling parts, there is a gear train assembly. In the gear train assembly, the gear needs to be fitted with another gear by rotating the gear while passing the gear through the shaft. Here, if the rotation center position (hereinafter referred to as the rotation center position) is not accurate when the gear is rotated, the gear and the shaft may come into contact with each other, which may damage or damage the gear or the shaft.

  Therefore, conventionally, the hand position of the robot hand (hereinafter referred to as the robot hand position) is actually measured from the center position of the robot hand. Then, the robot rotates the component based on the measured value with the rotation center position of the component as an axis.

  Further, in Patent Document 1, the posture and position coordinates of a part are detected by a visual sensor, and the detected position coordinates are converted from the detection position coordinate system of the visual sensor to the tool position coordinate system of the articulated robot. A tool position correcting method for an articulated robot is disclosed in which a tool is moved from a direction corresponding to the posture of the component to the tool position coordinates of the obtained component, and the component is operated by the tool that takes the reference work posture.

JP 2006-82171 A

  In Patent Document 1, it is necessary to check the rotation center position of a component (for example, the center position of a gear) as a relative position from the robot hand position using a robot hand model and a component model. Therefore, every time the robot hand changes or the gripped part changes, it is necessary to measure the rotation center position. However, there is a problem that this measurement work is very time-consuming.

  Therefore, the present invention has been made in view of the above problems, and provides a robot apparatus, a robot control apparatus, a robot control method, and a robot control program that can reduce the trouble of rotating an object.

(1) The present invention has been made in view of the above circumstances, and one aspect of the present invention includes a robot body that grips an object and conveys the object to a goal position, and the goal position and the object that the robot body grips. An imaging unit that captures an image in a field of view, a correspondence acquisition unit that acquires a correspondence between a coordinate system of an image captured by the imaging unit and a coordinate system of the robot body, and a correspondence acquired by the correspondence acquisition unit A coordinate conversion unit that converts the designated position in the image captured by the imaging unit to a designated position in the robot coordinate system, and the robot coordinates obtained by the coordinate conversion by the coordinate conversion unit The robot body is controlled to move the rotation center position of the object held by the robot body to a specified position in the system, and the object is rotated around the rotation center position. A movement control unit for a robot apparatus, characterized in that it comprises a.
According to this configuration, the robot apparatus controls the robot body to move the rotation center position of the object held by the robot body to a position specified in advance in the image captured by the imaging unit. As a result, even if the rotation center position of the object changes each time the object is gripped, the robot apparatus moves to the center position of the image by moving the rotation center position of the object to the designated position in the image. The object can be rotated about the center position of the image as an axis. As a result, the robot apparatus does not need to measure the rotation center position of the gripped object, so that it is possible to reduce time and effort when rotating the component.

(2) In the robot apparatus described above, according to one aspect of the present invention, the designated position in the image is a center of the image.
According to this configuration, since the center position of the image is less distorted in the optical system and the center position of the image accurately indicates the position of the subject, the robot apparatus can accurately determine the position of the object with the center of the image by simple processing. It can be moved to a position.

(3) In the robot apparatus described above, according to one aspect of the present invention, the rotation center position in the robot coordinate system obtained by coordinate conversion by the coordinate conversion unit and the robot body in the robot coordinate system grip A post-rotation position calculation unit that calculates a rotated robot hand position based on the robot hand position indicating the position of the robot, and the movement control unit moves to the robot hand position calculated by the post-rotation position calculation unit. The robot hand is rotated about a designated position in the robot coordinate system so that the robot hand moves.
According to this configuration, since the robot device rotates the hand of the robot around the specified position in the robot coordinate system, even if the rotation center position of the object changes every time the object is gripped, the object is moved to the rotation center position. Can be accurately rotated around the axis.

(4) In the robot apparatus described above, one aspect of the present invention is a robot hand position calculation unit that calculates the robot hand position in the robot coordinate system based on each angle of an arm joint included in the robot body. It is characterized by providing.
According to this configuration, the robot apparatus can calculate the robot hand position after the rotation based on the calculated robot hand position in the robot coordinate system, so the robot hand is moved around the designated position in the robot coordinate system. Can be rotated.

(5) One aspect of the present invention is a robot control apparatus that controls a robot body that grips an object and conveys the object to a goal position, and includes a coordinate system of an image captured by the imaging unit and a coordinate system of the robot body. A corresponding relationship acquisition unit that acquires the corresponding relationship, and coordinate conversion of the specified position in the image captured by the imaging unit to a specified position in the robot coordinate system based on the corresponding relationship acquired by the corresponding relationship acquisition unit A coordinate conversion unit that controls the robot main body to move the rotation center position of the object held by the robot main body to a specified position in the robot coordinate system obtained by the coordinate conversion performed by the coordinate conversion unit And a movement control unit that rotates the object around the rotation center position.
According to this configuration, the robot control device controls the robot body to move the rotation center position of the object held by the robot body to a position designated in advance in the image captured by the imaging device. Thereby, even if the rotation center position of the object changes every time the object is gripped, the robot control device moves the rotation center position of the object to the designated position in the image, thereby Can be obtained. As a result, the robot control apparatus can reduce the trouble of measuring the rotation center position of the grasped object.

  (6) One aspect of the present invention is a robot control method executed by a robot control device that controls a robot body that grips an object and conveys the object to a goal position. The coordinate system of an image captured by an imaging device and the robot Based on the correspondence acquisition procedure for acquiring the correspondence with the coordinate system of the main body and the correspondence acquired by the correspondence acquisition procedure, the designated position in the image picked up by the imaging device is represented by the robot coordinate system. A coordinate conversion procedure for converting the coordinates to the designated position in the position, and the rotation center position of the object gripped by the robot body to the designated position in the robot coordinate system obtained by the coordinate transformation by the coordinate transformation procedure And a movement control procedure for controlling the robot body so as to rotate the object about the rotation center position. It is a Tsu door control method.

  (7) According to one aspect of the present invention, a computer of a robot control device that controls a robot main body that grips an object and conveys the object to a goal position is provided with a coordinate system of an image captured by the imaging device and a coordinate system of the robot main body. Based on the correspondence acquisition step for acquiring the correspondence and the correspondence acquired by the correspondence acquisition step, the specified position in the image captured by the imaging device is coordinate-converted to the specified position in the robot coordinate system. The robot body to move the rotational center position of the object gripped by the robot body to the designated position in the robot coordinate system obtained by the coordinate transformation in the coordinate transformation step. And a movement control step for rotating the object around the rotation center position. Is a control program.

It is a block diagram showing the functional structure of the robot apparatus which is embodiment of this invention. In the same embodiment, it is the figure which represented typically a robot apparatus being installed in the assembly manufacturing line of a factory, and a robot main body performing the assembly operation of an assembly component. It is a top view which shows operation | movement of the holding part which concerns on the same embodiment. In the embodiment, in the wheel train assembly of a spur gear, it is the figure which represented typically the process in which a spur gear is attached to the axis | shaft of a base. It is a schematic block diagram showing the structure of the position detection apparatus which concerns on the same embodiment. It is a schematic block diagram showing the structure of the robot control apparatus which concerns on the same embodiment. It is a figure for demonstrating the process of the robot control apparatus in the embodiment. It is a figure which shows the relationship between the holding part before rotation in the same embodiment, and the holding part after rotation. It is a flowchart which shows the 1st example of the process in which a robot apparatus attaches components to an axis | shaft. FIG. 10 is a flowchart showing an example of details of the processing in step S101 in FIG. It is a flowchart which shows the 2nd example of the process in which a robot apparatus attaches components to an axis. It is a schematic diagram of a gripping part gripping and rotating other parts and assembling them. It is a general | schematic external view of the robot apparatus in 2nd Embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing a functional configuration of a robot apparatus 1 according to an embodiment of the present invention. The robot apparatus 1 is an apparatus that conveys a part to a target position by visual feedback control and assembles an assembly part. The component in the present embodiment is a precision component (for example, an ultra-small gear) that constitutes an assembly component incorporated in a small electronic device or a precision device.
As shown in the figure, the robot apparatus 1 includes a robot body 10, an imaging device (imaging unit) 20, a position detection device 30, and a robot control device (robot control unit) 50.

  In the robot apparatus 1, the imaging apparatus 20 captures an image of a part gripped by the robot body 10, and the position detection apparatus 30 analyzes an image captured by the imaging apparatus 20 and detects a detection target defined corresponding to the part. Process. Here, the detection target is a part of a part. The robot control device 50 controls the robot body 10 so that the detection target detected by the position detection device 30 is moved to the target position. The robot body 10 conveys the part under the control of the robot controller 50 and assembles the assembly part. Each configuration of the robot apparatus 1 will be described with reference to FIG.

  FIG. 2 is a diagram schematically showing a state in which the robot apparatus 1 is installed in an assembly production line of a factory, and the robot body 10 of the robot apparatus 1 is performing assembly work of assembly parts. In the assembly production line shown in the figure, a robot body 10 and an imaging device 20 in the robot apparatus 1 and a conveyor 100 in which a plurality of assembly parts of the same type being assembled are arranged side by side are installed.

This figure is a diagram immediately before the robot body 10 starts the operation of fitting the component 220b to the shaft 210b. In the figure, the shaft 210b is positioned in advance by the conveyor 100 so that the long axis of the shaft 210b having an extremely fine shaft diameter is positioned on the optical axis of the imaging device 20. As an example, the robot apparatus 1 may control the conveyor 100 so that the long axis of the axis 210b is positioned on the optical axis of the imaging apparatus 20 when the component 220b is fitted into the axis 210b. Thereby, the robot apparatus 1 can make the end surface opposite to the surface joined to the base 200 of the shaft 210b be positioned at the center of the image captured by the imaging device 20.
In the figure, the position detection device 30 and the robot control device 50 are not shown. Further, the scales of parts, structures, and the like in the figure are different from actual ones in order to clarify the figure (the same applies to FIGS. 3 and 4 described later).

The robot body 10 includes a support base 10a fixed to the ground, an arm part 10b connected to the support base 10a so as to be capable of turning and bending, and a hand part connected to the arm part 10b so as to be rotatable and swingable. 10c and the holding part 10d attached to the hand part 10c. The robot body 10 holds the object so that it can be conveyed to the goal position.
The robot body 10 is, for example, a 6-axis vertical articulated robot, and has a 6-axis degree of freedom by a coordinated operation of the support base 10a, the arm unit 10b, and the hand unit 10c. The position and orientation can be changed freely. The robot body 10 moves one or a combination of the arm unit 10b, the hand unit 10c, and the gripping unit 10d under the control of the robot control device 50.
Note that the degree of freedom of the robot body 10 is not limited to six axes, and for example, the degree of freedom may be seven axes. Moreover, you may install the support stand 10a in the place fixed with respect to the grounds, such as a wall and a ceiling.

  The grip portion 10d of the robot body 10 grips the component 220b. The component 220b is a precision component as described above, and is, for example, a spur gear provided with a fine shaft hole. In the present embodiment, when a specific example of the component 220b is shown, a spur gear having a fine shaft hole will be described as an example.

The conveyor 100 has a horizontal movable mounting table, and arranges a plurality of assembly parts of the same type being assembled on the movable mounting table and conveys them in the direction of arrow A. Each assembly component is a base 200 provided with a shaft 210a having an extremely thin shaft diameter and a shaft 210b having an extremely thin shaft diameter. The base 200 has a surface that is parallel to the horizontal plane when placed on the movable mounting table. The shaft 210 a or the shaft 210 b is provided on the surface so that the axial direction thereof is perpendicular to the surface of the base 200. The plurality of assembly parts are aligned on the movable mounting table so that a line connecting the center points of the open ends of the respective axes 210 is a straight line B extending in the direction of arrow A.
In the assembly production line shown in FIG. 2, the robot apparatus 1 performs an operation of attaching the component 220a or 220b to the assembly component such that the shaft 210a or the shaft 210b of the assembly component penetrates the shaft hole of the component (spur gear) 220a or 220b. Is to do.

The imaging device 20 captures an image including the goal position (for example, the axis 210b) and the object (for example, the component 220b) gripped by the robot body 10 in the visual field. The imaging device 20 is, for example, a video camera device that captures images at a frame rate of 30 frames / second (fps; frame per second), 120 frames / second, 200 frames / second, or the like. The imaging device 20 is fixedly installed at a position above the movable mounting table of the conveyor 100 where the imaging direction is vertically downward and the optical axis of a lens optical system (not shown) substantially intersects the straight line B. In FIG. 2, illustration of a structure and the like for fixing the imaging device 20 is omitted.
When photographing with the imaging apparatus 20, the conveyor 100 has the axis 210 a or the axis 210 b substantially below the imaging apparatus 20, that is, the optical axis of the lens optical system and the axis 210 substantially coincide with each other for each of a plurality of arranged assembly parts. The operation of the movable mounting table is stopped at the position. For example, when the operation of the movable mounting table is stopped, the imaging device 20 captures the goal position and the component 220b as subjects in accordance with the imaging request command supplied from the position detection device 30, and obtains the image by this imaging. The obtained image data is supplied to the position detection device 30.

The position detection device 30 operates in the fine detection mode after operating in the coarse detection mode.
In the coarse detection mode, for example, a marker region (hereinafter also simply referred to as a marker) provided on the component 220b is a detection target, the position detection device 30 detects the marker, and the axis center of the axis 210b that is the target position. Is a mode of processing for controlling to move the marker to a position including (marker goal position).
In the fine detection mode, for example, an area of a target (for example, a shaft hole of a spur gear) (hereinafter also simply referred to as a target) that is a reference part of alignment provided in the component 220b is set as a detection target, and position detection is performed. The apparatus 30 detects the target in the marker area, and moves the reference position of the target (center position of the shaft hole of the spur gear) to the position (target goal position) of the axis 210b that is the target position. This is the mode of processing to be controlled.

  In the coarse detection mode, the processing load is reduced and the processing speed is increased by relatively reducing the alignment accuracy. On the other hand, in the fine detection mode, the alignment accuracy is made higher than that in the coarse detection mode, and the processing speed is made slower than that in the coarse detection mode. However, in the fine detection mode, the detection area of the target is limited to the area of the marker, so that the influence of the low processing speed is extremely small.

In the coarse detection mode, the position detection device 30 takes in the image data supplied from the imaging device 20, and detects a marker provided on the component 220b from the image by template matching processing of the image with the search region as the entire image, for example. . Then, the position detection device 30 generates a robot control command for moving the detected marker to the marker goal position, and supplies it to the robot control device 50.
Template matching is one of known object detection methods, for example, by scanning a search target image with a template image and calculating a sum of absolute values of luminance differences between the two images or a square sum of luminance differences. The similarity is obtained, and the object is detected according to the similarity.

In the fine detection mode, the position detection device 30 takes in the image data supplied from the imaging device 20, and performs template matching processing of the image in which the search region is limited to the marker region from the limited region of the image to the part 220b. Detect the target (spur gear shaft hole). Then, the position detection device 30 generates a robot control command having a content for moving the detected reference position of the target (the center position of the shaft hole of the spur gear) to the target goal position (for example, the position of the axis center of the shaft 210b). To the robot controller 50.
Further, when the position detection device 30 takes in the robot control status supplied from the robot control device 50, the position detection device 30 supplies an imaging request command to the imaging device 20 according to the content of the robot control status.

The robot control device 50 takes in the robot control command supplied from the position detection device 30, and based on the robot control command, any one of the arm portion 10b, the hand portion 10c, and the grip portion 10d of the robot body 10 is obtained. Or control the operation of the combination.
In addition, after controlling the robot body 10, the robot control device 50 supplies the position detection device 30 with a robot control status including information indicating whether the control is successful.

FIG. 3 is a plan view showing the operation of the grip portion 10d according to the embodiment. In the figure, the gripping part 10 d has a main body part 11 and a pair of finger parts 12. 3A, the end surface of the main body part 11 where the main body part 11 and the pair of finger parts 12 are joined, and an intermediate position between the positions where each of the finger parts 12 is joined to the main body part 11. Is the robot hand position 13.
3A shows a relative movement of the grip 10d toward the component 220b, FIG. 3B shows a pair of finger portions 12 arranged around the component 220b, and FIG. 3C shows a component 220b. When the component 220b is sandwiched between the pair of finger portions 12 from the side of FIG. 3, FIG. 3 (d) shows the gripping portion 10d gripping the component 220b.
In FIG. 3, reference numerals G1, G2, G3, and G4 are contact points between the pair of finger portions 12 and the component 220b.

  As shown in FIG. 3A, the arm portion 10b is controlled to move the grip portion 10d relative to the component 220b. Next, the gripping part 10d is controlled to cause the gripping part 10d to grip the component 220b. Here, the gripping part 10d is made to realize the three functions of caging, self-alignment, and frictional gripping of the component 220b.

  “Caging” means that the object (for example, the component 220b) is in a space closed by the surface on which the grip portion 10d and the component 220b are arranged when the object is in a certain position / posture. In the caging, the position / posture of the component 220b is not restricted and is free. “Self-alignment” means that the part 220b is placed in a predetermined position in the closed space by the shape of the gripping part 10d and the frictional force between the gripping part 10d and the part 220b when the part 220b is sandwiched by the gripping part 10d. To move to. “Friction grip” means that the part 220b is brought into contact with the gripping part 10d at three or more contact points to restrain the part 220b, and the part 220b is perpendicular to the surface on which the part 220b is disposed by frictional force. It means holding in a restricted direction.

  Specifically, as shown in FIG. 3B, after the pair of finger parts 12 are arranged around the part 220b, the gripping part 10d is controlled to place the pair of finger parts 12 on the part 220b. The pair of finger parts 12 are surrounded by the pair of finger parts 12 so as to surround the part 220b. Thereby, the gripping part 10d prevents the component 220b from jumping out of the area surrounded by the pair of finger parts 12 (caging).

  Next, as shown in FIG. 3C, the component 220b is sandwiched between the pair of fingers 12 from the side of the component 220b. Thereby, the component 220b moves according to a pair of finger | toe parts 12, and this adjusts a position. Such automatic determination of the position is called self-alignment.

  Then, as shown in FIG. 3D, the component 220b is gripped by the pair of finger portions 12 at three or more contact points (here, four contact points) G1, G2, G3, and G4. Thereby, the component 220b is restrained at a predetermined position. This is called frictional gripping.

FIG. 4 is a diagram schematically showing a process in which the component (spur gear) 220b is attached to the shaft 210b of the base 200 in the spur gear assembly in the embodiment.
In the figure, a component 220a has a marker 222a used for rough detection and a target used for fine detection. In the figure, the shaft hole 221a is the target. Similarly, the component 220b has a marker 222b used for coarse detection and a target used for fine detection. In the figure, the shaft hole 221b is the target.

The marker 222a or the marker 222b is, for example, a circumferential curve as shown in FIG. A shaft hole 221a as a target is placed inside the marker 222a. Moreover, the shaft hole 221b which is a target has entered inside the marker 222b.
However, the center point of the circle of the marker 222a does not necessarily coincide with the center point of the shaft hole 221a. Further, the center point of the circle of the marker 222b does not necessarily coincide with the center point of the shaft hole 221b.

Since the marker 222 a or the marker 222 b is a subject imaged by the imaging device 20, the marker 222 a or the marker 222 b is provided so as to be visually identifiable by the imaging device 20. For example, the marker 222a or the marker 222b is colored with a paint having a color different from the outer color of the component 220a or the component 220b. In addition, the marker 222a or the marker 222b may be a sticker instead of a paint application. Further, the marker 222a or the marker 222b may be obtained by processing the part 220a or 220b itself. For example, the marker 222a or the marker 222b may be obtained by cutting a circumferential curve on the surface of a spur gear. Further, when the material of the component 220a or 220b is metal, resin, or the like, the marker 222a or the marker 222b can be formed by press working or injection molding.
By making the marker 222a or the marker 222b a circumferential curve, it is possible to accurately identify the subject even when the subject rotates in the plane of the image.

  4A, 4B, and 4C, the component 220a or the component 220b is gripped by the grip portion 10d, but the grip portion 10d is not shown. As shown in FIG. 4A, first, the gripping part 10d conveys the component 220a to a position where the central axis of the shaft hole 221a coincides with the axis of the shaft 210a and is above the shaft 210a. The shaft 210a is passed through the shaft hole 221a and attached to the base 200 by being conveyed in the direction of arrow C, which is vertically downward.

  Subsequently, the grip portion 10d conveys the component 220b to a position where the central axis of the shaft hole 221b coincides with the shaft 210b and is above the shaft 210b. Then, the gripping unit 10d transports the component 220b in the direction of arrow D, which is next vertically downward. As a result, the grip portion 10d allows the shaft hole 221b to pass through the end surface 211b opposite to the surface joined to the base 200 of the shaft 210b, and the shaft 210b passes through the shaft hole 221b.

  FIG. 4B shows that the component 220b is located in a state where the shaft 210a passes through the shaft hole 221a and the component 220b does not contact the base 200 and the component 220a. With the component 220b positioned in that position, the gripping portion 10d moves to a predetermined rotation direction (in this example, left-handed when viewed from above) up to an angle at which the component 220b and the component 220a can be fitted together. ) To rotate the component 220b.

  The gripping portion 10d rotates the component 220b to an angle at which the component 220b can be fitted with the component 220a, and then conveys the component 220b vertically downward as shown in FIG. Attach to 200. As a result, the gripping portion 10d can install the component 220b and the component 220a on the base 200 so that the tooth tips of the component 220b and the component 220a mesh with each other.

  FIG. 5 is a schematic block diagram showing the configuration of the position detection device 30 according to the embodiment. As shown in the figure, the position detection device 30 includes an image data acquisition unit 31, a marker goal image storage unit 32, a marker detection unit 33, a marker position adjustment unit 35, a target goal image storage unit 36, and a target. A detection unit 37 and a target position adjustment unit 39 are provided.

  The image data acquisition unit 31 captures image data supplied from the imaging device 20 in units of frames, supplies the captured image data to the marker detection unit 33 in the coarse detection mode, and captures the captured image data in the fine detection mode. This is supplied to the target detection unit 37.

  The marker goal image storage unit 32 stores marker goal image data that is an image in a state where the marker is located at the marker goal position. For example, the marker goal image storage unit 32 stores marker goal image data in a state in which the marker 222 represented by a circumferential curve is provided at a position surrounding the target axis 210.

  In the coarse detection mode, the marker detection unit 33 captures the image data supplied from the image data acquisition unit 31 and reads the marker goal image data from the marker goal image storage unit 32. Then, the marker detection unit 33 executes marker detection processing by the template matching method using the marker goal image data, detects the marker from the image data, and the coordinate value (xt, yt) of the detected reference position of the marker To get. For example, in the marker 222 represented by a circumferential curve, the center position of the circumference is set as the reference position (xt, yt) of the marker 222. Note that the origin of the coordinate system in the image is, for example, the pixel position at the upper left corner of the image. Then, the marker detection unit 33 uses the coordinate value (xt, yt) of the marker reference position in the image data and the coordinate value (xg, yg) of the marker reference position in the marker goal image data as the marker position adjustment unit 35. To supply.

  For example, the marker detection unit 33 searches the image data for a place where the pattern matches while shifting a partial image (marker image) including the marker in the marker goal image data by one pixel or several pixels. When the marker detection unit 33 detects a place where the patterns match, the marker detection unit 33 acquires the coordinate value (xt, yt) of the reference position of the marker at the place, and the coordinate value (xt, yt) of the reference position of the marker ) And the coordinate value (xg, yg) of the reference position of the marker in the marker goal image data are supplied to the marker position adjustment unit 35.

  In the coarse detection mode, the marker position adjustment unit 35 is supplied from the marker detection unit 33, and the coordinate value (xt, yt) of the marker reference position in the image data and the coordinate value of the marker reference position in the marker goal image data ( xg, yg). The marker position adjustment unit 35 then calculates a difference value (xg−xt) between the coordinate value (xg, yt) of the marker reference position in the marker goal image data and the coordinate value (xt, yt) of the marker reference position in the image data. , Yg-yt) generates a robot control command that moves the marker in the direction of (0, 0) and supplies it to the robot controller 50.

  In addition, the marker position adjustment unit 35 takes in the robot control status supplied from the robot control device 50, and supplies the imaging request command to the imaging device 20 when the content of the robot control status indicates content indicating the success of control. To do.

  The target goal image storage unit 36 stores target goal image data that is an image in a state where the reference position of the target is located at the target goal position. For example, the target goal image storage unit 36 stores target goal image data in a state where the shaft hole 221 of the spur gear is provided at a position where the center of the shaft hole 221 of the spur gear coincides with the axis center of the shaft 210.

  The target detection unit 37 reads the image data supplied from the image data acquisition unit 31 and also reads the target goal image data from the target goal image storage unit 36 in the fine detection mode. Then, the target detection unit 37 executes target detection processing by the template matching method using the target goal image data in the image area of the marker, detects the target from the image data, and coordinates of the reference position of the detected target Get the value (xp, yp). For example, when the target is the shaft hole 221 of the component 220 (spur gear), the center position of the shaft hole 221 is set as the reference position (xp, yp). Then, the target detection unit 37 supplies the coordinate value (xt, yt) of the reference position in the image data and the coordinate value (xo, yo) of the target reference position in the target goal image data to the target position adjustment unit 39. To do.

  For example, the target detection unit 37 searches the image data for a place where the pattern matches while shifting a partial image (target image) including the target in the target goal image data pixel by pixel. Then, when the target detection unit 37 detects a place where the patterns match, the target detection unit 37 acquires the coordinate value (xp, yp) of the reference position of the target at the place, and the coordinate value (xp, yp) of the reference position of the target ) And the coordinate value (xo, yo) of the reference position of the target in the target goal image data are supplied to the target position adjustment unit 39.

  In the fine detection mode, the target position adjustment unit 39 supplies the coordinate value (xp, yp) of the target reference position in the image data and the coordinate value of the target reference position in the target goal image data (supplied from the target detection unit 37). xo, yo). Then, the target position adjustment unit 39 calculates a difference value (xo−xp) between the coordinate value (xo, yo) of the target reference position in the target goal image data and the coordinate value (xp, yp) of the target reference position in the image data. , Yo-yp) generates a robot control command that moves the target in the direction of (0, 0) and supplies it to the robot controller 50.

  Further, the target position adjustment unit 39 takes in the robot control status supplied from the robot control device 50, and supplies the imaging request command to the imaging device 20 when the content of the robot control status indicates the content of the control success. To do.

  FIG. 6 is a schematic block diagram showing the configuration of the robot control device 50 according to the embodiment. As shown in the figure, the robot control device 50 includes a storage unit 51, an input unit 52, a correspondence calculation unit 53, a correspondence acquisition unit 54, a coordinate conversion unit 55, and a robot hand position calculation unit 56. The post-rotation position calculation unit 57 and the movement control unit 58 are provided.

The storage unit 51 stores rotation angles φ1 to φ6 of each of the six axes of the robot body 10.
The storage unit 51 stores a correspondence relationship between a coordinate system in an image (hereinafter referred to as an image coordinate system) and a coordinate system of the robot body 10 (hereinafter referred to as a robot coordinate system). Specifically, the storage unit 51 stores in advance an equation for coordinate conversion from the image coordinate system to the robot coordinate system.
The correspondence relationship is, for example, a coordinate conversion formula, but may be a table in which the coordinates in the image coordinate system and the coordinates in the robot coordinate system are associated one-to-one.

Here, the coordinate conversion formula is calculated in advance by the following processing, for example.
For example, the robot apparatus 1 causes the imaging apparatus 20 to image the robot hand position while moving the robot hand position with a certain marker on a plane perpendicular to the optical axis of the imaging apparatus 20. The designer acquires the positions Pf of the plurality of markers in the captured image. The designer actually measures the marker position Pr in the robot coordinate system. Note that the positions Pf of the plurality of markers in the image captured by the robot control device 50 may be extracted.

Then, the input unit 52 accepts input of a plurality of marker positions Pf on the image and a plurality of marker positions Pr in the robot coordinate system corresponding to them, and inputs the received positions to the correspondence calculation unit 53. Output.
The correspondence calculation unit 53 calculates the above-described coordinate conversion formula based on the plurality of marker positions Pf on the received image and the corresponding plurality of marker positions Pr in the robot coordinate system. Specifically, for example, the correspondence calculation unit 53 uses the plurality of marker positions Pf and the corresponding plurality of marker positions Pr to calculate a coordinate conversion formula by camera calibration. Then, the correspondence calculation unit 53 causes the storage unit 51 to store the calculated coordinate conversion formula.

  The correspondence relationship acquisition unit 54 acquires the correspondence relationship between the image coordinate system and the robot coordinate system. Specifically, for example, the correspondence acquisition unit 54 reads the coordinate conversion formula, which is an example of the above-described correspondence relationship, from the storage unit 51 to acquire the coordinate conversion formula. Then, the correspondence relationship acquisition unit 54 outputs the acquired coordinate conversion formula to the coordinate conversion unit 55.

The coordinate conversion unit 55 converts the position specified in the image (for example, the center position of the image) into a position in the robot coordinate system based on the correspondence acquired by the correspondence acquisition unit 54. It should be noted that the center position of the image need not be exactly the center of the image, but may be near the center of the image and may be a position excluding the edge of the image.
Specifically, the coordinate conversion unit 55 performs coordinate conversion of a position designated in advance in the image into a position in the robot coordinate system in accordance with the coordinate conversion formula input from the correspondence acquisition unit 54.

For example, the coordinate conversion unit 55 holds the center position (u _c , v _c ) of the image in advance. Then, the coordinate conversion unit 55 coordinates the center position (u _c , v _c ) of the image to the center position (X _c , Y _c ) in the robot coordinate system according to the coordinate conversion formula input from the correspondence acquisition unit 54. Convert.
The coordinate conversion unit 55 receives the specified position information indicating the specified position in the robot coordinate system (for example, the center position (X _c , Y _c ) in the robot coordinate system) obtained by the conversion, and the post-rotation position calculation unit 57 and the movement control unit. Output to 58.

The robot hand position calculation unit 56 calculates the robot hand position based on the angles of the arms included in the robot body. Here, the arm includes the arm portion 10b and the hand portion 10c. Specifically, for example, the robot hand position calculation unit 56 calculates the robot hand position by the following process.
The robot hand position calculation unit 56 reads the rotation angles φ1 to φ6 of each of the six axes of the robot body 10 from the storage unit 51. Then, the robot hand position calculation unit 56 calculates the robot hand position (X ₁ , Y ₁ ) in the robot coordinate system using the read rotation angles φ1 to φ6 according to a known inverse kinematic process. The robot hand position calculation unit 56 outputs the robot hand position information indicating the calculated robot hand position (X ₁ , Y ₁ ) to the post-rotation position calculation unit 57.

The post-rotation position calculation unit 57 is based on the position in the robot coordinate system obtained by the coordinate conversion by the coordinate conversion unit 55 and the robot hand position indicating the position of the robot hand in the robot coordinate system. Calculate the robot hand position.
Specifically, the post-rotation position calculation unit 57 calculates the position indicated by the specified position information input from the coordinate conversion unit 55 (for example, the center position (X _c , Y _c ) in the robot coordinate system) and the robot hand position calculation. Using the position (X ₁ , Y ₁ ) indicated by the robot hand position information input from the unit 56, the robot hand position (X ₂ , Y ₂ ) after rotation is calculated according to the following equation (1).

Here, θ is a predetermined rotation angle. The post-rotation position calculation unit 57 outputs post-rotation robot hand position information indicating the post-rotation robot hand position (X ₂ , Y ₂ ) obtained by the calculation to the movement control unit 58.

  The movement control unit 58 moves the rotation center position of the object (for example, the component 220b) held by the robot body 10 to a designated position in the robot coordinate system obtained by the coordinate conversion unit 55 performing coordinate conversion. The robot body 10 is controlled. More specifically, the movement control unit 58 moves the rotation center position of the object held by the robot body 10 to the designated position indicated by the designated position information in the robot coordinate system input from the coordinate conversion unit 55. The main body 10 is controlled.

Further, the movement control unit 58 rotates the hand of the robot around the designated position in the robot coordinate system so that the hand of the robot moves to the position of the robot hand after rotation calculated by the position calculation unit 57 after rotation. Specifically, the movement control unit 58 in the robot coordinate system moves the robot hand position to the position (X ₂ , Y ₂ ) indicated by the post-rotation robot hand position information input from the post-rotation position calculation unit 57. The hand of the robot is rotated around a designated position in a predetermined rotation direction.

  Further, the movement control unit 58 controls the robot body 10 based on the robot control command input from the position detection device 30. Further, after controlling the robot body 10, the movement control unit 58 generates a robot control status including information indicating whether or not the control is successful, and supplies the generated robot control status to the position detection device 30. .

FIG. 7 is a diagram for explaining processing of the robot control device 50 in the embodiment. In the drawing, an example of a schematic diagram 71 of the first photographed image and an example of a schematic diagram 72 of the second photographed image after the grip portion 10d is moved are shown.
In the schematic diagram 71 of the first photographed image, the center position of the shaft hole 221b of the component 220b and the image center position (u _c , v _c ) are shown in the image coordinate system (UV coordinate system). Here, the following description will be made assuming that the image center position (u _c , v _c ) coincides with the center of the end face of the shaft 210b as an example.

When the grip portion 11d is moved, the robot apparatus 1 moves the grip portion 11d by performing the following processing.
First, the position detection device 30 detects the center position of the shaft hole 221b in the image coordinate system, and outputs shaft hole center position information indicating the detected center position of the shaft hole 221b to the coordinate conversion unit 55 of the robot control device 50. .

The coordinate conversion unit 55 converts the center position of the shaft hole 221b indicated by the shaft hole center position information input from the position detection device 30 into the center position of the shaft hole 221b in the robot coordinate system. In addition, the coordinate conversion unit 55 converts the previously held image center position into an image center position (X _c , Y _c ) in the robot coordinate system. The coordinate conversion unit 55 obtains the robot coordinate axis hole center position information indicating the center position of the shaft hole 221b in the robot coordinate system obtained by the conversion and the robot coordinate image center indicating the image center position (X _c , Y _c ) in the robot coordinate system. The position information is output to the movement control unit 58.

  The movement control unit 58 calculates the direction and distance to move the robot based on the robot coordinate axis hole center position information and the robot coordinate image center position information input from the coordinate conversion unit 55. Specifically, for example, the movement control unit 58 calculates the direction from the position indicated by the robot coordinate axis hole center position information to the position indicated by the robot coordinate image center position information as the direction of moving the robot. Further, for example, the movement control unit 58 calculates the distance between the position indicated by the robot coordinate axis hole center position information and the position indicated by the robot coordinate image center position information as the distance to move the robot.

Then, the movement control unit 58 instructs the robot to move by the calculated distance in the calculated direction. Thereby, the movement control part 58 can move the holding part 11d so that the center position of the shaft hole 221b in the robot coordinate system becomes the image center position (X _c , Y _c ) in the robot coordinate system.

Subsequently, a schematic diagram 72 of the second photographed image in the same figure is picked up after the gripping part 11d is moved so that the center position of the gripping object becomes the image center position (u _c , v _c ) in the image. FIG. In the schematic diagram 72 of the second photographed image in the same figure, it is shown that the center position of the grasped object is located at the image center position (u _c , v _c ). In the schematic diagram 72 of the second captured image in the same figure, the robot hand position (u ₁ , v ₁ ) in the image coordinate system is shown.

After acquiring the second captured image, the position detecting device 30 extracts the robot hand position (u _{1, v 1)} in the image coordinate system, the extracted robot hand position indicating the robot hand position (u _{1, v 1)} Information is output to the coordinate conversion unit 55 of the robot controller 50.
The coordinate conversion unit 55 converts the robot hand position (u ₁ , v ₁ ) indicated by the robot hand position information input from the position detection device 30 into the robot hand position (X ₁ , Y ₁ ) in the robot coordinate system. The coordinate conversion unit 55 outputs post-conversion robot hand position information indicating the robot hand position (X ₁ , Y ₁ ) obtained by the conversion to the movement control unit 58.

FIG. 8 is a diagram illustrating a relationship between the grip portion 10d before rotation and the grip portion 10d after rotation in the embodiment. In the figure, an example of a schematic diagram 81 of the gripping part 10d before rotation and a schematic diagram 82 of the gripping part 10d after rotation are shown. Also, the rotation center position (X _c , Y _c ) in the robot coordinate system, the robot hand position (X ₁ , Y ₁ ) before rotation in the robot coordinate system, and the robot hand position (X ₂ ) after rotation in the robot coordinate system. , Y ₂ ) is shown. The robot hand position (X ₂ , Y ₂ ) after rotation in the robot coordinate system is the robot when the gripping portion 81 rotates counterclockwise θ around the rotation center position (X _c , Y _c ) in the robot coordinate system. The hand position.

In the example of the figure, the post-rotation position calculation unit 57, for example, includes a rotation center position (X _c , Y _c ) in the robot coordinate system and a robot hand position (X ₁ , Y ₁ ) before rotation in the robot coordinate system. Then, a predetermined rotation angle θ is applied to the equation (1) to calculate the robot hand position (X ₂ , Y ₂ ) after rotation in the robot coordinate system. Then, the post-rotation position calculation unit 57 outputs post-rotation robot hand position information indicating the calculated post-rotation robot hand position (X ₂ , Y ₂ ) to the movement control unit 58.
Then, the movement control unit 58 controls the robot body 10 so as to move the robot hand position to the position (X ₂ , Y ₂ ) indicated by the post-rotation robot hand position information input from the post-rotation position calculation unit 57.

  FIG. 9 is a flowchart illustrating a first example of processing in which the robot apparatus 1 attaches the component 220b to the shaft 210b. Here, it is assumed that the component 210a is already attached to the shaft 210a, and the end surface 211b opposite to the surface joined to the base 200 of the shaft 210b is located at the center of the image.

First, the movement control unit 58 controls the robot body 10 to move the center position of the shaft hole 221b of the component 220b to the center position of the image in the space above the end surface 211b (step S101). Next, the movement control unit 58 controls the robot body 10 so as to fit the component 220b into the shaft 210b (step S102). Next, the coordinate conversion unit 55 converts the rotation center position in the image coordinate system to the rotation center position (X _c , Y _c ) in the robot coordinate system (step S103).

  Next, the robot hand position calculation unit 56 calculates the robot hand position in the robot coordinate system based on the rotation angles φ1 to φ6 of the six axes of the robot body 10 (step S104). Next, the post-rotation position calculation unit 57 calculates the post-rotation robot hand position from the rotation center position in the robot coordinate system and the robot hand position in the robot coordinate system (step S105). Next, the movement control unit 58 controls the robot body 10 to rotate the robot hand position to the robot hand position after the rotation (step S106).

  Next, the robot control device 50 causes the imaging device 20 to take an image so that the component 220a and the component 220b are in the field of view (step S107). Next, the movement control unit 58 determines whether or not the tooth tip of the component 200a overlaps the tooth tip of the component 200b in the image captured in step S107 (step S108). If the tooth tip of the component 200a and the tooth tip of the component 200b overlap (YES in step S108), the robot control device 50 returns to the process of step S104. On the other hand, if the tooth tip of the component 200a and the tooth tip of the component 200b do not overlap (NO in step S108), the movement control unit 58 controls the robot body 10 to fit the component 220b into the component 220a (step S109). Above, the process of this flowchart is complete | finished.

  The robot control device 50 moves the rotation center position (the center position of the shaft hole 221b) of the object (for example, the component 220b) held by the robot body 10 to the center position of the image captured by the imaging device 20. The robot body 10 is controlled. As a result, even if the rotation center position of the object changes each time the object is gripped, the robot control apparatus 50 moves the rotation center position of the object to the center position of the image and uses the center position of the image as an axis to move the object. Can be rotated. As a result, the robot control device 50 does not need to measure the rotation center position of the object being gripped, so that it is possible to reduce the trouble of rotating the component.

  Further, the robot control device 50 moves the center position (or center of gravity position) of the shaft hole 221b of the component 220b to the center position of the image. As a result, the center position of the image has little distortion of the optical system, and the center position of the image accurately indicates the position of the subject. Therefore, the robot controller 50 can also accurately move the part 220b in the sub-pixel order. Can be moved. That is, the robot controller 50 can align the position of the component 220b with high accuracy by a simple method.

  In addition, since the robot control device 50 accurately indicates the position of the subject, the center position of the image does not need to be calibrated such as correcting optical distortion of the imaging device 20, and thus it takes time and effort for calibration. And can save time.

  Since the robot apparatus 1 controls the component 220b to be at the center position of the image, the component 220b is positioned in the vicinity of the center of the image even when the imaging device 20 zooms. As a result, the robot apparatus 1 needs to move the component 220b so that it enters the imaging range after zooming when the component 220b is moved to the center position of the image and then zoomed to adjust the position of the component 220b at the pixel level. Therefore, it is possible to reduce the labor and time required for position adjustment after zooming.

In the image captured by the imaging device 200, the robot control device 50, when the end surface image area indicating the end surface 211b opposite to the surface joined to the base 200 of the shaft 210b is not located at the center position of the image, The center of gravity of the end face image area may be extracted, and the component 220b may be moved to the center of gravity of the end face image area. Here, the center of gravity of the end face image area may be the center of the end face image area.
Thereby, even if the accuracy of positioning of the shaft 210b by the conveyor 100 is low, the robot controller 50 can rotate the component 220b with the center of gravity or the center of the end face image area as the rotation center.

  FIG. 10 is a flowchart showing an example of details of the processing in step S101 in FIG. In the assembly production line of the factory shown in FIG. 2, the shaft 210b of the assembly part to be assembled among the plurality of assembly parts arranged on the movable mounting table by the conveyor 100 is substantially directly below the imaging apparatus 20, that is, the imaging apparatus. After the operation of the movable mounting table is stopped at a position where the optical axis of the 20 lens optical system and the axis 210b substantially coincide with each other and the position detection device 30 is set to the coarse detection mode, the processing of the flowchart of FIG. 10 is executed. The

  First, in step S <b> 201, the imaging device 20 images an assembly component that is an assembly target, and supplies image data obtained by the imaging to the position detection device 30.

  Next, in step S202, the position detection device 30 takes in the image data supplied from the imaging device 20, and uses the search region as an entire image, for example, to search for a marker provided on the component 220b from the image. To detect.

  The process of step S202 will be described in detail. The image data acquisition unit 31 of the position detection device 30 takes in the image data supplied from the imaging device 20 and supplies it to the marker detection unit 33. Next, the marker detection unit 33 takes in the image data supplied from the image data acquisition unit 31 and reads the marker goal image data from the marker goal image storage unit 32. Next, the marker detection unit 33 performs marker search processing by the template matching method using the marker goal image data, detects the marker from the image data, and coordinates (xt, yt) of the detected reference position of the marker ) To get. Next, the marker detection unit 33 uses the marker reference position coordinate value (xt, yt) in the image data and the marker reference position coordinate value (xg, yg) in the marker goal image data as a marker position adjustment unit. 35.

  Next, in step S203, the marker position adjustment unit 35 is supplied from the marker detection unit 33, and the coordinate value (xt, yt) of the marker reference position in the image data and the coordinate of the marker reference position in the marker goal image data. Take in the value (xg, yg). Next, the marker position adjustment unit 35 calculates a difference value (xg−) between the coordinate value (xg, yt) of the marker reference position in the marker goal image data and the coordinate value (xt, yt) of the marker reference position in the image data. xt, yg-yt) is calculated. Next, if the difference value is not (0, 0), the marker position adjustment unit 35 determines that the marker is not goal and moves to the process of step S4.

  In step S <b> 204, the marker position adjustment unit 35 generates a robot control command for moving the marker in the direction in which the difference value is (0, 0), and supplies the robot control command to the robot control device 50. Next, the robot control device 50 takes in the robot control command supplied from the position detection device 30, and based on the robot control command, any of the arm unit 10b, the hand unit 10c, and the gripping unit 10d of the robot body 10 is selected. Control the operation of one or a combination. The robot body 10 moves one or a combination of the arm unit 10b, the hand unit 10c, and the gripping unit 10d under the control of the robot control device 50. Next, after controlling the robot body 10, the robot control device 50 supplies the position detection device 30 with a robot control status including information indicating whether or not the control is successful.

  Next, in step S205, the marker position adjustment unit 35 of the position detection device 30 takes in the robot control status supplied from the robot control device 50, and when the content of this robot control status is the content indicating the success of the control. Then, the imaging request command is supplied to the imaging apparatus 20, and the process returns to step S1.

  On the other hand, if the marker position adjustment unit 35 determines that the difference value is (0, 0) in the process of step S203, the position detection device 30 is set to the fine detection mode, and the process proceeds to step S206.

  In step S <b> 206, the imaging device 20 images an assembly part that is an assembly target, and supplies image data obtained by the imaging to the position detection device 30.

  In step S207, the position detection device 30 takes in the image data supplied from the imaging device 20, and performs a template matching process on the image in which the search region is limited to the marker region, and the target (flat) of the component 220b from the limited region of the image. Detect the gear shaft hole).

  The process of step S207 will be described in detail. The image data acquisition unit 31 of the position detection device 30 captures the image data supplied from the imaging device 20 in units of frames and supplies it to the target detection unit 37. Next, the target detection unit 37 takes in the image data supplied from the image data acquisition unit 31 and reads the target goal image data from the target goal image storage unit 36. Next, the target detection unit 37 executes target search processing by the template matching method using the target goal image data in the image area of the marker, detects the target from the image data, and detects the reference position of the detected target. A coordinate value (xp, yp) is acquired. Next, the target detection unit 37 sends the coordinate value (xt, yt) of the reference position in the image data and the coordinate value (xo, yo) of the target reference position in the target goal image data to the target position adjustment unit 39. Supply.

  Next, in step S208, the target position adjustment unit 39 supplies the coordinate value (xp, yp) of the target reference position in the image data and the coordinates of the target reference position in the target goal image data supplied from the target detection unit 37. The value (xo, yo) is taken in. Next, the target position adjustment unit 39 calculates the difference value (xo−) between the coordinate value (xo, yo) of the target reference position in the target goal image data and the coordinate value (xp, yp) of the target reference position in the image data. xp, yo-yp). Next, when the difference value is not (0, 0), the target position adjustment unit 39 determines that the target is not goal and moves to the process of step S209.

  In step S <b> 209, the target position adjustment unit 39 generates a robot control command that moves the target in the direction in which the difference value is (0, 0), and supplies the generated robot control command to the robot control device 50. Next, the robot control device 50 takes in the robot control command supplied from the position detection device 30, and based on the robot control command, any of the arm unit 10b, the hand unit 10c, and the gripping unit 10d of the robot body 10 is selected. Control the operation of one or a combination. The robot body 10 moves one or a combination of the arm unit 10b, the hand unit 10c, and the gripping unit 10d under the control of the robot control device 50. Next, after controlling the robot body 10, the robot control device 50 supplies the position detection device 30 with a robot control status including information indicating whether or not the control is successful.

  Next, in step S210, the target position adjustment unit 39 of the position detection device 30 takes in the robot control status supplied from the robot control device 50, and when the content of this robot control status is the content indicating the success of the control. Then, the imaging request command is supplied to the imaging apparatus 20 and the process returns to step S206.

  On the other hand, when the target position adjustment unit 39 determines that the difference value is (0, 0) in the process of step S208, the process of this flowchart ends.

  FIG. 11 is a flowchart showing a second example of the process in which the robot apparatus 1 attaches the component 220b to the shaft 210b. 9 is different from the process of the flowchart of FIG. 9 in that the center position of the shaft hole 221b of the component 220b is moved to a predetermined position in the image instead of the center position of the image. Here, the component 220a is already attached to the shaft 210a, and the end surface 211b opposite to the surface joined to the base 200 of the shaft 210b is located at a predetermined position in the image. Assuming

  First, the movement control unit 58 controls the robot body 10 to move the center position of the shaft hole 221b to a predetermined position in the image (step S301). Next, the movement control unit 58 controls the robot body 10 so as to fit the component 220b into the shaft 210b (step S302).

  Next, the movement control unit 58 performs coordinate conversion from a predetermined position in the image in the image coordinate system to a position in the robot coordinate system (step S303). Next, the robot hand position calculation unit 56 calculates the robot hand position in the robot coordinate system based on the rotation angles φ1 to φ6 of the six axes of the robot body 10 (step S304). Next, the post-rotation position calculation unit 57 calculates the post-rotation robot hand position from the rotation center position in the robot coordinate system and the robot hand position in the robot coordinate system (step S305).

  Next, the movement control unit 58 rotates the robot hand position to the rotated robot hand position (step S306). Next, the robot control device 50 causes the imaging device 20 to take an image so that the component 220a and the component 220b are in the field of view (step S307). Next, the movement control unit 58 determines whether or not the tooth tip of the component 200a overlaps the tooth tip of the component 200b in the image captured in step S307 (step S308). If the tooth tip of the component 200a and the tooth tip of the component 200b overlap (YES in step S308), the robot control device 50 returns to the process of step S304. On the other hand, when the tooth tip of the component 200a and the tooth tip of the component 200b do not overlap (NO in step S308), the movement control unit 58 controls the robot body 10 to fit the component 220b into the component 220a (step S109). Above, the process of this flowchart is complete | finished.

  As described above, the robot control device 50 according to the present embodiment moves the center position of the shaft hole 221b of the component 220b to a predetermined position in the image. Then, the robot control device 50 rotates the component 220b around the predetermined position in the image. In other words, the robot control device 50 can rotate the component 220b around a predetermined position in the image as well as the center position of the image.

  As a result, the robot control device 50 can rotate the component 220b if the shaft 210b is positioned within the imaging range of the imaging device 20 without the shaft 210b being positioned at the center position of the image in advance. it can. For example, if it is difficult to fit the component 220b when the shaft 210b is positioned at the center of the image, even if the position of the shaft 210b is not a center position of the image but a predetermined position of the image, the robot control device 50 The component 220b can be rotated around the position of the shaft 210b. Thereby, the robot control apparatus 50 can improve processing efficiency. Thus, the robot control device 50 can freely set the position of the shaft 210b, that is, the rotation center position within the imaging range of the imaging device 20, so that the degree of freedom in assembly can be improved.

Note that the robot control device 50 changes the position where the component 220b is rotated in accordance with information on the size related to the component 220b extracted from the image captured by the imaging device 20 (for example, the size of the shaft hole 221b). Also good.
Specifically, for example, when the diameter of the shaft hole 221b is shorter than a predetermined length, the robot control device 50 rotates the component 220b at the center position of the image, and the diameter of the shaft hole 221b is a predetermined length. In such a case, the component 220b may be rotated at a predetermined position in the image.

  Thereby, the robot controller 50 gives priority to the accuracy of the position adjustment in the case of the component 220b that requires a high accuracy for the adjustment of the position of the component 220b, and requires the accuracy of the adjustment of the position of the component 220b. In the case of the part 220b which is not performed, priority can be given to processing efficiency or freedom of assembly.

  FIG. 12 is a schematic view of the gripping part 10d gripping and rotating other components and assembling them. This figure is a diagram in which the component 220d is transported in the vertically downward direction E so that the component 220d held by the pair of finger portions 12 passes through the shaft 210d joined to the base 200. Also, in the same figure, the component 220c is already attached to the base 200 in a state where the shaft 210c joined to the base 200 is passed.

As shown in the figure, the gripping part 10d needs to have a substantially circular target part. However, if the part has a two-stage structure as shown in the figure, the shape of the first stage which is the target part is shown. Is substantially circular, the shape of the second stage that is not the gripped portion may not be substantially circular. Here, “substantially circular” includes a shape having irregularities on the side periphery such as an ellipse or a gear.
Even when there is a part that needs to be aligned with a part to be assembled in a part of the second stage as shown in the same figure, it is necessary to rotate the part through the shaft. The present invention is also applicable to assembly of such parts.

<Effect>
As described above, the robot control device 50 according to the present embodiment has the rotation center position (shaft hole 221b) of the object (for example, the component 220b) held by the robot body 10 at a position specified in advance in the image captured by the imaging device 20. The robot main body 10 is controlled so as to move the center position). Thereby, even if the rotation center position of the object changes every time the object is gripped, the robot control device 50 moves the rotation center position of the object to a specified position in the image, thereby The object can be rotated about the center position of the image. As a result, the robot control device 50 does not need to measure the rotation center position of the object being gripped, so that it is possible to reduce the trouble of rotating the component.

Further, since the robot control device 50 rotates the robot hand around the designated position in the robot coordinate system, even if the distance between the rotation center position of the object and the robot hand position changes every time the object is gripped, the object Can be rotated with the rotation center position as an axis.
Since the robot controller 50 rotates the component 200b to a position where the tooth tip of the component 200a and the tooth tip of the component 200b do not overlap in the image captured by the imaging device 10, the component 220a and the component 220b are moved. Can be fitted together.

In addition, the grip portion 10d in this embodiment is effective only for a part having a specific shape, but the robot controller 50 is also applicable to parts having various shapes in which the self-alignment function is not effective. It can be rotated around the center of rotation accurately.
In addition, in this embodiment, although the grip part 10d which has a self-alignment function was demonstrated, it is not restricted to this, The grip part 10d does not need to have a self-alignment function.

When there are a plurality of types of parts to be gripped, conventionally, the type of the part gripped by the robot body 10 is specified by the person, the rotation center position in the part model measured in advance is selected, and the part is Since it is rotated, there is a problem that it takes a lot of time for processing.
According to this embodiment, the robot control device 50 can calculate the robot hand position after rotation in the robot coordinate system without having to measure the rotation center position in the part model in advance. Can be reduced.

Further, conventionally, when there are a plurality of types of parts to be gripped, it is not known which type of parts are held just by gripping the parts by the robot body 10, so the center position of the parts is not known, and as a result, which position There was a problem of not knowing whether to fit the axis.
According to the present embodiment, the robot control device 50 can specify the center position of the component in the image even if the gripped component is changed by the imaging device 20 imaging the component. Thereby, the robot control apparatus 50 can control to move the center position of the component to a predetermined position in the image (for example, the center position of the image). As a result, the robot controller 50 can match the center position of the component with the position of the axis.

In the present embodiment, as an example, the pair of finger portions 12 are described as being located on the same surface as the main body portion 11, but the pair of finger portions 12 are not on the same surface as the main body portion 11. It may be positioned at an angle in a direction away from the surface.
In that case, conventionally, the center position of the shaft hole 221b of the component 220b could not be calculated with high accuracy. On the other hand, since the robot control device 50 according to the present embodiment calculates the center position of the shaft hole 221b of the component 220b from the image captured by the imaging device 20, the center position of the shaft hole 221b of the component 220b can be accurately calculated. it can.

  Conventionally, there is a backlash of the robot body 10 itself, and there is a problem that the center position of the shaft hole 221b cannot always be moved to a predetermined position in the image (for example, the center position of the image). On the other hand, the robot control device 50 according to the present embodiment calculates the center position of the shaft hole 221b of the component 220b from the image captured by the imaging device 20, so that even if the robot main body 10 itself has a backlash, it is designated in advance in the image. It is possible to move to the designated position with high accuracy.

  In this embodiment, the number of the robot main body 10 is one, and the robot main body 10 rotates the component 220b while holding the component 220b. However, the present invention is not limited to this. There are two robot main bodies 10, one robot main body 10 rotates while grasping the part 220a, and the other robot main body 10 rotates while grasping the part 220b, and the parts 220a and 220b are fitted together. Also good.

FIG. 13 is a schematic external view of the robot apparatus according to the second embodiment.
In the figure, the robot apparatus 2 includes a robot body 60, a photographing apparatus 61, a gripping part 62, a robot control apparatus 50, and a cable 63.
The robot body 60, the robot control device 50, and the cable 63 are included in the robot device.
Since the robot control device 50 has the same configuration as that of the present embodiment, a detailed description of the robot control device 50 is omitted.

  Specifically, the robot main body 60 includes a main body 60a that is movably installed on the ground, a neck portion 60b that is pivotably coupled to the main body 60a, a head portion 60c that is fixed to the neck portion 60b, The first arm part 60d connected to the head part 60c so as to be able to bend and extend, the second arm part 60e connected to the head part 60c so as to be able to turn and bend and extend, and the robot body with respect to the installation surface of the robot body 60 60 includes a transfer section 60f attached to the main body 60a so as to be movable.

A grip part 62 is attached to the hand that is the open end of the first arm part 60d. A photographing device 61 is attached to the hand that is the open end of the second arm portion 60e.
The conveyance unit 60f supports the robot body 60 so that the robot body 60 can move in a certain direction or in a freely movable direction with respect to the installation surface of the robot body 60. The conveyance unit 60f is realized by four sets of wheels, four sets of casters, a pair of endless tracks, and the like.

  The robot body 60 is, for example, a vertical articulated robot (double arm robot) having two arms. The robot body 60 takes in the robot control command supplied from the robot control device 50, and changes the position and orientation of each of the imaging device 61 and the gripper 62 in the three-dimensional space as desired by drive control based on the robot control command. Further, the claw portion of the grip portion 62 is opened and closed.

The imaging device 61 captures a subject to acquire a captured image that is a still image or a moving image, and supplies the captured image to the robot control device 20. The photographing device 61 is realized by, for example, a digital camera device or a digital video camera device.
The holding part 62 includes a claw part that can hold an object. In FIG. 13, the gripping portion 62 is schematically shown in order to show its function.

  The cable 63 supplies a robot control command output from the robot control apparatus 20 to the robot main body 60, and supplies a robot control response output from the robot main body 60 to the robot control apparatus 20. The robot control command is a control command for driving and controlling each movable part of the robot body 60. The robot control response includes, for example, a response to a robot control command that the robot body 60 notifies the robot control device 20. The cable 63 is, for example, a cable such as a serial communication line or a computer network.

The robot control device 50 controls the operations of the neck 60b, the head 60c, and the second arm 60e of the robot body 60, and changes the position and posture of the photographing device 61. Specifically, the robot control device 50 installs the photographing device 61 at a position where the photographing direction is substantially vertically downward, substantially vertically above an assembly part (not shown).
Further, the robot control device 50 takes in a photographed image of the assembly part supplied from the photographing device 61, and based on the photographed image, the neck 60b, the head 60c, and the first arm of the robot main body 60. The operation with the part 60d is controlled, and the gear is passed through the shaft and attached to the assembly part as in the first embodiment.

As described above, the robot apparatus 2 according to the second embodiment includes the same robot control device 50 as the robot apparatus 1 according to the first embodiment, and has the same effects as those of the first embodiment.
The robot control device 50 may be housed in a cabinet of the main body 60a of the robot main body 60, for example.

  In addition, a program for executing each process of the position detection device 30 and the robot control device 50 of the present embodiment is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into a computer system. By executing, the above-described various processes relating to the position detection device 30 and the robot control device 50 may be performed.

  Here, the “computer system” may include an OS and hardware such as peripheral devices. Further, the “computer system” includes a homepage providing environment (or display environment) if a WWW system is used. The “computer-readable recording medium” means a flexible disk, a magneto-optical disk, a ROM, a writable nonvolatile memory such as a flash memory, a portable medium such as a CD-ROM, a hard disk built in a computer system, etc. This is a storage device.

  Further, the “computer-readable recording medium” refers to a volatile memory (for example, DRAM (Dynamic) in a computer system serving as a server or a client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. Random Access Memory)) that holds a program for a certain period of time is also included. The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, what is called a difference file (difference program) may be sufficient.

  As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, the concrete structure is not restricted to this embodiment, The design etc. of the range which does not deviate from the summary of this invention are included.

DESCRIPTION OF SYMBOLS 1, 2 Robot apparatus 10 Robot main body 10a Support stand 10b Arm part 10c Hand part 10d Gripping part 20 Imaging device (imaging part)
DESCRIPTION OF SYMBOLS 30 Position detection apparatus 31 Image data acquisition part 32 Marker goal image storage part 33 Marker detection part 35 Marker position adjustment part 36 Target goal image storage part 37 Target detection part 39 Target position adjustment part 50 Robot control apparatus (robot control part)
51 Storage Unit 52 Input Unit 53 Correspondence Relationship Calculation Unit 54 Correspondence Relationship Acquisition Unit 55 Coordinate Conversion Unit 56 Robot Hand Position Calculation Unit 57 Post-Rotation Position Calculation Unit 58 Movement Control Unit 60 Robot Main Body 60a Main Body 60b Neck 60c Head 60d First Arm Part 60e second arm part 60f conveying part 61 photographing apparatus 62 gripping part 63 cable

Claims (7)

A robot body that grips an object and transports it to a goal position;
An imaging unit that captures an image including the goal position and the object held by the robot body in a visual field;
A correspondence acquisition unit that acquires a correspondence between a coordinate system of an image captured by the imaging unit and a coordinate system of the robot body;
A coordinate conversion unit that converts the designated position in the image captured by the imaging unit to a designated position in the robot coordinate system based on the correspondence acquired by the correspondence acquisition unit;
Controlling the robot body to move the rotation center position of the object held by the robot body to a specified position in the robot coordinate system obtained by the coordinate conversion by the coordinate conversion unit; A movement control unit that rotates the object around a position;
A robot apparatus comprising:   The robot apparatus according to claim 1, wherein the designated position in the image is a center of the image. Based on the rotation center position in the robot coordinate system obtained by the coordinate conversion by the coordinate conversion unit and the robot hand position indicating the position held by the robot body in the robot coordinate system, the robot after rotation A post-rotation position calculation unit for calculating the hand position,
The movement control unit rotates the hand of the robot around a designated position in the robot coordinate system so that the hand of the robot moves to the position of the robot hand after rotation calculated by the position calculation unit after rotation. The robot apparatus according to claim 1, wherein the robot apparatus is characterized.   The robot apparatus according to claim 3, further comprising: a robot hand position calculation unit that calculates the robot hand position in the robot coordinate system based on angles of the joints of the arms included in the robot body. A robot control device that controls a robot body that grips an object and conveys it to a goal position,
A correspondence acquisition unit that acquires a correspondence between a coordinate system of an image captured by the imaging unit and a coordinate system of the robot body;
A coordinate conversion unit that converts the designated position in the image captured by the imaging unit to a designated position in the robot coordinate system based on the correspondence acquired by the correspondence acquisition unit;
The robot body is controlled to move the rotation center position of the object held by the robot body to a specified position in the robot coordinate system obtained by the coordinate conversion by the coordinate conversion unit, and the rotation center position A movement control unit for rotating the object around
A robot control device comprising: A robot control method executed by a robot control device that controls a robot body that grips an object and conveys it to a goal position,
A correspondence acquisition procedure for acquiring a correspondence between the coordinate system of the image captured by the imaging device and the coordinate system of the robot body;
A coordinate conversion procedure for converting the designated position in the image captured by the imaging device into a designated position in the robot coordinate system based on the correspondence acquired by the correspondence acquisition procedure;
Controlling the robot body to move the rotation center position of the object held by the robot body to a specified position in the robot coordinate system obtained by coordinate transformation by the coordinate transformation procedure; A movement control procedure for rotating the object around a position;
A robot control method comprising: To the computer of the robot controller that controls the robot body that grips the object and transports it to the goal position,
A correspondence acquisition step for acquiring a correspondence between a coordinate system of an image captured by the imaging device and a coordinate system of the robot body;
A coordinate conversion step of converting the designated position in the image captured by the imaging device into a designated position in the robot coordinate system based on the correspondence acquired by the correspondence acquisition step;
Controlling the robot body to move the rotation center position of the object held by the robot body to the designated position in the robot coordinate system obtained by the coordinate transformation in the coordinate transformation step; A movement control step of rotating the object around a position;
Robot control program to execute.

Images