JP2019115950A - Robot control device, robot, and robot system - Google Patents

Abstract

To provide a robot control device capable of accurately controlling a robot, and the robot and a robot system.SOLUTION: A robot control device controlling a robot, comprises: an image reception part receiving an image obtained by imaging an object; an angle calculation part calculating an angle between a first straight line included in the image and a second straight line along a coordinate axis in a coordinate system in the image; and a mode reception part receiving selection of a predetermined mode out of a plurality of modes. The plurality of modes includes a first mode which calculates a first angle between a third straight line having a predetermined angle with the second straight line and the first straight line, and causes the angle calculation part to calculate the angle such that the angle between the first straight line and the second straight line where an absolute value of the first angle is minimum becomes a detection angle of the first straight line.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a robot control device, a robot and a robot system.

  A robot is known that includes a base and a robot arm having a plurality of arms (links). One of two adjacent arms of the robot arm is pivotally connected to the other arm via the joint, and the most proximal (uppermost) arm is via the joint Is rotatably connected to the base. The joint is driven by a motor, and driving of the joint rotates the arm. Also, a hand is detachably mounted, for example, as an end effector on the most distal end (most downstream) arm. Then, for example, the robot holds an object with a hand, moves the object to a predetermined location, and performs predetermined operations such as assembly. In addition, the operation (drive) of such a robot is controlled by a robot control device.

  In addition, the imaging unit may perform imaging and operate the robot based on the obtained image to create an operation program of the robot. When the robot performs work, the imaging unit performs imaging, and the robot control device controls the robot based on the obtained image. In this case, for example, an angle between a straight line which is an edge of an object in an image and a straight line in a coordinate system in a coordinate system in the image is detected, and the robot is operated according to the angle.

  Further, Patent Document 1 discloses an image processing apparatus. In this image processing apparatus, the angle of the edge of the object in the image is obtained in the range of 0 ° to 360 °. Also, with respect to two edges extending in the same direction, the case in which the directions are different and the case in which the directions are the same is distinguished, and in the case where the directions are different, the angles of the two edges are different by 180 °.

JP, 2010-97438, A

  Here, with respect to two edges extending in the same direction of the object in the image, the case where the direction is different and the case where the direction is the same are easily confused. For this reason, there is a possibility that the worker may grasp the angle between the straight line detected by the image processing device described in Patent Document 1 and the straight line serving as the reference of the image coordinate system as an angle different by 180 °. When the end of the robot arm is rotated based on the above, there is a possibility that the end of the robot arm may be rotated by a large angle of 180 °. This may damage the cable provided on the robot arm.

  The present invention has been made to solve at least a part of the above-described problems, and can be realized as the following modes or application examples.

The robot control device of the present invention is a robot control device that controls a robot, and
An image reception unit that receives an image obtained by imaging an object;
An angle calculation unit that calculates an angle between a first straight line included in the image and a second straight line along a coordinate axis in a coordinate system of the image;
A mode reception unit that receives selection of a predetermined mode among a plurality of modes;
Equipped with
The plurality of modes calculate a first angle between a third straight line having a predetermined angle with the second straight line and the first straight line, and the absolute value of the first angle is most It is characterized in that it includes a first mode in which the angle calculation unit calculates the angle between the small first straight line and the second straight line to be the detected angle of the first straight line.

  According to such a robot control device, it is possible to control the robot appropriately. As a result, it is possible to prevent the tip of the robot arm of the robot from rotating at a large angle and damaging the cable provided on the robot arm.

  In the robot control device according to the present invention, the plurality of modes are within a predetermined range if a correction angle obtained by subtracting or adding 180 ° to an angle between the first straight line and the second straight line is within a predetermined range. It is preferable to include a second mode in which the correction angle is the detection angle.

  Thereby, in the second mode, the angle between the first straight line and the second straight line is calculated without distinguishing the case where the direction of the first straight line is reverse to the predetermined direction. Therefore, it is possible to prevent the tip of the robot arm of the robot from rotating at a large angle and damaging the cable provided on the robot arm.

  In the robot control device according to the present invention, it is preferable that the predetermined range is 0 ° or more and less than 180 °, or -90 ° or more and less than 90 °.

  Thereby, in the second mode, the angle between the first straight line and the second straight line is calculated without distinguishing the case where the direction of the first straight line is reverse to the predetermined direction. Therefore, it is possible to prevent the tip of the robot arm of the robot from rotating at a large angle and damaging the cable provided on the robot arm.

  In the robot control device according to the present invention, in the first mode, the angle calculation unit is configured to calculate the absolute value of the first angle when the absolute value of the first angle is within a predetermined range. Preferably, an angle between a straight line of 1 and the second straight line is used as the detection angle.

  Thereby, the first straight line and the second straight line having the smallest absolute value of the first angle between the third straight line having a predetermined angle with the second straight line and the first straight line The angle between the straight line and the straight line can be easily and quickly determined.

  In the robot control device according to the present invention, in the first mode, the angle calculation unit is configured to calculate the absolute value of the first angle when the absolute value of the first angle is not within a predetermined range. It is preferable that the correction angle obtained by subtracting or adding 360 ° to the angle between the straight line 1 and the second straight line is used as the detection angle.

  Thereby, the first straight line and the second straight line having the smallest absolute value of the first angle between the third straight line having a predetermined angle with the second straight line and the first straight line The angle between the straight line and the straight line can be easily and quickly determined.

The robot of the present invention has a robot arm,
It is controlled by the robot control device according to any one of claims 1 to 5.

  According to such a robot, an appropriate operation can be performed by control of the robot control device.

A robot system according to the present invention is a robot having a robot arm,
An imaging unit for imaging an object;
The robot control device according to any one of claims 1 to 5, which controls the robot.

  According to such a robot system, it is possible to control the robot appropriately. As a result, it is possible to prevent the tip of the robot arm of the robot from rotating at a large angle and damaging the cable provided on the robot arm.

1 shows an embodiment of a robot system of the present invention. It is a block diagram of a robot system shown in FIG. It is a top view for demonstrating the operation | work of the robot system shown in FIG. It is a figure which shows one example of the screen displayed on the display apparatus of the robot system shown in FIG. It is a figure for demonstrating the straight line detection of the robot system shown in FIG. It is a figure which shows the example of the property of the straight line detection of a robot system shown in FIG. It is a figure for demonstrating the straight line detection of the robot system shown in FIG. It is a figure for demonstrating the straight line detection of the robot system shown in FIG. It is a figure for demonstrating the straight line detection of the robot system shown in FIG. It is a figure for demonstrating the straight line detection of the robot system shown in FIG. It is a figure for demonstrating the straight line detection of the robot system shown in FIG. It is a figure for demonstrating the straight line detection of the robot system shown in FIG. It is a figure for demonstrating the straight line detection of the robot system shown in FIG. It is a block diagram for describing an embodiment centering on hardware (processor). It is a block diagram showing other example 1 (modification 1) of the robot system of the present invention. It is a block diagram showing other example 2 (modification 2) of a robot system of the present invention.

  Hereinafter, a robot control device, a robot and a robot system according to the present invention will be described in detail based on embodiments shown in the attached drawings.

Embodiment
«Robot system»
FIG. 1 is a view showing an embodiment of a robot system of the present invention. FIG. 2 is a block diagram of the robot system shown in FIG. FIG. 3 is a plan view for explaining the operation of the robot system shown in FIG. FIG. 4 is a view showing an example of a screen displayed on the display device of the robot system shown in FIG. FIG. 5 is a diagram for explaining straight line detection of the robot system shown in FIG. FIG. 6 is a diagram showing a specific example of straight line detection properties of the robot system shown in FIG. 7 to 13 are diagrams for explaining the straight line detection of the robot system shown in FIG. 1, respectively. FIG. 14 is a block diagram for describing the embodiment centering on hardware (processor). FIG. 15 is a block diagram showing another example 1 (modified example 1) of the robot system of the present invention. FIG. 16 is a block diagram showing another example 2 (modified example 2) of the robot system of the present invention.

  Further, in FIG. 1, xr axis, yr axis and zr axis are illustrated as three axes orthogonal to each other, and “+ (positive)” of the tip end of the arrow indicating each axis is “− (Negative) Further, the zr axis direction in FIG. 1 is referred to as “vertical direction”, and the direction along the xr-yr plane is referred to as “horizontal direction”. Also, the + zr axis side is referred to as “upper”, and the −zr axis side is referred to as “lower”. Also, the direction of the xr axis is referred to as "xr direction", the direction of the yr axis as "yr direction", and the direction of the zr axis as "zr direction".

  Also, in the following, for convenience of explanation, the upper side in FIG. 1 will be referred to as “upper” or “upper” and the lower side as “lower” or “lower”. Further, the base side in FIG. 1 is referred to as “proximal” or “upstream”, and the opposite side is referred to as “distal” or “downstream”. Further, the vertical direction in FIG. 1 is the vertical direction.

  In addition, in the present specification, “horizontal” includes not only the case of being completely horizontal but also the case of being inclined within ± 5 ° with respect to the horizontal. Similarly, in the present specification, “vertical” includes not only the case of being completely vertical but also the case of being inclined within ± 5 ° with respect to the vertical. Also, as used herein, "parallel" includes not only two lines (including an axis) or planes that are perfectly parallel to one another, but also inclined within ± 5 °. Also, as used herein, "orthogonal" includes not only when two lines (including axes) or planes are perfectly orthogonal to one another, but also when they are tilted within ± 5 °.

  A robot system 100 shown in FIG. 1 includes a robot 1, an end effector 19 (tool), an imaging unit 41, an image processing device 42, a robot control device 2 for controlling the operation (drive) of the robot 1 and the like, And a computer 5 capable of communicating with the control device 2 and the image processing device.

Hereinafter, each part which the robot system 100 has will be sequentially described.
<robot>
The robot 1 is a so-called six-axis vertical articulated robot, and is used, for example, in a manufacturing process for manufacturing a precision device etc., and various methods such as holding or transporting an object (not shown) such as a precision device or part Do the work of The robot 1 has a base 110 and a robot arm 10 (movable part) connected to the base 110. The object is not particularly limited as long as it is used in the work performed by the robot 1.

  The base 110 is a portion for attaching the robot 1 to an arbitrary installation point 70 such as a floor. The robot arm 10 includes an arm 11 (first arm), an arm 12 (second arm), an arm 13 (third arm), an arm 14 (fourth arm), an arm 15 (fifth arm), and an arm 16 (sixth) Arm). Further, the arm 15 and the arm 16 constitute a wrist. Further, the arm 16 has a disk shape, and the arm 16 can be provided (attached) with the end effector 19 (tool) in a removable manner. The arms 11 to 16 are connected in this order from the base 110 side to the end effector 19 side. Further, the arms 11 to 16 are rotatable around predetermined pivots (first to sixth pivots) (not shown) with respect to the adjacent arms or bases 110. That is, the base 110 and the arm 11 are connected via the joint 171 (joint). The arm 11 and the arm 12 are connected via a joint 172 (joint). The arm 12 and the arm 13 are connected via a joint 173 (joint). The arm 13 and the arm 14 are connected via a joint 174 (joint). The arm 14 and the arm 15 are connected via a joint 175 (joint). The arm 15 and the arm 16 are connected via a joint 176 (joint).

  The end effector 19 is not particularly limited, but in the present embodiment, an adsorption head (adsorption device) capable of adsorbing (holding) and releasing an object is used. In addition, as another configuration example of the end effector 19, for example, a hand capable of gripping (holding) and releasing an object can be mentioned. In addition, holding an object means holding the object so that the object can be moved or the attitude of the object can be changed, and includes, for example, gripping (gripping), adsorption, placement, etc. Be Also, the tip center of the end effector 19 is referred to as a tool center point P.

  Also, the end effector 19 may not be a component of the robot 1, or may be a component of the robot 1.

  Further, as shown in FIG. 2, the robot 1 has a drive unit 130 provided with a motor, a reduction gear, and the like for rotating one arm with respect to the other arm (or the base 110). As the motor, for example, a servomotor such as an AC servomotor or a DC servomotor can be used. As the reduction gear, for example, a planetary gear type reduction gear, a wave gear device, or the like can be used. The reduction gear may be omitted. Also, the robot 1 has an angle sensor 140 that detects the rotation angle of the rotation shaft of the motor or the reduction gear. As the angle sensor 140, for example, a rotary encoder or the like can be used. Also, the drive unit 130 and the angle sensor 140 are provided corresponding to each of the arms 11 to 16, and in the present embodiment, the robot 1 has six drive units 130 and six angle sensors 140.

  Further, although not shown, each drive unit 130 is electrically connected (hereinafter, also simply referred to as “connected”) to, for example, a motor driver incorporated in the base 110 shown in FIG. 1. Each drive unit 130 is controlled by the robot control device 2 via a corresponding motor driver. Further, each angle sensor 140 is electrically connected to the robot control device 2. Further, a drive unit (not shown) for driving the end effector 19 is controlled by the robot control device 2.

  The configuration of the robot 1 has been briefly described above. Such a robot 1 is controlled by a robot control device 2 described later. Thereby, the robot 1 can perform appropriate operation.

  Although not shown, the robot 1 may be provided with a force detection device (force detection unit) including, for example, a six-axis force sensor that detects a force (including a moment) applied to the end effector 19. . The force detection device is, for example, disposed between the arm 16 and the end effector 19 and electrically connected to the robot control device 2. By providing the force detection device, for example, it is possible to perform force control such as impedance control.

<Robot controller>
The robot control device 2 controls the operation of the robot 1. The robot control device 2 is configured by a robot controller that controls the functions of the units included in the robot 1, and is communicably connected to the robot 1, the computer 5, and the image processing device 42.

  The robot control device 2 and the robot 1 may be communicably connected in a wired manner by using, for example, a cable or the like, or may be communicably connected in a wireless manner. Also, the robot control device 2 may be separate from the robot 1, or part or all of the robot control device 2 may be incorporated in the robot 1 (for example, the base 110 or the like).

  Further, the robot control device 2 and the computer 5 may be communicably connected in a wired manner by using, for example, a cable or the like, or may be communicably connected in a wireless manner.

  Further, the robot control device 2 and the image processing device 42 may be communicably connected in a wired manner using, for example, a cable or the like, or may be communicably connected in a wireless manner.

  As shown in FIG. 2, the robot control device 2 includes a control unit 21 including a processor, a storage unit 22 including a memory and the like communicably connected to the control unit 21, and an external including an external interface (I / F). And an input / output unit 23 (reception unit). The external input / output unit 23 is an example of a reception unit of the robot control device 2. The components of the robot controller 2 are communicably connected to one another via various buses.

  The control unit 21 executes various programs and the like stored in the storage unit 22. As a result, control of the operation of the robot 1 and processing such as various calculations and judgments can be realized.

  The storage unit 22 stores (stores) various programs that can be executed by the control unit 21. In addition, the storage unit 22 can store various data accepted by the external input / output unit 23. The storage unit 22 includes, for example, a volatile memory such as a random access memory (RAM) or a non-volatile memory such as a read only memory (ROM). The storage unit 22 is not limited to the non-removable type, and may have a removable external storage device (not shown).

  The various programs include an operation program output from the computer 5 and a program for correcting or changing the operation program. As various data, the data etc. regarding the position attitude of tool center point P, the rotation angle of each arm 11-16, etc. are mentioned, for example.

  The external input / output unit 23 includes an external interface (I / F), and is used for each connection of the robot 1, the computer 5, and the image processing apparatus 42.

  Such a robot control device 2 controls the robot 1 based on, for example, an operation program created by the computer 5. As a result, using the operation program created by the computer 5, the robot 1 can be made to perform an appropriate operation.

  In addition to the configuration described above, the robot control device 2 may further have another configuration. Further, a display device having a display or the like, or an input device such as a mouse or a keyboard may be connected to the robot control device 2. In addition, various programs, data, etc. stored in the storage unit 22 may be stored in advance in the storage unit 22 or, for example, stored in a recording medium (not shown) such as a CD-ROM. It may be provided from this recording medium, or may be provided via a network or the like.

  Here, the robot control device of the present invention is configured by the robot control device 2, the computer 5, and the image processing device 42 in the present embodiment. Further, in the present embodiment, the control unit of the robot control device of the present invention is configured by the control unit 21 of the robot control device 2, the control unit 51 of the computer 5, and the angle calculation unit 421 of the image processing device 42.

<computer>
As the computer 5 shown in FIG. 2, for example, various computers such as a PC (Personal Computer) can be used, and they are communicably connected to the robot control device 2 and the image processing device 42.

  The computer 5 includes a control unit 51 including a processor, a storage unit 52 including a memory and the like communicably connected to the control unit 51, and an external input / output unit 53 (reception unit) including an external I / F (interface). ,including. The external input / output unit 53 is an example of a reception unit of the computer 5. The components of the computer 5 are communicably connected to one another via various buses.

  Further, the computer 5 and the image processing apparatus 42 may be communicably connected by a wired method using, for example, a cable or the like, or may be communicably connected by a wireless method.

  The control unit 51 executes various programs and the like stored in the storage unit 52. As a result, control of the image processing apparatus 42 and the like and processing such as various calculations and judgments can be realized.

  The storage unit 52 stores various programs that can be executed by the control unit 51. The storage unit 52 can also store various data accepted by the external input / output unit 53. The storage unit 52 is configured to include, for example, a volatile memory such as a random access memory (RAM) or a non-volatile memory such as a read only memory (ROM). The storage unit 52 is not limited to the non-removable type, and may have a removable external storage device (not shown).

  The external input / output unit 53 includes an external I / F (interface), and is used for each connection with the robot control device 2, the image processing device 42, the display device 31, and the input device 32. Therefore, the external input / output unit 53 has a function as a reception unit that receives an operation (instruction) of the input device 32 by the worker (user). Further, the external input / output unit 53 has a function as a mode receiving unit that receives selection of a predetermined mode among a plurality of modes. The external input / output unit 53 also has a function as an output unit that outputs signals regarding various screens to the monitor of the display device 31.

  In addition to the above-described configuration, the computer 5 may further have another configuration. Further, various programs and data stored in the storage unit 52 may be stored in advance in the storage unit 52, or may be stored in a recording medium (not shown) such as a CD-ROM, for example. It may be provided from this recording medium, or may be provided via a network or the like.

<Imaging unit>
The imaging unit 41 includes an imaging element (not shown), a lens group (not shown), and the like. In addition, the imaging unit 41 is attached (fixed) to an arbitrary installation place other than the robot 1 (different from the robot 1), for example, an installation place such as a floor, and can capture an upper side. (Pointing upwards). Further, the imaging device is not particularly limited, and examples thereof include a CCD image sensor, a CMOS image sensor, and the like. The imaging unit 41 performs imaging to generate an image (image data).

<Image processing device>
The image processing device 42 performs various types of image processing on an image (image data) obtained by imaging by the imaging unit 41. The image processing also includes, for example, calculation of an angle between straight lines. The image processing device 42 is communicably connected to the imaging unit 41.

  The image processing device 42 includes an angle calculation unit 421 including a processor, a storage unit 422 including a memory and the like communicably connected to the angle calculation unit 421, and an external input / output unit 423 including an external I / F (interface). And the reception unit). The external input / output unit 423 is an example of a reception unit of the image processing apparatus 42. The components of the image processing apparatus 42 are communicably connected to one another via various buses.

  Further, the image processing apparatus 42 and the imaging unit 41 may be communicably connected in a wired manner by using, for example, a cable or the like, or may be communicably connected in a wireless manner.

  The angle calculation unit 421 executes various programs and the like stored in the storage unit 422. In this way, it is possible to realize calculation of the angle between straight lines and the like. That is, the angle calculation unit 421 has a function of calculating an angle between straight lines included in an image obtained by imaging the target by the imaging unit 41.

  The storage unit 422 stores various programs that can be executed by the angle calculation unit 421. The storage unit 422 can also store various data accepted by the external input / output unit 423. The storage unit 422 is configured to include, for example, a volatile memory such as a random access memory (RAM) or a non-volatile memory such as a read only memory (ROM). The storage unit 422 is not limited to the non-removable type, and may have a removable external storage device (not shown).

  The external input / output unit 423 includes an external I / F (interface), and is used for each connection with the imaging unit 41, the robot control device 2 and the computer 5. The external input / output unit 423 has a function as an image receiving unit that receives an image (image data) obtained by imaging an object by the imaging unit 41.

  In addition to the above-described configuration, the image processing apparatus 42 may further include another configuration. In addition, various programs, data, etc. stored in the storage unit 422 may be stored in advance in the storage unit 422 or, for example, stored in a recording medium (not shown) such as a CD-ROM. It may be provided from this recording medium, or may be provided via a network or the like.

<Display device and input device>
The display device 31 (display unit) illustrated in FIG. 2 includes a display, and has, for example, a function of displaying various screens. The display device 31 is not particularly limited, and examples thereof include a direct-view display device such as a liquid crystal display device and an organic EL display device, and a projection display device such as a projector. The display device 31 is connected to the computer 5, but can be connected to the robot control device 2. In addition, two display devices 31 can be prepared, and the display devices 31 can be connected to the computer 5 and the robot control device 2. Here, the case where the display device 31 is connected to the computer 5 will be described as an example.

  The input device 32 (input unit) includes, for example, a mouse, a keyboard, and the like. Although this input device 32 is connected to the computer 5, it can also be connected to the robot control device 2. In addition, two input devices 32 can be prepared, and the input devices 32 can be connected to the computer 5 and the robot control device 2. Here, the case where the input device 32 is connected to the computer 5 will be described as an example. By operating the input device 32, the worker can instruct (input) various processes and the like to the computer 5.

  Specifically, the operator clicks on the various screens (windows etc.) displayed on the display device 31 with the mouse of the input device 32, and inputs characters and numbers with the keyboard of the input device 32. Can instruct the computer 5. Hereinafter, the instruction (input by the input device 32) by the operator using the input device 32 is also referred to as "operation instruction". The operation instruction includes a selection operation of selecting desired content from the content displayed on the display device 31 by the input device 32, and an input instruction of inputting characters, numbers, and the like by the input device 32. The inputs also include selections.

Note that one display device 31 and one input device 32 may be connected to the computer 5, or a plurality of each may be connected. Further, instead of the display device 31 and the input device 32, a display input device (not shown) having the functions of the display device 31 and the input device 32 may be used. For example, a touch panel or the like can be used as the display input device.
The basic configuration of the robot system 100 has been briefly described above.

<< Operation of robot system etc. >>
Next, the procedure of the work performed by the worker and the operation of the robot system 100 will be described.

  Further, as shown in FIG. 3, as an operation performed by the robot 1, the end effector 19 adsorbs (holds) the object 71, moves the object 71 to a predetermined position, and moves the hole 721 of the object 72. The operation of inserting will be described as an example. Although the objects 71 and 72 are not particularly limited, respectively, the shape of the object 71 and the shape of the hole 721 of the object 72 are respectively rectangular (square) in the present embodiment. The work performed by the robot 1 is not limited to the above.

  Further, in the robot 1, a plurality of tool coordinate systems (robot coordinate systems) having three axes orthogonal to each other are set, and the tool coordinate systems are associated with each other. As an example of the tool coordinate system, a three-dimensional coordinate system having xr axis, yr axis and zr axis shown in FIG. 1, a three-dimensional coordinate system having an end effector 19 tip (tool center point P) as an origin It can be mentioned.

  Further, in the imaging unit 41 (field of view of the imaging unit 41) (an image obtained by imaging by the imaging unit 41), an imaging unit coordinate system (image coordinate system) having two axes orthogonal to each other is set. Then, calibration of the imaging unit 41 is completed. That is, a predetermined tool coordinate system, in this embodiment, a tool coordinate system (not shown) having a tool center point P as an origin and an imaging unit coordinate system (not shown) are associated with each other. Do. Thereby, information on the position of each part (each point) in an image (captured image) obtained by imaging by the imaging unit 41 can be acquired as coordinates (robot coordinates) in the tool coordinate system.

<Operation of robot during mass production (work)>
As shown in FIG. 3, the robot 1 adsorbs the target 71 supplied from the target supply unit 77 by the end effector 19. The position and the posture of the object 71 absorbed by the end effector 19 vary somewhat.

  On the other hand, the target 72 is transported by the conveyor 76 (target transport unit). Then, the object 72 is stopped by the lock mechanism 761 at a position where the object 71 is inserted into the hole 721 (hereinafter, also referred to as “assembly position”). That is, the object 72 is positioned by the lock mechanism 761 so that the hole 721 is in a fixed position (angle).

  Next, the robot 1 moves the object 71 to a predetermined position (constant position) on the imaging unit 41, and the imaging unit 41 images the object 71 from below. Then, the robot control device 2 and the image processing device 42 calculate, from the obtained image, deviations in the two axial directions (xr direction, yr direction) orthogonal to each other and the rotational directions about the zr axis, and correct the deviations. The operation of the robot 1 is controlled. The robot 1 moves the object 71 to the assembly position and inserts the object 71 into the hole 721 of the object 72.

<Image processing>
First, the screen WD1 shown in FIG. 4 is displayed on the display device 31.

  Further, the imaging unit 41 is installed so that the vertical direction is substantially the same as when the object 71 is viewed from above. In this case, the image of the object 71 (see FIG. 4) obtained by imaging by the imaging unit 41 is opposite to the left and right in FIG. 4 when the object 71 is viewed from above.

  In this image processing sequence, the positions (CX, CY) of the center of the object 71 (rectangle) orthogonal to each other by combining straight line detection about four sides of the object 71 and geometrical calculation are combined. Ask for In straight line detection, the side of the object 71, that is, the first straight line is detected using the frame 8 shown in FIGS. 4 and 5, and this first straight line and the imaging unit coordinate system on the image (image coordinates Determine the angle between the second straight line along the coordinate axis in the system). At this time, the coordinate axis in the imaging unit coordinate system (image coordinate system) may be the x-axis or the y-axis. Further, as the angle of the object 71, one angle (A) between the first straight line and the second straight line in the imaging unit coordinate system (image coordinate system) in the straight line detection is used.

  As described above, the information of the position of each part (each point) in the image obtained by imaging by the imaging unit 41 can be acquired as robot coordinates. Further, CX and CY can be converted to values (unit: mm) in robot coordinates, and in the present embodiment, in coordinates in a three-dimensional coordinate system having xr axis, yr axis and zr axis shown in FIG. is there. In addition, A is an angle (unit: °) measured counterclockwise with respect to a second straight line along the x axis in the image pickup unit coordinate system (image coordinate system) on an image. ). Further, A may be an angle measured clockwise between the second straight line and the first straight line in the imaging unit coordinate system (image coordinate system). In addition, A may be an angle between an arbitrary plane in a tool coordinate system (robot coordinate system) having three axes orthogonal to each other.

<Preparation for adjustment of deviation>
At the time of adjustment before mass production, execute the following steps.

  1. The object 71 is manually inserted into the hole 721 of the object 72 stopped by the lock mechanism 761 on the conveyor 76.

  2. The robot 1 is operated such that the end effector 19 is located at the center of the object 71, and the end effector 19 adsorbs the object 71. The attitude P1 of the robot arm 10 of the robot 1 at this time is stored.

  3. The robot 1 is operated so that the object 71 is located near the center of the field of view of the imaging unit 41. The attitude P2 of the robot arm 10 of the robot 1 at this time is stored.

  4. The object 71 is imaged by the imaging unit 41, and the angle calculation unit 421 of the image processing device 42 performs image processing using the obtained image (image data), and the robot coordinates CX0 and CY0 of the center of the object 71 An angle A0 measured counterclockwise between a straight line corresponding to at least one side of the four sides of the object 71 on the image and a straight line along the x axis in the image coordinate system is determined. The CX0, CY0, A0 are the reference position and the reference angle of the object 71. Note that CX0 and CY0 are coordinates in a three-dimensional coordinate system having the xr axis, the yr axis, and the zr axis shown in FIG.

Adjustment of deviation during mass production
The adjustment of the deviation at the time of mass production performs the following steps.

  1. The end effector 19 of the robot 1 adsorbs the object 71 and moves the object 71 into the field of view of the imaging unit 41. The posture of the robot arm 10 of the robot 1 at this time is set to the posture P2.

  2. The object 71 is imaged by the imaging unit 41, and the angle calculation unit 421 of the image processing device 42 performs image processing using the obtained image (image data), and the robot coordinates CX1 and CY1 of the center of the object 71 An angle A1 measured counterclockwise between a straight line corresponding to at least one side of four sides of the object 71 on the image and a straight line along the x axis in the image coordinate system is determined. The CX1, CY1 and A1 are the current position and the current angle of the object 71. Note that CX1 and CY1 are coordinates in a three-dimensional coordinate system having the xr axis, the yr axis, and the zr axis shown in FIG.

  Deviations of the current position and the current angle with respect to the reference position of the object 71 and the reference angle are represented by the following equations (1), (2), and (3).

ΔX1 = CX1−CX0 (1)
ΔY1 = CY1-CY0 (2)
ΔA = A1−A0 (3)
In mass production, the above operation is performed first.

  Here, if the angular deviation ΔA on the image is the angular deviation in robot coordinates, the positive and negative are opposite. Therefore, when the end effector 19 of the robot 1 is rotated by an angle of ΔA, the angle (posture) of the object 71 becomes the same as the angle (posture) of the object 71 at the reference position. However, the center of the object 71 moves ΔX 2 and ΔY 2 represented by the following equations (4) and (5).

ΔX 2 = cos (ΔA) * ΔX 1 -sin (ΔA) * ΔY 1 (4)
ΔY2 = sin (ΔA) * ΔX1 + cos (ΔA) * ΔY1 (5)
ΔX = ΔX1 + ΔX2 (6)
ΔY = ΔY1 + ΔY2 (7)

  Therefore, if the robot 1 is operated so as to cancel the deviation of ΔX and ΔY of the center of the object 71 shown by the above equations (6) and (7), the object 71 coincides with the reference position Corrections can be made. For that purpose, the end effector 19 (object 71) of the robot 1 may be moved by -.DELTA.X, -.DELTA.Y.

3. At the time of mass production, the robot control device 2 obtains ΔX, ΔY and ΔA, and makes corrections similar to the above with respect to the posture P1 of the robot arm 10 until the robot 1 moves the object 71 to the assembly position. Then, the object 71 is inserted into the hole 721 of the object 72 by performing −ΔX, −ΔY) and ΔA ′ ′.
At the time of adjustment before mass production, the computer 5 obtains ΔX, ΔY and ΔA.

Frame used for straight line detection
Next, when the detection of the straight line 26 of the object 71 (straight line detection) is performed, the frame 8 indicating the detection area will be described.

  As shown in FIG. 5, an imaging unit coordinate system having an x axis and ay axis (two axes) orthogonal to each other in the imaging unit 41 (field of view of the imaging unit 41) (image obtained by imaging by the imaging unit 41). 25 (image coordinate system) is set.

  Further, the shape of the object 71 is not particularly limited, but in the present embodiment, it has a rectangular shape (square shape). Further, the area inside the object 71 is referred to as “dark (dark area)”, and the area outside the object 71 is referred to as “bright (bright area)”. In this example, a predetermined long side of the object 71 is a straight line 26 to be detected.

  The frame portion 8 is also referred to as a “line finder”, and in the present embodiment, it has a rectangular (square) frame 81 and a plurality of arrows 82 (edge detection lines) arranged in the frame 81. doing. The short sides 85 and 86 of the frame 81 also double as arrows 82 (edge detection lines). And each arrow 82 is arrange | positioned in parallel with the short sides 85 and 86 at equal intervals, and has faced the long side 84 side (the same direction). The frame 8 may have another configuration.

  In addition, when performing straight line detection, the frame portion 8 is arranged such that each arrow 82 intersects with the straight line 26 to be detected. Further, in the present embodiment, the frame portion 8 is arranged such that each arrow 82 points in the direction from "bright" to "dark". The frame 8 may be arranged such that each arrow 82 points in the direction from "dark" to "bright".

  Further, an intersection point of the straight line 26 and the short side 85 is a start point 27, and an intersection point of the straight line 26 and the short side 86 is an end point 28, and an arrow 29 from the start point 27 to the end point 28 is assumed. The arrow 29 indicates the direction and direction of the straight line 26. Then, an angle θ measured counterclockwise between the straight line 26 and the straight line along the x-axis is obtained.

<Image processing property (parameter) settings>
The straight line detection properties include "Directed" and "AngleType". The “Directed property” and the “AngleType property” correspond to “specifying an angle expression method” in the robot system 100. )

(1) Angle Expression of Angle Result by Directed Property The value of the Directed property includes “True” and “False”. The second mode is when Directed is set to "True", and the third mode is when Directed is set to "False". In this embodiment, a plurality of modes including the second mode and the third mode are provided as modes for obtaining a detection angle.

  In the second mode set to True, it is assumed that the straight line detected on the image has an orientation, and the angle calculation unit 421 of the image processing device 42 sets a 360 ° range (for example, Return at 0 ° or more and less than 360 °). For example, the angle θ measured counterclockwise between two straight lines 261, 262 in the same direction and different directions and a straight line along the x-axis is 330 ° (see FIG. 7) and 150 ° (see In the case of FIG. 8), it is distinguished between 330 ° and 150 °. That is, the detection angle of the straight line 261 shown in FIG. 7 is expressed as 330 °, and the detection angle of the straight line 262 shown in FIG. 8 is expressed as 150 °.

  In the case of the third mode set to False, the straight line detected on the image has no direction, and the angle calculation unit 421 reverses the line between the straight line and the straight line along the x axis in the image coordinate system. As a detection angle measured clockwise, it returns in the range of 180 ° (for example, 0 ° or more and less than 180 °, or −90 ° or more and less than 90 °). If this setting is made, the frame portion 8 is rotated 180 degrees on the image and moved to the opposite side of the rectangular object (quadrilateral) 71, and the straight line detected on the image and the x axis in the image coordinate system Even when an angle measured counterclockwise between a straight line and the straight line is detected, the same angle is detected. As a result, even in that case, it is possible to prevent the tip of the robot arm 10 of the robot 1 from rotating at a large angle and damaging the cable provided on the robot arm 10.

  That is, when the angle measured counterclockwise between the straight line detected on the image and the straight line along the x-axis in the image coordinate system is within a predetermined range, that angle is taken as a detection angle. Further, when the angle of the straight line is not within a predetermined range, if the correction angle obtained by subtracting or adding 180 ° to the angle of the straight line is within a predetermined range, the correction angle is taken as a detection angle. The predetermined range is not particularly limited, but is preferably 0 ° or more and less than 180 °, or preferably -90 ° or more and less than 90 °.

  For example, an angle θ measured counterclockwise between two straight lines 261, 262 in the same direction and different directions and a straight line along the x axis in the image coordinate system is 330 ° (see FIG. 7). , 150 ° (see FIG. 8), it does not distinguish between 330 ° and 150 °. That is, the detection angle of the straight line 261 and the detection angle of the straight line 262 are both expressed as 330 ° (see FIGS. 9 and 10) or 150 ° (see FIGS. 11 and 12).

  Here, when setting the mode of the straight line detection, the operator uses the input device 32 and performs predetermined operations such as selection of the value of the Directed property and selection of the value of the AngleType property described later on the screen DW1 shown in FIG. Give an operation instruction. When the external input / output unit 53 of the computer 5 receives the operation instruction, the control unit 51 sets the line detection mode to the instructed mode.

(2) Angle Expression of Angle Result by Angle Type Property There are “Absolute” and “Nearest” as values of Angle Type property. The case where Angle Type is set to “Nearest” is the first mode, and the case where Angle Type is set to “Absolute” is the fourth mode.

  In the fourth mode set to Absolute, the angle calculation unit 421 returns a detection angle of a straight line in a range of 0 ° or more and less than 360 °.

  In the case of the first mode set to Nearest, the angle calculation unit 421 returns the angle closest to the angle (predetermined angle) set in the AngleStart property described later as the detection angle of the straight line.

  That is, the angle calculation unit 421 determines the angle between a straight line having a predetermined angle with a straight line along the x axis in the imaging unit coordinate system 25 (image coordinate system) and a straight line detected on the image. When the absolute value is the smallest, the angle of the straight line detected on the image is taken as the detection angle of the straight line. As a result, it is possible to prevent the tip of the robot arm 10 of the robot 1 from rotating at a large angle and damaging the cable provided on the robot arm 10.

In practice, in order to determine the angle closest to the predetermined angle, the following is performed.
First, the angle calculation unit 421 sets the absolute value of the angle between the straight line 26 detected on the image and the straight line having a predetermined angle between the straight line along the x axis in the image coordinate system to a predetermined range. If it is inside, the angle between the straight line 26 and the straight line along the x axis in the image coordinate system is taken as the detection angle. In addition, when the absolute value of the angle between the straight line 26 and the straight line having a predetermined angle between the straight line 26 and the straight line along the x axis in the image coordinate system is not within the predetermined range, the angle calculation unit 421 A correction angle obtained by subtracting or adding 360 ° to the angle between the straight line 26 and the straight line along the x axis in the image coordinate system is defined as a detection angle. Thereby, between the straight line 26 having the smallest absolute value of the angle between the straight line along the x axis and the straight line along the x axis in the image coordinate system, and the straight line along the x axis in the image coordinate system Angle can be easily and quickly determined.

  Here, the lower limit value and the upper limit value of the predetermined range are not particularly limited, and examples thereof include -50 ° and 180 °.

  For example, as shown in FIG. 13, the angle between the straight line 26 and the straight line along the x axis in the image coordinate system, ie, an angle θ1 of Directed of “True” and “330 °” (see FIG. 13) If AngleStart is "0 °", it is expressed as a clockwise angle θ2 from the straight line along the x axis in the image coordinate system, that is, "-30 °", and if AngleStart is "180 °", the image coordinates It is expressed as a counterclockwise angle θ1 from the straight line along the x-axis in the system, that is, “330 °”.

  Here, for example, the property of straight line detection Directed is set to “False”, the AngleType is “Nearest”, the AngleStart is “0 °”, and the AngleRange is “30 °”. Angle Range is a detection range of a straight line angle, and “30 °” is “± 30 °”.

  With this setting, the image processing sequence is executed, and between the coordinates of the center point of the object 71, the straight line corresponding to at least one of the four sides of the object 71, and the straight line along the x axis in the image coordinate system Find the angle of and adjust the deviation during the mass production. If the adjustment at the time of mass production is performed with AngleType set to “Absolute”, the tip of the robot arm 10 may rotate by nearly 360 °, but with the above setting, such rotation is suppressed can do.

Also, specific examples of straight line detection properties are shown below.
For example, as shown in FIG. 6, Property is “Value”, AngleType is “Absolute”, AngleStart is “0”, AngleRange is “180”, Directed is “False”, NumberOfEdges is “5”, Polarity is “LightToDark” , Set SearchWidth to "3".

  AngleType is “select angle expression”. Also, AngleStart is a "predetermined angle". Also, AngleRange is “range of angle detection”. Moreover, Directed is "presence or absence". Also, NumberOfEdges is “the number of edge detection lines”. Also, Polarity is the “direction of edge contrast to be detected”, for example, “light to dark” and “dark to light”. Also, SearchWidth is “width of edge detection line”. Edges are detected after averaging the light and dark within this width.

<Description of combination of parameters>
As described above, there are Directed and AngleType in the angle expression, but it is also possible to combine the parameters of Directed and the parameters of AngleType.

  In this case, when Directed is set to True and AngleType is set to Absolute, and when Directed is set to True and AngleType is set to Nearest, Directed is set to False and AngleType is set to Absolute. There are four combinations, one for setting Directed to “False” and one for setting AngleType to “Nearest”.

  As described above, according to the robot system 100, the robot 1 can be controlled appropriately and the robot 1 can be operated. As a result, it is possible to prevent the tip of the robot arm 10 of the robot 1 from rotating at a large angle and damaging the cable provided on the robot arm 10.

  As described above, the robot control device configured by the robot control device 2, the computer 5, and the image processing device 42 is a device that controls the robot 1, and receives an image obtained by imaging the object 71. An input / output unit 423 (image reception unit), an angle calculation unit 421 that calculates an angle between a straight line 26 included in the image and a straight line along a coordinate axis in the imaging unit coordinate system 25 (image coordinate system); And an external input / output unit 53 (mode reception unit) that receives selection of a predetermined mode among the modes. In addition, the plurality of modes are absolute values of the first angle between a straight line having a predetermined angle between the straight line 26 included in the image and the straight line along the coordinate axis in the imaging unit coordinate system 25 (image coordinate system) Is the smallest, the first mode to be calculated by the angle calculation unit 421 so that the angle between the straight line 26 and the straight line along the coordinate axis in the imaging unit coordinate system 25 (image coordinate system) is the detection angle of the straight line 26 Including.

  According to such a robot control device, the robot 1 can be controlled appropriately. As a result, it is possible to prevent the tip of the robot arm 10 of the robot 1 from rotating at a large angle and damaging the cable provided on the robot arm 10.

  Further, in the plurality of modes, the correction angle obtained by subtracting or adding 180 ° to the angle between the straight line 26 included in the image and the straight line along the coordinate axis in the imaging unit coordinate system 25 (image coordinate system) is a predetermined range If it is inside, it includes the second mode in which the correction angle is the detection angle. Thereby, in the second mode, the straight line 26 included in the image and the imaging unit coordinate system 25 (image coordinate system) are distinguished without distinguishing the case where the direction of the straight line 26 included in the image is reverse to the predetermined direction. Calculate the angle between the straight line along the coordinate axis in the axis of the robot arm 10 so that the tip of the robot arm 10 of the robot 1 is prevented from damaging the cable provided on the robot arm 10 by a large angle. Can.

  Moreover, it is preferable that a predetermined range is 0 degree or more and less than 180 degrees, or -90 degrees or more and less than 90 degrees. Thereby, in the second mode, the straight line 26 included in the image and the imaging unit coordinate system 25 (image coordinate system) are distinguished without distinguishing the case where the direction of the straight line 26 included in the image is reverse to the predetermined direction. Calculate the angle between the straight line along the coordinate axis in the axis of the robot arm 10 so that the tip of the robot arm 10 of the robot 1 is prevented from damaging the cable provided on the robot arm 10 by a large angle. Can.

  Further, in the first mode, the angle calculation unit 421 sets a line between the straight line 26 included in the image and a straight line along a coordinate axis in the imaging unit coordinate system 25 (image coordinate system) to a predetermined angle. If the absolute value of the first angle of the first angle is within the predetermined range, the straight line 26 included in the image used to calculate the absolute value of the first angle and the coordinate axis in the imaging unit coordinate system 25 (image coordinate system) An angle between the straight line and the straight line is a detection angle. As a result, the straight line 26 having the smallest absolute value of the first angle with the straight line having a predetermined angle with the straight line along the coordinate axis in the imaging unit coordinate system 25 (image coordinate system) and the imaging unit coordinate system 25 The angle between the straight line along the coordinate axis in the (image coordinate system) can be determined easily and quickly.

  Further, in the first mode, the angle calculation unit 421 sets the absolute value of the first angle between the straight line having a predetermined angle with the straight line along the coordinate axis in the image coordinate system 25 (image coordinate system) If it is not within the predetermined range, 360 degrees is subtracted from the angle between the straight line 26 used to calculate the absolute value of the first angle and the straight line along the coordinate axis in the imaging unit coordinate system 25 (image coordinate system) Alternatively, the correction angle obtained by adding is used as a detection angle. Thereby, the straight line 26 having the smallest absolute value of the first angle between the straight line along the coordinate axis in the imaging unit coordinate system 25 and the straight line having a predetermined angle with the straight line and the imaging unit coordinate system 25 (image coordinate system) The angle between the straight line along the coordinate axis at can be determined easily and quickly.

  Further, the robot 1 has a robot arm 10 and is controlled by a robot control device including a robot control device 2, a computer 5 and an image processing device 42.

  According to such a robot 1, an appropriate operation can be performed by the control of the robot control device.

  The robot system 100 also includes a robot 1 having a robot arm 10, an imaging unit 41 for imaging an object 71, a robot control device 2 for controlling the robot 1, a computer 5, and an image processing device 42. A device.

  According to such a robot system 100, the robot 1 can be controlled appropriately. As a result, it is possible to prevent the tip of the robot arm 10 of the robot 1 from rotating at a large angle and damaging the cable provided on the robot arm 10.

  FIG. 14 is a block diagram for describing the embodiment centering on hardware (processor).

  FIG. 14 shows the overall configuration of a robot system 100A in which the robot 1, the controller 61, and the computer 62 are connected. Control of the robot 1 may be executed by reading a command in the memory by a processor in the controller 61 or may be executed by reading a command in the memory by a processor present in the computer 62 and executed through the controller 61. Good.

<Modification 1>
FIG. 15 is a block diagram showing another example 1 (modified example 1) of the robot system of the present invention.

  FIG. 15 shows the entire configuration of a robot system 100B in which a computer 63 is directly connected to the robot 1. The control of the robot 1 is directly executed by reading a command in the memory by a processor present in the computer 63.

<Modification 2>
FIG. 16 is a block diagram showing another example 2 (modified example 2) of the robot system of the present invention.

  FIG. 16 shows the overall configuration of a robot system 100C in which a robot 1 having a controller 61 incorporated therein and a computer 66 are connected and the computer 66 is connected to a cloud 64 via a network 65 such as a LAN. The control of the robot 1 may be executed by reading a command in the memory by a processor present in the computer 66, or may be executed by reading a command in the memory via the computer 66 by a processor present in the cloud 64. May be

  Further, in the robot systems 100A, 100B, and 100C, each processor may be configured by one device or may be configured by a plurality of devices, that is, divided into a plurality of unit processors. May be

  The robot control apparatus, robot and robot system of the present invention have been described above based on the illustrated embodiment, but the present invention is not limited to this, and the configuration of each part is an arbitrary one having the same function. It can be replaced by one of the configuration. Also, any other component may be added.

  In the embodiment described above, a six-axis vertical articulated robot is exemplified as the robot, but the robot is not limited to this, and, for example, a horizontal articulated robot such as a scalar robot, a leg type walking robot It may be a robot of another form such as a (traveling) robot. Moreover, the said robot is not limited to a single arm robot, For example, other robots, such as a double arm robot, may be used. Therefore, the number of robot arms (movable parts) is not limited to one, and may be two or more. Further, the number of arms included in the robot arm (movable part) is six in the above-described embodiment, but may be one to five or seven or more.

DESCRIPTION OF SYMBOLS 1 ... Robot, 2 ... Robot control apparatus, 5 ... Computer, 8 ... Frame part, 10 ... Robot arm, 11 ... Arm, 12 ... Arm, 13 ... Arm, 14 ... Arm, 15 ... Arm, 16 ... Arm, 19 ... End effector, 21: control unit, 22: storage unit, 23: external input / output unit, 25: imaging unit coordinate system, 26: straight line, 27: starting point, 28: end point, 29: arrow, 31: display device, 32: Input device, 41: imaging unit, 42: image processing device, 51: control unit, 52: storage unit, 53: external input / output unit, 61: controller, 62: computer, 63: computer, 64: cloud, 65: network , 66: computer, 70: installation location, 71: target, 72: target, 76: conveyor, 77: target supply unit, 81: frame, 82: arrow, 83, long side, 4 long side 85 short side 86 short side 100 robot system 100A robot system 100B robot system 100C robot system 110 base 130, driving unit 140 angle sensor 171 ... joint, 172 ... joint, 173 ... joint, 174 ... joint, 175 ... joint, 176 ... joint, 261 ... straight line, 262 ... straight line, 421 ... angle calculation unit, 422 ... storage unit, 423 ... external input / output unit, 721 ... hole, 761 ... locking mechanism, A0 ... angle, A1 ... angle, CX0 ... robot coordinates, CX1 ... robot coordinates, DW1 ... screen, P ... tool center point, P1 ... attitude, P2 ... attitude,
WD1 ... screen, θ ... angle, θ1 ... angle, θ2 ... angle

Claims (7)

A robot controller for controlling a robot,
An image reception unit that receives an image obtained by imaging an object;
An angle calculation unit that calculates an angle between a first straight line included in the image and a second straight line along a coordinate axis in a coordinate system of the image;
A mode reception unit that receives selection of a predetermined mode among a plurality of modes;
Equipped with
The plurality of modes calculate a first angle between a third straight line having a predetermined angle with the second straight line and the first straight line, and the absolute value of the first angle is most A robot control apparatus comprising: a first mode for causing the angle calculation unit to calculate an angle between the small first straight line and the second straight line as a detection angle of the first straight line .   The plurality of modes include the correction angle when the correction angle obtained by subtracting or adding 180 ° from the angle between the first straight line and the second straight line is within a predetermined range. The robot controller according to claim 1, further comprising a second mode.   The robot control device according to claim 2, wherein the predetermined range is 0 ° or more and less than 180 °, or -90 ° or more and less than 90 °.   In the first mode, when the absolute value of the first angle is within a predetermined range, the angle calculation unit uses the first straight line and the second straight line used for calculating the absolute value of the first angle. The robot control device according to claim 1, wherein an angle between the straight line and the straight line is the detection angle.   In the first mode, when the absolute value of the first angle is not within a predetermined range, the angle calculation unit uses the first straight line and the second straight line used for calculating the absolute value of the first angle. The robot control device according to claim 1 or 4, wherein a correction angle obtained by subtracting or adding 360 ° to an angle between a straight line and the straight line is used as the detection angle. Has a robot arm,
A robot controlled by the robot control device according to any one of claims 1 to 5. A robot having a robot arm,
An imaging unit for imaging an object;
The robot control device according to any one of claims 1 to 5, which controls the robot.

Images