JP2012228756A - Robot control method, robot control device, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a robot control method for easily obtaining information about the operation of the robot.SOLUTION: The robot control method is for controlling the robot 1 in order for the robot 1 to attach a screw (member) 21 to a workpiece 10, and includes: a moving step of making the robot 1 move a camera 6 to the position of the workpiece 10; an image capturing step of obtaining the captured image of the workpiece 10 captured by the camera 6; a detection step of detecting a marker 15 that the workpiece 10 has from the captured image; an analysis step of obtaining kind information of the screw 21 by analyzing the marker 15; and a working step of making the robot 1 attach the screw 21 to the workpiece 10 on the basis of the kind information.

Description

  The present invention relates to a robot control method for controlling the operation of the robot, a robot control device for controlling the robot based on the robot control method, a program that can be installed in the robot control device in accordance with the robot control method, , Regarding.

  Conventionally, as a program generation method for a robot, various data such as master data, teaching point data, and posture data are used, and the operation of the robot with respect to the target workpiece is defined by means of combining, rearranging, and converting the data. A method for generating a program is disclosed. According to this method, teaching to the robot is possible with only the drawing, and the time for generating the program can be shortened (for example, Patent Document 1).

  Also, register the image of the target workpiece as a master image pattern, perform pattern matching between this master image pattern and each captured target workpiece image, and only when pattern matching is successful for all target workpiece images, A method for outputting the position and orientation of each target workpiece is disclosed. According to this method, erroneous detection can be reduced, the recognition accuracy of the target workpiece can be further increased, and the position and orientation can be detected with high accuracy (for example, Patent Document 2).

JP-A-10-222219 JP 2010-32258 A

  However, in Patent Document 1, it is necessary to construct a large amount of database. In addition, the necessary data in actual work may vary depending on the work position, etc. In that case, consistency with the database must be taken, and the work of taking this consistency is a very complicated work, There was a problem. In Patent Document 2, although it is possible to obtain workpiece information in which the position and orientation of the target workpiece are detected with high accuracy, operation information related to the actual work of the robot with respect to the target workpiece cannot be obtained. Therefore, there is a problem that it is necessary to obtain the operation information from the work information to be consistent with the work information.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following application examples or forms.

  [Application Example 1] A robot control method according to this application example is a method for controlling a robot and attaching a member to a workpiece, the moving step of moving an imaging device to the position of the workpiece, and the imaging device An imaging step of acquiring an image of the workpiece taken, a detecting step of detecting a marker of the workpiece from the imaging, an analyzing step of analyzing the marker to acquire type information of the member, and the type And an operation step of performing an operation of attaching the member to the workpiece based on the information.

  According to this robot control method, the robot is controlled, and the imaging of the workpiece is first acquired through the moving step and the imaging step, and then the marker is detected from the acquired imaging in the detection step. This marker is arranged on the side of the work to which the member is attached, and has type information indicating what the member is, for example, a screw, a pin, a nut, a bush or the like. In the analysis step, type information is acquired by analyzing the marker. Then, based on this type information, in the work step, the robot performs the work of attaching the member to the workpiece. As described above, the robot control method easily obtains all or a part of the information for the robot to work from the marker placed on the workpiece each time, so the robot must store it in advance. It is possible to reduce the amount of information that must not be. In addition, since the robot work can be easily changed by changing the marker, the robot can quickly change the work and efficiently perform various work.

  Application Example 2 In the robot control method according to the application example described above, in the analysis step, it is preferable that the type information including information related to the attachment method of the member is acquired from the marker.

  According to this method, the type information acquired in the analysis step includes information such as how to attach the member to the workpiece in addition to information indicating what the member is. Examples of the information on the attachment method include, for example, when the member is a screw, the insertion direction of the workpiece into the screw hole, the tightening torque, and the like. This makes it possible to further reduce the amount of information that the robot has to store in advance, and to change the work of the robot, the information stored in the robot etc. by changing the marker Can be done more easily with little modification.

  Application Example 3 In the robot control method according to the application example described above, the marker has a two-dimensional code that is disposed in the vicinity of an attachment portion where the member is attached to the workpiece and includes the type information. Is preferred.

  According to this method, since the marker is arranged in the vicinity of the mounting portion, it is only necessary to move the imaging device to the approximate position of the workpiece in the moving step, and the analysis step is easy from the imaging acquired in the imaging step. The type information can be acquired by detecting the marker. In addition, since the marker holds the type information in the form of a two-dimensional code, it can have a large amount of information, and can have necessary and sufficient information even in a narrow space.

  Application Example 4 A robot control device according to this application example is for controlling a robot and attaching a member to a workpiece, and a moving unit that moves the imaging device to the position of the workpiece, and the imaging device An imaging unit that acquires an image of the workpiece, a detection unit that detects a marker of the workpiece from the imaging, an analysis unit that analyzes the marker and acquires type information of the member, and the type And a working unit for performing work for attaching the member to the workpiece based on the information.

  According to this robot control apparatus, imaging is first acquired by the control of the robot by the moving unit and the imaging unit, and then a marker is detected from the acquired imaging by the detection unit. This marker is arranged on the side of the work to which the member is attached, and has type information indicating what the member is, for example, a screw, a pin, a nut, a bush or the like. The analysis unit acquires the type information by analyzing the marker. Then, based on this type information, the working unit controls the robot to perform the work of attaching the member to the work. As described above, the robot control apparatus is configured to easily obtain all or a part of information for the robot to work from the marker arranged on the work each time. It is possible to reduce the amount of information that should not be handled. Also, the work content of the robot can be easily changed by mainly changing the marker.

  Application Example 5 A program according to this application example is for executing control for a robot to attach a member to a workpiece, the moving step of moving the imaging device to the position of the workpiece, and the imaging device An imaging step of acquiring an image of the workpiece taken, a detecting step of detecting a marker of the workpiece from the imaging, an analyzing step of analyzing the marker to acquire type information of the member, and the type Based on the information, the robot is caused to execute an operation step of performing an operation of attaching the member to the workpiece.

  According to this program, the robot is controlled so that an image of the workpiece is first acquired by the movement step and the imaging step, and then a marker is detected from the acquired imaging by the detection step. This marker is arranged on the side of the work to which the member is attached, and has type information indicating what the member is, for example, a screw, a pin, a nut, a bush or the like. In the analysis step, the type information is obtained by analyzing the marker. Based on this type information, in the work step, the robot is caused to perform a work of attaching a member to the work. In this way, in the program, all or a part of the information for causing the robot to perform work can be easily obtained from the marker arranged on the work each time. It is possible to reduce the amount of information that must be stored in advance. Moreover, since the change of the robot work content can be obtained from the changed marker, it is possible to perform the control while suppressing the influence on the program itself as much as possible.

The perspective view which shows the structural example which concerns on one form of the operation | work by a robot. The block diagram which shows the structure of the control apparatus of a robot. The flowchart which shows the procedure of the operation | work by a robot. (A) The perspective view which shows the state of imaging | photography with a camera, (b) The perspective view which shows the holding state of a screw, (c) The perspective view which shows the attachment state of a screw.

Hereinafter, a preferred example of the robot control method, robot control apparatus, and program of the present invention will be described with reference to the accompanying drawings.
(Embodiment)

  FIG. 1 is a perspective view showing a configuration example according to one form of work by a robot. FIG. 1 shows, as an example, a case where the robot 1 performs an operation of attaching a screw 21 or a screw 22 as a member to the workpiece 10. The robot 1 includes a linear arm portion 3, a joint portion 2 that is a fulcrum of the pivoting operation of the arm portion 3, and a support portion 7. The joint portion 2 and the arm portion are sequentially arranged from the support portion 7. It is the structure which three sets are extending | stretching considering 3 as one set. In addition, the robot 1 has a gripping part 5 made of three fingers for gripping a member at the tip of the arm part 3 farthest from the support part 7. That is, the robot 1 is a so-called multi-joint robot that can be freely operated by the joint portion 2 and the arm portion 3. Further, the robot 1 is provided adjacent to the support unit 7 and controls a robot control device 4 for controlling the operation of the robot 1, and a camera (photographing device) disposed on the arm unit 3 provided with the grip unit 5. 6. The camera 6 is arranged so as to photograph the tip direction of the arm portion 3 to which the camera 6 is attached.

  A workpiece 10 on which the robot 1 operates is provided with a mounting portion 11 to which a member is attached and a marker 15 having a two-dimensional code indicating the type information of the member. In this case, the workpiece 10 is conveyed by the belt conveyor 12. It has become. Further, the screws 21 and 22 as members are arranged in the supply units A and B in a state of being aligned by a parts feeder (not shown). The workpiece 10 and the supply units A and B are arranged within a range where the robot 1 can work.

  Here, the marker 15 will be described. The marker 15 is a two-dimensional code printed in the vicinity of the attachment portion 11 of the workpiece 10, and the two-dimensional code describes type information of the screws 21 and 22 that are members. The robot 1 can acquire the type information by photographing the marker 15 with the camera 6, and performs work based on the type information. A series of these operations will be described later with reference to FIG. The two-dimensional code of the marker 15 is a code having information in the two-dimensional direction of the horizontal direction and the vertical direction. For example, when compared with a barcode or the like which is a one-dimensional code, a large amount of information is obtained in a small area. It is possible to have a quantity. The two-dimensional code can handle kanji, kana, alphabetic characters, numbers, binary data, and the like.

  In general, the member type information by the marker 15 is, for example, that the member is the screw 21 of the two types of the screw 21 in the supply unit A and the screw 22 in the supply unit B. It is information to show. In this case, the robot 1 that has acquired that the screw 21 is a member as the type information from the marker 15 acquires data on the mounting method such as the mounting position, direction, and torque corresponding to the screw 21 from the database unit or the like. The work of attaching the screw 21 to the workpiece 10 is performed. In contrast to this method, in the present embodiment, as the member type information, in addition to the member being the screw 21, the attachment position in which the screw 21 is attached to the attachment portion 11 formed on the upper surface of the workpiece 10. The data shown, the data indicating the mounting direction that the mounting portion 11 is a screw hole perpendicular to the upper surface, and the mounting that the screw 21 is rotated to the right and tightened, for example, with a torque of 5 N · m Includes method data. Therefore, the robot control device 4 of the robot 1 does not need to hold almost any type information regarding members, and can suppress the amount of information stored in the database unit to a minimum.

  Next, the configuration of the robot control device 4 that controls the operation of the robot 1 will be described. FIG. 2 is a block diagram showing the configuration of the robot control device. Strictly speaking, the robot 1 shown in FIG. 2 indicates the joint portion 2, the arm portion 3, and the grip portion 5 that are involved in driving the robot. Referring to FIG. 2, the robot control device 4 includes a camera control unit 41 that controls the camera 6 in order to acquire an image of the workpiece 10, and marker information analysis that analyzes the image and acquires member type information. The part 42, the robot drive control part 43 for controlling the attachment work of the member to the work 10 by the robot 1, and the work other than the marker compliant work performed based on the information of the marker 15, that is, the work 10 has no marker 15 And a database unit 44 having data and the like related to non-compliant work performed in some cases. The robot control device 4 captures and captures a ROM (Read Only Memory) 47 in which a program for controlling the robot 1 by referring to the robot drive control unit 43 and the workpiece 10 photographed by the camera 6 are captured. Random Access Memory (RAM) 46 that temporarily stores the type information acquired from the markers 15 included in the camera, and the camera control unit 41 and marker information based on information such as programs stored in the ROM 47 and the RAM 46 And a CPU (Central Processing Unit) 45 that executes control of the analysis unit 42 and the robot drive control unit 43.

  A specific procedure of the tightening operation for attaching either the screw 21 or the screw 22 to the workpiece 10 in the configuration including the robot 1, the screws 21, 22 and the workpiece 10 as described above will be described. This tightening operation corresponds to the marker-compliant operation described above, and is performed based on the information of the marker 15. FIG. 3 is a flowchart showing a procedure of work by the robot. 4A is a perspective view showing a state of photographing by the camera, FIG. 4B is a perspective view showing a state of gripping the screw, and FIG. 4C is a perspective view showing a state of attaching the screw. It is. The flowchart shown in FIG. 3 shows the steps of the tightening operation performed by the joint unit 2, arm unit 3, gripping unit 5, and camera 6 of the robot 1 based on the control of the robot control device 4. FIG. 4 shows the operation of the robot 1 in the main steps of the flowchart.

  First, in step S1, the robot moves to the vicinity of the workpiece 10. Specifically, the robot drive control unit 43 of the robot control device 4 refers to data corresponding to the tightening operation from the database unit 44 to roughly grasp the position of the workpiece 10 and is attached to the arm unit 3. The camera 6 is moved to the vicinity of the workpiece 10. As shown in FIG. 4A, the moved camera 6 faces the workpiece 10 and is positioned so as to face the attachment portion 11 of the workpiece 10. That is, the camera 6 has moved to a preferred position where an image including the marker 15 printed in the vicinity of the attachment portion 11 can be obtained. This step S1 corresponds to a moving step. Then, after determining that the CPU 45 has moved to the vicinity of the workpiece 10, the process proceeds to step S2.

  In step S2, camera shooting is performed. This photographing is performed by controlling the camera 6 by the camera control unit 41 for almost the entire workpiece 10. According to the camera 6, as shown in FIG. 4A, the camera 6 is positioned in the direction of the workpiece 10, and it is possible to reliably obtain an image of the workpiece 10 including the marker 15. The image captured by the camera 6 is stored in the RAM 46. This step S2 corresponds to a photographing step. And after memorize | storing the imaged image | photographed, it progresses to step S3.

  In step S3, it is determined whether or not the marker 15 has been recognized. This is performed by the CPU 45 analyzing the imaging stored in the RAM 46 and determining whether or not the marker 15 to be printed on the workpiece 10 has been detected. This step S3 corresponds to a detection step. If the marker 15 is detected, the process proceeds to step S4. On the other hand, if the marker 15 is not detected, the process proceeds to step S5.

  When the marker 15 is detected, information on the marker 15 is acquired in step S4. This is performed by the marker information analysis unit 42 recognizing and acquiring a two-dimensional code having member type information from the marker 15 included in the imaging stored in the RAM 46. After acquiring the information of the marker 15, the process proceeds to step S6.

  On the other hand, if the marker 15 is not detected, it is determined in step S5 whether or not information relating to the member can be acquired from the database unit 44. In this case, since the marker 15 is not detected, the CPU 45 determines that the non-compliant work is to be performed, and acquires from the database unit 44 information on the non-compliant work that has been instructed in advance to be performed without the marker 15. . In this case, the non-compliant work is a work other than the tightening work for attaching either the screw 21 or the screw 22 to the workpiece 10. That is, the robot 1 attaches a member different from the screws 21 and 22 to an attachment portion that does not have the marker 15 in the vicinity. For example, even when non-compliant work is continuously performed, even if the marker-compliant work is performed on a specific attachment portion 11, the marker 15 is printed in the vicinity of the attachment portion 11. The robot 1 can be instructed that the work content is different from the non-compliant work. That is, the robot 1 can perform work based on the type information of the marker 15 without changing the program of the robot control device 4. If non-compliant work information can be acquired, the process proceeds to step S7. On the other hand, if non-compliant work information cannot be obtained, the flow ends.

  If the information about the marker 15 can be acquired at step S4, the type information is acquired based on the information about the marker 15 at step S6. The type information is acquired by the marker information analysis unit 42 analyzing the two-dimensional code of the marker 15. Although this type information has already been described, the main information is that the member to be attached to the workpiece 10 is the screw 21. Furthermore, the screw 21 is attached to the attachment portion 11 of the workpiece 10, and the screw 21 is set in the vertical direction. Information on attachment, such as inserting and rotating the screw 21 in the right direction and tightening with a torque of 5 N · m, for example, is also included. The type information acquired by the marker information analysis unit 42 is stored in the RAM 46. Steps S6 and S4 correspond to analysis steps. After all the type information is acquired and stored, the process proceeds to step S7.

  In step S7, the member is gripped. This is performed by the robot drive control unit 43 recognizing the screw 21 as a member based on the type information of the marker 15 and gripping the screw 21. In this case, the screw 21 is aligned with the supply unit A, and the robot drive control unit 43 controls the joint unit 2 and the arm unit 3 to move the grip unit 5 to the supply unit A. With a finger, the screw 21 is grasped and extracted from the supply unit A. FIG. 4B shows a state in step S <b> 7 in which the grip portion 5 has extracted the screw 21 from the supply portion A. After gripping the screw 21, the process proceeds to step S8.

  In step S <b> 8, the workpiece 10 moves to the attachment portion 11. This is performed by the robot drive control unit 43 controlling the joint unit 2 and the arm unit 3 and carrying the screw 21 to the position of the mounting unit 11 while the grip unit 5 is gripping the screw 21. In this case, the work 10 has one mounting portion 11, and the position information of the mounting portion 11 for moving the screw 21 to the mounting portion 11 is acquired from the type information by the marker information analysis unit 42. After the movement is completed, the process proceeds to step S9.

  In step S9, the member is attached to the attachment portion 11. This is performed by the robot drive control unit 43 controlling the grip unit 5, the joint unit 2, and the arm unit 3 to insert the screw 21 into the mounting unit 11 while rotating the screw 21 clockwise. It is. In this case, the gripping part 5 fastens the screw 21 to the mounting part 11 with a torque of 5 N · m. Data relating to these attachment methods is acquired from the type information by the marker information analysis unit 42. FIG. 4C shows a state in step S <b> 9 in which the screw 21 is attached to the attachment portion 11 of the workpiece 10. Step S9, step S7 and step S8 correspond to work steps. The flow ends through the above steps.

  As a main effect of the robot control method in the embodiment described above, information for the robot 1 to work is acquired from the marker 15 of the workpiece 10 as type information. The amount of information that must be reduced can be mentioned. Furthermore, when it is desired to change the work by the robot 1, it can be easily performed by changing the marker 15, and there is no need to change the program of the robot control device 4. This is because the robot control method passes through the movement step, the imaging step, the detection step, and the analysis step, and information indicating what the member is from the marker 15 printed on the workpiece 10 to which the member is attached, and the workpiece 10 of the member. This is because the type information including the attachment method is acquired. Based on this type information, the robot 1 can reliably perform the work of attaching the screw 21 as a member to the work 10 in the work step.

  In addition, the robot control method, the robot control device, and the program are not limited to the above-described embodiment, and the same effects as those of the embodiment can be obtained even in the following modifications.

  (Modification 1) In the robot control method, the member type information is obtained by analyzing the two-dimensional code of the marker 15, but is not limited to this method. For example, a method using other means such as a barcode may be used instead of the two-dimensional code. Alternatively, the marker 15 may be set only to designate data to be referred to in the database unit 44. Although the load on the database unit 44 is enormous compared to the present embodiment, the robot 1 can work based on the data.

  (Modification 2) The marker 15 is printed on the workpiece 10, but the marker 15 is not printed on the workpiece 10, but is in a label shape and is attached to the workpiece 10. good. According to this, a measure for changing or updating the type information can be performed more quickly than in the case of printing.

  (Modification 3) The camera 6 is not limited to the structure provided in the arm part 3 of the robot 1, and may be a method in which the gripping part 5 is carried from another place to take a picture when necessary. However, the camera 6 is preferably under the control of the robot control device 4.

  (Modification 4) The robot 1 is configured to have three sets of the joint portion 2 and the arm portion 3 as one set, but may have a configuration other than the three sets. For example, the robot 1 may be a robot having a plurality of arms such as an articulated robot having a so-called 6-axis or 7-axis configuration, a double-arm robot, or the like. In other words, the robot control method can be effectively applied to robots configured in various mechanism forms in order to perform operations related to various operations. The screws 21 and 22 are arranged in alignment with the supply units A and B, but the robot 1 can select the direction of the screws 21 and 22 from among the members randomly stored in a box or the like. It is possible to use a method of judging the above and holding in the same posture. Furthermore, the workpiece 10 is not limited to the configuration of being conveyed by the belt conveyor 12.

  (Modification 5) Although the grip part 5 of the robot 1 is composed of three fingers, it is not limited to this. The grip part 5 may have a number of fingers other than three, for example, a flexible and versatile five-finger grip part structure close to a human hand, or a gripper specialized for gripping a specific member. A simple gripper configuration or the like may be used. Further, the grip portion 5 may be configured to adsorb the member by evacuation or magnetic force for simple movement of the member.

  (Modification 6) The robot controller 4 may have a configuration in which the database unit 44 as an external device is connected only when necessary without incorporating the database unit 44.

  (Modification 7) In the flowchart of FIG. 3, in steps S4 and S6 that are analysis steps, the type information includes that the member attached to the workpiece 10 is the screw 21 and details of the method of attaching the screw 21. However, the present invention is not limited to this acquisition method. For example, in the analysis step, only that the member is the screw 21 is acquired as type information, and details of the mounting method of the screw 21 are acquired from the database unit 44. The method of doing etc. may be used. According to this, even a barcode with a small amount of information can be sufficiently utilized as the marker 15.

  (Modification 8) In the flowchart of FIG. 3, if step S5 is deleted and the marker 15 cannot be recognized in step S3, the flow may be terminated. That is, all the actual work performed by the robot 1 on the workpiece 10 is performed based on the type information from the marker 15.

  (Modification 9) In the embodiment, a simple example in which the robot 1 performs the work of attaching the screw 21 to one attachment portion 11 based on the type information of the marker 15 has been described. The robot control method can sufficiently cope with complicated work such as attaching a robot.

  DESCRIPTION OF SYMBOLS 1 ... Robot, 2 ... Joint part, 3 ... Arm part, 4 ... Robot control apparatus, 5 ... Grasping part, 6 ... Camera as imaging | photography apparatus, 10 ... Work, 11 ... Mounting part, 15 ... Marker, 21 ... Screw, 22 ... Screws, 41 ... Camera control unit, 42 ... Marker information analysis unit, 43 ... Robot drive control unit, 47 ... ROM (for program storage).

Claims (5)

A robot control method for controlling a robot and attaching a member to a workpiece,
A moving step of moving the photographing device to the position of the workpiece;
An imaging step of acquiring an image of the workpiece imaged by the imaging device;
A detection step of detecting a marker of the workpiece from the imaging;
An analysis step of analyzing the marker and obtaining type information of the member;
And a work step of performing a work of attaching the member to the work based on the type information. The robot control method according to claim 1,
In the analyzing step, the type information including information relating to the attachment method of the member is acquired from the marker. The robot control method according to claim 1 or 2,
The robot control method according to claim 1, wherein the marker has a two-dimensional code that is disposed in the vicinity of an attachment portion to which the member is attached to the workpiece and includes the type information. A robot control device for controlling a robot and attaching a member to a workpiece,
A moving unit that moves the photographing device to the position of the workpiece;
A photographing unit that obtains an image of the workpiece photographed by the photographing device;
A detection unit for detecting a marker of the workpiece from the imaging;
An analysis unit for analyzing the marker and obtaining the type information of the member;
And a working unit for performing work for attaching the member to the workpiece based on the type information. A program for executing control for attaching a member to a workpiece by a robot,
A moving step of moving the photographing device to the position of the workpiece;
An imaging step of acquiring an image of the workpiece imaged by the imaging device;
A detection step of detecting a marker of the workpiece from the imaging;
An analysis step of analyzing the marker and obtaining type information of the member;
A program for causing the robot to execute an operation step of performing an operation of attaching the member to the workpiece based on the type information.

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