JP2010125583A - Robot arm device, and control method and control program of the robot arm device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve such problems that securing time for image processing is necessary to calculate the position of a product and a component in an image photographed by a camera, and if it takes long time to process the image, the conveyance speed of a conveying belt is decreased. <P>SOLUTION: The robot arm device operates in a working area A2 on the conveying belt 30 sequentially conveying a conveyed article 43. The robot arm device includes: the camera attached to the robot arm and photographing the image of the conveyed article 43 placed in a first position at an upstream side of the working area A2 on the conveying belt 30; a first position calculation part calculating the first position from the image; and a second position calculation part calculating a second position in which the conveyed article 43 is conveyed to the working area A2 based on the first position and a distance X2 in which the conveyed article 43 is conveyed from the first position to the working area A2. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a robot arm device, a control method for a robot arm device, and a control program.

  When the product or part is transported into the work area of the robot arm device, the robot arm device takes an image of the product or part with a camera attached to the tip of the robot arm, and uses the captured image to position the product or part. Is detected. Then, the tool or manipulator attached to the tip of the robot arm is moved to the position of the detected product or part to perform processing, assembly, inspection, and the like. For example, Patent Document 1 proposes a method in which a visual sensor is attached to a robot and a work is taken out according to the work loading state measured by the visual sensor.

JP 2003-34430 A

  However, it is necessary to secure time for image processing performed to calculate the position of the product or part in the image captured by the camera. For this reason, for example, when a plurality of products and parts are transported side by side on the transport belt, the products and parts are placed in the work area of the robot arm device while ensuring the processing time of the images of the products and parts. Supply. Accordingly, when the image processing time is long, there is a problem that the conveyance speed of the conveyance belt is slowed down.

  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 forms or application examples.

  Application Example 1 A robot arm device that performs work in a work area on the transport belt where a transported object is sequentially transported by a transport belt, the robot arm apparatus being attached to the robot arm and upstream of the work area A camera that captures an image of a transported object at a first position above; a first position calculating unit that calculates the first position from the image; the first position; A second position calculation unit that calculates a second position at which the conveyed object is conveyed to the work area based on a distance conveyed from one position to the work area. Robot arm device.

  According to this configuration, the camera is provided that captures an image of the transported object at the first position on the transport belt on the upstream side of the work area, and the first position calculation unit is configured to extract the first image from the image captured by the camera. The position of 1 is calculated. As a result, the first position is calculated by performing image processing at the time when the conveyed product is conveyed from the first position toward the work area, and the calculated first position and the conveyed item are the first position. The second position is calculated based on the distance from the position to the work area. Therefore, it is possible to suppress a decrease in the conveyance speed of the conveyance belt according to the time until the image processing is completed.

  Application Example 2 The robot described above, further comprising: a blur amount detection unit that detects the blur amount of the image; and a blur correction unit that corrects the blur of the image based on the blur amount. Arm device.

  According to this configuration, even if the image captured at the first position is blurred, it is possible to obtain an image in which the blur is suppressed by performing the blur correction. As a result, erroneous detection of the first position due to image blur can be suppressed.

  Application Example 3 After the transported object is transported based on the amount of blur detected from the image of the transported object initially transported to the first position, the transported object at the first position is imaged. The robot arm device described above, wherein the image is corrected.

  According to this configuration, it is not necessary to secure time for calculating the blur amount for correcting the blur of the image every time the transported object is sequentially transported on the transport belt. Therefore, it can suppress that the conveyance speed of a conveyance belt becomes slow.

  Application Example 4 In a robot arm apparatus that performs work in a work area in which conveyed objects are sequentially conveyed by a conveyance belt, the conveyance upstream of the work area on the conveyance belt is performed by a camera attached to the robot arm. A step of capturing an image of a conveyed product at a first position on the belt; a first position calculating step of calculating the first position from the image; the first position; And a second position calculating step of calculating a second position at which the conveyed product is transported to the work area based on a distance transported from the first position to the work area. A control method for the robot arm device.

  Application Example 5 In a robot arm apparatus that performs work in a work area in which a conveyed product is sequentially conveyed by a conveyance belt, the conveyance upstream of the work area on the conveyance belt is performed by a camera attached to the robot arm. A function for capturing an image of a conveyed product at a first position on the belt; a first position calculating function for calculating the first position from the image; the first position; Causing the computer to realize a second position calculation function for calculating a second position at which the conveyed product is transported to the work area based on a distance transported from the first position to the work area. A control program for a robot arm device.

Hereinafter, specific embodiments will be described with reference to the drawings.
(First embodiment)
FIG. 1 is an external perspective view of the robot arm device 100. The upper pedestal 13 in the robot arm device 100 is provided on the lower pedestal 15 and is rotated by driving a motor (not shown) at the rotation position 14. The robot arm 10 is provided on the upper pedestal 13 and is rotated by driving a motor 12 at a rotation position 11.

  The robot arm 7 is connected to the robot arm 10 and is rotated by driving a motor 9 at a rotational position 8. The robot arm 5 is connected to the robot arm 7 and rotated at a rotational position 6 by driving a motor (not shown).

  The robot arm 4 is provided in the robot arm 5 and is rotated about a rotation axis A by a motor (not shown). The robot arm 2 is connected to the robot arm 4 and is rotated at a rotational position 3 by driving a motor (not shown).

  A manipulator 1 is attached to the tip of the robot arm 2. A manipulator can be selected and attached to the tip of the robot arm 2 in accordance with the shape of a part or product in a production line, an assembly method, a processing method, or the like.

  A support member 21 is attached to the robot arm 4, and a camera 20 is attached to the support member 21. The camera 20 captures an image for calculating the position of a conveyed product (not shown) or part (not shown).

  The control box 18 is connected to the main body of the robot arm device 100 by the power cable 16 and the control cable 17. The control box 18 incorporates a power supply circuit (not shown), a motor drive circuit unit (not shown) for driving the motor described above, and a controller (not shown). The controller controls the motor drive circuit unit and calculates the position of products and parts from the image captured by the camera 20.

  FIG. 2 is a diagram for explaining a state in which the robot arm device 100 moves the conveyed product. FIG. 2 shows a conveyance belt 30 that conveys the conveyed items 40 to 43 in the conveyance direction D1, and a conveyance belt 60 that conveys the pallets 61 to 63 in the conveyance direction D2. The conveyor belt 30 and the conveyor belt 60 are each driven by a motor (not shown). In the transported articles 40 to 43 transported by the transport belt 30, the adjacent distances L1 in the transport direction D1 are different from each other.

  The support portions 31 and 32 that support the conveyor belt 30 are fixed to a floor surface (not shown) on which the lower base 15 of the robot arm device 100 is placed. The support unit 32 includes a conveyance speed detection unit 71 that detects the conveyance speed of the conveyance belt 30. The conveyance speed detected by the conveyance speed detection unit 71 is output to the control box 18 of the robot arm device 100 via the signal cable 72.

  A stripe 70 indicated by a thick solid line is formed on the transport belt 30 so as to extend in the transport direction D1. The stripe 70 includes a plurality of straight lines extending in a direction perpendicular to the transport direction D1. The adjacent distance between the straight lines in the transport direction D1 forming the stripe 70 is constant. The conveyance speed detector 71 includes a timer (not shown) that measures time.

  When the plurality of straight lines in the stripe 70 pass through the conveyance speed detection unit 71 due to the rotation of the conveyance belt 30, the conveyance speed detection unit 71 optically detects and detects the number of straight lines by a phototransistor (not shown). Based on the number and the adjacent distance between the straight lines and the time, the surface of the conveyor belt 30 on which the articles 40 to 43 are placed detects the conveyance speed that moves in the conveyance direction D1.

  A region indicated by A <b> 2 indicates a work region in which the manipulator 1 attached to the robot arm device 100 performs work on the transport belt 30. In the work area A2, the robot arm device 100 grips the transported object 40 placed on the transport belt 30 by the manipulator 1 in FIG. 1, and stops the transported object 40 from the work area A2 at the position shown in FIG. It is moved to the hole 64 of the pallet 62.

  While the robot arm device 100 moves the conveyed items sequentially transferred from the upstream side to the work area A2 to the pallet 62, the rotation of the conveying belt 60 is stopped. When the conveyed product is placed in all the holes 64 formed in the pallet 62, the conveying belt 60 rotates again to move the pallets 61 to 63 in the conveying direction D2. 2 is moved to the position of the pallet 62 in FIG. 2, and the pallets 62 having the conveyed objects placed in all the holes 64 are moved to the positions of the pallets 63. Is done.

  G surrounded by a broken line is an image field viewed from the camera 20 attached to the robot arm 2 through the support member 21. When the transported object 43 is in the imaging area A1 on the transport belt 30, the direction of the robot arm 2 is set in the path when the manipulator 1 in FIG. 1 moves between the work area A2 and the pallet 62, and the camera The image of the image field G including the conveyed product 43 is picked up by 20.

  Marks 33 and 34 are formed on the support portion 31, and marks 35 and 36 are formed on the support portion 32. When an image is picked up in the image field of view G, the conveyed product 43 is at a position shown in the imaging region A1 that is a range from the position of the marks 34 and 35 shown in P0 to the position of the marks 33 and 36 shown in P1.

  FIG. 3 is a diagram illustrating an electrical block configuration of the robot arm device 100 according to the present embodiment. The controller 54 provided in the control box 18 of FIG. 1 includes a CPU 50, a ROM 51, a RAM 52, and an interface (I / F) 53. The CPU 50 reads the control program stored in the ROM 51 into the RAM 52 and executes it.

  A motor drive circuit unit 56 provided in the control box 18 performs drive control of the motor 57 based on a control signal output from the CPU 50 via the I / F 53. The motor 57 is a motor (not shown) for rotating the motors 9 and 12, the upper pedestal 13, and the robot arms 2, 4, and 5 for rotating the robot arms 7 and 10 of the robot arm device 100 of FIG. including.

  The time measuring unit 55 having a time measuring function is provided in the control box 18 and outputs time information to the CPU 50 via the I / F 53.

  The conveyance speed detection unit 71 (see FIG. 2) detects the conveyance speed at which the conveyance belt 30 conveys the conveyance objects 40 to 43, and outputs it to the CPU 50 via the I / F 53.

  FIG. 4 is a diagram for explaining a method of calculating the position of a conveyed product conveyed to the work area A2 using an image captured on the upstream side of the work area A2. The camera 20 captures the conveyed product 43 conveyed at the first position, which is the upstream position of the work area A2, with the image field of view G at the first time t1.

  The first position calculation unit 58 in FIG. 3 calculates the first position of the conveyed product 43 at the first time t1 from the image captured in the image visual field G. In the present embodiment, the first position is calculated as a distance X1 in the transport direction D1 and a distance Y1 in a direction orthogonal to the transport direction D1, with reference to the marks 34 and 35 in FIG.

  Next, a method in which the second position calculation unit 59 in FIG. 3 calculates the second position of the transported object 43 at the second time t2 transported to the work area A2 in FIG. 4 will be described.

  The distance L2 in the transport direction D1 in FIG. 4 indicates the distance from the position of the most downstream position P1 in the imaging area A1 to the position of the most upstream position P2 in the work area A2. The distance L2 is the shortest distance between the imaging area A1 and the work area A2. Therefore, the shortest time that the conveyed product 43 in the imaging area A1 is conveyed from the imaging area A1 to the work area A2 is calculated from the distance L2 and the conveying speed of the conveying belt 30.

  A distance L3 in the transport direction D1 indicates a distance from the position of the most upstream position P0 in the imaging area A1 to the position of the most downstream position P3 in the work area A2. The distance L3 is the longest distance between the imaging area A1 and the work area A2. Therefore, the longest time that the conveyed product 43 in the imaging area A1 is conveyed from the imaging area A1 to the work area A2 is calculated from the distance L3 and the conveying speed of the conveying belt 30.

  Therefore, in this embodiment, an intermediate time between the shortest time and the longest time calculated above is calculated as the second time t2.

  The second position calculation unit 59 in FIG. 3 calculates the second position at the calculated second time t2. As shown in FIG. 4, the second position is a distance L4 from the reference position indicated by P0 in the transport direction D1.

  The distance L4 is calculated by adding the distance X2 calculated by the first position calculator 58 to the distance X1 at the first time t1 and the transported object 43 being transported from the first time t1 to the second time t2. It is calculated by doing.

  The distance X2 is calculated by multiplying the conveyance speed detected by the conveyance speed detection unit 71 by the time from the first time t1 to the second time t2.

  Since the conveyed product 43 is conveyed as it is from the first time t1 to the second time t2 without changing the position on the conveying belt 30, the position in the direction orthogonal to the conveying direction D1 at the second time t2 is The position is the same as the position indicated by the distance Y1 at the first time t1.

  The first position calculation unit 58 and the second position calculation unit 59 are composed of programs, and function when the CPU 50 reads out the programs stored in the ROM 51 to the RAM 52 and executes them.

  FIG. 5 is a flowchart of a process for calculating the second position of the conveyed product 43 at the second time t2. A processing method for calculating the second position will be described with reference to FIGS. 4 and 5.

  In step S200, the CPU 50 images the transported object 43 located on the upstream side of the work area A2 at the first time t1 with the image field G including the imaging area A1.

  In step S210, the first position calculation unit 58 performs image processing based on the image captured in step S200, and calculates the distance X1 from the origin indicated by P0 in the transport direction D1 as the first position of the transported object 43. To do. In step S <b> 220, the second position calculation unit 59 acquires the conveyance speed of the conveyance belt 30 from the conveyance speed detection unit 71.

  In step S230, the second position calculation unit 59 calculates the product of the time from the first time t1 to the second time t2 and the transport speed of the transport belt 30, thereby starting from the first time t1. A distance X2 up to the second time t2 is calculated.

  In step S240, the distance X1 calculated in step S210 and the distance X2 calculated in step S230 are added to calculate a distance L4 from the origin indicated by P0 at the second time t2.

  The conveyance speed detection unit 71 of this embodiment is a method of optically detecting the stripe 70, but includes a roller (not shown) that contacts the conveyance belt 30, and the conveyance belt 30 is based on the number of rotations of the roller. Alternatively, a method for detecting the transport speed may be used.

  In addition, the transport speed detection unit 71 of the present embodiment outputs the transport speed based on the time from the time measuring unit 55 provided in the transport speed detection unit 71, but acquires the movement amount of the stripe 70, and the robot arm device The CPU 50 of the robot arm apparatus 100 may calculate the conveyance speed based on the time from the time measuring unit 55 provided in the 100.

  In the present embodiment, the second time t2 is such that the transport speed of the transport belt 30 is constant, and the intermediate time between the shortest time and the longest time from the imaging area A1 to the work area A2 is the second time t2. In the case where the conveyance belt 30 repeats conveyance and stop, the predetermined time for which the conveyance object 43 is predicted to be in the range of the work area A2 is set from the control method for conveying the conveyance belt 30. You may make it do.

  As described above, the robot arm device 100 described in the present embodiment is a robot arm device 100 that performs work in the work area A2 in which transported objects are sequentially transported by the transport belt 30, and is attached to the robot arm 2 and is transported by the transport belt. The camera 20 that captures an image of the transported object 43 that transports a first position located upstream of the work area A2 on the 30 and a first position that calculates the first position of the transported object 43 from the captured image. Transported to the work area A2 based on the position calculation unit 58, the distance X1 from the origin indicated by P0 as the first position, and the distance X2 that the transported object 43 is transported from the first position. A second position calculation unit 59 that calculates a distance L4 from the reference position indicated by P0 as the second position of the object 43 (see FIG. 4).

  According to this configuration, the camera 20 that captures an image of the transported object 43 at the first position on the transport belt 30 on the upstream side of the work area A2 is provided, and the first position calculation unit 58 is controlled by the camera 20. A first position is calculated from the captured image. As a result, the first position is calculated by performing image processing at the time when the conveyed product 43 is being conveyed from the first position toward the work area A2, and the second position is calculated based on the calculated first position. Calculate the position. Therefore, it is possible to suppress a decrease in the conveyance speed of the conveyance belt 30 according to the time until the image processing is completed.

(Second embodiment)
In the second embodiment, a robot arm apparatus including a shake correction unit that corrects image blur will be described. FIG. 6 is an external perspective view of the robot arm device 100a in the present embodiment.

  In the robot arm device 100a, the support member 21 of the robot arm device 100 described in the first embodiment is provided with a gyro sensor 22 that detects a rotational angular velocity.

  FIG. 7 is a block diagram showing an electrical configuration in the present embodiment. FIG. 7 is a block diagram showing the electrical configuration of FIG. 3 described in the first embodiment, and includes a gyro sensor 22 and a shake correction unit 80 that corrects a shake of an image.

  The shake correction unit 80 calculates the shake amount in units of pixels in the horizontal direction and the vertical direction according to the rotational angular velocity detected by the gyro sensor 22. The blur correction unit 80 corrects the blur of the image captured in the image field G shown in FIGS. 2 and 4 based on the calculated blur amount.

  FIG. 8 is a flowchart of a process for calculating the second position at which the conveyed product 43 is conveyed to the work area A2 in the present embodiment. FIG. 8 is obtained by adding step S202, step S206, and step S208 to the flowchart of FIG. 5 described in the first embodiment.

  In step S <b> 202, the rotational angular velocity generated when the camera 20 captures an image of the image field G is acquired from the gyro sensor 22. In step S206, the shake correction unit 80 calculates a shake amount in units of pixels in the horizontal direction and the vertical direction according to the acquired rotation angular velocity.

  In step S208, the blur correction unit 80 corrects the image captured in step S200 based on the blur amount calculated in step S206.

  According to this configuration, it is possible to prevent the first position calculation unit 58 from erroneously detecting the first position when the image captured in the image field G is blurred.

  The shake correction unit 80 according to the present embodiment corrects the shake of the image captured in the image field G, but the camera 20 includes an actuator (not shown) that moves the optical axis of a lens (not shown). When taking an image in the image field G, the optical axis of the lens may be corrected according to the rotational angular velocity detected by the gyro sensor 22.

  Alternatively, the camera 20 is provided with an actuator (not shown) that moves an image pickup device (not shown) such as a CCD, and the camera 20 picks up an image in the image field of view G according to the rotational angular velocity detected by the gyro sensor 22. The image sensor may be corrected.

(Third embodiment)
In the third embodiment, using the deviation amount used when correcting the blur of the image of the transported object first transported to the imaging area A1, the images of the transported object sequentially transported to the imaging area A1 thereafter. A case where the correction is performed will be described.

  The robot arm 2 repeatedly moves on the same path while holding a transported object having the same shape and the same weight by the manipulator 1. The camera 20 attached to the robot arm 2 sequentially captures an image of the image field of view G at the same position as the image of the conveyed object that is conveyed to the imaging area A1. Therefore, the rotational angular velocities detected by the gyro sensor 22 when the camera 20 captures an image are substantially the same.

  Therefore, in this embodiment, the shift amount used when correcting the blur of the image of the transported object first transported to the imaging area A1 is used, and thereafter the transported objects sequentially transported to the imaging area A1 are sequentially used. Correct the image.

  FIG. 9 is a flowchart of a process for calculating a second position at which the conveyed product 43 is conveyed to the work area A2 in the present embodiment. FIG. 9 is obtained by adding steps S201, S204, and S207 to the flowchart of FIG. 8 described in the second embodiment.

  In step S201, it is determined whether the conveyed product conveyed to the imaging area A1 in FIG. 4 is the one conveyed first. If it is the first transported item (Yes), the process proceeds to step S202. If it is not the first transported item (No), the process proceeds to step S204.

  In step S202, the rotational angular velocity is acquired from the gyro sensor 22. In step S206, the amount of blurring in units of pixels corresponding to the detected rotational angular velocity is calculated. In step S207, the calculated shake amount is stored in the RAM 52.

  In step S204, the amount of shake for correction is acquired from the RAM 52, and the process proceeds to step S208.

  By doing so, the rotational angular velocity is detected each time the conveyed object is sequentially conveyed on the conveying belt 30, and the time for calculating the blur amount in units of pixels corresponding to the detected rotational angular velocity is not secured. Good. Therefore, it can suppress that the conveyance speed of a conveyance belt becomes slow.

The external appearance perspective view of a robot arm apparatus. The figure explaining a mode when a robot arm apparatus moves a conveyed product. The figure which shows the electrical block structure of the robot arm apparatus in 1st Example. The figure explaining the method of calculating the position of the conveyed product conveyed to a work area using the image imaged in the upstream of the work area. The flowchart of the process which calculates the 2nd position of the conveyed product in 2nd time. The external appearance perspective view of the robot arm apparatus in 2nd Example. The block diagram which shows the electrical structure in 2nd Example. The flowchart of the process which calculates the 2nd position where the conveyed product in 2nd Example is conveyed to a work area. The flowchart of the process which calculates the 2nd position where the conveyed product in 3rd Example is conveyed to a work area.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 2 ... Robot arm, 20 ... Camera, 30 ... Conveyor belt, 40-43 ... Conveyed object, 58 ... 1st position calculation part, 59 ... 2nd position calculation part, 80 ... Shake correction part, 100, 100a ... Robot Arm device, A2 ... work area.

Claims (5)

A robot arm device that performs work in a work area on the transport belt where transported materials are sequentially transported by a transport belt,
A camera attached to a robot arm and capturing an image of a transported object at a first position on the transport belt upstream of the work area;
A first position calculation unit for calculating the first position from the image;
Based on the first position and a distance by which the conveyed product is conveyed from the first position to the work area, a second position for calculating a second position at which the conveyed object is conveyed to the work area is calculated. A position calculating unit. The robot arm device according to claim 1,
Furthermore, a shake amount detection unit for detecting the shake amount of the image,
A robot arm device, comprising: a shake correction unit that corrects a shake of the image based on the shake amount. The robot arm device according to claim 2,
Based on the amount of blur detected from the image of the conveyed object first conveyed to the first position, the image obtained by imaging the conveyed object at the first position is corrected after the conveyed object is conveyed. A robot arm device characterized by that. A robot arm device that performs work in a work area in which transported materials are sequentially transported by a transport belt,
Capturing an image of a transported object at a first position on the transport belt upstream of the work area on the transport belt by a camera attached to a robot arm;
A first position calculating step of calculating the first position from the image;
Based on the first position and a distance by which the conveyed product is conveyed from the first position to the work area, a second position for calculating a second position at which the conveyed object is conveyed to the work area is calculated. And a position calculating step of the robot arm apparatus. A robot arm device that performs work in a work area in which transported materials are sequentially transported by a transport belt,
A function of capturing an image of a transported object at a first position on the transport belt on the upstream side of the work area on the transport belt by a camera attached to a robot arm;
A first position calculating function for calculating the first position from the image;
Based on the first position and a distance by which the conveyed product is conveyed from the first position to the work area, a second position for calculating a second position at which the conveyed object is conveyed to the work area is calculated. A control program for a robot arm apparatus, characterized by causing a computer to realize the position calculation function of

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