JP2017074631A - Manufacturing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing system applicable also to a production line such as a precise electronic component, and capable of expanding a work range of a robot working in the production line.SOLUTION: A manufacturing system 100 in which manufacturing work is conducted in a plurality of work spaces 102, 104 and 106, comprises: a robot arm 108; a movable body (an automatic guided vehicle 110) in which a robot arm is placed and which reciprocates in the plurality of work spaces; an imaging device (stereoscopic cameras 122 and 124) provided in the movable body; a position identification mark (calibration plates 118 and 120) which has a form capable of identifying a position by image recognition and at least one of which is installed in each of the plurality of work spaces; and a control device 126 for correcting a position of the movable body with respect to the work spaces by the image recognition of the position identification mark using the imaging device.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a manufacturing system used in a production line such as a factory.

  Conventionally, industrial robots and automatic guided vehicles have been used in production lines such as factories. Industrial robots are generally installed in place and perform manufacturing operations. The automatic guided vehicle travels and stops by recognizing a magnetic tape, a magnetic bar, or a shape on the floor, and conveys parts used in a production line. In recent years, further expansion of the work range is required for industrial robots. In addition, as an automated guided vehicle, a vehicle that can move in all directions is widespread.

  Patent Document 1 discloses a robot that is fixedly arranged by moving a transport carriage on which a work such as an instrument panel is placed in front, back, left, right, up and down during the operation of the robot. A technique for pseudo-expanding the work range is disclosed.

JP-A-8-174355

  However, it is difficult to apply the technique of Patent Document 1 to a production line for precise electronic parts and the like. First, when an electronic component is placed on a transport carriage and transported, there is a risk that the electronic component will be displaced on the transport carriage. For this reason, there is a risk that operations such as directly gripping an electronic component placed on the transport carriage with an industrial robot may be difficult.

  In addition, when tire slippage occurs due to the state of the tire of the transport carriage or the state of the floor surface and a positional shift occurs when the transport carriage is stopped, there is a possibility that the electronic component does not enter the drive range of the industrial robot. In particular, in a cart that can move in all directions, it is necessary to secure position accuracy for two axes, the x-axis (horizontal direction) and the y-axis (vertical direction). The required position accuracy cannot be obtained. Further, in a trolley that can move in all directions, if the trolley stops in a state where it is inclined with respect to the work space, the horizontality between the industrial robot and the electronic components may be lost, and assembly accuracy may be reduced.

  The present invention has been made in view of the above problems, and can be applied to a production line for precision electronic components and the like, and provides a manufacturing system capable of expanding the work range of a robot working on the production line. For the purpose.

  In order to solve the above-mentioned problems, the present inventors have intensively studied. As a result, if electronic parts are arranged in a work space and a robot arm is placed on a moving body, positional deviation of the electronic parts on the transport carriage occurs. First, we focused on the ability to expand the work range of the robot arm. Therefore, further investigation is made, and a position identification mark that can recognize an image is provided in each of the plurality of work spaces, and this is imaged by an imaging device provided on the moving body, and the position of the moving body is corrected to obtain position accuracy. As a result, the present invention has been completed.

  That is, according to one aspect of the present invention, the robot arm, the moving body on which the robot arm is mounted and reciprocating the plurality of work spaces, the imaging device provided in the moving body, and the position by image recognition The position of the movable body with respect to the work space is determined by image recognition of the position identification mark that is in an identifiable form and is installed in each of the plurality of work spaces, and the position identification mark using the imaging device. There is provided a manufacturing system comprising a control device for correction.

  According to the embodiment of the present invention, a manufacturing system that can be applied to a production line for precision electronic parts and the like and that can expand the working range of a robot that works on the production line is provided.

It is the schematic of the manufacturing system which is 1 aspect of embodiment of this invention. It is an arrow A figure of FIG. FIG. 3 is an explanatory diagram of a calibration plate as an example of the position identification mark of FIG. 2. It is a flowchart which illustrates the procedure of position shift correction | amendment of the trolley | bogie of FIG. It is explanatory drawing of the stopper provided in the bottom face of the trolley | bogie of FIG. FIG. 5 is a diagram illustrating the relationship between lateral deviation correction and vertical deviation correction in the positional deviation correction procedure of FIG. 4. FIG. 7 is an explanatory diagram when the lateral shift of FIG. 6 occurs. It is explanatory drawing when the vertical shift of FIG. 6 generate | occur | produces. It is a flowchart which illustrates the modification of FIG. It is a figure which shows the 1st modification of the manufacturing system of FIG. It is a figure which shows the 2nd modification of the manufacturing system of FIG.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same functions and configurations are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are illustrated. Omitted.

  FIG. 1 is a schematic diagram of a manufacturing system 100 that is an aspect of an embodiment of the present invention. As shown in FIG. 1, the manufacturing system 100 is used in a production line such as a factory. Specifically, in the manufacturing system 100, a robot arm 108 reciprocates between a plurality of work spaces 102, 104, and 106 on a work table 112, and a tray T (representatively) disposed in each work space 102, 104, 106 is represented. A manufacturing operation is carried out by gripping and assembling an electronic component P (represented by a reference symbol) from an electronic component P (represented by a reference symbol).

  FIG. 2 is an arrow A view of FIG. As shown in FIG. 2, the robot arm 108 is placed on a moving body that reciprocates in the work spaces 102, 104, and 106. Here, the movable body is an automatic guided vehicle (hereinafter simply referred to as “cart 110”) that is movable and rotatable in the horizontal direction (x-axis direction) and the vertical direction (y-axis direction) with respect to the work space.

  Since the carriage 110 is movable in all directions, there is a possibility that a positional deviation occurs in any direction when the carriage is stopped. In view of this, in the manufacturing system 100, at least one position identification mark having a form in which the position can be identified by image recognition is installed in each of the work spaces 102, 104, and 106 (see FIG. 1).

  FIG. 3 is an explanatory diagram of a calibration plate as an example of the position identification mark. In FIG. 2, reference numeral 118 is representative of one of the lower calibration plates, and reference numeral 120 is representative of one of the upper calibration plates. As illustrated in FIG. 3, the calibration plates 118 and 120 have values specific to the plate width L1, the dot size S and the pitch L2, and the arrangement relationship. The position identification mark is not limited to the calibration plates 118 and 120 but may be a so-called cross marker.

  Refer to FIG. 2 again. The carriage 110 includes stereo cameras 122 and 124 as imaging devices that recognize the calibration plates 118 and 120. By recognizing the images of the calibration plates 118 and 120 with the stereo cameras 122 and 124, the center coordinates are recognized from the outer frame and each dot of the calibration plates 118 and 120, and the relative positions with respect to the calibration plates 118 and 120 are recognized. Relationships and attitudes can be identified.

  In general, the image recognition of the calibration plates 118 and 120 is used to calibrate the distortion of the stereo cameras 122 and 124 themselves, the correction of the tilt due to the mounting position, or the deviation from the base coordinate system of the robot arm. On the other hand, in the manufacturing system 100, the result of the image recognition is to correct the inevitable positional deviation of the carriage 110 with respect to the work spaces 102, 104, and 106 that occurs when the carriage 110 stops (hereinafter, including “posture deviation”). Used.

  The stereo cameras 122 and 124 each have two or more lens mechanisms, and acquire depth information by simultaneously photographing the object from a plurality of different directions. Stereo cameras 122 and 124 are supported by pedestals 114 and 116 extending in the vertical direction, respectively. The gantry 114 extends in the substantially vertical direction (z-axis direction) from the front of the robot arm, and supports the stereo camera 122 at the tip thereof at substantially the same height as the lower calibration plate 118. The gantry 116 extends in a substantially “L” shape from the rear of the robot arm, and supports the stereo camera 124 at the tip thereof at substantially the same height as the upper calibration plate 120.

  Although the stereo cameras 122 and 124 are illustrated here as the imaging device, a monaural camera may be used as the imaging device. Note that the stereo cameras 122 and 124 are preferable for the image recognition of the calibration plates 118 and 120.

  The above-described misalignment correction is performed by the control device 126. The control device 126 includes a central processing unit (CPU), a storage device such as a ROM and a RAM. Here, the control device 126 is illustrated as being built in the cart 110, but the control device 126 may be installed outside the cart 110 and configured to transmit instructions from the control device 126 by wire or wirelessly. Good.

  The control device 126 also controls movement of the carriage 110 between the work spaces 102, 104, 106. Specifically, the carriage 110 includes wheels 128 (represented by reference numerals) as examples of drive mechanisms, servo motors (not shown) for driving the wheels 128, and the like, and the control device 126 is a servo motor. The movement between the work spaces 102, 104, and 106 is controlled by controlling a drive control unit (not shown) including an encoder (not shown) that detects the number of rotations and the rotation speed.

  Hereinafter, the positional deviation correction of the carriage 110 will be described in more detail.

  FIG. 4 is a flowchart illustrating the procedure for correcting the misalignment of the carriage 110. As illustrated in FIG. 4, as a preliminary preparation, first, the size of the calibration plates 118 and 120 attached to the work table 112 and the plate width L1 of the calibration plates 118 and 120 when the carriage 110 stops at the ideal position, The dot size S, pitch L2, and arrangement relationship are registered in the image processing program of the control device 126 (step 200).

  Next, for example, as shown in FIG. 1, the control device 126 instructs the carriage 110 working in the work space 102 to move to another work space 104, 106 according to the necessity on the production line (step 202). That is, the control device 126 moves the carriage 110 by a desired movement amount along the x axis. The desired amount of movement is achieved by controlling the rotation speed of the servo motor. The control device 126 stops the cart 110 after moving the cart 110 by a desired amount of movement (step 204).

  Next, the control device 126 executes image recognition based on images captured (captured) by the stereo cameras 122 and 124 and an image at an ideal position registered in the image processing program. And the control apparatus 126 determines whether the trolley | bogie 110 has faced the work spaces 104 and 106 from the result of image recognition. That is, the control device 126 determines whether or not the inclination of the carriage 110 with respect to the work spaces 104 and 106 is within an allowable amount based on the result of image recognition (step 206).

  In the manufacturing system 100, the calibration plates 118, 120 are installed horizontally with respect to the work spaces 102, 104, 106, and the work space of the carriage 110 is detected by detecting the inclination of the carriage 110 with respect to the calibration plates 118, 120. 102, 104, and 106 are configured to be inclined.

  FIG. 5 is an explanatory diagram of the stopper 130 provided on the bottom surface 110 a of the carriage 110. FIG. 5A is a schematic side view illustrating the operation of the stopper 130, and FIG. 5B is a schematic bottom view illustrating the position of the stopper 130.

  As illustrated in FIG. 5A, a stopper 130 that can be moved up and down is provided on the bottom surface 110 a of the carriage 110. When the inclination of the carriage 110 with respect to the work spaces 104 and 106 is not within the allowable amount (step 206 No), the control device 126 lowers the stopper 130 (step 212). Then, the control device 126 rotates the carriage 110 around the stopper 130 as the rotation center (step 214).

  Thereby, since the stopper 130 functions as a rotation shaft during the rotation of step 214, it can be avoided that the position of the carriage 110 is shifted or the carriage 110 is largely moved due to the rotation operation and the alignment is not achieved. Note that the rotation of the carriage 110 around the stopper 130 as the rotation center may or may not be grounded. When the wheel 128 is not in contact with the ground, it is necessary to provide a mechanism for rotating the carriage 110 around the stopper 130 as the center of rotation.

  The mechanism of the stopper 130 is not particularly limited as long as it can perform an elevating function. For example, the contact portion of the stopper 130 with the floor surface is composed of a rubber member having a high coefficient of friction, and the rubber member is moved up and down. The elevating mechanism that maintains close contact with the floor when the is lowered is constituted by a ball screw, a worm gear, or the like.

  As illustrated in FIG. 5B, the stopper 130 is installed on the coordinate axis set in the vertical direction in the base coordinate system of the robot arm 108. As a result, since the vertical coordinate axis is rotated and the tilt is corrected, the vertical coordinate axes of the coordinate system before the rotation and the coordinate system after the rotation do not change, and it is easy to grasp the coordinate system after the rotation. Become.

  Next, the control device 126 determines the work space 104 of the carriage 110 based on the result of image recognition based on the images captured (captured) by the stereo cameras 122 and 124 and the image at the ideal position registered in the image processing program. It is determined whether or not the inclination with respect to 106 has reached an allowable amount (step 216). When the inclination with respect to the work spaces 104 and 106 does not fall within the allowable amount (No in step 216), the control device 216 repeats the processes of step 214 and step 216 until the inclination falls within the allowable amount. When the inclination with respect to the work spaces 104 and 106 falls within an allowable amount (step 216 Yes), the control device 216 completes the rotation of the carriage 110 and raises the stopper 130 (step 218). Since the stopper 130 is lowered before the rotation of the carriage 110 and is raised after the rotation is completed, the stopper 130 does not hinder the movement between the work spaces 102, 104, 106.

  After step 206 Yes and step 218, the control device 126 determines that the cart is based on the result of image recognition based on the image captured (captured) by the stereo cameras 122 and 124 and the image at the ideal position registered in the image processing program. It is determined whether or not the lateral deviation amount 110 (deviation amount in the x-axis direction) is within an allowable range (step 208). When the lateral deviation amount of the carriage 110 is within an allowable range (Yes in Step 208), the control device 126 converts the image captured (captured) by the stereo cameras 122 and 124 and the image at the ideal position registered in the image processing program. From the result of the image recognition based on it, it is determined whether or not the vertical displacement amount (deviation amount in the y-axis direction) of the carriage 110 is within an allowable range (step 210). If the vertical displacement amount of the carriage 110 is within an allowable range (step 210 Yes), the stopper 130 is lowered again and fixed on the spot (step 211), and the positional deviation correction of the carriage 110 is completed. Here, it has been described that the stopper 130 is not lowered when moving to the other work spaces 104 and 106 in Step 202, but the stopper 130 is not limited to Step 208 and Step 210. When it is lowered, a process of raising the stopper 130 is performed.

  FIG. 6 is a diagram illustrating the relationship between the lateral shift correction and the vertical shift correction in the positional shift correction procedure of FIG. As illustrated in FIG. 6, the control device 126 moves the cart 110 in the x-axis direction toward the ideal position when the lateral shift amount of the cart 110 is not within the allowable range (No in step 208) based on the image recognition result (step 208). 220). Then, again, the image of the stereo cameras 122 and 124 and the image at the ideal position are compared to confirm the amount of lateral deviation, and the processing of step 208 and step 220 is repeated until the lateral deviation amount is within an allowable range. When the lateral displacement amount of the carriage 110 is within an allowable range (step 208 Yes), the vertical displacement amount is calculated by comparing the images of the stereo cameras 122 and 124 with the image at the ideal position, and the vertical displacement amount of the carriage 110 is calculated. Is not within the allowable range (step 210 No), the carriage 110 is moved in the y-axis direction toward the ideal position (step 222). Then, again, the image of the stereo cameras 122 and 124 and the image at the ideal position are compared to confirm the amount of vertical deviation, and the processing of step 210 and step 222 is repeated until the amount of vertical deviation is within an allowable range. FIG. 6 illustrates a case where both the lateral shift and the vertical shift are within the allowable amount by one movement (correction).

  FIG. 7 is an explanatory diagram when a lateral shift occurs. FIG. 7A compares the case where the carriage 110 stops at the ideal position (illustrated as “ideal example O1”) and the case where the carriage 110 stops laterally from the ideal position (illustrated as “lateral deviation example R1”). FIG. 7B is a diagram comparing images of the stereo cameras 122 and 124 of the ideal example O1 and the lateral deviation example R1. As illustrated in FIGS. 7A and 7B, the lateral displacement is a state in which the calibration plates 118 and 120 are displaced in the left-right direction of the image with respect to imaging (imaging) at the ideal position. In FIGS. 7A and 7B, the difference between the ideal position and the position deviated from the ideal position is indicated by reference numeral X1.

  FIG. 8 is an explanatory diagram when vertical shift occurs. FIG. 8A shows the case where the carriage 110 stops at the ideal position (illustrated as “ideal example O1”) and the case where the carriage 110 stops vertically after deviating from the ideal position (illustrated as “vertical deviation example R2”). FIG. 8B is a diagram comparing the images of the stereo cameras 122 and 124 of the ideal example O1 and the vertical deviation example R2. As illustrated in FIGS. 8A and 8B, the vertical shift is a state in which the calibration plates 118 and 120 are larger or smaller than the imaging (photographing) at the ideal position. In the image of FIG. 8B, since the carriage 110 is vertically shifted in the direction approaching the work spaces 104 and 106 in the example of FIG. 8A, the external shapes of the calibration plates 118 and 120 imaged at ideal positions. The contour R2 ′ of the calibration plates 118 and 120 is larger than O1 ′.

  In the flowchart of FIG. 4, the case where the carriage 110 working in the work space 102 is moved to the other work spaces 104 and 106 has been described, but the other work space 102, When moving to 106, the same applies to the case where the carriage 110 working in the work space 106 is moved to another work space 102, 104.

  Note that the flowchart is merely an example, and the procedure for correcting misalignment is not limited to this example. FIG. 9 is a flowchart illustrating a modification of FIG. In the example shown in FIG. 9, step 208 for determining whether or not the lateral displacement amount (the displacement amount in the x-axis direction) of the carriage 110 is within an allowable range and whether the vertical displacement amount (the displacement amount in the y-axis direction) of the carriage 110 is within an allowable range. Step 210 for determining whether or not the inclination of the carriage 110 with respect to the work spaces 104 and 106 is within an allowable amount is performed prior to Step 206 for determining whether or not the inclination is within an allowable amount. The modification is not limited to the example shown in FIG. 9, and a plurality of processes on the flowchart may be performed in parallel, or the order of lateral shift correction and vertical shift correction may be reversed.

  As described above, according to the manufacturing system 100 described above, the electronic component P is arranged on the tray T arranged in each of the work spaces 102, 104, and 106, so that there is no risk of positional displacement of the electronic component P in the tray T. . In addition, a robot arm 108 is placed on a carriage 110 and reciprocates between a plurality of work spaces 102, 104, 106 according to the convenience of the production line, and the positional accuracy with respect to each work space 102, 104, 106 is calibrated on the work table 112. Since it is secured by the image recognition of the motion plates 118 and 120, the work range of the robot arm 108 can be expanded.

  In addition, by arranging the calibration plates 118 and 120 as appropriate and operating the stereo cameras 122 and 124 as appropriate, a stable positional relationship is always established between the robot arm 108 and each of the work spaces 102, 104, and 106 (electronic parts P). Manufacturing operations can be carried out while ensuring.

  In the above-described example, the moving body is constituted by the cart 110 that can move and rotate in the horizontal direction and the vertical direction with respect to the work spaces 102, 104, and 106. Thereby, since it is not necessary to provide a magnetic tape, a magnetic bar, or a rail on the floor surface, a manufacturing system with a high degree of freedom and easy layout change is realized. In addition, as long as the object is set, it is possible to run freely.

  FIG. 9 is a diagram illustrating a manufacturing system 300 as a first modification of the manufacturing system 100. As shown in FIG. 9, the moving body detects the magnetism of a magnetic member laid on the floor surface by a magnetic sensor (not shown), and follows (induces) the magnetic member to run the robot arm 108. (Hereinafter simply referred to as “trolley 304”). Here, the magnetic tape 302 is illustrated as a magnetic member. Thereby, since the cart 304 travels following the magnetic tape 302, it is possible to ensure the movement accuracy as compared with the case where the magnetic tape 302 is not laid.

  FIG. 10 is a diagram illustrating a manufacturing system 400 as a second modification of the manufacturing system 100. As shown in FIG. 10, the moving body is a slider 404 that travels on a uniaxial frame 402 laid on the floor surface along the x-axis direction, and the robot arm 108 is placed on the slider 404. It may be an axis robot. As a result, the positional deviation in the y-axis direction and the z-axis direction does not occur in the mechanism, so that the positional deviation correction by the image recognition only needs to be in the x-axis direction. Therefore, it is possible to reciprocate between the work spaces 102, 104, and 106 while reducing the labor for correcting the misalignment.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to this example. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  The present invention can be used as a manufacturing system used in a production line such as a factory.

100, 300, 400 ... Manufacturing system 102, 104, 106 ... Work space 108 ... Robot arm 110, 304 ... Cart (moving body)
112... Work table 114, 116 .. Base 118, 120... Calibration plate (position identification mark)
122, 124 ... Stereo camera (imaging device)
126 ... Control device 128 ... Wheel 130 ... Stopper 302 ... Magnetic tape 402 ... Frame 404 ... Slider (moving body)
T ... Tray P ... Electronic parts

Claims (9)

In a manufacturing system in which manufacturing operations are performed in a plurality of work spaces,
A robot arm,
A moving body on which the robot arm is placed and reciprocates in the plurality of work spaces;
An imaging device provided in the moving body;
A form that can identify a position by image recognition, at least one position identification mark installed in each of the plurality of work spaces,
A control device that corrects the position of the moving body with respect to the work space by image recognition of the position identification mark using the imaging device;
A manufacturing system comprising:   The manufacturing system according to claim 1, wherein the movable body reciprocates in the plurality of work spaces following a magnetic member provided on a floor surface.   The manufacturing system according to claim 1, wherein the movable body moves along a fixed single axis and reciprocates in the plurality of work spaces.   The manufacturing system according to claim 1, wherein the movable body is a cart that is movable and rotatable in a horizontal direction and a vertical direction with respect to the work space, and reciprocates in the plurality of work spaces. Having a stopper that can be raised and lowered on the bottom of the carriage,
5. The manufacturing system according to claim 4, wherein the control device lowers the stopper before the carriage is rotated and uses the stopper as a rotation center. Having a stopper that can be raised and lowered on the bottom of the carriage,
The manufacturing system according to claim 4, wherein after the correction of the position of the carriage is completed, the control device lowers the stopper and fixes the stopper at the position.   The manufacturing system according to claim 5, wherein the control device raises the stopper when the carriage moves.   The manufacturing system according to claim 5, wherein the stopper is installed on a coordinate axis set in a vertical direction in a base coordinate system of the robot arm. The plurality of work spaces are provided on a workbench;
The position identification mark is installed on the workbench;
The manufacturing system according to any one of claims 1 to 8, wherein the imaging device is a stereo camera, and the stereo camera is supported by a pedestal extending in a vertical direction from the moving body.