JP2021096081A - Three-dimensional connector measurement method, connector gripping position calculation method, connector gripping method, connector connection method, and connector - Google Patents

Abstract

To provide a method of quickly and stably measuring the orientation and position of a small connector connected to a cable.SOLUTION: A three-dimensional connector measurement method is provided, comprising: an image acquisition step for photographing a connector 10 connected to tips of cables 35 using a three-dimensional measurement device 55 to acquire a connector image, the connector having substantially a prismatic shape with a bottom face 11 having the cables coming out therethrough, a plurality of side faces 14, and a plurality of longitudinal sides 16 acting as borders between the side faces, where a first side face 15, one of the side faces, has a mark 30 provided thereon; a recognition step for recognizing the mark from the connector image; and a three-dimensional measurement step for computing the orientation and position of the connector based on the recognized mark.SELECTED DRAWING: Figure 1

Description

The present invention relates to a three-dimensional measurement method for automatically handling a connector with a robot hand, and a method for connecting a connector with a robot hand. The present invention also relates to a connector suitable for being a target of such a three-dimensional measurement method and a connection method.

Attempts have been made to automate the connection by grasping the connector with a robot hand. In many cases, the procedure of grasping the male connector connected to the end of the cable from the side with respect to the connection direction and inserting it into the female connector is adopted. This is because when the cable is gripped, it is difficult to push the male connector into the female connector because the cable is flexible, and the cable may be broken.

In Patent Document 1, the coupler (connector) is irradiated with a slit-shaped laser beam, the position and orientation of the coupler are detected by an optical cutting method, the side surface of the coupler is gripped by the front gripping claw, and the coupler and the other are gripped. A method for automatically connecting a wire harness by separating the front gripping claw and pushing it from the back surface of the coupler with the rear gripping claw when a contact state of the coupler is obtained is described.

Patent Document 2 describes a method in which predetermined marks are provided on each of two connectors, and after the connectors are connected, it is determined whether or not the connectors are in an appropriate mating state by using the marks. Has been done.

Japanese Unexamined Patent Publication No. 6-188061 Japanese Unexamined Patent Publication No. 63-225480

However, in the method described in Patent Document 1, since the position and orientation of the connector are detected by three-dimensionally measuring the connector itself, the size and shape of the various existing connectors, the reflection characteristics of the surface, and the like may be affected. Especially when the connector is small, the detection result may become unstable. Further, in the method described in Patent Document 1, the structure of the robot hand becomes complicated, and it is not easy to control the front and rear gripping claws.

Even for a connector in which almost the entire male shape is inserted into a female shape as described in Patent Document 1, an operation such as grasping the male shape connector with a robot hand and changing the connector is performed. It is desirable to be able to connect to the female connector as it is without any problems. For that purpose, for example, it is necessary to grip the rear edge portion with respect to the connection direction of the male connector, and in order to grip the rear edge portion, the position and orientation of the rear edge of the male connector are determined. It is necessary to obtain it accurately. However, when a small connector is connected to the end of the cable, it has been difficult to accurately measure the position and orientation of the rear edge of the connector. There is a problem that it is difficult to accurately extract the rear edge, especially when the thickness of the cable and the width of the connector are relatively close to each other.

The mark provided on the connector of Patent Document 2 is for determining the fitting state, and is not for three-dimensional measurement of the connector, gripping by a robot hand, or connection operation.

The present invention has been made in consideration of the above, and is to enable the robot hand to grip the rear edge of the connector at a predetermined position, for example, in the connection direction, and connect to the other connector in a high-speed and stable manner. It is an object of the present invention to provide a three-dimensional measurement method of the connector and a connection method of the connector by a robot hand. At the same time, it is an object of the present invention to provide a connector suitable for the target of such a three-dimensional measurement method and a connection method.

In order to solve the above problems, the present invention uses a connector having a mark on the side surface, and calculates the orientation and position of the connector based on the three-dimensional measurement result of the mark.

Specifically, in the three-dimensional measurement method of the connector of the present invention, a plurality of side surfaces and a plurality of borders between the adjacent side surfaces are connected to the tip of the cable and the surface from which the cable is pulled out is used as the bottom surface. An image acquisition step of acquiring a connector image by imaging a connector having a substantially prismatic shape having vertical sides and having a mark on the first side surface, which is one of the side surfaces, with a three-dimensional measuring device, and the connector. It has a recognition step of recognizing the mark from an image and a three-dimensional measurement step of calculating the orientation and position of the connector based on the recognized mark.

Here, the surface from which the cable is pulled out is the surface to which the cable is connected, or when the cable is connected inside the connector, among the substantially prismatic outer shapes of the connector, the cable penetrates the substantially prismatic shape. The side to do. Three-dimensional measurement means acquiring orientation, position, or both in three-dimensional space. A mark is a figure that can be recognized by a three-dimensional measuring device and can be measured three-dimensionally.

By this method, the orientation and position of the connector can be measured at high speed and stably. In addition, even when the connector is small and connected to a cable, the orientation and position of the connector can be measured accurately.

Preferably, the three-dimensional measuring device is a stereo camera. In this case, the connector image consists of two images having different viewpoints.

Preferably, the mark is a linear mark that crosses the first side surface, and the recognition step further touches the mark among two vertical sides forming the contour of the connector from the connector image1. Recognizing the reference vertical side of the book, the three-dimensional measurement step determines the orientation of the connector based on the three-dimensional measurement results of at least three points on the reference vertical side or on the mark that are not on a straight line. And calculate the position. When the mark crosses the first side surface, it means that the mark is formed from one vertical side of the first side surface to the other vertical side. Further, here, when the vertical side is in contact with the mark, it means that the mark is in contact with the vertical side because either end point of the linear mark is on the vertical side.

Alternatively, preferably, the mark comprises a set of one or more points on each of the two vertical sides at both ends of the first side surface, and the recognition step is further described from the connector image of the connector. Of the two vertical sides constituting the contour, one reference vertical side in contact with the mark is recognized, and the three-dimensional measurement step calculates the orientation and position of the connector based on the reference vertical side and the mark. To do. A set of points existing on each of the two vertical sides at both ends of the first side surface is one or more points on one of the two vertical sides at both ends of the first side surface. Means a set of points and one or more points on the other vertical side. The mark may consist of two points located on each of the two vertical sides at both ends of the first side surface, and there are two or more points on one or both of the two vertical sides. You may be doing it. Further, here, when the vertical side is in contact with the mark, it means that the mark is in contact with the vertical side because one of the points constituting the mark is on the vertical side.

Alternatively, preferably, the mark may be a mark that occupies a certain area on the first side surface. Here, when the mark occupies a certain area, it means that the mark spreads in the two-dimensional direction on the first side surface. When a mark consists of a plurality of figures provided with spaces separated from each other, the plurality of figures and the intervening space are regarded as one mark. Further, the fact that the mark occupies a certain area includes the case where the mark is composed of a plurality of points or lines and a group of points or lines extends to an area having a certain area.

Preferably, the connector has a substantially rectangular parallelepiped shape. Here, in the substantially rectangular parallelepiped shape, some of the vertical sides are chamfered, or ridges or concave grooves parallel to the side surfaces or vertical sides are formed depending on the purpose such as limiting the orientation of the connector or the configuration of parts. Including the case where it is. The substantially rectangular parallelepiped shape is the most common shape of the connector, which makes it easy to apply the present invention, and there is a high probability that the mark can be recognized even when the connector is placed in a random orientation.

Preferably, the first side surface is the widest side surface of the side surfaces of the connector. The width of the side surface means the distance between the vertical sides at both ends of the side surface. Since the mark is long in the width direction of the side surface, it is possible to maintain high measurement accuracy when measuring the mark three-dimensionally.

Preferably, the connector is a male connector and the mark is formed on the first side surface at a portion inserted into the corresponding female connector. In such a case, since there is no other effective method for three-dimensionally measuring the connector, there is a particular merit in applying the present invention.

In the method for calculating the gripping position of the connector of the present invention, the connector is moved by a robot hand based on the step of performing the three-dimensional measurement of the connector using any of the above three-dimensional measurement methods and the three-dimensional measurement result of the connector. It has a gripping position calculation step of calculating a gripping position at the time of gripping.

The connector gripping method of the present invention includes a gripping step of gripping the gripping position with a robot hand after carrying out the gripping position calculation method of the connector.

The connector connection method of the present invention further includes a connection step of carrying out the connector gripping method and then connecting the connector gripped by the robot hand to the paired mating connector by operating the robot hand. ..

The connector of the present invention has a substantially prismatic shape with the surface from which the cable to be connected is drawn out as the bottom surface, and has a mark for three-dimensional measurement on the first side surface, which is one of the side surfaces adjacent to the bottom surface.

According to the three-dimensional measurement method and connection method of the connector of the present invention, the orientation and position of the connector can be measured quickly, stably and accurately even when the connector is small and connected to the cable, and the gripping the connector is gripped. The position can be calculated effectively. In addition, the calculated gripping position can be gripped with an appropriate robot hand, and can be connected to the connector of the other party to be paired. The connector of the present invention is suitable for being the target of such a three-dimensional measurement method and a connection method.

The connector and the mating connector handled in the first embodiment of the present invention. It is a figure for demonstrating that the robot hand grips the rear edge portion of a connector. It is an overall system for carrying out the first embodiment of the present invention. It is a process flow diagram of 1st Embodiment of the 3D measurement method and connection method of the connector of this invention. A is an image of a connector, and B: a cable area, a C connector area, and D: a mark area extracted from the image. A is a diagram showing the extracted cable area in which FIG. 5B is reprinted, B: a plurality of points along the center of the cable, and C: the orientation of the cable. A: The extracted connector area in which FIG. 5C is reprinted, and B: the orientation of the contour vertical side of the connector. It is a figure for demonstrating the calculation method of the orientation and shape of a connector. It is a process flow diagram of the 2nd Embodiment of the 3D measurement method and connection method of the connector of this invention. Examples of the connector are A: plan view, B: front view, C: right side view, D rear view, and E: bottom view. It is a perspective view of the connector shown in FIG. A to C: Examples of marks provided on the connector shown in FIG. 10 and handled in the first embodiment of the present invention. A to F: Examples of connector marks provided on the connector shown in FIG. 10 and handled in the second embodiment of the present invention. Other examples of the connector are A: plan view, B: front view, C: right side view, D rear view, and E: bottom view. It is a perspective view of the connector shown in FIG. A to E: Examples of connector marks provided on the connector shown in FIG. 14 and handled in the second embodiment of the present invention. Other examples of the connector are A: plan view, B: front view, C: right side view, D rear view, and E: bottom view. It is a perspective view of the connector shown in FIG. A to E: Examples of connector marks provided on the connector shown in FIG. 17 and handled in the second embodiment of the present invention.

The first embodiment of the connector of the present invention, the three-dimensional measurement method of the connector, the method of calculating the gripping position of the connector, the method of gripping the connector, and the method of connecting the connector will be described with reference to FIGS. 1 to 8 and 10 to 11.

With reference to FIG. 1, the connector 10 handled in this embodiment is a male connector having a substantially rectangular parallelepiped shape. The connector is connected to the tip of the cable 35, and the cable connected to the terminal inside the connector is pulled out from the bottom surface 11 behind the connector. The bottom surface of the connector is formed in a brim shape (12), four side surfaces 14 are provided adjacent to the bottom surface, and the adjacent side surfaces are separated by a vertical side 16. A linear mark 30 is formed on the first side surface 15 of the side surfaces 14, that is, from one vertical side to the other vertical side of the first side surface.

The connector 10 is connected to the mating connector 25, which is a female connector. At this time, the connector is connected by inserting the insertion portion 20 which occupies most of the bottom surface except the collar 12 into the inside of the mating connector 25, and inserting the pin 26 of the mating connector into the two connection holes 22 of the connector tip 19. The connector. Two concave grooves 21 are provided on the first side surface 15 of the connector, and when connecting to the mating connector, the connector is connected in a predetermined direction by fitting with a ridge inside the mating connector. Is guaranteed.

With reference to FIGS. 1 and 2, in order to grip such a connector 10 with the robot hand 51 and connect it to the mating connector 25, it is necessary to grip the connector so as to sandwich the rear edge 13 of the connector. The robot hand shown in FIG. 2 has a pair of grip portions 52, and a V-shaped groove 53 formed so as to face the vicinity of the tip of each grip portion sandwiches the opposite side of the collar 12 which is the rear edge. As a result, the connector is gripped in the correct orientation, and the orientation of the connector does not shift even after gripping. Further, when connecting the connector 10 to the mating connector 25, the connector 10 can be pushed in from the rear by the slope of the V-shaped groove 53 on the base side of the robot hand 51. As a result, it is possible to prevent slippage between the connector 10 and the robot hand 51 even during the connection operation of the connector.

Returning to FIG. 1, that the shape of the connector 10 is substantially rectangular parallelepiped means that some vertical sides 16 are chamfered and some vertical sides are stripped of prismatic regions. A shape having concave grooves and ridges parallel to the connecting direction of the connector on some side surfaces 14, a shape having a hook-shaped locking portion to prevent the connector from coming off, and to prevent incomplete insertion of terminals. A shape having a holder of the above is included. The shape of the connector is generally a substantially rectangular parallelepiped shape, but is not particularly limited. For example, a cross section perpendicular to the connection direction (hereinafter referred to as a "cross section") is a substantially parallelogram or a substantially trapezium. It may be a polygon other than a quadrangle.

As for the size of the connector 10, the smaller the size, the greater the merit of applying the method of the present embodiment. For example, the method of the present embodiment can be preferably applied to a connector having one or more side surfaces or bottom surfaces having a size of 20 mm × 20 mm or less, further 10 mm × 10 mm or less, and further 5 mm × 5 mm or less. ..

The mark 30 crosses the first side surface 15. The mark 30 is preferably a straight line crossing the first side surface 15, as shown in FIG. However, the present invention is not limited to this, and for example, the mark 30 may be a curved line, a dotted line, or a broken line. Further, in an extreme case, the mark 30 may consist of two points located on two vertical sides at both ends of the first side surface. Further, it is preferable that the mark 30 is provided at a position closer to the tip end side or the bottom surface side of the connector from the center of the first side surface 15. This is because the tip end side of the connector can be easily and accurately recognized in the three-dimensional measurement of the mark 30, which will be described later.

The mark 30 is composed of a color different from that of the first side surface 15 of the connector 10, and is preferably composed of a color having a strong contrast with the first side surface. The mark 30 may be provided by attaching a paint or a sticker to the connector 10 for position recognition. Further, the mark may be a portion in which a portion constituting the connector such as the above-mentioned concave groove, ridge, locking portion, or holder is formed in a color different from that of the first side surface. Here, the different colors are not limited to the colors that can be discriminated by visible light, and the reflection spectra of infrared rays and ultraviolet rays may be different depending on the wavelength of light used by the three-dimensional measuring device that measures the mark 30. ..

The first side surface 15 on which the mark 30 is formed is preferably the widest side surface among the side surfaces 14 of the connector 10. The width of the side surface means the distance between the vertical sides at both ends of the side surface. This is because by providing the mark on the wide side surface, the mark can be formed longer in the width direction of the side surface, and high accuracy can be obtained in the three-dimensional measurement of the mark 30 described later. Note that the fact that the mark is long in the width direction of the side surface is not limited to the fact that the linear mark is formed long in the width direction of the side surface as shown in FIG. 12A below, as shown in FIGS. 12B and 12C. Includes that the area marked with extends long in the width direction of the side surface.

Further, when the connector 10 is a male type, the mark 30 may be formed on the insertion portion 20 to be inserted into the mating connector 25 on the first side surface.

With reference to FIG. 3, the overall system for carrying out the method of this embodiment includes a robot 50 and a stereo camera 55 which is a three-dimensional measuring device. The connector 10 connected to the cable 35 is supplied by an appropriate method, three-dimensionally measured by the stereo camera 55, gripped by the robot hand 51 of the robot 50, and connected to the other party connector.

As the robot 50, a known articulated robot can be preferably used. The robot is provided with a robot hand 51 at the tip of the arm, and the connector 10 is gripped by the grip portions 52 and 52 of the robot hand. The robot is controlled by the robot control unit 54.

The three-dimensional measuring device is not particularly limited as long as it can acquire an image capable of three-dimensional measurement of the connector. Examples of the three-dimensional measuring device include a stereo camera using the principle of triangulation, a device by an optical cutting method, a TOF camera, a three-dimensional measuring device using a laser, and the like. When using a device that acquires a distance image without color information, such as a general TOF camera, for example, a two-dimensional camera is used to separately acquire a color image without distance information, and the distance image and the color image are combined. Therefore, the mark can be recognized and extracted from the distance image.

As the three-dimensional measuring device, a stereo camera 55 is preferably used. A stereo camera is suitable for accurately measuring an object at a short distance in three dimensions. The stereo camera is equipped with two cameras 56 and 56, and finds the corresponding point of the point to be measured on two images taken from different viewpoints, and from the positional relationship of the two cameras, the measurement point is measured by the principle of three-dimensional surveying. Calculate the three-dimensional position of. The stereo camera is controlled by the stereo camera control unit 57, such as imaging. Further, the calculation for the three-dimensional measurement of the object may be performed by the stereo camera control unit 57 or may be performed by an external computer.

The method of this embodiment will be described with reference to the process flow of FIG.

(S1) First, the above-mentioned connector 10 is prepared. The three-dimensional shape of the connector and the position of the mark 30 on the connector are obtained in advance from a design drawing or the like. The connector is arranged so that it can be gripped by the robot hand 51 while being connected to the tip of the cable 35. For example, one or more of the connectors and cables may be placed upright in a tubular container or the like with the connectors on top, or may be placed on a table. Further, the connector 10 may be prepared in a state where the other end of the cable is connected to the substrate and the cable and the connector extending from the substrate are hung in the air. It is not necessary to align the rotation directions around the axis of the connector.

(S2) The connector 10 is imaged by the stereo camera 55, and two images from different viewpoints are acquired as connector images.

(S3) It is confirmed whether or not the mark 30 is captured in the two images. If the mark 30 is not imaged, the mark 30 is on the back side of the connector 10 when viewed from the stereo camera 55. If possible, change the imaging direction or move the connector 10 and the cable 35 a little to restart the image. Alternatively, when a plurality of connectors are arranged, the target may be changed to another connector for imaging. If the connector is a substantially rectangular parallelepiped, that is, if the cross section of the connector is approximately rectangular, the mark is imaged with a probability of about 1/2 even if the rotation method around the axis of the connector is randomly supplied. .. When the cross section is approximately pentagonal or larger, the probability that a mark will be captured in the image is low.

(S4) The cable 35 is extracted from the two images, and the direction of the cable is measured. The specific processing is as follows, for example. For each of the two images (FIG. 5A), the area of the connector 10 and the cable 35 is extracted by binarization or the like, and the area of the cable is separated from this (FIGS. 5B and 6A). The position coordinates of a plurality of points along the center of the cable are obtained (FIG. 6B), and the orientation of the cable is calculated using several points on the tip side (connector side) (FIG. 6C). It is not necessary to accurately determine the cable orientation obtained in this process.

(S5) The connector 10 is extracted from the two images, and the two vertical sides 16 appearing on the outline of the connector are detected. The specific processing is as follows, for example. For each of the two images, the rest of the cable region separated from the connector 10 and cable 35 regions in the previous step S4 is extracted as the connector region (FIGS. 5C and 7A). Then, of the contour of the connector, the portion where the direction and inclination of the cable obtained in the previous step S4 are close to each other is determined as the vertical side, and the two vertical sides on both sides of the contour of the connector are detected (FIG. 7B). In the following, the vertical side forming the contour of the connector on the image is referred to as a "contour vertical side".

In the extraction of the connector 10, the extracted connector region may include a part of the cable 35. If the connector is connected to a cable, it is difficult to extract just the connector accurately. In particular, when the connector is small and there is not much difference between the width of the connector and the thickness of the cable, it is difficult to accurately extract the contour of the bottom surface from which the cable is pulled out. Therefore, although it is possible to accurately measure the orientation of the contour vertical side in this step S5, it is difficult to determine the positions of both ends of the contour vertical side. In the method of the present embodiment, as will be described later, the positions of both ends of one of the contour vertical sides are determined based on the three-dimensional measurement result of the mark 30.

(S6) The mark 30 is extracted from the two images. Next, by examining the positional relationship between the mark 30 and the two contour vertical sides, it is determined that the contour vertical side of the two contour vertical sides that is in contact with the mark is the vertical side at the end of the first side surface 15. , Select as the reference vertical side and calculate its orientation. The vertical edge of the contour that is in contact with the mark is the vertical edge of the contour in which either end point of the mark is located on the vertical edge of the contour. The specific processing is as follows, for example.

In order to extract the mark from the first side surface 15, a binarization process is performed using a threshold value different from that for extracting the connector 10 in the previous step S6 (FIG. 5D). At this time, it is preferable that the mark is provided in a color having a strong contrast with the first side surface. In order to distinguish the mark from the other portion of the first side surface, the mark can be extracted based on the brightness value of the color having the largest difference between the brightness values of RGB among the RGB brightness values of the image. For example, when the first side surface is white or black and the mark is provided in red, the mark can be extracted based on the R image.

Next, using the extracted mark 30, the contour vertical side of the two contour vertical sides that is in contact with the mark is set as the reference vertical side. With reference to FIG. 8, the mark crossing the first side surface 15 always touches the two vertical sides at both ends of the first side surface. Of these, the vertical side forming the contour of the connector in the two images is selected as the reference vertical side 17. Then, the orientation of the reference vertical side is calculated by obtaining the position coordinates of a plurality of points from the two images along the reference vertical side by using the triangulation method. Details of the method for determining the position of the reference vertical side will be described later in step S8.

When one of the two cameras 56 and the connector 10 face each other, the mark 30 may come into contact with both of the two contour vertical sides. In that case, the reference vertical side may be selected based on the image taken by another camera. When the connector is imaged from a close distance with a stereo camera, the contour vertical sides in contact with the marks may be located on opposite sides of the two left and right images. In this case, since the reference vertical sides of the two images do not correspond to each other, the image of the connector 10 is restarted.

(S7) The position of the end point of the mark is calculated from the two left and right images by using the triangulation method.

(S8) The orientation and position of the entire connector 10 are calculated based on the orientation of the reference vertical side obtained in step S6 and the position of the end point of the mark obtained in step S7. The specific processing is as follows, for example.

With reference to FIG. 8, when the first end point 31 of the mark 30 is on the reference vertical side 17, the distances x and y from the first end point to both ends of the reference vertical side are known. The positions of both ends A and B can be determined on the calculated straight line of the reference vertical side. Further, the orientation of the first side surface 15 can be determined by the orientation of the reference vertical side 17 and the position of the second end point 32. Thereby, the position of the first side surface 15, for example, the positions of the four angles A, B, C, and D can also be determined. That is, the position and orientation (three-dimensional coordinates) of the first side surface 15 on which the mark exists can be determined based on the reference vertical side 17 and one point on the mark 30. Further, since the thickness t of the connector is also known, it is possible to determine the positions of all eight corners of the connector 10 in a substantially rectangular parallelepiped shape. The same applies when the second end point 32 of the mark 30 is on the contour.

Even if the shape of the connector is not a rectangular parallelepiped but a more complicated shape, the orientation and position of the entire connector can be similarly determined from the orientation of the first vertical side and the position of the second end point. That is, if the orientation of the reference vertical side 17 and the orientation and position of the mark are known, the shape data of the connector registered in advance in the three-dimensional coordinate space is fitted based on the three-dimensional coordinates of the reference vertical side and the mark. By doing so, the orientation and position of the entire connector can be easily determined.

In this way, in order to calculate the orientation and position of the connector based on the reference vertical side 17 and the mark 30, measure the positions of at least three points on the reference vertical side or on the mark that are not on a straight line. Just do it. It should be noted that calculating the orientation of the reference vertical side is the same as finding the positions of two points on the reference vertical side.

(S9) The gripping position is calculated from the three-dimensional information of the orientation and position of the connector 10. An appropriate position is calculated as the gripping position according to the work content after gripping the connector with the robot hand and the shape of the connector. In the present embodiment, since the connector is inserted into the mating type connector after gripping the connector, in FIG. 2 as an example, the orientation and position are obtained by using the opposite sides of the collar 12 of the connector as the gripping position.

(S10) The robot hand 51 grips the connector 10. Taking FIG. 2 as an example, the opposite sides of the flange 12 of the connector are sandwiched by the V-shaped groove 53 formed so as to face the vicinity of the tip of the grip portion 52.

(S11) After gripping the connector 10 with the robot hand 51, the gripping state may be confirmed. For example, the stereo camera 55 takes an image of the grip portion 52 of the robot hand, and confirms whether the connector is imaged between the grip portions. Whether or not the connector is imaged may be confirmed by checking whether or not the mark 30 is present in the captured image. This makes it possible to determine whether or not the connector has been successfully gripped by the robot hand.

Further, in the robot hand 51 shown in FIG. 2, since the two opposing sides of the collar 12 are sandwiched by the V-shaped groove 53, even if the calculated orientation and position of the collar include some errors, the connector 10 The orientation is corrected to the correct orientation, but the position of the connector may be shifted in the direction orthogonal to the connection direction and the holding direction (vertical direction in FIG. 2). In this case, the presence or absence of such a deviation can be confirmed by three-dimensionally measuring the position of the mark 30 or the position of another portion on the connector while the robot hand holds the connector. If the position of the connector is misaligned, the connector can be temporarily placed on a temporary stand or the like, the robot hand can loosen the pinch to correct the misalignment, and then the connector can be pinched again.

(S12) The robot hand 51 is moved to connect the connector 10 to the mating connector 25.

By the above method, the orientation and position of the connector 10 can be measured, grasped by the robot hand 51, and connected to the other party connector 25. If possible, the order of each step may be changed in an order different from the above description.

10 to 12 show examples of connectors and marks used in the method of this embodiment. FIG. 10 is a six-view view of the connector 10, and the left side view is omitted because it appears symmetrically with the right side view (FIG. 10C). FIG. 11 is a perspective view of the connector 10 shown in FIG. A metal terminal (not shown) is crimped to the tip of the cable, and the metal terminal is charged into the connector 10 from a convex terminal inlet provided on the bottom surface 11 of the connector 10. With reference to FIG. 1, when the pin 26 of the mating connector 25 is inserted into the connection hole 22, it comes into contact with the metal terminal and is electrically connected. FIG. 12 is an example of a mark on the first side surface 15 shown in the front view (FIG. 10B) of the connector 10 shown in FIG. 10, and the hatched portion is the mark 30. The detailed shape of the connector is not important.

The mark used in the present embodiment needs to cross the first side surface 15 from one vertical side to the other vertical side. The shape of the mark may be a single straight line as shown in FIGS. 1 and 8, and the position of the straight line may be different from this as shown in FIG. 12A. Further, the mark may be a broken line or a dotted line as shown in FIG. 12B.

Further, as shown in FIG. 12C, the mark 30 may consist of two points located on two vertical sides at both ends of the first side surface 15. In the mark consisting of two points, the orientation and position of the entire connector 10 are obtained by measuring the positions of two points on one vertical side and the points of the mark on the other vertical side in total. be able to. Alternatively, the orientation and position of the entire connector 10 can be obtained by measuring the positions of the two points on one vertical side and the three points of the midpoints of the two points forming the mark. More precisely, it is not on a straight line out of a set consisting of (a) points on one vertical line, (b) points that make up the mark, and (c) points that are uniquely positioned by the points that make up the mark. By measuring the positions of three or more points, the orientation and position of the entire connector can be obtained.

According to the three-dimensional measurement method and connection method of the connector of the present embodiment, even when the connector is small and connected to the cable, the orientation and position of the connector can be accurately determined by using the three-dimensional measurement result of the mark 30. Can be measured. As a result, for example, even for a connector in which almost the entire male shape is inserted into the female shape, the robot hand grips the rear edge with respect to the connection direction of the male shape connector and pushes it into the female shape connector. Can be done.

The second embodiment of the connector of the present invention, the three-dimensional measurement method of the connector, the method of calculating the gripping position of the connector, the method of gripping the connector, and the method of connecting the connector will be described with reference to FIGS. 9 to 11 and 13 to 19. .. The present embodiment is different from the first embodiment in that the mark formed on the connector is a mark that occupies a certain area on the first side surface.

10 to 11 and 13 to 19 show examples of connectors and marks used in the method of this embodiment. FIG. 13 is an example of a mark on the first side surface 15 shown in the front view (FIG. 10B) of the connector shown in FIGS. 10 and 11. FIG. 14 is a six-view view of an example of another connector, and the left side view is omitted because it appears symmetrically with the right side view (FIG. 14C). FIG. 15 is a perspective view of the connector 40 shown in FIG. FIG. 16 is an example of a mark on the first side surface 15 shown in the front view (FIG. 14B) of the connector 40 shown in FIG. 14, and the portion hatched by the diagonal line is the mark 42. FIG. 17 is a six-view view of another connector example, and the left side view is omitted because it appears symmetrically with the right side view (FIG. 17C). FIG. 18 is a perspective view of the connector 41 shown in FIG. FIG. 19 is an example of the mark on the first side surface 15 shown in the front view (FIG. 14B) of the connector 41 shown in FIG. 17, and the portion hatched by the diagonal line is the mark 42. Even in this embodiment, the detailed shape of the connector is not important.

The mark used in this embodiment occupies a certain area on the first side surface 15. The fact that the mark occupies a certain area includes the case where the mark consists of a plurality of points or lines and a group of points or lines extends to an area having a certain area (for example, FIGS. 13A to 13C and E). 16A and 16B, 19D). In FIG. 13E, the mark 42 forms one mark including one point on one vertical side, two points on the other vertical side, and a space separating the three points. Further, the first side surface may have a different color from the other side surfaces, and the entire first side surface may constitute one mark (for example, the mark shown in FIG. 13D). In addition, unlike the first embodiment, the mark does not have to touch the vertical side. Therefore, the length of the first side surface of the mark 42 shown in FIG. 13 in the width direction may be appropriately changed.

The shape of the mark 42 is preferably a simple shape having three or more feature points such as corners or intersections of line segments. Further, it is preferable that the intersections of corners and line segments have a shape that can be easily identified on the connector image. This is because even if the mark 42 is small, it is easy to search for corresponding points in the left and right images of the stereo camera. As an example of such a mark shape, a polygon having a triangle or more, preferably having an internal angle of 3 or more or an outer angle of 120 degrees or less, two or more straight lines are connected, and the angle of the connecting portion is preferable. Those having 120 degrees or less, those having two or more straight lines intersecting and having an intersection angle of preferably 90 ± 30 degrees, those having two or more straight lines arranged apart from each other, preferably arranged parallel to each other. Alternatively, a combination of these can be mentioned. If the mark has such a simple shape, the position and orientation of the connector can be calculated more quickly and stably by the stereo method.

Preferably, the mark 42 is formed in a color having a strong contrast with the first side surface 15 of the connector 40, or is formed in the insertion portion 20 into which the mark 42 is inserted into the mating connector 25 when the connector is male. It may be the same as the first embodiment.

Further, preferably, the first side surface 15 on which the mark 42 is formed is the widest side surface among the side surfaces of the connector, which is the same as that of the first embodiment. This is because by providing the mark on the wide side surface, the mark can be formed longer in the width direction of the side surface, and high accuracy can be obtained in the three-dimensional measurement of the mark. Note that the fact that the mark is long in the width direction of the side surface is not limited to the fact that the band-shaped mark is formed long in the width direction of the side surface as shown in FIGS. 16C and D and 19A, B and E. 16A and B, as shown in FIG. 19D, includes the area where the mark is provided extending long in the width direction of the side surface.

As shown in FIGS. 14 and 17, when the shape of the connector is such that it is difficult to detect the vertical side of the connector from the image, a mark capable of detecting the orientation of the vertical side of the connector is preferable. For example, as shown in FIGS. 16B to 16E and 19A to 19A, the vertical side direction of the connector can be changed by providing a mark having a certain length in the vertical side direction of the connector (vertical direction of FIG. 16 or 19). It can also be detected. In this case, the detection accuracy is improved when the length of the mark in the vertical side direction is preferably 0.2 mm or more, more preferably 0.25 mm or more, and further preferably 0.3 mm or more. In this case, the mark does not have to touch the vertical side.

The overall system for carrying out the three-dimensional measurement method and the gripping method of the connector of the present embodiment is the same as that of the first embodiment.

The method of this embodiment will be described with reference to the process flow of FIG.

Steps S1 to S3 and S8 to S12 are the same as those in the first embodiment.

When the mark 42 is captured in the two images captured by the stereo camera 55 in step S3, the mark 42 is extracted and the orientation and position thereof are three-dimensionally measured (S17). The method for extracting the mark 42 can be performed in the same manner as in step S6 of the first embodiment. Next, three or more characteristic points on the mark 42 are selected from the two images as corresponding points, and the three-dimensional position is calculated by the principle of triangulation surveying. As a result, the orientation and position of the mark 42 in the three-dimensional space can be acquired. Since the three-dimensional shape of the connector 40 and the position of the mark 42 on the connector are known in known connector design drawings such as CAD data, the orientation and position of the entire connector 40 are determined from the orientation and position of the mark 42. it can.

An example of a specific three-dimensional position calculation method will be described using the mark of FIG. 16B as an example. The mark in FIG. 16B is composed of two vertical lines on the left side and a vertical line on the right side. Calculate the three-dimensional position of either the left or right vertical line. In addition, the three-dimensional position of the straight line connecting the midpoints of the left and right vertical lines is calculated. The three-dimensional position of the mark 42 is calculated from the three-dimensional position of the calculated vertical line and the straight line connecting the midpoints. Further, the mark 42 in FIG. 16D has a constant width in both the width direction and the vertical direction. Therefore, it is possible to calculate the three-dimensional positions of the vertical side edge and the horizontal side edge of the mark, and thereby the three-dimensional position of the mark 42 can be calculated.

If the mark 42 has symmetry, the cable is extracted and the orientation is measured (step S4 in the first embodiment) before the step S17, or the cable 35 is obtained from the image captured by the stereo camera 55. By obtaining the positional relationship of the mark 42, it is possible to know the direction of rotation of the extracted mark 42 in the first side surface 15.

In order to improve the accuracy of the three-dimensional measurement of the connector by the method of the present embodiment, it is effective to increase the measurement accuracy of the orientation and position of the mark 42, and for that purpose, the characteristic in the mark 42 for calculating the three-dimensional position. It is preferable that the points are distributed as widely as possible in the first side surface 15. For this reason, it is preferable that the first side surface 15 on which the mark 42 is formed is the widest side surface among the side surfaces 14 of the connectors 10, 40, and 41.

The present invention is not limited to the above embodiment, and can be implemented in various other aspects within the scope of the technical idea of the invention.

For example, the mark of the present invention may further include a mark having a color or shape different from that of the first side surface on a side surface different from the first side surface. By providing a plurality of marks, the possibility that one of the marks will appear in the connector image is increased, so that the possibility of measurement is increased. Further, for example, by providing marks having different colors and shapes on the front surface and the back surface of the connector, the orientation of the connector can be easily recognized.

Further, for example, in the second embodiment, the three-dimensional information of the vertical side can be used. In the second embodiment, the mark 42 does not have to be in contact with the vertical side, and the orientation and position of the entire connector can be determined based only on the three-dimensional measurement result of the mark 42. However, when the mark 42 is in contact with the vertical side (for example, FIGS. 13A to 13F), or when the mark 42 is not in contact with the vertical side but the orientation of the vertical side can be detected by the shape of the mark (for example, FIG. 16B). -E, FIGS. 19C to D), and the three-dimensional measurement results of the mark 42, the three-dimensional information of the vertical side of the contour may be used as in the first embodiment.

The present invention can also be applied to recognize the position and orientation of a connector that is not connected to a cable. In this case, since the vertical side of the connector cannot be determined from the direction of the cable, instead, the vertical side of the connector can be determined from the direction of the mark registered in advance. After recognizing the position and orientation of the connector, it is also possible to grasp the connector with, for example, a robot hand and connect it to the cable.

10 Connector 11 Bottom surface 12 flange 13 Rear edge 14 Side surface 15 First side surface 16 Vertical side 17 Reference vertical side 19 Tip 20 Insertion part 21 Concave groove 22 Connection hole 23 Terminal insertion port 25 Mating connector 26 pin 30 Mark 31 First end point 32 2nd end point 35 Cable 40, 41 Connector 42 Mark 50 Robot 51 Robot hand 52 Grip part 53 V-shaped groove 54 Robot control part 55 Stereo camera (three-dimensional measuring device)
56 Camera 57 Stereo camera control unit

Claims (11)

It has a substantially prismatic shape having a plurality of side surfaces and a plurality of vertical sides serving as boundaries between the adjacent side surfaces, with the surface connected to the tip of the cable and from which the cable is pulled out as the bottom surface. An image acquisition process of acquiring a connector image by imaging a connector having a mark on the first side surface with a three-dimensional measuring device, which is one of the above.
A recognition process for recognizing the mark from the connector image and
A three-dimensional measurement process that calculates the orientation and position of the connector based on the recognized mark.
A three-dimensional measurement method for a connector having. The three-dimensional measuring device is a stereo camera.
The three-dimensional measurement method for a connector according to claim 1. The mark is a linear mark that crosses the first side surface.
In the recognition step, one reference vertical side that constitutes the contour of the connector and is in contact with the mark is further recognized from the connector image.
The three-dimensional measurement step calculates the orientation and position of the connector based on the three-dimensional measurement results of at least three points on the reference vertical side or on the mark but not on a straight line.
The three-dimensional measurement method for a connector according to claim 1 or 2. The mark consists of a set of points having one or more points on each of the two vertical sides at both ends of the first side surface.
In the recognition step, one reference vertical side that constitutes the contour of the connector and is in contact with the mark is further recognized from the connector image.
The three-dimensional measurement step calculates the orientation and position of the connector based on the reference vertical side and the mark.
The three-dimensional measurement method for a connector according to claim 1 or 2. The mark is a mark that occupies a certain area on the first side surface.
The three-dimensional measurement method for a connector according to claim 1 or 2. The connector has a substantially rectangular parallelepiped shape.
The three-dimensional measurement method for a connector according to any one of claims 1 to 5. The first side surface is the widest side surface of the side surfaces of the connector.
The three-dimensional measurement method for a connector according to any one of claims 1 to 6. A step of performing three-dimensional measurement of the connector by using the three-dimensional measurement method according to any one of claims 1 to 7.
A gripping position calculation step of calculating a gripping position when gripping the connector with a robot hand based on the three-dimensional measurement result of the connector, and
A method for calculating the gripping position of a connector having. After carrying out the method for calculating the gripping position of the connector according to claim 8, further comprising a gripping step of gripping the gripping position with a robot hand.
How to grip the connector. After the method of gripping the connector according to claim 9, the robot hand grips the connector, and the robot hand is operated to connect the connector to the other party connector.
How to connect the connector. It has a substantially prismatic shape with the surface from which the connected cable is pulled out as the bottom surface.
A mark for three-dimensional measurement is provided on the first side surface, which is one of the side surfaces adjacent to the bottom surface.
connector.

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