Linear object insertion method, control device, and linear object hole insertion system

Abstract

To provide a method for inserting a linear object in which a robot hand holds a curved linear object and inserting it into a hole.SOLUTION: A method for inserting a linear object includes the steps of: holding a tube T by a robot hand 12; inserting a tip of a tube T into a hole H; and after the insertion of the tip of the tube T, pushing the tube T into the hole H so that a direction of a held part of the tube T can substantially correspond to a central axis C of the hole H and so that a distance from the center C0 of the hole H to the held part of the tube T can be a predetermined distance Z.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a linear object insertion method for grasping a curved linear object with a robot hand and inserting it into a hole, a control device used in the insertion method, a three-dimensional camera, and a linear object hole insertion system. [Background technology]

[0002] In recent years, various tasks have been performed using robotic hands. Techniques for manipulating linear objects in such tasks using robotic hands have been disclosed. For example, Patent Document 1 discloses a technique in which a robot device grasps the tip of a cable and connects it to a connector. The present applicant has proposed a method for determining a target linear object to be grasped by a robot hand from among a plurality of linear objects, as disclosed in Patent Document 2. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-176917 [Patent Document 2] WO2019 / 098074 Summary of the Invention [Problem to be solved by the invention]

[0004] The present applicant has also proposed a method for grasping a linear object of interest from among multiple linear objects and moving the tip of the linear object to a hole (target position), as disclosed in Japanese Patent Application No. 2018-31263. However, a new problem was discovered: when the linear object is curved, simply moving the tip of the linear object to the hole (target position) does not result in smooth insertion of the linear object into the hole. Specifically, when pushing the linear object into the hole while maintaining the robot hand's posture at the target position, the robot hand collides with the edge of the hole's opening, preventing the linear object from being pushed deep enough to reach the position where the robot hand is grasping it. Furthermore, while the robot hand is pushing the curved linear object, it may get caught in the hole, preventing the linear object from being pushed deep into the hole. Thus, the present invention aims to provide a method for inserting a linear object, in which the linear object is grasped by a robot hand, the tip of the linear object is moved to a predetermined position, and then a part of the linear object is inserted into a hole, as well as a control device, a three-dimensional camera, and a system for inserting a linear object into a hole, which are used in this insertion method. [Means for solving the problem]

[0005] The method for inserting a linear object of the present invention is a method for inserting a linear object in which a curved linear object is grasped by a robot hand and inserted into a hole, and is characterized by comprising the steps of: grasping the linear object with a grasping portion of the robot hand; inserting the tip of the linear object into the hole; and, after inserting the tip, pushing the linear object into the hole so that the orientation of the grasped portion of the linear object substantially coincides with the central axis of the hole and so that the grasped portion is a predetermined distance from the center of the hole. In the method for inserting a linear object of the present invention, after inserting the tip of the linear object, the robot hand is moved to push the linear object into the hole so that the orientation of the gripped part of the linear object is substantially aligned with the central axis of the hole and so that the gripped part is a predetermined distance from the center of the hole, thereby enabling the linear object to be reliably inserted up to the vicinity of the part gripped by the robot hand.

[0006] The method for inserting a linear object of the present invention preferably further comprises a step of acquiring position and orientation information of the tip of the linear object after the gripping step. If the linear object is flexible, the curved shape of the linear object may change when gripped by the robot hand. By acquiring position and orientation information of the tip of the linear object after gripping, the linear object can be reliably inserted into the hole even if the curved shape of the linear object changes. In the method for inserting a linear object of the present invention, the step of inserting the tip of the linear object into the hole is preferably a step of inserting the tip of the linear object so that the direction of the tip of the linear object substantially coincides with the central axis of the hole, in which case the tip of the linear object can be reliably inserted into the hole. In the method for inserting a linear object according to the present invention, the robot hand includes a gripping portion of the robot hand. Orientation of the fingers and the gripped portion of the linear object. Orientation It is preferable that the linear object is grasped so that the gripping portion of the robot hand is approximately perpendicular to the linear object. Orientation of the fingers It is preferable that the linear object is pushed into the hole so that the axis of the linear object is approximately perpendicular to the central axis of the hole.

[0007] In the method for inserting a linear object of the present invention, the linear object is transparent, and the step of gripping the linear object by the robot hand preferably includes a step of acquiring a three-dimensional shape of the linear object from an image of the linear object captured in front light against a dark background, or a step of acquiring the three-dimensional shape of the linear object from an image of the linear object captured in back light, and the robot hand grips the linear object based on the three-dimensional shape of the linear object. In this case, the shape of the linear object can be clearly captured by a camera or the like, and a detailed three-dimensional shape of the linear object can be acquired.

[0008] The method for inserting a linear object according to the present invention is suitable for a flexible linear object, and is particularly suitable for a resin tube.

[0009] The control device of the present invention is a control device for controlling a robot used to grasp a curved linear object with a robot hand and insert it into a hole, and is characterized in that it notifies the robot of information for grasping the linear object, information for inserting the tip of the linear object into the hole, and information for pushing the linear object into the hole so that the orientation of the grasped portion of the linear object substantially coincides with the central axis of the hole and so that the grasped portion of the linear object is a predetermined distance from the center of the hole. Note that the notification of the information for pushing the linear object into the hole may be before or after inserting the tip of the linear object into the hole.

[0010] The three-dimensional camera of the present invention is a three-dimensional camera used to control the operation of a robot that grasps a curved linear object with a robot hand and inserts it into a hole, and the three-dimensional camera includes a camera control device that acquires the three-dimensional shape of the linear object from an image captured by the three-dimensional camera, and based on the three-dimensional shape, notifies the robot of information for inserting the tip of the linear object into the hole, and based on the three-dimensional shape, notifies the robot of information for pushing the linear object into the hole so that the orientation of the grasped portion of the linear object substantially coincides with the central axis of the hole and so that the grasped portion of the linear object is a predetermined distance from the center of the hole.

[0011] The system for inserting a linear object into a hole of the present invention is characterized by having the three-dimensional camera of the present invention and a robot equipped with a robot hand that grasps the linear object. A second aspect of the linear object hole insertion system of the present invention is characterized by having a robot equipped with a robot hand that grasps a linear object, a three-dimensional measuring device, and the control device of the present invention. [Effects of the Invention]

[0012] According to the present invention, even if the linear object is curved, it can be reliably inserted into the hole and pushed all the way to the back of the hole, thereby simplifying the complicated insertion work of the curved linear object. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a schematic diagram showing a linear object hole insertion system for carrying out the linear object insertion method of the present invention. [Figure 2] 1 is a flow chart showing an embodiment of a method for inserting a linear object according to the present invention. [Figure 3] Figure 3a is a schematic diagram showing the state just before the tube is grasped by the robot hand, Figure 3b is a schematic diagram showing the state just after the tube is grasped by the robot hand, and Figure 3c is a schematic diagram showing the tube grasped by the robot hand at a second imaging position. [Figure 4] FIG. 4a is a schematic diagram of the robot hand when it is moved to the pre-insertion position, and FIG. 4b is a schematic diagram of the robot hand when it is moved to the insertion position. [Figure 5] FIG. 5a is a schematic diagram of the robot hand when it is moved to the insertion completion position, and FIG. 5b is a schematic diagram showing the trajectory of the robot hand. DETAILED DESCRIPTION OF THE INVENTION

[0014] Fig. 1 shows a system 1 for inserting a linear object into a hole for carrying out a method for inserting a tube T (linear object). The system 1 for inserting a linear object into a hole includes a robot 10 having a robot hand 12, a three-dimensional measuring device (three-dimensional camera) 20, and a control device 30. In the working space, a storage cylinder S in which the tube T is stored and a hole H into which the tube T is inserted are arranged. The tip of the tube T is inserted into the storage cylinder S so that it protrudes. In this linear object hole insertion system 1, a curved tube T stored in a storage cylinder S is grasped by a robot hand 12, removed from the storage cylinder S, and inserted into a hole H.

[0015] First, the tube T will be explained. The tube T is a flexible, transparent resin tube. Here, flexibility means that when the tube T is grasped by a robotic hand or the like, it bends elastically from the grasping position to the tip due to its own weight. In other words, the axis of the tube T, which is bending due to its own weight, can be represented as a continuous curve bent in one direction on a vertical plane. Here, "transparent" includes translucency, and preferred materials for transparent tubes include transparent resins such as nylon, polyamide, acrylic, polypropylene, and polyvinyl chloride, as well as glass, polyamide elastomer, silicone, and Teflon (registered trademark). However, opaque tubes are also acceptable. Examples of such opaque tubes include industrial tubes. Flexible linear objects other than tubes may also be used. Examples of flexible linear objects other than tubes include electric wires, wire harnesses, strings, threads, fibers, glass fibers, optical fibers, and dried noodles. The diameter of the tube T is, for example, 0.1 mm to 3 mm, preferably 0.15 mm to 2 mm, particularly good Preferably, it is 0.2 mm to 1 mm.

[0016] The storage cylinder S is for inserting and storing the tube T. When the tube T is inserted, it is long enough that a portion of the tube T protrudes. The storage cylinder S is fixed within the work space. Note that the tube T does not necessarily have to be stored in the storage cylinder, and may be placed on a workbench or the like. It is preferable that the portion of the tube T that is to be held protrudes from the storage cylinder, or that the portion that is to be held is not in contact with the ground, as this makes it easier for the robot hand to hold it. The hole H is circular and its inner surface is cylindrical. The hole H is fixed within the working space and opens horizontally. The hole H may have a tapered structure. The effects of the present invention are more pronounced when the hole H has a tapered structure in which the diameter decreases from the opening surface toward the back. If the clearance of the hole relative to the tube is small, it is possible to apply the present invention by providing a tapered insertion aid in front of the hole, essentially widening the diameter of the opening of the hole. The orientation of the hole H is not particularly limited. The diameter of the hole H is preferably 0.5 mm or more and 10 mm or less than the diameter of the tube to be inserted. If the diameter of the hole H is greater than the diameter of the tube plus 10 mm, the tube is less likely to get caught midway through the hole during the pushing operation, hindering insertion, and there is less need to apply the present invention. The hole H does not have to be circular. In that case, the diameter of the inscribed circle of the hole H is the diameter of the hole as referred to in this specification.

[0017] Next, the linear object hole insertion system 1 will be described. The robot 10 has an articulated arm 11 and a robot hand 12 attached to the tip thereof, and the robot hand 12 is a known robot hand equipped with a pair of fingers (gripping portions) 12a. There are no particular limitations on the type of fingers 12a, and examples include fingers that grip a tube (linear object) T by contacting it in a planar or linear manner, or fingers that grip it at a point.

[0018] The three-dimensional measuring device 20 is a stereo camera having a first camera 21, a second camera 22, and a camera control unit 23. The first camera 21 is a color camera that captures a first image, which is a two-dimensional color image, and the second camera 22 is a color camera that captures a second image, which is a two-dimensional color image. The first camera 21 and the second camera 22 are fixed at different positions. The camera control unit 23 controls the first camera 21 and the second camera 22 to calculate the three-dimensional shape of the tube T and communicates with the control device 30. More specifically, the camera control unit 23 receives an image capture instruction from the control device 30 and instructs the first camera 21 and the second camera 22 to capture images, calculates the three-dimensional shape of the tube T from the first image and the second image, and transmits the three-dimensional shape to the control device 30. It is preferable that the first and second images are taken at the imaging position of the tube T in the work space by imaging the reflected light of the tube T in front light with a dark background, or by imaging the tube T in back light using transmitted illumination, and then a silhouette image of the tube T is obtained and the three-dimensional shape is calculated. By imaging in this manner, even if the tube T is transparent, the difference in brightness between the tube T and the background in the image obtained by imaging is large, so the shape of the tube T can be clearly exposed and the three-dimensional shape of the tube T can be obtained more accurately. Note that front lighting means a state in which light is irradiated onto the tube T from the camera side, and back lighting means a state in which light is irradiated onto the tube T from behind. The method for calculating three-dimensional shapes using a stereo camera involves determining the measurement point to be measured from the first image from the first camera and the second image from the second camera, and then calculating the three-dimensional coordinates of the measurement point using the principle of triangulation based on the relative positions of the first and second cameras. The three-dimensional measuring device 20 is not limited to a stereo camera, and a three-dimensional scanner or the like may be used as long as it can acquire the three-dimensional shape of a linear object. Furthermore, it is not necessary to calculate the three-dimensional shape of the entire linear object; it is sufficient to be able to calculate at least the position and orientation of the part of the linear object that is grasped by the robot hand and the position and orientation of the tip of the side that is inserted into the hole.

[0019] The control device 30 communicates with the three-dimensional measuring device 20, instructs the robot 10 based on the three-dimensional shape of the tube T acquired from the three-dimensional measuring device 20, and performs various calculations. The control device 30 may be a control device independent of the robot 10 and the three-dimensional measuring device 20, or may be a camera control unit 23 provided in the three-dimensional measuring device 20, or a robot control device provided in the robot 10. The positions of the storage tube S and the hole H are registered in advance in the control device 30.

[0020] Next, a method for inserting a linear object, in which the tube T of the storage cylinder S is taken out by the robot hand 12 and inserted into the hole H, will be described with reference to FIG. The method for inserting a linear object includes step 1 of imaging the tube T to obtain the three-dimensional shape of the tube T, step 2 of calculating the position of the grasped portion G of the tube T, step 3 of calculating the grasping posture and grasping position of the robot hand 12, step 4 of grasping the tube T with the robot hand, step 5 of moving the tube T to a second imaging position, step 6 of imaging the tube T in the grasped state at the second imaging position to obtain the three-dimensional shape of the tube T, step 7 of calculating the position and orientation of the tip E of the tube T (insertion portion I) in the grasped state, step 8 of moving the robot hand to a pre-insertion position, step 9 of moving the robot hand to the insertion position, and step 10 of pushing the tube T into the hole H and moving the robot hand to the insertion completion position.

[0021] The tube T is imaged to obtain the three-dimensional shape of the tube T (step 1). In step 1, the above-mentioned three-dimensional measuring device 20 measures the tube T protruding from the cylindrical storage S at a first imaging position and calculates its three-dimensional shape. Specifically, a stereo camera captures images of the workspace in which the cylindrical storage S with the tube T inserted is located, and the two images are processed to obtain the three-dimensional shape of the tube T protruding from the cylindrical storage S. The three-dimensional shape of the tube T is represented by a Cartesian coordinate system or an oblique coordinate system, and is preferably represented by a Cartesian coordinate system.

[0022] The position of the part G of the tube T that is grasped by the robot hand is calculated (step 2). In step 2, as shown in Figure 3a, the portion G of the tube T to be grasped by the robot hand is determined from the three-dimensional shape of the tube T based on predetermined conditions, such as defining a predetermined length X from the tip of the tube T as the portion G to be grasped by the robot hand, and the position (coordinates) of the grasped portion G is obtained. The length X of the insertion portion I from the tip E to the gripped portion G is 10 mm to 100 mm, preferably 15 mm to 90 mm, and particularly preferably 20 mm to 80 mm. In this insertion method, the insertion portion I of the tube T is inserted. If the length X is longer than 100 mm, the bending of the insertion portion I becomes too great, which may prevent the pushing step in step 10 from being performed.

[0023] The grasping posture and grasping position of the robot hand 12 are calculated (step 3). 3a and 3b, the gripping posture of the robot hand is preferably such that when the robot hand 12 grips the gripped portion G of the tube T, the orientation F1 of the fingers 12a of the robot hand 12 and the orientation D1 of the gripped portion G of the tube T are approximately perpendicular. This is because, in the step of pushing the linear object described below, the fingers 12a are less likely to interfere with the hole H, and by making the orientation F1 of the fingers approximately perpendicular to the central axis of the hole, the linear object can be pushed deeper into the hole. The gripping direction of the robot hand may be from any direction within 360 degrees around the axis of the gripped portion G of the tube T. However, it is preferable that the robot hand 12 be positioned on the convex side of the curved tube T. In particular, it is preferable that the robot hand 12 be positioned on the convex side of the tube T so as to be parallel to a vertical plane Sp that includes the axis T0 of the curved tube T. Here, "the robot hand 12 being parallel to the vertical plane Sp" means that the contact surfaces of the pair of fingers 12a are parallel to the vertical plane Sp and the centers of the pair of fingers 12a are on that vertical plane. This is the preferable posture when the robot hand 12 approaches the curved tube T from the convex side and grips the gripped portion G of the tube T with the pair of fingers 12a. The orientation F1 of the fingers 12a of the robot hand 12 refers to the orientation of the tips of the fingers 12a or the orientation of a plane including a pair of fingers 12a (the plane in the direction of the paper including symbol F1 in Figure 3a), and in particular refers to the orientation in which the fingers 12a approach the tube T when grasping the tube T. The direction D1 of the portion G grasped by the robot hand is calculated by determining the average vector of a line segment L1 of the portion grasped by the fingers 12a from the three-dimensional shape of the tube T. The length of the line segment L1 can be set to a predetermined length, such as the length of the thickness of the fingers 12a centered on the position where the tube T is grasped.

[0024] In this way, the gripping position and gripping posture of the robot hand 12 are the coordinates and posture of the robot hand 12 when the robot hand 12 grips the gripping part G, as shown in FIG. 3b. Then, by having the robot hand 12 grasp the tube T with the direction F1 of the fingers 12a and the direction D1 of the grasped portion G being approximately perpendicular, the tube T can be firmly inserted into the hole all the way to the back of the insertion part I (just before the grasped portion G) in step 10, as will be described later. Also, by positioning the robot hand 12 on the convex side of the tube on the vertical plane and making it parallel to the vertical plane, it is possible for the robot hand to grasp the tube T at the grasping position without interfering with the bent tip portion of the tube T, etc.

[0025] The tube T is grasped by the robot hand 12 (step 4). In step 4, the robot hand 12 is moved from the standby position to the gripping position, and grips the portion G of the tube T at the gripping position. The standby position of the robot hand 12 is not particularly limited and may be determined in advance. For example, it may be determined based on the three-dimensional shape of the tube T, such as a position a predetermined distance away from the tube T in the opposite direction to the gripping direction (for example, the position of the robot hand 12 in FIG. 3a). However, the coordinates and posture of the standby position may be determined in advance and registered in the control device, for example, based on the angle of each link of the robot. When gripping the same type of tube multiple times, the way the tube bends is similar, so if the first gripping position and gripping posture are registered in advance, it is often possible to grip subsequent tubes of the same type at the same gripping position and gripping posture. The trajectory of the robot hand 12 from the standby position to the gripping position is not particularly limited. The robot hand 12 is caused to approach the part G to be gripped so as not to come into contact with obstacles such as the storage cylinder S. The trajectory can be calculated by means of gradually moving the robot hand 12 toward the destination, such as linear interpolation, which calculates a trajectory from the standby position to the gripping position that is a straight line; circular interpolation, which calculates a trajectory from the standby position to the gripping position that is an arc; or joint interpolation, which calculates a trajectory by uniformly interpolating the joint angle differences of each link at the standby position and the gripping position.

[0026] The tube T is moved to the second imaging position (step 5). The second imaging position of the robot hand is a position where an image of the tube T gripped by the robot hand 12 is taken in step 6. The coordinates of this second imaging position are not particularly limited, but may be a position between the storage cylinder S and the hole H, a position where the tube T has been completely removed from the storage cylinder S, or a position where the tube T has not yet been completely removed from the storage cylinder S. For example, by including the first imaging position in step 1 and the second imaging position in step 5 within the imaging range of one three-dimensional measuring device 20, it is possible to obtain images of both the tube T before and after being gripped by one three-dimensional measuring device 20, which is preferable. It is preferable that the second image capturing position (coordinates and posture) of the robot hand 12 is determined in advance and registered in the control device, for example, based on the angle of each link of the robot.

[0027] The three-dimensional shape of the tube T in the gripped state is acquired (step 6). In step 6, the tube T in a grasped state is imaged by the three-dimensional measuring device 20 at the second imaging position, as in step 1, and the three-dimensional shape of the grasped tube T is calculated from the image. This makes it possible to obtain a detailed three-dimensional shape of the tube T (insertion portion I) in a grasped state immediately before insertion. That is, because the tube T is flexible as described above, the three-dimensional shape of the tube T when grasped by the robot hand may differ from the three-dimensional shape of the tube T when stored in the storage tube S (e.g., Figures 3b and 3c). Therefore, the tube T is placed at the second imaging position, and the three-dimensional shape of the tube T in a grasped state is calculated again. However, if the tube T is somewhat rigid and the position of the tip of the tube T does not substantially change, steps 5 to 7 may be omitted, and the three-dimensional shape of the tube T in step 1 may be treated as the three-dimensional shape of the insertion portion I of the tube T in a grasped state. The three-dimensional shape of the insertion portion I is also preferably represented in a Cartesian coordinate system.

[0028] The position and orientation of the tip E of the tube T (insertion part I) in the grasped state are calculated (step 7). The position of the tip E is determined by calculating the coordinates of the tip E based on the three-dimensional shape of the insertion portion I. Also, for example, since the tube T is curved in one direction, the distance from the grasped portion G may be measured. The direction D2 of the tip E of the tube T is calculated by determining the average vector of a line segment L2 having a predetermined length (for example, about 10 mm) from the tip E based on the three-dimensional shape of the insertion portion I.

[0029] The robot hand is moved to a position just before insertion (step 8). In step 8, the pre-insertion position of the robot hand is calculated, and the robot hand 12 is moved from the second imaging position to the pre-insertion position. The pre-insertion position of the robot hand can be set anywhere near the hole, but preferably, as shown in Figure 4a, it is the position (coordinates and posture) of the robot hand when the robot hand is gripping the tube T, the orientation D2 of the tip E of the tube T is approximately horizontal (substantially aligned with the central axis C of the hole H), and the tip E of the tube T is at a predetermined distance Y from the center C0 of the hole H. The angles of each link of the robot when this state is reached are calculated. When the robot hand 12 is in the pre-insertion position, the coordinates of the tip E of the tube T are preferably near the hole H. For example, the distance Y between the tip E of the tube T and the center C0 of the hole H is 5 to 100 mm, preferably 7 mm to 70 mm, and particularly preferably 10 to 50 mm. The trajectory from the second imaging position to the pre-insertion position is not particularly limited, and is preferably calculated by linear interpolation, circular interpolation, joint interpolation, or the like.

[0030] The robot hand 12 is moved to the insertion position (step 9). In step 9, the insertion position of the robot hand is calculated, and the robot hand 12 is moved from the pre-insertion position to the insertion position. 4b, the insertion position of the robot hand 12 is the position (coordinates and posture) of the robot hand when the robot hand is gripping the tube T, the orientation of the tip E of the tube T coincides with the central axis C of the hole H, and the tip E of the tube T is inside the hole H. Here, the distance Y1 between the tip E and the center C0 of the hole H is 0 to 20 mm, preferably 1 to 15 mm, and particularly preferably 2 to 10 mm. The distance Y1 from the center C0 of the hole H of the tip E at the insertion position is selected appropriately depending on the curvature of the tube T to be handled and the clearance of the tube T from the hole H. That is, at the position before insertion in step 8 (FIG. 4a), the direction D2 of the tip E of the tube T substantially coincides with the central axis C of the hole H, and the tip E of the tube T is at a predetermined distance Y from the center C0 of the hole H, so in step 9, the tube T is translated until the tip of the tube T, which is at the predetermined distance Y from the center C0 of the hole H, is inserted into the hole H. This allows the tip of the tube T to be inserted straight into the hole. By moving the robot hand 12 to the insertion position in this manner, at least the tip E of the tube T is inserted into the hole H.

[0031] While pushing the tube T into the hole, the robot hand 12 is moved to the insertion completion position (step 10). In step 10, the insertion completion position of the robot hand 12 is calculated, and the robot hand 12 is moved from the insertion position to the insertion completion position while pushing the tube T into the hole, thereby completing the insertion of the tube T. 5a, the insertion completion position of the robot hand is the position (coordinates and posture) of the robot hand when the robot hand is gripping the tube T substantially vertically, the fingers 12a of the robot hand are substantially perpendicular to the central axis C of the hole H, and the distance Z is between the center O of the fingers 12a of the robot hand (the center of the gripped portion G of the tube T) and the center C0 of the hole H. Note that since this insertion completion position of the robot hand is determined by the relationship between the robot hand and the hole H, it is preferable to determine the coordinates and imaging posture in advance and register them in the control device, for example, based on the angle of each link of the robot.

[0032] When the robot hand is not holding the tube T substantially vertically, the insertion completion position is the position (coordinates and posture) of the robot hand when the orientation D1 of the held portion G of the tube T substantially coincides with the central axis C of the hole H and the held portion G is at a predetermined distance from the center of the hole H. ofThe orientation of the gripped portion of the tube T can be obtained from the three-dimensional shape and the robot's tube gripping direction. The orientation of the robot hand at the insertion completion position (the orientation F1 of the robot hand's fingers) can be calculated from the orientation of the gripped portion of the tube and the gripping posture of the robot hand. By moving the robot hand 12 to the insertion completion position in this way, even if the insertion portion I of the tube T is curved, it will not get caught in the middle of the hole, and substantially the entire inserted portion of the tube T will be pushed into the hole.

[0033] The insertion completion position of the robot hand can be, for example, a position where the distance Z between the center O of the fingers 12a of the robot hand (the center of the gripped portion G of the tube T) and the center C0 of the hole H is greater than 0 and not greater than 50 mm, preferably greater than 0 and not greater than 20 mm, and particularly preferably greater than 0 and not greater than 10 mm. Note that if the distance Z between the center O of the fingers 12a of the robot hand and the center C0 of the hole H is 0, the fingers 12a and the hole H will come into contact, which is not practical. If the distance Z between the fingers 12a of the robot hand and the hole H is greater than 50 mm, the effect of bending of the tube T will be unnecessarily large in the handling operation of the tube T from the gripping process to the completion of insertion.

[0034] The trajectory of the robot from the insertion position to the insertion completion position is not particularly limited and can be calculated using linear interpolation, circular interpolation, or joint interpolation, as described above. Joint interpolation is particularly preferable. That is, the joint angles of each link of the robot at the insertion position and the joint angles of each link of the robot at the insertion completion position are obtained, the joint angle difference between each link is calculated, and the trajectory is determined by interpolating these. This allows the robot hand 12 to move to the insertion completion position while gradually approaching the opening of the hole H so as to follow the curved shape of the tube T, as shown in FIG. 5b. In other words, the trajectory can be made to follow a trajectory that closely resembles the curved shape of the tube T, making it less likely for the tube T to break or get stuck in the hole H. However, the trajectory of the robot hand 12 may also be calculated by approximating the path from the robot's insertion position to the insertion completion position as an arc and using circular interpolation to follow the arc as the trajectory. While this requires more complex calculations than joint interpolation, it allows the robot hand 12 to move along the curved shape of the tube T, making it less likely for the tube T to break during the pushing process, which is preferable when the tube T is very soft. In this way, by moving the robot hand 12 from the insertion position so that the orientation D1 of the gripped portion of the tube T at the completed insertion position substantially coincides with the central axis C of the hole H, the insertion portion I of the tube T inserted into the hole is guided by the hole H to become approximately straight and is reliably inserted up to the vicinity of the gripped portion G.

[0035] As described above, the method of inserting a linear object in Figure 2 simplifies the insertion operation of the tube T because the robot hand is moved to a position just before insertion. Also, because the robot hand is moved to the insertion position, the tip E of the tube T can be reliably inserted into the hole H. And, because the robot hand is moved to the insertion completion position, the robot hand can be inserted all the way to the base end of the insertion section I (the portion G of the tube T that is gripped) without coming into contact with the hole.

[0036] 2, when multiple tubes T of the same material and shape are inserted, the curvature of these tubes T will be substantially the same. In this case, the second imaging position of the robot, the position before insertion of the robot, the insertion position of the robot hand, and the trajectory of the robot hand may be memorized in advance in the control device 30. By teaching the insertion position and the insertion completion position to the robot hand in advance in this way, it is possible to omit the calculations in steps 5 to 8 in the subsequent method of inserting a linear object. In this case, the robot hand also moves to the insertion completion position, and therefore the same effects as those of the above embodiment can be achieved.

[0037] In the above embodiment, the robot hand is moved to the pre-insertion position, but it may be moved directly from the gripping position or the second imaging position to the insertion position without passing through the pre-insertion position. In other words, step 8 may be omitted.

[0038] In the above embodiment, one tube T stored in the storage cylinder S is grasped and inserted into the hole H, but a tube T placed on the ground or the like may be grasped and inserted into the hole H. Also, one tube may be selected from multiple tubes T, grasped, and inserted into the hole H. As a method for grasping one of multiple linear objects, for example, as shown in Patent Document 2, a linear object of interest may be determined and grasped. Multiple tubes T may be inserted into the storage cylinder S, and the linear object of interest may be determined.

[0039] In the above embodiment, the target is a flexible linear object, but as long as the insertion portion of the linear object is non-linear, it may be a hard linear object that does not have flexibility. In this case, if the three-dimensional shape of the tube T is acquired first, it is not necessary to acquire the three-dimensional shape of the insertion portion (steps 5 to 7 are omitted). Furthermore, although the tube in the above embodiment is curved in one direction due to its own weight, it can also be used for linear objects that have an inherent bending tendency.

[0040] In the above embodiment, this is not a problem because the tube T (linear object) has a certain degree of hardness or elasticity, or the distance from the tip of the tube T to the grasped portion G is short and the deflection is small. However, if the linear object is very soft, it is preferable to make the orientation of the grasped portion G at the second imaging position of the robot hand in step 5 substantially the same as the orientation of the grasped portion G at the insertion position of the robot hand in step 9. In other words, the curvature (degree of deflection) of the linear object (tube T) varies depending on the orientation of the grasped portion G of the tube T. More specifically, when the grasped portion G of the linear object (tube T) faces upward, the deflection is large, and when it faces downward, the deflection is small. Therefore, if the orientation of the grasped portion G at the second imaging position of the robot hand in step 5 differs from the orientation of the grasped portion G at the insertion position of the robot hand in step 9, the deflected shape (degree of curvature) of the linear object will differ. As a result, the position and orientation of the tip of the linear object based on the image captured at the second imaging position in step 5 (step 7) will not allow insertion in step 9. In this way, by making the orientation of the gripped portion G at the second imaging position of the robot hand substantially the same as the orientation of the gripped portion G at the insertion position of the robot hand in step 9, even a very soft linear object can be accurately inserted into the hole. The orientation of the robot hand at the second imaging position in step 5 can be determined, for example, by registering an appropriate orientation in advance using a sample tube, or by having the robot hand memorize the orientation of the previous linear object grasped in step 9. [Explanation of symbols]

[0041] 1. Linear object hole insertion system 10. Robot 11 Articulated Arm 12 Robot Hand 12a Finger 20 Three-dimensional measuring device 21 Camera 1 22 Second Camera 23 Camera control unit 30 Control device C: Hole central axis E. The tip of the tube (insertion part) in a grasped state G Gripped part H hole I Insertion section S storage tube Sp vertical plane T-tube

Claims

1. A method for inserting a linear object by gripping a curved linear object with a robot hand and inserting the curved linear object into a hole, comprising: a step of gripping the linear object with a gripping portion of the robot hand; a step of acquiring, by three-dimensional measurement, position and orientation information of the tip of the linear object, which is curved beyond the portion gripped by the gripping unit; moving the robot hand to a pre-insertion position where the direction of the tip of the linear object substantially coincides with the central axis of the hole and the tip of the linear object is a predetermined distance from the center of the hole; a step of moving the robot hand from the pre-insertion position to an insertion position by moving the linear object in parallel toward the hole, and inserting the tip of the linear object into the hole so that the direction of the tip of the linear object substantially coincides with the central axis of the hole; and after inserting the tip, pushing the linear object into the hole by changing the direction of the robot hand and moving it from the insertion position to an insertion completion position so that the direction of the gripped portion of the linear object substantially coincides with the central axis of the hole and so that the gripped portion is a predetermined distance from the center of the hole. How to insert a linear object.

2. the robot hand grasps the linear object so that a direction of a finger provided in a gripping unit of the robot hand and a direction of a gripped portion of the linear object are approximately perpendicular to each other; The method for inserting a linear object according to claim 1.

3. The linear object is transparent, The step of gripping the linear object by the robot hand includes: acquiring a three-dimensional shape of the linear object from an image of the linear object captured in front light with a dark background; the robot hand grasps the linear object based on the three-dimensional shape of the linear object; The method for inserting a linear object according to claim 1 or 2.

4. The linear object is transparent, The step of gripping the linear object by the robot hand includes: acquiring a three-dimensional shape of the linear object from an image of the linear object captured against light, the robot hand grasps the linear object based on the three-dimensional shape of the linear object; The method for inserting a linear object according to claim 1 or 2.

5. The linear object has flexibility. The method for inserting a linear object according to any one of claims 1 to 4.

6. The linear object is a resin tube. The method for inserting a linear object according to claim 5.

7. A control device for controlling a robot used to grip a curved linear object with a robot hand and insert it into a hole, instructing a three-dimensional measuring device to measure the linear object, receiving from the three-dimensional measuring device the position and orientation of the portion of the linear object to be grasped, and notifying the robot of information for grasping the linear object; after the robot has grasped the linear object, instruct the three-dimensional measuring device to measure the linear object, which is curved beyond the portion grasped by the robot hand; receive the position and orientation of the tip of the linear object from the three-dimensional measuring device; and notify the robot of information for moving the robot hand to a pre-insertion position where the orientation of the tip of the linear object substantially coincides with the central axis of the hole and where the tip of the linear object is a predetermined distance from the center of the hole, and information for moving the robot hand from the pre-insertion position to an insertion position by moving the linear object parallel to the hole, and inserting the tip of the linear object into the hole so that the orientation of the tip of the linear object substantially coincides with the central axis of the hole; the robot hand changes direction and moves from the insertion position to an insertion completion position so that the orientation of the gripped portion of the linear object substantially coincides with the central axis of the hole and so that the gripped portion of the linear object is a predetermined distance from the center of the hole, thereby notifying the robot of information for pushing the linear object into the hole. Control device.

8. A system comprising the control device according to claim 7, the robot, and the three-dimensional measuring device. Linear object hole insertion system.

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