阅读说明：本技术 线状物的前端移动方法、控制装置以及三维照相机 (Method for moving tip of linear object, control device, and three-dimensional camera ) 是由 北井基善 于 2019-02-15 设计创作，主要内容包括：一种线状物的前端移动方法,所述线状物的前端移动方法是使由机械手(22)握持的线状物(W1)的前端(W1s)移动至目标位置(TG1)时的线状物的前端移动方法,包括：对由机械手(22)握持的线状物(W1)的前端(W1s)的位置进行测量的步骤；以及基于测量到的前端(W1s)的位置,使前端(W1s)移动至目标位置(TG1)的步骤。(A method for moving a wire tip, which is used when moving a wire tip (W1s) of a wire (W1) held by a robot (22) to a target position (TG1), comprising: a step of measuring the position of the tip (W1s) of a wire (W1) held by a robot (22); and a step of moving the leading end (W1s) to the target position (TG1) based on the measured position of the leading end (W1 s).)

1. A method for moving the tip of a linear object when the tip of the linear object held by a robot is moved to a target position, comprising:

a step of measuring a position of the tip of the linear object held by the manipulator; and

moving the front end to the target position, the front end being moved to the target position based on the measured position of the front end.

2. The method of moving the leading end of a wire according to claim 1,

the step of measuring the position of the front end further comprises: a step of measuring the direction of the front end.

3. The method of moving the leading end of a wire according to claim 2,

the step of moving the front end to the target position comprises: and a step of aligning the direction of the tip with a predetermined direction.

4. The method of moving the leading end of a wire according to claim 2 or 3,

the direction of the tip is determined based on the shape of the linear object from the tip to a predetermined distance position.

5. The leading end moving method of a wire according to any one of claims 1 to 4,

the step of moving the front end to the target position, the target position being a hole.

6. The leading end moving method of a wire according to any one of claims 1 to 5,

in the step of moving the tip to the target position, the tip is moved by passing the tip through a predetermined near-front position and aligning a direction of the tip at the near-front position with a predetermined direction.

7. A control device for controlling the movement of a linear object by a manipulator provided in a robot,

acquiring the three-dimensional shape of the thread from a three-dimensional camera that acquires the three-dimensional shape of the thread,

acquiring the position of the leading end of the wire from the three-dimensional shape,

notifying the robot having the manipulator of information for moving the tip to a target position based on the position of the tip of the wire.

8. The control device according to claim 7,

the control device measures a direction of the leading end of the wire from the three-dimensional shape of the wire,

and notifying the robot having the manipulator of information for moving the wire to the target position so that the direction of the tip of the wire coincides with a predetermined direction.

9. A three-dimensional camera used when controlling movement of a linear object by a robot hand provided to a robot, the three-dimensional camera acquiring a three-dimensional shape of the linear object, wherein,

the three-dimensional camera includes a control device, and

the control device

Acquiring a three-dimensional shape of the thread from the three-dimensional camera,

acquiring the position of the leading end of the wire from the three-dimensional shape,

notifying the robot having the manipulator of information for moving the tip to a target position based on the position of the tip of the wire.

Technical Field

The present invention relates to a method for moving a tip of a linear object when the linear object is held by a robot, a control device, and a three-dimensional camera.

Background

Robots that recognize an object and hold the object by themselves using a three-dimensional camera or the like are becoming popular. As for the grip thread, for example, japanese patent laying-open No. 2014-176917 (patent document 1) describes the following: the robot device performs an assembly operation of a linear body, and moves a grip portion to the other end by sliding the grip portion along a predetermined trajectory after gripping the vicinity of a fixed end of the linear body having one end fixed. This makes it possible to quickly grasp the other end, which is difficult to accurately estimate due to a defect or the like of the wire as an example of the wire.

Japanese patent laying-open No. 2016-192138 (patent document 2) discloses an invention relating to a method for manufacturing a wire harness (wire harness) and an image processing method, wherein a processing position specifying process for specifying a processing position by measuring a three-dimensional shape of an electric wire assembly is performed in the process of manufacturing the wire harness.

Disclosure of Invention

Problems to be solved by the invention

The following can be considered: the robot holds, for example, a wire or the like as a linear object, and controls to move the tip of the wire to a predetermined target position. For example, assume control of inserting the wire tip into a through hole provided in an object. On the manipulator side, it is recognized that the linear object extends straight from the region gripped by the manipulator toward the distal end side.

However, in practice, a case is assumed in which the linear object is bent from the region gripped by the manipulator toward the distal end side. In this case, after the position of the distal end of the wire is recognized, the robot needs to move the distal end of the wire to the through hole provided in the object.

The present invention is directed to a method of moving a leading end of a linear object when the linear object is held by a robot, a control device, and a three-dimensional camera.

Means for solving the problems

The method for moving the tip of a linear object, which is used when the tip of the linear object held by a manipulator is moved to a target position, includes: measuring a position of the tip of the wire held by the manipulator; and moving the front end to the target position based on the measured position of the front end.

In another embodiment, the step of measuring the position of the front end further comprises the step of measuring the direction of the front end.

In another embodiment, the step of moving the tip to the target position includes a step of aligning a direction of the tip with a prescribed direction.

In another embodiment, the direction of the tip is determined based on the shape of the wire from the tip to a predetermined distance position.

In another embodiment, the step of moving the front end to the target position, the target position is a hole.

In another embodiment, the step of moving the tip to the target position moves the tip by passing the tip through a predetermined near-front position and aligning a direction of the tip at the near-front position with a predetermined direction.

The control device is a control device that controls movement of a wire by a manipulator provided in a robot, acquires a three-dimensional shape of the wire from a three-dimensional camera that acquires the three-dimensional shape of the wire, acquires a position of a tip of the wire from the three-dimensional shape, and notifies the robot having the manipulator of information for moving the tip to a target position based on the position of the tip of the wire.

In another embodiment, the control device measures a direction of the tip of the wire from the three-dimensional shape of the wire, and notifies the robot having the robot hand of information for moving the tip of the wire to the target position so that the direction coincides with a predetermined direction.

The three-dimensional camera is a three-dimensional camera used when the movement of a linear object is controlled by a robot provided in a robot, the three-dimensional camera acquires a three-dimensional shape of the linear object, the three-dimensional camera includes a control device that acquires the three-dimensional shape of the linear object from the three-dimensional camera, acquires a position of a tip of the linear object from the three-dimensional shape, and notifies the robot having the robot of information for moving the tip to a target position based on the position of the tip of the linear object.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the method for moving the distal end of the wire, the control device, and the three-dimensional camera, even when the region of the wire gripped by the manipulator is bent toward the distal end side, the manipulator side can be moved after the distal end position of the wire is recognized, and the distal end of the wire can be moved into the through hole provided in the object.

Drawings

Fig. 1 is a diagram showing an overall system for executing a wire holding method in the related art.

Fig. 2 is a flowchart of steps of a wire holding method in the related art.

Fig. 3 is a flowchart of the steps of the determination step of the thread holding method in the related art.

Fig. 4 is a diagram showing a first interference region and a first extended interference region in the related art.

Fig. 5 is a diagram showing a second interference region and a second expansion interference region in the related art.

Fig. 6 is a diagram for explaining the size of the first interference region in the related art.

Fig. 7 is a diagram for explaining a first determination step in the related art.

Fig. 8 is a diagram for explaining a first pre-determination step in the related art.

Fig. 9 is a schematic view for explaining a method of moving the tip of the linear object according to the embodiment.

Fig. 10 is a schematic view illustrating another method for moving the distal end of the string according to the embodiment.

Detailed Description

Hereinafter, a method for measuring a tip bending amount according to an embodiment of the present invention will be described with reference to the drawings. In the embodiments described below, when reference is made to a number, an amount, or the like, the scope of the present invention is not necessarily limited to the number, the amount, or the like unless otherwise specified. The same reference numerals are given to the same parts and corresponding parts, and the description may not be repeated. It is originally intended to appropriately combine and use the structures of the embodiments. In the drawings, actual dimensional ratios are not shown, and some ratios are shown differently in order to facilitate understanding of the structure.

In the following description, a case of using an electric wire as an example of the wire is described, but the present invention is not limited to the electric wire. The thread in this description may be any thread as long as it is an object having a long and thin shape. Examples of the thread include an electric wire, a wire harness, a solder, a rope, a thread, a fiber, a glass fiber, an optical fiber, a tube, and a dry surface. The present invention is not limited to the electric wire in which a bundle of thin wires is used, and includes an electric wire made of a single wire. In particular, the effect of the present embodiment is more remarkable when a linear object having a shape changed such as a curve or a linear object having no straight line is generated.

(correlation technique: thread holding method and control device)

An example of a thread holding method and a control device will be described below as related art with reference to fig. 1 to 8.

In fig. 1, an overall system 10 for implementing a wire gripping method includes: a robot 20, a three-dimensional camera 31, and a control device 32. A wire harness W including wires W1, W2, and W3 is disposed in the work space.

As the robot 20, a known articulated robot can be suitably used. The robot includes a manipulator 22 at the tip of an arm 21, and grips a linear object by a pair of grips 23 and 23 of the manipulator.

The three-dimensional camera 31 is not particularly limited as long as it can measure the three-dimensional shapes of the wire W1, the wire W2, and the wire W3. Preferably a stereo camera is used. The stereo camera is preferable for rapidly measuring the three-dimensional shape of the thread.

The stereo camera includes two cameras, obtains a point corresponding to a point to be measured on two images taken from different viewpoints, and calculates a three-dimensional position of the measured point by a principle of triangulation from a positional relationship of the two cameras. As for three-dimensional measurement of a linear object by a stereo system, for example, japanese patent laid-open No. 2-309202 discloses that a plurality of linear objects are captured by two cameras, and a corresponding point is determined by comparing the slope of the bright lines in two images with the distance between the bright lines as a feature, thereby reducing the processing time required for determining the corresponding point.

In the stereoscopic system, a line obtained by projecting a line connecting a viewpoint of one image and a measurement point on the other image (see japanese patent application No. 2017-221045) is referred to as an epipolar line (epipolar line), and a corresponding point on the other image corresponding to a point on the one image is projected on the epipolar line on the other image without fail.

By using the above principle, when a point corresponding to a certain point on a linear object is obtained, the intersection point of the linear object and the epipolar line can be obtained on another image, and the three-dimensional shape of the linear object can be measured quickly. When the linear objects are distinguished into different colors, the three-dimensional shape of each linear object can be obtained more quickly by extracting a corresponding color from the image using a color camera and obtaining a corresponding point.

The control device 32 communicates with the three-dimensional camera 31 via a communication unit, not shown, and acquires the three-dimensional shapes of the electric wire W1, the electric wire W2, and the electric wire W3 from the stand-alone camera. The control device determines, by an unillustrated arithmetic unit, whether or not the robot 22 is interfering with another linear object when gripping the linear object, based on the three-dimensional shape acquired by the independent body camera, and performs various calculations for determining a target linear object to be gripped.

The control device notifies the robot 20 of the gripping position of the target linear object to be gripped via the communication unit based on the calculation result. Not only the gripping position is directly notified to the robot 20, but also other devices (for example, a robot controller, a control personal computer, or the like) that control the operation of the robot may be provided between the control device 32 and the robot 20 and notified.

The method for holding a thread according to the related art will be described below with reference to fig. 2. The related art thread holding method includes: a step (S1) of measuring the three-dimensional shapes of the plurality of wires W1, W2, W3; a determination step (S2) for determining whether or not other linear objects interfere with each other when the manipulator 22 grips a linear object, based on the measured three-dimensional shape; and a step (S3) of holding a target linear object which is determined based on the determination result in the determination step S2.

The step S1 of measuring the three-dimensional shapes of the plurality of wires W1, W2, W3 is performed by the three-dimensional camera 31. The stereo camera captures an image of a certain working space of the wire, and performs arithmetic processing on two images to obtain the three-dimensional shapes of the wire W1, the wire W2, and the wire W3, respectively. The three-dimensional shape of the wire is represented by an orthogonal coordinate system or an oblique coordinate system, preferably by an orthogonal coordinate.

The control device 32 executes the determination step S2. The details of the determination step will be described later.

Step S3 of gripping the target linear object is performed by the robot 20. The robot notifies the control device 32 of the gripping position of the target linear object to be gripped, and moves the robot arm 21 and the manipulator 22 to perform the gripping operation.

The determination step S2 will be described in detail below.

Referring to fig. 3, in the determination step S2 of the related art, acquisition of a three-dimensional shape of a linear object (S21), selection of a linear object of interest (S22), determination of a gripping position of the linear object of interest (S23), acquisition of a manipulator standby position (S24), setting of various interference regions (S51 to S54), and various interference determinations (S61 to S64) are performed.

First, the control device 32 acquires the three-dimensional shapes of the electric wire W1, the electric wire W2, and the electric wire W3 from the three-dimensional camera 31 (S21).

Then, the control device 32 selects a target thread to be held by the manipulator 22 (S22). Hereinafter, the wire W1 will be referred to as a target wire to be gripped, and the wire W2 and the wire W3 will be referred to as wires other than the target wire (other wires). The control device may receive designation of a color of the electric wire from outside and determine the line of interest based on the designation. It is preferable that the control device autonomously (refer to japanese patent application No. 2017-221045) selects the line of interest.

For example, in the case of placing the electric wires W1, W2, and W3 on the stage, the wire located at the highest position, that is, the wire located at the uppermost position may be selected as the wire of interest, in accordance with the acquired three-dimensional shape. The reason for this is that: even when the linear objects are placed in a superposed manner, the probability that another linear object interferes with the linear object located above the linear object is lower.

Then, the control device 32 determines the holding position of the electric wire W1 to be focused (S23). For example, the control device calculates the gripping position of the target thread as three-dimensional coordinates based on a predetermined condition such as a distance of several mm from the tip of the target thread.

Then, the control device 32 acquires the standby position of the robot 22 (S24). When the standby position of the robot 22 is determined in advance, the coordinates thereof are acquired as the standby position. When the standby position is determined based on the three-dimensional shape of the linear object, for example, when the standby position is determined to be above the linear object by a predetermined distance, the standby position is acquired by calculation.

The controller 32 acquires the current position of the hand 22 from the robot 20, and moves the hand 22 to the standby position when the current position of the hand 22 is different from the standby position. The line segment connecting the standby position of the manipulator 22 and the holding position of the wire W1 provides a rough movement path when the manipulator 22 performs the holding operation.

Then, the control device 32 sets several interference regions including the gripping position of the target thread for the interference determination of the manipulator 22 with the electric wire W2 and the electric wire W3. In fig. 3, the first interference region, the first extended interference region, the second interference region, and the second extended interference region are set in this order. Interference determination is performed for each of all the other threads to determine whether the other thread is included in the respective interference regions.

The interference determination for each linear object can be performed by determining whether or not a point or a line segment on the linear object is located within the interference region or whether or not the line segment intersects the interference region while moving the point or the line segment in the longitudinal direction. In fig. 3, the second pre-determination for the second extended interference region, the second determination for the second interference region, the first pre-determination for the first extended interference region, and the first determination for the first interference region are performed in this order. Hereinafter, although the procedure is different from that of fig. 3, the interference determination for each interference region and the region will be described.

Referring to fig. 4, the first determination step S61 for the first interference region 51 determines whether or not the manipulator 22 has interfered with the other electric wires W2 and W3 when gripping the electric wire W1.

The first interference region 51 is a planar region including the grip position P of the electric wire W1 and having a predetermined shape and a predetermined size. The first interference region preferably includes a gripping location P at its center. The shape of the first interference region is not particularly limited, but is preferably a polygon, a circle, or an ellipse. When the first interference region is a polygon, the polygon is preferably a quadrangle, and more preferably a square. The reason for this is that: the calculation load becomes light, and rapid determination can be performed. When the first interference region is a polygon, it is particularly preferable to use a square having a side parallel to a plane formed by two arbitrary axes of a coordinate system (hereinafter, simply referred to as "coordinate system") representing a three-dimensional shape of the linear object as the first interference region.

The reason for this is that: the later-described first expansion interference region can be further reduced and the efficiency of the first pre-determination can be improved. In the case where the first interference region is not polygonal, a circle is preferable. The reason for this is also that: the calculation load becomes light, and rapid determination can be performed.

If the size of the first interference region 51 is too large, the probability that interference will occur will increase without actually occurring interference. Referring to fig. 6, if a circle C1 is defined as a smallest circle circumscribing the maximum cross section of the robot 22, the first interference region is preferably contained in a circle having a diameter 2.0 times that of the circle C1, and more preferably contained in a circle having the same size as the circle C1.

On the other hand, if the first interference region is too small, the probability that the interference occurs during implementation but the erroneous determination that the interference does not occur increases. Referring to fig. 6, if a circle C2 is defined as a smallest circle circumscribing a maximum cross section of the grip portion 23 that operates to grip the linear object by the manipulator 22, the first interference region is preferably of a size that can include a circle having the same size as the circle C2 (see japanese patent application No. 2017 and 221045).

The first interference region 51 is preferably orthogonal to the wire W1. The first interference region is orthogonal to the line of interest, and means that the direction in which the line of interest extends in the grip position P forms a right angle with the first interference region. The reason for this is that: the equation of the plane containing the first interference region can be easily found. In addition, the reason is that: when the linear object is gripped by the robot 22, the linear object is often gripped from the front side, i.e., from a direction perpendicular to the linear object. The reason for this is that: when another linear object is present in the first interference region orthogonal to the line object of interest, the manipulator 22 is highly likely to interfere with the other linear object even when the manipulator 22 does not grip the line object of interest from the front side.

Referring to fig. 7, the first determination step S61 may be performed by intersection determination of the segment L on the other electric wire W2 as the object and the first interference region 51. The line segment L may be a line segment between two adjacent points S, T in the three-dimensional point group of the wire W2. If the line segment L intersects the first interference region, a certain point on the line segment L is included in the first interference region. The cross judgment can be performed by a known method. For example, an inner product of a normal vector N of a plane U including the first interference region 51 and vectors PS and PT from the grip position P toward both ends S, T of the line segment L is obtained, and the line segment L intersects the plane U when signs of the two inner products are different. When the line segment L intersects the plane U, it is sufficient to determine whether or not the intersection point thereof is located within the first interference region 51.

Referring to fig. 4, the first preliminary determination step S62 for the first extended interference region 52 is performed before the first determination, and is performed in order to find out that the manipulator 22 does not interfere with the other wires W2 and W3 by faster calculation.

The first extended interference region 52 is a spatial region that encompasses the first interference region 51. The shape and size of the first interference region are not particularly limited, but it is preferable that the smallest of hexahedrons which include the first interference region and all sides of which are parallel to any one axis of the coordinate system be set as the first interference region. In the case where the coordinate system is an orthogonal coordinate system, the hexahedron is a rectangular parallelepiped. Thus, the first pre-determination can be performed only by comparing the magnitude of the coordinates.

Specifically, referring to fig. 8, when coordinates of 8 vertices a to H of the first expanded interference region 52 are set to (xS, yS, zS) and coordinates of an end point S on one side of the line segment L are set to (xS, yS, zS) as shown in fig. 8, if x1 ≦ xS ≦ x2, y1 ≦ yS ≦ y2, and z1 ≦ zS ≦ z2, the point S is located within the first expanded interference region, and if not, the point S is located outside the first expanded interference region.

Since the first expansion interference region 52 includes the first interference region 51, in the case where a result that the hand does not interfere with other linear objects is obtained by the first preliminary determination, the first determination can be omitted.

Referring to fig. 5, the second determination step (S63) for the second interference region 53 determines whether or not the manipulator 22 interferes with the other electric wires W2 and W3 on the path to the holding position P of the electric wire W1.

The second interference region 53 is a planar region including a line segment PQ connecting the holding position P of the wire W1 and the standby position Q of the robot 22, extending to both sides of the line segment PQ and having a predetermined width. The second interference region preferably includes a line segment PQ at the center in the width direction thereof. The shape of the second interference region is not particularly limited, but is preferably a rectangle or a parallelogram, and more preferably a rectangle having a line segment PQ as a symmetry axis of line symmetry. The reason for this is that: the burden of calculation is reduced, and the determination is performed more quickly.

If the width of the second interference region 53 is too wide, the probability that interference will occur will be erroneously determined to be actually not occurring. The width of the second interference region is preferably below the diameter of circle C1 of fig. 6. On the other hand, if the width of the second interference region is too narrow, the probability that the interference is generated during implementation but the erroneous judgment that the interference is not generated is increased (see japanese patent application No. 2017-221045). The width of the second interference region is preferably greater than the diameter of circle C2 of fig. 6.

The second interference region 53 is preferably set so that the angle with the electric wire W1 becomes maximum. The reason for this is that: when the manipulator 22 approaches the electric wire W1, the grip portion 23 and the grip portion 23 often move in such a plane.

Similarly to the first determination step S61, the second determination step S63 may be performed by determining the intersection of the segment L on the other electric wire W2 as the target and the second interference region 53.

The second pre-determination step (S64) for the second expansion interference region 54 is performed before the second determination, and is performed in order to find out that the robot 22 does not interfere with the other wires W2 and W3 by faster calculation.

The second extended interference region 54 is a spatial region that encompasses the second interference region 53. The shape and size of the second interference expansion region are not particularly limited, but it is preferable to set the smallest of hexahedrons, which include the second interference region and all sides of which are parallel to any one axis of the coordinate system, as the second interference expansion region. In the case where the coordinate system is an orthogonal coordinate system, the hexahedron is a rectangular parallelepiped. Thus, the second pre-determination can be performed only by comparing the magnitude of the coordinates.

Since the second interference region 53 is included in the second extended interference region 54, the second determination can be omitted when the result that the hand does not interfere with another linear object is obtained by the second pre-determination.

The determination steps S61 to S64 are repeated while the line segment L to be determined is moved in the longitudinal direction of the wire W2, and when the determination of interference with another wire W2 is completed, the same processing is performed on the next other wire W3.

When it is determined that all of the other wires W2, W3 are not included in the interference regions 51 to 54, the control device 32 determines that there is no interference of other wires when the hand 22 grips the grip position of the wire W1. Thereafter, the robot 20 is notified of the gripping position of the wire W1 as a target wire.

When it is determined in either the first determination or the second determination that the line segment L is included in the first interference region or the second interference region, the control device 32 determines that there is interference of another wire when the hand 22 grips the grip position of the electric wire W1. The subsequent determination step is omitted and the process returns to step S22, and the target thread is changed and the same process is repeated. In the case where the control device 32 autonomously selects the next wire of interest, for example, a wire located at the second highest position may be selected as the wire of interest based on the three-dimensional shapes of the wires W1 to W3 that have been acquired from the three-dimensional camera 31 before.

When it is determined that there is "interference" with any of the threads regardless of which thread is focused, the steps may be performed again after the entire thread is rotated to change the direction or the thread is swung or vibrated to change the positional relationship between the threads. The distance from the gripping position of each of the attention threads to the nearest other thread may be calculated as an interference distance, and the gripping may be performed from a thread having a long interference distance. This can instruct the robot to execute the gripping operation in the order in which the gripping is easy to succeed. The interference distance can be easily calculated by using the distance from the intersection of the first interference region or the second interference region in the interference determination and the other linear object to the grip position.

As described above, according to the wire holding method of the related art, since the holding operation is performed based on the determination result of whether or not the wire interferes with another wire, one wire can be selected from among a plurality of wires (see japanese patent application No. 2017-221045) and held by the manipulator 22.

The presence or absence of interference between the robot 22 and another linear object may be performed by calculating the presence or absence of intersection with the polyhedron using Computer Aided Design (CAD) data on the robot 22 side and three-dimensional shape data of the linear object. However, this method is excellent in the accuracy of determination, but it is a time-consuming process.

In the related art, since whether or not a linear object other than the target linear object exists in the first interference region can be determined by determining the intersection between the planar first interference region and the linear object, the amount of calculation is small, and the presence or absence of interference can be determined quickly. When there is no line other than the line of interest in the first interference region, the manipulator 22 is highly likely to be able to hold the line of interest without interfering with another line. The same is true for the second interference region.

The order of performing each determination step is not particularly limited, except that the first pre-determination is performed before the first determination and the second pre-determination is performed before the second determination. In the embodiment, the second determination step is performed first, and then the first determination step is performed, but the order may be reversed. In the related art, all the determination steps are performed for each line segment while moving the line segment L in the longitudinal direction of the linear object, but after one determination step (for example, the second pre-determination step) is finished for a certain linear object, another determination step (for example, the second determination step) may be performed again for the same linear object.

In the related art, the attention thread is selected (S22) before the standby position of the manipulator 22 is acquired (S24), but the standby position of the manipulator 22 may be acquired first and the attention thread may be selected according to the standby position. In this case, as the target thread, the thread closest to the standby position side may be selected. As the linear object closest to the standby position side, a linear object may be selected in which the distance between the coordinates of the standby position and the coordinates of the holding position of the linear object is shortest. Thus, the following are preferable: when the user grips the suture, the suture having a low possibility of interference with other sutures can be selected.

The posture (gripping posture) when the manipulator 22 grips the linear object is preferably such that the grip portion is held at a substantially right angle to the linear object. The reason for this is that: if the direction of the linear object on the tip end side from the holding position is substantially perpendicular to the holding portion, the robot can be easily controlled when the linear object is inserted into a processing machine or the like after being held. It is preferable to adjust the posture of the manipulator 22 at the standby position so that the grip portion becomes perpendicular to the linear object when gripping. Thereafter, the manipulator 22 moves from the standby position toward the holding position along the second interference region. This makes it possible to match the posture of the hand 22, the moving direction of the hand 22, and the direction of the plane of the first interference region and the second interference region, and thus to perform interference determination with high accuracy.

According to the present invention, the manipulator 22 holding the thread can also convey the thread to various manufacturing apparatuses and processing apparatuses. For example, the tip of the held electric wire may be moved by the robot 22 and inserted into a film peeling machine, a terminal crimping device, or the like. The leading end of the electric wire may be inserted into various components such as a connector and used in a process of manufacturing a wire harness.

(embodiment: method for moving tip of linear object, control device and three-dimensional camera)

Next, a case where the robot 22 provided in the robot 20 described above conveys the wire to various manufacturing apparatuses and processing apparatuses will be discussed. Specifically, the controller 32 (see fig. 1) controls the movement of the wire W1 by the hand 22 provided in the robot 20. Assume that the control device 32 acquires the three-dimensional shape of the wire W1 from the three-dimensional camera 31 that acquires the three-dimensional shape of the wire W1, acquires the tip position of the wire W1 from the three-dimensional shape, and notifies the robot 20 having the manipulator 22 of information for moving the tip W1s to the target position based on the tip W1s position of the wire W1.

The overall system 10 shown in fig. 1 includes a robot 20 having a hand 22, a three-dimensional camera 31, and a control device 32. The control device 32 may be any one of a control device independent of the robot 20 and the three-dimensional camera 31, a control device provided in the robot 20, and a control device provided in the three-dimensional camera 31.

As described above, the posture (gripping posture) when the manipulator 22 grips the linear object is preferably such that the grip portion is held at substantially right angle to the linear object. However, in the case of using a linear object having a certain degree of flexibility, it is assumed that the distal end side of the linear object gripped by the manipulator 22 is not straight but curved.

In this case, when the linear object is conveyed in a state where the manipulator 22 side does not recognize the curve of the linear object distal end side, the linear object distal end cannot be conveyed to the predetermined target position.

Therefore, it is preferable that the control device 32 measures the direction of the tip of the linear object from the three-dimensional shape of the linear object, and notifies a robot having a robot hand of information for moving the tip of the linear object to a target position so that the direction of the tip of the linear object coincides with a predetermined direction.

In the following embodiments, a method of measuring the amount of bending of the tip of the linear object when the linear object is conveyed to a predetermined position by the manipulator 22 gripping the linear object will be described below. In the following description, as an example of the conveyance to the predetermined position, a case will be described in which the tip W1s of the wire W1 as a wire is inserted into the hole TGH provided in the target TG.

Here, the diameter of the thread may be in a range that can be recognized by the three-dimensional camera, and is preferably 0.01mm to 10 cm. The hole TGH provided in the target TG may be of a size that allows insertion of a thread, and is preferably 0.01mm to 15cm in diameter, and the hole depth is preferably 2 times or more the diameter of the thread.

Referring to fig. 9, a state in which the wire W1 is held by the manipulator 22 is shown. The tip W1s of the wire W1 is bent so as not to extend substantially at right angles to the robot 22.

The position of the leading end W1s of the electric wire W1 held by the robot arm 22 is measured. At this time, when L1 is defined as the direction extending substantially at right angles to the robot 22, the amount of bending of the tip of the wire W1, i.e., how much the tip W1s is displaced from L1, can be measured. In the measurement of the position of the leading end W1s, the three-dimensional shape can be measured using the three-dimensional camera 31 described above. Thereby, the position of the leading end W1s and the offset amount X1 can be known.

Further, the shape of the wire W1 from the tip W1s to a predetermined distance position (distance D1 in fig. 9) is measured, and the direction in which the tip of the wire W1 extends can be determined by obtaining an average vector. Further, a vector connecting the tip W1s of the wire W1 and a position from the tip W1s to the insertion length of the hole may be taken as the direction of the tip.

This makes it possible to determine the direction of the appropriate posture when the tip W1s is inserted into the hole TGH provided in the target TG. The distance from the tip W1s of the wire W1 to the predetermined distance position (distance D1 in fig. 9) is preferably 0.3 to 10 times, and more preferably 0.5 to 5 times, the hole depth of the hole TGH provided in the target TG. The amount of curvature from the tip may be measured and the amount of curvature up to the sharp change point may be D1. Then, when the position or the amount of the bending of the tip W1s of the electric wire W1 is measured, the position or the amount of the bending of the tip is fed back to the movement control of the robot 22.

As shown in fig. 9, by providing a feedback amount from the position of the leading end W1s and the amount of leading end bending, the leading end W1s can be moved to the hole TGH provided on the target TG. In this case, the problem is less likely to occur when the hole depth of the hole TGH is shallow. However, when the hole TGH has a deep hole depth or when the diameter of the hole TGH is small and does not change much from the diameter of the electric wire W1, the direction of the tip W1s must be moved in accordance with a predetermined direction in which the electric wire can be inserted into the hole. Specifically, the tip W1s needs to be moved along the extending direction of the central axis TG-a of the hole TGH.

Therefore, as shown in fig. 10, the near position P11 on the extension of the center axis TG-a of the hole TGH is determined in advance, the tip W1s is moved to the near position P11, and the movement is performed so that the tip direction of the wire W1 coincides with the direction of the center axis TG-a of the hole TGH.

As for the moving method, the direction may be made uniform while the tip W1s is moved to the near position P11, or the wire W1 may be rotated so that the direction is made uniform at the near position after the tip W1s is moved in parallel to the near position. The proximal position is preferably in the vicinity of a target position, and when the target position is a hole, it is preferably on a line extending from the central axis of the hole. When the target position is a groove, it is preferably directly above the groove. When the target position is the terminal block, it is preferably on a line extending from the position of the connection terminal in the direction of the connection terminal.

Thereafter, the tip W1s is moved along the line extending along the center axis TG-a, and even when the hole TGH has a deep hole depth or a small diameter, the tip W1s can be inserted into the hole TGH.

Further, when it is judged by a sensor or the like whether or not the wire W1 can be inserted into the hole TGH and the insertion fails, the wire W1 may be returned to the near front position P11, the position and the direction of the tip W1s of the wire W1 may be measured again, the direction of the tip of the wire W1 may be made to coincide with the extending direction of the central axis TG-a of the hole TGH, and the tip W1s may be moved to the hole TGH.

A specific method of measuring the wire distal end bending amount of the wire W1 will be described below. For example, assume a state where the wire W1 having a length of 100mm is extended from the robot 22.

[ teaching of target position ]

Coordinates of the target position in the robot coordinate system are registered in advance. The manipulator 22 is caused to hold a straight bar B (refer to fig. 9) of 100mm instead of the electric wire W1. Since the robot 22 holds the proper position, the protruding length of the rod B is 100 + -several mm. The diameter of the rod B is made the same as the wire. Then, the above-mentioned bar B is scanned with a three-dimensional camera.

Next, the relative coordinates of the front end of the stick B can be calculated from the robot 22. The relative coordinates are held as reference data, for example, as in P1.

The front end of the lever is moved to a position of a hole into which the electric wire W1 is to be inserted. The front end position of the moved rod becomes the target position. The target position may be set in the hole or in the vicinity of the entrance of the hole. The coordinates of the moved tip of the rod in the robot coordinate system are registered as target positions. Which can be calculated by adding P1 to the coordinates of the manipulator. The location is registered as P0. This concludes the teaching of the target position.

[ movement of electric wire ]

The robot 22 holds the wire W1 to be moved. Thereafter, the wire W1 is scanned with a three-dimensional camera.

The relative coordinates of the leading end W1s from the robot 22 to the electric wire W1 can be calculated. For example, if the relative coordinate is P2, the robot is notified of the vector calculated from P0-P2 as a movement vector, and the robot moves the electric wire.

Thus, the position of the leading end W1s and the hole TGH coincide.

[ movement of electric wire + Direction Change ]

Here, P2 is the tip coordinate, and therefore, if the tip directions (Rx, Ry, Rz) are calculated simultaneously, the extending direction of the central axis TG-a of the hole TGH can be made to coincide with the extending direction of the tip of the wire W1 as described above. As for the moving method of the leading end W1s, the leading end W1s is moved in parallel to the predetermined near position P11 as described above, the leading end W1s is moved on the line extending along the center axis TG-a after the leading end W s is rotated so that the direction of the leading end of the wire W1 coincides with the direction of the center axis TG-a of the hole TGH at the near position P11. Further, the near position P11 may not be set, and the wire W1 may be moved from the initial position to the hole TGH while being rotated so that the extending direction of the tip end thereof coincides with the extending direction of the central axis TG-a of the hole TGH. The movement method may be any movement method as long as the distal end W1s of the wire W1 is moved to the predetermined position so that the direction of the distal end W1s coincides with the predetermined direction when the distal end W1s reaches the target position P0.

As an example of carrying the wire to the predetermined position, a case where the tip W1s of the wire W1 as the wire is inserted into the hole TGH provided in the target TG has been described, but the wire and the target position are not limited thereto. Specific examples of the target position as the hole include predetermined positions of an inspection device for inspecting a tip of an electric wire, a wire stripper (wirestripper) for stripping a coating of the electric wire, a processing machine for connecting the electric wire and a connector (connector), a processing device for crimping a crimp terminal to the tip of the electric wire, and the like.

As another example, when a wiring is soldered to a substrate, it is necessary to control the direction of the solder in accordance with the direction of the wiring or the position of another component. In this case, the present invention can be used with the wire as the solder and the target position as a predetermined portion of the substrate to be soldered or in the vicinity of a position directly above the predetermined portion of the substrate.

In addition, when the electric wire with the terminal is moved to the terminal block, since there is a restriction in the direction in which the terminal is connected to the terminal block, the electric wire with the terminal must be moved so that the direction of the electric wire with the terminal coincides with a predetermined direction in which the electric wire with the terminal is connected to the terminal block. In this case, the present embodiment can be used when the wire is a terminal-equipped wire and the target position is a predetermined portion of the terminal block or a vicinity of the predetermined portion. In this way, the target position is not limited to the hole, and may be a predetermined inspection position, a processing operation position, a surface, a groove, or a predetermined portion in the vicinity directly above these.

The embodiments disclosed herein are illustrative in all respects and should not be construed as being limiting. The scope of the present invention is indicated by the claims rather than the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein.

Description of the symbols

10: integrated system for holding a thread

20: robot

21: mechanical arm

22: mechanical arm

31: three-dimensional camera (stereo camera)

32: control device

51: first interference region

52: first expanded interference zone

53: second interference region

54: second expanded interference zone