JPH06344121A - Teaching method for robot - Google Patents

Abstract

PURPOSE:To relieve the burden of an operator in teaching a robot by measuring the coordinate value by which the position and direction of a constraint surface and a material to be worked using a three-dimensional position measuring instrument. CONSTITUTION:Points 10 to 13 of the material to be worked 1 are measured by using the three-dimensional position measuring instrument 7 and the measured data are inputted in an electronic processing unit 30. For a burr 2, points 20 to 22 are selected along the parting line 5 and selecting information is inputted in the processing unit 30. The position and direction of parting surface 3 including the burr 2 are calculated and information on the working direction shown on a coordinate system 6 is made clear. Then, the relation of the value of position and direction of parting surface 3 and the coordinate of points 10 to 13 is made clear by the processing unit 30. By the calculation, the direction of parting surface 3 is given as the direction of surface determined with points 10 to 13 and a point 20 on which the relation to the material to be worked is made clear is formed on the parting surface 3 as the bound surface. From the relations, the parting surface 3 is determined by measuring the position coordinates of points 10 to 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for teaching a robot, which can reduce an operator's work load and perform an appropriate work in a work for removing a flash generated on a casting by a robot, for example. The present invention relates to a method for teaching a robot to perform.

[0002]

2. Description of the Related Art Conventionally, in the above-mentioned work using a robot, the position required for the work of the work object, the attitude of the end effector at that position, and the force required in the case of the work It is necessary to teach the robot the size accurately and efficiently.

For example, in order to execute a deburring operation by a robot, it is necessary to move the tool while following the burrs to be removed and maintaining the force required for grinding and the direction of the tool at appropriate values. It is necessary to accurately teach the robot information about the position and orientation of the robot.

However, the input of such information is a heavy burden in performing the work using the robot.

[0005]

Generally, as a method of teaching such work information to a robot, a hand effector of the robot is directly positioned on a work object along a path to be worked, and the position is stored one by one. Although the direct teaching method is often used, the burden on the operator of this teaching data input operation is very heavy.

Further, in the case of deburring a cast product as an example, since the variation in size and shape of the cast product is larger than the finishing accuracy of the deburring, in order to sufficiently reduce the residual flash height after the deburring process. However, since it is necessary to accurately measure the position of the flash for each individual product, the burden of teaching work is further increased.

Therefore, a sensor feedback system has been used in which the route measurement of this flash is automated by using a visual sensor and the robot is moved along the measured route to perform the work.

However, in this method, when the work path of the work object is detected by the sensor, the measurement value includes an error due to the influence of noise, and the work path is detected if the sensor reaches a portion where there is no flash. There was a problem that I could not do it.

Further, the information on the direction in which the force is applied cannot be directly obtained from the route information, and it is necessary to teach it separately or to provide a means for calculating the direction information of the force from the route.

Further, there is a problem that the measurement performed along all the routes takes time and reduces the work efficiency.

Therefore, the present invention has been made in view of the above points, and in order to solve the problems of the above-mentioned route teaching, for example, in the work of removing the flash generated in the casting Utilizing the property that the path is included in the mating surface (parting surface) of the mold, information about the surface is given to the robot accurately and efficiently with a small amount of teaching work, and individual products are detected by the sensor when the work is executed. By making it possible to correct it at the same time, the robot can be easily and accurately provided with route information necessary for robot movement and direction information regarding the cutting of burrs to reduce the operator's work load and perform accurate work. An object is to provide a teaching method for a robot that enables execution.

[0012]

According to the present invention, a work is performed by moving the tip of the end effector in a specific positional relationship with the work object in the whole or a part of the work. In a method of teaching a robot, a first step of measuring coordinate values indicating a position and a direction of the constrained surface and the work object from the work object using a three-dimensional position measuring device, and the constrained surface from the measurement result. The relationship between the position and direction of the and the point on the work object,
The second stage of forming a point or line segment having a clear positional relationship with the work object on the constraining surface, and the position of the point or line segment on the constraining surface with which the relationship with the work object is obtained. And a third step of correcting the position and the direction of the restraint surface obtained in the second step by measuring the direction and the direction of each work object with a sensor. A method of teaching a robot, characterized by determining a surface is provided.

[0013]

First, in the first step, the coordinate values of the position and direction of the work object and the restraint surface are measured by the three-dimensional position measuring device.

Next, in the second step, the positional relationship between the position and direction of the constraining surface and the point on the work object is clarified, and the point on the work object or the work object having a clear positional relationship is defined. A line segment is formed on the constraining surface.

Subsequently, in the third step, the sensor measures the coordinate values of the position and direction of a point or line segment on the work object having a clear positional relationship for each work object, and
The coordinate plane of the position and direction of the constraining surface obtained in the first step is corrected.

Through the above procedure, the restraint surface including the work route is determined for each work target.

[0017]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 shows the characteristics of flash generation in a casting produced by casting as an example.

In FIG. 1, reference numeral 1 is a work object which is a cast product, 2 is a flash generated around the work object, and 3 is a mating surface of a mold used for molding the work object 1 (a party). The burr 2 is generated so that a part of the work target 1 flows out between the molds and is included in this plane.

Reference numeral 4 denotes a base material surface of the work object 1 to which the flash adheres, which is perpendicular to the parting surface 3.

Reference numeral 5 denotes a connecting portion of the flash 2 to the work object 1, which is a line of intersection between the parting surface 3 and the base material surface 4, and is called a parting line.

Reference numeral 6 is a coordinate system showing the directionality of deburring work at one point on the parting line 5, the x-axis is the direction perpendicular to the parting surface 3, the y-axis is the tangential direction of the parting line 5, and z. The axis is included in the surface of the parting surface 3 and is a direction perpendicular to the base material surface 4.

The tool blade surface for deburring is x in the coordinate system 6.
Positioned in the axial direction, the deburring shaving process is performed in the plane of the parting 3 in the z-axis direction.

Reference numeral 7 is a three-dimensional position measuring device for measuring the position of the object to be measured by applying its tip to the object to be measured.

Each of 10, 11, 12, and 13 has a characteristic shape because it can be measured by the three-dimensional position measuring device 7 and is a point on a vertex or a ridgeline. It is a point on the work target 1 that can be easily detected when there is.

The position and orientation of the work object 1 can be determined by measuring the position of each of these points with the three-dimensional position measuring device 7 or the visual sensor.

Reference numerals 20, 21, and 22 are points along the parting line 5, and the parting surface 3 as a plane can be determined by measuring with the three-dimensional position measuring device 7.

Reference numeral 30 stores the position information of each point 10, 11, 12, 13 and 20, 21, 22 and the like measured by the three-dimensional position measuring device 7, and calculates and corrects necessary coordinates and corrects the data. It is an electronic processing device for displaying.

In the present invention, as the first step, the three-dimensional position measuring device 7 is used to measure each point 10, 11, 12, 13 on the work object 1, and the position information is electronically processed. Input to the device 30.

Further, with respect to the flash 2, appropriate three points 20, 21 and 22 along the parting line 5 are selected, and the positional information thereof is input to the electronic processing unit 30 using the three-dimensional position measuring device 7.

Based on the positional information of these three points 20, 21 and 22, the electronic processing unit 30 calculates the information of the position and the direction value of the parting surface 3 as the surface including the flash 2.

By thus clarifying the direction of the parting surface 3, the work direction information shown in the coordinate system 6 becomes clear.

Next, as a second step, the electronic processing unit 30
At, the position of the parting surface 3, the direction value and the point 10,
The relationship with the position coordinates of 11, 12, and 13 will be clarified.

In the example of FIG. 1, the relative relationship between the direction of the plane determined by the points 10, 12, and 13 and the plane direction of the parting plane 3 (parallel in the example of the figure), and the point 20 and the point 10 Point 1
The relationship between the position of the parting surface 3 and the position of the work object 1 is clarified from the position on the straight line connecting the 1's.

By this calculation, the direction of the parting surface 3 is given as the direction of the surface determined by the points 10, 12, 13 and the positional relationship with the work object is clarified.
Is formed on the parting surface 3 as a restraining surface to give the position of the parting surface 3.

Due to these relationships, some characteristic points 1 of the work object 1 which can be measured by the visual sensor 1
By measuring the position coordinates of 0, 11, 12, and 13, the position and direction of the parting surface 3 can be obtained from this coordinate value, and the parting surface 3 can be determined.

The first and second steps may be performed only for one sample of the product to be deburred.

FIG. 2 shows a case where the flash does not exist on the same plane and the surface including the flash is composed of a plurality of surfaces.

In FIG. 2, 9 is a work object which is a cast product, and 40, 41 and 42 are respective constraining surfaces including the individual portions of the flash 2.

Reference numeral 50 denotes a line of intersection of the two planes of the constraining surfaces 40 and 41, and 51 denotes a line of intersection of the two planes of the constraining surfaces 41 and 42.

Reference numerals 52 and 53 denote intersection points where the intersection lines 50 and 51 intersect the base material surface 4, respectively.

54, 55 and 56 are present along 5 and 3
This is a point that can be measured by the dimensional position measuring device 7.

In this example, regarding the intersecting lines 50 and 51, for example, a straight line formed by the points 55 and 56 is used as the three-dimensional position measuring device 7.
The position and the direction can be determined by measuring the direction with the three-dimensional position measuring device 7 at the intersections 52 and 53.

As a result, the intersecting lines 50 and 51 are the constraining surfaces 40 and 41, as line segments whose positional relationship with the work object 9 is clear.
Formed on 42.

Here, 61 and 62 are characteristic points of the work object 9 in the vicinity of the intersection 52, which can be detected by a visual sensor or the like.

Similarly, 63 and 64 are characteristic points of the work object 9 near the intersection 53.

Therefore, by measuring the positional relationship between the points 61 and 62 and the intersection point 52 and the positional relationship between the characteristic points 63 and 64 and the intersection point 53 by the three-dimensional position measuring device 7,
Feature points 61, 62 and 63, 6 by a visual sensor or the like.
By measuring 4, it is possible to determine the position of the intersection points 52, 53. This intersection 52, 53, 54, 55
By combining with the intersection lines 50, 51, the planes of the constraining surfaces 40, 41, 42 can be determined.

3A and 3B, as the third step of the work example in FIG. 2, the positions of the feature points on the work target 9 are measured by the visual sensor, and the constraint data measured in the first step using the position data. The process of correcting the surface position for each product according to the variation, positioning the tool on the flash according to the value, and grinding and removing the flash is shown.

In FIG. 3, 31 is a robot used for deburring, 32 is attached to the robot 31,
It is a position measuring device (sensor) capable of measuring a characteristic position of the work target 9.

The position measuring device 32 has feature points 61, 62,
It has a function of measuring the characteristic points of the work object 9 such as 63 and 64, and the measurement result is used as the electronic processing unit 30 of FIG.
Transfer to.

33 is a grinding tool for deburring,
The robot 31 uses the constraining surface 4 to position the grinding tool 33.
The position and direction data for 0, 41, 42 are received from the electronic processing device 30, and the force is controlled by pressing the grinding tool 33 in the z-axis direction in FIG. Position the tool 33 at the burr 2 position.

In this example, the directions of the intersecting lines 50 and 51 have already been given at the stage described in the explanation of FIG.

Here, the position measuring device 32 operates to measure the position of the intersection point 52 by detecting the characteristic points 61 and 62 and the position of the intersection point 53 by detecting the characteristic points 63 and 64.

As a result, the intersection lines 50 and 51 are determined.

When the variation of the product in the restraint surface direction is small, the position data of the restraint surfaces 40, 41, 42 obtained in the second stage can be obtained from the intersection lines 50, 51 only by the parallel movement correction. The error is small.

When the product has a large variation in the constraining surface direction, 65, 66 or 67, 6 of the work object 9 is used.
By additionally acquiring the positions of the points 55, 54, etc. from the characteristic point measurement of 8, etc., these can be combined with the intersection lines 50, 51 to determine each of the constraining surfaces 40, 41, 42.

As described above, in this example, the position measuring device 32 is used to efficiently correct the position of the parting surface including burrs for each individual product by re-measurement of the representative points only, and the constraining surface is corrected. The vertical positioning can be performed with high accuracy, and the grinding tool 33 is moved based on the data to perform the deburring work.

FIG. 4 is a flowchart showing the procedure according to the present invention as described above.

That is, in step 1, the coordinate values of the position and direction of the work object and the restraint surface are measured by the three-dimensional position measuring device. (Corresponding to the above first step) In step 2,
Clarify the positional relationship between the position and direction of the constraining surface and the point on the work object.

In step 3, points or line segments on the work object having a clear positional relationship are formed on the constraining surface.
In step 4 (corresponding to the above second step), the sensor measures the coordinate value of the position and direction of the point or line segment on the work object having a clear positional relationship for each work object.

In step 5, the coordinate values of the position and direction of the constraining surface obtained in step 1 are corrected. (The above corresponds to the third stage) In step 6, the restraining surface including the work route is determined for each work target by the above procedure.

[0062]

As described above, according to the teaching method for a robot of the present invention, when deburring is taken as an example, it can be grasped as a plane including burrs, and its existence position can be taught regardless of the presence or absence of the deburring. By correcting the position of the representative point for each individual product, simple and accurate teaching is possible, and by clarifying the direction of the surface including burrs, the direction of force for grinding work is clarified. It is possible to do so.

[Brief description of drawings]

FIG. 1 is a diagram showing a feature of a flash generation state of a casting manufactured by casting as an example of the present invention.

FIG. 2 is a diagram showing a case where burrs do not exist on the same plane and a surface including burrs is constituted by a plurality of surfaces as another example of the present invention.

FIG. 3 is a diagram showing a work for grinding and removing flash as an embodiment of the present invention.

FIG. 4 is a flowchart showing the procedure of the present invention.

[Explanation of symbols]

1, 9 ... Work object, 2 ... Burr 3 (40, 41, 42) ... Parting surface (restraining surface), 4 ... Base material surface, 5 ... Parting line, 6 ... Coordinate system, 7 ... Three-dimensional position measurement Bowl, 10, 11, 12, 13, 61, 62, 63, 64, 6
5, 66, 67, 68 ... Characteristic points, 30 ... Electronic processing device, 31 ... Robot 32 ... Position measuring device (sensor), 33 ... Grinding tool.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Shinichi Meguro 1-6, Uchisaiwai-cho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation (72) Inventor Satoshi Iwaki 1-6-1, Uchisaiwai-cho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation

Claims (1)

[Claims] 1. A teaching method for a work robot, wherein machining is performed by moving a tip of an end effector in a specific positional relationship with a work object in the whole or a part of the work, wherein the constraint is provided. The first step of measuring the coordinate values indicating the position and direction of the surface and the work object from the work object using a three-dimensional position measuring device, and the position and direction of the constraining surface and the work object on the work object from the measurement result. The second step of forming a point or line segment on the constraining surface that has a clear positional relationship with the work object and the relationship with the work object on this constraining surface is obtained. And a third step of correcting the position and direction of the constraining surface obtained in the second step by measuring the position and direction of the point or line segment for each work object by a sensor, and these. According to the procedure Teaching method to the robot, characterized by determining the constraint surface including a working path Te.