JP2001315087A - Method for checking interference of robot arm in real time - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for checking interference of a robot arm with an interference range in real time by providing a simple robot arm model in a robot controller. SOLUTION: A robot arm is modeled by a combination of simple square poles. The current positions on a Z-axis of the upper surfaces and bottom surfaces of square poles 1, 2A and 3 are compared with those of the upper surface and the bottom surface of an interference range 7. After checking the interference, the current positions on the X-Y coordinate of squares 11, 13 as X-Y planar projection views of the square poles 1, 3 which is judged to have possibilities of interference are compared with the current position on the X-Y coordinate of a square 14 as the X-Y planar projection view of the interference range 7, and interference is checked.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a real-time interference checking method for a robot arm.

[0002]

2. Description of the Related Art A conventional robot controller uses a robot arm interference area check function in which a tip end of a hand attached to a robot arm attempts to move to an arbitrary point coordinate position in an operation space area of the robot arm. It is a function to determine whether or not to enter the interference area. The hand tip mentioned above is not a three-dimensional three-dimensional shape,
This is to determine entry into the interference area as a point. Checking the interference area of a robot arm having a three-dimensional solid shape with a robot controller significantly increases the processing load. Therefore, a personal computer system is prepared separately from the robot controller and simulated in advance by an application on the personal computer. Is used. Set a 3D solid model robot to be verified on the personal computer system, operate it with the robot operation program to be verified, check for interference in advance, and after verification by the personal computer system,
The verified robot operation program was loaded into the robot controller, and the verification by the actual machine was performed again. Also, when simulating with an application on a personal computer, it takes several seconds for each operation in the robot operation program.

[0003]

As described above, it has been known that the conventional robot arm having a three-dimensional three-dimensional shape has an interference check function inside the robot controller and performs the interference check during the robot operation processing. The processing load of the apparatus is remarkably increased. As a result, the conventional control processing time of 3 ms is reduced to about 1003 ms. As a result, the control processing speed of the robot operation, which is the main purpose of the robot controller, is reduced and the tact time is increased. There was a problem.

The present invention has been made in view of the above problems, and has as its object to provide a simple robot model inside a robot controller so that interference between a robot arm and a designated area can be checked in real time. It is to provide a way to do it.

[0005]

In order to achieve the above object, a real-time interference checking method for a robot arm according to the present invention has the following means.

The space area occupied by the robot arm is 1
First coordinate information relating to a model of a robot arm constituted by a combination of one or a plurality of polygonal pillars is stored in a robot controller, and second coordinates corresponding to an interference area preset for the robot arm are stored. Storing information in the robot controller, extracting first coordinate values corresponding to one end face and the other end face in a predetermined direction of the model of the robot arm from the first coordinate information, and extracting the second coordinate information; A second coordinate value corresponding to the one end face and the other end face in the same direction as the predetermined direction in the interference area is extracted from the first coordinate information, and a second coordinate value between the one end face and the other end face in the predetermined direction is derived from the first coordinate information. Check in real time whether there is an overlap of one distance and a second distance between the one end face and the other end face in the same direction as the predetermined direction derived from the second coordinate information, An outer peripheral line segment on the plane on which the robot arm model derived from the first coordinate information is projected, and an outer peripheral line on the same plane as the plane on which the interference region derived from the second coordinate information is projected; It has a method to check the intersection with the minute in real time, model the robot with a combination of simple polygonal pillars, and check the data overlap in real time with the coordinate value in the predetermined direction and the figure projected on the two-dimensional plane In this case, a simple check method is performed.

When the first distance and the second distance do not overlap, an outer peripheral line segment on a plane on which a model of the robot arm derived from the first coordinate information is projected and the second coordinate Checking the intersection of the plane where the interference area derived from the information is projected and the outer peripheral line on the same plane is omitted.

Further, the above-mentioned first coordinate information is changed in content in accordance with the operation of the robot arm, and has a function of checking in real time the interference between the robot arm and the designated area. did.

[0009]

FIG. 1 shows an embodiment of the present invention.
This will be described with reference to FIG.

FIG. 1 shows a simplified model in which the robot shape is represented by three quadrangular prisms. (A) is an XY plan view,
(B) is an XZ side view. The robot is modeled by a combination of simple square poles, and a simple 3
This implements a three-dimensional interference check function. Here, a vertical mechanism 6 in the Z-axis direction is
Type 1 is a robot that does not have a vertical mechanism.
A robot having a vertical mechanism 6 in the Z-axis direction at the tip of the arm 2 and a vertical mechanism in the mechanism of the rotary shaft 4
And

In the case of type 1, the square pillar 1 rotates about a rotation axis 4. The square pillars 2 </ b> A and 3 rotate around the rotation axis 5. The rotation shaft 5 rotates around the rotation shaft 4. The shapes of the square pillars 1 and 2A do not change regardless of the position or posture of the robot. The position of the bottom surface of the square pole 3 changes in accordance with the movement of the vertical mechanism 6 of the robot.

In the case of type 2, the square pillar 1 rotates about a rotation shaft 4. The square pillars 2 </ b> A and 3 rotate around the rotation axis 5. The rotation shaft 5 rotates around the rotation shaft 4.
The positions of the upper surface and the lower surface of the quadrangular prisms 1, 2A, and 3 change according to the movement of the vertical movement mechanism of the rotary shaft 4 in the Z-axis direction. Further, for the square pole 3, the amount of movement of the vertical mechanism 6 in the Z-axis direction is adjusted. However, the shapes of the square pillars 1, 2A and 3 do not change.

2A and 2B show an example of setting an interference area. FIG. 2A is an XY plan view showing an example of an interference check using an XY plane projected figure, and FIG. 2B is a ZX plan view showing an example of a Z-axis direction interference check. It is.

The Z-axis direction interference check will be described with reference to FIG. The position in the X and Y axis directions is ignored, and only the Z axis position is checked.

In the case of type 1, the square pillars 1 and 2A are:
The Z-axis positions on the top and bottom surfaces do not change regardless of the position or posture of the robot. Therefore, the interference determination of the quadrangular prisms 1 and 2A is performed when the comparison processing in the Z-axis direction is defined when the interference area 7 is defined, and the real-time comparison processing of the Z-axis position with the interference area 7 is not performed. The square pole 3 performs a real-time comparison process between the Z-axis position of the upper surface and the bottom surface based on the Z-axis position of the vertical mechanism 6 and the Z-axis position of the upper surface and the bottom surface of the interference area 7. In the example of FIG. 2B, it is determined that the quadrangular prism 1 has the possibility of interference and the quadrangular prism 2A has no possibility of interference. In this determination, the interference area 7 is changed regardless of the current position of the robot. It is effective until Therefore, it is not necessary to perform the determination processing in real time. The determination of the quadrangular prism 3 is performed in real time based on the current Z-axis position of the vertical mechanism 6, and FIG.
It is determined that there is a possibility of interference at the position in the example of FIG.

In the case of type 2, square pillars 1, 2A and 3
The Z-axis position changes depending on the position of the vertical mechanism of the rotating shaft 4 and the vertical mechanism 6 of the square pole 3. Therefore, the Z-axis positions of the top and bottom surfaces of the square pillars 1, 2A and 3 based on the Z-axis positions of the up and down mechanism of the rotating shaft 4 and the up and down mechanism 6 of the square pillar 3, Performs real-time comparison processing. Here, it is assumed that a quadratic prism overlapping with the interference area 7 in the Z-axis direction has a possibility of interference. In the example of FIG. 2B, it is determined that the square pillar 1 has a possibility of interference and the square pillar 2A has no possibility of interference. This determination is performed in real time based on the Z-axis position of the vertical mechanism of the rotating shaft 4. The determination of the square pillar 3 is performed in real time based on the Z-axis current position of the vertical mechanism of the rotating shaft 4 and the vertical mechanism 6 of the square pillar 3, and there is a possibility of interference at the position in the example of FIG. Is determined.

An interference check using an XY plane projected figure will be described with reference to FIGS. 2 (a) and 2 (b). The quadratic prism determined to have the possibility of interference in the Z-axis direction interference check is compared in the XY axis directions. In the simplified model of the robot arm and the figure in which the interference area 7 is projected on the XY plane, the projected figure of the square pillar 1 is a square 11, the projected figure of the square pillar 2A is a square 12, the projected figure of the square pillar 3 is a square 13, and the interference area The projection figure of 7 is a rectangle 14.
Since all of the rotating mechanisms of the robot rotate about the Z axis, the square obtained by projecting the square prism constituting the simplified robot model on the XY plane does not change its shape regardless of the position and orientation of the robot. Therefore, it is possible to check the interference area 7 on the XY plane based on the figure projected on the XY plane. Based on the joint angle positions of the robot to be checked, the end point XY coordinate positions of the rectangles 11, 12, and 13 are obtained as follows. First, a first matrix is obtained based on the angle of the rotation axis 4, and from the first matrix, four end point XY coordinate positions and a rotation axis 5 constituting the rectangle 11 are obtained.
XY coordinate position is obtained. Next, a second matrix is determined based on the angle between the rotation axes 4 and 5 and the XY coordinate position of the rotation axis 5, and eight end XY coordinate positions forming the quadrangles 12 and 13 are determined from the second matrix. The interference between the rectangles 11, 12, and 13 and the rectangle 14 is checked from the XY coordinate positions finally determined. The comparison between the rectangles 11, 12, and 13 and the rectangle 14 is performed by individually checking the intersections of the line segments forming each side of the rectangle. Since these are all calculated in a two-dimensional shape, they can be processed with a light load.

In the determination of interference, it is determined that there is a possibility of interference in the Z-axis direction, and if there is a square prism interfering with the figure projected on the XY plane, the robot arm is interfering with the interference area 7. Is considered.

These determination processes are performed in real time. However, quadrangular prisms determined to have no possibility of interference in the Z-axis direction interference check processing are excluded. FIG. 2 (b)
In the example of the above, since the quadrangular prism 1 is determined to have a possibility of interference in the interference check processing in the Z-axis direction, the interference determination processing of the square 11 on the XY plane is performed. In this case, since the square 11 and the square 14 do not interfere, it is determined that the square pillar 1 does not interfere. Since the quadrangular prism 2A is determined to have no possibility of interference in the Z-axis direction interference check processing, the XY plane interference determination processing is not performed. Although the rectangle 12 and the rectangle 14 at the current XY coordinate position interfere with each other, it is determined that they do not interfere because the interference determination processing itself is not performed. Since the square pillar 3 determines that there is a possibility of interference in the Z-axis direction interference check processing, the XY plane interference determination processing is performed. Since the rectangle 13 and the rectangle 14 at the current XY coordinate position are interfering, it is determined that they are interfering as a result of the interference determination processing.
For the robot as a whole, if there is at least one interfering square pole, it is determined that interference is occurring. The robot arm model described above may be a polygonal pillar other than a square pillar. As described above, since the interference determination of the robot arm can be performed by the processing inside the robot control device, no extra equipment such as a personal computer system is required. In addition, since a personal computer system or the like is not used, the procedure for creating the robot operation program is simplified by that step, and the program creation time can be greatly reduced.

[0020]

As described above, according to the present invention, the interference check of the robot arm is modeled by a simple combination of polygonal prisms without performing complicated calculations using a three-dimensional solid model, and the number of the predetermined directions is small. Since it is performed by comparing the magnitude of simple numerical values and calculating figures in a two-dimensional plane projected on the plane, the processing load of interference check is reduced, and while the robot is operating, interference determination is performed by real-time processing inside the robot controller Was made possible. Further, since the operation of the program can be directly verified on the actual machine, work errors on site can be greatly reduced.

[Brief description of the drawings]

FIG. 1 shows a simplified model in which a robot shape is represented by three square pillars, (a) is an XY plan view, and (b) is an XZ side view.

FIG. 2A is an XY plan view showing an example of setting an interference area, and FIG.
(B) is a ZX plan view showing an example of a Z-axis direction interference check.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Square pillar 2 Arm 2A Square pillar 3 Square pillar 4 Rotation axis 5 Rotation axis 6 Vertical mechanism 7 Interference area 11 Square 12 Square 13 Square 14 Square

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3F059 AA11 BC07 BC10 CA05 CA06 DA08 FA03 FA07 FA10 FC07 FC13 FC14 5H269 AB33 BB14 CC02 NN01 QE03 QE08 QE10

Claims (3)

[Claims] 1. The space occupied by the robot arm portion is 1
First coordinate information relating to a model of a robot arm constituted by a combination of one or a plurality of polygonal pillars is stored in a robot controller, and second coordinates corresponding to an interference area preset for the robot arm are stored. Storing information in the robot controller, extracting first coordinate values corresponding to one end face and the other end face in a predetermined direction of the model of the robot arm from the first coordinate information, and extracting the second coordinate information; A second coordinate value corresponding to the one end face and the other end face in the same direction as the predetermined direction in the interference area is extracted from the first coordinate information, and a second coordinate value between the one end face and the other end face in the predetermined direction is derived from the first coordinate information. Check in real time whether there is an overlap of one distance and a second distance between the one end face and the other end face in the same direction as the predetermined direction derived from the second coordinate information, An outer peripheral line segment on the plane on which the robot arm model derived from the first coordinate information is projected, and an outer peripheral line on the same plane as the plane on which the interference region derived from the second coordinate information is projected; A real-time interference checking method for a robot arm, which checks intersections with minutes in real time. 2. The outer peripheral line segment on a plane on which a model of the robot arm derived from the first coordinate information is projected when the first distance and the second distance do not overlap. Checking the intersection of the plane on which the interference area derived from the second coordinate information is projected and the outer peripheral line on the same plane is omitted. . 3. The method according to claim 1, wherein the first coordinate information is changed in accordance with the operation of the robot arm.