JPH02272605A - Sensor robot - Google Patents

Abstract

PURPOSE:To utilize the data of the detecting point of a preceding block by substituting data obtained by working detecting data detected at the preceding moving position of a moving device for a part of the positional data of plural specific points necessary for positional correction. CONSTITUTION:The center of an arc welding robot is moved to the center point 14 of the 1st block 12 and a difference between the center point 14 and a previously teached position is found out to correct the position of the 1st block 12. Then, the robot 1 is moved from the center point 14 of the 1st block 12 to the center point 18 of the 2nd block 13 and the inner angles 19 to 21 of respective ports are checked. The differences between the angles 16, 17 of the 1st block 12 and the angles 19, 20 of the 2nd block 13 correspond only to the thickness of a part 10, and the value is sufficiently small as compared to welding length, it may be almost neglected. Thereby, the inspection values of the angles 16, 17 can be directly used without newly sensing the angles 19, 20.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an industrial sensor robot that detects the position with a sensor and corrects the position before construction. The present invention relates to a sensor robot with an additional external axis for moving the body.

(Prior Art) A conventional sensor robot of this type will be described with reference to FIG. 4, taking an arc welding robot as an example.

In the figure, the moving device to which the arc welding robot 1 is attached consists of a gate-shaped X-axis moving table 3 that freely runs on a track 2, and a Y-axis carriage 4 that is slidably attached to the ceiling beam. ,
The arc welding robot V is composed of a Z-axis lifting platform 5 that is slidably mounted on the Y-axis reciprocating platform 4, and includes:
It is attached downward to the tip of the two-axis lifting platform 5 mentioned above. Note that the above moving device is a robot control device (not shown).
controlled by the external shaft.

For welding, the workpiece is divided into blocks of a size that can be performed by an arc welding robot in a fixed position, and each time one block is welded, the workpiece is moved from block to block using a moving device. Prior to welding each block, a sensor is used to check a predetermined specific point on the workpiece to correct the parallelism and rotation.

Three base points are required to correct the three-dimensional position of the workpiece, and these three base points are determined for each block prior to welding.
The conventional method is to find two reference points.

(Problem to be Solved by the Invention) However, in the above configuration, when the boundary between adjacent blocks is a single iron plate, the accuracy of the iron plate is sufficiently high that the position of one side of the iron plate is Once the position on the opposite side is known, there is no need to recalculate the position on the opposite side, but there is a problem in that sensing is performed again when the position is moved.

Furthermore, if the moving device moves to the next block, the position coordinates will be completely different even when working on both sides of the same part, so there is also the problem that data from the previous block cannot be used as is.

The present invention solves the above-mentioned problems and provides a sensor robot 1- which can utilize data of detection points of the previous block.

(Means for solving the problem) The three-dimensional position of construction is determined by adding the three-dimensional position determined by the robot arm and the three-dimensional position determined by the moving device, so each axis of the moving device is added to the arm to ROBONO 1. It can be controlled as an external axis. If you want to use a robot controller with the same number of control axes and divide the position data into the position determined by the robot arm and the position determined by the movement axis, and reuse the position already detected by the sensor, you can set the position data to a new position. A total of four position data, two types of each of the previous positions, are combined, processed into the required form, and used.

(Function) The detected point, which serves as the reference point for the new block, is a composite of the robot arm and movement axis data. On the other hand, since the movement axis data of the new block is known,
The difference becomes the new position of the detected point at that position.

(Example) An example of the present invention will be described using an arc welding robot as an example.
This will be explained with reference to FIGS. 1 to 4. Note that this embodiment does not differ in appearance from the conventional example shown in FIG. 4, and the robot control device (not shown) is equipped with a
The difference is that a device like 000, which can simultaneously distribute pulses to 12 axes including the 6 axes of the robot arm, is used.

Therefore, the same components are given the same reference numerals and their explanations will be omitted.

FIG. 1 is a perspective view of a large workpiece, in which a plurality of parts 7 to 11 are temporarily attached to a substrate 6.

Welding by the robot involves welding the parts 7 to 11 to each other or the parts 7 to 11 and the substrate 6. These processes are very similar to welding the inside of a box. Note that in FIG. 1, only a part of the substrate 6 is depicted and the rest is omitted.

Figure 2 is a plan view of the main parts of the workpiece, showing five parts 7 to 1.
1, it consists of two squares with a border in the center. The construction is carried out in a first block 12 and a second block 13 with the central part 10 as a boundary.

First, the center of the arc welding robot 1 is moved to the center point 14 of the first block 12 by driving the three axes of the moving device. Next, the upper part 8 and the left and middle parts 9 and 10. The inner corners 15, 16 and 17 of the lower part 7 and the center part 10, respectively, are used as convex quasi-points, and these are attached to the above-mentioned arc welding robot 1 as a sensor (not shown).
to find the difference from the previously taught position. 3
The position of the first block 12 is corrected based on the difference between the actual position obtained for the two reference points and the taught position. Once the actual position of the first block 12 has been determined, the arc welding robot 1 welds the corners 15, 16 and 17 from the inside.

Next, the moving device is driven again to move the arc welding robot 1 from the center point 14 of the first block 12 to the second block 13.
to the center point 18. When the movement is complete, the inner corner 19.2 of the central part lO, the upper and lower parts 8 and 7, the right part 11 and the upper part 8, respectively.
Check 0 and 21.

However, the corners 16 and 17 of the first block 12 and the second
The difference between the corners 19 and 20 of the block 13 is the thickness of the part 10, which is sufficiently small compared to the weld length and can be almost ignored.
0, corners 16 and 1 without sensing again
7 can be used as is.

Next, a method of determining the arm position will be explained.

When rPAJ is the position of the robot arm and rPEJ is the position of the external movement axis, the position of the entire system rP Sl is expressed as PS=PA+PE. For example, the position of corner 16 is r p 16J
If expressed as , corner 16 in Fig. 2 is P
(p 16). Angle 19 is PA (pl, 9) = PS (pl, 9) - PE (pl9)
becomes. From the above assumption, PA (pl9) = PA (pl6), so PA (p 19) = P S (p 16) - P
E (p 19)...(1) is converted to '4j). That is, the angle 1 is obtained by subtracting the position data PE (p, 19) of the external movement axis when newly moving to the center point 18 of the second block 13 from the data of the detected point P S (p 16).
Give the position of the arm of 9. In other words.

Center point 1 of the second block 13 while keeping the arm posture appropriate
The position of the external movement axis obtained by positioning at point 8 r P E
(p 1.9) J and r P given by equation (1)
The position of corner 19 is determined by ``A(pl9)''.

Strictly speaking, the position of the corner 19 determined as described above is the position PS (pl6) of the corner 16, and differs by the thickness of the component 10. It would be a problem to weld at different positions depending on the thickness of the plate, and it cannot be used. The reason why corner 16 and corner 19 can be made almost the same is because the difference in position between the taught point and the point when the work is actually placed is considered, and corner 19 as the construction point is set to corner 16. It cannot be replaced. To deal with this, the corners 16 and 17 of the first block 12 and the corner 21 of the second block 13 are used as three reference points, and a description will be given of how to define the coordinate system based on these points.

Suppose that the three reference points are S□, S2. Let's call it S3.

FIG. 3 is a plan view showing these lottery ticket systems.

First, consider the vector heading from S to 32 and define it as the X-axis direction. Next, consider a vector directed from S to S, and let the Z-axis direction be the vector determined by the back-to-back product of this vector and the X-axis vector. Since the X-axis and Z-axis are determined, the Y-axis direction is determined from the convention of the right-handed orthogonal system. Above S0
is the origin of the coordinate system.

When the coordinate system is defined in this way, So controls all position information, so even though three dimensions are required, the reference point S
2 may be two-dimensional to determine the direction of the straight line, and reference point S3 may be one-dimensional to determine the inclination of the plane; therefore, S2 and S
3. That is, even if there is a difference in thickness between the corners 16 and 17 shown in FIG. 2 by the thickness of the steel plate, it does not directly affect the position to be converted. As can be seen from FIG. 3, S2 and S3 affect the accuracy of rotational movement in coordinate transformation, but if the workpiece is a rectangle as shown in FIG. 2, they do not affect the transformation accuracy at all. Therefore, it can actually be applied to most rectangular workpieces.

Of course, the thickness of the part 10 may be separately taught to the robot control device d, and the corners 19 and 20, which take into account the thickness of the part IO, may be determined from the corners 16 and 17.

(Effects of the Invention) As described above, according to the present invention, when the construction position is checked using a sensor for each block moved by the moving device and the parallel rotational movement of the workpiece is partially corrected, the city Since the positions of detected points investigated in blocks can be used, work efficiency can be greatly improved.

[Brief explanation of drawings]

Fig. 1 is a perspective view of the main part of a large workpiece, Fig. 2 is a plan view of the main part, Fig. 3 is a plan view of the three-dimensional coordinate system, and Fig. 4 is a diagram of the arc welding robot attached to the portal moving device. FIG. 1...Arc welding robot, 2...Trajectory, 3
... X-axis moving table, 4 ... Y-axis reciprocating table, 5
... Z-axis lifting platform, 6... Board, 7°8, 9.
1.0.11...Parts, 12...First block,
13...Second block, 14...Center point of first block, 15.16.17.19°20, 21...Corner, 1B...Center point of second block. Fig. 1 6-11 Tile 7s, 9, 1o, 1t, one part Fig. 4 2-11 Asahi 3-X axis ~@7 4---Y axis, pillar 1 shi 5---Z axis Shoho included 2nd figure 7, 8.9.10j1 1 part 12-1 table 17" mouth/tsuku 13-1 line 210 tsuku 14--1 1st 170 tsuku j middle J (,!, 15.16.1
7.19.20.21--・Angle 78-=$27' mouth・/
ri 6) (point, Figure 3 1゜2゜3゜4゜procedure

Claims (1)

[Claims] A sensor robot consisting of an articulated robot that detects a specific point of a position detection sensor attached to the tip of a robot arm and corrects the taught position, and a two-dimensional or more moving device that moves the robot body. A sensor robot characterized in that a part of the position data of a plurality of specific points required for position correction is replaced by processed detection data detected at a previous movement position of a movement device.