JPS62160504A - Robot controller - Google Patents

Abstract

PURPOSE:To discriminate an actual welding start point during the robot operation and to start welding from this point by detecting the position of the actual welding starting point before the start of welding and obtaining a value to be corrected in accordance with the detected position to correct a robot. CONSTITUTION:The distance from a welding start point 12 stored in a position memory 1 to a point 19 where a sensor 7 detects the welding start point 12 is interpolated by an interpolating operator to operate the robot. The sensor 7 is started to detect the position of a point 15 of the designated edge by a detector, and the difference between the taught start point 12 and the actual start point 15 is obtained by an operator in accordance with the detection result, and the correction is completed, and the robot is operated to the position of a point 20. The robot is operated from the position of the point 19, where the start point 15 is detected, to the position of the taught start point 12 while adding a correcting value (d) stored in the memory, and the robot is operated from the point 20 to the actual start point 15. Then, the robot is operated up to the position of an actual welding end point 16.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a control device for a welding groove having a visual sensor having a function of detecting the position of a groove in welding.

(Prior Art) FIG. 2 is a control block diagram of a conventional welding robot control device. In the figure, (1) is the welding start point, (11) is the position memory that stores each welding end point, and ■ is the interpolation that calculates the path from the welding start point (1) to the welding end point 01). The arithmetic unit (8) is a detector that operates the visual sensor (7) and outputs the detected position in an absolute coordinate system (
9) is a correction calculator that calculates a path correction value from the position detected by the detector (8); ac! l is an interpolation verifier (■) and a correction calculator (an adder that adds the interpolated value obtained in step 9 and the correction value; ) The welding robot body operates according to the output of
(hereinafter referred to as a sensor).

Next, the operation will be explained. In Fig. 3(a), when welding from the taught welding start point O to the welding end point 0 using the sensor (7), the distance between the taught welding tangent line 14 and the actual welding line O''0 is The operation in FIG. 2 will be explained assuming a case where there is a deviation by d.

The interpolation value from the welding start point Q2) stored in the position memory (1), Ql) to the end point 0 is obtained using an interpolator, and at the same time, the sensor (7) is activated by the detector (8), and the specified Detect the position of the groove and calculate the correction value using the supplementary calculator (■). Then, the obtained interpolated value and the correction value are added by the adder 0@, and the result is exchanged with the actuator output value by the exchanger 2, and the robot body (5) is operated.

The torch (6) moves along the path ClID shown in FIG. 3(b) by the above-mentioned momentary operations.

[Problem that the invention seeks to solve]

When welding as described above, conventional robot control devices simultaneously perform interpolation calculations and correction calculations from the taught welding start point position, so the actual weld line must be removed before the correction is completed. There was a problem with welding.

This invention was made to solve the above-mentioned problems, and its purpose is to provide a robot control device that can determine the actual welding start point during robot operation and start welding from that point. do.

(Means for Solving the Problem) The robot control device according to the present invention detects the position of the actual welding start point with a sensor before starting welding, calculates a value to be corrected from the detected position, and controls the robot. This is corrected and the robot is operated to the actual welding start point position.

(Function) In the welding path according to the present invention, by moving the robot to the position of the actual welding start point before welding starts, the torch moves along the actual welding line from the welding start point to the end point.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, (a) is the part that moves to the position where the actual welding start point is detected, (1) is the welding start point position memory,
is an arithmetic unit that calculates the position to detect the actual starting point, ■ is 2
This is an interpolation calculator that interpolates between points. Here, it interpolates between two points from the welding start point position memory (1) to the detection position calculator (ri). (The slope is the result of the interpolation calculator ■ to the actuator output. The transducer (5) is a robot body that operates by the output of the transducer.

(b) is the part where the correction value of the teaching position is calculated and corrected from the actual welding start point detected by operating the sensor (7),
(8) is a detector that operates sensor 4-(7) and outputs the detected position in an absolute coordinate system, ■ is a correction calculator that calculates a value to correct the taught position to the actual position, (a), ( 5) is the same as (a) above.

(c) is the part that moves to the actual welding start point position, (
1) to (5) are the same as (a) above, QD is a memory that stores correction values, and 01llll is an interpolation calculator ■
An adder that adds the output value of and the correction value memory Q (0 is the torch at the tip of the robot).

Next, the operation shown in FIG. 1 will be explained with reference to FIG.

Figure 4 shows the movement of the torch at the tip of the robot with respect to the assumption in Figure 3(a) explained earlier. (a) - (b) - (c
) to (d). Further, here, it is assumed that a position separated by a distance r from the position of the tip of the handle is detected.

First, Fig. 4(b) shows the operation of Fig. 3(a), and the position detected by the sensor (7) is the welding starting point (l) from the welding starting point 02) stored in the position memory (1). point c
The robot moves by interpolating with the interpolation calculator (■).

Next, Fig. 4(c) shows the operation shown in Fig. 3(b) by activating the sensor (7) and detecting the position of the point Qω of the specified groove by the detector (
The correction value d stored in the memory Q2) is corrected to the difference between the 6 starting points taught by 8) and the actual starting point Il■, that is, the taught starting point 0. 9) until the correction is completed (point Q
Move the robot until it reaches the position Φ).

Figure 4(d) shows the operation of Figure 3(C), and the correction is stored from the position of point 09) where the starting point 05) was detected to the taught starting point (up to one position in memory Q). Operate the robot while adding the value d. That is, positions from point QΦ to c actual starting points are operated.

From here, the operation is similar to that of the prior art shown in FIG. 2 until the actual welding end point 00 is reached.

If we summarize the above routes, we get the route shown in Figure 3 (C).

(Effects of the Invention) As described above, according to the present invention, since the detection by the sensor is performed and corrected before welding starts, the actual groove is not removed from the welding start point to the end point, and the welding rate is high. This has the effect of improving quality.

[Brief explanation of drawings]

Fig. 1 is a control block diagram of a control device according to an embodiment of the present invention, Fig. 2 is a control block diagram of a conventional control device, Fig. 3 is an explanatory diagram showing a teaching example, and Fig. 4 is a control block diagram of a control device according to an embodiment of the invention. FIG. In the figure, (1) is the welding amount starting point position memory, (2) is the detection position calculator, (■ is the interpolation calculator, ■ is the actuator output converter, (5) is the welding robot body, and (7) is the visual sensor. , ■ is a sensor detector, (9 is a correction calculator, and Qθ is a correction value memory. The same symbols in the figure indicate the same or corresponding parts. Agent: Masashi Sato, Patent Attorney Figure 2)

Claims (1)

[Claims] In a teaching-playback robot that memorizes the position of the tip of the robot hand as a continuous trajectory of the hand and moves from this memorized position to a predetermined position, a visual sensor that finds a specified shape and detects its position is installed. A means for attaching it to the hand and detecting the actual position with a sensor rather than the position taught while online, and interpolating the robot body to this determined position, and a means for activating the visual sensor and detecting the position. A robot control device comprising: means for determining a correction value and correcting the robot body; means for moving the robot body to a detected actual position; and means for playing back while making the correction.