JPS649154B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a playback type industrial robot, and particularly to one that makes it easy to modify taught information.

Playback type industrial robots are well known. It is also known that each piece of taught information can be modified later.

However, it was not easy to find the step that I wanted to modify, so I had no choice but to call up the step I had an idea of and use cut and try.

Therefore, in this invention, by manually moving the end effector of an industrial robot to the vicinity of the part to be corrected and issuing a search command, it is possible to automatically search for a step close to the part to be corrected. The aim is to provide an industrial robot that solves these problems.

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

FIG. 1 is an overall view including a rectangular coordinate welding robot RO, which forms the background of this invention and is effective in carrying out this invention, but this invention is not limited to this embodiment.

1 is a well-known rectangular coordinate (x,
y, z) are the vertical axes configured at the terminal of the robot RO.

Reference numeral 2 denotes a first arm supported at the lower end of the vertical shaft 1 so as to be able to rotate α around the shaft 1.

A second arm 3 is supported at the tip of the arm 2 by an oblique shaft 3a so as to be rotatable β. At the tip of the second arm 3 is a processing tool (in this embodiment) as an end effector.
A gripping tool 3b for gripping the MIG welding torch T) is provided.

and the central axis of shaft 1, shaft 3a and torch T
The TCs are constructed so that they can intersect at one point P.
Furthermore, the torch T is configured such that its welding operating point can coincide with the point P. Thus, by controlling the angles α and β, the attitude angle θ and the turning angle of the torch T with respect to the vertical axis 1 can be controlled.

4 is a known welding power supply device. The device 4 is equipped with a spool 4a that winds up the consumable electrode TW of the torch T, and the welding electrode 4 is installed between the electrode TW and the workpiece WK.
b.

Reference numeral 5 denotes a known computer as a control device for the entire embodiment. Computer 5 has
Including CPU and memory.

A power supply 4b is connected to the bus line B of the computer 5.

The bus line B is further connected to the x-axis servo system Sx of the robot R. The servo system Sx has the x-axis power Mx and an encoder that outputs its position information.
Includes Ex. Similarly, bus line B has a y-axis servo system Sy, a z-axis servo system Sz, an α-axis servo system Sα, and a β-axis servo system configured in the same way.
Sβ is connected.

The RE is a remote control panel and is equipped with a group of manually operated snap switches. If you turn the snap switch for each of the x, y, and z control axes to the "U" side, the position information for that control axis will increase.
The end effector is configured so that when it is turned to the "D" side, the end effector moves in the opposite direction. Also, the snap switch corresponding to each control angle of θ and is “C”.
It is configured so that the torch T rotates clockwise when tilted to the side, and counterclockwise when tilted to the "CC" side.

The operation panel RE is also provided with a speed command rotary switch SV. Furthermore, a mode changeover switch SM is provided so that the mode can be switched to manual mode M, test mode TE, and auto mode A. SE is a designated switch, and by switching it upward in the figure and operating the up-down switch SU, you can select the teaching step number (P
No.) is displayed and made to be selected. Furthermore, by switching this switch SE to the left as shown in the diagram and operating switch SU,
Linear interpolation “L”, circular interpolation “C”, search command “S”
It is designed to be selected and displayed in this order. Furthermore, when the switch SE is switched to the right in the figure and the switch SU is operated, the welding condition number (WNo.) is displayed and is to be selected. Furthermore, the operation panel RE is equipped with a start switch ST. The functions of the switch ST will be explained in detail in the explanation of the operation described later. Furthermore, SS is a group of axis designation switches for each control axis. Further, D is a display means for displaying deviations (details will be described later) regarding the control angles α and β. The switches and display means provided on the control panel RE mentioned above are all connected to the bus line B.
connected to.

In addition, when Switch SV is in manual mode,
By pressing the head, the moving speed of the torch T in the manual mode is stored as a constant value.

The effects of the above-mentioned embodiments will be described below.

First, as shown in the figure, the workpiece WK is two blocks that are welded together along the horizontal fillet weld line WL, between _{P1 P2} , _{P2 P3} , _{P3 P4} and P3. ₄ Assuming that linear interpolation is performed between P ₅ , each point P ₁ to
It is assumed that command information is taught at each teaching point of _P5 .

The operator sets switch SM to manual mode M as shown. Then set the switch SV to the desired speed in manual mode M,
Hold that head.

Next, if you operate the switch group SW, the robot
Each control axis of the RO moves at the set speed in the manual mode set above, and thereby the position of the torch T is moved by the manual, and the welding point P of the torch T is moved to P ₁ as shown by the two-dot chain line in the figure. Match with
The angle θ is controlled so that the torch T is in a position suitable for horizontal fillet welding from point _P1 to _P2 . Then, in auto mode, set the command speed for moving the torch T to point _P1 in the switch SV,
Furthermore, when the switches SE and SU are operated to set the W number to zero, that is, a command that does not perform welding, and the start switch ST is operated, the computer 5 receives the encoder output information for each control axis of the robot RO and the above-mentioned information. Each command information is read and stored at an appropriate address in the memory as the first teaching step of the user program.

Next, the operator operates the switch SW to manually move the torch T in the same way, and positions the welding point P of the torch T at _P2 . Further, the switch SV is operated to set the speed at which the torch T should be moved from point _P1 to _P2 , that is, the welding speed _V1 .
Also, operate switches SE and SU to input linear interpolation command L and welding condition number from point P ₁ to P ₂ .
Set W ₁ respectively. On top of that, Switch ST
As before, if you operate , you will get the encoder output information for each control axis of the robot RO at point _P2 , the set welding speed _V1 information, the linear interpolation command L information,
and welding condition _W1 information are stored as the next teaching step of the user program.

Thereafter, each step of the user program at each teaching point, P ₃ , P ₄ , P ₅ , is taught in the same manner.

After completing the teaching as described above, the operator then sets the switch SM to the test mode TE. When the switch ST is operated, the computer 5 executes the first step of the user program. That is, the torch T is positioned at point _P1 . Next, switch ST
When operated, the computer 5 executes the next step of the user program. That is, the torch T moves from point P ₁ to point P ₂ at a commanded speed V ₁ using known linear interpolation means according to the system program. However, in this case, the power source 4b does not operate. In this way, the switch
Each time the ST is operated, each step of the user program is executed, except for welding. If there is a problem with the program during this time, set the switch SM to manual mode M, operate switches SE and SU to call the required step number P, set the command information you want to correct, or correct the position and orientation of the torch T. Then, if you operate switch ST, the information about that step will be corrected.

Further, when the operator operates the switch SM to set the auto mode A and operates the switch ST, a series of welding operations are executed in succession in the order of the steps of the user program described above.

As a result of this work, if there is any further problem in the user program, operate the switches SE and SU to call up the step number to be corrected, and then perform the same operations as described above to correct it.

However, if the steps of the user program are simple as in the above embodiment, there is no particular problem, but if the steps are complex and the desired step number is unknown, or if there are additional steps after the first taught step. If the step number is unknown due to addition or deletion, it will be difficult to modify the user program with the configuration described above.

The following is a description of the features of the present invention, including a configuration for calling the desired step for modifying the program as described above without error. See also Figure 2.

As mentioned above, when executing a program in auto mode, if the operator finds an inconvenient part later and wants to call that step, the operator sets the switch SM to manual mode M and operates the switch group SW to correct it. Position the torch T near the desired location. Furthermore, select search command S by operating switches SE and SU. Then operate Switch ST.

The computer 5 receives this search command S (search step S ₁ ) according to a pre-programmed system program, and inputs and stores the position information of each axis of the robot RO at the current position Pp of the torch T (search step S 1 ). ₂ ).

Furthermore, the computer 5 calculates the difference ΔP in positional information between the position Pn of the tip of the torch T for each step in the user program and the current position Pp of the tip of the torch T (search step
_S3 ).

Next, Pnmin at the step when ΔP obtained in this way becomes min is determined (search step S ₄ ). This compares ΔP at each Pn,
It is sufficient to memorize the point Pn with the smaller value.

Angles α, β in Pnmin and in Pp
The difference between Δα and Δβ is calculated (search step S ₅ ).

The values of Δα and Δβ are then displayed on means D (search step S ₆ ).

The operator looks at this display, and if the value is relatively large, the operator determines that the posture of the torch T will change significantly and there is a risk of interference with the workpiece WK, etc., and immediately selects one of the switches from the switch group SS.
Select and operate one or two axes. The computer 5 controls only the selected control axis.
The position information of point Pnmin is output as command position information (search step _S7 ). However, it is assumed that the moving speed at this time is a gentle speed that has been stored in advance. The operator operates each switch in the switch group SS while visually observing the movement of the torch T, and finally the torch T reaches the point Pnmin, which allows the operator to confirm the step of the user program that should be corrected. It is something.

After that, the operator can modify the parts that need to be modified in the desired step in the same manner as described above.

Although the above description has been made using a welding robot, the present invention can be similarly implemented in other types of robots such as cutting robots and assembly robots.

Since this invention is as described above, even if you do not know the number of the desired step, you can call the neighboring step by simply positioning the end effector in the vicinity, and the program can be corrected and corrected. It is something that can definitely be achieved and has a unique and remarkable effect.

[Brief explanation of drawings]

The drawings all show one embodiment of this invention, and the first embodiment is shown in the drawings.
The figure is an overall perspective view including a block diagram, and FIG. 2 is a flowchart. T...torch (end effector), 5...computer (control device), RO...industrial robot, _S1 ...(a) means, _S2 ...(b) means, _S3 ...(ha) ) means, S ₄ ... (d) means, S ₇ ... (e) means.

Claims (1)

[Claims] 1. A playback type industrial robot equipped with an end effector and whose relative position with respect to a workpiece is controlled by a control device, wherein the control device includes the following means: The industrial robot. (b) A means of determining whether there is a search command. (b) A means for fetching the current position information of each control axis of this industrial robot if there is a search command. (c) Means for calculating the deviation between each piece of positional information taught for playback and the current positional information. (d) Means for determining teaching position information with the least deviation. (e) Means for outputting teaching position information with the least deviation as command position information. 2. The industrial robot according to claim 1, wherein the deviation is inputted into a display means.