JPH06105413B2 - Teaching method for industrial robot - Google Patents

Description

The present invention relates to a robot teaching method, and more specifically, to teaching of a robot adapted to convert teaching data obtained off-line into a virtual position and correct it online. Regarding the method. This is used in the technical field where offline teaching data is transferred to a robot installed in a production line to reproduce a predetermined operation.

[Prior art]

Off-line teaching, which has recently attracted attention as a teaching method for industrial robots, teaches a target position of a work object (hereinafter, line work) directly to a robot (hereinafter, line robot) installed on a production line. Instead, the teaching is provided separately from the production line by using the same robot (hereinafter, model robot) and work (hereinafter, model work) separately. The teaching data is converted and transferred to the line robot,
The line robot can reproduce the operation for a predetermined line work. An example of the teaching system will be described. As shown in FIG. 4, the model robot 1, the line robot 2, and the conversion processing device 3 are provided.
And model work 4. For example, when this off-line teaching system is adopted for spot welding work of an automobile body, the wrist of the model robot 1 is sequentially taught to the model 4 which is the same as the line body so as to follow the target position which is the welding point. . In the conversion processing device 3, data taught offline from the position information of three points corresponding to the model work 4 and the line work 5 taught separately to the model robot 1 and the line robot 2 (hereinafter referred to as teaching data). Since the conversion formula for converting the reproduction data on the production line (hereinafter, referred to as online data) is calculated, the teaching data is online data coordinate-converted using the conversion formula. If this is transferred to the line robot 2, the line robot 2 reproduces the operation of tracing a predetermined target position with respect to the line work 5.

By doing this, while the line robot is performing the current work, it is possible to teach different workpieces offline using the same model robot, so it is necessary to stop the line for a long time for teaching. Instead, it is possible to reduce the time that does not directly contribute to production.

According to the system described above, the reproduction operation should be as taught to the model robot, but in reality, the target position to be ideally converted and the reproduction position after conversion should be determined by the following causes. Makes a slight difference. The causes are that there are variations in work accuracy, that there are variations in the machine dimensions of the robot, that the same robot is not mechanically symmetrical in the front-rear, left-right, and up-down directions, and that the mounting surfaces of the robot and work are uneven. , There is an error in the calculation, and the actual machine dimensions and the dimensions of the in-computer model do not match. As a result, for example, the position of the gun for spot welding attached to the tip of the wrist of the robot collides with the line work, which is different from the ideally calculated position. It will also damage the. Such a problem is not limited to spot welding work, but becomes a problem where extremely high reproducibility is required in handling work and assembling work.

To completely eliminate such a conversion error depends on how to suppress the mechanical error during the conversion process and how to make a model having the mechanical error by a computer. In addition, the solution cannot be solved unless the calculation error due to the digit cancellation of the digital calculation in the conversion processing is eliminated. However, in reality, these are extremely difficult, and even if they are realized, the calculation time for conversion becomes long, which causes a problem in reproducing the operation of the robot, and a problem remains.

[Object of the Invention] The present invention has been made in view of the above problems, and an object of the present invention is to enable the line robot to accurately reproduce the data taught offline in the model robot. The error that occurs during data conversion can be absorbed by online teaching,
It is an object of the present invention to provide a teaching method for an industrial robot that realizes off-line teaching.

[Structure of Invention]

The features of the teaching method of the industrial robot according to the present invention will be described with reference to FIGS. 1 and 3. The data a1, a2, a3 ...
Virtual positions corresponding to a1 ″, a2 ″, a3 ″ ...
a1 ′, a2 ′, a3 ′ ... and its virtual positions a1 ′, a2 ′,
By instructing the line robot 2 from the target positions a1 ", a2", a3 "on the line work 5 online, the line robot 2 causes the line robot 2 to target positions a1", a2 ", a3" ..
That is, it is possible to perform a predetermined operation of tracing.

〔Example〕

The teaching method of the present invention will be described below with reference to the drawings. FIG. 2 is a system diagram for realizing the invention, in which a model robot 1 of the same model as the line robot 2 is installed at a place off the production line, and is the same model as the line work 5 to be operated on the production line. The operation for the work 4 is taught. A conversion processing device 3 calculates a conversion formula for converting teaching data into online data from position information of three points corresponding to each of the model work 4 and the line work 5 taught by the model robot 1 and the line robot 2. In addition, using the conversion formula, the data a1 and a1 taught offline shown in FIG.
2, a3 .. is used to calculate the online position data a1 ″, a2 ″, a3 ″ ... at the target position on the line work shown in FIG. 1. 6 is a target position separating device, which performs conversion processing. Device 3
When the teaching data is converted, by giving a certain conversion parameter, a new virtual position a1 ′, a2 which is intentionally slightly displaced from the original target position, that is, the position where the wrist of the line robot 2 should follow in the specified direction. ′, A3 ′ ·· is calculated. A movement control device 7 is a control device having a teaching step feed mode for moving from a virtual position to a target position. This is because when the line robot 2 is taught online from the virtual positions a1 ', a2', a3 '... Separated from the line work 5 to the target positions a1 ", a2", a3 ".. Therefore, even if there is an error in the calculated virtual position, it is taught that the position should be used as a base point to absorb the error online. 3, the target position separating device 6, and the movement control device 7 are integrated as needed, and are configured by appropriately combining, for example, a personal computer.

Next, the teaching operation and its conversion and reproduction will be described step by step.

First, the model robot 1 and the model work 4 are arranged so as to be somewhat similar to the line robot 2 and the line work 5 installed on the production line. The operator guides the wrist of the model robot 1 to move the work point on the model work 4 to the third position.
.. are taught in sequence as shown in the figure, such as a1, a2, a3. The data is the conversion processing device 3
Is input to the teaching data, the teaching data is converted into data to be reproduced on the production line using the conversion formula as described above. At that time, the target position separating device 6 gives a certain conversion parameter to intentionally convert the data into the original target positions a1 ″, a2 ″, a3 ″.
.. is instructed to calculate virtual positions a1 ', a2', a3 '.. Since this virtual position involves an error in conversion,
As shown in FIG. 1, the target position a1 ″, a on the line work 5
The positions are not displaced to the same extent with respect to 2 ″, a3 ″ ..., but the displacement amounts are partially different. Therefore, the line robot 2 is set to the virtual position a with respect to the line work 5.
1 ', a2', a3 '... Target position a1 ″, a2 ″, a
When the operator teaches 3 ″ ·· online by guiding the tool 8 attached to the wrist in the direction of arrow 9,
The movement amounts b1, b2, b3, ... From the virtual position are recorded for each position. Since these are stored in the line robot 2 as a calculated movement amount for shifting from the virtual position to each target position, the line robot 2 always stores information for sequentially tracing the target positions. The teaching of each position is carried out in a very short time by stepwise feeding. Moreover, the online teaching is only for the first linework 5 on which the line robot 2 works, and the wrist directly follows the target position from the next linework based on the stored data. Then, a predetermined work is performed.

A series of the above-mentioned teaching work until the virtual position is calculated is performed off-line, and does not hinder the work of the robot on the production line. Teaching from the virtual position to the target position is performed online, but the time required for that is extremely short compared to the time required for all the teaching work that was conventionally done online, and the teaching work of the robot is It is possible to realize speeding up. Moreover, since the reproducibility is high, which cannot be obtained by the offline teaching that has been conventionally considered, it is possible to perform the offline teaching itself which is in a situation that cannot be realized. The model robot and model work described above may be model systems created in an electronic computer.

〔The invention's effect〕

As described in detail above, the teaching method for the industrial robot of the present invention converts the data taught offline into a virtual position corresponding to the target position on the linework, and the linework is converted to the linework from the virtual position. Since the upper target position is taught online, the reproducibility of the motion of the line robot following the target position is kept extremely high. Therefore, it is avoided that the wrist collides with a part of the line work or damages the line work during the reproduction operation of the line robot. Further, although the teaching work is performed both offline and online, the time of online teaching that hinders production can be significantly shortened.

[Brief description of drawings]

FIG. 1 is an explanatory view of a teaching procedure in a line robot in a teaching method for an industrial robot of the present invention, FIG. 2 is a teaching system diagram for realizing the method, and FIG. 3 is an offline teaching using a model work. An explanatory diagram and FIG. 4 are system diagrams of conventionally considered offline teaching. 1 …… Model robot, 2 …… Line robot, 4 ……
Model work, 5 ... Line work, a1, a2, a3 ...
Teaching data, a1 ', a2', a3 '... Virtual position, a1 ", a
2 ″, a3 ″ ... Target position.

Front page continuation (72) Inventor Hideyuki Higuchi 1-1 Kawasaki-cho, Akashi-shi, Hyogo Kawasaki Heavy Industries Ltd. Akashi factory (56) Reference JP-A-57-69315 (JP, A) JP-A-57-182205 (JP, A) JP 59-50971 (JP, A) JP 58-192107 (JP, A) JP 58-58607 (JP, A) JP 58-14205 (JP, A)

Claims (1)

[Claims] 1. A method of teaching a robot by off-line teaching, comprising: teaching a model robot using a model work, and then causing the line robot to reproduce a predetermined operation for the line work based on the teaching data. The converted data is converted into a virtual position that corresponds to the target position on the line work but is slightly displaced, and by teaching the line robot the target position online from the virtual position, the line robot can determine the target position. A method for teaching an industrial robot, characterized in that a predetermined operation to be followed can be performed.