JP2001100834A - Device and method for preparing robot teaching data - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method capable of preparing teaching data high in precision through computer simulation. SOLUTION: In this method for preparing robot teaching data, when robot teaching data prepared by simulation are inputted to a real machine, the robot teaching data during preparation is corrected by simulation, based on the correction result at correcting of these robot teaching data by using this real machine.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an apparatus and a method for creating robot teaching data by computer simulation.

[0002]

2. Description of the Related Art In recent years, robot teaching data (hereinafter, simply referred to as teaching data) for causing a robot to perform a predetermined operation has been created by computer simulation. Creation of teaching data by computer simulation is performed by operating a robot graphically displayed on a display in the same manner as in actual work. Therefore, it is safe to perform any operation on the robot displayed as a graphic, and the teaching data can be created much faster than the teaching by the actual machine. The creation of teaching data by computer simulation is referred to as offline teaching.

FIG. 6 is a flowchart showing a procedure of a conventional offline teaching.

[0004] Conventional off-line teaching, first,
The data of the robot to be taught, the data of the work to be performed, the layout data of the work site, and the like are captured (S101), and subsequently, the touch-up data by the actual machine is captured (S102). The touch-up data sets the pin at the same position as the working point and performs the operation of contacting the end effector tip of the actual robot with this pin from several directions with respect to the pin. This is to acquire the position data of each axis of the robot.

Subsequently, the robot is calibrated by simulation based on the acquired data (S103). In this calibration, the position of the simulation robot is corrected by comparing the position data of each axis on the actual machine with the position data of each axis of the simulation robot by setting the simulation robot to the same posture as when the touch-up data was acquired. It is what you do.

[0006] The calibration of the touch-up data creation and simulation by the actual machine is performed when the actual robot deflects due to its own weight or the weight of the end effector and the position is slightly shifted due to the deflection. This is a process for reproducing with a robot by simulation.

After the calibration is completed, teaching data for actually performing the work is created by simulation (S104). This involves simulating a work by moving a robot graphically displayed on a display, and storing an operation path, a work point, a work instruction, and the like at that time as teaching data.

[0008] The completed teaching data is input to an actual machine, and the operation of the actual machine is checked. FIG. 7 is a flowchart showing a procedure for confirming the operation in the actual device.

First, the teaching data is input (loaded) to an actual machine (S201). Subsequently, the loaded teaching data is reproduced, and the robot is actually operated (S202). If there is an error between the contact teaching point of the operation result and the actual contact point (S203, Yes),
This error is corrected by the actual machine (S204), and the corrected teaching data is overwritten on the loaded teaching data.
Finally, the teaching data is set so that the actual machine can work (S205). Then, it is determined whether or not the correction of the error has been completed for all the working points (S206). with this,
Complete teaching data is completed.

[0010]

By the way, in the offline teaching, it is ideal that the correction work by the actual machine is not required. However, in reality, it is rare that “No” is determined in step S203, and in most cases, it is necessary to correct the teaching data by the actual machine.

In a simulation of a robot, deflections and displacements of various parts which occur when the robot takes various postures are normally calculated and reproduced from the weight of each part of the robot. However, slight bending or misalignment that occurs in an actual machine cannot be completely reproduced only by calculation. For this reason, in offline teaching, it is necessary to create and calibrate touch-up data on the actual device as described above. Then, by performing many touch-up data creations and calibrations, it is possible to reduce the error correction after the offline teaching.

However, since the creation of touch-up data is an operation on a real machine, the more points that are acquired, the more
The operation time of the actual machine becomes longer, and the effect of offline teaching is lost. Further, when the end effector is heavy, there is a problem that the error is reduced in the posture in which the touch-up data is created, but the error is not reduced in other postures.

Accordingly, an object of the present invention is to create teaching data that can create more accurate teaching data without creating touch-up data or performing calibration with an actual machine in creating teaching data by computer simulation. It is to provide an apparatus and a method thereof.

[0014]

The present invention is achieved by the following means.

(1) An apparatus for creating robot teaching data by computer simulation, wherein the simulation means creates the robot teaching data by reproducing the operation of the robot by computer simulation. Storage means for storing the robot teaching data; of the robot teaching data stored in the storage means, input robot teaching data already input to the actual machine; and an actual robot based on the input robot teaching data. The difference data calculation means for comparing the actual robot teaching data used for the operation and calculating the difference data between the two, and the simulation means creates the difference data based on the difference data calculated by the difference data calculation means. Correction means for correcting robot teaching data , Creation apparatus for a robot teaching data and having a.

(2) For each teaching point of the robot teaching data created by the simulation means, the correcting means corrects with the closest point, that is, the difference data of the closest point in view of not only the distance but also the angle difference. It is characterized.

(3) A method for creating robot teaching data by computer simulation, wherein the operation of the robot is reproduced by computer simulation to create robot teaching data;
The robot teaching data created by computer simulation and input to the actual machine is compared with the actual robot teaching data used for operating the actual machine based on the input robot teaching data, and the difference data between the two is calculated. A method for creating robot teaching data, comprising: calculating, and correcting robot teaching data created by the simulation based on the calculated difference data.

(4) The step of correcting the robot teaching data includes the step of correcting the closest point for each teaching point of the robot teaching data created by the simulation, that is, the difference between the closest points not only in terms of distance but also angle difference. The correction is performed using data.

(5) A method for creating robot teaching data by computer simulation, wherein when robot teaching data already created by simulation is input to an actual machine, the robot teaching data is converted using the actual machine. A method for creating robot teaching data, wherein the robot teaching data obtained by the simulation being created is corrected based on the correction results at the time of the correction.

[0020]

According to the first aspect of the present invention, the difference data calculating means compares the robot teaching data already created by the simulation with the teaching data of the robot actually operated using the teaching data. By comparing and obtaining the difference data between them, the correction amount of the robot teaching data performed in the actual machine can be obtained. Then, since the correction means corrects the robot teaching data created by the simulation means based on the difference data, the correction means corrects a subtle positional shift generated in the actual robot due to the weight of the robot or the weight of the end effector. be able to. Therefore, more accurate robot teaching data can be created only by simulation.

According to the second aspect of the present invention, the correction means is arranged so that, for each teaching point of the robot teaching data created by the simulation means, the closest point, that is, the closest point in view of not only the distance but also the angle difference. By the point difference data,
Since the created teaching data is corrected, the correction is performed for each teaching point at a position where the robot posture of the actual machine and the robot posture in the simulation are substantially the same. Therefore, highly accurate correction according to the actual operation position of the robot becomes possible.

According to the third aspect of the present invention, the robot teaching data already created by the simulation,
The amount of correction of the robot teaching data performed in the actual machine can be obtained by comparing the teaching data of the robot actually operated using the teaching data and calculating the difference data between the two. Then, since the robot teaching data created by the simulation is corrected based on the difference data, it is possible to correct a subtle positional shift generated in the actual robot due to the weight of the robot, the weight of the end effector, and the like. Therefore, more accurate robot teaching data can be created only by simulation.

According to the fourth aspect of the present invention, for each teaching point of the robot teaching data created by the simulation, the closest point, that is, the difference data of the closest point by not only the distance but also the angle difference, is used. Since the created teaching data is corrected, the correction is performed for each teaching point at a position where the robot posture of the actual machine and the robot posture in the simulation are substantially the same. Therefore, highly accurate correction according to the actual operation position of the robot becomes possible.

According to the fifth aspect of the present invention, when the robot teaching data created by simulation, which has already been created, is input to the actual machine, the correction results obtained when the robot teaching data is modified using the actual machine are used. , The robot teaching data by the simulation being created is corrected, so the actual robot can correct subtle positional deviations caused by its own weight, the weight of the end effector, etc. Data can be created only by simulation.

[0025]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
An embodiment of the present invention will be described.

FIG. 1 is a functional block diagram for explaining a robot teaching data creating apparatus to which the present invention is applied.

This apparatus stores a simulation unit 11 for creating teaching data by a predetermined simulation program, and CAD data (for example, robot data, work data, work site layout data, etc.) of a work required for the simulation. It comprises a CAD data storage section 12, a primary teaching data storage section 13 storing primary teaching data (details will be described later), and a real machine teaching data storage section 14 storing teaching data used in a real machine.

In FIG. 1, for the purpose of understanding the present invention,
Although the apparatus configuration is shown as being blocked by its function, such an apparatus is actually implemented by a computer called an engineering workstation (EWS) or the like. Therefore, the simulation unit 11
Is executed by the EWS executing a simulation program necessary for creating teaching data. The storage units 12, 13, and 14 are, for example, hard disks or other storage media built in or connected to the EWS.

FIG. 2 is a flowchart showing a procedure for creating teaching data to which the present invention is applied.

First, the simulation unit 11 executes the CAD
From the data storage unit 12, data of the robot to be taught
The data of the work on which the robot works and the layout data of the work site are acquired (S1).

Subsequently, the teaching data for performing the work on the work is created (S2). This is performed by moving the robot graphically displayed on a display (not shown) by the operation of the simulation unit 11 in the same manner as conventionally performed. Thereby, the movement of the path and each axis at that time, the work start point and the shading point, the contact teaching point at which the work and the end effector come into contact with each other, and the work instruction (for example, the opening and closing operation of the robot hand and the welding gun, etc. Command)
And primary teaching data is created.

The created primary teaching data is stored in the primary teaching data storage unit 13 as the primary teaching data being created (S3).

Subsequently, the previously created primary teaching data (input teaching data) that has been created before is read from the primary teaching data storage unit 13, and the actual operation is performed based on the primary teaching data. The teaching data of the robot is read from the actual machine teaching data storage unit 14, and the difference data between them is calculated (S4). The created primary teaching data used at this time is teaching data for a robot of the same type as the robot for which the teaching data currently being created is to be processed, and an end effector of the robot having the same type is mounted. Use teaching data. More preferably,
It is preferable that the robots are exactly the same and have the same end effector.

The difference data calculated here is obtained by comparing the primary teaching data with the actual teaching data for each target coordinate value at the contact teaching point (the contact point between the work and the end effector tip). It is.

FIG. 3A is a table showing target coordinate values and direction cosine for each contacted teaching point in the prepared primary teaching data, and FIG. 3B is a table showing target coordinate values and direction cosine for each contacted teaching point in the actual machine teaching data. It is a chart. Comparing the two shows that there is a difference in the target coordinate value of each contact teaching point. This difference corresponds to the correction amount corrected by the actual machine in the conventional offline teaching. FIG.
C is difference data calculated from FIGS. 3A and 3B.

After calculating the difference data, the primary teaching data being created is corrected based on the difference data (S5).
At this time, the difference data is applied when the target coordinate value of the contact teaching point is close to the direction cosine (that is, the direction cosine in the Z direction of the coordinate system of the end effector, for example). Compare the angle to and select the closest one.

The teaching data for which the difference data has been calculated is basically different from the teaching data being created. Therefore,
If the contact teaching points are as close as possible and the direction cosine is also close, the posture of the robot is almost the same. If the postures of the robots are almost the same, it may be considered that the bending, the displacement and the like applied to the robot at that time are the same. Therefore, if the difference is closer to each other, by using the difference data for the correction, it is possible to correct a subtle shift that is difficult to obtain by the simulation calculation, such as the bending of the robot.

The extent to which the distance between the contact teaching point in the difference data and the contact teaching point in the teaching data being created can be applied depends on the weight of the robot, the weight of the end effector, and the like. I can't decide. Therefore, the applicable distance is determined from the actual value of the created experiment or teaching data.

When the correction is completed, this is output as the final teaching data (S6), and the process ends.

FIG. 4 shows a specific example. FIG.
FIG. 4B is a table showing target coordinate values and direction cosine for each contact teaching point in the next teaching data, and FIG. 4B shows each contact teaching point in the final teaching data corrected by the difference data (see FIG. 3C) calculated in step S4. 3 is a table showing target coordinate values and direction cosines. As shown in the figure, in the final teaching data, the target coordinate value of each contact teaching point is corrected by the difference data.

The completed final teaching data is input to the actual machine. Then, as in the conventional case, according to the procedure shown in FIG.
Confirmation work by the actual machine is performed. At this time, since the final teaching data according to the present embodiment has been corrected by substantially the same data as the data corrected by the actual machine, the error has a very small value, and the correction work is hardly required. That is, in step S203 in FIG. 7, there is no error at most of the contact teaching points. In addition, in the present embodiment, since it is possible to omit operations such as taking touch-up data and performing calibration before creating teaching data, the teaching data can be created faster accordingly.

In the present embodiment, as described above, difference data is calculated from the created teaching data and the teaching data for operating the actual machine, and furthermore, the data is that of a robot of the same model. Is required. This is because different models have different weights of the robot, so that the bending of each part of the robot is completely different. Similarly, when the end effector is different, the bending or displacement occurring differs depending on the weight of the end effector. Therefore, it is necessary that the end effector be the same or at least have the same weight.

However, there is a case where the teaching data does not exist by such the same kind of robot. In other words, this is a case where teaching data for a robot is completely newly created. In such a case, the difference data cannot be calculated in step S4 described above.

Therefore, in the present embodiment, when there is no created teaching data, about three points of teaching data are created and corrected by an actual machine, so that data for calculating difference data is obtained. I decided to create it.

FIG. 5 is a flowchart showing the procedure for this.

First, CAD data of a work and a robot is obtained (S11).

Subsequently, about three contact teaching points on the work are selected, and the operation of the robot at those points is taught by simulation (S12). Here, for example, in the case of a robot performing welding, three points having different postures are selected.
The points are the first, middle, and last of three points or a plurality of welding points (which are contact teaching points) at positions far from each other. Thus, the actual welding posture can be represented.

The created teaching data is stored in the primary teaching data storage unit 12 (S13). This is the created primary teaching data.

Subsequently, the created teaching data is input to the actual machine to correct the error at each point (S14). Then, the corrected actual machine teaching data is stored in the actual machine teaching data storage unit 1.
4 (S15).

As described above, since the respective data for calculating the difference data are prepared, if the teaching data is created in accordance with the procedure shown in FIG. Teaching data with less data can be completed.

Although the embodiment to which the present invention is applied has been described, the present invention is not limited to such an embodiment. For example, the primary teaching data is created by conventional off-line teaching and then corrected by the difference data, thereby making it possible to significantly reduce correction work by the actual machine. Further, as for the created teaching data used for calculating the difference data, the use of existing data reduces the number of newly created teaching data, and the present invention can be used effectively.

[Brief description of the drawings]

FIG. 1 is a functional block diagram of a robot teaching data creation device to which the present invention is applied.

FIG. 2 is a flowchart showing a procedure for creating robot teaching data according to the present invention.

FIG. 3A is a table showing target coordinate values and direction cosine for each contact teaching point in created primary teaching data, and FIG. 3B is a table showing target coordinate values and direction cosine for each contact teaching point in actual machine teaching data. FIG. 3C is a chart showing difference data.

FIG. 4A is a table showing target coordinate values and direction cosine for each contact teaching point in primary teaching data before correction, and FIG. 4B is a table showing target coordinates for each contact teaching point in final corrected teaching data. It is a chart which shows a coordinate value and a direction cosine.

FIG. 5 is a flowchart showing a procedure for creating data for calculating difference data when there is no created teaching data.

FIG. 6 is a flowchart showing a procedure for creating robot teaching data by a conventional simulation.

FIG. 7 is a flowchart showing a procedure for confirming the operation of robot teaching data on a real machine.

[Explanation of symbols]

 Reference Signs List 11 simulation unit 12 CAD data storage unit 13 primary teaching data storage unit 14 actual machine teaching data storage unit

Claims (5)

[Claims] 1. An apparatus for creating robot teaching data by computer simulation, comprising: a simulation unit that creates robot teaching data by reproducing an operation of the robot by computer simulation; and a robot created by the simulation unit. Storage means for storing the teaching data; of the robot teaching data stored in the storage means, the input robot teaching data already input to the actual machine; and the actual robot based on the input robot teaching data. Difference data calculating means for comparing the actual robot teaching data used for the operation and calculating the difference data between the two, and a robot created by the simulation means based on the difference data calculated by the difference data calculating means Correction means for correcting the teaching data; Creating apparatus of the robot teaching data and having a. 2. The robot teaching data creating apparatus according to claim 1, wherein the correcting means performs correction for each teaching point of the robot teaching data created by the simulation means using difference data of a closest point. . 3. A method for creating robot teaching data by computer simulation, comprising the steps of: creating a robot teaching data by reproducing an operation of a robot by computer simulation; Comparing the input robot teaching data with the actual robot teaching data used to operate the actual machine based on the input robot teaching data, and calculating difference data between the two; Correcting the robot teaching data created by the simulation based on the obtained difference data. 4. The method according to claim 3, wherein in the step of correcting the robot teaching data, for each teaching point of the robot teaching data created by the simulation, the correction is performed using difference data of the closest point. How to create robot teaching data. 5. A method for creating robot teaching data by computer simulation, wherein when robot teaching data created by simulation is input to an actual machine, the robot teaching data is corrected using the actual machine. A method for creating robot teaching data, wherein the robot teaching data obtained by the simulation being created is corrected based on the correction results at the time of the execution.