JPH03288209A - Off-line teaching system for handling robot - Google Patents

Abstract

PURPOSE:To simplify the off-line teaching of a handling robot by actuating a robot model combined with a work model, deciding that a robot holds a work based on the matching state secured between the data on the work and robot models, and storing these matched data. CONSTITUTION:A combination means 6 obtains the data on a 1st robot model including no work model and the data on a 2nd robot model kept in a state where the data on the shapes of the work model are connected to each other and the work model is combined with the 1st robot model in a single body. Meanwhile a means 6 decides that a work is held by a handling robot based on the matching state secured between the data on the 2nd robot model and the work models after actuating the combined 2nd robot model. Then the data obtained when a fact that the work is held by the robot is decided is stored as the teaching data. Thus the off-line teaching is simplified to the handling robot.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention displays a robot model and a workpiece model on an image output device, operates the robot model on the image output device, and obtains motion data of the handling robot. The present invention relates to an offline teaching system for handling robots.

[Background of the invention]

Today, robots are used in various fields including the manufacturing industry, contributing to production automation and labor savings.

Off-line teaching is preferable to online teaching in that the robots can be taught work operations without stopping the production line.

Examples of the above-mentioned offline teaching systems include Japanese Patent Application Laid-Open No. 61-113099 and Japanese Patent Application Laid-open No. 61-11.
The methods disclosed in Japanese Patent Application Laid-open No. 8081, Japanese Patent Application Laid-open No. 120029/1980, and the like have been proposed.

In the systems disclosed in the above-mentioned publications, motion data is taught by moving a point at the tip of the robot arm displayed on a CRT display and using this as a teaching point.

Therefore, the above system is suitable for a robot that is integrally equipped with a tool in place of the tip of the robot arm, for example, a robot that is equipped with tools such as a spray gun and a welding torch and performs work such as painting, sealing, and welding. hand,
This method is not suitable for handling robots used for moving or assembling elements separated from the robot body, ie, workpieces.

This is because, in the above-mentioned conventional technology, the concept of robot movement accompanying handling of a workpiece is not systematically realized.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a teaching system that can easily teach a handling robot off-line.

[Means to solve the problem]

In order to achieve the above object, the main means adopted by the present invention is to display a robot model and a workpiece model on an image output device, and operate the robot model on the image output device. In an off-line teaching system for a handling robot that creates motion data for a handling robot, a first robot model that does not include a workpiece model and data regarding the respective shapes of the workpiece model are combined, and the workpiece model is transferred to the first robot. The second one that is integrally combined with the model.
a combination means for obtaining data regarding a robot model;
The second robot model combined by the combination means is operated, and the data regarding the second robot model is consistent with the data regarding the workpiece model corresponding to the workpiece placed at an arbitrary position in the work space. This is an off-line teaching system for a handling robot, comprising: determining means for determining that the workpiece has been gripped by the handling robot.

[Effect]

In the off-line teaching system for a handling robot according to the present invention, first, a first
A second robot model in which the workpiece model is integrally combined with the first robot model by combining data regarding the respective shapes of the robot model and the workpiece model.
Data regarding the robot model is created. That is,
A workpiece is defined as a component of a handling robot.

Subsequently, the second robot model combined as described above is operated on the image output device, and the second robot model is operated on the image output device.
When the data regarding the robot model and the data regarding the workpiece model corresponding to the workpiece placed at an arbitrary position in the work space substantially match, it is determined that the workpiece has been gripped by the handling robot.

The data at this time is stored as teaching data (operation data).

[Examples] Examples embodying the present invention will be described below with reference to the accompanying drawings to provide an understanding of the present invention. It should be noted that the following examples are examples embodying the present invention, and are not intended to limit the technical scope of the present invention.

Here, FIG. 1 is an external view of an offline teaching system for a handling robot according to an embodiment of the present invention, FIG. 2 is a conceptual exploded perspective view of an example of the handling robot, and FIG. 3 is an illustration of the handling robot. This figure shows a schematic configuration of the constituent hands (a perspective view with the barrel disassembled).

Figure (b) is a perspective view of the assembled state, Figure (C) is a perspective view of the handling robot gripping a workpiece, and Figure 4 is a schematic configuration diagram of the handling robot gripping a workpiece. FIG. 5 is a flowchart schematically showing the processing procedure in the offline teaching system, and FIGS. 6 and 7 are schematic configuration diagrams of the handling robot for explaining motion teaching to the handling robot, respectively.

In FIG. 1, an offline teaching system 1 for the handling robot includes a digitizer 2 and a keyboard 3.
It basically consists of a CRT display 4 (image output device), a floppy disk device 5, and a computer 6.

From a hardware standpoint, these systems are similar to so-called personal computer systems (PCs) and do not have any unique components, so the burden on equipment is relatively small.

The offline teaching system 1 is a system that performs offline teaching when handling a workpiece, and includes:
Processing functions related to inputting work drawings.

■Processing functions related to robot and peripheral device input.

It has processing functions such as ■Processing function to create data related to robot motion teaching, ■Processing function related to motion simulation, ■Processing function related to teaching data output, and ■Processing function related to assistance.

Each of these processing functions is first displayed on the CRT display 4 as a processing menu, so that the operator can select it as desired.

Each of the above processing functions will be explained in sequence below.

■Processing function related to workpiece drawing input Workpiece drawing input processing is a process of inputting the shape of a workpiece using a drawing.

First, the operator sets the drawing of the workpiece on the digitizer 2, and the pen 2. Enter the line diagram by tracing the drawing with . For the process itself of inputting line diagrams from such drawings, techniques already known in the field of CAD and the like can be applied.

When three-dimensional views (plan, front, and side views) are input, Conhiutaro creates a three-dimensional surface model and converts it to C.
A three-sided view and a perspective view are displayed on the RT display 4.

While looking at the screen, if there is an input error, the operator inputs a command from the keyboard 3 to correct it, and after finally confirming that the displayed three-sided view and perspective view accurately represent the workpiece, the operator A command is input from the keyboard 3 and the work data is stored in a file.

■Processing functions related to robot and peripheral device input Processing of robot and peripheral device input is based on robot and workpiece dimensions (
coordinate data, etc.) and peripheral devices, the three-sided view and perspective view of the robot model (first robot model) and workpiece model are displayed on the CRT display 4.
displayed above.

Therefore, if there is a change in the dimensions of the robot or workpiece, the operator modifies the robot model or workpiece model on the CRT display 4 or inputs numerical values to represent the actual shape of the robot or workpiece.

When the input of data for the robot, workpiece, and peripheral devices is completed, the data is stored in a file.

■Processing function to create data related to robot motion teaching This processing function is the most characteristic element in the offline teaching system, and the outline of the processing procedure is as follows: Data regarding the shape of each of the workpiece models and the workpiece model are combined to create data regarding a second robot model in which the workpiece model is integrally combined with the first robot model. That is, the workpiece is defined as one component of the handling robot.

Subsequently, the second robot model combined as described above is operated on the CRT display 4, and data regarding the second robot model and the workpiece placed at an arbitrary position in the work space are displayed. When the data regarding the workpiece model substantially match, it is determined that the workpiece has been gripped by the handling robot.

The data at this time is stored in a file as teaching data (operation data).

Hereinafter, the points in the above configuration will be explained in detail based on FIGS. 2 to 4 and 6.

The meanings of the symbols given in each figure are as follows.

08: Origin 0 in the world coordinate system (within the work area)
1: Origin in robot coordinate system 1: Posture matrix of 6-axis coordinate system X7: Position vector W of 6-axis coordinate base origin: Workpiece posture matrix '1 in hand coordinate system. −: Position vector of the workpiece in the hand coordinate system H: Posture matrix of the hand coordinate system in the 6-axis coordinate system X, : Position vector of the hand coordinate system in the 6-axis coordinate system V so Workpiece posture matrix in the robot coordinate system ×
・To the position vector of the workpiece in the two-robot coordinate system : Posture matrix of the teaching point in the robot coordinate system F : Position vector of the teaching point in the robot coordinate system F : Posture matrix of the workpiece in the world coordinate system XP = World coordinates Position vector of the workpiece in the system: Posture matrix of the robot coordinate system in the world coordinate system Xr: Position vector of the robot coordinate system in the world coordinate system Here, l and X indicate the relative relationship between the robot and the workpiece. The data is preset by the processing function related to peripheral device input.

This teaching system uses Euler angles to represent posture.

Euler angles give rotations around the Z-axis, X-axis, and Y-axis of the coordinate system as α, β, and γ, respectively.

When used for actual posture calculation, use the following formula to calculate 3×
It is treated as a posture matrix of 3.

In this embodiment, the posture of the workpiece, the posture of the teaching point of the robot, etc. are all given by this method. Also, conversely, from the 3x3 posture matrix (α, β.

γ) can also be obtained.

In this example, Euler angles are used to display the attitude, but other methods include methods using direction cosines, roll angles, etc.
There are methods such as using pitch yaw.

The hand model is created by combining three-dimensional models input as single parts on the base coordinate system Oh of the hand (see FIGS. 2 and 3(a)). Each of the above parts has its own unique coordinate system, and during modeling, it is defined as a set of single models using data on the relative position and orientation between the hand's base coordinate system and the coordinate system of each part. be done.

These positional relationships are obtained by combining models on the CRT display 4.

In addition to the above data, the hand model also includes position data as seen from the hand base of the intermediate point A of the hand (this position data is expressed as (Xt, Yt, Zt)), which is treated as the robot's teaching point. has as numerical data.

(See Figure 3 Φ).

This is defined as a position vector Xc.

The workpiece to be handled is combined with the hand model defined as above.

Here, the position (X,,Y,,Z,) of the origin of the workpiece model coordinate system in the hand coordinate system, and the posture (α1゜β2.T8)
is set. Then, from (α0.β1°Tl-), W
is obtained.

That is, the workpiece is handled as a part of the parts that make up the hand, and its handling force is the same as that of the parts that make up the hand (see Figure 3 (C)).
.

Subsequently, the positional relationship in which the hand modeled as described above is connected to the tip of the robot's wrist (ie, the attachment portion of the hand) is defined.

This is (Xh, Yt, Zk), (rrh, L
.

rb). And (αh, βh + Tb
), 1 can be obtained.

Specifically, the modeling at this time is almost the same as when modeling the hand mentioned above, and the parts that make up the robot are assembled on the CRT display in the robot's base coordinate system. As one example, a hand model equipped with the workpiece defined as described above is assembled to the wrist tip (see FIG. 2).

As a result, a second robot model in which the work models are integrally combined is defined.

FIG. 4 shows the relationship between each data defined as described above and the position and posture of the robot (6 axes).

From the following relationship, the position and orientation of the workpiece coordinate system in the robot coordinate system is expressed as follows.

Also, the position of teaching point A is It is expressed as

Subsequently, based on FIG. 6, a procedure for creating teaching data for causing the handling robot to grip a workpiece will be described.

Operate the robot model with respect to workpiece model B placed in the work space (world coordinate system), and create workpiece model B' with the same shape as workpiece model B defined at the tip of the hand.
The positioning of the robot is performed by overlapping the images.

The matching state is checked based on the data of P and X, which are known at the stage when the workpiece is placed, and the data of F' and XF obtained from equation (2). That is, the state when each data overlaps is the posture required for handling.

Check the position of the handled workpiece in the world coordinate system (X, Y.

2,') and posture (α, , β, , γ#) are calculated using the following equation 0, and the robot model is machined until these are satisfied.

Note that the above ε indicates an allowable error.

As an example, in the case of a robot whose motion data is riθ, ~θ, (ii) the position vector of the hand tip and the posture based on the Euler angle. We will discuss the case of a robot that uses data as motion data.

(1) In the case of a robot whose motion data is θ1 to θ, let P be the position vector of the workpiece when the equation 0 is satisfied, and the x-posture matrix.

P' = R-V 4-l-11-1-W' Yo? )M
=c, p:w"-+-1f", .

x,′=xr+B −L =X,+L(χ,+t”L
Xi +t$)44. )Yorin-I((x,' -Suatsu-H-xni-H゛日°X-
/...■Here, in general, the value θ of each axis of the robot is calculated from the position vector of the tip of the robot's six axes and the posture matrix H.
.

Since the method for calculating ~θ is well known, θ from formulas ■ and ■
1 to θ are found.

(ii) In the case of a robot whose motion data is the position vector of the hand tip and posture data based on Euler angles, P' = 4--H-W = 4-A-Harihachi = 62-P゛-Wl...・■ Since the method of determining Euler angles from a 3×3 attitude matrix is publicly known, Euler angles can be obtained from equation 0.

Also, from the 0.0 formula, 4. Since the eyes are determined, Xl is better than the 0 formula.
is obtained.

Next, we will discuss how to solve the following problems that occur with other methods as described above.

■When multiple workpieces of the same shape are arranged, which workpiece should be compared with the coordinate system of the workpiece model?

■As a modified example, if multiple types of workpieces are defined for one hand, which workpiece should be compared?

The above problem can be solved as follows.

Compare and check each point data of the handled work model and the placed work model.

That is, in terms of how the shape is defined when modeling a workpiece, since the workpiece defined for the hand and the workpiece placed to be handled are the same, their data should match.

Therefore, the matching state of the two works is checked by comparing the data regarding each point constituting the two works.

For example, in case (2) above, the work closest to the origin of the work model defined in the hand model is selected first, and the above check is performed on that work. In addition, in the case (2) above, it can be handled by checking the origin of each of the work models defined in the hand model and performing the above check.

Since the gripping state of the workpiece handled by the handling robot is confirmed in the above-described manner, this system does not require any further instruction to confirm the gripping state of the workpiece.

■Processing functions related to motion simulation In motion simulation processing, the handling work is shown using animation based on the data set so far.

That is, in FIG. 7, when reproducing a program that is taught to handle workpiece C, first, the robot model is operated according to the teaching data up to the teaching point at which the workpiece C is to be handled. At this time,
The work C above has not been handled yet, so
The part of the workpiece in the robot model is not displayed (
stomach).

If the robot model is moved to a position where it can handle the workpiece C, and the hand close data is set, check whether the workpiece to be handled is placed in that area when the hand is closed. After checking,
The workpiece model is displayed at the tip of the robot model,
The work model that has been placed in advance is deleted (see below).

Furthermore, operate the robot model according to the teaching data,
When the robot model moves to the teaching position where the hand open signal is set, the workpiece model being handled by the robot model is erased, and a new workpiece model appears on the workpiece coordinate system (c, 2).

In the above process, the robot's operating range is automatically checked, and if the operating range is exceeded, which arm of the robot is outside the operating range is displayed in a way that allows identification.

The operator can pause the robot's arm or hand at any point during the simulation, magnify a part of the image, or change the viewpoint to avoid interference between the robot's arm or hand and other workpieces, as well as the position and You can check your posture, etc.

If there is a part that exceeds the robot's range of motion, if there is interference with the robot, or if there is any other undesirable behavior, the simulation process will be stopped at that point.
Data can be corrected.

Then, by performing a motion simulation while making the above modifications, it is possible to complete motion data for handling a workpiece extremely easily, with the feeling of remote teaching.

If satisfactory results are obtained through motion simulation,
Store the data in a file.

■Processing related to teaching data output! The ability teaching data output process is a process in which preferred data obtained as a result of motion simulation is edited into teaching data and output.

The most preferable output means is to send the data directly to the teaching data bath of the handling robot through a transmission line.

The handling robot stores the sent teaching data through interrupt processing, so it does not interfere with work on the workpiece.

Alternatively, the information may be output to a medium such as a cassette tape or a floppy disk, and the handling robot may read the cassette tape or floppy disk.

The teaching data is then stored in a file.

■Auxiliary processing functions Auxiliary processing includes data diskette initialization processing and XY
It performs auxiliary processing such as displaying the screen itself on the CRT display 4 on a plotter.

The processing procedure of this system configured as described above is schematically shown in FIG.

That is, (1) Work modeling The work to be handled is modeled. The above workpiece has a coordinate system (origin) in input units,
The three-dimensional data of each point is a value in this coordinate system.

■Work placement Place the input work model in the work space. Work placement in this case means setting the relative positional relationship between the coordinate system (world coordinate system) in the work space and the coordinate system of each work model.

■Hand modeling The hand part is modeled. Furthermore, X-ren is set.

■The correspondence between the hand and the workpiece defines the relative relationship between the hand model and the workpiece model. That is, the workpiece is defined as one component of the hand. Here, Me and W are set.

■The correspondence between the robot model and the hand model is set by how the hand model is attached to the tip of the robot model.

Here, M and H are set.

(2) Operation teaching The hand model and robot model defined as above are called up on the CRT display, and the robot model is operated by superimposing the handled work model on the placed work model.

When the hand is set to close, the alignment state of the workpiece model is checked, and if it is within the tolerance, the posture of the robot model at that time is stored as teaching data for the handling robot. Thereafter, teaching data is created by moving the robot model to a desired position to move the workpiece.

■Operation simulation Based on the teaching data set as above, CR
A simulation is performed on the T-display 4.

Since the teaching system according to this embodiment is configured as described above, offline teaching to the handling robot can be extremely easily performed.

In addition, since teaching errors can be easily discovered and corrected by motion simulation, the quality of teaching can be improved and work efficiency can also be improved.

〔Effect of the invention〕

As described above, the present invention provides an off-line teaching system for a handling robot that displays a robot model and a workpiece model on an image output device, and operates the robot model on the image output device to create motion data for the handling robot. , the first one that does not include the work model
combining means for combining data regarding the respective shapes of the robot model and the workpiece model to obtain data regarding a second robot model in which the workpiece model is integrally combined with the first robot model; The second robot models combined by the combination means are operated, and the data on the second robot models are matched with the data on the workpiece model corresponding to the workpiece placed at an arbitrary position in the work space. Since this offline teaching system for a handling robot is characterized by comprising a determining means for determining that the workpiece is gripped by the handling robot, it is possible to extremely easily perform offline teaching to the handling robot.

[Explanation of symbols]

1...Offline teaching system 2...Digitizer 3...Keyboard 4...CRT display (II image output device) 5...
・Floppy disk device 6...computer

Claims (1)

[Claims] 1. In an off-line teaching system for a handling robot, which displays a robot model and a workpiece model on an image output device, and operates the robot model on the image output device to create motion data for the handling robot. , a first robot model that does not include a workpiece model and data regarding the respective shapes of the workpiece model are combined, and the workpiece model is integrally combined with the first robot model. a combining means for obtaining data; operating the second robot model combined by the combining means; and a workpiece corresponding to the data regarding the second robot model and the workpiece placed at an arbitrary position in the work space. 1. An offline teaching system for a handling robot, comprising determining means for determining that the workpiece has been gripped by the handling robot based on a state of consistency with data regarding the model.