JP3083706B2 - Error detection method for offline teaching data - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method that is performed between a work position of a work robot and a work object when the work robot is operated in accordance with teaching data of the work robot created using a CAD system. The present invention relates to a method for detecting an error in offline teaching data for detecting an error.

[0002]

2. Description of the Related Art For example, when teaching is performed by directly operating a work robot installed on a production line, an operator who is familiar with the operation of the work robot must perform work on the production line. The work becomes inefficient. In addition, since the work needs to be performed in a state where the production line is stopped, the operation rate of the production line also decreases.

Therefore, in the working robot, offline teaching is widely performed in order to increase the efficiency of the teaching work or maintain the operation rate of the manufacturing line. That is, if a model of a work robot and a work object is constructed on a computer, teaching data is created using the model, and the teaching data is supplied to a work robot at the site, the teaching data can be created. It is not necessary to stop the production line immediately, and the teaching work becomes easy.

When teaching data created using such an off-line teaching device is downloaded to a working robot on a manufacturing line, an installation error of the working robot and a structural error of the working robot (which occur during assembly). The work point of the work object and the work point of the work robot (hereinafter referred to as TCP (Tool Center Point)) may be caused by various factors such as an error, a setting error of the joint sensor, etc. That)
It is inevitable that there will be a gap between them. This shift is corrected by the operator operating the work robot at the site.

[0005] Here, the deviation amount of the TCP of the work robot is used to correct the teaching data incorrectly or to efficiently convert the teaching data in response to a change in the work object processed by the same work robot. Must be reflected in the offline teaching device.

Therefore, a method is generally used in which the teaching data corrected in the manufacturing line is uploaded to an offline teaching device and compared with the teaching data before correction to detect the deviation amount.

[0007]

However, it is difficult for an operator to correctly grasp the deviation amount when reproducing the teaching data on an offline teaching device by simply uploading the corrected teaching data. .

That is, as shown in FIGS. 5A to 5D,
When the teaching data (FIG. 5A) created by matching the work point (indicated by X) of the work target and the TCP (indicated by ○) of the work robot R on the offline teaching device is downloaded to the work robot R at the site It is assumed that a deviation ΔK has occurred between the working point and the TCP (FIG. 5).
B). Therefore, the operator at the site checks the T
The CP is corrected to match the working point (FIG. 5C), and the corrected teaching data is uploaded to the offline teaching device. In the offline teaching device, the position of the work point of the work target is the same as that in FIG. 5A. Therefore, when the corrected teaching data is displayed, the relationship between the work point and the TCP of the work robot R is as shown in FIG. 5D. Become. In this case, since the actual positional relationship between the work object and the work robot R at the site is the state shown in FIG. 5B, it differs from the state on the offline teaching device shown in FIG. 5D. Therefore, the operator may erroneously recognize the state of the site, which adversely affects operations such as correction and change of teaching data.

On the other hand, in view of the above-mentioned problems, before correcting the position of the TCP of the working robot R, the deviation ΔK at the site is measured using a three-dimensional measuring device or the like, and offline teaching is performed based on the measured data. It is also conceivable to correct the position of the work robot R on the device. However,
Such an operation not only requires extra time for measurement and correction, but also requires a very expensive three-dimensional measuring device and the like.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and detects an error between a work position of a work robot and a work object easily and with high accuracy without erroneous recognition. It is an object of the present invention to provide a method for detecting an error in offline teaching data that can be performed.

[0011]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a virtual machine created using a CAD system.
Upon operating the actual <br/> working robot according to teaching data D ₀ in the virtual working robot, a method of detecting an error occurring between the workpiece and the working position by the actual working robot, the work object A first step of obtaining first corrected teaching data D _C1 obtained by correcting the teaching data D ₀ by correcting a working position of the actual machine working robot with respect to the teaching data D ₀ ; A second step of obtaining the difference between the first corrected teaching data D _C1 as correction amount data (D _C1 −D ₀ ), and the teaching data D ₀ before correction and the correction amount data (D _C1 −D ₀ ). A third step of finding the difference between the second teaching data D _C2 = {D ₀ − (D _C1 −D ₀ )} and the second teaching data D _C2
The virtual work robot on the CAD system
And displays a fourth a step, determining a correction vector which leads to the working point of the virtual working robot by the teaching data D ₀ before correction from the working point of the virtual working robot according to the second modified teaching data D _C2 will, in the second modified teaching data D _C2
The correction amount and the correction direction of the actual work robot are obtained based on the display image of the virtual work robot and the correction vector.

[0012]

The error detection method of the off-line teaching data the present invention, when operating the actual working robot based on teaching data D ₀ created in a CAD system, the work target working point of the actual working robot (TCP) The first correction teaching data D _C1 is obtained by correcting an error occurring between the work point of the object and the correction data ( _C 1) based on the first correction teaching data D _C1 and the teaching data D ₀ before correction. D _C1 -D ₀₎ Request. Then, the second corrected teaching data D _C2 = {D ₀ − (D _C1 −D ₀ )} is obtained from the teaching data D ₀ before the correction and the correction amount data (D _C1 −D ₀ ). The second corrected teaching data D _C2 is positioned as teaching data before correction with respect to the virtual work object on the CAD system. Therefore, in accordance with the second modified teaching data D _C2, virtual work on the CAD system
Display and display the second correction teaching
Teaching data D before correction from TCP of data D _C2
By determining the correction vector leading to ₀ of TCP, the actual
The correction amount and the correction direction of the mechanical robot can be accurately obtained.

[0013]

FIG. 1 shows an offline teaching device 10 which is a CAD system to which an error detection method for offline teaching data according to the present invention is applied, and a work object based on teaching data created by the offline teaching device 10. To perform a desired operation.

The offline teaching device 10 includes a control unit 14, a CRT 16 for displaying a model of a work robot and a work object, a keyboard 18 and a mouse 20 for giving input / output instructions to the control unit 14.
The teaching of the operation of the work robot is performed, and an error when the teaching data is applied to the work robot at the site is detected.

The robot apparatus 12 includes a work robot R for performing a desired work on a work object on a production line at a site, a robot control unit 22 for controlling the operation of the work robot R based on the teaching data, TC of the work robot R with respect to the work point of the work object
A teaching box 24 for driving and correcting the work robot R when there is a displacement in P is provided.

Here, the offline teaching device 10
As shown in FIG. 2, the control unit 14 controls the whole of the offline teaching device 10.
A storage unit 28 for storing system programs, work data, etc., a drawing control circuit 30 for performing drawing control on the CRT 16, an interface circuit 32 to which the keyboard 18 and the mouse 20 are connected, a work robot R and a work object. A hard disk drive 34 that controls a hard disk that holds model data, a floppy disk drive 36 that controls a floppy disk FD that stores teaching data, a data creation circuit 38 that creates teaching data, and a simulation with the CRT 16 based on the teaching data And a correction vector calculation circuit 42 for calculating a correction amount and a correction direction of the teaching data.

Next, the operation of the offline teaching device 10 and the robot device 12 configured as described above will be described with reference to the flowchart shown in FIG.

First, in the data creation circuit 38 of the offline teaching device 10, the teaching data D _O
Is created (step S10). In this work, for example, the model data of the work robot R and the work object held in the hard disk drive 34 are displayed on the CRT 16 by the drawing control circuit 30, and the work robot R is operated on the CRT 16 using the mouse 20 or the like. It is done by doing.

The created teaching data D _O is simulated on the CRT 16 by the simulation circuit 40 (step S20), and as shown in FIG. 4A, the work point (indicated by ×) of the work object model and the work robot R It is checked whether or not the TCP of the model (shown by ○) matches.

The confirmed teaching data D _O is stored in the floppy disk FD by the floppy disk drive 36, and then stored in the floppy disk FD.
Is downloaded to the robot device 12 at the site via the server (step S30).

[0021] In the robot 12, the working robot R according to the teaching data D _O is driven, the operation check in the field is performed (step S40). in this case,
As shown in FIG. 4B, it is assumed that the work target on the site and the TCP of the work robot R do not match.

Then, the operator at the site operates the work robot R using the teaching box 24, and as shown in FIG.
Correction work is performed to match P. In this case, the robot device 12 creates the first corrected teaching data _DC1 from the state of each axis of the work robot R after the correction (Step S50).

The first modified teaching data D _C1 is
The data is uploaded to the offline teaching device 10 via the floppy disk FD (step S60) and stored in the storage unit 28.

On the other hand, in the offline teaching apparatus 10, the correction vector calculation circuit 42, for each working point corresponding, difference correction amount data (D fixes and previous teaching data D _O and the first corrected teaching data D _{C1 C1}
−D _O ) (step S70).

Next, the teaching data before the correction
D_OAnd the correction amount data (D_C1-D _O) Is the second
Corrected teaching data D_C2= D_O− (D_C1-D_O)When
(Step S80).

[0026] Note that, in step S80, when dealing with the second modified teaching data D _C2 for each axis of the working robot R is simply the second modified teaching data D _C2 by obtaining the difference between the data for each axis Obtainable. On the other hand, when the teaching data D _O before correction and the correction amount data (D _C1 −D _O ) are data of only the TCP of the work robot R, the second correction teaching data D _C2 regarding TCP is obtained. after gives inverse operation (TCP second modified teaching data D _C2 from the second modified teaching data D _C2 of TCP for each axis of the working robot R,
The data for each axis is obtained by solving an equation so that the user can get there.)

The TCP data of the working robot R is extracted from the second corrected teaching data D _C2 and the uncorrected teaching data D _O obtained as described above, and the teaching data D is obtained from the second corrected teaching data D _{C2. A} TCP correction vector V reaching _O is calculated (step S90).

On the other hand, with respect to CRT 16, as shown in FIG. 4D, the working robot R based on teaching data D _O before modification (shown by a solid line), the working robot R (dashed line based on the second corrected teaching data D _C2 Is displayed (step S100).

In this case, if the position of the work object indicated by X is unchanged and the position of the work robot R indicated by the dotted line is regarded as the position based on the teaching data D _O before correction, the work robot R Positional relationship with the object (Fig. 4
The same positional relationship as in B) can be reproduced on the CRT 16. Therefore, the operator can accurately grasp whether the teaching data D _O before correction is set to any state working robot R in the field.

Further, the correction vector V obtained in step S90 corresponds to the T of the work robot R indicated by a dotted line in FIG. 4D.
The correction amount and the correction direction from the CP to the TCP of the work robot R indicated by a solid line are shown. Thus, for example, if only the shape of the workpiece in the same production line is changed, to consider the change data of the shape of the correction vector and workpiece with respect to the teaching data D _O before modification , Without making modifications on site,
Teaching data for a new work object can be efficiently created.

[0031]

As described above, in the method for detecting an error in the offline teaching data of the present invention, the correction amount and the correction direction of the data are calculated using the teaching data after the correction and the teaching data before the correction. The error can be obtained easily and with high accuracy without using an expensive measuring instrument. In addition, since the error is obtained in consideration of the relative positional relationship between the work robot and the work object at the site, for example, by displaying the state of the work robot using this error, the operator Can be accurately grasped. Furthermore, by using the data of the correction amount and the correction direction obtained in this way, it is possible to easily cope with a change in only the shape of the work object, and to efficiently create teaching data.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an offline teaching device and a robot device to which an error detection method for offline teaching data according to the present invention is applied.

FIG. 2 is a circuit configuration block diagram of a control unit in the offline teaching device shown in FIG.

FIG. 3 is a flowchart of a method for detecting an error in offline teaching data according to the present invention.

4A and 4B are explanatory diagrams of an error detection method of off-line teaching data according to the present invention. FIG. 4A is an explanatory diagram of a positional relationship between a work robot on a CRT and a work object, and FIG.
FIG. 4C is an explanatory diagram of the positional relationship between the work robot and the work object at the site, FIG. 4C is an explanatory diagram of the positional relationship between the work robot and the work object after the correction at the site, and FIG. FIG. 4 is an explanatory diagram of a positional relationship between a work robot on a CRT and a work target based on teaching data and teaching data before correction.

FIG. 5 is an explanatory diagram of an error detection method of off-line teaching data according to the related art, and FIG. 5A is an explanatory diagram of a positional relationship between a work robot on a CRT and a work target;
B is an explanatory diagram of the positional relationship between the work robot and the work object at the site, FIG. 5C is an explanatory diagram of the positional relationship between the work robot and the work object after correction at the site, and FIG. FIG. 4 is an explanatory diagram of a positional relationship between a work robot on a CRT and a work target based on teaching data of FIG.

[Explanation of symbols]

Reference Signs List 10 offline teaching device 12 robot device 14 control unit 16 CRT 22 robot control unit 24 teaching box R working robot

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Hidetaka Nose 1-10-1 Shinsayama, Sayama-shi, Saitama Honda Engineering Co., Ltd. (56) References JP-A-4-340605 (JP, A) JP-A Sho 63-206809 (JP, A) JP-A-5-80823 (JP, A) JP-A-5-250018 (JP, A) JP-A-3-55194 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B25J 9/22 G05B 19/42

Claims (1)

(57) [Claims] When 1. A is operated to actual work robot according to teaching data D ₀ of the virtual work <br/> industry robot created using CAD system, the working position and the work target by the actual work robot a method for detecting an error occurring during, to modify the working position of the actual working robot for said work object, a first step of obtaining a first corrected teaching data D _C1 obtained by modifying the teaching data D _0, The difference between the teaching data D ₀ before the correction and the first corrected teaching data D _C1 is calculated as correction amount data (D _C1 −D
₀ ), and a difference between the teaching data D ₀ before correction and the correction amount data (D _C1 −D ₀ ) is calculated as a second correction teaching data D _C2 = ｛D ₀ − (D _C1 −D). ₀ ) According to the third step, which is obtained as｝, and the second corrected teaching data _DC2 , the CA
Displaying the virtual work robot on the D system
In, the temporary by said second correction teaching data D _C2
A fourth step of obtaining a correction vector from the working point of the virtual working robot to the working point of the virtual working robot based on the teaching data D ₀ before the correction by the second corrected teaching data D _C2 .
An error detection method for offline teaching data, wherein a correction amount and a correction direction of the real work robot are obtained based on the display image of the virtual work robot and the correction vector.