Content      ..      1      2      3      ..

FANUC R-30iB Plus CONTROLLER, iRVision 2D Camera Application. OPERATOR'S MANUAL - page 2

2. ABOUT VISION SYSTEM

Introduction

Tool offset

Detect the workpiece which gripped by the robot, and offset the robot positions so that the robot works

(for example, the robot places up the workpiece.) in correct.

Camera

Workpicec

Plane on which a workpicec moves

Tool Offset

2.5

CALCULATION OF THE OFFSET DATA

In this subsection, the calculation method of the offset data is explained.

Reference position and actual position

The offset data is calculated from the position of the workpiece of when teaching the robot program and

the position of the current workpiece. The position of the workpiece of when the robot program was

taught is called as the reference position, and the current position of workpiece is called the actual

position. iRVision measures the reference position when the robot program is taught, and stores it

internally. The operation of teaching the reference position to iRVision is called reference position

setting.

Offset data

In the case of the following figure, the position of “+” mark is a found position of a workpiece. If a

robot approaches only to the position of “+” mark, the offset data can be calculated by subtracting the

value of the actual position and the reference position. When the calculation of the offset data is

subtraction, it is easy to understand, however there are also limitations.

10

B-83914EN-2/01

Introduction

2. ABOUT VISION SYSTEM

Workpiece at actual position

2

Workpiece at reference position

Offset frame

Offset calculation by subtraction

In the following figure, the position M is the reference position and the position m is the actual position.

A workpiece is placed on the reference position and the robot traces from the position A to the position B

and C. When the workpiece is placed at the actual position, to trace the -- a, b and c --, each positions

information are required. However, the movement of (a − A), (b − B) and (c − C) differ from the

movement of the found position (m − M). So, it is necessary to calculate the offset data of a, b and c

individually.

a

Motion path of a robot

m

A

c

b

M

B

C

Offset frame

Position Information and movement amount

B-83914EN-2/01

11

2. ABOUT VISION SYSTEM

Introduction

iRVision uses an offset frame, it is unnecessary to calculate the each position individually. In the

following figure, iRVision moves the offset frame to a new position. The position of the workpiece

relative to the offset frame is the same as the position of the workpiece at the reference position by

moving the offset frame, it becomes unnecessary to calculate the offset data for each point individually,

and teaching becomes easy. iRVision outputs the movement of offset frame as the offset data. Since

the offset data is the movement of the user frame, it is not the physically movement of the workpiece.

Moreover, the offset data does not become an intuitive value in many cases. Normally, when the

amount of rotation of the workpiece is the larger or the distance from the origin of the user frame to the

workpiece is the further, the value of the offset data differs from the physically movement of the

workpiece.

a

A

c

b

B

C

Offset data

Moved offset frame

Offset frame

Offset calculation by shifting a frame

12

B-83914EN-2/01

Introduction

2. ABOUT VISION SYSTEM

2.6

PART Z HEIGHT

In the following figure, the two-dimensional camera detects a workpiece. In this case, the found position

2

of the workpiece will be in somewhere on the view line which connects from the workpiece to the

camera.

In order to determine the point on the view line, it is necessary to define the height of a workpiece (Part Z

Height) beforehand. In two-dimensional offset with iRVision, the height of the workpiece measurement

plane on the offset frame is used as the part z height. By setting up the part z height, the XY position of

the workpiece is correctly calculated. (“P1” in the following figure)

The part Z height is the important setting and which influences to the offset accuracy of the robot. So,

please set up the part Z height correctly. When the workpiece is in the center of field of view, the offset

error is too small, but when the workpiece moves to the edges of the field of view, the offset error

becomes large. In this case, it is possible that part Z height is not set properly. In the following figure,

when 0 mm is incorrectly set up in the part z height, the found position of the workpiece is calculated as it

is “P2”, and an offset error occurs in the XY direction.

Camera

Lens

View line

Workpiece measurement plane

Part Z Height

Z

Found position “P1”

Error position “P2”

XY

Offset frame

Detection error in the XY direction XY

Part Z Height

B-83914EN-2/01

13

Introduction

2. ABOUT VISION SYSTEM

Moreover, use a memory card or a USB memory recommended by FANUC. If a memory card or a USB

memory other than those recommended is used, a normal operation is not guaranteed, and a bad influence

may occur on the controller.

2

2.8

CALIBRATION GRID

A calibration grid is a multi-purpose jig that is used for a variety of purposes, such as grid pattern

calibration and grid frame setting.

In iRVision, a calibration of a camera is performed using a calibration grid with a default pattern drawn.

When the camera snaps an image of the grid as shown below, iRVision automatically recognizes the

positional relationship of the calibration grid and the camera, lens distortion, the focal distance, etc.

Y

Origin

X

Example of a frame using a calibration grid

All the black dots of the calibration grid are arrayed in a square lattice. There are four large black dots

near the center that indicate the frame origin and direction as shown in the picture. The ratio of the

diameter of a large black dot to that of other black dots is approximately 10:6.

For the five grid points arranged in the center and at the four corners, there is a white dot with a diameter

of 1 mm placed at the center of the black dot. This white dot is used when setting the frame with

touch-up using the robot's TCP.

Depending on the application, a calibration grid can be used by fixing it to a table or attaching it to the

robot's gripper. In either case, it is necessary to set the arrangement position and direction (mounting

information) of the calibration grid when performing calibration for the camera.

To set up the information for mounting the calibration grid, attach a pointer tool to the robot's gripper and

set it up by physically performing touch-up

(calibration grid setting using touch-up), or set it up

automatically without any contact by using a camera and measuring a grid pattern (grid frame setting).

B-83914EN-2/01

15

3. FEATURES

Introduction

3 FEATURES

The following four application methods are explained below.

•

2D Single-view Vision Process

•

2D Multi-view Vision Process

•

Depalletizing Vision Process

•

3D Tri-View Vision Process

The 2D Single-view Vision Process and 2D Multi-view Vision Process can detect the parallel movement

of the workpiece, (X, Y) direction or the rotational movement (R) direction, and offset the robot position.

The Depalletizing Vision Process can detect not only the parallel movement (X, Y, R) but also the height

(Z) of the workpieces. The 3D Tri-View Vision Process can detect the (X, Y, Z, W, P, R) of the

workpiece.

This chapter explains the outlines of the above four applications, and Chapters 1 to 7 explain the setup

procedures in detail. The 2D Single-view Vision Process is the most standard vision application. The

setup procedure of the 2D Single-view Vision Process can apply to other vision application settings.

For details of each setting item, refer to the iRVision Operator’s Manual (Reference) B-83914EN.

3.1

OVERVIEW OF 2D SINGLE VIEW VISION PROCESS

The 2D Single-view Vision Process can detect the workpiece on a plane with a camera and offset the

robot position depending on the parallel movement (X, Y) direction or the rotational movement (R)

direction of the workpiece. An example of the system layout is shown below. The robot detects the

workpiece on the table and picks up it.

Camera

Workpiece

Table

Example of layout for 2-D Single-View Vision Process

16

B-83914EN-2/01

Introduction

3. FEATURES

3.2

OVERVIEW OF 2D MULTI-VIEW VISION PROCESS

The 2D Multi-view Vision Process measures the multiple points of a workpiece and offset the robot

position in the two-dimensional. This function is used to measure multiple points of a large workpiece

that cannot be contained in the field of view of a single camera.

An example of the system layout is shown below. By using the two cameras, the robot detects the two

3

corners of the large workpiece and picks up the workpiece.

Camera

Workpiece

Pallet

Example of layout for 2-D Multi-View Vision Process

B-83914EN-2/01

17

3. FEATURES

Introduction

3.3

OVERVIEW OF DEPALLETIZING VISION PROCESS

The Depalletizing Vision Process can measure not only the parallel movement of the workpiece but also

the vertical direction of the workpiece. This function can measure the height of the workpieces based on

the size of the workpiece in image. An example of the layout is shown below. The robot detects the

stacked workpieces on the pallet and picks up there in order from the highest workpiece.

Camera

Workpiece

Pallet

Example of layout for Depalletizing Vision Process

18

B-83914EN-2/01

Introduction

3. FEATURES

3.4

OVERVIEW OF 3D TRI-VIEW VISION PROCESS

The 3D Tri-View Vision Process measures the three points of a large workpiece such as a car body, and

offsets the robot in the three-dimensional The offset applies to all of six degrees of freedom for parallel

displacement (X, Y, Z) and rotation (W, P, R) of the workpiece. An example of the layout is shown

below. The robot measures the three points of a large workpiece and offset the robot positions in the

3

three-dimensional.

Target3

Workpiece

Camera1

Target1

Target2

Camera3

Camera2

Example of layout for 3-D Tri-View Vision Process

B-83914EN-2/01

19

Setup

1. 2D SINGLE VIEW VISION PROCESS

1

1

2D SINGLE VIEW VISION PROCESS

The 2D Single-view Vision Process can detect the workpiece on a plane with a camera and offset the

robot position depending on the parallel movement (X, Y) direction or the rotational movement (R)

direction of the workpiece. The 2D Single-view Vision Process can be used in the following four

configurations:

• Fixed frame offset with a fixed camera

• Fixed frame offset with a robot-mounted camera

• Tool offset with a fixed camera

• Tool offset with a robot-mounted camera

This chapter describes the setup procedure for a 2D Single-view Vision Process by using the following

three application examples:

‘Fixed frame offset with a fixed camera’,

‘Fixed frame offset with a

robot-mounted camera’ and ‘Tool offset with a fixed camera’.

In the configuration of ‘Tool offset with a robot-mounted camera’, a robot A holds the camera and robot

B holds the workpiece, and the robot A measures the grip error of the workpiece. The current position

of each robot is needed, so the inter-robot communication function should be set to communicate between

each robot. If a robot A is held a camera but it used as a fixed camera, the setup procedures is same as

‘Tool offset with a fixed camera’.

Fixed frame offset with a fixed camera

An example of a layout for a ‘fixed frame offset with a fixed camera’ is shown below.

Camera

Workpiece

Z

Y

X

Offset frame

Table

Example of a layout for a fixed frame offset with a fixed camera

B-83914EN-2/01

23

1. 2D SINGLE VIEW VISION PROCESS

Setup

Fixed frame offset with a robot-mounted camera

An example of a layout for a ‘fixed frame offset with a robot-mounted camera’ is shown below.

Camera

Workpiece

Z

Y

X

Offset frame

Table

Example of a layout for a fixed frame offset with a robot-mounted camera

Tool offset with a fixed camera

An example of a layout for a ‘tool offset with a fixed camera’ is shown below.

Camera

Z

Y

X

Workpiece

Workpiece deviation plane

Offset frame

Example of a layout for a tool offset with a fixed camera

24

B-83914EN-2/01

Setup

1. 2D SINGLE VIEW VISION PROCESS

1.1

FEATURES AND NOTES

1

Features

•

2D single-view vision process is the most standard application of a 2-D view vision process.

•

It supports the fixed frame offset and the tool offset.

•

Both a fixed camera and a robot-mounted camera can be used.

•

When a robot-mounted camera is used, even if when the robot moves the camera in the X and Y

directions on the offset frame, the position of a workpiece can be measured. This is because,

iRVision calculates the positions of the workpiece based on the current position of the robot.

Notes

• The offset is applied to the XY and R directions. Therefore, each measurement plane should be

parallel to the XY plane of the offset frame and should not be tilted.

• Ideally, the optical axis of the camera should be vertical to the XY plane of the offset frame. When

the position of the camera is tilted against the measurement points of the workpiece, the shape of the

workpiece in the image may change depending on the location of the workpiece, so the detection

may become difficult.

1.2

SETUP FOR FIXED FRAME OFFSET WITH FIXED

CAMERA

The setup procedures for the fixed frame offset with the fixed camera is shown below:

1.

Camera Data Creation and Teaching

2.

Offset frame setting

3.

Vision process creation and teaching

4.

Robot program creation and teaching

5.

Robot compensation operation check

When create the vision system newly, perform all of the above procedures. When the position of the

installed camera is changed or the cameras are exchanged, redo the camera calibration in ‘1 Camera Data

Creation and Teaching’. When you need to add a new kind of workpiece, if a camera calibration has

been already done, the re-calibration of the camera is not needed. Perform ‘3 Vision process creation

and teaching’ and ‘4 Robot program creation and teaching’.

B-83914EN-2/01

25

1. 2D SINGLE VIEW VISION PROCESS

Setup

1.2.1

Camera Data Creation and Teaching

Create a camera data and perform basic settings and calibration of the camera.

The Grid Pattern Calibration and the Robot-generated Grid Calibration can be used to calibrate a fixed

camera.

• For details of the grid pattern calibration, refer to Know-how Edition Section 2.1, "GRID PATTERN

CALIBRATION WITH A FIXED CAMERA".

• For details of robot-generated grid calibration, refer to Know-how Edition Section

2.3,

"ROBOT-GENERATED GRID CALIBRATION".

1.2.2

Offset Frame Setting

The offset frame is used for the calculation of the offset data in the 2D Single-view Vision Process. The

position of a found workpiece is outputted as the position on the offset frame. In the fixed frame offset,

the offset frame is set as a user frame.

Set an offset frame so that the XY plane of the offset frame is parallel with the table plane where the

workpiece is placed. When the offset frame is not parallel with the plane where the workpiece is placed,

the accuracy of offset may become low.

Camera

Workpiece

Z

Y

X

Offset Frame

Table

Offset Frame setting

In the following figure, the plane where the workpiece are placed is tilt against the robot’s world frame.

Set the offset frame so that the plane where the workpiece are placed is parallel with the XY plane of the

offset frame.

26

B-83914EN-2/01

Setup

1. 2D SINGLE VIEW VISION PROCESS

Camera

1

Optical axis of a camera

Z

X

Y

Offset Frame

Offset Frame setting (When an inclined work table is installed)

‘Touch-up with the pointer tool’ and ‘Automatic Grid Frame Setting Function’ can be used to set the

offset frame.

Touch-up

When set the user frame by touch-up method, a pointer tool with TCP is needed. In general, attach the

pointer tool to the robot hand and set the TCP accurately at the tip of the pointer tool. If the accuracy of

TCP setting is low, the accuracy of the offset is also degraded. Set a TCP in an arbitrary tool frame.

When you reuse the pointer tool later, install the pointer tool in where the same location as when the TCP

setting had performed. If the reproducibility of pointer installation is not assured, a TCP setting needs

again. For details, refer to Know-how Edition Subsection 1.1.1, "User Frame Setting".

Grid Frame Setting Function

The Grid Frame Setting Function sets the user frame on the calibration grid frame by using a camera.

Install a calibration grid so that the XY plane of the calibration grid is parallel with the plane where the

workpiece is placed, and perform the Grid Frame Setting Function. For details, refer to Know-how

Edition Section

1.2, "FRAME SETTING WITH THE GRID FRAME SETTING FUNCTION".

When a fixed camera is used, prepare another temporary camera to perform the Grid Frame Setting

Function. The Grid Frame Setting Function can be only used with the 6-axis robot. This function

cannot be used with the 4-axis robot and the 5-axis robot. When the 4-axis robot or the 5-axis robot is

used, use the touch-up method.

B-83914EN-2/01

27

1. 2D SINGLE VIEW VISION PROCESS

Setup

1.2.3

Vision Process Creation and Teaching

Create a vision process and teach it. In addition, teach the locator tools and set the reference position.

1.2.3.1 Vision process creation

1

Create a vision process for [2-D Single-View Vision Process].

For details of the vision process creation, refer to Setup Edition Subsection 1.3.1.1, "Create" in the

"R-30iB Plus Controller iRVision Operator's MANUAL(Reference) B-83914EN".

2

On the vision data list screen, when a created vision process is selected and clicked [Edit], the vision

data edit screen will appear.

3

4

5

3

From the [Camera] drop-down box, select the camera data to be used.

Select the camera data specified in Setup Edition Subsection 1.2.1, "Camera Data Creation and

Teaching".

4

From the [Offset Mode] drop-down box, select [Fixed Frame Offset].

5

From the [Offset Frame] drop-down box, select the user frame to set.

Select the frame number specified in Setup Edition Subsection 1.2.2, "Offset Frame Setting".

28

B-83914EN-2/01

Setup

1. 2D SINGLE VIEW VISION PROCESS

1.2.3.2 Command tool teaching

1

1

Place a workpiece in the field of view of the camera.

2

3

2

Set up the snap tool.

The snap tool is a tool that snaps images that are used to teach and find models. Set the snap

conditions such as the snap window and the exposure time. For details, refer to Setup Edition

Section

4.1, "SNAP TOOL" in the "R-30iB Plus CONTROLLER iRVision OPERATOR’S

MANUAL (Reference) B-83914EN".

3

Select a locator tool from the tree view and teach the model to use for detection.

By default, the GPM Locator Tool is set as the locator tool. For details of the GPM Locator Tool

and other command tools, refer to Setup Edition Section 4, "COMMAND TOOLS" in "R-30iB Plus

CONTROLLER iRVision OPERATOR’S MANUAL (Reference) B-83914EN".

B-83914EN-2/01

29

1. 2D SINGLE VIEW VISION PROCESS

Setup

1.2.3.3 Reference position setting

1

Select [2-D Single-View Vision Process] from the tree view.

1

2

4

5

2

In the text box for [Part Z Height], enter the height of the detected part of the workpiece.

When the XY plane of the offset frame is apart from the detected part of the workpiece, enter the

distance.

Enter an appropriate value as shown in the figure below.

Camera

Part Z Height

Z

Workpiece

X

Table

Offset Frame

Offset Frame and Part Z Height

30

B-83914EN-2/01

1. 2D SINGLE VIEW VISION PROCESS

Setup

1.2.5

Robot Compensation Operation Check

Check that a placed workpiece on the table can be detected and handled accuracy.

• Place the workpiece on the reference position, find it and check the handling accuracy. If the

accuracy of the offset is low, set the reference position again.

• Move the workpiece without rotation, find it and check the handling accuracy. If the accuracy of

the offset is good on the reference position but it lows on the edge of the field of view, it is possible

that

[Part Z Height] is not set properly. Check the

[Part Z Height], refer to Setup Edition

Subsection 1.2.3.3, "Reference position setting".

• Rotate the workpiece, find it and check the handling accuracy. If the accuracy of the offset is good

on the non-rotated workpiece but it lows on rotated workpiece, it is possible that the offset frame or

the calibration grid frame is not set properly. When set the frames using the touch-up method with

a pointer tool, check the TCP setting is precise. Moreover, check the offset frame and calibration

grid frame are set precisely. If there is necessary, retry the camera calibration. If it is difficult to

retry the camera calibration, the "ADJ_OFS" may improve the situation without the re-set up the

offset frame and the calibration grid location. ADJ_OFS is included in VISION SUPPORT

TOOLS. Refer to Setup Edition Subsection

8.1.6, "ADJ_OFS" in the "R-30iB Plus

CONTROLLER iRVision OPERATOR’S MANUAL (Reference) B-83914EN" for details.

• Start with lower override of the robot to check that the logic of the program is correct. Next,

increase the override to check that the robot can operate continuously.

1.3

SETUP FOR FIXED FRAME OFFSET WITH ROBOT

MOUNTED CAMERA

The setup procedures for the fixed frame offset with the robot mounted camera is shown below:

1.

Camera Data Creation and Teaching

2.

Offset frame setting

3.

Vision process creation and teaching

4.

Robot program creation and teaching

5.

Robot compensation operation check

When create the vision system newly, perform all of the above procedures. When the position of the

camera on the robot mechanical interface (the robot face plane) is changed or the cameras are exchanged,

redo the camera calibration in ‘1 Camera Data Creation and Teaching’. When you need to add a new

kind of workpiece, if a camera calibration has been already done, the re-calibration of the camera is not

needed. Perform ‘3 Vision process creation and teaching’ and ‘4 Robot program creation and teaching’.

32

B-83914EN-2/01

Setup

1. 2D SINGLE VIEW VISION PROCESS

1.3.1

Camera Data Creation and Teaching

1

Create a camera data and perform basic settings and calibration for the camera.

When a robot-mounted camera is used, perform the ‘Grid Pattern Calibration’. When a robot-mounted

camera is used, the ‘Robot-Generated Grid Calibration’ cannot be used. For details of the grid frame

calibration, refer to Know how Edition Section 2.2, "GRID PATTERN CALIBRATION WITH A

ROBOT-MOUNTED CAMERA".

1.3.2

Offset Frame Setting

The offset frame is used for the calculation of the offset data in the 2D Single-view Vision Process. The

position of a found workpiece is outputted as the position on the offset frame. In the fixed frame offset,

the offset frame is set as a user frame.

Set an offset frame so that the XY plane of the offset frame is parallel with the table plane where the

workpiece is placed. When the offset frame is not parallel with the plane where the workpiece is placed,

the accuracy of offset may become low.

Robot-mounted camera

Workpiece

Z

Y

X

Offset Frame

Table

Offset Frame setting

There are two methods to teach the offset frame, one is touch-up with the pointer tool, and another is the

Automatic Grid Frame Setting Function.

Touch-up

When set the user frame by touch-up method, a pointer tool with TCP is needed. In general, attach the

pointer tool to the robot hand and set the TCP accurately at the tip of the pointer tool. If the accuracy of

TCP setting is low, the accuracy of the offset is also degraded. Set a TCP in an arbitrary tool frame.

When you reuse the pointer tool later, install the pointer tool in where the same location as when the TCP

setting had performed. If the reproducibility of pointer installation is not assured, a TCP setting needs

again. For details, refer to Know-how Edition Subsection 1.1.1, "User Frame Setting".

B-83914EN-2/01

33

1. 2D SINGLE VIEW VISION PROCESS

Setup

Grid Frame Setting Function

The Grid Frame Setting Function sets the user frame on the calibration grid frame by using a camera.

Install a calibration grid so that the XY plane of the calibration grid is parallel with the plane where the

workpiece is placed, and perform the Grid Frame Setting Function. For details, refer to Know-how

Edition Section 1.2, "FRAME SETTING WITH THE GRID FRAME SETTING FUNCTION". When a

robot-mounted camera is used, the camera can be used for the Grid Frame Setting Function. When there

is not sufficient space to perform the Grid Frame Setting Function with the camera, prepare another

temporary robot-mounted camera and perform the Grid Frame Setting Function. The Grid Frame

Setting Function can be only used with the 6-axis robot. This function cannot be used with the 4-axis

robot and the 5-axis robot. When the 4-axis robot or the 5-axis robot is used, use the touch-up method.

1.3.3

Vision Process Creation and Teaching

Create a vision process and teach it. In addition, teach the locator tools and set the reference position.

1.3.3.1 Vision process creation

1

Create a vision process for [2-D Single-View Vision Process].

For details of the vision process creation, refer to Setup Edition Subsection 1.3.1.1, "Create" in the

"R-30iB Plus CONTROLLER iRVision OPERATOR’S MANUAL (Reference) B-83914EN".

2

On the vision data list screen, when the created vision process is selected and clicked [Edit], the

vision data edit screen will appear.

3

4

5

3

From the [Camera] drop-down box, select the camera data to be used.

Select the camera data specified in Setup Edition Subsection 1.3.1, "Camera Data Creation and

Teaching".

4

From the [Offset Mode] drop-down box, select [Fixed Frame Offset].

5

From the [Offset Frame] drop-down box, select the user frame to set.

Select the frame number specified in Setup Edition Subsection 1.3.2, "Offset Frame Setting".

34

B-83914EN-2/01

Setup

1. 2D SINGLE VIEW VISION PROCESS

1.3.3.2 Command tool teaching

1

1

Place a workpiece in the field of view of the camera.

2

Move the robot to the measurement position where the workpiece can be snapped.

Record this robot position as the first measurement position. Refer to the sample program in Setup

Edition Subsection 1.3.4, "Robot Program Creation and Teaching". P[1] in line 4 is the first

measurement position. Record the current robot position to P[1].

3

4

3

Set up the snap tool.

The snap tool is a tool that snaps images that are used to teach and find models. Set the snap

conditions such as the snap window and the exposure time. For details, refer to Setup Edition

Section

4.1, "SNAP TOOL" in the "R-30iB Plus CONTROLLER iRVision OPERATOR’S

MANUAL (Reference) B-83914EN".

4

Select a locator tool from the tree view and teach the model to use for detection.

By default, the GPM Locator Tool is set as the locator tool. For details of the GPM Locator Tool

and other command tools, refer to Setup Edition Section 4, "COMMAND TOOLS" in the "R-30iB

Plus CONTROLLER iRVision OPERATOR’S MANUAL (Reference) B-83914EN".

B-83914EN-2/01

35

1. 2D SINGLE VIEW VISION PROCESS

Setup

1.3.3.3 Reference position setting

1

Select [2-D Single-View Vision Process] from the tree view.

1

2

4

5

2

In the text box for [Part Z Height], enter the height of the detected part of the workpiece.

When the XY plane of the offset frame is apart from the detected part of the workpiece, enter the

distance.

3

Click [SNAP] and snap the image, and click [FIND] to detect the workpiece.

CAUTION

Do not move the workpiece until the reference position setting is complete.

Part Z Height

Z

Workpi

X

Offset Frame

Table

Offset Frame and Part Z Height

36

B-83914EN-2/01

1. 2D SINGLE VIEW VISION PROCESS

Setup

1.3.5

Robot Compensation Operation Check

Check that a placed workpiece on the table can be detected and handled accuracy.

• Place the workpiece on the reference position, find it and check the handling accuracy. If the

accuracy of the offset is low, set the reference position again.

• Move the workpiece without rotation, find it and check the handling accuracy. If the offset

accuracy is good on the reference position but it lows on the edge of the field of view, it is possible

that

‘Part Z Height’ is not set properly. Check the

[Part Z Height], refer to Setup Edition

Subsection 1.3.3.3, "Reference position setting".

• Rotate the workpiece, find it and check the handling accuracy. If the accuracy of the offset is good

on the non-rotated workpiece but it lows on rotated workpiece, it is possible that the offset frame or

the calibration grid frame is not set properly. When set the frames using the touch-up method with

a pointer tool, check the TCP setting is precise. Moreover, check the offset frame and calibration

grid frame are set precisely. If there is necessary, retry the camera calibration. If it is difficult to

retry the camera calibration, the ADJ_OFS may improve the situation without the re-set up the offset

frame and the calibration grid frame. ADJ_OFS is included in VISION SUPPORT TOOLS.

Refer to Setup Edition Subsection 8.1.6, "ADJ_OFS" in the "R-30iB Plus CONTROLLER iRVision

OPERATOR’S MANUAL (Reference) B-83914EN" for details.

• Depending on robot motion, a camera may vibrate at snap position. Execute "WAIT" instruction to

remove the possible vibration of a workpiece before the detection.

• Start with lower override of the robot to check that the logic of the program is correct. Next,

increase the override to check that the robot can operate continuously.

1.4

SETUP FOR TOOL OFFSET WITH FIXED CAMERA

Snap a gripped workpiece by the robot with misaligned, and measure the amount of the misaligned. The

robot places the workpiece accurately to the specified position.

An example layout of "tool offset with fixed camera" is shown below:

Fixed camera

Z

Y

X

Workpiece

Workpiece deviation plane

Offset frame

Example of a layout for a tool offset with a fixed camera

38

B-83914EN-2/01

Setup

1. 2D SINGLE VIEW VISION PROCESS

The setup procedures for the tool offset with thefixed camera is shown below:

1

1.

Camera Data Creation and Teaching

2.

Offset frame setting

3.

Vision process creation and teaching

4.

Robot program creation and teaching

5.

Robot compensation operation check

When create the vision system newly, perform all of the above procedures. When the position of the

camera is changed or the cameras are exchanged, redo the camera calibration in ‘1 Camera Data Creation

and Teaching’. When you need to add a new kind of workpiece, if a camera calibration has been already

done, the re-calibration of the camera is not needed. Perform ‘3 Vision process creation and teaching’

and ‘4 Robot program creation and teaching’.

1.4.1

Camera Data Creation and Teaching

Create a camera data and perform basic settings and calibration for the camera.

The Grid Pattern Calibration and the Robot-generated Grid Calibration can be used to calibrate a fixed

camera.

Grid Pattern Calibration

When the Grid Pattern Calibration is used for the calibration of tool offset, it is recommended to set the

calibration grid on a dummy workpiece. In the following figures, the calibration grid is installed on the

same position as the measurement position of workpiece. Prepare a dummy workpiece so that it can be

gripped instead of an actual workpiece, and install the calibration grid on the dummy workpiece. By

using this method, setup of the offset frame can be simplified.

B-83914EN-2/01

39

1. 2D SINGLE VIEW VISION PROCESS

Setup

Dummy workpiece

Workpiece

Calibration grid

Workpiece deviation plane

How to attach a calibration grid

When install a calibration grid so that the XY plane of the calibration grid is parallel with the plane where

a workpiece moves, a setup of the offset frame becomes easy. For details of the grid frame calibration,

refer to Know-how Edition Section

2.1, "GRID PATTERN CALIBRATION WITH A FIXED

CAMERA".

Robot-generated Grid Calibration

When the robot-generated grid calibration is used for the calibration of tool offset, it is recommended to

attach a target mark to a dummy workpiece for calibration. Prepare a dummy workpiece so that it can

be gripped instead of an actual workpiece, and install the target mark on the dummy workpiece. By

using this method, setup of the offset frame can be simplified.

Set a target mark so that the XY plane

of the target mark is parallel with the plane on where a workpiece moves.

For details of the Robot-generated Grid Calibration, refer to Know-how Edition Section

2.3,

"ROBOT-GENERATED GRID CALIBRATION".

40

B-83914EN-2/01

Setup

1. 2D SINGLE VIEW VISION PROCESS

1.4.2

Offset Frame Setting

1

The offset frame is used for the calculation of the offset data in the 2D Single-view Vision Process. A

found position is outputted as a position on the offset frame. In the fixed frame offset, the offset frame

is set as a user frame, but in the tool offset, it is set as a tool frame.

Set a tool frame so that the XY plane of the tool frame is parallel with the workpiece deviation plane.

When the Grid Pattern Calibration is used, if the XY plane of the tool frame that is set in Know-how

Edition Subsection 2.1.4, "Calibration" is parallel with the workpiece deviation plane, the tool frame can

be used as the offset frame.

Z

Y

Offset frame

( = Tool frame)

X

Offset frame setting

When the Robot-generated Grid Calibration is used, if the XY plane of the tool frame (UTool for work

space) that is set in Know-how Edition Subsection 2.3.8, "Measuring target position" is parallel with the

deviation plane of the workipece, the tool frame can be used as the offset frame. In this case, it is

recommended to copy the values of the UTool for work space to another tool frame number and specify it

as the offset frame number. For example, when the UTool for work space number is 9, copy the value

of the UTool for work space to arbitrary another tool frame numbers (for example, the tool frame number

is 1), and select the tool frame number as the offset frame.

1.4.3

Vision Process Creation and Teaching

Create a vision process and teach it. In addition, teach the locator tools and set the reference position.

1.4.3.1 Vision process creation

1

Create a vision process for [2-D Single-View Vision Process].

For details of the vision process creation, refer to Setup Edition Subsection 1.3.1.1, "Create" in the

"R-30iB Plus CONTROLLER iRVision OPERATOR’S MANUAL (Reference) B-83914EN".

2

On the vision data list screen, when the created vision process is selected and clicked [Edit], the

vision data edit screen will appear.

B-83914EN-2/01

41

1. 2D SINGLE VIEW VISION PROCESS

Setup

3

4

5

3

From the [Camera] drop-down box, select the camera data to be used.

Select the camera data specified in Setup Edition Subsection 1.4.1, "Camera Data Creation and

Teaching".

4

From the [Offset Mode] drop-down box, select [Tool Offset].

5

From the [Offset Frame] drop-down box, select the tool frame to set.

Select the frame number specified in Setup Edition Subsection 1.4.2, "Offset Frame Setting".

1.4.3.2 Command tool teaching

1

Place a workpiece in the field of view of the camera.

2

Move the robot to the measurement position where the workpiece can be snapped.

3

4

3

Set up the snap tool.

The snap tool is a tool that snaps images that are used to teach and find models. Set the snap

conditions such as the snap window and the exposure time. For details, refer to Setup Edition

Section

4.1, "SNAP TOOL" in the "R-30iB Plus CONTROLLER iRVision OPERATOR’S

MANUAL (Reference) B-83914EN".

42

B-83914EN-2/01

Content      ..      1      2      3      ..