Transcript Transformations in V+, VAL3, and TPP Sebastian van Delden USC Upstate

Transformations in V+, VAL3, and
TPP
Sebastian van Delden
USC Upstate
[email protected]
V+
Defining Transformations

The built-in V+ trans function creates
a new transformation:
trans(X, Y, Z, Yaw, Pitch, Roll)
Related V+ Functions



set curpos = HERE
 The here function returns a transformation that represents the
current location of the tool frame (NOTE: set needs to be used to
populate location variables).
decompose curvals[ ] = curpos
 The decompose function can be used to return the 6 position
values.
dx (location)


dy (location)


Returns Y value of location
dz (location)


Returns X value of location
Returns Z value of location
inverse (transformation)

Return the inverse of its parameter
Related V+ Functions

RX(angle)


RY(angle)


Create a pure rotation transformation of angle degrees
around Z.
SHIFT(transformation BY x_shift, y_shift, z_shift)


Create a pure rotation transformation of angle degrees
around Y.
RZ(angle)


Create a pure rotation transformation of angle degrees
around X.
Return a transformation resulting from shifting the
translation values of the transformation parameter.
scale(transformation BY factor)

Returns a scaled transformation
Applying Transformations

Transformations can be multiplied together using a
colon(:) to create a new location.


move trans(10,2,30,90,0,0):rx(30):a
ORDER MATTERS:

move rx(30):trans(100,0,0,0,0,0)



Make a 30 degree rotation around robot world X and then
translate 100 mm down this direction.
I.e. rotation happen around world frame
move trans(100,0,0,0,0,0):rx(30)


Translate 100 mm down the original world X, and then a 30
degree rotation
I.e. rotation happen around tool frame
Defining Tool Transformations/Frames


The tool frame is
located on the tool
flange.
Usually the tool frame
is moved to an
appropriate location in
the tool.


Allows for better tool control
tool trans(X,Y,Z,Yaw,Pitch,Roll)

X,Y,Z,W,P,R are manually determine by user.
Tool Transformations



IMPORTANT: Always assign the tool
transformation before you teach points
AND before you visit those points.
All motion instructions after the tool trans
declaration use that tool frame.
The tool can be redefined at any point in
the program with another tool trans
statement
Tool Transformation Example

What is the tool trans for this tool?
Original
tool frame
on flange
Desired location of
tool frame
Defining Generic Frames

A coordinate system, or frame, can be
created in V+ by teaching 3 locations




An origin, origin.
A location on the X axis, x.
A location on the Y axis, y.
set f = frame(origin, x, y, origin)

The first parameter is where X and Y cross. This
is usually the origin, but you can move this up or
down.
More on Frames



Be careful when moving to a frame.
Consider trying to touch the origin of the
frame in the picture with the tip of tool.
move f


Will crash the arm in the box
move f:trans(0,0,0,0,180,0)

Will align Zs properly
Approaching and Departing Locations

appro(A, 50) or appros(A,50)


Go to a location 50 mm “above” A, where “above”
is along the Z axis associated with A
depart(50) or departs(50)

Move 50 mm away from the current location along
the location’s Z axis.
VAL3
Defining Tool Transformations/Frames

Any number of tool transformations can be
defined as global variables
1. Cursor to “flange”
2. Press “New” Key
- Give the tool transformation a
name, for example, “mytool”
Manually Enter X, Y, Z, W, P, R…
Tool Transformation and Motion

Every motion instruction must include a tool
transformation as a parameter:




movej(somePoint, mytool, motionDescription)
movel(somePoint, mytool, motionDescription)
movec(viaPoint, somePoint, mytool, motionDescription)
No guesswork!
Defining Transformations
trsf
• Transformation Variable
enables to make computation on
Cartesian points
• Ex : Approach on point, Shift in pallet, Compose a new point, ….
• 6 numeric field : x, y, z, rx, ry, rz
• If trsf trShift is defined, two possible ways to populate it with values:
trShift={0,0,-100,0,0,0}
or trShift.x=0 trShift.y=0 trShift.z=-100 trShift.rx=0 ...
Not possible to make motions on trsf
!! Used ONLY for computation on Cartesian !!
Apply a Transformation using APPRO
POINT
←
appro(POINT,TRSF)
APPRO computes a Cartesian point related to a point on which is applied a
transformation
POINT p
POINT pPick TRSF trShiftz NUM nDistance=100 are defined
trShiftz={0,0,-nDistance,0,0,0}
p=appro(pPick,trShiftz)
movej(p,tGrip,mFast)
Or:
movej(appro(pPick,trShiftz),tGrip,mFast)
X
p
-100
Or:
movej(appro(pPick,{0,0,-100,0,0,0}),tGrip,mFast)
X
pPick
Z
tool
Transformation Example 1
movej(appro(pPick,{180,0,-100,0,0,0}),tGrip,mSlow)
movel(appro(pPick,{0,0,-100,0,0,0}),tGrip,mSlow)
movel(pPick,tGrip,mSlow))
2
180
100
X
pPick
Z
3
1
1
2
3
Transformation Example 2
movel(pPick,tGrip,mSlow)
1
movel(appro(pPick,{0,0,0,0,-20,0}),tGrip,mSlow)
2
(Blend =off)
- 20°
2
1
X
X
pPick
pPick
Z
Z
Defining Generic Frames
Importance:
The robot is in production,
The application is working at
full capacity, but ….
Joe is driving the forklift
and ...
!!!! DISASTER !!!!!
… one day for re teaching
locations..
Except if ...
Frame Creation
Local Coordinate system :
• to make points re teaching easier
• used to duplicate locations
• shift of points in a pallet
Frame Teaching
Defined with 3 points to teach :
• Use a precise tool : pointer
• Define this tool as current
• Teach points as far as possible
Y
each other (+ accurate)
X
Axis y
Axis x
Y
World
X
Y
Origin
X
fPallet
POINTS IN A FRAME
Teach points using the frame so that they
are created in the tree branch of the frame.
• During teaching coordinates are
displayed in frame reference
• For the move instruction, it is not
needed to specify the frame:
pA
movej(pA ,tGrip, mFast)
Y
World
X
Y
X
fPallet
Setting a Frame in the Program
nError = setFrame(pOrigin, pX, pY, fRef)
3 points O, X, Y
Error Code :
0 : no error
-1 : ptX too close to ptOrigin
-2 : 3 points are nearly aligned
Frame to compute
(A Pass-by-Reference
Parameter)
Compose can be used to define a new point
in the frame
Compose(point,frame,trsf) : compute a point shifted
by trsf expressed in frame
p=compose(pFirst,fPallet,{160,50,0,0,0,0})
movel(p ,tGrip,mSlow)
Y
World
X
Y
X
fPallet
Using 2 Identical Frames
To use a point with same
coordinates in 2 frames :
• Create a point in each frame
• Teach one of the point
• Copy trsf of point in second one
pRef2.trsf=pRef1.trsf
Y
Y
X
fRef1
World
X
TPP
Defining the Tool Transformation/Frame


The tool coordinate system is defined by
using the frame setup screen or changing the
following system variables.
Ten tool coordinate systems can be defined.
The desired one can be selected.



$MNUTOOL [ 1, i ] (Frame number i = 1 to 10) is
set the value.
$MNUTOOLNUM [ group ] is set the used tool
frame number.
Three ways to set a tool frame.
Navigate to the Tool Offset Menu

Press the MENU key on the teach pendant and then
navigate to SETUP -> FRAMES.
You can define up to 10 tool frames

Select the one you want to define and click DETAIL.
SETIND sets the current tool frame.
Choose which method you want to use to define
the tool frame
Direct (Manual) Method – just type in the X,
Y, Z, W, P, R values
Three Point Method


Defines the only X, Y, Z location of the tool
center point (TCP).
Teach three points that approach the TCP
from different angles



The bigger difference in the angles the better.
Use a stationary point.
There is no “built-in” three point method in
V+…

Exercise: Figure out how to do this in V+/VAL3 
The Three Point Method Idea
Think about the Geometry/Math
TPP walks you through the three point method
The three points to be taught
Six Point Method
Setting the Tool Frame in a Program

A taught location can only be revisited if the
active tool frame is the same one it was
taught with.


The program will generate a run time error if a
different tool frame is active.
The tool frame can be changed in the
program using the UTOOL_NUM = …
command. To find this, press [INST], then:
Setting the Tool Frame in a Program
Set the appropriate
tool frame before the
motion instruction
Taught using tool
frame 2
Taught using tool
frame 1
Defining Generic Transformations/Frames



In TPP, you can define “offsets” which can be
applied to any motion command.
It can be inserted directly in the motion
command.
Example - move to location p[1] with an offset
located in position register 2 (pr[2]):
Step-by-Step Example: Offsets


Recall the previous
program a couple
slides back:
Let’s add an
offset/transformation
so that the point P[3]
is visited with a -50 Z
translation and a 20
degree Yaw rotation
(around X).
Defining the Offset in a Position Register.
2) Press |TYPE|
(F1) and cursor
to Position Reg
1) Press Data
Key
Enter the values: 0,0,-50,20,0,0 and press
done when finished
Modifying the Motion Instruction
Press Edit key to
get back to
program and
cursor over to the
end of the desired
motion instruction.
Then press
CHOICE.
Navigate to Offset, PR[…]
Finish Inserting the Offset

P[3] is now visited with an offset of -50 in tool Z
and a Yaw of 20 degrees.
Offset VERSUS Tool_Offset

Offset


Performs the transformation w.r.t the world
coordinate system
Tool_Offset

There is also a “Tool_Offset” that you can
navigate using the menus which performs the
transformation w.r.t the tool coordinate system.
Defining Generic Frames


Called User Frames in TPP, these frames are defined
and used almost exactly like how tool frames are.
Like with tool frames, navigate to Frames:
If you are still looking at the tool frames, press the
|OTHER| function key and choose User Frame
Manually Enter in the User Frame data or
use one of the built-in methods
Selecting the User Frame
 Just
go back to your program,
and insert the
UFRAME_NUM = …
command similar to how a tool frame
is declared in the program.