Setting up a 'Pounce Postion' in a robot welding cell

[Willers]

Hi all,

SHORT QUESTION -

How do you create a 'Pounce Position' for a robot welding cell?

(OTC/DAIHEN Almega ax-v6 robot arm)

LONG QUESTION -

With little welding experience and zero robot welding experience, I was dumped with the task of programming a welding cell for a new product after 3 days training. There are some holes in my knowledge to say the least....but anyway.

The robot cell is designed to weld on one side of a jig whilst the other side is loaded with a half completed part. Once one side is welded, the jig rotates round and begins the other half. The robot jig will not rotate and begin welding unless the robot arm itself is in the 'home position'
I remember someone mentioning it being possible to create a 'pounce position' to speed things up slightly.
Could anyone shed any light on where I would start with this?

The teach pendant itself is of the almega-ax series, and the robot arm is the ax-v6

Thanks in advance!

 

[tygerdawg]

No experience whatsoever with OTC-Daihen, but it can't be too much different from all the other robots out there (can it?).

A "pounce position" is an arbitrary point used BEFORE (and usually AFTER also) a series of points defining a path. In your case, a welding path. The Pounce Position is used to safely park the arm+tool in a convenient location ready to move to the beginning point of the path. It should position the arm+tool in a useful configuration (shoulder left/right, elbow up/down, wrist up/down) and also out of the way of any moving elements like rotating fixtures. It doesn't necessarily have to be ONLY ONE point, either. But as many as you need to safely move the arm+tool the way you need to in order to do the motion required. I've always called points for this function "approach points".

I assume you teach/define them with a teach pendant, store to memory, and add motion statements to the program which makes the arm move to, and pause at, these points. When the fixture sends a signal to the robot signalling that it is OK to move, then the robot moves from the pounce position to the start of the path.

In pseudocode, your program structure may be something like this:

_PROGRAM_START
MOVE to SAFEPARK
WAIT for OK_SIGNAL
MOVE to OVER_PATH_START
WAIT for OK_TO_GO_SIGNAL
MOVE to PATH_START
<motion statementst for path>
MOVE to OVER_PATH_END
MOVE to SAFEPARK
_PROGRAM_END

TygerDawg
Blue Technik LLC
Virtuoso Robotics Engineering

http://www.bluetechnik.com

 

[Willers]

Thanks for the reply Tygerdawg,

I think my main problem is with my familiarity with the teach pendant and commands. Ive managed to locate a section in the menu labelled 'possible field to start' in the same section where the home position of the unit is defined. Whilst I think i have saved the position of the robot i want, the jig table will still not accept this as a valid position for movement.
I may have to keep trying to get hold of the guy in Germany who initially trained me.

 

[rosebudd29]

make a pounce path
record a point tag
edit the main program
call the pounce path before the weld path