ABB 0503060880, Applications Manual, Page: 17 / 90

2.2 Theory of operation
Example of operation
When the robot is programmed to revolve around the TCP all robot axes will move
accordingly to keep the TCP stationary (see the following figures). If the torch is
damaged and the program is run again, the robot repeats the same movements,
but the TCP will no longer follow the same path due to the misalignment. You now
have two choices:
1 Physically move the torch back into alignment (a task that could be difficult
if not impossible) or
2 Adjust for the misalignment automatically by redefining the TCP to the new
torch position using the BullsEye. After the BullsEye system updates the
current TCP definition, the torch will rotate around the TCP as before because
the robot arm has adjusted its path to compensate for the torch misalignment.
Once a point has been programmed, the robot remembers the tool center point
location, not what the angles of the robot joints are. When the robot replays the
programmed path, it calculates what the joint angles should be to get the TCP back
to where it was when the path was programmed initially. As long as the robot
controller is kept informed about where the tool center point is, it will always keep
the paths properly adjusted.
Robot arm and torch movement with correct TCP
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Application manual - BullsEye 17
3HAC050989-001 Revision: C
© Copyright 2004-2018 ABB. All rights reserved.
2 Introduction to BullsEye®
2.2 Theory of operation