Program Correction By Key-Waypoints; Introduction - Universal Robots CB3 Kinematic Calibration Manual

3 Program Correction by Key-waypoints

This tutorial describes how to perform an automatic program correction of key-waypoints, so that a program
can be moved from an uncalibrated robot to another and still work. The technique can also be used to make
programs work after e.g. replacements of joints in a robot.
The functionality is available on Universal Robot controllers with software version 1.7, 1.8, 3.3 and onwards.

3.1 Introduction

NOTE:
Before starting with program correction, backup your original program e.g. by saving it under
a new name. Once a program has been corrected and subsequently saved again, it cannot be
corrected again.
With properly selected and redefined key-waypoints, it is possible to make a model which describes the
difference between the old and the new robot. After the model has been built, the programs are corrected
when loaded. The model can be extended improved at any time by defining more key-waypoints. The model
is specific for each installation file on the robot.
The quality of the model is determined by the number of key-waypoints and the accuracy with which they
are defined. If further correction is desired, the model can be improved by adding more key-waypoints at a
later time.
The accuracy of a corrected waypoint correlates with the quality of the model, and the distance to the
nearest key-waypoint.
Note that currently the program correction functionality does not support the following:
Other types of waypoints besides fixed waypoints
Waypoints contained in the "BeforeStart" program node
A "Move" node which has a selected feature for the motion (different from the "Base" feature)
A "Move" node which sets a selected TCP for the motion.
The unsupported program nodes mentioned above might need to be corrected manually after the auto-
matic correction process has completed.
Figure 3.1: Illustration of the correction
3. Program Correction by Key-waypoints
15