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Kinematic Robot Calibration Using a Double Ball-Bar

Collin, Sandra (2016) In MSc Theses
Department of Automatic Control
Abstract
Calibration of robots is an essential part of industry today when there is a high accuracy requirement. Several calibration methods have proven to be highly accurate but also expensive and time consuming to use. In this thesis a new calibration method has been developed. The method does not depend on any external measurement systems but instead rely entirely on the robot’s own sensors. The method is based on a closed loop system where a robot is connected to a double ball-bar attached to a rigid point. The ball-bar creates a constraint restraining the robot to a spherical surface. All measured joint positions are fitted to the sphere by altering the geometric representation of the robot. The issues with the method proved to be the process... (More)
Calibration of robots is an essential part of industry today when there is a high accuracy requirement. Several calibration methods have proven to be highly accurate but also expensive and time consuming to use. In this thesis a new calibration method has been developed. The method does not depend on any external measurement systems but instead rely entirely on the robot’s own sensors. The method is based on a closed loop system where a robot is connected to a double ball-bar attached to a rigid point. The ball-bar creates a constraint restraining the robot to a spherical surface. All measured joint positions are fitted to the sphere by altering the geometric representation of the robot. The issues with the method proved to be the process effects as well as dynamic effects influencing the joints and links resulting in incorrectly measured joint positions. Some of these unwanted effects were filtered by applying the clamping method to estimate the joint characteristics. When the new robot geometry was identified, a verification was performed. The verification resulted in an improved positioning of almost 80 % and an improved orientation of 23 % compared to the initial robot geometry. (Less)
Please use this url to cite or link to this publication:
author
Collin, Sandra
supervisor
organization
year
type
H3 - Professional qualifications (4 Years - )
subject
publication/series
MSc Theses
report number
TFRT-6000
ISSN
0280-5316
language
English
id
8870423
date added to LUP
2016-03-30 15:02:29
date last changed
2016-03-30 15:02:29
@misc{8870423,
  abstract     = {Calibration of robots is an essential part of industry today when there is a high accuracy requirement. Several calibration methods have proven to be highly accurate but also expensive and time consuming to use. In this thesis a new calibration method has been developed. The method does not depend on any external measurement systems but instead rely entirely on the robot’s own sensors. The method is based on a closed loop system where a robot is connected to a double ball-bar attached to a rigid point. The ball-bar creates a constraint restraining the robot to a spherical surface. All measured joint positions are fitted to the sphere by altering the geometric representation of the robot. The issues with the method proved to be the process effects as well as dynamic effects influencing the joints and links resulting in incorrectly measured joint positions. Some of these unwanted effects were filtered by applying the clamping method to estimate the joint characteristics. When the new robot geometry was identified, a verification was performed. The verification resulted in an improved positioning of almost 80 % and an improved orientation of 23 % compared to the initial robot geometry.},
  author       = {Collin, Sandra},
  issn         = {0280-5316},
  language     = {eng},
  note         = {Student Paper},
  series       = {MSc Theses},
  title        = {Kinematic Robot Calibration Using a Double Ball-Bar},
  year         = {2016},
}