liu.seSearch for publications in DiVA
Change search
ReferencesLink to record
Permanent link

Direct link
Visual Servoing Based on Learned Inverse Kinematics
Linköping University, Department of Electrical Engineering.
2007 (English)Independent thesis Basic level (professional degree), 20 credits / 30 HE creditsStudent thesis
Abstract [en]

Initially an analytical closed-form inverse kinematics solution for a 5 DOF robotic arm was developed and implemented. This analytical solution proved not to meet the accuracy required for the shape sorting puzzle setup used in the COSPAL (COgnitiveSystems using Perception-Action Learning) project [2]. The correctness of the analytic model could be confirmed through a simulated ideal robot and the source of the problem was deemed to be nonlinearities introduced by weak servos unable to compensate for the effect of gravity. Instead of developing a new analytical model that took the effect of gravity into account, which would be erroneous when the characteristics of the robotic arm changed, e.g. when picking up a heavy object, a learning approach was selected.

As learning method Locally Weighted Projection Regression (LWPR) [27] is used. It is an incremental supervised learning method and it is considered a state-ofthe-art method for function approximation in high dimensional spaces. LWPR is further combined with visual servoing. This allows for an improvement in accuracy by the use of visual feedback and the problems introduced by the weak servos can be solved. By combining the trained LWPR model with visual servoing, a high level of accuracy is reached, which is sufficient for the shape sorting puzzle setup used in COSPAL.

Place, publisher, year, edition, pages
Institutionen för systemteknik , 2007. , 65 p.
Keyword [en]
Visual servoing, machine learning, lwpr
National Category
Computer Vision and Robotics (Autonomous Systems)
URN: urn:nbn:se:liu:diva-8710ISRN: LITH-ISY-EX--07/3929OAI: diva2:23413
Subject / course
Master of Science Thesis (Magisteruppsats från Affärsjuridiska programmet)
2007-03-12, 10:15
Available from: 2007-04-12 Created: 2007-04-12 Last updated: 2011-08-09

Open Access in DiVA

fulltext(2775 kB)1453 downloads
File information
File name FULLTEXT01.pdfFile size 2775 kBChecksum SHA-1
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Larsson, Fredrik
By organisation
Department of Electrical Engineering
Computer Vision and Robotics (Autonomous Systems)

Search outside of DiVA

GoogleGoogle Scholar
Total: 1453 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 602 hits
ReferencesLink to record
Permanent link

Direct link