umu.sePublications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Applications of the Virtual Holonomic Constraints Approach: Analysis of Human Motor Patterns and Passive Walking Gaits
Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
2008 (English)Licentiate thesis, monograph (Other academic)
Abstract [en]

In the field of robotics there is a great interest in developing strategies and algorithms to reproduce human-like behavior. One can think of human-like machines that may replace humans in hazardous working areas, perform enduring assembly tasks, serve the elderly and handicapped, etc. The main challenges in the development of such robots are, first, to construct sophisticated electro-mechanical humanoids and, second, to plan and control human-like motor patterns.

A promising idea for motion planning and control is to reparameterize any somewhat coordinated motion in terms of virtual holonomic constraints, i.e. trajectories of all degrees of freedom of the mechanical system are described by geometric relations among the generalized coordinates. Imposing such virtual holonomic constraints on the system dynamics allows to generate synchronized motor patterns by feedback control. In fact, there exist consistent geometric relations in ordinary human movements that can be used advantageously. In this thesis the virtual constraints approach is extended to a wider and rigorous use for analyzing, planning and reproducing human-like motions based on mathematical tools previously utilized for very particular control problems.

It is often the case that some desired motions cannot be achieved by the robot due to limitations in available actuation power. This constraint rises the question of how to modify the mechanical design in order to achieve better performance. An underactuated planar two-link robot is used to demonstrate that springs can complement the actuation in parallel to an ordinary motor. Motion planning is carried out for the original robot dynamics while the springs are treated as part of the control action with a torque profile suited to the preplanned trajectory.

Another issue discussed in this thesis is to find stable and unstable (hybrid) limit cycles for passive dynamic walking robots without integrating the full set of differential equations. Such procedure is demonstrated for the compass-gait biped by means of optimization with a reduced number of initial conditions and parameters to search. The properties of virtual constraints and reduced dynamics are exploited to solve this problem.

Place, publisher, year, edition, pages
2008. , 114 p.
Series
Robotics and control lab, ISSN 1654-5419 ; 2
Keyword [en]
Motion Planning, Humanoid Robots, Virtual Holonomic Constraints, Underactuated Mechanical Systems, Mechanical Springs
National Category
Control Engineering
Identifiers
URN: urn:nbn:se:umu:diva-1873ISBN: 978-91-7264-663-6 (print)OAI: oai:DiVA.org:umu-1873DiVA: diva2:142267
Supervisors
Available from: 2008-10-08 Created: 2008-10-08 Last updated: 2016-02-15Bibliographically approved

Open Access in DiVA

fulltext(4244 kB)1198 downloads
File information
File name FULLTEXT01.pdfFile size 4244 kBChecksum SHA-1
ff491201c1da4d1bcea3e0807c3240dcb7f68be46e8fd9bc75c56d771b4571c05c68207b
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Mettin, Uwe
By organisation
Department of Applied Physics and Electronics
Control Engineering

Search outside of DiVA

GoogleGoogle Scholar
Total: 1198 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

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 398 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf