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.


    Zugriff

    Download


    Exportieren, teilen und zitieren



    Titel :

    Applications of the Virtual Holonomic Constraints Approach : Analysis of Human Motor Patterns and Passive Walking Gaits


    Beteiligte:
    Mettin, Uwe (Autor:in)

    Erscheinungsdatum :

    2008-01-01


    Medientyp :

    Hochschulschrift


    Format :

    Elektronische Ressource


    Sprache :

    Englisch



    Klassifikation :

    DDC:    629



    Virtual Holonomic Constraints: from academic to industrial applications

    Ortiz Morales, Daniel | BASE | 2015

    Freier Zugriff

    Recognition of Human Gaits

    Bissacco, A. / Chiuso, A. / Ma, Y. et al. | British Library Conference Proceedings | 2001


    Gaits and geometry of a walking chair for the disabled

    Zhang, Chang-de / Song, Shin-Min | Elsevier | 1989


    Recognition of human gaits

    Bissacco, A. / Chiuso, A. / Yi Ma, et al. | IEEE | 2001