Universität zu Köln

A neuro-mechanical model for the switching of stepping direction and transitions between walking gaits in the stick insect

Knops, Sascha Alexander (2013) A neuro-mechanical model for the switching of stepping direction and transitions between walking gaits in the stick insect. PhD thesis, Universität zu Köln.

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    In this study, a mathematical model for the locomotion of the stick insect is developed. This model takes physiological conditions into account and it is capable of mimicking biological relevant features. The model is predicated on the crucial role, that sensory feedback plays in the coordination of limbs during walking. Central Pattern Generators (CPGs), which produce the rhythm of locomotion, are affected by sensory influences between the segments. The activities of the CPGs are transferred by the motoneurons to the muscles. Starting with existing neuron models and neuronal network models, a neuro-mechanical model is developed that includes the coupling of segments inside of a leg as well as the coupling of multiple legs. Firstly, mechanical models concerning the motion of the three isolated main joints are derived. These mechanical models are fused with the neuronal one. Thus, they represent neuro-mechanical models for the single joints that are coupled via sensory feedback. By means of the introduction of a switching mechanism the model is able to produce forward, backward and sideward stepping of a middle leg. Through the junction of two stepping middle legs to the body of the modeled stick insect, curve walking sequences with different curvatures can be produced. By extending the model to the front and the hind leg, the structure of intersegmental connection between the legs during the tripod and tetrapod gait can be generated. The change of stepping direction can be brought about by changing one single central command. If the middle leg is stepping backwards, the curvature during turning is smaller than in the case of sideward stepping. Weakly inhibitory intersegmental connections show the most accommodating leg coordination during both the tetrapod and the tripod gait.

    Item Type: Thesis (PhD thesis)
    Knops, Sascha Alexandersknops0@uni-koeln.de
    URN: urn:nbn:de:hbz:38-51200
    Subjects: Natural sciences and mathematics
    Uncontrolled Keywords:
    stick insectEnglish
    Faculty: Mathematisch-Naturwissenschaftliche Fakultät
    Divisions: Mathematisch-Naturwissenschaftliche Fakultät > Zoologisches Institut
    Language: English
    Date: April 2013
    Date Type: Publication
    Date of oral exam: 09 April 2013
    Full Text Status: Public
    Date Deposited: 24 May 2013 11:03:27
    NameAcademic Title
    Gruhn, SilviaDr. rer. nat.
    URI: http://kups.ub.uni-koeln.de/id/eprint/5120

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