Authors:
Jonas Kräml
and
Carsten Behn
Affiliation:
Technical University of Ilmenau, Germany
Keyword(s):
Bio-inspired Locomotion System, Gait Transition, Adaptive Control, Uncertain System, Gait Generation.
Related
Ontology
Subjects/Areas/Topics:
Industrial Engineering
;
Informatics in Control, Automation and Robotics
;
Mobile Robots and Autonomous Systems
;
Modeling, Simulation and Architectures
;
Robot Design, Development and Control
;
Robotics and Automation
;
Systems Modeling and Simulation
Abstract:
This paper deals with the modeling, analysis and controlled gait transitions of terrestrial artificial locomotion
systems. These systems are inspired by the motion of earthworms and are firstly moving unidirectionally. In
contrast to the analyzed systems in literature, the mechanical model in this paper consists of a chain of 10
discrete mass points. The theory is not restricted to a specified number of mass point, just to a fixed, but
arbitrary number. Recent results from literature present investigations of short worms (n < 4). The movement
of the whole system is achieved by shortening and lengthening of the distances between consecutive mass
points, while they can only move in forward direction. To inhibit the backward movement, a spiky contact
to the ground using ideal spikes – preventing velocities from being negative – are attached to every mass
point realizing the ground contact. The changes of the distances combined with the ground contact results in
a global movement of the
system, called undulatory locomotion. But, to change the distances, viscoelastic
force actuators link neighboring mass points and shall control desired distances in using adaptive control
strategies. Specific gaits are required to guarantee a controlled movement that differ especially in the number of
resting mass points and the load of actuators and spikes. To determine the most advantageous gaits, numerical
investigations are performed and a weighting function offers a decision of best possible gaits. Using these
gaits, a gait transition algorithm, which autonomously changes velocity and number of resting mass points
depending on the spike and actuator force load, is presented and tested in numerical simulations.
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