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The control and motion planning of bioinspired swimming robots is complicated by the fluid–robot interaction, which is governed by a very high (infinite)-dimensional nonlinear system. Many high dimensional nonlinear systems, often have low-dimensional attractors. From the perspective of swimming robots, such low-dimensional attractors simplify the analysis of the mechanics of swimming and prove to be useful to design controllers. This paper describes such a low-dimensional model for the swimming of a class of robots that are propelled by the motion of an internal reaction wheel. The model of swimming on a low-dimensional attractor is itself motivated by recent work on the dissipative Chaplygin sleigh, a well-known nonholonomic system, that exhibits limit cycle dynamics. We show that the governing equations of the Chaplygin sleigh are a very useful surrogate model for the swimming robot. The Chaplygin sleigh model is used to demonstrate certain maneuvers by the robot through computations. Experiments with such a robot provide evidence of limit cycle dynamics. Computational models based on discrete point vortex–body interaction confirm this behavior. Our work also suggests that there is a close phenomenological and mathematical similarity between the dynamics of swimming robots and those of ground based nonholonomic robots, which could motivate the development of very low-dimensional mathematical models for the motion of other fish-like swimming robots.
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The dynamics of a two link Chaplygin sleigh driven by an internal momentum wheel
A class of aquatic robots have been shown to have a correspondence to terrestrial nonholonomic systems. In particular bodies shaped as a Joukowski foil have been shown to have dynamics similar to a well known nonholonomic system, the Chaplygin sleigh. This inspires several related rigid body nonholonomic systems whose behavior is similar to other aquatic robots with other morphologies. In this paper we investigate the dynamics of one such nonholonomic system, a two-link Chaplygin sleigh that is controlled by an internal momentum wheel. This system is analogous to a similar aquatic robot with a passive tail. We also discuss results related to the accessibility and controllability of the two-link Chaplygin sleigh.
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- Award ID(s):
- 1563315
- PAR ID:
- 10026101
- Date Published:
- Journal Name:
- American Control Conference
- Page Range / eLocation ID:
- 2171 to 2175
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.23919/ACC.2017.7963274
