157 research outputs found
Experiments in carangiform robotic fish locomotion
This paper studies a form of robotic fish movement that is analogous to the carangiform style of swimming seen in nature. We propose a simple quasi-steady fluid flow model for predicting the thrust generated by the flapping tail. We then describe an experimental system, consisting of a three-link robot, that has been constructed in order to study carangiform-like swimming. Experimental results obtained with this system suggest that the simplified propulsion model is reasonably accurate. The input parameters that realize optimum thrust are experimentally determined. Finally, we consider some issues in maneuvering
Efficiency of Fish Propulsion
It is shown that the system efficiency of a self-propelled flexible body is
ill-defined unless one considers the concept of quasi-propulsive efficiency,
defined as the ratio of the power needed to tow a body in rigid-straight
condition over the power it needs for self-propulsion, both measured for the
same speed. Through examples we show that the quasi-propulsive efficiency is
the only rational non-dimensional metric of the propulsive fitness of fish and
fish-like mechanisms. Using two-dimensional viscous simulations and the concept
of quasi-propulsive efficiency, we discuss the efficiency two-dimensional
undulating foils. We show that low efficiencies, due to adverse body-propulsor
hydrodynamic interactions, cannot be accounted for by the increase in friction
drag
3D locomotion biomimetic robot fish with haptic feedback
This thesis developed a biomimetic robot fish and built a novel haptic robot fish system based on the kinematic modelling and three-dimentional computational fluid dynamic (CFD) hydrodynamic analysis. The most important contribution is the successful CFD simulation of the robot fish, supporting users in understanding the hydrodynamic properties around it
Trajectory stabilization for a planar carangiform robot fish
Considers the task of trajectory stabilization for a fish-like robot by means of feedback. We use oscillatory control inputs and apply correction signals at the endpoints of each periodic input signal. Such a strategy can be proven to cause the system to converge to a desired trajectory. We present a specific model of a planar carangiform fish, and verify the stabilization results with simulations and with experiment on a planar robotic fish system that is propelled using carangiform-like movements
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