| Summary: | Two types of biomimetic robotic fishes are studied for two different tests. A two
Degree of Freedom (DOF) body and/or caudal fin (BCF) robotic fish and a multi-
DOF slender robotic fish is used for the study of the adaptation of robotic fish to
unsteady flow and to test for robotic fish swimming efficiency respectively. The BCF
robotic fish uses a closed-loop motion control system with velocity and position
feedback, to control the amplitude and frequency of its tail. With different velocity
settings, the BCF fish are proved to hold its desired position. The multi-DOF robotic
fish uses Lighthill’s small-amplitude elongated body theory for improving its
swimming efficiency. The testing parameters for swimming efficiency are its
swimming velocity and power consumption. Power consumption are measured in
real-time through using the strain data, acquired at cranks of the robotic fish. In the
experiments, BCF robotic fish succeed in swimming against transient flow and the
multi-DOF robotic fish recorded had the best efficiency of swimming and fastest
swimming velocity when swimming with the fins movement of 1.0 Hz and 2.0 Hz
frequency and amplitude of 0° and 20° to the first fin and 30° and 40° to the last fin
respectively. Future work like online motion planning and future experiment on the
robotic fishes are still in discussion.
National Instrument (NI) and LabVIEW are widely used in motion control and data
acquisition in recent years. LabVIEW is used on BCF robotic fish and multi-DOF
slender robotic fish for real-time control and data acquisition. Its functionality and
purpose are further explained. Problems and solutions are revealed and the choice of
using the NI instruments and cards are also been justified.
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