Investigation of an Optimal Motion Pattern for a Robotic Fish

摘要

Existing creatures in nature have been adapted to the harsh environment through natural “survival of the fittest” genetic evolutions.A mechanical system cannot have the same functions as bio-organic systems.A robotic fish should be adapted to the given environment.In this paper,an optimal motion pattern for a robotic fish is investigated as an initial stage to more intelligent control of the robotic fish.An equation of describing fish body shape and its motion is expanded to an expanded motion equation.The discrete set of the motion parameters of the expanded equation is set up.The experimental study is performed with the discrete set of the motion parameters by fabricating a robotic fish whose motion has three degrees of freedom at the tail.It is covered with silicon for water proof.It is attached to a 6 axis force sensor in order to measure resultant forces and moments.The energy optimized parameter set is obtained and rearranged with respect to propulsion force.The parameter set is used in the local controller via interpolation.The relation between propulsion force and optimized parameter is analyzed,and the optimized body motion pattern is developed as a function of desired force.