Study On Undulatory Control Of The Flexible Fin In Undulatory Biomimetic Propulsor

The undulatory biomimetic propulsor is a new-style underwater propulsor which is basedontheswimmingmodeofGymnarchusNiloticus.Itachievesitsforwardorbackwardmovementby undulatory controlof the flexible fin. The undulatory control of the flexible fin is one of thekey techniques for the research of the undulatory biomimetic propulsor, and it is the base ofpropulsion.Due to its high order, nonlinear, and strong coupling, valid mathematical model of theflexiblefinishardtoget.Inthisthesis,therelationofthewaveparametersoftheflexiblefinandthe positions of all rays is proposed. Considering the influence of liquid and the flexiblemembrane, this thesis gives an analysis about the kinematical model of the ray, and gets thedynamicformulationbyamethodofKaneequation.The algorithm oftheundulatorycontroloftheflexiblefinisdesigned.Adoptingthestrategyofdistributedcontrol,thisthesisgives arespectiveresearchonthe servo control oftherayat thenode level and the coordinated control of the flexible fin at the coordinated level. For the ray, anonlinearfeedback controller,whichrealizesthe decouplingofoutput variables,isdesigned. Forthe coordinated control, two non-coupling control strategies and a fuzzy control algorithm withself-adaptabilityaredevisedinthethesis.This thesis presents a design of the tester of the undulatorybiomimetic propulsor and givesan implementation of its control system. Experiments are taken to test the mathematical modeland the algorithms advanced in this thesis. Results indicate that the mathematical model is validandthealgorithmsworkverywell.