Research On Swimming Characteristics Of The Device For Oscillating Propulsion Based On Redundant Mirror Symmetrical Parallel Mechanism

After the evolution about hundreds of millions years, fish have already the idealphysiological structure and the highly efficient swimming model. Fish-like propulsiondevices have far superior swimming performance and maneuverability than theconventional underwater vehicle, which has become the study object for many scholars.The oscillating propulsion device is adopted in this paper based on the redundantmirror symmetry parallel mechanism to simulate the real fish. First of all, there is aintroduction and study for the redundant mirror symmetry parallel mechanism, whichmainly includes two aspects: decoupling and the design calculation for the structuralparameters of the redundant mirror symmetry parallel mechanism. The purpose todecouple is to make the device oscillating without coupling the motions on other DOFs.Then, there is a brief introduction of bionics for the caranguiform fish, whosegeometry and kinematics are also described. Based on this, we make the discretizationfor the continuous fish and get its kinematics equation after the discretization. The forceanalysis is carried on the series-parallel mechanisms. Then, based on the amplitudeenvelope of the body lateral deflection, the design method is proposed to calculate therigidity of series-parallel mechanisms on the propulsion device.In the end, the simulation model is established for bionic oscillate propulsionsystem based on SimMechanics, which reflects the hydrodynamics characteristics. Thesimulation analysis shows that when the stiffness designing frequency corresponds tothe driving frequency, the oscillating propulsion device achieves the best swimmingperformance. Meanwhile, the stiffness design calculation method is validated correctly.Moreover, when the oscillating propulsion device is in the steady-swimming condition,the driving frequency has nothing to do with the amplitude, while emerges linear ratiorelation with the swimming speed. In the end, an experimental prototype of theoscillating propulsion device is made by springs, et al. We make two kinds ofexperiment, one is with no water and the other is underwater. And the experimentresults are analyzed...