The Entity Design And Dynamic Research On The Two-Joint Robot Fish

At the present time, the robot fish always is a focus in the bionic research field. People pay more attention to the research of the thunniform mode robot fish, which has high capabilities of propulsion and high maneuverability. The robot fish could be used in the underwater environment for a long time, with wide-range performance. Moreover, it can be used for the ocean observation, life saving and military areas. It has very high value of application. Depends on the National Natural Science Fund, the entity research and dynamic analyze of the two-joint robot fish are developed in this paper.Take the thunniform mode fish as the research target, the movement of the fish body and the tail fin are analyzed. Three ways of turning and five ways of up and down movement of the robot fish are given. The kinematic model of the thunniform mode fish during steady swimming in one dimension is developed. The drag force of the fish and the way they reduce the drag force are analyzed. Take the two-joint robot fish as the research target, the hydrodynamic force models of the fish body and the tail fin of the two-joint robot fish are developed. The dynamic and efficiency models of the two-joint robot fish in no up and down swimming are developed base on the Lagrange equation.The dynamic simulation of the robot fish is done by the ADAMS software, and the relation between the swing of the fish body and the mass distribution of the robot fish is analyzed. And also the relation between the swing of the fish body and the swing frequency of the tail is analyzed. The impact of the swing of the fish body and on the kinematic parameters of the tail fin is analyzed too. Three ways to restrain the swing of the fish body are presented.Base on the bionic research of the thunniform mode fish and the conclusion of the dynamic simulation of the two-joint robot fish, the robot fish"HRF-Ⅱ"is developed. There are two modules in this new robot fish, the tail module is used to realize forward swimming, and the other module is used to realize the up and down movement. These two modules are separate with each other.The linear swimming, swerve and the up and down movement of the robot fish"HRF-Ⅱ"are carried on in the submarine experiment. The test proves that the swing frequency of the tail fin influence the swimming velocity of the robot fish. Two ways of the turning are tested. The up and down movement and the backward swimming of"HRF-Ⅱ"are tested too.