Autonomous underwater vehicles (AUV) are quite important for the human being to develop the marine resources. The screw propeller has disadvantages on mechanical efficiency, noise and maneuverability as key component of AUV. Through the evolution of about billion years, fish holds super swimming abilities. The AUV technology can be improved greatly provided fish propulsion modes are applied to thrusters rationally. Towards some deficiencies at bionic design, driving framework and up-down device of the existing fish-like underwater robots, the mini-joint bionic robot fish with high maneuverability, high stability, up-down locomotion and flexible appearance have been developed successfully, based on two propulsion mode of body/caudal fin (BCF) motion and median/paired fin motion.A kinematic model of the cruising of large-amplitude's BCF is established based on fish body's centerline, and the family of curves are obtained through simulations and experiments to reproduce fish motion. After analysis and calculation of forces by neighboring fluids at the lengthwise, lateral and up-down directions, the dynamical model and propulsion efficiency of the robot fish is deduced. On the grounds of simulations and prototype tests on various swimming performance indicators, the influences of various parameters controlling motions have been discussed. By analysis of high-speed photography of the crucian's pectoral fin oscillation, a simplified physical model and kinematical equation of MPF are brought forward. Considering non-steady effect of attack's time-variation, the dynamical model is established and modified. Both regular pattern and composition, of swimming velocity, propulsive force and efficiency, are analyzed in accordance with multi-gait simulations. Thus the inherent relations between kinematic parameters and swimming performances can be found out.The basic theory of fast-start kinematics is studied, and motion equations of S-start and C-start are established. Subsequently, law of motion of body centerline are... |