Study on Stabilization of Undermater Robot with Mechanical Pectoral Fins in Water Currents

本文的研究内容包括：(1)胸鳍运动的实验分析；(2)胸鳍运动的水动力模型；(3)两侧配备胸鳍运动装置的鱼机器人的操纵试验；(4)鱼机器人的导引与控制，特别是在水流中的悬停性能；(5)柔性鳍对其水动力特性影响的数值模拟。研究结论如下：(2)考虑粘性影响的非定常涡格法能较好地表达在施加推力的两种运动之间的相位差范围内，具有羽化运动和超前滞后运动的胸鳍模型所受的非定常作用力。(3)由鱼体模型和一对胸鳍运动装置组成的鱼机器人不仅能在同一位置前后游、转弯，模糊控制的使用使带有一对胸鳍运动装置的鱼机器人能够在预定的航线上游动，并在水流中围绕指定点悬停。(5)与刚性鳍相比，柔性鳍提高了螺旋桨的效率。

This study deals with (I) experimental analysis of pectoral fin motion, (2) the hydrodynamic model for pectoral fin motion, (3) maneuver test of a fish robot equipped with a pair of apparatus of pectoral fin motion on both sides , (4) guidance and control of the fish robot, in particular, the hovering performance in water currents, and (5) numerical simulation of effect of a flexible fin on its hydrodynamic characteristics. The conclusions are as follows ;(1) Observation of pectoral fin motion of Black Bass revealed that the combination of feathering motion and lead-lag motion of a pair of pectoral fins generates the fish motion of advancing, backward swimming, hovering and turning.(2) The unsteady vortex-lattice method including the effect of viscosity can express fairly well the unsteady forces acting on a pectoral fin model having feathering and lead-lag motions in a range of the phase difference between both motions where it exerts thrust force.(3) The fish robot consisting of fish body model and a pair of apparatus of pectoral fin motion can not only swim forward and backward and turn in the same position, but also swim in the lateral direction.(4) The use of fuzzy control enables the fish robot with a pair of the apparatus of the pectoral fin motion swim on a pre-arranged course and hover around an appointed point in a water current.(5) The flexible fin makes it possible to increase the propeller efficiency compared with the rigid fin.