Basic Research on Monitoring System of Environment in Coastal Waters by Autonomous Underwater Robots

本研究旨在建立1)沿海水域自主水下航行器（auv）的制导与控制系统，2)沿海水域自主水下航行器的配置设计，目的是利用auv开发沿海地区环境的全球监测系统。本文研究了一种具有高姿态控制性能的机械胸鳍自主水下航行器。在该计划的第一年，利用产生扑翼运动、羽毛运动和划船运动的机械鳍系统，从最优控制力生成方面对鳍运动进行了优化。运动学研究表明，鱼类胸鳍运动分为低速时的阻力运动和高速时的升力运动。优化发现基于升力而不是基于升力的游泳方式更适合在均匀流动中产生推进力，而基于阻力而不是基于升力的游泳方式更适合在静水中产生推进力。在该项目的第二年，研制了装有两对机械胸鳍的水下航行器“鸭嘴兽”，以评估其游泳性能和控制性能。我们发现，它不仅具有相当好的推进性能，在升力游泳模式下最大速度可达0.64 m/s，而且在悬停状态下具有转弯、下降和上升、横向游泳等多种机动性。通过前后对机械胸鳍的任务分担，可以在三维水下空间中实现精确的点对点控制，同时实现方位控制、水平面位置控制和深度控制。机械胸鳍基于阻力的游动模式比基于升力的游动模式更适合水下机器人在波浪等扰动下需要快速响应的运动控制。少

This research has been carried out to establish 1) guidance and control system of autonomous underwater vehicles (AUVs) in coastal waters and 2) design of configuration of AUVs in coastal waters for the purpose of development of global monitoring system of environment in coastal area by AUVs. This research deals with an autonomous underwater vehicle equipped with mechanical pectoral fins that has a high performance of attitude control under disturbances like water currents and surface waves in coastal waves.In the first year of this program, the optimization of the fin motion in terms of optimal control force generation was carried out using a mechanical fin system generating flapping motion, feathering motion and rowing motion. Kinematic studies indicate that pectoral fin motion of fish consists of drag-based mode at low speed and lift-based mode at high speed. The optimization found out that the lift-based rather than the drag-based swimming mode is suitable for generation of propuls … More ive force in uniform flow, while the drag-based rather than the lift-based swimming mode is suitable for generation of propulsive force in still water.In the second year of this program, the underwater vehicle equipped with two pairs of mechanical pectoral fins "PLATYPUS" was developed to assess the swimming performance and the control performance. We found that it has not only quite a good propulsive performance, showing the maximum speed of 0.64 m/s with lift-based swimming mode, but also a variety of maneuverability in hovering condition such as turning, descending and ascending, and lateral swimming. The task sharing by fore and aft pairs of mechanical pectoral fins enables a precise Point To Point control in 3-D underwater space that needs simultaneous performance of azimuth control, position control in horizontal plane and depth control. The drag-based swimming mode of the mechanical pectoral fin rather than the lift-based swimming mode is suitable for the motion control of the underwater vehicle that needs a prompt response under disturbances such as waves. Less