Underwater glider ‘SOARER’ for ocean environmental monitoring

Abstract

Underwater glider is one of the most practical and useful autonomous underwater vehicles. Power-driven propulsive machinery is not essential for underwater glider, so that it is applicable to long-term and wide-range operation. Furthermore, this silent and safe underwater vehicle can be maintained with relatively ease and is easy on ocean environment and many forms of life in the sea. An ocean-going underwater glider with independently controllable main wings for the use of ocean-environment monitoring has been developed. This paper deals with tank test and sea trials of the ocean-going underwater glider with independently controllable main wings, named `SOARER'. A simple cylindrical shape with NACA0030-shaped nose and tail cones and tapered main wings with NACA0009 section were adopted for improving the hydrodynamic performance. Main wings, upper rudder, diving rudder (elevator), movable balance weight, and sea-water pump for ballast tank can be controlled by on-board microcomputer system. Three axes acceleration, three axes angular velocity, depth and direction by magnetic compass during cruise can be measured for the use of feedback control. SOARER is navigated by dead reckoning under water, but accurate position can be obtained by using GPS when it is on the surface. These navigation data are transmitted from flight recorder to PC station by wireless LAN system when on the surface. The SOARER glider is equipped with the stand-alone ocean-environment monitoring profiler, `RINKO-Profiler' of JFE Advantech Co., Ltd. Its measuring items are depth, temperature, conductivity, salinity, dissolved oxygen, chlorophyll and turbidity.