Twelve hour operation of cruising type AUV "R-One Robot" equipped with a closed cycle diesel engine system

Institute of Industrial Science of the University of Tokyo and Mitsui Engineering and Shipbuilding Co. Ltd. are jointly developing an autonomous underwater vehicle called "R-One Robot" which is equipped with an air-independent power (AIP) system of a Closed Cycle Diesel Engine System (CCDE) for long range surveys. The vehicle is 8 m in length and 4 tons in weight, and its depth rating is 400 m. The CCDE produces 5 kW output and its capacity is about 60 kWh which depends on the capacity of tanks for fuel, liquid oxygen and carbon dioxide absorber. The first long range sea trail was conducted in 1996, which included 4 hour operation. This paper presents the outline of long range operation of the R-One Robot conducted in June 1998 in the Pacific Ocean, off the shore of Tanabe, Wakayama Prefecture. In one trial, the robot was launched from the pier of the shipbuilding yard, operated on the surface for about 4 km, descended between 10 m to 50 m and cruised autonomously for 12 hours 37 minutes, for about 70 km. By this sea trial, it is confirmed that the R-One Robot will be a suitable platform for continuous measurement of various chemical and biological properties of water column over a long range taking advantage of a wide payload bay at the fore of the robot.