Development of an Autonomous Underwater Vehicle ""Tri-Dog"" Toward Practical Use in Shallow Water

To develop robots used in an underwater environment, it is necessary to cope with restrictions such as high pressure, low visibility caused by bad transmissivity of light in water, and the fact that electromagnetic wave cannot be used for communications and positioning. Moreover, they operate in oceans and lakes, which involve complicate fluid disturbance and unknown obstacles that are difficult to predict. Therefore, it is important to build full-scale ocean-going vehicles and testbed vehicles, and do experiments in real environments. Sophisticated testbed vehicles are essential facilities for development of highly intelligent systems to be converted to ocean-going vehicles. This paper describes the design of ""Tri-Dog 1"", specifications, tank tests for system identification, and supposed mission. The robot has functions that are higher level than that of practical vehicles, considering experiments in shallow water such as lakes, marshes and shallow sea, and in test tanks. It is possible to apply the developed software system to practical vehicles immediately.