Development of a new underwater positioning system based on sensor network

In those days, the performance of underwater robot is improving because requirements for it are becoming higher and more complex than before. For those work, a highly precise and wide regional underwater positioning system is indispensable. However, the conventional positioning system that has three standard stations, is applicable for the field with no obstacle, because its principal depends on the time based measurement. Therefore, we developed a new underwater positioning system based on sensor network technology that is using a lot of standard stations equipping hydrophone and GPS sensor on the water surface. And decreasing the cost of sensor, we applied a simple method for measurement of distance, which is using sound power level. Therefore, this study has started with confirming the new principal for underwater positioning method. This paper is showing the availability with theoretical analysis and the performance of new method under the noise and reflection of sound in the water, and suggestions for the measures and an error compensation method. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008