Compact underwater vehicle with accurate positioning system

Currently a platform to investigate the underwater environment is required. In this paper, we propose an autonomous underwater vehicle (AUV) with an accurate positioning system. The positioning system is developed to be accurate enough to utilize the superior navigation ability of our AUV feature. The navigation ability is acquired by the variable vector propeller mechanism. The accurate positioning became possible by introducing two acoustic signals with different frequencies. The range data were obtained satisfactorily with maximum error less than 0.01m. Using the positioning system, the navigation trajectory of the AUV could be measured.