6-DoF Navigation Systems for Autonomous Underwater Vehicles

Abstract

Navigation is one of the most critical factors in determining the operational suitability of any unmanned vehicle for its designated environment. In fully autonomous vehicles, due to the lack of a human operator to perform the navigation task, there is a fundamental requirement to incorporate estimation techniques that can provide the desired information necessary for navigation. Such information includes position, attitude, and velocity of the vehicle. In most vehicles, estimating this information is a relatively straight forward process due to the information available from the measurement sensors, particularly position information from Global Positioning System (GPS) sensors. This chapter will focus on the more difficult problem of navigation, particularly positioning, where GPS reception is limited or non-existent. One example where GPS is only partially available is the case of an Autonomous Underwater Vehicle (AUV) where the vehicle is forced to use dead-reckoning in between GPS sightings in order to navigate accurately. Though an underwater environment is used within the context of this example, the techniques examined can be equally applied anywhere where GPS reception is compromised by other electromagnetically opaque mediums, satellite availability or even deliberate denial.