To carry out many tasks with some degree of autonomy, for example station-keeping and collision-free navigation, an undersea vehicle needs an accurate knowledge of its position, orientation, and motion relative to nearby objects at all times. Some of this information can be obtained from inertia navigation systems, pressure sensors, and various ranging devices based on sonar and acoustic techniques. Reliable horizontal positioning and motion detection, however, is rather difficult to achieve. For example, Doppler acoustic methods for position location by dead reckoning are sensitive to drift. Other active methods require beacons to be positioned accurately at the work site, and recovered upon completion of the task. This is costly, tedious, and impractical where active sensing is to be avoided. Passive optical sensing can overcome some of the shortcomings of the existing techniques in order to allow accurate short-range positioning in uncontrolled ocean environments (no beacons). We will describe methods for orientation and motion estimation, and give examples of experiments with real images.
ASJC Scopus subject areas
- Control and Systems Engineering
- Computer Science Applications