Autonomous underwater vehicle homing/docking via electromagnetic guidance

Central to the successful operation of an autonomous undersea vehicle (AUV) is the capability to return to a dock, such that consistent recovery of the AUV is practical. Vehicle orientation becomes increasingly important in the final stages of the docking, as large changes in orientation near the dock are impractical and often not possible. A number of homing technologies have been proposed and tested, with acoustic homing the most prevalent. If AUV orientation is required as well as bearing and distance to the dock, an acoustic homing system will require high update rates, and extensive signal conditioning. An Electromagnetic Homing (EM) system is one alternative that can provide accurate measurement of the AUV position and orientation to the dock during homing. This system offers inherent advantages in defining the AUV orientation, when compared to high frequency acoustic systems. The design and testing of an EM homing system are given, with particular attention to one can be adapted to a wide class of AUVs. A number of homing, docking, and latching trials were successfully performed with the design. Homing data include dead reckoning computation and acoustic tracking of the homing track, and video documentation of homing into the dock