Oceanic Feature Boundary Mapping with an Autonomous Underwater Glider

In this paper, an unknown three-dimensional oceanic feature is analyzed using a single autonomous vehicle. The problem of mapping the three-dimensional underwater feature is posed from a boundary mapping perspective. An autonomous underwater vehicle, specifically a glider, is considered. A dynamic and a kinematic model of the glider is used in order to mimic its movement and to design the control actions to be applied. Differently from previous work, the glider is not requested to follow a predefined trajectory of waypoints, but is considered capable of `intelligently' determining its own trajectory. In particular, the glider defines its direction of movement through a suboptimal sliding mode control method, using only the measurement of the analyzed feature at its current position, in order to achieve the boundary mapping objective. Knowledge of the vehicle position and of the gradient of the analyzed feature is not required. A set of simulations results are provided, based on a realistic dataset relating to a sea temperature front in the Iceland Faroes Front.