Navigation & control of an automated SWATH surface vessel for bathymetric mapping

摘要

With the abundant amount of water on the earth, the study of underwater terrain plays an important role in the use and sustainability of marine resources. A wide variety of technical systems are used to collect such bathymetric data, and autonomous vehicles are being explored as a manner in which to make this process more cost-effective. Students in Santa Clara University's Robotic Systems Laboratory are contributing to this effort through the development of an autonomous SWATH boat that can create such maps. As part of this thesis work, the navigation and control system of this SWATH boat has been significantly enhanced. This includes refinement of a path-following controller, development of a trajectory controller that sequences desired paths in a Mow-the-Lawn pattern, and the creation of planning tools to generate trajectories based on high-level descriptions of regions to be mapped. This work included exploration of feed-forward disturbance controllers to improve rejection of wind and current disturbances, and it also included a canard control system to trim vehicle pitch in order to increase mapping speeds. These improvements were experimentally demonstrated in multiple field deployments, and the SWATH vehicle is now capable of providing science-quality bathymetric maps.