In January, the Autonomous Systems and Controls Laboratory (ASCL), in collaboration with the Naval Postgraduate School, field tested its sensing and autonomy system for unmanned surface vehicles (USVs) on Mississippi's Pearl River. "We successfully demonstrated long-range missions by traveling up and down the Pearl in an area between Stennis Space Center and the Gulf of Mexico," says Associate Professor Dan Stilwell, director of the laboratory.
The effort focuses on very large tropical riverine systems and the Pearl River provided a good test field. "The USV senses objects above the water with a laser line-scanner and below the water with a forward-looking sonar," explains Stilwell. The team has also developed new methods for representing maps that allow them to plan and modify missions in real-time based on information from the sensors. "Surprisingly, even existing maps of the Pearl River have significant inaccuracies, so it was necessary for the USV to make sense of the environment as it went."
The ASCL team is developing a sensing and autonomy system that can be put on any boat, explains Stilwell, although the group developed its own USV for testing purpose.
The team also performed an initial evaluation of a helmsman assist system that takes information from the sensing and autonomy system and displays it on a screen for a human operator who steers a boat. "We don't let the autonomy system steer the boat, but instead display a real-time map and the desired boat trajectory. This allows the boat to be operated at night and in all weather," says Stillwell. "It's also a baby-step toward full autonomy that we think will be adopted relatively quickly because it keeps a human in the loop."