Symbiotic Autonomy for Deep-Water Survey

Abstract

Coupling Long-Range Autonomous Underwater Vehicles (LRAUVs) with Unmanned Surface Vehicles (USVs) solves two of the key challenges associated with LRAUV missions: lack of real-time communication with the underwater asset and unbounded navigational error growth from dead reckoning. The coupling of LRAUVs and USVs effectively transforms the capabilities and accuracy of the LRAUV survey. A premier supplier of Unmanned and Autonomous Marine Systems led this development project working alongside a world-leading research center and developer of LRAUV systems. These two organizations were assisted by a leading developer of subsea acoustic positioning, communications and sonar systems, and a developer of software solutions for autonomous systems. The system architecture enables the USV to provide regular position updates to the LRAUV, removing the need for the LRAUV to surface from depth to update its internally calculated position. This cooperative localization scheme increases the efficiency and accuracy of LRAUV survey while reducing cost. The combination of the high-accuracy sonar systems on the LRAUV transiting close to the seabed and accurate position updates from the USV provides game-changing solutions for deep water surveys and Exclusive Economic Zone (EEZ) mapping globally. Due to the endurance and autonomy, this combination also allows for the possibility of executing remote subsea operations from a shore-based location. Eliminating the need for large ships to accompany the LRAUV significantly reduces data acquisition costs. The USV communicates with the LRAUV through two key methods: acoustics to provide short mission updates and positioning information, and optical communication technology to enable the system to upload the data from the survey sensors. With the data uploaded to the USV, it is then possible for the USV to process the data to enable summary data to be passed back through satellite or radio communications to a control center. In situations where data may indicate where gaps occur, or further investigation is required, an updated mission plan can be transmitted from the control center to the USV and then to the LRAUV. As onboard data processing techniques improve, the USV can be used to adaptively update the LRAUV's mission without human intervention. This transition to autonomy will save costs, reduce risk, and increase flexibility across a range of applications, including mine countermeasures, weapons testing, hydrography, environmental science, security, and surveillance.