Title: The NaviGator Autonomous Maritime System
Author(s): Andrew Gray, Zach Goins, Eric Schwartz
Abstract: Working with autonomous underwater vehicles (AUV) is an involved process that requires a significant amount of manpower, can be time consuming, and is expensive. Methods need to be discovered that will streamline the process, reduce man power, and increase efficiency. Manpower can be reduced by utilizing unmanned surface vehicles (USV) during AUV operations. USVs have great endurance and can perform some operations that typically require human intervention, such as launching and recovering AUVs. However, the process of launching and recovering an AUV takes time which affects the efficiency of the AUV mission and can impact the overall operational schedule. The operator needs to decide when the AUV’s mission is complete and when to recover the system. Ideally, this decision would be made based on the submarines data from onboard sensors. However, because of the lack of ability in transmitting large amounts of data quickly underwater, the decision to recover the AUV is made based upon a pre-determined mission with no real-time feedback to the user. These missions can run from hours to days, leaving the operator in the dark with regards to what the AUV is “seeing” until the vessel surfaces. The proposed system helps AUV operators by utilizing USVs to analyze sensor data more rapidly and thereby eliminating the need to recover the AUV. By establishing an underwater link between the USV and AUV using a tether, large amounts of data can be quickly transmitted to the user in aid of deciding the AUV’s next mission. The link between the two vessels is initiated by the USV deploying the tether to the approximate depth of the AUV. A water tight capsule is attached to the end of the tether and contains electronics that enable communication between the AUV and USV. The AUV is summoned using ultrasonic transducers from the end effector. Using just SONAR, the AUV blindly approaches the capsule until the submarine can see the end effector’s LEDs using submarine cameras. Once in visual range, the AUV switches to visual homing and docks with the watertight pod. Data is then transferred from the submarine to the USV’s computer (through the pod) utilizing the Ethernet component of the tether. The data can then be wirelessly transmitted to the operator for analysis. The proposed system (now under development) increases AUV operational efficiency by allowing the transmission of large quantities of data without the surfacing and recovery of the submarine. The user can quickly analyze the data and wirelessly transmit the next mission to the USV which passes the commands to the AUV through the tether. Missions can be broken into smaller run times allowing for more directed activities. By eliminating the need for the AUV to surface, significant amounts of time can be saved, reducing manpower and costs.