Reduced Unmanned Surface Vehicle (USV) Motions For Reliable Recovery

Safe and reliable launch and recovery of small offboard assets is important to the concept of operations for the Littoral Combat Ship (LCS), as they are deployed to complete a wide range of missions. The LCS design specification requires launch and recovery of watercraft to be completed within fifteen minutes in conditions through Sea State 4. These operations are expected to be difficult because many of the missions will be conducted using unmanned surface vessels (USV). Several recovery concepts have been proposed. However, the development of a single, reliable system has been complicated by the pursuit of two LCS design variants with significantly different general arrangements and seakeeping properties. This proposal describes design and analysis of a wave monitoring and control system to reduce the relative motion between the USV and the LCS during the recovery process. The wave monitoring system will be used to provide initial conditions for forecasting conditions at the LCS to estimate calm periods as well as to provide input to the control system. The overall system is intended to work with existing recovery hardware for both over-the-side and stern launch and recovery systems.