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Semi-Autonomous, Reliable, Safe Recovery of the Remote Multi-Mission Vehicle (RMMV) in Various Sea States


OBJECTIVE: The objective is to develop technology for an autonomous, reliable, and safe system for Littoral Combat Ship INDEPENDENCE Variant to recover the RMMV in various sea states. DESCRIPTION: The Remote Multi-Mission Vehicle (RMMV), a Snorkeler Class Unmanned Surface Vehicle (USV) per reference 1, is a semi-autonomous, semi-submersible vehicle launched and recovered from the Littoral Combat Ship (LCS). As stated in reference 2, the RMMV is seven meters in length with a diameter of 1.1 meters and has four degrees of freedom (roll, pitch, yaw, heave). The effect of roll particularly has been evident during RMMV recovery testing on the LCS INDEPENDENCE Variant. The RMMV recovery operations have not been consistently well-timed or reliably repeatable by the coordinated effort of the final two operators controlling the RMMV and the mechanism to capture the RMMV, especially under varying sea state conditions. Slow human response times, leading to misalignment of the RMMV to the capture mechanism, could result in damage to the vehicle, capture mechanism, and other recovery equipment. The facilitation of autonomous recovery can save time, fuel, and manpower aboard their host platforms, all of which lead to cost savings in addition to risk mitigation. The current process to recover an operational tactical RMMV consists of multiple steps and the final coordination of two operators in the ship"s mission bay. One operates the Remote Operator Pack (ROP), a portable control interface in the mission bay. The other operates the Twin Boom Expandable Crane (TBEC). Prior to their involvement, a human operator in the ship"s Mission Control Room (MCR) assumes control of the RMMV and directs it to return to the ship using a combination of over the horizon (OTH) and line of sight (LOS) communications. As the RMMV approaches, the MCR operator confirms visual acquisition of the target when it is approximately 1000 yards aft of the ship. The MCR operator then transfers control of the RMMV to the ROP operator. Both the ROP operator and the TBEC operator maintain a visual lock on the RMMV. The ROP operator closes the distance between the RMMV and the ship. While this is occurring, a tow line loop is released from the mission bay stern door, such that it floats on the surface, by line handlers stationed at the mission bay stern doors. While observing the mast of the RMMV approaching the tow line, the ROP operator commands the RMMV to surface and the tow line loop is reeled in until it is caught by the tow hook on the RMMV. This line provides a constant restraint during recovery. When the tow line is hooked, the ROP operator puts the vehicle propulsion into neutral and the tow cable is reeled into the ship, closing the gap between the RMMV and the ship. During this time, the ROP operator provides commands to the RMMV control surface assemblies to keep the RMMV stable as it traverses the turbulent wake of the LCS During the recovery process, the aft doors of the LCS mission bay are open and the TBEC operator extends the Crane from the stern of the LCS, with the Capture Spine Assembly (CSA) attached. When the RMMV is stable and under the CSA, the TBEC operator lowers the CSA to mate to a spine on the RMMV and raise the vehicle from the water. What is desired is automation of key operations of the ROP and TBEC portions of the recovery process to provide quicker response times than the human operators can achieve while trying to compensate continually for changing turbulent wake field conditions. The goal for the ROP portion is for the RMMV to pose in a steady state position beneath the CSA, primarily by limiting RMMV roll while under tow from the LCS. Automation in the TBEC operation would lower the CSA in a controlled and safe manner to reliably capture the RMMV within the optimal range of relative motion of the mechanism and the vehicle. General autonomy references are provided by References 3 and 4. A significant amount of research has been conducted on automating launch and recovery of remotely operated vehicles (ROVs) and unmanned vehicles; however, no practical solutions have been generally accepted by industry or government organizations. Recovery operations continue to be manpower intensive. Reference 5 provides additional information important to understanding the problem and to developing potential solutions PHASE I: The company will develop concepts for the semi-autonomous recovery of RMMV in various sea states in light of the design constraints identified above. The company will investigate an innovative solution in meeting Navy needs and will establish that the solution can be feasibly developed into a useful product for the Navy. Feasibility will be established by analytical modeling and simulation. The company shall document the proposed method of autonomous recovery. The company shall describe the approach it envisions for installing the proposed hardware and software on the LCS Independence variant and the RMMV. The company shall describe the essential characteristics of the recovery controller supported by feasibility simulations of recovery. The small business will provide a Phase II development plan with performance goals and key technical milestones that will address technical risk reduction. PHASE II: Based on the results of Phase I and the Phase II development plan, the small business will develop a prototype for evaluation as appropriate. The key software and hardware components of the prototype will be initially tested in a lab and pier side and evaluated by the company to determine their capability to meet the performance goals defined in the Phase II development plan and the Navy requirements for the Semi-autonomous recovery of RMMV in various Sea States. The company will then construct a prototype system and support Navy demonstration and evaluation of the system performance through prototype testing and evaluation on an Independence-class LCS (or equivalent alternative) and an RMMV over the required range of parameters including numerous deployment cycles. The company will use the evaluation results to refine the prototype into a design for a first-order production unit that will meet Navy requirements. The company will prepare a Phase III development plan to transition the technology to Navy use. PHASE III: If Phase II is successful, the company will be expected to support the Navy in transitioning the technology for Navy use. The company will produce a sensor suite, controller, and integration plan for the semi-autonomous recovery of RMMV in various Sea States. The company will support the Navy for test and validation to certify and qualify the system for Navy use. PRIVATE SECTOR COMMERCIAL POTENTIAL/DUAL-USE APPLICATIONS: A lucrative market current exists for at-sea recovery of Autonomous Unmanned Vehicles (AUVs). Current commercial recovery procedures involve stopping both host platform and AUV and hooking lines between the two vehicles. Institutions such as Woods Hole Oceanographic Institute and private industries supporting the petroleum industry all use AUVs and conduct numerous launch and recovery operations every year. The minimal installation of hardware on an AUV is seen as an advantage since most of the installation and integration of equipment can take place on the host platform performing the recovery, providing a stable, dry, installation friendly base. REFERENCES: 1."The Navy Unmanned Surface Vehicle (USV) Master Plan."23 July 2007. U.S. Navy. 29 February 2012. 2."Remote Multi-Mission Vehicle (RMMV) Fact Sheet."Department of the Navy Research, Development, and Acquisition. Program Executive Office, Littoral Combat Ships (PEO LCS), 29 February 2012. 3. T. Huntsberger,'Intelligent Autonomy for Unmanned Surface and Underwater Vehicles,'Proc. OCEANS"11 MTS/IEEE Kona, Kona, HI, September 19-22, 2011. 4. Intelligent Vehicle Systems: A 4D/RCS Approach (Editors: R. Madhavan, E. Messina, and J. Albus), Nova Science Publishers, Inc., Dec 2006. 5."Additional Guidance for Semi-Autonomous, Reliable, Safe Recovery of the Remote Multi-Mission Vehicle (RMMV) in Various Sea States."(Document will be made available on the SBIR Interactive Topic Information System (SITIS) after Pre-Release.)
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