Naval Surface Warfare Center

About: Naval Surface Warfare Center is a facility organization based out in Washington D.C., District of Columbia, United States. It is known for research contribution in the topics: Sonar & Radar. The organization has 2855 authors who have published 3697 publications receiving 83518 citations. The organization is also known as: NSWC.

Reducing Crane Payload Swing Using A Rider Block Tagline Control System

Abstract: This paper considers payload swing control of large, marine cranes using an active rider block tagline system (ARBTS). The contribution is the control system development and simulation comparison of the ARBTS approach to standard luff cranes without ARBTS. It is shown that the ARBTS control system off-loads boom actuation (luff) for ship motion cancellation. Thus, the boom can be used for its intended purpose of moving the load radially per the operator's command. For the simulation case considered, the maximum luff power decreases from 150 kW to 4 kW and the luff rope speed decreases from 0.9 m/s to 0.02 m/s. Application of this approach to existing offshore crane designs could increase their operational envelope, without increased power requirements or necessitating costly mechanical changes, permitting operations in rough sea conditions.

Real-time experimental control of a system in its chaotic and nonchaotic regimes

Abstract: Current model-independent control techniques are limited, from a practical standpoint, by their dependence on a precontrol learning stage. Here we use a real-time, adaptive, model-independent (RTAMI) feedback control technique to control an experimental system --- a driven magnetoelastic ribbon --- in its nonchaotic and chaotic regimes. We show that the RTAMI technique is capable of tracking and stabilizing higher-order unstable periodic orbits. These results demonstrate that the RTAMI technique is practical for on-the-fly (i.e., no learning stage) control of real-world dynamical systems.