Virtual Environment for Ships and Ship-Mounted Cranes

1. Virtual Environment for Ships and Ship-Mounted Cranes Ali H. Nayfeh Lance Arsenault, Dean Mook, and Ron Kriz Virginia Polytechnic Institute and State University DURIP Supported by the Office of Naval Research Dr. Kam Ng, Technical Monitor

2. MURI on Nonlinear Active Control of Dynamical Systems Supported by the Office of Naval Research Dr. Kam Ng Technical Monitor

3. Objectives of the MURI Develop a unified control methodology and control strategy for nonlinear dynamical systems and processes • Develop controller architecture and control algorithms for both high- and low-level controls for undersea vehicles, shipboard crane operation, and large-scale power electronic systems • Develop simulations of ship hydrodynamics and control methodologies that can be used to conceptualize advanced hull forms

4. Concentration Areas Unmanned Undersea Vehicles (UUV) Power Electronics Building Blocks (PEBB) Control Algorithms Control Methodology & Controller Architecture Shipboard Crane Operation Ship Motion Prediction Simulation & Control

5. Simulator Objectives • State-of-the-art physical models are used to develop a state-of- the-art Ship and Crane Simulator Testbed at the Virginia Tech CAVE • Testbed serves as a platform for testing ship and crane technologies • Testbed can be used to test the boresight of sensors and data-link margins

6. Virginia Tech CAVE • Visual image generation system with three pipes • Image generation computer • Head motion tracking system • Image display system • Four high-resolution projectors • Three projection walls and one projection floor • Liquid crystal eyes stereoscopic system • Sound simulation system • Six-degree-of-freedom motion base

7. CAVE Capability • Computer-generated multi-sensory information is rear projected in stereo onto the walls and floor of the CAVE and viewed with stereo glasses • Head motion tracking system allows the viewer to walk around the system • The viewer could see what amounts to an action theatre of one or more ships • The theatre extends beyond the walls of the CAVE • The viewer experiences all design variables in concert • Engineers can create and evaluate system prototypes

8. Simulator Characteristics • Moving platform • Simulates the motion of a ship • Permits a virtual movement about and inspection of the ship and experiencing its motion in high sea states • Crane operator functions in a highly realistic virtual environment complete with • High-fidelity 270 degree scene visualization • Ambient sound • Base motion • Physical control console • Chair and cupola

9. Visualization of Ship Motion and Control • Large-amplitude (nonlinear) ship motion • Simulations of ship hydrodynamics • Motion control systems • Anti-roll tanks • Anti-roll weights • Hull-mounted fins • Hull-mounted cavitating spoilers • Hybrid designs with rudder action and course keeping • Evaluation of different hull designs

10. Destroyer Model in a Regular Head Sea-Only Pitch Motion is Directly Excited

11. Cargo Transfer at Sea

12. 3D Uncontrolled Response • Animation is faster than real time. • 2° Roll at wn. • 1° Pitch at wn. • 1 ft Heave at 2wn.

13. 3D Controlled Response • Animation is faster than real time. • 2° Roll at wn. • 1° Pitch at wn. • 1 ft Heave at 2wn.

14. 3D Controlled ResponseSlew Maneuver • Animation is faster than real time. • 2° Roll at wn. • 1° Pitch at wn. • 1 ft Heave at 2wn.

15. Built 3-DOF Ship Motion Simulation Platform General Pitch, Roll, and Heave capability Sinusoidal excitations in present results Equipped 1/24th scale model of T-ACS crane (NSWC) with motor and cable Crane control executed on PC Experimental Demonstration

16. Uncontrolled Response • 1° Roll at wn. • 0.5° Pitch at wn. • 0.5 in Heave at 2wn.

17. Controlled Response • 1° Roll at wn. • 0.5° Pitch at wn. • 0.5 in Heave at 2wn.

18. Controlled Response • 2° Roll at wn. • 1° Pitch at wn. • 0.5 in Heave at 2wn.

19. Controlled ResponseSlew Maneuver • 1° Roll at wn. • 0.5° Pitch at wn. • 0.5 in Heave at 2wn.

20. Controlled ResponseSlew Maneuver • 2° Roll at wn. • 1° Pitch at wn. • 0.5 in Heave at 2wn.

21. Motion Base

22. System Software Design *complete SharedMemory system state DTK Server memory manager command Crane Control operator filter Motion Base com motion base base state motion joysticks Operator Input joysticks/buttons buttons crane Fun Filter motion filter MotionTracker non-magnetic head wand ship Render draw visual graphics Motion Base controller sensors Crane Model crane dynamics LAMP ship dynamics

23. SharedMemory system state command base state motion joysticks Sound simulator driven buttons crane head wand ship graphics

24. VT CAVE

25. emulate real devices GUIs Powered by DIVERSE Desktop simulator of the VR Crane Ship Simulator

26. Progress • CAVE running in new building • With motion base • Or flat floor • Crane motion

28. Platform for Testing Technologies • Response of (individual and multiple) ships in a dynamic sea environment • Integrated ship-motion prediction and control • Determination of how different hull forms operate in various sea states • Control of cargo handling aboard ships in high sea states • Animation and visualization of ship and crane systems in a dynamic sea environment • Virtual prototyping of ships and cranes, including the input of operators • Ship- and crane-operator training • Collaborative environment

29. http://thor.sv.vt.edu/crane/