Experimental Study of Command Governor Adaptive Control for Unmanned Underwater Vehicles

2019 ◽  
Vol 27 (1) ◽  
pp. 332-345 ◽  
Author(s):  
Charita Darshana Makavita ◽  
Shantha Gamini Jayasinghe ◽  
Hung Duc Nguyen ◽  
Dev Ranmuthugala
Keyword(s):  
Experimental Study ◽  
Adaptive Control ◽  
Underwater Vehicles ◽  
Unmanned Underwater Vehicles

An Integrated, Computer-Based Method for Rapid-Prototyping Weapons-Scale Marine Propulsors Using Stereolithography

1997 ◽  
Author(s):  
Robert M. Koch
Keyword(s):  
Rapid Prototyping ◽  
Design Process ◽  
Structural Design ◽  
Development Time ◽  
Underwater Vehicles ◽  
Process Efficiency ◽  
Two Phase ◽  
Unmanned Underwater Vehicles ◽  
Reduce Development Time ◽  
Computer Based

Abstract The present work describes an integrated, two-phase computer-based method for fabricating marine propulsors using stereolithography. This new methodology seamlessly integrates stereolithography rapid prototyping techniques with the hydrodynamic design, structural design, and prototype testing of advanced marine propulsors in order to greatly increase the design process efficiency and reduce development time. Its use as applied to the design, fabrication, and testing of advanced propulsor prototypes for small weapon’s-scale undersea vehicles (e.g., Unmanned Underwater Vehicles (UUVs), lightweight and heavyweight torpedoes, etc.) is described in order to demonstrate specific strengths of the new method.

A Ballast System for Automated Deep-Sea Ascents

2016 ◽  
Author(s):  
Matthias Golz ◽  
Florin Boeck ◽  
Sebastian Ritz ◽  
Gerd Holbach
Keyword(s):  
Environmental Impact ◽  
Environmental Contamination ◽  
Pressure Vessel ◽  
Deep Sea ◽  
Underwater Vehicles ◽  
Compressed Air ◽  
Hydraulic Pump ◽  
Unmanned Underwater Vehicles ◽  
The Past ◽  
Set Up

The efforts to discover the world’s oceans — even in extremely deep-sea environments — have grown more and more in the past years. In this context, unmanned underwater vehicles play a central role. Underwater systems that are not tethered need to provide an apparatus to ensure a safe return to the surface. Therefore, positive buoyancy is required and can be achieved by either losing weight or expanding volume. A conservative method is the dropping of ballast weight. However, nowadays this method is not appropriate due to the environmental impact. This paper presents a ballast system for an automated ascent of a deep-sea seabed station in up to 6000 m depth. The ballast system uses a DC motor driven modified hydraulic pump and a compressed air auxiliary system inside a pressure vessel. With regard to the environmental contamination in case of a leakage, only water is used as ballast fluid. The modification of an ordinary oil-hydraulic radial piston pump and the set-up of the ballast system is introduced. Results from sea trials in the Atlantic Ocean are presented to verify the functionality of the ballast system.

scholarly journals Determining Bottom Reflectance and Water Optical Properties Using Unmanned Underwater Vehicles under Clear or Cloudy Skies

2006 ◽  
Vol 23 (2) ◽  
pp. 314-324 ◽  
Author(s):  
David C. English ◽  
Kendall L. Carder
Keyword(s):  
Optical Properties ◽  
Water Column ◽  
Optical Sensors ◽  
Light Field ◽  
Field Measurements ◽  
Underwater Vehicles ◽  
Unmanned Underwater Vehicles ◽  
Cloudy Weather ◽  
Sea Grass ◽  
Ocean Color Imagery

Abstract An unmanned underwater vehicle (UUV) with hyperspectral optical sensors that measure downwelling irradiance and upwelling radiance was deployed over sandy bottoms, sea grass patches, and coral reefs near Lee Stocking Island, Bahamas, during the Coastal Benthic Optical Properties (CoBOP) program of 2000. These deployments occurred during both sunny and cloudy weather. If the rate of irradiance change due to cloud cover is slight, then the inclusion of a variable cloudy-irradiance factor will allow a reasonable estimation of water column absorption. Examination of data from a deployment in May 2000 under cloudy skies shows that the combination of hyperspectral light-field measurements, knowledge of the UUV's position in the water column, and a cloudy-irradiance factor permits consistent estimations of bottom reflectivity to be made from UUV measured reflectances. The spatial distribution of reflectance estimates obtained from a UUV may be useful for validation of airborne ocean color imagery.

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