Four propellers submarine drone modelling in a real environment

<span lang="EN-US">In order to reduce the hydrodynamic dampers and mechanical elements as rudders, we have in our previous publications proposed our architectural solution of an ROV with only four thrusters without rudders or diving bars. In the results we have justified the choice of the arrangement of the thrusters. Also, we have started the kinematic and dynamic studies of the marine robot and we have especially demonstrated by using the mathematical model under MATLAB in the last publication, that this ROV can move in a perfect environment without gravity or hydrodynamic dampers. In this article, we will study the behavior of this marine vehicle in a real environment with gravity and hydrodynamic dampers and we will view if this architectural solution can really allow the ROV to move and execute the given directional instructions.</span>

Blade Cup Method for Cavitation Reduction in Marine Propellers

Energy efficiency has become more important in every industry and daily life. Designing and building a more efficient marine vehicle can lead to lower fuel consumption and a longer lifetime for the components of the vehicle. Erosion caused by cavitation reduces the service life of the propeller and the related components in the propulsion and maneuvering system. Reducing cavitation leads to a longer life for these components. This paper aims to explain and investigate propeller blade cup as a cavitation reduction method for marine propellers. A cavitating no-cup propeller is created and analyzed then the cupped version of this propeller is generated and analyzed to compare with the no-cup propeller. Cavitation results of these propellers are investigated. In addition, the thrust, torque, and efficiency of the propellers are compared.

Persistent Mobile Ocean Observing: Marine Vehicle Highways

Persistent mobile ocean observation platforms, supported by arrays of subsea marine vehicle service stations, will enable direct study of oceanographic and geological processes that, due to their transient nature and spatiotemporal variability, are not well understood. These include, but are not limited to, ocean-seafloor interactions and crustal ecosystems, mid-ocean ridge volcanism, coastal circulation and shelf ecosystems, reef health, and arctic sea-ice interaction. Further, certain types of subsea events, such as erupting submarine volcanoes, instabilities in methane hydrate deposits, marine mass-wasting events, turbidite flows, the ecological impacts of major earthquakes, breaking internal waves, the fate of mid-water vortices, and episodes of anoxic upwelling, can be energetic, transient, and unpredictable, often having unverifiable consequences. These cannot be readily detected, characterized, or quantified owing to the difficulty of anticipating the onset of such phenomena. The intractability of launching major sea-going assets with short lead times to capture and document such evanescent system-level processes from beginning to end means that our understanding of these and related processes is not readily expandable with current oceanographic tools.Marine Vehicle Highways (MVHs) will change the way ocean science is conducted by making temporally and spatially distributed data sets more attainable and accessible, opening the door for broader participation in transformative ocean science.

DESIGN CONTROL OF SURFACE MARINE VEHICLE USING DISTURBANCE COMPENSATING MODEL PREDICTIVE CONTROL (DC-MPC)

This research studied ship motion control by considering four degrees of freedom (DoF): yaw, roll, sway, and surge in which comprehensive mathematical modeling forming a nonlinear differential equation. Furthermore, this research also investigated solutions for fundamental yet challenging steering problems of ship maneuvering using advanced control method: Disturbance Compensating Model Predictive Control (DC-MPC) method, which based on Model Predictive Control (MPC). The DC-MPC allows optimizing a compensated control then consider sea waves as the environmental disturbances. Those sea waves influence the control and also becomes one of the constraints for the system. The simulation compared the varying condition of Horizon Prediction (Np) and another method showing that the DC-MPC can manage well the given disturbances while maneuvering in certain Horizon Prediction. The results revealed that the ship is stable and follows the desired trajectory

Control PID basado en odometría visual monocular a un vehículo de superficie marino

The aim of this work is to study the behavior of a marine vehicle applying vision-based control. We use a DMVO algorithm (Direct Monocular Visual Odometry) that is based at the feature extraction of two image frames taken consecutively at two continuous tame frames in order to estimate a marine vehicle’s position; vehicle’s dynamics are modeled without external perturbations and therefore apply a vision based Proportional Integral Derivative (PID) control for the study of its behavior through simulations using computational tools to simulate a 3D scenario and get the matrix that contains the image from the inertial frame of reference view from the vehicle. First we need a static scenario that contains reference points such that we are able to apply the proposed vision based PID control; the virtual scenario was designed at the MATLAB’s virtual world editor that let us add sensors such as cameras, and set their parameters for make the study and simulations such as path following.