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This paper presents a robotics vision-based system for an underwater pipeline and cable tracker. This system is introduced to improve the level of automation of underwater remote operated vehicles (ROVs) operations which combines computer vision with an underwater robotics system to perform target tracking and intelligent navigation. This study focuses on developing image processing algorithms and...
In this paper we present a relatively novel methodology, based on backstepping procedure, focused on solving the tracking control problem in ships whose dynamics is characterized by a nonlinear model. The sea trials of a liquefied natural gas (LNG) carrier show that the Norrbin model is capable of representing appropriately the variation of the course when a change on the rudder angle is applied....
The northern South China Sea (SCS) including the Luzon Strait, from around 19deg to 22degN latitude and from 114deg to 122degE longitude, is an ocean area where energetic internal waves occur frequently. In this study, satellite ocean color products from SeaWiFS (Sea-viewing Wide Field-of-view Sensor) and MODIS (Moderate Resolution Imaging Spectroradiometer) including true color and chlorophyll images...
This work presents a system for 3D reconstruction from underwater images or video. Aside from a camera in an underwater housing, no special equipment is required. However, if navigational data is available, it is utilized in the algorithm. The algorithm is in essence a classical structure from motion approach, which is adapted to account for the special imaging conditions. Hence, there is no need...
An approach to oil spill detection is presented using optical satellite images. Features from SAR literature are studied. Different statistical and neural network-based classifiers are used in order to perform a supervised automatic classification and their performances are compared. The promising results achieved on the collected dataset encourage a further analysis of the potential of the optical...
In the previous conference a new vehicle attitude estimation method was proposed using imaging sonars with Hough transformation for noisy sonar images. The method estimates onboard sonar attitude parameters from the location of the reference plane in the sonar image. In this paper a new rotation parameter estimation is introduced using these attitude parameter time variations. It does not require...
In this study, we present two types of simulation models that consist of a sediment layer, a crust layer, and a sloped interface that are marked as seismic velocity discontinuities. Seismometers are aligned on the seafloor. One model has only surface seismic sources and the other has buried seismic sources that are equivalent to natural earthquakes. For every shot or earthquake, we obtain either refracted...
This paper describes the early development of autonomous vehicle for undersea exploration at depths of as much 1000 m. It is to combine several methods of propulsion, including wheels and legs.
Safety of shipping is a growing concern. The causes of shipping casualties are various, while over 30% of the casualties are due to bad weather. Heavy sea state and severe weather conditions have caused the loss of more than 200 large cargo vessels within 20 years between 1981 and 2000. Remote sensing techniques, particularly the active microwave radar provides global sea surface observations for...
This paper presents a novel sensing method for navigation of autonomous underwater vehicles, AUVs, through pipelines to conduct autonomous internal inspection. Unlike remotely operated pipe inspection robots, AUVs do not have an umbilical cable and so they can easily maneuver through bent sections of pipelines and the distance they can cover is not restricted by the length of the cable. Presently...
It is well established that path loss in the underwater acoustic channel is dependent on the transmission distance and signal frequency utilized, thereby causing the capacity to be dependent on transmission distance. It has been demonstrated that this dependence of capacity can lead to significant effects on the design of topologies for underwater acoustic networks. However, recent research in the...
The purpose of this research is to provide an underwater glider with high manoeuvrability. This paper deals with the modelling and motion simulation of an experimental vehicle named `ALEX' as a test-bed for an underwater glider with independently controllable main wings. ALEX was designed to realise high performance manoeuvrability. The main wings, rudder, elevator, movable balance weight and vent-blow...
In this paper, we develop a coordination mechanism for multiple autonomous underwater vehicles (AUVs) and a single unmanned aerial vehicle (UAV) cooperatively performing a ocean exploration mission. The UAV and the AUVs have limited sensor and communication constraints. The AUVs are deployed in the ocean and surface when their mission leg is completed. The UAV flies over the AUV, acquires the information...
This paper introduces a simulation tool (ldquoHISSrdquo) to assess the level of underwater security in civilian harbour installations. The simulator is based on a geographical information system, and on acoustic and magnetic underwater sensor models. The final objective of the simulator is to improve port security verifying the impact of new sensors and modification in the sensors placement in the...
It is now common to quasi-automatically generate acoustic bathymetry and optical mosaics from instrumented Autonomous Underwater Vehicles (AUVs). However, further analysis and interpretation of gathered data is needed to address tasks such as habitat characterization and monitoring. This analysis stage is performed by human experts which limits the amount and speed of data processing. While it is...
The use of unmanned marine robotic vehicles in bathymetric surveys is discussed. This paper presents recent results in autonomous bathymetric missions with the ROAZ autonomous surface vehicle. In particular, robotic surface vehicles such as ROAZ provide an efficient tool in risk assessment for shallow water environments and water land interface zones as the near surf zone in marine coast. ROAZ is...
This work presents the integration of obstacle detection and analysis capabilities in a coherent and advanced C&C framework allowing mixed-mode control in unmanned surface systems. The collision avoidance work has been successfully integrated in an operational autonomous surface vehicle and demonstrated in real operational conditions. We present the collision avoidance system, the ROAZ autonomous...
We present a technique for the integration of data from a ship based multibeam along with multibeam and stereo images gathered from an AUV. The novelty of the proposed technique is the ability to integrate data-sets at different resolutions to produce one consistent model that captures not only high resolution images of the seafloor but sweeping geological features that span kilometers.
In this project an algorithm to generate a single image of an entire water pipe's inside wall was developed. An Autonomous Underwater Vehicle (AUV) equipped with a fish-eye camera will be deployed to dive through the pipe and take pictures of its inside wall. The algorithm was implemented that maps such pictures to the three dimensional model of the water pipe and based on that, generates the image...
A method is introduced where blind source separation (BSS) of acoustical sources is combined with spatial processing to remove non-Gaussian, broadband interferers from space-time displays such as bearing track recorder (BTR) displays. This differs from standard techniques such as placing nulls in the direction of interferers. The algorithm performance is compared to adaptive beamforming techniques,...
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