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Coastal underwater archaeological sites are by nature dynamic, and often subject to disturbance from the action of waves, currents, sediment, and human activity. The need to document such sites comprehensively, accurately, and quickly has been the driving force behind technological advances in pre-disturbance site mapping since the 1960s. Certain challenges remain constant: the need for technology...
The international interdisciplinary field training of marine robotics and applications 'Breaking the Surface BtS started in 2009 as one of the two flagship dissemination activities of the EU-funded FP7 Capacities REGPOT-2008-1 project ‘De-veloping the Croatian Underwater Robotics Research Potential — CURE’. Three BtS field-trainings were organized as CURE activities (BtS2009, BtS2010 and BtS2011)...
The tragic Deepwater Horizon accident in the Gulf of Mexico in 2010 as well as the increase in deepwater offshore activity have increased public interest in counter-measures available for sub-surface releases of hydrocarbons. To arrive at proper contingency planning, response managers urge for a system for instant detection and characterization of accidental releases. Along these lines, this paper...
In this paper a comparative analysis of Mamdani and Sugeno type fuzzy autopilots for ships is given. Both autopilots have two inputs: the heading signal and the yaw rate signal, and only one output: command rudder angle. Input variable fuzzification, fuzzy associative memory (FAM) rules, and output set defuzzification are described. The control system for the course-keeping composed of the nonlinear...
The tragic Deepwater Horizon accident in the Gulf of Mexico in 2010 as well as increase in deepwater offshore activity have increased public interest in counter-measures available for sub-surface releases of hydrocarbons. Available remote-sensing techniques are efficient and well developed for surface disasters but they are not useful underwater. Along these lines, this paper analyzes application...
Posidonia oceanica (Neptune Grass) is an endemic species to the Mediterranean Sea. It forms dense and extensive green underwater meadows which provide important ecological functions and services and harbour highly diverse communities; as such it is identified as a priority habitat type for conservation under the EU Habitats Directive (Dir 92/43/CEE). Over the last decades many Posidonia oceanica meadows...
Establishing a cooperative heterogeneous robotic system comprising autonomous vehicles operating in air, on ground and on/under water is a challenging task that can significantly contribute solving complex problems related to environmental monitoring (e.g. prediction, prevention and recovery from natural disasters) and security (e.g. border control, fight against terrorism). This paper presents a...
Due to relatively slow dynamics of ROVs, pilot are given extra time to perform other tasks, such as inspections and arm operation. However, during multiple task handling, relevant information is typically dispersed on a number of screens overloading the pilot's visual channel. There is very little research examining the unique human-factors problems associated with unmanned underwater vehicles. Use...
This paper describes a modification of authors' previous work on virtual potential methods for planning and guidance of autonomous underwater vehicles (AUVs) along trajectories in ℝ2 and ℝ3. The modification replaces the algebraic sampling procedure of scalar potentials, performed in the previous algorithm in order to allow for the numerical approximation of the true local gradient of the potential,...
This paper demonstrates the use of self-oscillation identification experiments for tuning line following controllers for marine vehicles. Two approaches are described: first, when the controller output is yaw rate and second when controller output is reference heading. In the first case, low level controller is yaw rate while in the second it is heading controller. The identification by use of self-oscillations...
This paper describes the use of Kalman filtering in distance keeping for underwater vehicles. The vision-based distance keeping module has been mounted on a micro-ROV equipped with a camera. Distance from a plane-like obstacle is determined on the basis of the laser dot projections within the frame. Since these measurements are not reliable a Kalman filter is designed - unknown dynamic model parameters...
This paper describes an open source navigation system architecture for use in autonomous underwater vehicles. It is based on the mission oriented operating system proposed, published and programmed by ( (P. Newman, 2006), (P. Newman, 2008)). It is uniquely applicable for work-in-progress type and development-stage software and capability installation onto an AUV system. This applicability is achieved...
The problem of path planning for the autonomous vehicle in environment with moving and stationary obstacles is considered. An algorithm based on modified Kohonen rule and behavioural cloning (MKBC) is developed. The MKBC algorithm, as improvement of RBF neural network, uses the training values as weighting values, rather then values from the previous time instance. This enables an intelligent system...
A method for the trajectory planning of coordinated groups of UUVs, developed in authors' previous work is extended. The key points within the design patterns that must be used to implement the method in code are stressed. Rotors, vectorized quantities which introduce directionality, and thereby cause divergence from local minima, are introduced into the virtual potential algorithm. This development...
A major percentage of underwater operations takes place in structured environments. This article presents a low cost way for underwater vehicle positioning in places like pools, tanks, water towers etc. The developed application calculates a 2D position using only a simple scanning sonar and a digital compass. A user interface has also been designed for this purpose. Various modes of sonar scanning...
The Automarine Module is a cost effective method for transforming underwater remotely operated vehicles (ROVs) into autonomous underwater vehicles (AUVs), with a minimum development time needed. An existing ROV can easily be transformed in an AUV with no alteration of its interior, thus retaining the ROV mode of operation by simply disconnecting the module. The Automarine autonomization module described...
The ROV simulator was developed as modular structure with the possibility of connecting signals received from the real ROV. Programming language VRML helped in developing a 3D model of the ROV and the interaction between the ROV and the virtual world has been achieved. The kinematics of the ROV was implemented for simulator needs. The simulator menu offers different virtual environments. The simulator...
The work presented in this paper deals with the process of transfer function identification by using self-oscillation method (autotuning identification method). The algorithm is given in a general matrix form and some modifications are introduced. The modifications of the algorithm include augmentation of the initial algorithm for Type k systems, systems with delays and discrete-time systems. The...
This paper deals with an analysis of applicability, capabilities, benefits and pitfalls of using a virtual potential field approach to autonomously planning trajectories in non-communicating autonomous underwater vehicles (AUV-s). Virtual potentials represent an approach to this problem with cross-layer design features. Examples of different layers of control that can be achieved with the same fundamental...
The paper presents the procedure for identification of coupled mathematical models for underwater vehicles. The procedure is performed with the use of a simple laboratory apparatus that consists of a Webcam placed above the experimental pool. The video recording of the underwater vehicle in motion is then analyzed in order to obtain relative speeds within the camera frame. The experiment uses a simple...
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