On the adequacy of Adams-Bashforth sampled-data models for characterizing complex underwater-vehicle dynamics with noisy measurements

In this paper the adequacy of high order interpolation-based approaches to describe highly perturbed complex dynamics in discrete time was analyzed. The analysis establishes features of the approaches related to modularity, consistency with the model order and the sampling times, and accuracy in disturbed contexts with noisy measurements. A detailed study of the sensitivity of local prediction errors under a high signal-to-noise ratio is carried out with analytical expressions in dependence of physical coefficients of the vehicle. The different interpolation-based approaches were illustrated with simulations using from an AUV-like (Autonomous Underwater Vehicle) system with a few degrees of freedom (DoF), to a ROV (Remotely Operated Vehicle) model of 6 DoF with complex navigation paths.Sociedad Argentina de Informática e Investigación Operativa (SADIO

A sensor for vision-based navigation in underwater path tracking with color and edge segmentation

This paper aims the design and implementation of a visionbased sensor for navigation of underwater vehicles with adaptive attributes. The objective pointed out is a sensor for tracking of underwater lines. The sensor employs a basic structure with a pixel-wise AND operation of binarized frames of separated channels HSV and an edgesegmented frame. The basic sensor performs well by good illuminated scenes. By significant drops of luminance, the efficiency falls. So an adaptive sensor is proposed over the basic structure. It operates on the brightness channel carrying out a maximization of contains in the accumulator bins of a Hough transformation. It has proven to enhanced the identification of the tracked line increasing the success rate.Sociedad Argentina de Informática e Investigación Operativa (SADIO

A sensor for vision-based navigation in underwater path tracking with color and edge segmentation

This paper aims the design and implementation of a visionbased sensor for navigation of underwater vehicles with adaptive attributes. The objective pointed out is a sensor for tracking of underwater lines. The sensor employs a basic structure with a pixel-wise AND operation of binarized frames of separated channels HSV and an edgesegmented frame. The basic sensor performs well by good illuminated scenes. By significant drops of luminance, the efficiency falls. So an adaptive sensor is proposed over the basic structure. It operates on the brightness channel carrying out a maximization of contains in the accumulator bins of a Hough transformation. It has proven to enhanced the identification of the tracked line increasing the success rate.Sociedad Argentina de Informática e Investigación Operativa (SADIO

A Real-Time Approach to Achieve Maximal Autonomy of Autonomous Underwater Vehicles in the Presence of Perturbing Flow Field

In this paper a preliminary study of optimal energy systems for autonomous underwater vehicles is presented. A method is developed for achieving maximal autonomy. A general algorithm was developed for the navigation in 6 degrees of freedom in a non-conservative flow field. It is shown that missions with selective starting point beginning with the direction of the flow are much more favorable for the autonomy.Sociedad Argentina de Informática e Investigación Operativ

Análisis de Oscilaciones No-Lineales en Sistemas Complejos de Mecánica e Hidrodinámica - Herramientas y Metodología

[ES] En este trabajo se presenta una metodología de análisis y simulación interactiva de sistemas dinámicos oscilantes de mecánica e hidrodinámica, involucrando a distintas herramientas especializadas en elementos finitos, dinámica de multi-cuerpos y análisis de bifurcaciones. La interconexión de herramientas las lleva a cabo el usuario mediante el desarrollo de programas propios para cálculo simbólico a partir de ecuaciones básicas de la dinámica. La estructura de la metodología responde al objetivo de concretar el estudio de estabilidad y comportamiento de dinámicas complejas, previos a una experimentación en laboratorio. Se presentan diversos ejemplos de aplicación en la Ingeniería Oceánica.Los autores agrade-cen al CONICET, SETCIP, DAAD y DIEC-UNS por elfinanciamiento de este trabajo.Jordán, MA.; Bustamante, JL. (2010). Análisis de Oscilaciones No-Lineales en Sistemas Complejos de Mecánica e Hidrodinámica - Herramientas y Metodología. Revista Iberoamericana de Automática e Informática industrial. 1(3):63-77. http://hdl.handle.net/10251/146585OJS63771

Evaluation of Human Control in Teleoperation of Underwater Vehicles : Compative Study in Time and Frequency Domains

In this paper a study of teleoperation of remotely operated vehicles is carried out employing two sources of video, the inboard image and external camera. Additionally, a modeling of the human behavior during path tracking is performed. For this goal a structure of a nested control loop is supposed. The inner loop involves a high-performance digital controller, while the outer loop is composed by the human teleoperation. For modeling the human control actions a PID-like controller is proposed. The identification of the parameters of the PID is carried out in both domains, time and frequency. Features of these studies are based on experiments designed by simulations and on-line interaction of the teleoperator by means of a joystick.Sociedad Argentina de Informática e Investigación Operativ

On the adequacy of Adams-Bashforth sampled-data models for characterizing complex underwater-vehicle dynamics with noisy measurements

In this paper the adequacy of high order interpolation-based approaches to describe highly perturbed complex dynamics in discrete time was analyzed. The analysis establishes features of the approaches related to modularity, consistency with the model order and the sampling times, and accuracy in disturbed contexts with noisy measurements. A detailed study of the sensitivity of local prediction errors under a high signal-to-noise ratio is carried out with analytical expressions in dependence of physical coefficients of the vehicle. The different interpolation-based approaches were illustrated with simulations using from an AUV-like (Autonomous Underwater Vehicle) system with a few degrees of freedom (DoF), to a ROV (Remotely Operated Vehicle) model of 6 DoF with complex navigation paths.Sociedad Argentina de Informática e Investigación Operativa (SADIO

A vision-based controller for path tracking of autonomous underwater vehicles

This paper aims a design of a vision-based controller for autonomous underwater vehicles (AUVs). The control system performs the path following of a line on the seafloor and tunes automatically the cruise kinematics for the advance.The navigation process rests upon a sensor which estimates the relative vehicle position from the perspective of the camera directly without the need of employing camera models for estimating physical variables. For the state estimation, image processing in real time is employed. The control strategy is developed in the state space of pure vision coordinates. The strategy points to reach rapidly favorable configurations of the AUV and afterwards to pursue a perfect alignment with the line. Experiments of the real subaquatic world are presented.Sociedad Argentina de Informática e Investigación Operativa (SADIO