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

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

Effect of Control System Augmentation on Handling Qualities and Task Performance in Good and Degraded Visual Environments

In June 2013, NASA and the U.S. Army jointly conducted a simulation experiment in the NASA-Ames Vertical Motion Simulator that examined and quantified the effects of limited-authority control system augmentation on handling qualities and task performance in both good and degraded visual environments (DVEs). The vehicle model used for the experiment was the OH-58D with similar size, weight and performance, and the same 4-blade rotor system as the Bell 407 civilian helicopter that is commonly used for medical evacuation and emergency medical services. The control systems investigated as part of this study included the baseline aircraft Rate Command system, a short-term Attitude Command/Attitude Hold system that uses lagged-rate feedback to provide a short-term attitude response, Modernized Control Laws that provide an Attitude Command/Attitude Hold control response type, and Modernized Control Laws with an additional Position Hold function. Evaluation tasks included the ADS-33 Hover, Sidestep, Acceleration/Deceleration, and Pirouette Mission Task Elements, as well as a new proposed Emergency Medical Services task that includes an approach and landing at a minimally prepared remote landing site. Degraded visual environments were simulated with night vision goggles and an unaided night scene. A total of nine experimental test pilots participated in the four-week simulation experiment. Data recorded during the evaluation included Cooper-Harper handling qualities ratings, Bedford Workload scale ratings, and task performance. The Usable Cue Environment (UCE) was measured for this simulation experiment, and found to be UCE equals 1 in good visual environments and UCE equals 2 in degraded visual environments with night vision goggles. Results showed that handling qualities ratings were improved with a control system providing short-term attitude response over a rate command system, although the improvements were not sufficient to produce Level 1 handling qualities in degraded visual environments. Results for an Attitude Command/Attitude Hold control system showed that borderline Level 1 handling qualities could be achieved in degraded visual environments, and the 10 percent authority stability augmentation system was adequate to obtain these handling qualities ratings

A Berger type normal holonomy theorem for complex submanifolds

We prove a kind of Berger-Simons' Theorem for the normal holonomy group of a complex submanifold of the projective spac

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

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