Diseño del sistema de navegación en inmersión del vehículo Guanay II para aplicaciones de detección y seguimiento de vertidos de hidrocarburos en zonas costeras

The study of the seas is a field of science that is in constant development. At the technological level, in recent years, important advances have been made in the design of platforms and measurement systems for oceanographic variables with significant improvements in their sensitivity, as well as in their capacity for spatial and temporal resolution. Currently, given the high costs of traditional techniques (oceanographic vessels), vehicles such as the ROV (Remotely Operated Vehicle), the ASV (Autonomous Surface Vehicle), the AUV (Autonomous Underwater Vehicle) and the AUV Glider are being used instead. From the point of view of the realization of oceanographic studies, the AUV offers more benefits due to its maneuverability and autonomy. An example of this would be the case study of the behavior of marine species based on environmental variables. In this situation, it is essential to carry out a good spatial resolution of multiple parameters, such as salinity, at various depths of the same water column. For the industrial and environmental conservation sectors, there is no specific use of the AUV. However, they can be used in order to obtain bathymetric maps and in the monitoring the specific physical-chemical characteristics of seawater. The motivation of this work is focused on the adaptation of the Guanay II vehicle as a platform for oceanographic measurements, with the ability to navigate in immersion, as well as reducing its possibility of collision with other vehicles or marine structures through its design and implementation of a detection and obstacle avoidance system. This adaptation would allow in the future to use the Guanay II vehicle to perform the detection and monitoring of polluting discharges of hydrocarbons in the sea, as well as monitoring oceanographic data for use in predictive models of the displacement of the spill. The Guanay II is a hybrid vehicle between AUV and ASV, that is, it sails on the surface and performs vertical dives at programmed points. Based on the motivation described, mechanical and electronic modifications have been made to the vehicle, accompanied by a process of study, analysis and mathematical development to obtain a hydrodynamic modeling uncoupled from the vehicle on the vertical plane. A vector propulsion immersion system has been designed and implemented using the lateral thrusters to control the vehicle's inclination during the dive. This system has been simulated in Matlab and implemented in the vehicle, which has allowed testing in the Olympic channel of Castelldefels, the results obtained in these tests have been satisfactory, allowing the vehicle to enter in immersion, remain in immersion during the time defined and then return to surface. On the other hand, in parallel to the design and implementation of this system. A new design has been carried out with the implementation of an obstacle detection and reactive avoidance system incorporated with a fuzzy system, based on a SONAR MK3. This system has been simulated and implemented in the control unit of the vehicle. This system has allowed multiple field tests, which were performed at the Olympic Castelldefels canal. The results obtained in these tests have been satisfactory, achieving in all cases the avoidance of the obstacles present in the navigation environment.El estudio de los mares es un campo de la ciencia que se encuentra en constante desarrollo. A nivel tecnológico, en los últimos años, se han producido importantes avances en el diseño de plataformas y sistemas de medición de variables oceanográficas con importantes mejoras en su sensibilidad, así como en su capacidad de resolución espacial y temporal. Actualmente, debido a los altos costos de las técnicas tradicionales (barcos oceanográficos) se ha incrementado el uso de vehículos no tripulados como los ROV (Remotely Operated Vehicle), los ASV (Autonomous Surface Vehicle), los AUV (Autonomous Underwater Vehicle) y los AUV Glider. Desde el punto de vista de la realización de estudios oceanográficos, los AUV ofrecen mayores beneficios por su mayor maniobrabilidad y autonomía. Un ejemplo de este caso es el estudio del comportamiento de las especies marinas en función de variables ambientales. En estos estudios es indispensable la medida con buena resolución espacial de múltiples parámetros, como la salinidad, a diversas profundidades de una misma columna de agua. Para los sectores industriales y de conservación del medio ambiente no hay un uso específico de los AUV. Pueden ser utilizados en la obtención de mapas batimétricos y en la monitorización de las características físico-químicas especificas del agua del mar. La motivación de este trabajo se centra en la adaptación del vehículo Guanay II como plataforma de mediciones oceanográficas, con la capacidad de navegar en inmersión, así como la reducción de la posibilidad de colisión contra otros vehículos o estructuras marinas mediante el diseño e implantación de un sistema de detección y evasión de obstáculos. Esta adaptación permitiría en el futuro utilizar el vehículo Guanay para realizar la detección y seguimiento de vertidos contaminantes de hidrocarburos en el mar, así como la monitorización de datos oceanográficos para su utilización en modelos predictivos del desplazamiento del vertido. El Guanay II es un vehículo híbrido entre AUV y ASV, es decir, navega en superficie y realiza inmersiones verticales en puntos programados. Con base en la motivación descrita se han realizado modificaciones mecánicas y electrónicas en el vehículo, acompañadas de un proceso de estudio, análisis y de desarrollo matemático para obtener un modelado hidrodinámico desacoplado del vehículo sobre el plano vertical. Se ha diseñado e implementado un sistema de inmersión por propulsión vectorial utilizando los propulsores laterales para controlar la inclinación del vehículo durante la inmersión. Este sistema ha sido simulado en Matlab e implementado en el vehículo, lo que ha permitido probarlo en el canal olímpico de Castelldefels, Los resultados obtenidos en estas pruebas han sido satisfactorios, permitiendo que el vehículo entre en inmersión, se mantenga en inmersión durante el tiempo definido y posteriormente vuelva a superficie. Por otra parte, en paralelo al diseño e implementación de este sistema, se ha llevado a cabo el diseño e implementación de un sistema de detección y evasión de obstáculos de arquitectura reactiva implementado bajo un sistema fuzzy, basado en un sensor SONAR MK3. Este sistema ha sido simulado e implementado en la unidad de control del vehículo. Esta implementación ha permitido realizar múltiples pruebas de campo, las cuales se realizaron en el canal olímpico de Castelldefels. Los resultados obtenidos en estas pruebas han sido satisfactorios, logrando en todos casos la evasión de los obstáculos presentes en el entorno de navegación

Obstacle detection algorithm of low computational cost for Guanay II AUV

Obstacle detection is one of the most important stages in the obstacle avoidance system. This work is focused to explain the operation of a designed and implemented for the overall detection of objects with low computational cost strategy. This strategy of low computational cost is based on performing a spatial segmentation of the information obtained by the SONAR and determine the minimum distance between the SONAR (AUV) and the obstacle.Postprint (published version

Design of obstacle detection and avoidance system for GUANAY II AUV

Postprint (published version

Design a vectorial propulsion system for Guanay II AUV

The autonomous underwater vehicle(AUV) Guanay II was designed to navigate on the surface of the sea, and to realize a vertical immersion in specific points. This vehicle has three thrusters located on stern, oriented to provide propulsion and yaw control on the horizontal plane. On the other hand, the immersion system used in the Guanay II is based in the change of the buoyancy of the vehicle, by using a piston system. Therefore, the vehicle does not have the ability to navigate in immersion, due to its design, which the inclination of the vehicle (pitch angle) cannot be controlled. In this work, we show the design a vector propulsion system for the vehicle Guanay II, which will allow to control the pitch of the AUV in immersion. For this purpose, we have provided to the two laterals thruster the possibility of varying their propulsion angle on the vertical plane, using two servomotors. Next, we will show the design and the results obtained.Postprint (published version

Design of the obstacle detection system with the SONAR MK3 on Guanay II AUV

Autonomous underwater vehicles (AUV) perform inspection missions and intervention in known and unknown environments, where it is necessary to ensure their safety. The AUV must have the ability to detect and avoid obstacles in the path of navigation. This article, an obstacle detection system for experimental Guanay II AUV is proposed, using a mechanical scanning SONAR Tritech Micron MK3. Since Guanay II operates autonomously, we have designed software that allows adjustment and control of the parameters of SONAR, and the acquisition and processing of the signals obtained. Experimental tests at sea have allowed to verify the correct operation of software designed, as well as, experimental tests in a controlled environment have allowed to determine the optimal values of the basic parameters of SONAR.Postprint (published version

Obstacle detection algorithm of low computational cost for Guanay II AUV

Obstacle detection is one of the most important stages in the obstacle avoidance system. This work is focused to explain the operation of a designed and implemented for the overall detection of objects with low computational cost strategy. This strategy of low computational cost is based on performing a spatial segmentation of the information obtained by the SONAR and determine the minimum distance between the SONAR (AUV) and the obstacle

Obstacle detection algorithm of low computational cost for Guanay II AUV

Obstacle detection is one of the most important stages in the obstacle avoidance system. This work is focused to explain the operation of a designed and implemented for the overall detection of objects with low computational cost strategy. This strategy of low computational cost is based on performing a spatial segmentation of the information obtained by the SONAR and determine the minimum distance between the SONAR (AUV) and the obstacle

Design a vectorial propulsion system for Guanay II AUV

The autonomous underwater vehicle(AUV) Guanay II was designed to navigate on the surface of the sea, and to realize a vertical immersion in specific points. This vehicle has three thrusters located on stern, oriented to provide propulsion and yaw control on the horizontal plane. On the other hand, the immersion system used in the Guanay II is based in the change of the buoyancy of the vehicle, by using a piston system. Therefore, the vehicle does not have the ability to navigate in immersion, due to its design, which the inclination of the vehicle (pitch angle) cannot be controlled. In this work, we show the design a vector propulsion system for the vehicle Guanay II, which will allow to control the pitch of the AUV in immersion. For this purpose, we have provided to the two laterals thruster the possibility of varying their propulsion angle on the vertical plane, using two servomotors. Next, we will show the design and the results obtained

Obstacle detection and avoidance system for Guanay II AUV

Postprint (published version