1,394 research outputs found

    Laser-Based Detection and Tracking of Moving Obstacles to Improve Perception of Unmanned Ground Vehicles

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    El objetivo de esta tesis es desarrollar un sistema que mejore la etapa de percepción de vehículos terrestres no tripulados (UGVs) heterogéneos, consiguiendo con ello una navegación robusta en términos de seguridad y ahorro energético en diferentes entornos reales, tanto interiores como exteriores. La percepción debe tratar con obstáculos estáticos y dinámicos empleando sensores heterogéneos, tales como, odometría, sensor de distancia láser (LIDAR), unidad de medida inercial (IMU) y sistema de posicionamiento global (GPS), para obtener la información del entorno con la precisión más alta, permitiendo mejorar las etapas de planificación y evitación de obstáculos. Para conseguir este objetivo, se propone una etapa de mapeado de obstáculos dinámicos (DOMap) que contiene la información de los obstáculos estáticos y dinámicos. La propuesta se basa en una extensión del filtro de ocupación bayesiana (BOF) incluyendo velocidades no discretizadas. La detección de velocidades se obtiene con Flujo Óptico sobre una rejilla de medidas LIDAR discretizadas. Además, se gestionan las oclusiones entre obstáculos y se añade una etapa de seguimiento multi-hipótesis, mejorando la robustez de la propuesta (iDOMap). La propuesta ha sido probada en entornos simulados y reales con diferentes plataformas robóticas, incluyendo plataformas comerciales y la plataforma (PROPINA) desarrollada en esta tesis para mejorar la colaboración entre equipos de humanos y robots dentro del proyecto ABSYNTHE. Finalmente, se han propuesto métodos para calibrar la posición del LIDAR y mejorar la odometría con una IMU

    Proceedings of the 20th SIRWEC conference, Druskininkai, Lithuania (14-16th June 2022)

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    SIRWEC (The Standing International Road Weather Commission) exists to encourage meteorologists, weather forecasters, highway engineers, road masters and others, who are interested in road weather problems, to exchange ideas to make our roads safer to drive on in all weather conditions. Every two years SIRWEC conference is being organized to gather all of the road weather enthusiasts and encourage them to share new scientific discoveries they have accomplished, new products or technologies they have made or any other topic in road weather field

    Design og styring av smarte robotsystemer for applikasjoner innen biovitenskap: biologisk prøvetaking og jordbærhøsting

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    This thesis aims to contribute knowledge to support fully automation in life-science applications, which includes design, development, control and integration of robotic systems for sample preparation and strawberry harvesting, and is divided into two parts. Part I shows the development of robotic systems for the preparation of fungal samples for Fourier transform infrared (FTIR) spectroscopy. The first step in this part developed a fully automated robot for homogenization of fungal samples using ultrasonication. The platform was constructed with a modified inexpensive 3D printer, equipped with a camera to distinguish sample wells and blank wells. Machine vision was also used to quantify the fungi homogenization process using model fitting, suggesting that homogeneity level to ultrasonication time can be well fitted with exponential decay equations. Moreover, a feedback control strategy was proposed that used the standard deviation of local homogeneity values to determine the ultrasonication termination time. The second step extended the first step to develop a fully automated robot for the whole process preparation of fungal samples for FTIR spectroscopy by adding a newly designed centrifuge and liquid-handling module for sample washing, concentration and spotting. The new system used machine vision with deep learning to identify the labware settings, which frees the users from inputting the labware information manually. Part II of the thesis deals with robotic strawberry harvesting. This part can be further divided into three stages. i) The first stage designed a novel cable-driven gripper with sensing capabilities, which has high tolerance to positional errors and can reduce picking time with a storage container. The gripper uses fingers to form a closed space that can open to capture a fruit and close to push the stem to the cutting area. Equipped with internal sensors, the gripper is able to control a robotic arm to correct for positional errors introduced by the vision system, improving the robustness. The gripper and a detection method based on color thresholding were integrated into a complete system for strawberry harvesting. ii) The second stage introduced the improvements and updates to the first stage where the main focus was to address the challenges in unstructured environment by introducing a light-adaptive color thresholding method for vision and a novel obstacle-separation algorithm for manipulation. At this stage, the new fully integrated strawberry-harvesting system with dual-manipulator was capable of picking strawberries continuously in polytunnels. The main scientific contribution of this stage is the novel obstacle-separation path-planning algorithm, which is fundamentally different from traditional path planning where obstacles are typically avoided. The algorithm uses the gripper to push aside surrounding obstacles from an entrance, thus clearing the way for it to swallow the target strawberry. Improvements were also made to the gripper, the arm, and the control. iii) The third stage improved the obstacle-separation method by introducing a zig-zag push for both horizontal and upward directions and a novel dragging operation to separate upper obstacles from the target. The zig-zag push can help the gripper capture a target since the generated shaking motion can break the static contact force between the target and obstacles. The dragging operation is able to address the issue of mis-capturing obstacles located above the target, in which the gripper drags the target to a place with fewer obstacles and then pushes back to move the obstacles aside for further detachment. The separation paths are determined by the number and distribution of obstacles based on the downsampled point cloud in the region of interest.Denne avhandlingen tar sikte på å bidra med kunnskap om automatisering og robotisering av applikasjoner innen livsvitenskap. Avhandlingen er todelt, og tar for seg design, utvikling, styring og integrering av robotsystemer for prøvetaking og jordbærhøsting. Del I omhandler utvikling av robotsystemer til bruk under forberedelse av sopprøver for Fourier-transform infrarød (FTIR) spektroskopi. I første stadium av denne delen ble det utviklet en helautomatisert robot for homogenisering av sopprøver ved bruk av ultralyd-sonikering. Plattformen ble konstruert ved å modifisere en billig 3D-printer og utstyre den med et kamera for å kunne skille prøvebrønner fra kontrollbrønner. Maskinsyn ble også tatt i bruk for å estimere soppens homogeniseringsprosess ved hjelp av matematisk modellering, noe som viste at homogenitetsnivået faller eksponensielt med tiden. Videre ble det foreslått en strategi for regulering i lukker sløyfe som brukte standardavviket for lokale homogenitetsverdier til å bestemme avslutningstidspunkt for sonikeringen. I neste stadium ble den første plattformen videreutviklet til en helautomatisert robot for hele prosessen som forbereder prøver av sopprøver for FTIR-spektroskopi. Dette ble gjort ved å legge til en nyutviklet sentrifuge- og væskehåndteringsmodul for vasking, konsentrering og spotting av prøver. Det nye systemet brukte maskinsyn med dyp læring for å identifisere innstillingene for laboratorieutstyr, noe som gjør at brukerne slipper å registrere innstillingene manuelt.Norwegian University of Life SciencespublishedVersio

    Sailing:Cognition, Action, Communication

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    How do humans perceive and think about space, and how can this be represented adequately? For everyday activities such as locating objects or places, route planning, and the like, many insights have been gained over the past few decades, feeding into theories of spatial cognition and frameworks for spatial information science. In this paper, we explore sailing as a more specialized domain that has not yet been considered in this way, but has a lot to offer precisely because of its peculiarities. Sailing involves ways of thinking about space that are not normally required (or even acquired) in everyday life. Movement in this domain is based on a combination of external forces and internal (human) intentions that impose various kinds of directionality, affecting local action as well as global planning. Sailing terminology is spatial to a high extent, and involves a range of concepts that have received little attention in the spatial cognition community. We explore the area by focusing on the core features of cognition, action, and communication, and suggest a range of promising future areas of research in this domain as a showcase of the fascinating flexibility of human spatial cognition

    Contribution to design a communication framework for vehicular ad hoc networks in urban scenarios

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    The constant mobility of people, the growing need to be always connected, the large number of vehicles that nowadays can be found in the roads and the advances in technology make Vehicular Ad hoc Networks (VANETs) be a major area of research. Vehicular Ad hoc Networks are a special type of wireless Mobile Ad hoc Networks (MANETs), which allow a group of mobile nodes configure a temporary network and maintain it without the need of a fixed infrastructure. A vehicular network presents some specific characteristics, as the very high speed of nodes. Due to this high speed the topology changes are frequent and the communication links may last only a few seconds. Smart cities are now a reality and have a direct relationship with vehicular networks. With the help of existing infrastructure such as traffic lights, we propose a scheme to update and analyse traffic density and a warning system to spread alert messages. With this, traffic lights assist vehicular networks to take proper decisions. This would ensure less congested streets. It would also be possible that the routing protocol forwards data packets to vehicles on streets with enough neighbours to increase the possibility of delivering the packets to destination. Sharing updated, reliable and real-time information, about traffic conditions, weather or security alerts, increases the need of algorithms for the dissemination of information that take into account the main beneffits and constraints of these networks. For all this, routing protocols for vehicular networks have the difficult task to select and establish transmission links to send the data packets from source to destination through multiple nodes using intermediate vehicles efficiently. The main objective of this thesis is to provide improvements in the communication framework for vehicular networks to improve decisions to select next hops in the moment to send information, in this way improving the exchange of information to provide suitable communication to minimize accidents, reduce congestion, optimize resources for emergencies, etc. Also, we include intelligence to vehicles at the moment to take routing decisions. Making them map-aware, being conscious of the presence of buildings and other obstacles in urban environments. Furthermore, our proposal considers the decision to store packets for a maximum time until finding other neighbouring nodes to forward the packets before discarding them. For this, we propose a protocol that considers multiple metrics that we call MMMR (A Multimetric, Map-Aware Routing Protocol ). MMMR is a protocol based on geographical knowledge of the environment and vehicle location. The metrics considered are the distance, the density of vehicles in transmission range, the available bandwidth and the future trajectory of the neighbouring nodes. This allows us to have a complete view of the vehicular scenario to anticipate the driver about possible changes that may occur. Thus, a node can select a node among all its neighbours, which is the best option to increase the likelihood of successful packet delivery, minimizing time and offering a level of quality and service. In the same way, being aware of the increase of information in wireless environments, we analyse the possibility of offering anonymity services. We include a mechanism of anonymity in routing protocols based on the Crowd algorithm, which uses the idea of hiding the original source of a packet. This allowed us to add some level of anonymity on VANET routing protocols. The analytical modeling of the available bandwidth between nodes in a VANET, the use of city infrastructure in a smart way, the forwarding selection in data routing byvehicles and the provision of anonymity in communications, are issues that have been addressed in this PhD thesis. In our research work we provide contributions to improve the communication framework for Vehicular Ad hoc Networks obtaining benefits toenhance the everyday of the population.La movilidad constante de las personas y la creciente necesidad de estar conectados en todo momento ha hecho de las redes vehiculares un área cuyo interés ha ido en aumento. La gran cantidad de vehículos que hay en la actualidad, y los avances tecnológicos han hecho de las redes vehiculares (VANETS, Vehicular Ad hoc Networks) un gran campo de investigación. Las redes vehiculares son un tipo especial de redes móviles ad hoc inalámbricas, las cuales, al igual que las redes MANET (Mobile Ad hoc Networks), permiten a un grupo de nodos móviles tanto configurar como mantener una red temporal por si mismos sin la necesidad de una infraestructura fija. Las redes vehiculares presentan algunas características muy representativas, por ejemplo, la alta velocidad que pueden alcanzar los nodos, en este caso vehículos. Debido a esta alta velocidad la topología cambia frecuentemente y la duración de los enlaces de comunicación puede ser de unos pocos segundos. Estas redes tienen una amplia área de aplicación, pudiendo tener comunicación entre los mismos nodos (V2V) o entre los vehículos y una infraestructura fija (V2I). Uno de los principales desafíos existentes en las VANET es la seguridad vial donde el gobierno y fabricantes de automóviles han centrado principalmente sus esfuerzos. Gracias a la rápida evolución de las tecnologías de comunicación inalámbrica los investigadores han logrado introducir las redes vehiculares dentro de las comunicaciones diarias permitiendo una amplia variedad de servicios para ofrecer. Las ciudades inteligentes son ahora una realidad y tienen una relación directa con las redes vehiculares. Con la ayuda de la infraestructura existente, como semáforos, se propone un sistema de análisis de densidad de tráfico y mensajes de alerta. Con esto, los semáforos ayudan a la red vehicular en la toma de decisiones. Así se logrará disponer de calles menos congestionadas para hacer una circulación más fluida (lo cual disminuye la contaminación). Además, sería posible que el protocolo de encaminamiento de datos elija vehículos en calles con suficientes vecinos para incrementar la posibilidad de entregar los paquetes al destino (minimizando pérdidas de información). El compartir información actualizada, confiable y en tiempo real sobre el estado del tráfico, clima o alertas de seguridad, aumenta la necesidad de algoritmos de difusión de la información que consideren los principales beneficios y restricciones de estas redes. Así mismo, considerar servicios críticos que necesiten un nivel de calidad y servicio es otro desafío importante. Por todo esto, un protocolo de encaminamiento para este tipo de redes tiene la difícil tarea de seleccionar y establecer enlaces de transmisión para enviar los datos desde el origen hacia el destino vía múltiples nodos utilizando vehículos intermedios de una manera eficiente. El principal objetivo de esta tesis es ofrecer mejoras en los sistemas de comunicación vehicular que mejoren la toma de decisiones en el momento de realizar el envío de la información, con lo cual se mejora el intercambio de información para poder ofrecer comunicación oportuna que minimice accidentes, reduzca atascos, optimice los recursos destinados a emergencias, etc. Así mismo, incluimos más inteligencia a los coches en el momento de tomar decisiones de encaminamiento de paquetes. Haciéndolos conscientes de la presencia de edificios y otros obstáculos en los entornos urbanos. Así como tomar la decisión de guardar paquetes durante un tiempo máximo de modo que se encuentre otros nodos vecinos para encaminar paquetes de información antes de descartarlo. Para esto, proponemos un protocolo basado en múltiples métricas (MMMR, A Multimetric, Map-aware Routing Protocol ) que es un protocolo geográfio basado en el conocimiento del entorno y localización de los vehículos. Las métricas consideradas son la distancia, la densidad de vehículos en el área de transmisión, el ancho de banda disponible y la trayectoria futura de los nodos vecinos. Esto nos permite tener una visión completa del escenario vehicular y anticiparnos a los posibles cambios que puedan suceder. Así, un nodo podrá seleccionar aquel nodo entre todos sus vecinos posibles que sea la mejor opción para incrementar la posibilidad de entrega exitosa de paquetes, minimizando tiempos y ofreciendo un cierto nivel de calidad y servicio. De la misma manera, conscientes del incremento de información que circula por medios inalámbricos, se analizó la posibilidad de servicios de anonimato. Incluimos pues un mecanismo de anonimato en protocolos de encaminamiento basado en el algoritmo Crowd, que se basa en la idea de ocultar la fuente original de un paquete. Esto nos permitió añadir cierto nivel de anonimato que pueden ofrecer los protocolos de encaminamiento. El modelado analítico del ancho de banda disponible entre nodos de una VANET, el uso de la infraestructura de la ciudad de una manera inteligente, la adecuada toma de decisiones de encaminamiento de datos por parte de los vehículos y la disposición de anonimato en las comunicaciones, son problemas que han sido abordados en este trabajo de tesis doctoral que ofrece contribuciones a la mejora de las comunicaciones en redes vehiculares en entornos urbanos aportando beneficios en el desarrollo de la vida diaria de la población

    Rural expressway intersection safety treatment evaluations

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    A rural expressway is a high-speed, multi-lane, divided highway with partial access control which may consist of both at-grade intersections and grade separated interchanges. Many State Transportation Agencies (STAs) are converting rural two-lane undivided highways into expressways for improved safety and mobility; however, collisions at two-way stop-controlled (TWSC) intersections (particularly far-side right-angle crashes) on rural expressways are reducing the safety benefits that should be achieved through conversion. When the safety performance of these intersections begins to deteriorate, the improvement path typically begins with the application of several signing, marking, or lighting improvements, followed by signalization, and ultimately grade separation. Because signals hamper the mobility expressways are meant to provide and because interchanges are not economically feasible at all problematic intersections, there is a need for more design options at TWSC rural expressway intersections. Some STAs have experimented with innovative rural expressway intersection safety treatments to avoid signalization and grade separation; however, little is known about the safety effects of these designs. Therefore, the objective of this research was to document their experience with these treatments and to conduct nayve before-after safety evaluations where possible. The ten case studies included within this thesis investigate J-turn intersections, offset T-intersections, jughandle intersections, Intersection Decision Support (IDS) technology, static roadside markers, left-turn median acceleration lanes (MALs), offset right-turn lanes, offset left-turn lanes, enhanced intersection guide signing, and dynamic advance intersection warning systems. These case studies help to begin to understand the safety improvement potential of these countermeasures and start to set the stage for the development of a richer set of design options at TWSC rural expressway intersections

    Fuzzy Cognitive Maps and Neutrosophic Cognitive Maps

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    As extension of Fuzzy Cognitive Maps are now introduced the Neutrosophic Cognitive Map

    Advancing public health in the context of natural hazards : normalising preparedness within a framework of adapted protection motivation theory

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    This research sought to discover and recommend proactive strategies to strengthen and improve human safety and well-being in a changing climate of natural hazards. This thesis documents the rationale, process and outcomes of that research. People’s ability to navigate their daily lives within an environment of worsening natural hazards is an adaptive public health and safety priority - given the predicted global increase in frequency and severity of extreme weather events. There is an urgent need to strengthen and normalise people’s preparedness behaviour, and to connect it with an unequivocal understanding of the benefits of such changes. Enhancing people's adaptive responses will help to avoid, or at least minimise, associated human trauma and tragedy. That is the aim of this research. Achieving positive, adaptive change requires proactive medium to longer term public policy planning and implementation of strategies leading to considered, appropriate response choices and desired protective behaviour as social norms. Demands upon individuals, families, communities and workplaces are high in the complexity of 21st century life: adapting to narrow the bushfire (or other natural hazard) awareness-preparedness gap – to become fire-fit – requires a re-ordering of priorities so that fire-fitness becomes a societal-wide, integrated routine – as routine as buying groceries or fuelling a car. This predominantly pragmatic qualitative research used the socio-cognitive Protection Motivation Theory (described by Rogers in 1975) in the context of bushfire natural hazards with the ultimate aim of reducing human morbidity and mortality, and concurrently promoting positive physical and psychological capacity. The study considered data across and within two demographic groups – emergency responders and the owners of any kind and any number of animals. It sought to 1. determine and discover how casualties to life, property and the environment, including the physical and psychological health of people, their microclimates and livelihoods, can be reduced and minimised while building a culture of preparedness as an integral part of daily life, and 2. help negate wider perceptions of preparedness as a difficult, time-consuming task which although on nearly everyone’s ‘to do’ list is frequently not prioritised. The major qualitative phase (phase 1) was followed by a minor quantitative phase (phase 2) in the form of a pilot survey (discussed in Chapter 7) that investigated farmers’ bushfire experiences and management strategies. The pilot survey was conducted with a view to determining topics requiring further research, as well as identifying knowledge and learning translatable to novice landowners. This thesis is presented as a series of six papers – four published (P1-P4), two submitted (SP1, SP2). Each paper addresses particular research questions, noted in the box at the beginning of each chapter, and each published paper is followed by a connecting narrative designed to convey the momentum, flow and logic of the research progression. The order of the papers presented in the thesis follows the chronology of the research. Paper 1 critically explores the literature and investigates Protection Motivation Theory (PMT) as a framework. Paper 2 provides an overview of the qualitative data and identifies the focus for the next stage of analysis. Paper 3 discusses public policy and leads in to Paper 4 which proposes a number of innovative and practical strategies to help improve fire-fitness for individuals and across communities. The following two papers supplement and complement the four published papers. SP1 contains more detail concerning public policy initiatives. SP2 is essentially P1 in practice and demonstrates how PMT can be usefully applied to achieve the aim of the research - to reduce human morbidity and mortality in natural hazard events. Thus, the reader is encouraged to read SP1 following P3, and SP2 following P4. Readers’ attention is drawn particularly to the Results, Interpretative Analysis and Discussion sections in SP1 and SP2, where additional information on policy and how PMT was expanded and applied may be found. Journal selection for the published papers was actively – and flexibly - considered from the beginning of the project with the selection of suitable journals narrowing as the focus of the research itself became more specific. Table 1, Journal selection and chronology of publication, details this process. The research results indicate desired outcomes are indeed achievable by engaging a bold, innovative willingness to move beyond standard conservatism in the sector, and demonstrating a commitment to trial and evaluate recommendations. The wellbeing and safety of people in natural hazards is increasingly a public health issue. This thesis proposes proactive initiatives that affirmatively and assertively respond to meeting the parallel escalation of the inherent danger of natural hazards in a changing climate without alienating public sentiment. It also identifies the need for further research to fill a gaping omission in the literature regarding cropland fires - with respect to crop types and placement, how different crops ‘carry’ a fire, and if firebreaks can be better utilised as a fire management tool. A summary of the strategies developed from the results of this research is presented in Table 4, Strategies to help achieve fire-fitness. These are described in more detail in papers P3, P4, SP1 and SP2. In reconstructing the ‘costs’ and ‘rewards’ described in an expanded Protection Motivation Theory to favour an overall net gain, and by providing ways to establish fire-fitness as a desirable and attainable social norm, this research makes a practical and timely contribution to future public policy decision-making in the global ‘new reality’ of natural hazards

    Statistical modelling of algorithms for signal processing in systems based on environment perception

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    One cornerstone for realising automated driving systems is an appropriate handling of uncertainties in the environment perception and situation interpretation. Uncertainties arise due to noisy sensor measurements or the unknown future evolution of a traffic situation. This work contributes to the understanding of these uncertainties by modelling and propagating them with parametric probability distributions
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