The problem addressed in this thesis is the detection, localisation and tracking of human workers from mobile industrial machinery using a customised vision system developed at Örebro University. Coined the RefleX Vision System, its hardware configuration and computer vision algorithms were specifically designed for real-world industrial scenarios where workers are required to wear protective high-visibility garments with retro-reflective markers. The demand for robust industry-purpose human sensing methods originates from the fact that many industrial environments represent work spaces that are shared between humans and mobile machinery. Typical examples of such environments include construction sites, surface and underground mines, storage yards and warehouses. Here, accidents involving mobile equipment and human workers frequently result in serious injuries and fatalities. Robust sensor-based detection of humans in the surrounding of mobile equipment is therefore an active research topic and represents a crucial requirement for safe vehicle operation and accident prevention in increasingly automated production sites. Addressing the described safety issue, this thesis presents a collection of papers which introduce, analyse and evaluate a novel vision-based method for detecting humans equipped with protective high-visibility garments in the neighbourhood of manned or unmanned industrial vehicles. The thesis provides a comprehensive discussion of the numerous aspects regarding the design of the hardware and the computer vision algorithms that constitute the vision system. An active nearinfrared camera setup that is customised for the robust perception of retroreflective markers builds the basis for the sensing method. Using its specific input, a set of computer vision and machine learning algorithms then perform extraction, analysis, classification and localisation of the observed reflective patterns, and eventually detection and tracking of workers with protective garments. Multiple real-world challenges, which existing methods frequently struggle to cope with, are discussed throughout the thesis, including varying ambient lighting conditions and human body pose variation. The presented work has been carried out with a strong focus on industrial applicability, and therefore includes an extensive experimental evaluation in a number of different real-world indoor and outdoor work environments.

On regroupe sous l’expression navigation autonome l’ensemble des méthodes visantà automatiser les déplacements d’un robot mobile. Les travaux présentés seconcentrent sur la problématique de la localisation en milieu extérieur, urbain etpériurbain, et approchent la problématique de la localisation visuelle soumise à lafois à un changement de capteurs (géométrie et modalité) ainsi qu’aux changementsde l’environnement à long terme, contraintes combinées encore très peu étudiéesdans l’état de l’art. Les recherches menées dans le cadre de cette thèse ont porté surl’utilisation exclusive de capteurs de vision. La contribution majeure de cette thèseporte sur la phase de description et compression des données issues des images sousla forme d’un histogramme de mots visuels que nous avons nommée PHROG (PluralHistograms of Restricted Oriented Gradients). Les expériences menées ont été réaliséessur plusieurs bases d’images avec différentes modalités visibles et infrarouges. Lesrésultats obtenus démontrent une amélioration des performances de reconnaissance descènes comparés aux méthodes de l’état de l’art. Par la suite, nous nous intéresseronsà la nature séquentielle des images acquises dans un contexte de navigation afin defiltrer et supprimer des estimations de localisation aberrantes. Les concepts d’un cadreprobabiliste Bayésien permettent deux applications de filtrage probabiliste appliquéesà notre problématique : une première solution définit un modèle de déplacementsimple du robot avec un filtre d’histogrammes et la deuxième met en place un modèleplus évolué faisant appel à l’odométrie visuelle au sein d’un filtre particulaire.123 / Autonomous navigation field gathers the set of algorithms which automate the moves of a mobile robot. The case study of this thesis focuses on the outdoor localisation issue with additionnal constraints : the use of visual sensors only with variable specifications (geometry, modality, etc) and long-term apparence changes of the surrounding environment. Both types of constraints are still rarely studied in the state of the art. Our main contribution concerns the description and compression steps of the data extracted from images. We developped a method called PHROG which represents data as a visual-words histogram. Obtained results on several images datasets show an improvment of the scenes recognition performance compared to methods from the state of the art. In a context of navigation, acquired images are sequential such that we can envision a filtering method to avoid faulty localisation estimation. Two probabilistic filtering approaches are proposed : a first one defines a simple movement model with a histograms filter and a second one sets up a more complex model using visual odometry and a particules filter.