78 research outputs found

    Lorentz covariance `almost' implies electromagnetism and more?

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    Beginning from two simple assumptions, i) the speed of light is a universal constant, or its equivalent, the spacetime intervals are Lorentz invariant, and ii) there are mutually interacting particles, with a covariant `source-field' equation, one arrives at a class of field equations of which the standard electromagnetism (EM) and electrodynamics (ED) are special cases. The formalism, depending on how one formulates the source-field equation, allows one to speculate magnetic monopoles, massive photons, non-linear EM's, and more.Comment: To be published in European Journal of Physics. Dedicated to the international year of light. arXiv admin note: substantial text overlap with arXiv:1301.469

    Cross-Domain Car Detection Using Unsupervised Image-to-Image Translation: From Day to Night

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    Deep learning techniques have enabled the emergence of state-of-the-art models to address object detection tasks. However, these techniques are data-driven, delegating the accuracy to the training dataset which must resemble the images in the target task. The acquisition of a dataset involves annotating images, an arduous and expensive process, generally requiring time and manual effort. Thus, a challenging scenario arises when the target domain of application has no annotated dataset available, making tasks in such situation to lean on a training dataset of a different domain. Sharing this issue, object detection is a vital task for autonomous vehicles where the large amount of driving scenarios yields several domains of application requiring annotated data for the training process. In this work, a method for training a car detection system with annotated data from a source domain (day images) without requiring the image annotations of the target domain (night images) is presented. For that, a model based on Generative Adversarial Networks (GANs) is explored to enable the generation of an artificial dataset with its respective annotations. The artificial dataset (fake dataset) is created translating images from day-time domain to night-time domain. The fake dataset, which comprises annotated images of only the target domain (night images), is then used to train the car detector model. Experimental results showed that the proposed method achieved significant and consistent improvements, including the increasing by more than 10% of the detection performance when compared to the training with only the available annotated data (i.e., day images).Comment: 8 pages, 8 figures, https://github.com/viniciusarruda/cross-domain-car-detection and accepted at IJCNN 201

    Search-based Test Generation for Automated Driving Systems: From Perception to Control Logic

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    abstract: Automated driving systems are in an intensive research and development stage, and the companies developing these systems are targeting to deploy them on public roads in a very near future. Guaranteeing safe operation of these systems is crucial as they are planned to carry passengers and share the road with other vehicles and pedestrians. Yet, there is no agreed-upon approach on how and in what detail those systems should be tested. Different organizations have different testing approaches, and one common approach is to combine simulation-based testing with real-world driving. One of the expectations from fully-automated vehicles is never to cause an accident. However, an automated vehicle may not be able to avoid all collisions, e.g., the collisions caused by other road occupants. Hence, it is important for the system designers to understand the boundary case scenarios where an autonomous vehicle can no longer avoid a collision. Besides safety, there are other expectations from automated vehicles such as comfortable driving and minimal fuel consumption. All safety and functional expectations from an automated driving system should be captured with a set of system requirements. It is challenging to create requirements that are unambiguous and usable for the design, testing, and evaluation of automated driving systems. Another challenge is to define useful metrics for assessing the testing quality because in general, it is impossible to test every possible scenario. The goal of this dissertation is to formalize the theory for testing automated vehicles. Various methods for automatic test generation for automated-driving systems in simulation environments are presented and compared. The contributions presented in this dissertation include (i) new metrics that can be used to discover the boundary cases between safe and unsafe driving conditions, (ii) a new approach that combines combinatorial testing and optimization-guided test generation methods, (iii) approaches that utilize global optimization methods and random exploration to generate critical vehicle and pedestrian trajectories for testing purposes, (iv) a publicly-available simulation-based automated vehicle testing framework that enables application of the existing testing approaches in the literature, including the new approaches presented in this dissertation.Dissertation/ThesisDoctoral Dissertation Computer Engineering 201

    A Voice and Pointing Gesture Interaction System for Supporting Human Spontaneous Decisions in Autonomous Cars

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    Autonomous cars are expected to improve road safety, traffic and mobility. It is projected that in the next 20-30 years fully autonomous vehicles will be on the market. The advancement on the research and development of this technology will allow the disengagement of humans from the driving task, which will be responsibility of the vehicle intelligence. In this scenario new vehicle interior designs are proposed, enabling more flexible human vehicle interactions inside them. In addition, as some important stakeholders propose, control elements such as the steering wheel and accelerator and brake pedals may not be needed any longer. However, this user control disengagement is one of the main issues related with the user acceptance of this technology. Users do not seem to be comfortable with the idea of giving all the decision power to the vehicle. In addition, there can be location awareness situations where the user makes a spontaneous decision and requires some type of vehicle control. Such is the case of stopping at a particular point of interest or taking a detour in the pre-calculated autonomous route of the car. Vehicle manufacturers\u27 maintain the steering wheel as a control element, allowing the driver to take over the vehicle if needed or wanted. This causes a constraint in the previously mentioned human vehicle interaction flexibility. Thus, there is an unsolved dilemma between providing users enough control over the autonomous vehicle and route so they can make spontaneous decision, and interaction flexibility inside the car. This dissertation proposes the use of a voice and pointing gesture human vehicle interaction system to solve this dilemma. Voice and pointing gestures have been identified as natural interaction techniques to guide and command mobile robots, potentially providing the needed user control over the car. On the other hand, they can be executed anywhere inside the vehicle, enabling interaction flexibility. The objective of this dissertation is to provide a strategy to support this system. For this, a method based on pointing rays intersections for the computation of the point of interest (POI) that the user is pointing to is developed. Simulation results show that this POI computation method outperforms the traditional ray-casting based by 76.5% in cluttered environments and 36.25% in combined cluttered and non-cluttered scenarios. The whole system is developed and demonstrated using a robotics simulator framework. The simulations show how voice and pointing commands performed by the user update the predefined autonomous path, based on the recognized command semantics. In addition, a dialog feedback strategy is proposed to solve conflicting situations such as ambiguity in the POI identification. This additional step is able to solve all the previously mentioned POI computation inaccuracies. In addition, it allows the user to confirm, correct or reject the performed commands in case the system misunderstands them

    HIGH QUALITY HUMAN 3D BODY MODELING, TRACKING AND APPLICATION

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    Geometric reconstruction of dynamic objects is a fundamental task of computer vision and graphics, and modeling human body of high fidelity is considered to be a core of this problem. Traditional human shape and motion capture techniques require an array of surrounding cameras or subjects wear reflective markers, resulting in a limitation of working space and portability. In this dissertation, a complete process is designed from geometric modeling detailed 3D human full body and capturing shape dynamics over time using a flexible setup to guiding clothes/person re-targeting with such data-driven models. As the mechanical movement of human body can be considered as an articulate motion, which is easy to guide the skin animation but has difficulties in the reverse process to find parameters from images without manual intervention, we present a novel parametric model, GMM-BlendSCAPE, jointly taking both linear skinning model and the prior art of BlendSCAPE (Blend Shape Completion and Animation for PEople) into consideration and develop a Gaussian Mixture Model (GMM) to infer both body shape and pose from incomplete observations. We show the increased accuracy of joints and skin surface estimation using our model compared to the skeleton based motion tracking. To model the detailed body, we start with capturing high-quality partial 3D scans by using a single-view commercial depth camera. Based on GMM-BlendSCAPE, we can then reconstruct multiple complete static models of large pose difference via our novel non-rigid registration algorithm. With vertex correspondences established, these models can be further converted into a personalized drivable template and used for robust pose tracking in a similar GMM framework. Moreover, we design a general purpose real-time non-rigid deformation algorithm to accelerate this registration. Last but not least, we demonstrate a novel virtual clothes try-on application based on our personalized model utilizing both image and depth cues to synthesize and re-target clothes for single-view videos of different people

    A Systematic Survey of ML Datasets for Prime CV Research Areas-Media and Metadata

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    The ever-growing capabilities of computers have enabled pursuing Computer Vision through Machine Learning (i.e., MLCV). ML tools require large amounts of information to learn from (ML datasets). These are costly to produce but have received reduced attention regarding standardization. This prevents the cooperative production and exploitation of these resources, impedes countless synergies, and hinders ML research. No global view exists of the MLCV dataset tissue. Acquiring it is fundamental to enable standardization. We provide an extensive survey of the evolution and current state of MLCV datasets (1994 to 2019) for a set of specific CV areas as well as a quantitative and qualitative analysis of the results. Data were gathered from online scientific databases (e.g., Google Scholar, CiteSeerX). We reveal the heterogeneous plethora that comprises the MLCV dataset tissue; their continuous growth in volume and complexity; the specificities of the evolution of their media and metadata components regarding a range of aspects; and that MLCV progress requires the construction of a global standardized (structuring, manipulating, and sharing) MLCV "library". Accordingly, we formulate a novel interpretation of this dataset collective as a global tissue of synthetic cognitive visual memories and define the immediately necessary steps to advance its standardization and integration

    LiDAR Domain Adaptation - Automotive 3D Scene Understanding

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    Umgebungswahrnehmung und Szeneverständnis spielen bei autonomen Fahrzeugen eine wesentliche Rolle. Ein Fahrzeug muss sich der Geometrie und Semantik seiner Umgebung bewusst sein, um das Verhalten anderer Verkehrsteilnehmer:innen vorherzusagen und sich selbst im fahrbaren Raum zu lokalisieren, um somit richtig zu navigieren. Heutzutage verwenden praktisch alle modernen Wahrnehmungssysteme für das automatisierte Fahren tiefe neuronale Netze. Um diese zu trainieren, werden enorme Datenmengen mit passenden Annotationen benötigt. Die Beschaffung der Daten ist relativ unaufwendig, da nur ein mit den richtigen Sensoren ausgestattetes Fahrzeug herumfahren muss. Die Erstellung von Annotationen ist jedoch ein sehr zeitaufwändiger und teurer Prozess. Erschwerend kommt hinzu, dass autonome Fahrzeuge praktisch überall (z.B. Europa und Asien, auf dem Land und in der Stadt) und zu jeder Zeit (z.B. Tag und Nacht, Sommer und Winter, Regen und Nebel) eingesetzt werden müssen. Dies erfordert, dass die Daten eine noch größere Anzahl unterschiedlicher Szenarien und Domänen abdecken. Es ist nicht praktikabel, Daten für eine solche Vielzahl von Domänen zu sammeln und zu annotieren. Wenn jedoch nur mit Daten aus einer Domäne trainiert wird, führt dies aufgrund von Unterschieden in den Daten zu einer schlechten Leistung in einer anderen Zieldomäne. Für eine sicherheitskritische Anwendung ist dies nicht akzeptabel. Das Gebiet der sogenannten Domänenanpassung führt Methoden ein, die helfen, diese Domänenlücken ohne die Verwendung von Annotationen aus der Zieldomäne zu schließen und somit auf die Entwicklung skalierbarer Wahrnehmungssysteme hinzuarbeiten. Die Mehrzahl der Arbeiten zur Domänenanpassung konzentriert sich auf die zweidimensionale Kamerawahrnehmung. In autonomen Fahrzeugen ist jedoch das dreidimensionale Verständnis der Szene essentiell, wofür heutzutage häufig LiDAR-Sensoren verwendet werden. Diese Dissertation befasst sich mit der Domänenanpassung für LiDAR-Wahrnehmung unter mehreren Aspekten. Zunächst wird eine Reihe von Techniken vorgestellt, die die Leistung und die Laufzeit von semantischen Segmentierungssystemen verbessern. Die gewonnenen Erkenntnisse werden in das Wahrnehmungsmodell integriert, das in dieser Dissertation verwendet wird, um die Wirksamkeit der vorgeschlagenen Domänenanpassungsansätze zu bewerten. Zweitens werden bestehende Ansätze diskutiert und Forschungslücken durch die Formulierung von offenen Forschungsfragen aufgezeigt. Um einige dieser Fragen zu beantworten, wird in dieser Dissertation eine neuartige quantitative Metrik vorgestellt. Diese Metrik erlaubt es, den Realismus von LiDAR-Daten abzuschätzen, der für die Leistung eines Wahrnehmungssystems entscheidend ist. So wird die Metrik zur Bewertung der Qualität von LiDAR-Punktwolken verwendet, die zum Zweck des Domänenmappings erzeugt werden, bei dem Daten von einer Domäne in eine anderen übertragen werden. Dies ermöglicht die Wiederverwendung von Annotationen aus einer Quelldomäne in der Zieldomäne. In einem weiteren Feld der Domänenanpassung wird in dieser Dissertation eine neuartige Methode vorgeschlagen, die die Geometrie der Szene nutzt, um domäneninvariante Merkmale zu lernen. Die geometrischen Informationen helfen dabei, die Domänenanpassungsfähigkeiten des Segmentierungsmodells zu verbessern und ohne zusätzlichen Mehraufwand bei der Inferenz die beste Leistung zu erzielen. Schließlich wird eine neuartige Methode zur Erzeugung semantisch sinnvoller Objektformen aus kontinuierlichen Beschreibungen vorgeschlagen, die – mit zusätzlicher Arbeit – zur Erweiterung von Szenen verwendet werden kann, um die Erkennungsfähigkeiten der Modelle zu verbessern. Zusammenfassend stellt diese Dissertation ein umfassendes System für die Domänenanpassung und semantische Segmentierung von LiDAR-Punktwolken im Kontext des autonomen Fahrens vor

    THE NEXT STEP – OPEN PROTOTYPING

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    Software applications in the car are gaining in importance as a driver for innovation and value creation for the car manufacturers and their suppliers. These novel software functions, e.g., mobile services or car-to-car enabled applications, are increasingly designed and developed using early prototypes. Building on open innovation literature, this paper goes beyond extant knowledge on prototyping and proposes a novel paradigm of ‘open prototyping’. It assumes that organizations can and should use external input as well as internal input in form of prototypes, as the firms look to advance their technology. Set in the empirical field of the automotive industry, we follow a design-oriented research approach to design, develop and evaluate an open prototyping approach consisting of a toolkit and process. The open prototyping toolkit, HIMEPP, has a component-oriented architecture. Combined with the open prototyping process, it supports the development of diagonal high-fidelity prototypes together with persons from outside the R&D department. The study allows for generalizations to other industries and points to significant managerial as well as academic implications, which can be expected from opening the next step of the innovation process

    Inspection and Reconnaissance Micro-Rover for Use in Extraterrestrial Environments

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    The goal of this project is to design and implement a micro-rover capable of supporting a primary rover to complete mission specific tasks and objectives. This rover is designed with the intent of interfacing with many different robotic systems due to the ease of integration with Robot Operating System (ROS) and its small size. The project demonstrates the possibilities for smaller and lighter robotic rovers by exhibiting a small tele-operated, two-wheel, self-righting micro-rover with a HD video stream and sensor feedback for situational awareness designed for use in space applications. The micro-rover project proves the capabilities of creating a small inexpensive secondary rover to play a key supportive role, allowing the pair to complete mission objectives faster and more efficiently
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