The Energy Application Domain Extension for CityGML: enhancing interoperability for urban energy simulations

The road towards achievement of the climate protection goals requires, among the rest, a thorough rethinking of the energy planning tools (and policies) at all levels, from local to global. Nevertheless, it is in the cities where the largest part of energy is produced and consumed, and therefore it makes sense to focus the attention particularly on the cities as they yield great potentials in terms of energy consumption reduction and efficiency increase. As a direct consequence, a comprehensive knowledge of the demand and supply of energy resources, including their spatial distribution within urban areas, is therefore of utmost importance. Precise, integrated knowledge about 3D urban space, i.e. all urban (above and underground) features, infrastructures, their functional and semantic characteristics, and their mutual dependencies and interrelations play a relevant role for advanced simulation and analyses. As a matter of fact, what in the last years has proven to be an emerging and effective approach is the adoption of standard-based, integrated semantic 3D virtual city models, which represent an information hub for most of the abovementioned needs. In particular, being based on open standards (e.g. on the CityGML standard by the Open Geospatial Consortium), virtual city models firstly reduce the effort in terms of data preparation and provision. Secondly, they offer clear data structures, ontologies and semantics to facilitate data exchange between different domains and applications. However, a standardised and omni-comprehensive urban data model covering also the energy domain is still missing at the time of writing (January 2018). Even CityGML falls partially short when it comes to the definition of specific entities and attributes for energy-related applications. Nevertheless, and starting from the current version of CityGML (i.e. 2.0), this article describes the conception and the definition of an Energy Application Domain Extension (ADE) for CityGML. The Energy ADE is meant to offer a unique and standard-based data model to fill, on one hand, the above-mentioned gap, and, on the other hand, to allow for both detailed single-building energy simulation (based on sophisticated models for building physics and occupant behaviour) and city-wide, bottom-up energy assessments, with particular focus on the buildings sector. The overall goal is to tackle the existing data interoperability issues when dealing with energy-related applications at urban scale. The article presents the rationale behind the Energy ADE, it describes its main characteristics, the relation to other standards, and provides some examples of current applications and case studies already adopting it

How to Produce a Reference Trajectory for Studying GNSS Errors in Urban Environments

International audienceVery active research investigations in the domain of terrestrial navigation have to face the problem to establish the true trajectory, to which relevant comparison could be made. Digital maps, despite their increasing accuracy, do not solve the problem. After a brief introduction of the general frame of the study (i.e. navigation with GPS EGNOS in urban environments), the authors present the instrumentation they set-up on board a test vehicle, basedon IXSEA LandINS inertial measurement unit hybridized with kinematic GPS and odometry. The reference trajectory obtained is analysed, with the aim of qualifying its accuracy

How to Assess and Improve Satellite Positioning Performances in Urban Environments

International audienceSatellite positioning performances are critical for transport liability applications such as road user charging, or pay per use assurance. The scientific community has focused for several years on environments with favorable conditions (aviation, maritime, rural) and is now addressing transport applications including urban areas. This is the case of this paper that presents the result of a study co-financed by the National French Space Agency(CNES). This study aimed first to collect the positioning data in urban area of several GPS/EGNOS receivers (more than 1,5 millions of positions) in addition to their associated satellite raw data and the reference positions. Its goal was secondly to assess the performance using classical positioning algorithms and last to propose and assess improved algorithms.The authors present first how to obtain the true trajectory necessary for the performance assessments. The instrumentation they set-up on board a test vehicle is based on IXSEA LandINS inertial measurement unit hybridized with kinematics GPS and odometry. The reference trajectory obtained is analyzed, with the aim of qualifying its accuracy. Based on these measurements, the authors then present the performance improvements obtained using different techniques, in particular 2D techniques to improve availability in difficult area such as narrow streets, smoothing technique to optimize the filtering and local error modeling technique to assess in particular disturbing multipath effects.Thanks to the ground truth obtained in this benchmark, the authors demonstrate that these techniques bring a significant improvement to position data performances, enlarging that way the spectrum of liability-critical road transport applications in urban areas

Developpement Durable et réseau IoT : l'équation est possible, Exemples de projets

International audienceDeveloppement Durable et réseau IoT : l'équation est possible, Exemples de projet

Developpement Durable et réseau IoT : l'équation est possible, Exemples de projets

International audienceDeveloppement Durable et réseau IoT : l'équation est possible, Exemples de projet

Système de surveillance de la qualité de l’air basé sur des capteurs embarqués sur vélo : projet AIR’O X AIR BREIZH

Cette communication décrit la réalisation d’un projet étudiant (projet Air’o) destiné au suivi de la pollution de l’air en collaboration avec l’association Air Breizh. Ce projet a été initié pendant l’année universitaire 2019-2020 lors de la 2ème année ingénieur (niveau M1) au sein du département « électronique et télécommunications » de l’INSA de Rennes. Le but du projet est de proposer une mesure de la qualité de l’air par l’intermédiaire de capteurs embarqués sur des vélos. Une transmission de la position du capteur ainsi que la mesure de pollution en temps réel via le réseau LoRaWAN (Long Range Wide-area Network) permet de localiser les niveaux de pollution tout au long du parcours du vélo. Ce suivi de la qualité de l’air s’effectue par la récupération des données (pollution, position) sur un serveur dédié. Une application spécifique est développée afin de situer géographiquement les niveaux de pollution enregistrés. La réalisation d’un prototype est présentée ainsi que la transmission des informations. Des premiers résultats indiquent la pertinence du concept développé