Structural topology optimization aims to design mechanical structures by seeking the optimal material layout within a given design space. Within this framework, this paper addresses the minimization of the structural mass under stress and buckling constraints, formulated as a nonlinear combinatorial optimization problem. An algorithm is proposed for such a problem, that follows a topological gradient-based approach. The adjoint method is applied to efficiently compute the constraint gradients. An iterative algorithm for buckling analysis, featuring low memory requirements, is also proposed. Numerical results, including a real application arising in the aeronautical field...

Precise positioning with a stand-alone GPS receiver or using differential corrections is known to be strongly degraded in a constrained environment (urban or sub-urban conditions) due to frequent signal masking, strong multipath effect, frequent cycle slips on carrier phase, etc. The objective of this work is to explore the possibility of achieving precise positioning with a low-cost architecture: using multiple low-cost receivers with known geometry to enable the vehicle attitude determination and RTK performance amelioration. In this paper, we firstly use a method that includes an array of receivers with known geometry to enhance the performance of the RTK in different...

The regular monitoring of operations in both movement areas (taxiways and runways) and non-movement areas (aprons and aircraft parking spots) of an airport, is a critical task for its functioning. The set of strategies used for this purpose include the measurement of environmental variables, the identification of foreign object debris (FOD), and the record of statistics of usage for diverse sections of the surface. According to a group of airport managers and controllers interviewed by us, the wide monitoring of most of these variables is a privilege of big airports due to the high acquisition, installation and maintenance costs of most common technologies. Due to this...

In this work, we show a construction of a Hessian foliation on a statistical manifold. Our results provide conditions, under which the compacts hessian leaves (up to diffeomorphism) are quotients of homogeneous convex cones.

To better guide people to evacuate in a given area, this paper proposes a multi-agent emergency evacuation simulation system for the adjustment of people’s downward flow in a dynamic disaster environment. The main goal of this paper for managing emergency evacuation is to build a basic model that can simulate the location distribution of people, the speed of personnel, the pedestrian flow, road congestion and other situations. The proposed system mainly combines two multi-agent-based methods, i.e., cellular automata (CA) model and ripple-spreading algorithm (RSA). The CA model simulates the road network and the flow of people, the improved RSA calculates the optimal...

Les micro drones à capacités de vol de transition, ou simplement HMAVs (de l’anglais Hybrid MicroAir Vehicles), regroupent les principales caractéristiques aérodynamiques des configurationsà voilure fixe, en termes d’endurance, avec les capacités de décollage et d’atterrissage verticaldes voilures tournantes afin d’effectuer cinq phases de vol au cours de ses missions, telles quele décollage vertical, le vol de transition, le vol en croisière, le vol stationnaire et l’atterrissagevertical. Cette nouvelle classe de micro drones a un domaine de vol plus large que les microdrones conventionnels, ce qui implique de nouveaux défis pour les automaticiens et les...

This paper presents a novel open source design of the Y-shaped hexarotor Unammend Aerial Vehicle (UAV), and proves both in theory and real experiments its robustness to the failure of any of its propellers. An intuitive geometrical interpretation of UAV static hovering ability is presented, through which the robustness of different coplanar/collinear hexarotor designs is analyzed. Following the presented geometrical interpretation, we also show a method to render the Star-shaped hexarotor robust to the failure of some of its propellers, while showing its incapability to static hover in the case of the failure of any of its propellers. Finally, the efficiency of the Y...

The methodology presented can improve safe and secure software development. The SNG Router case study extends aeronautical network capabilities. Additional tool chains to complete formal checking toolkit is also presented. A compatibility check is performed between methodology and D0178C. An extension of network security requirements for router SNG is presented.

Cette thèse s'inscrit dans les domaines de l’apprentissage statistique et de l'analyse d'incertitude dans le cadre d'un problème de thermodynamique chimique. On s'intéresse à deux problèmes liés à la reconstruction d'une fonction $f$ multidimensionnelle : en premier lieu, un problème de propagation de l'incertitude dans le cadre du modèle linéaire bayésien ; en second lieu, la reconstruction non paramétrique d'une fonction par maximisation d'un critère d'analyse convexe. La spécificité du problème de thermodynamique chimique considéré dans cette thèse réside dans la structure compliquée des données : les données d'assimilation ne sont pas des observations directes de la...