This paper presents a centralized and strategical approach for Unmanned aircraft systems Traffic Management (UTM) to design optimal 4D trajectories minimizing the total flight time of all vehicles over a given time window. Potential losses of pairwise separation between vehicles are modeled and solved. A 4D trajectory is modeled by choosing an horizontal path (with an associated nominal speed profile), a departure slot and a cruising flight level. The problem is formulated as a mixed-integer linear program. A two-step solution approach is proposed that takes into account operational requirements, such as late flight intention deposits, or static and dynamic geofences; and...

We present a semiclassical gravity in the framework of the double scale theory, a new interpretation of quantum mechanics which expands on the de Broglie-Bohm (dBB) theory. In this interpretation, any quantum system is associated with two wave functions, one external and one internal. The external wave function drives the center-of-mass, as in the dBB theory, and spreads with time. The internal wave function corresponds to the density of an extended particle. It remains confined in space and its average position corresponds to the center of mass of the particle. We define, for an N-body system, new semi-classical gravity equations called Einstein-de Broglie equations. The...

This paper introduces an optimization model for machining free-form surfaces. It involves one categorical decision variable and continuous decision variables. Its objective function is partially separable. It is composed of two blackboxes: a clustering blackbox that outputs a partition of the surface into K zones, and K independent blackboxes, each of which outputs a machining time for a zone. This blackbox optimization problem is solved with the state-of-the-art software NOMAD. In order to improve the performance of the optimization process, we propose several surrogates of the machining-time blackboxes. Some of these surrogates are simple numerical approximations of the...

We present a semiclassical gravity in the framework of the double scale theory, a new interpretation of quantum mechanics which expands on the de Broglie-Bohm (dBB) theory. In this interpretation, any quantum system is associated with two wave functions, one external and one internal. The external wave function drives the center-of-mass, as in the dBB theory, and spreads with time. The internal wave function corresponds to the density of an extended particle. It remains confined in space and its average position corresponds to the center of mass of the particle. We define, for an N-body system, new semi-classical gravity equations called Einstein-de Broglie equations. The...

The aircraft conflict detection and resolution problem has been addressed with a wide range of centralised methods in the past few decades, e.g. constraint programming, mathematical programming or metaheuristics. In the context of autonomous, decentralized collision avoidance without explicit coordination, geometric methods provide an elegant, cost-effective approach to avoid collisions between mobile agents, provided they all share a same logic and a same view of the traffic. The Optimal Reciprocal Collision Avoidance (ORCA) algorithm is a state-of-the art geometric method for robot collision avoidance, which can be used as a Detect & Avoid logic on-board aircraft or...

Dans ce papier, le logiciel SSW-2D pour la modélisation de la propagation par méthode split-step wavelet (SSW) est présenté. SSW améliore la méthode split-step Fourier (SSF) classiquement utilisée pour la modélisation déterministe de la propagation sur de grandes scènes. Cependant, coder cette méthode s'avère bien plus complexe et nécessite une compréhension fine de la décomposition en ondelettes. C'est pourquoi un logiciel clé en main s'avère utile pour permettre à la communauté de la propagation de s'approprier SSW. Ce logiciel open source (sous licence GNU GPL V3) vient avec une interface graphique pour une utilisation basique. Il est aussi possible de passer par des...

Vertical takeoff and landing (VTOL) vehicles are among the most versatile UAVs, appropriate for various missions. Given that there are still open challenges regarding the VTOL design, this paper presents the full development and test cycle of a tail-sitter. IMAV 2022 competition rules were used to define the mission. A multidisciplinary design and optimization strategy was defined with the goal of maximizing competition score considering design, manufacturing, and competition constraints. The resulting vehicle was designed to fly at 18 m/s while carrying 200 g of payload with a total weight of approximately 720 g. It flew for roughly 13 minutes at IMAV2022, helping its...

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This paper presents the internal architecture of a Modifiable Off-the-Shelf open-source autopilot. We show starting from a set of functional and hardware requirements why most autopilots use as a core thread a main loop acting as a nonpreemptive static scheduler, reacting to external events, some solicited, some unsolicited (but expected). We explain how the type of bus used to communicate with the sensor impacts the nature of the events received from the sensors (solicited or not). We show that depending on the workload that a main loop iteration has to handle, the execution time of an iteration can be larger than the period, creating potential delays in the attitude...