UAS Education at the French Civil Aviation University

International audienceThe French Civil Aviation University's (ENAC, Ecole Nationale de l'Aviation Civile) main objectives are to train personnel specialised in air transport, and to help these specialists adapt to civil aviation's evolution, such as the advent of Unmanned Air Systems (UAS) in our skies. This paper shows that in ENAC, education in UAS is carried out in the same way than education in manned aviation topics. The training is divided in main subjects, which are then allocated to each student population according to their future roles: engineers, air traffic controllers, technicians, etc. Teaching is led by skilled personnel and backed up by modern facilities and equipment. This allows ENAC to provide a competent, specialised work force, ready to work on all aspects of the emerging and disruptive UAS-based operations

Reducing Computational Cost in the Invariant Unscented Kalman Filtering For Attitude Estimation

This article proposes a new formulation to derive the invariant unscented Kalman filter (IUKF) algorithm for attitude estimation problem, where both state and sigma-point are considered as a transformation group parametrization of the filter. The detailed IUKF equations are presented in this article. The filter equations relie on the same ideas as the usual Unscented Kalman Filter (UKF), but it uses a geometrically adapted correction term based on an invariant output error. The specific interest of the proposed formulation is that only the invariant state estimation errors between the predicted state and each sigma point must be known to determine the predicted outputs errors. As we have already computed the set of invariant state errors during the prediction step, the computation cost to find the covariance matrix of the invariant state estimation in the update step is greatly reduced

Circular formation control of fixed-wing UAVs with constant speeds

In this paper we propose an algorithm for stabilizing circular formations of fixed-wing UAVs with constant speeds. The algorithm is based on the idea of tracking circles with different radii in order to control the inter-vehicle phases with respect to a target circumference. We prove that the desired equilibrium is exponentially stable and thanks to the guidance vector field that guides the vehicles, the algorithm can be extended to other closed trajectories. One of the main advantages of this approach is that the algorithm guarantees the confinement of the team in a specific area, even when communications or sensing among vehicles are lost. We show the effectiveness of the algorithm with an actual formation flight of three aircraft. The algorithm is ready to use for the general public in the open-source Paparazzi autopilot.Comment: 6 pages, submitted to IROS 201

The Invariant Unscented Kalman Filter

International audienceThis article proposes a novel approach for nonlinear state estimation. It combines both invariant observers theory and unscented filtering principles whitout requiring any compatibility condition such as proposed in the -IUKF algorithm. The resulting algorithm, named IUKF (Invariant Unscented Kalman Filter), relies on a geometrical-based constructive method for designing filters dedicated to nonlinear state estimation problems while preserving the physical invariances and systems symmetries. Within an invariant framework, this algorithm suggests a systematic approach to determine all the symmetry- preserving terms without requiring any linearization and highlighting remarkable invariant properties. As a result, the estimated covariance matrices of the IUKF converge to quasi-constant values due to the symmetry-preserving property provided by the invariant framework. This result enables the development of less conservative robust control strategies. The designed IUKF method has been successfully applied to some relevant practical problems such as the estimation of attitude for aerial vehicles using low-cost sensors reference systems. Typical experimental results using a Parrot quadrotor are provided in this pape

Proceedings of the International Micro Air Vehicles Conference and Flight Competition 2017 (IMAV 2017)

The IMAV 2017 conference has been held at ISAE-SUPAERO, Toulouse, France from Sept. 18 to Sept. 21, 2017. More than 250 participants coming from 30 different countries worldwide have presented their latest research activities in the field of drones. 38 papers have been presented during the conference including various topics such as Aerodynamics, Aeroacoustics, Propulsion, Autopilots, Sensors, Communication systems, Mission planning techniques, Artificial Intelligence, Human-machine cooperation as applied to drones

Design of a high performance MAV for atmospheric research

International audienceThis article presents the design of a mini UAV dedicated to atmospheric research with tight operational constraints coming from the end-users, which are the meteorologists associated to the project. Several aspects are covered in addition to the conceptual design of the frame itself and its manufacturing process. This includes the innovative launching system based on water rocket, the design of a 5-hole probe for wind and turbulence measurements, the new version of the on-board autopilot and finally the evaluation of a long range communication system. Preliminary results are presented to conclude the paper

Verifying the Mathematical Library of an UAV Autopilot with Frama-C

Ensuring safety of critical systems is crucial and is often attained by extensive testing of the system. Formal methods are now commonly accepted as powerful tools to obtain guarantees on such systems, even if it is generally not possible to formally prove the safety and correctness of the whole system. This paper presents an ongoing work on the formal verification of the Paparazzi UAV autopilot using the Frama-C verification platform. We focus on a Paparazzi mathematical library providing different UAV state representations and associated conversion functions and manage to prove the absence of runtime errors in the library and some interesting functional properties on floating-point conversion functions

Editorial IJMAV: Special issue IMAV 2017

IMAV 2017 has gathered more than 280 participants from 30 different countries including Asia, North, Central and South America, Europe, and Australia. The special issue IMAV 2017 includes a selection of the best papers nominated for the "Best Paper Award"