Conception et réalisation d'un système efficace de communication et de coordination au sein d'une flotille de drones aquatiques de surface
Auteur / Autrice : | Yoann Hervagault |
Direction : | Laurent Lefèvre, Darine Kaddour, Ionela Prodan, Pierre Lemaître-Auger |
Type : | Thèse de doctorat |
Discipline(s) : | Automatique et productique |
Date : | Soutenance le 17/09/2019 |
Etablissement(s) : | Université Grenoble Alpes (ComUE) |
Ecole(s) doctorale(s) : | École doctorale électronique, électrotechnique, automatique, traitement du signal (Grenoble ; 199.-....) |
Partenaire(s) de recherche : | Laboratoire : Laboratoire de conception et d'intégration des systèmes (Valence ; 1996-....) |
Jury : | Président / Présidente : Eric Duviella |
Examinateurs / Examinatrices : Yvan Duroc | |
Rapporteurs / Rapporteuses : Tchanguiz Razban-Haghighi, Christophe Louembet |
Mots clés
Résumé
The work described herein concerns the development of a communication strategy for a fleet of USVs (Unmanned Surface Vehicles). This project's aim is to improve the performances of the SPYBOAT system, developed by the French company CT2MC to perform environmental monitoring missions in fresh waters. In order to successfully fulfill their task, autonomous surface vehicles must be able to maintain a reliable communication link. This thesis's goal is twofold and complementary:- propose the design of an antenna dedicated to the particular conditions of an USV environment and contained in the vessel's hull,- take into account the effective radio ranges and the limited onboard computing resources to develop an admissible deployment strategy.First, the system under study is identified through experiments performed in the Bourget Lake. The differential flatness property of the model is also proved for further use in the computation of reference trajectories.Subsequently, the characteristics of the USV are described from a radio-frequency point of view. The environmental conditions involved by the water proximity, the low heights of the antennas and the high density of conductive materials in unmanned systems are very challenging. The selected antenna configuration is a planar antenna array, composed of three elementary semi-circular monopoles. Low-height measurements over the ground in open space, in good agreement with simulations, have proven that the proposed antenna and the currently used wire antennas exhibit good electrical performances. Antennas simulations have shown that the radiation pattern loses its omnidirectional property when placed in the vessel's hull due to the reflexions on the embedded equipment, and multiple antennas are required to maintain a reliable communication link.Finally, an algorithm able to compute a feasible reference trajectory for a fleet of USVs is proposed. The flatness-based optimization algorithm takes into account communication constraints to ensure that none of the agents in the network becomes isolated. The optimization problem is solved offline to reduce the computation task of the embedded controller. Then, the trajectory tracking algorithm is implemented online via an LQR (Linear Quadratic Regulator) controller which has been simulated and successfully experimented under various scenarios over the real platforms of CT2MC. The experimental tests show that the pre-established communication constraints are preserved while minimizing the tracking error.