Soutenance de thèse de Sofiane Pineau


5 septembre 2024    
10h00 - 13h00

CRAN - Longwy
186 Rue de Lorraine, Cosnes-et-Romain, 54400

Type d’évènement

Titre de la thèse :Dynamique de vol et commande non-linéaire adaptative pour projectiles guidés

Résumé :

155 mm spin-stabilized ammunitions commonly used in artillery, suffer from a high ballistic dispersion
toward the target due to uncertain launch conditions and wind disturbances. To reduce this lack of
precision, a concept of a dual-spin guided projectile geared with a course-correction fuse is investigated.
This is an innovative and low-cost solution which consist of equipping existing shells with a roll-decoupled
guidance fuse embedding up to four aerodynamic control surfaces called canards. The fuse embeds also
all necessary sensors (IMU, magnetometers, and GNSS), a control law and a guidance law.
The main control strategy used in the literature for dual-spin guided projectiles is called gain-scheduling.
This methodology is based on the local linearization of the projectile dynamics around a fixed number of
flight points in order to synthetize a nonlinear scheduled controller. Gain-scheduling is time-consuming
due to the large number of local controllers to be tuned, and does not guarantee global performance and
stability over the entire flight envelope.
Therefore, the main objective of this thesis is to establish a generic and rapid design methodology
for guided projectiles autopilots with guaranteed performance and robustness to parameter uncertainties
through the whole flight envelope.
To achieve this objective, first, the nonlinear modelling of the projectile was conducted and a ballistic
simulator was designed in the Matlab/Simulink environment. Then, the Incremental Nonlinear Dynamic
Inversion (INDI) control method was used to design the roll, pitch, yaw and load factor autopilots required
to correct the projectile’s trajectory. A tuning methodology was designed using digital control analysis
tools and mixed-sensitivity synthesis to meet the tuning requirements. Finally, to deal with the parametric
uncertainties of the projectile model and guarantee the overall performance of the control system, the
INDI autopilots were augmented with an adaptive layer. Non-linear simulations of guided trajectories
were used to validate the nominal behavior of the INDI control law and the increased robustness provided
by the adaptive augmentation

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