Samir Bennani

Microvibration Attenuation based on H∞/LPV Theory for High Stability Space Missions

This paper presents a LPV (Linear Parameter Varying) solution for a mixed passive-active architecture used to mitigate the microvibrations generated by reaction wheels in satellites. In particular, H∞/LPV theory is used to mitigate low frequency disturbances, current baseline for high frequency microvibration mitigation being based on elastomer materials. The issue of multiple harmonic microvibrations is also investigated. Simulation results from a test benchmark provided by Airbus Defence and Space demonstrate the potential of the proposed method.

Preliminary AOCS Design for Pointing Budget Assessment of the BIOMASS Candidate Earth Explorer Core Mission

Abstract This paper presents the preliminary assessment of the attitude control design and performance for a baseline concept of the Biomass mission, a candidate for ESAs next Earth Explorer Core Missions. This satellite concept, as conceived at the end of the Phase 0 studies, has a 20-meter P-band antenna, for which the impact of high flexibility and uncertainty must be assessed. As a result, a rapid prototyping procedure has been established to assess the feasibility of various performance and robustness requirements at an early stage of the satellites development. This has been done by incorporating a covering uncertainty model to reflect the structural dynamics with associated tolerances. This allows the use of a control design solely based on rigid dynamics, resulting in a low-order control solution, for which coverage is demonstrated by means of multivariable robust performance and stability margins expressed in the structured singular value metrics. Using non-linear simulations, we demonstrate the suitability of the robust design approach to the selected satellite concept.

Sloshing-aware attitude control of impulsively actuated spacecraft

In this tutorial paper we present a novel modeling methodology to derive a nonlinear dynamical model which adequately describes the effect of fuel sloshing on the attitude dynamics of a spacecraft. We model the impulsive thrusters using mixed logic and dynamics leading to a hybrid formulation. We design a hybrid model predictive control scheme for the attitude control of a launcher during its long coasting period, aiming at minimising the actuation count of the thrusters.

Robust Rocket Navigation with Sensor Uncertainties: Vega Launcher Application

This paper presents the practical use of Kalman filtering by combining global navigation satellite system signals with inertial sensor measurements in a sensor fusion scheme for rockets. A robust S...

A hybrid model predictive control approach to attitude control with minimum-impulse-bit thrusters

This paper studies an important aspect of attitude control for a launchers upper stage: the minimum impulse bit (MIB), that is, the minimum torque that can be exerted by the thrusters. We model this effect using principles of hybrid systems theory and we design a hybrid model predictive control scheme for the attitude control of a launcher during its long coasting period, aiming at minimizing the number of thrusters actuations. We apply the proposed methodology to a nonlinear model of a typical upper stage with multi-payload capability.