Hybrid Nonlinear Model Predictive Control of a Flexible Satellite

Document Type : Research Article

Authors

1 Department of Aerospace Engineering, University of Isfahan, Isfahan, Iran

2 Department of Aerospace Engineering, Sharif University of Technology, Tehran, Iran

3 Satellite Systems Institute, Iranian Space research Center, Tehran, Iran

Abstract

This paper provides a hybrid control strategy for the aim of nullifying the vibration of flexible appendages in satellite structures. These vibrations often occur during the deployment of satellite panels. To maintain performance and ensure attitude stability, a robust control framework is essential. To achieve this, piezoelectric actuators are incorporated into the panels to actively suppress structural vibrations. Lyapunov Nonlinear Model Predictive Control (LNMPC) is introduced in order to guarantee satellite stability and robustness. This algorithm is similar to the Piece-Wise Affine(PWA) method, but the nonlinear dynamics of the system is used instead of linearization. Additionally, Anti-Unwinding Sliding Mode Control is employed into this algorithm and combined with LNMPC to neutralize the vibration actively, furthermore this composite controller assists to control both kinematics and dynamics properly also steering the reaction wheels to zero after every maneuver to save energy in the presence of uncertainty, external disturbance and actuators dynamics considered into the algorithm. Furthermore, close loop stability analysis is provided by utilizing a candidate Lyapunov function.

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