ESA GNC Conference Papers Repository

Non linear dynamic inversion has been extensively applied to reentry vehicles in the past few years. Astrium Space Transportation implemented control law based on Feedback Linearization on Atmospheric Reentry Demonstrator (ARD). The method has been extended to ESA lifting body hypersonic reentry. Due to the large uncertainties, the method was not completely satisfactory for the lateral domain and augmented filtering was considered. To synthetize such filters, two methods have been analyzed. First method consists in analytical worst case loop shaping. Second method consists in an original method based on LPV polytopic synthesis. The method is very efficient to guarantee Hinfinity performance on the whole domain of uncertainties. LPV polytopic synthesis augmented with worst case LMIs stacking is a straightforward method which converges very rapidly to an optimal solution. The method is also compared to standard Hinfinity synthesis. The paper concludes on a detailed comparison of augmented Loop Shaping and augmented LPV polytopic synthesis methods both in frequential and time domains.