Composite Design of Disturbance Observer and Reentry Attitude Controller: An Enhanced Finite-time Technique for Aeroservoelastic Reusable Launch Vehicles

摘要

In this paper, we concern the reentry attitude control (RAC) scheme design for aeroservoelastic reusable launch vehicles (RLVs). The basic problem is to derive a RAC technique such that the aeroservoelastic RLV can achieve a robust tracking of the desired attitudes in a rapid way despite the existence of parameter uncertainties as well as external disturbances. Following from the elastic equations and attitude dynamics of the RLV, we formulate a control-oriented model in matched structure. Our main contribution is threefold. First, using the fast terminal sliding mode algorithm, the disturbance observers are designed to generate the estimation of uncertainties and disturbances, while can ensure the estimation errors converge to the origin within a timely fashion. Second, the finite-time super-twisting sliding mode control method and cascade-loop design are developed to incorporate into the new RAC strategy; hence it leads to a guaranteed tracking ability of the reentry attitude in a timely way. Third, a finite-time integral sliding mode filter is proposed in the control scheme such that the virtual input signal can be tackled well. Additionally, numerical simulations of a dynamic model for the RLV are implemented to demonstrate the effectiveness and performance of the developed RAC strategy and furthermore its aeroservoelastic properties.