Modeling and Analysis of a 6-DOF Flexible Hypersonic Flight Vehicle

Abstract

The aerodynamic, structure and propulsion interactions in a six-degree-of-freedom (6-DOF) flexible hypersonic vehicle bring great challenges to vehicle modeling and control design. This paper focus on the modeling of a 6-DOF flexible hypersonic flight vehicle. The flexible dynamic and three-dimensional aerodynamic loads are calculated by using or combining an assumed modes method, variation theory and shock/expansion theory. A control-oriented nonlinear model (COM) is obtained using curve-fitted approximation of the forces and moments on the vehicle. The COM is then linearized about a steady flight condition, and the rigid/flexible dynamics and coupling of the 6-DOF vehicle model with aerodynamic, structure and propulsion interactions are analyzed comprehensively.