Longitudinal Modeling and Preliminary Control of a Non-linear Flexible Launch Vehicle

This paper develops a non-linear longitudinal dynamical model of a flexible launch vehicle. The model captures the interaction between the rigid body and structural dynamics. The first bending mode is important as it affects the gimbal deflection angle. The equation of motion for the flexible launcher are derived from Lagrange's formalism. This model corresponds to a benchmark on which control law can be tested or designed. A typical application of this benchmark is presented in terms of non-linear control of the rotational dynamics. A Lyapunov based controller is design to control the attitude and damp the bending mode.