LESO Based Dynamic Surface Control for Hypersonic Flight Vehicle

In the presence of model parametric uncertainties and external disturbances, a LESO-based dynamic surface control approach is designed for the longitudinal model of Hypersonic Flight Vehicle (HFV). Via Nonlinear Dynamic Inversion (NDI) technique, the decoupling of altitude and velocity is realized. Combining with conventional back-stepping technique, a low pass filter (LPF) is introduced to attain the derivation of virtual control laws, which avoids the problem of “differentiation explosion”. A linear extended state observer (LESO) is designed for the precise estimation and compensation of "lumped disturbance" containing parametric uncertainties and external disturbances, which tremendously improves the ability of disturbance rejection of the system. The stability of the proposed approach is analyzed by means of Lyapunov theory. The simulation results demonstrate that the proposed methodology has good command tracking performance, and the approach is robust in the presence of lumped disturbances.