Optimal guidance for hypersonic reentry using inversion and receding horizon control

This study investigates the optimal guidance problem for reentry vehicles with focus on novel methods for nominal trajectory generation and tracking. To reduce the dimensionality of reentry trajectory optimisation problem, the inversion-based approach is utilised to partly eliminate the differential equations by reformulating the states and controls with some desired outputs. These outputs are parameterised with a mapped Chebyshev pseudospectral method, which is improved by conformal map and barycentric rational interpolation techniques in order to enhance the numerical accuracy for high-order derivatives of desired outputs. On the basis of the obtained nominal trajectory, a robust closed-loop guidance scheme is proposed using receding horizon control, whereas the associated two-point boundary value problem in each guidance cycle is readily solved by differential transformation method. Numerical simulations show that the proposed guidance scheme is feasible and effective for atmospheric reentry.