Gliding trajectory tracking guidance law based on indirect radau pseudospectral method

A full-state nominal trajectory tracking guidance scheme, in which the optimal feedback control law is solved by indirect Radau pseudospectral method, for hypersonic vehicle gliding guidance is proposed. Based on the Pontryagin maximum principle, the state regulator problem for a linear time-varying system converted from the original trajectory tracking problem is transformed into the linear two point boundary value problem. The indirect Radau pseudospectral method is applied to solve the obtained linear two point boundary value problem, and the closed-loop trajectory tracking guidance law easily implemented online is designed on the basis of the resulting optimal feedback control law. Simulation results indicate that the proposed guidance scheme is robust to the presence of large initial state deviations and limited flight environment parameter disturbances, and satisfies real-time requirement.