Composite adaptive dynamic programming for missile interception systems with multiple constraints and less sensor requirement

The adaptive integrated guidance and control issue of missiles with less sensor requirement is investigated in the optimal stabilization problem of an uncertain nonlinear system subjected to state and input constraints. The nonlinear system with partially unmeasurable states is transformed into the non-strict feedback form, firstly. Then, an adaptive observer is designed to approximate the full states, where a disturbance estimator is incorporated to suppress the unmatched external disturbances. Next, by employing a Barrier Lyapunov Function (BLF) and an auxiliary system to tackle the multiple constraints, an adaptive feedforward controller is raised to reduce the stabilization issue of the nonlinear system in non-strict feedback form to the equivalent control problem of an affine nonlinear system. Subsequently, an optimal controller is derived by utilizing adaptive dynamic programming (ADP) theory. The system stability is rigorously proved by using Lyapunov theory. Finally, simulations are performed to validate the effectiveness of the proposed control strategy.