Abstract: Under the circumstance of the relative motion equation with parameter uncertainties, a new robust optimal terminal guidance law based on adaptive PID sliding mode control perturbation estimator is proposed for the problems existing in traditional optimal guidance law such as poor robustness and low impact accuracy induced by external disturbance and varying aerodynamic force. The sliding mode control perturbation estimator (SMCPE) is used to online eliminate the influence of perturbation, while the adaptive PID sliding mode control is used to remove chatting. The theoretic proof based on Lyapunov theorem stability and simulation results show that a demand\|satisfied performance index, high impact accuracy and stronger robustness is ensured.

Key words: Optimal terminal Guidance law, Sliding mode control perturbation estimator (SMCPE), Adaptive PID, StronG robustness