Event-trigger based adaptive-robust guidance strategy with input saturation

Over the last few decades, the computational capabilities of the state-of-the-art processors have increased extensively and are now capable of performing multiple parallel computations. However, due to constraint on cost, weight, and space, they are not generally installed as an on-board processor of an interceptor. This limitation of the computational capabilities of the missile processor is addressed in this paper, by designing an event-triggered strategy which reduces the number of control updates. In addition to achieving the primary objective of capturing the target, the proposed guidance strategy enables the interceptor to tackle external disturbances that it encounters. Further the conservative assumption of apriori knowledge about the upper bound of the disturbances is eliminated by adaptively tuning the gains of the proposed guidance law. Input saturation has also been considered on the control effort of the missile so as to be consistent with most practical interceptor systems. Lyapunov theory has been used to demonstrate asymptotic stability of the closed-loop system states under the proposed event-triggered control scheme. Numerical simulations for the guidance strategy on the commonly occurring tail-chase and head-on engagement scenarios are performed along with a comparative performance analysis with the periodic time-triggered technique.