Impact Time Guidance to Capture Moving Targets in the Presence of Multiple Obstacles

We design a predefined-time convergent guidance scheme for an interceptor to intercept a moving adversary at a desired time of capture while avoiding obstacles in its path. We show that, unlike finite-time convergent guidance schemes wherein the upper bound of the settling time is dictated by the choice of controller parameters and is dependent on the initial engagement conditions, the proposed design has the flexibility of being independent of the initial engagement conditions, and the upper bound of the settling time can be supplied as a design parameter in the guidance command. We develop the proposed strategy for the interceptor based on deviated pursuit guidance and employ the paradigms of artificial potential fields in our baseline guidance scheme for obstacle avoidance, with features to tailor the rate and order of the repulsive potential function. We demonstrate that, under certain conditions, it is possible to achieve obstacle avoidance while ensuring a time-constrained interception. We substantiate our proposed design via simulations.