Composite Zero-Effort-Miss Guidance with Predictor–Corrector Steps for Ballistic Interception

Abstract

In this paper, a midcourse guidance law for exoatmospheric interception using a solid-propellant rocket is presented. Existing guidance laws based on the zero-effort-miss concept lack consideration for remaining thrust, potentially resulting in the excessive magnitude and rate of the thrust direction command. To address this issue, the zero-effort-miss concept is combined with an iterative predictor–corrector-based guidance law that is adapted for solid-propellant rockets. To apply the iterative predictor–corrector-based guidance law to the interception problem with a solid-propellant rocket, a composite zero-effort-miss concept is introduced, and the correction step is formulated as an online convex optimization problem. The composite zero-effort-miss consists of two zero-effort-misses. One miss is obtained from current state and the other miss is obtained from predicted state at burnout. Those render the proposed guidance law robust to thrust uncertainty allow for a noniterative approach and eliminate the singularity problem. Also, the proposed guidance law reduces maneuvering during the early part of the midcourse phase, leading to less velocity loss, and resolves intercept performance degradation due to the rate limit of thrust vectoring. Numerical simulations comparing the proposed method with the modified zero-effort-miss guidance demonstrate its effectiveness and robustness.