UAV Guidance with Concurrent Evasion and Terminal Angle Constraints ^†

This paper proposes a 3D terminal-constraint guidance framework for a UAV, modeled here as a missile-like attacker vehicle, that improves survivability against an incoming anti-air missile (AAM) while enforcing a prescribed terminal approach direction to a stationary ground target. The UAV uses Generalized Vector Explicit Guidance (GENEX) augmented by a rotating lateral sinusoidal bias that generates a barrel-roll-like evasive motion. The AAM employs classical proportional navigation (PNG). Both vehicles include a fifth-order binomial acceleration-command realization with explicit lateral saturation. Parametric simulations show that the proposed bias can increase survivability while maintaining terminal accuracy. Performance is primarily governed by the evasive frequency and amplitude, the guidance time constants, and the available lateral acceleration budget.