Robust Enhanced Model-Predictive Guidance for Impact Angle Constraints and Obstacle Avoidance

This article investigates the nonhoming guidance problem with impact angle constraints and obstacle avoidance under dynamic modeling errors and external disturbances. First, the obstacle is modeled based on reconnaissance aircraft information, and the allowable impact angle range is determined. Subsequently, an optimal trajectory with impact angle constraints and obstacle avoidance is shaped using the Bézier curve. A robust enhanced guidance law is then developed for precise tracking of the reference trajectory based on dynamic tube model-predictive control (DTMPC), where boundary layer sliding-mode control is used as an auxiliary controller to compensate for external disturbances. Compared with conventional DTMPC, the proposed method not only accounts for first-order differential equations with uncertainty characteristics in the computation of the robust control invariant tube but also explicitly considers system state constraints. This ensures safe trajectory tracking across a wide range of initial conditions while achieving high accuracy in satisfying impact angle constraints. Numerical simulations are performed to support our findings.