탄두효과 향상을 위한 최적 입사 기준선 유도기법 = Optimal Diveline Guidance Law for Terminal Impact-Angle Control Considering Warhead Effectiveness

다국어 초록 (Multilingual Abstract)

This thesis proposes an optimal diveline guidance (ODG) law to enhance warhead effectiveness of anti-surface missiles. Most existing approaches to terminal impact angle control problem are developed under the assumption that the missile-target relative motion can be described by a linearized state-space model. In practice, this assumption is frequently violated by model uncertainties due to large initial heading errors, imperfect or nonlinear flight dynamics, and limited missile maneuverability. As a result, terminal guidance performance is deteriorated and ricochet can occur during target interception, significantly reducing warhead effectiveness.
Motivated by this issue, a terminal impact angle control problem is addressed through geometric insight: locating the missile on the collision triangle defined by the desired diveline enables effective impact angle control. Accordingly, the missile-target relative motion is modeled as a linear time-varying (LTV) state-space model with the line-of-sight (LOS) rate and the heading error with respect to the diveline as the state variables. Thus, the terminal impact angle control problem is formulated as an optimal control problem that minimizes a weighted quadratic cost on the heading error and control effort, subject to the given LTV system and terminal constraints. Consequently, solving the resulting optimal control problem reduces to a modified Bessel differential equation, and the uniqueness and the convergence of the resulting ODG command are proved. A capture region is also derived to identify feasible initial conditions that satisfy the terminal constraints without acceleration saturation at interception. For real-time implementation of the ODG, the guidance gain expressed by a modified Bessel function is approximated using a sequence of time-to-go polynomials, ensuring continuity across time-interval transitions. Moreover, adjoint analysis confirms that the proposed guidance law shows less sensitivity to dynamic lag than the previous methods. Through nonlinear 3-DOF simulation including flight dynamics, acceleration limit, and target motion, it is demonstrated that the proposed scheme not only achieves superior impact angle control performance compared to existing techniques but also effectively suppresses ricochet, maximizing warhead effectiveness.

목차 (Table of Contents)

• 1.서론 1
• 1.1.연구배경 1
• 1.2.연구개요 및 학위논문 구성 3
• 2.최적 입사 기준선 유도 법칙 5
• 2.1.문제정의 5
• 2.2.최적 입사 기준선 유도기법 설계 7
• 2.2.1.ODG 문제의 해석 해 7
• 2.2.2.ODG 해의 수렴성과 유계성 14
• 2.2.3.ODG의 표적 요격영역 18
• 2.3.최적 입사 기준선 유도기법의 구현 20
• 2.4.최적 입사 기준선 유도기법의 특성 26
• 2.4.1.설계변수에 따른 궤적 특성 26
• 2.4.2.상대기하에 따른 궤적 특성 31
• 2.4.3.Adjoint 해석 40
• 3.충돌각 제어 성능분석 43
• 3.1.시뮬레이션 조건 44
• 3.2.정지표적에 대한 성능분석 44
• 3.3.이동표적에 대한 성능분석 49
• 4.결론 56
• 4.1.주요 수식 유도 과정 57
• 4.1.1.변형 Bessel 함수의 기본 성질 57
• 4.1.2.∆(τ) 유도과정 58
• 4.1.3.M1(τ) 및 M2(τ) 유도과정 59
• References 60