• 제어로봇시스템학회논문지
• /
• 제14권1호
• /
• pp.88-94
• /
• 2008

In this paper, a design method of a missile guidance command is presented considering the dynamics of missile control systems. The design of a new guidance command is based on the well-known PNG(propotional navigation guidance) laws. The missile control system dynamics cause the time-delays of the PN guidance command and degrade the performance of original guidance laws which are designed under the assumption of the ideal missile control systems. Using a backstepping method, these time-delay effects can be compensated. In order to implement the guidance command developed by the backstepping procedure, it is required to measure or calculate the successive time-derivatives of the original guidance command, PNG and other kinematic variables such as the relative distance. Instead of directly using the measurements of these variables and their successive derivatives, a simple disturbance observer technique is employed to estimate a guidance command described by them. Using Lyapunov method, the performance of a newly developed guidance command is analyzed against a target maneuvering with a bounded and time-varying acceleration.

• Journal of the Korean Society for Industrial and Applied Mathematics
• /
• 제19권3호
• /
• pp.217-234
• /
• 2015

In this tutorial the theoretical background of LQ optimal guidance is reviewed, starting from calculus of variations. LQ optimal control is then introduced and applied to missile guidance to obtain the basic form of LQ optimal guidance laws. Extension of LQ optimal guidance methodology for handling weighted cost function, dynamic lag associated with the missile dynamics and the autopilot, constrained impact angle, and constrained impact time is also described with a brief discussion on the asymptotic properties of the optimal guidance laws. Furthermore, an introduction to polynomial guidance and generalized impactangle-control guidance, which are closed related with LQ optimal guidance, is provided to demonstrate the current status of missile guidance techniques.

• International Journal of Aeronautical and Space Sciences
• /
• 제9권2호
• /
• pp.87-97
• /
• 2008

Modem anti-ship missiles employ complex and sophisticated guidance laws to hit the target and enhance their survivability by executing additional maneuvers. However, such maneuvers may cause the target to move out of the missile seeker's Field-Of-View (FOV). Maintaining seeker lock-on during an engagement is a critical factor for missile guidance. In this paper, a guidance law switching logic that maintains seeker lock-on and a simple guidance law that keeps the target look angle of the seeker constant is proposed. The proposed method can be used for the terminal homing phase, and can be switched from any kind of guidance laws if a proper switching condition is satisfied. The minimum and maximum flight time calculation method in consideration of the missile maneuver limit and the FOV of the seeker is also provided.

• 한국항공우주학회지
• /
• 제36권7호
• /
• pp.658-665
• /
• 2008

본 논문에서는 유도탄 응답지연을 고려한 실용적인 유도법칙을 제시한다. 유도탄의 속도벡터 방향을 조종할 수 있는 자세제어방식 autopilot을 갖는 유도탄을 고려하고, 최적제어이론을 적용하여 유도탄 응답특성에 따른 여러 가지 최적유도법칙을 유도할 수 있었으며, 실제적용 시의 문제점을 고려한 효율적인 유도법칙을 제안한다.

• International Journal of Aeronautical and Space Sciences
• /
• 제7권2호
• /
• pp.1-13
• /
• 2006

The Lyapunov stability theory has been known inadequate to prove capturability of guidance laws because the equations of motion resulted from the guidance laws do not have the equilibrium point. By introducing a proper transformation of the range state, the original equations of motion for a stationary target can be converted into nonlinear equations with a specified equilibrium subspace. Physically, the equilibrium subspace denotes the direction of missile velocity to the target. By using a single Lyapunov function candidate, capturability of several PN laws for a stationary target is then proved for examples. In this approach, there is no assumption of the constant speed missile. The proposed method is expected to provide a unified and simplified scheme to prove the capturability of various kinds of guidance laws.

• 한국군사과학기술학회지
• /
• 제1권1호
• /
• pp.211-218
• /
• 1998

As a part of trajectory modulation to increase system survivability and terminal effectiveness, impact angle control is required in the terminal phase of tactical missile systems. The missile systems are not allowed to have high altitude to reduce probability of detection by sensors of missile defense systems. In this paper, an analytic form of a time-optimal control law is suggested in the case of constrained missile maneuverability and impact angle under the assumption of a zero-lag autopilot. The control law is obtained by establishing optimal missile-target engagement geometry in the vertical plane. Extension of the law for missiles with autopilot response lags requiring a numerical solution is studied by introducing an iterative algorithm for optimal switching time determination of which the initial switching instants are obtained from the analytic solution. Also suggested is a closed-form impact angle control law derived by an energy-optimal approach. The performances of the proposed guidance laws are evaluated by a series of computer runs.

• Journal of the Korean Society for Industrial and Applied Mathematics
• /
• 제19권3호
• /
• pp.305-325
• /
• 2015

In this paper, missile homing guidance laws to control the impact angle and time are proposed based on the polynomial function. To derive the guidance commands, we first assume that the acceleration command profile can be represented as a polynomial function with unknown coefficients. After that, the unknown coefficients are determined to achieve the given terminal constrains. Using the determined coefficients, we can finally obtain the state feedback guidance command. The suggested approach to design the guidance laws is simple and provides the more generalized optimal solutions of the impact angle and time control guidance.

• Journal of Mechanical Science and Technology
• /
• 제16권6호
• /
• pp.770-775
• /
• 2002

In this paper, a game optimal receding horizon guidance law (GRHG) is proposed, which does not use information of the time-to-go and target maneuvers. It is shown that by adjusting design parameters appropriately, the proposed GRHG is identical to the existing receding horizon guidance law (RHG), which can intercept the target by keeping the relative vertical separation less than the given value, within which the warhead of the missile is detonated, after the appropriately selected time in the presence of arbitrary target maneuvers and initial relative vertical separation rates between the target and missile. Through a simulation study, the performance of the GRHG is illustrated and compared with that of the existing optimal guidance law (OGL).

• 항공우주시스템공학회지
• /
• 제18권2호
• /
• pp.1-11
• /
• 2024

정보공유 기반의 네트워크 협업 유도탄에 대한 상대 충돌 각 유도기법을 불확실성과 외란이 존재하는 시스템에 적용했다. 협업 유도탄 시스템은 전이 축소 방향성 비순환 그래프로 표현되며, 그 구조에 따라 유도된 중앙집권형 및 분산형 유도기법을 소개했다. 또한, 소개된 유도기법을 유도탄의 통신 구조와 시스템 잡음 유무에 따라 비교하여 그 관계를 분석했다. 상대 충돌 각 제어 임무에서 분산형 정보공유 유도기법의 효과를 분석하기 위해 시스템 동역학에 잡음이 포함된 다수의 유도탄이 불확실성이 포함된 예상 요격 위치에 유도되는 상황을 가정하였다. 다양한 임무 환경에 대해 몬테카를로 시뮬레이션을 수행하였으며, 이를 통해 정보공유의 유무와 구조가 시스템에 미치는 영향을 분석했다.

• International Journal of Aeronautical and Space Sciences
• /
• 제18권4호
• /
• pp.709-718
• /
• 2017

This paper proposes the guidance laws for an agile turn of air-to-air missiles during the initial boost phase. Optimal solution for the agile turn is obtained based on the optimal control theory with a simplified missile dynamic model. Angle-of-attack command generating methods for completion of agile turn are then proposed from the optimal solution. Collision triangle condition for non-maneuvering target is reviewed and implemented for update of terminal condition for the agile turn. The performance of the proposed method is compared with an existing homing guidance law and the minimum-time optimal solution through simulations under various initial engagement scenarios. Simulation results verify that transition to homing phase after boost phase with the proposed method is more effective than direct usage of the homing guidance law.