• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.450-455
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• 1993

Guidance commands for attitude controlled missiles inevitably take the form of attitude angle commands. On the other hand, many guidance laws compute the accelerations required to achieve their goals. Therefore some integrators must be in use for the attitude controlled missiles to implement the guidance laws. Naturally, the use of the integrator raises the problem of choosing a proper initial value. In this paper, we compute the integrator initial value which minimizes the terminal miss and show that if the total flight time of the mission is long enough, the "optimal" initial value becomes some multiple of the initial heading error or of the given impact angle to the target. We demonstrate the validity of the analysis by showing some linear and nonlinear simulation results.n results.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.359-362
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• 1996

The guidance system which uses the line-of-sight(LOS) rate to guide the missile towards its target has been used to the conventional differential game, such as the pursuer-evader game. Proportional navigation guidance and its derivatives have been shown to be an effective LOS rate guidance system. In this paper, we have used the genetic algorithm to construct the guidance system for the pursuer-evader type differential game. Also we have proposed the prediction model to obtain the informations about the intention of future actions of the pursuer and the evader.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 26-27 Oct. 1990
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• pp.469-474
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• 1990

The implementation of modern guidance law derived from optimal control theory requires accurate current states of target, for example, position, velocity and acceleration etc. But there is no sensors that measure the target states directly. So they are estimated from measurable data. For atmospheric missile engagement, direct application of the modern guidance laws may result In deterioration of Intercept performance because of poor observability associated with angles only-measurements by passive seeker and homing geometry. In this paper, a trajectory modulation method called "adaptive Intermittent maneuvers" is added to the modern guidance law, so the observability is enhanced and, consequently, improved the intercept performance. The estimation algorithm called "modified gain pseudo-measurement filter" is used for tracking filter. It is assumed that the passive seeker measure the angles between line of sight and Inertial frame. The Monte-Carlo simulation for realistic air-to-air Intercept scenario are conducted to demonstrate the effectiveness of intermittent maneuvers.ermittent maneuvers.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제19권3호
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• pp.253-270
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• 2015

Two major simultaneous attack strategies have been introduced, as one of cooperative attack of multiple missiles. One strategy is an undesignated time attack, in which the missiles communicate among themselves to synchronize the arrival times by reducing the mutual differences of times-to-go of multiple missiles during the homing. The other is a designated time attack, in which a common impact time is commanded to all members in advance, and thereafter each missile tries to home on the target on time independently. For this individual homing, Impact-Time-Control Guidance (ITCG) law is required. After introducing cooperative proportional navigation (CPN) for the first strategy, this article presents a new closed-form ITCG guidance solution for the second strategy. It is based on the linear formulation, employing base trajectories driven by PNG with various navigation constants. Nonlinear simulation of several engagement situations demonstrates the performance and feasibility of the proposed ITCG law.

• 제어로봇시스템학회논문지
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• 제9권6호
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• pp.478-488
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• 2003

A guidance scheme that is suitable for controlling the aircraft flight path is proposed. The concept of miss distance which is commonly used in the missile guidance laws, and Lyapunov stability theorem are effectively combined to obtain the aircraft's trajectory-tracking guidance law. Guidance commands are given in terms of speed and flight path angles, but they perfectly reflect any position and velocity errors between real aircraft trajectory and reference one. The proposed guidance law is easily integrated into the existing flight control system. The new guidance law was extensively tested with various mission scenarios and the fully nonlinear 6-DOF aircraft model. Furthermore, the new guidance law was compared with previous guidance schemes in nonlinear simulation. Results from the numerical simulation show that the proposed guidance law yields better performance than previous ones.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1988년도 한국자동제어학술회의논문집(국내학술편); 한국전력공사연수원, 서울; 21-22 Oct. 1988
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• pp.597-602
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• 1988

In this paper, we consider conventional and modified proportional navigation guidance(PNG) laws for a random maneuvering target. By means of Lyapunov function approach, we show that an ideal missile guided by the conventional PNG law can always intercept a random maneuvering target if some specified initial conditions are satisfied and the navigation constant is chosen sufficiently high. In addition, we propose a modified PNG law. At the final phase of pursuit, the proposed guidance law has a better acceleration profile than the conventional PNG law.

• 한국항공우주학회지
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• 제30권5호
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• pp.41-47
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• 2002

본 논문에서는 일반항공기나 무인항공기의 자동착륙에 적용할 수 있는 착륙 유도 법칙을 제안하고 기존의 일반적인 착륙 과정과의 비교를 통하여 성능을 확인하였다. 착륙 유도법칙은 미사일 요격에서 사용되는 Miss distance 개념과 Lyapunov 안정성 이론에 근거하여 궤환 형태의 속도 및 비행 경로각 명령을 생성할 수 있도록 구성하였다. 기존 문헌에 제시된 항공기의 자동착륙 시뮬레이션을 이용하여 착륙 접근 및 착지 기동 과정을 모사하였다. 착륙 접근의 제U 목적인 강하로 이탈 거리 제거와, 착지 기동시 제어 목적인 고도 제어의 관점에서 새로이 제안하고 있는 착륙 유도 법칙은 기존 방법에 대등 또는 우수한 결과를 얻을 수 있었다. 기준 궤적의 설정에 따라 다양한 비행 궤적 추종이 가능하므로 향후 무인기의 자동 착륙이나 기동 비행의 설계시 적용할 수 있을 것이다.

• Journal of Electrical Engineering and Technology
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• 제8권1호
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• pp.190-196
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• 2013

This paper proposes a new guidance law, which considers the Field of View (FOV) of the seeker when a missile has a strapdown seeker mounted instead of a gimbal seeker. When a strapdown seeker, which has a narrow FOV, is used for tracking a target, the FOV of the seeker is an important consideration for guidance performance metrics such as miss distance. We propose a new guidance law called hybrid guidance (HG) to address the shortcomings of conventional guidance laws such as proportional navigation guidance (PNG), which cannot maintain lock-on conditions against high speed targets due to the narrow FOV of the strapdown seeker. The aim of the HG law is to null miss distance and to maintain the look angle within the FOV of the strapdown seeker. In order to achieve this goal, we combine two guidance laws in the HG law. One is a PNG law to null the LOS rate, and the other is a sliding mode guidance (SMG) law derived to keep the look angle within the FOV by employing a Lyapunov-like function with a sliding mode control methodology. We also propose a method to switch these two guidance laws at certain look angles for better guidance performance.

• 한국항공우주학회지
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• 제38권3호
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• pp.221-227
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• 2010

일반적인 전술유도탄에서 표적획득 센서로 사용되는 김발형 탐색기(Gimballed Seeker) 는 탐색기의 표적획득부가 유도탄의 동체운동과는 독립적으로 관성좌표계 상에서 표적을 지향하게 하여 비례항법 유도명령 생성에 필요한 유도탄/표적간의 시선 각속도 정보를 직접 제공한다. 반면 최근에는 탐색기 전체가 유도탄 동체에 고정됨으로써 정비보수 용이, 고장수리 감소, 단가감소 측면 등에서 유리한 동체고정 탐색기(Strapdown Seeker)에 대한 연구가 부분적으로 수행되고 있다. 그런데 동체고정 탐색기에서는 비례항법에 필요한 시선각속도가 직접주어지지 않고 탐색기 영상 평면에 맺힌 표적영상으로부터 유도명령생성에 필요한 정보를 추출하여야 한다. 본 연구에서는 먼저 스트랩다운 탐색기로부터 주어지는 표적정보를 바탕으로 언센티드 칼만필터(Unscented Kalman Filter, UKF)를 적용하여 유도탄과 표적간의 상대운동을 추정한다. 추정된 상대운동 정보를 이용하여 유도명령을 생성하고 유도탄과 표적간의 조우운동을 시뮬레이션을 통하여 검증하였다.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제19권3호
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• pp.271-287
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• 2015

In this article, a more generalized form of the impact time and angle control guidance law is proposed based on the linear quadratic optimal control methodology. For the purpose on controlling an additional constraint such as the impact time, we introduce an additional state variable that is defined to be the jerk (acceleration rate). Additionally, in order to provide an additional degree of freedom in choosing the guidance gains, the performance index that minimizes the control energy weighted by an arbitrary order of time-to-go is considered in this work. First, the generalized form of the impact angle control guidance law with an additional term which is used for the impact time control is derived. And then, we also determine the additional term in order to achieve the desired impact time. Through numbers of numerical simulations, we investigate the superiority of the proposed guidance law compared to previous guidance laws. In addition, a salvo attack scenario with multiple missile systems is also demonstrated.