• Nuclear Engineering and Technology
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• 제49권2호
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• pp.395-403
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• 2017

An efficient evaluation method for the probability of a tornado missile strike without using the Monte Carlo method is proposed in this paper. A major part of the proposed probability evaluation is based on numerical results computed using an in-house code, Tornado-borne missile analysis code, which enables us to evaluate the liftoff and flight behaviors of unconstrained objects on the ground driven by a tornado. Using the Tornado-borne missile analysis code, we can obtain a stochastic correlation between local wind speed and flight distance of each object, and this stochastic correlation is used to evaluate the conditional strike probability, $Q_V(r)$, of a missile located at position r, where the local wind speed is V. In contrast, the annual exceedance probability of local wind speed, which can be computed using a tornado hazard analysis code, is used to derive the probability density function, p(V). Then, we finally obtain the annual probability of tornado missile strike on a structure with the convolutional integration of product of $Q_V(r)$ and p(V) over V. The evaluation method is applied to a simple problem to qualitatively confirm the validity, and to quantitatively verify the results for two extreme cases in which an object is located just in the vicinity of or far away from the structure.

• 한국항행학회논문지
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• 제22권2호
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• pp.57-63
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• 2018

항공기 발사용 유도무기는 자체점검시험(BIT; built in test) 뿐만 아니라 MIL-STD-1760표준을 준수하여 전원, 이산신호, MUX(multiplexer)통신 등 다양한 시험을 수행해야 시스템 안전성 및 신뢰성이 입증된다. 본 사례 연구 목적은 MIL-STD-1760E 기반 항공기-무장간 연동용 테스트 벤치 구축을 통하여 공대지 유도탄 개발 시 유도탄 전원인가부터 표적정보 입력, 전달정렬, 유도탄 분리 절차에 이르기까지 정의된 TIME LINE에 의거 유도탄 발사 시퀀스 구현 방안을 제시하기 위함이고, 추가적으로 오류삽입기능을 통해 비 활성탄에서 시험할 수 없는 항목까지 검증 범위를 극대화하는 참조 방안이 될 수 있다.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회/대한산업공학회 2005년도 춘계공동학술대회 발표논문
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• pp.1020-1025
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• 2005

The set covering(SC) problem has many practical application of modeling not only real world problems in civilian but also in military. In this paper we study optimal allocation model for maximizing utility of consolidating old fashioned and new air defense weapon system like Patriot missile and develop the new computational algorithm for the SC problem by using simulated annealing(SA) algorithm. This study examines three different methods: 1) simulated annealing(SA); 2) accelerated simulated annealing(ASA); and 3) selection by effectiveness degree(SED) with SA. The SED is adopted as an enhanced SA algorithm that the neighboring solutions could be generated only in possible optimal feasible region at the PERTURB function. Furthermore, we perform various experiments for both a reduced and an extended scale sized situations depending on the number of customers(protective objective), service(air defense), facilities(air defense artillery), threat, candidate locations, and azimuth angles of Patriot missile. Our experiment shows that the SED obtains the best results than others.

• 한국항공우주학회지
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• 제47권12호
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• pp.865-873
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• 2019

유도탄의 생존율을 향상시키기 위해서는 레이더에 의한 피탐성을 낮춰야 하는데 이는 레이더 반사 면적과 레이더에서 목표까지의 상대 거리의 함수로 주어진다. 또한 유도탄의 레이더 반사 면적은 레이더에서 방출되는 전자기파에 대한 목표물의 입사각에 의해 결정된다. 본 논문에서는 유도탄이 적절한 자세 제어 시스템을 갖추고 있다는 가정 하에 고고도에서 레이더에 의한 피탐성을 최소화하기 위한 유도탄의 자세를 조사한다. 레이더 반사 면적의 총합과 신호 대 잡음 비의 총합, 두 가지 다른 유형의 성능 비용을 고려한다. SQP 기법을 이용하여 단일 레이더 및 다수의 레이더에 대한 최적해를 산출한다.

• International Journal of Control, Automation, and Systems
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• 제5권4호
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• pp.397-409
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• 2007

In this paper, we propose a nonlinear guidance law for missiles against maneuvering targets. First, we derive the equations of motion described in the line-of-sight reference frame and then we define the equilibrium subspace of the nonlinear system to guarantee target interception within a finite time. Using Sontag's formula, we derive a nonlinear guidance law that always delivers the state to the equilibrium subspace. If the speed of the missile is greater than that of the target, the proposed law has global capturability in that, under any initial launch conditions, the missile can intercept the maneuvering target. The proposed law also minimizes the integral cost of the control energy and the weighted square of the state. The performance of the proposed law is compared with the augmented proportional navigation guidance law by means of numerical simulations of various initial conditions and target maneuvers.

• International Journal of Aeronautical and Space Sciences
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• 제18권1호
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• pp.129-137
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• 2017

When the micro-Doppler (MD) image of a ballistic missile is derived, the translational motion compensation (TMC) method is usually applied to the inverse synthetic aperture radar (ISAR) image, but yields poor results because of the micro-motion of the ballistic missile. This paper proposes an efficient TMC method to obtain a focused MD image of a ballistic missile engaged in complicated micro-motion. During range alignment, range profiles (RPs) are coarsely aligned by using the 1D entropy cost function of RPs as a mark, then the coarsely-aligned RPs are fine-aligned by using the minimum 2D entropy of the MD image. During phase adjustment, the gradient of the phase error is appropriately weighted and added to the previous phase error to further fine-tune the aligned RPs. In simulations using the point scatterer model and the measured data from the real missile model, the proposed method provided better image focus than the existing method.

• 한국항공우주학회지
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• 제30권7호
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• pp.29-35
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• 2002

접는 미사일 조종날개의 공력탄성학적 특성을 조사하였다. 접는 미사일 조종날개는 2차원 익형 모델로 가정하였다. 초음속 DPM을 이용하여 초음속 비정상 공기력을 계산하였으며, 최소 상태 변수 근사법을 이용하여 비정상 공기력을 근사화하였다. 선형 및 비선형 플러터 해석을 위해 근궤적법과 시간적분법을 사용하였다. 비선형 플러터 해석을 위해 전개부의 힌지는 비대칭 이선형 스프링으로 가정하였으며, 기술함수를 이용하여 선형화하였다. 플러터 해석으로부터, 비선형 파라미터가 공력탄성학적 특성에 미치는 영향을 조사하였다.

• 한국군사과학기술학회지
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• 제15권4호
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• pp.374-380
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• 2012

In guided missile systems, reducing terminal-position error is the primary objective of the inertial navigation system. As a seeker is used to sense and track a target, the critical function of the inertial navigation system is to provide the seeker with accurate missile attitude information and help the seeker to keep tracking a target continuously. As inertial sensor body and missile body alignment errors are taken into account, it is desirable to minimize the alignment errors between the missile seeker and the attitude of inertial navigation system. Among the alignment errors, this paper addresses the methods of measuring and compensating misalignment between inertial sensor body and housing frame and shows test results of several experiments.

• 한국군사과학기술학회지
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• 제22권4호
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• pp.536-544
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• 2019

During the assembly and function inspection of missile system, flight simulation process is required. In the conventional flight simulation check of missiles, an inertial navigation system simulator was used to transmit the navigation output data acquired in HILS. There are several disadvantages in terms of check configuration complexity and data synchronization when using the simulator. So we proposed a new flight simulation method that utilizes the nonvolatile built-in memory of the aviation control unit. The data processing procedure and operation procedure of the proposed method for type I and type II missiles are presented. And we analyzed the causes of the difference between proposed method result and the HILS result for type II missile. By comparing the results obtained by the experiments using the proposed method with the results of HILS, the validity of proposed method was confirmed.

• 한국군사과학기술학회지
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• 제26권2호
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• pp.171-178
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• 2023

PCM data is result of air-vehicle flight test, this data is distributed for each engineers to analyze its condition. Since line-of-sight between the air-vehicle and the ground receiver cannot always be secured, remote PCM data recording system was claimed to be required. In this paper multi-function PCM data recorder has been described. This PCM data recorder was intended to place on inside of flight object. It can record about two hours in 32 GB SD card with maximum 7 Mbps data rate. RS-422/485 and RJ-45 interface enhanced accessibility for users. 5 V and 1 A power consumption and 19.5 mm × 152.5 mm × 102.3 mm allow to connect with mobile PCM devices. It acquired more than 190-minutes data in 12-times flight test. Also, it achieved military standard environmental test MIL-STD-810G to prove its stability and solidness.