좁은 화각을 갖는 스트랩다운 탐색기를 위한 유도기법

학위논문 (박사)-- 서울대학교 대학원 : 전기·컴퓨터공학부, 2013. 8. 최진영.New guidance laws are proposed to solve the problem of when a missile is equipped with a strapdown seeker instead of a gimbaled seeker. The strapdown seeker has advantages of relatively simple implementation compared to a gimbaled seeker, and it can eliminate frictional cross-coupling significantly save on costs. There have been many studies to enable guided missiles to use strapdown seekers, but they have several weaknesses, such as measurement error caused by scale factor error, radome errors, glint noise, narrow field-of-view (FOV), and so on. Among these weak points, focus is centered on the narrow FOV of the strapdown seeker. A hybrid guidance (HG) law is proposed to maintain the lock-on condition in spite of the narrow FOV of the strapdown seeker. The proposed HG law consists of two guidance phases, which assume operation at a switching boundary. In the first phase, the proportional navigation guidance (PNG) law is applied during the time when the look angle is inside the switching boundary. For the second phase, when the look angle is outside the switching boundary, a new guidance law is derived to keep the look angle within the FOV by employing a Lyapunov-like function based on sliding-mode control methodology. The appropriate determination of the switching boundary is an important issue. The idea behind selecting the switching boundary is to use the PNG law as much as possible, and to make the missile stay in the lock-on condition. A lock-on guidance (LOG) is proposed as another approach to solve the problem of narrow FOV, based on the concept of the pursuit guidance (PG) law. In order to derive the LOG law, we use a Lyapunov-like function based on the sliding-mode control methodology. An advantage of the LOG law is that a missile guided by the LOG law can intercept a target with a very narrow FOV of the strapdown seeker. Because such a seeker often has to be implemented for more accurate measurements, this kind of guidance law is needed to prepare for such a situation. The LOG law is simple and has good performance against a target with high speed.Abstract i Contents iii List of Figures vi List of Tables x Chapter 1. Introduction 1 1.1 Background and Motivations 1 1.2 Contents of the Research 6 Chapter 2. Preliminary Survey 10 2.1 Survey on Guidance Laws 10 2.1.1 Classical Guidance Laws 10 2.1.1.1 Pursuit Guidance Law 12 2.1.1.2 Constant Bearing Course Guidance Law 13 2.1.1.3 Line-of-Sight Guidance Law 13 2.1.1.4 Proportional Navigation Guidance Law 16 2.1.2 Modern Guidance Laws 23 2.1.2.1 Optimal-Control-Based Guidance Law 24 2.1.2.2 Predictive Guidance Law 27 2.1.2.3 Game-Theory-Based Guidance Law 30 2.1.2.4 Sliding-Mode-Control-Based Guidance Law 31 2.1.3 Summary 32 2.2 Survey on Missile Seekers 33 2.2.1 Gimbal Seeker 34 2.2.2 Strapdown Seeker 35 2.2.3 Summary 36 2.3 Remarks and Discussions 37 Chapter 3. The Proposed Guidance Laws 40 3.1 Hybrid Guidance Law 40 3.1.1 Problem Statement 41 3.1.2 The Overall Scheme 46 3.1.3 Guidance Law for the First Phase 48 3.1.4 Guidance Law for the Second Phase 48 3.1.5 Switching Boundary Estimation 50 3.2 Lock-on Guidance Law 56 3.2.1 Problem Statement 57 3.2.2 The Overall Scheme 62 3.2.3 Derivation 64 Chapter 4. Simulation Results 70 4.1 Hybrid Guidance Law 70 4.1.1 Non-maneuvering Target 70 4.1.2 Maneuvering Target 76 4.2 Lock-on Guidance Law 85 4.1.1 Non-maneuvering Target 85 4.1.2 Maneuvering Target 96 4.3 Comparison of Hybrid Guidance Law and Lock-on Guidance Law 105 Chapter 5. Conclusions 109 5.1 Concluding Remarks 109 5.2 Further Study 111 Bibliography 112 국문초록 123Docto

Current Trends in Tactical Missile Guidance

The problem of tactical missile guidance is very challenging and has been treated using several basic metlfodologies in the past four decades. Major techniques can be grouped underclassical guidance laws, modern guidance laws, l'aws for manoeuvring targets, predictive guidance for endgame scenario, and guidance laws based on intelligent control methods. Each technique has some advantages and disadvantages while implementing in a practical system. Guidance law selection is dictated by nature of flight profile like boost, midcourse, terminal homing, etc, and also miss-distance and a single-shot kill probability. This paper presents a brief survey of the existing techniques and current trends in tactical missile guidance

Sensors, measurement fusion and missile trajectory optimisation

When considering advances in “smart” weapons it is clear that air-launched systems have adopted an integrated approach to meet rigorous requirements, whereas air-defence systems have not. The demands on sensors, state observation, missile guidance, and simulation for air-defence is the subject of this research. Historical reviews for each topic, justification of favoured techniques and algorithms are provided, using a nomenclature developed to unify these disciplines. Sensors selected for their enduring impact on future systems are described and simulation models provided. Complex internal systems are reduced to simpler models capable of replicating dominant features, particularly those that adversely effect state observers. Of the state observer architectures considered, a distributed system comprising ground based target and own-missile tracking, data up-link, and on-board missile measurement and track fusion is the natural choice for air-defence. An IMM is used to process radar measurements, combining the estimates from filters with different target dynamics. The remote missile state observer combines up-linked target tracks and missile plots with IMU and seeker data to provide optimal guidance information. The performance of traditional PN and CLOS missile guidance is the basis against which on-line trajectory optimisation is judged. Enhanced guidance laws are presented that demand more from the state observers, stressing the importance of time-to-go and transport delays in strap-down systems employing staring array technology. Algorithms for solving the guidance twopoint boundary value problems created from the missile state observer output using gradient projection in function space are presented. A simulation integrating these aspects was developed whose infrastructure, capable of supporting any dynamical model, is described in the air-defence context. MBDA have extended this work creating the Aircraft and Missile Integration Simulation (AMIS) for integrating different launchers and missiles. The maturity of the AMIS makes it a tool for developing pre-launch algorithms for modern air-launched missiles from modern military aircraft.EThOS - Electronic Theses Online ServiceGBUnited Kingdo