Showing papers on "Missile published in 2003"

Closed-form solutions of optimal guidance with terminal impact angle constraint

Abstract: Optimal guidance laws and their closed-form solutions for controlling the impact angle as well as terminal miss are investigated in this paper. Generalized formulation of optimal guidance laws for constant speed missiles with a higher order system dynamics can be represented by a linear combination of a step and a ramp acceleration response of the missile. In the case of lag-free system, optimal guidance command is linear time varying and, therefore, the entire missile states can be expressed by polynomial functions in terms of time-to-go. We also proposed practical and precise time-to-go calculation methods in consideration of curved missile trajectory, which can be applied for various impact angle controllers. Basic properties including error analyses for the optimal guidance law for lag-free system are shown by numerical examples.

Modeling and H/sub /spl infin// control for switched linear parameter-varying missile autopilot

Abstract: This paper presents a new method for designing a gain-scheduled missile autopilot. The nonlinear missile dynamics are modeled as a switched linear parameter-varying (SLPV) system, as is also common for many hybrid system models. A gain-scheduled autopilot for the SLPV system is then designed using a new synthesis technique that is based on a nonsmooth dissipation framework. The proposed algorithm extends previously published Lyapunov-based LPV approaches in three important ways: the SLPV system can provide a more accurate model of the missile dynamics; the nonsmooth Lyapunov function used in the synthesis is a more general class of Lyapunov functions; and the gridding technique typically used to solve the synthesis can be eliminated from the problem. As a result, the new approach yields a reliable gain-scheduled autopilot with better performance than the LPV controllers available in the literature.

A review of guidance laws applicable to unmanned underwater vehicles

Abstract: The main problem in bringing autonomy to any vehicle lies in the design of a suitable guidance law. For truly autonomous operation, the vehicle needs to have a reliable Navigation, Guidance and Control (NGC) system of which the guidance system is the key element that generates suitable trajectories to be followed. In this review paper, various guidance laws found in the literature and their relevance to autonomous underwater vehicles (AUVs) are discussed. Since existing guidance laws for underwater vehicles have emulated from tactical airborne missile systems, a number of approaches for the missile guidance systems are considered. Finally, potential guidance strategies for AUVs are proposed.

Flowfield Around Spike-Tipped Bodies for High Attack Angles at Mach 4.5

Abstract: The requirements for the design of a new short-range high-velocity missile are both the drag reduction and the correct information acquisition for the optoelectronic sensors embedded in the hemispherical nose. High anglesof attack must be studied to fulfill the maneuverability requirements of present and future missiles. A supersonic missile generates a bow shock around its blunt nose, which causes rather high surface pressure and temperature and, as a result, the development of high drag and damage of embedded sensors. The pressure and the temperature on the hemispherical nose surface can be substantially reduced if an oblique shock is generated by a forward-facing spike. Both the experiments and the computations are carried out to study the flowfield around three-dimensional blunt bodies equipped with forward-facing spikes for a large range of attack angles at a Mach number of 4.5. A blunt body, a classical disk-tip spike, a sphere-tip spike, and a biconical-tip spike are studied. The experiments involve high-pressure shock tunnel investigations using a shock tube facility. The differential interferometry technique is applied to visualize the flowfield around the different missile spike geometries. The differential interferogram pictures as well as surface pressure measurements are compared with numerical results. Numerical simulations based on steady-state three-dimensional Navier-Stokes computations are performed to predict the drag, the lift, and the pitching moment for the blunt body and for each spike-tipped missile. The computations allow one to bring out the advantages of each spike geometry in comparison to the blunt body.

Problem of precision missile guidance: LQR and H/sup /spl infin// control frameworks

Abstract: Addressed here is the precision missile guidance problem where the successful intercept criterion has been defined in terms of both minimizing the miss distance and controlling the missile body attitude with respect to the target at the terminal point. We show that the H/sup /spl infin// control theory, when suitably modified, provides an effective framework for the precision missile guidance problem. The existence of feedback controllers (guidance laws) is investigated for the case of finite horizon and non-zero initial conditions. Both state feedback and output feedback implementations are explored.

Inflatable and Rigidizable Wings for Unmanned Aerial Vehicles

Abstract: Recent shifts in tactical defense operations have led to a need for improved capabilities in Unmanned Aerial Vehicles (UAVs). Several vehicle types such as the Predator are currently operational, and numerous smaller specialized vehicles are under development. Many of the vehicles under development require the ability to stow their wings and control surfaces into very small volumes to permit gun launch or packaging into aircraft mounted aerial drop assemblies. One technology that has shown promise in achieving this goal is the inflatable wing. Inflatable wings have been demonstrated in many applications over the past five decades, including aircraft, UAVs, airships, and missile stabilization surfaces. Recent advancements in high strength fibers and rigidizable materials have enabled higher performance designs for modern application. The inclusion of “smart materials” has provided the opportunity to impart a multi-functional capability to inflatable wings. Such materials include electronictextiles, which provide the potential for the integration of numerous functions directly into the structure of the wing such as shape modification for control and morphing, power generation and storage, antennas, and sensing.

Optimal Guidance with Constraints on Impact Angle and Terminal Acceleration

Abstract: Numbers of impact angle guidance laws have been studied in order to satisfy the flight path angle constraint on each waypoint that unmanned aerial vehicles for reconnaissance should pass by, or to increase the warhead effect for anti-ship or anti-tank missiles. These guidance laws converge to a finite value as the missile approaches to the target so that sometimes maneuver acceleration can easily be saturated in real situation. The saturation of maneuver acceleration in terminal phase may cause large miss distance and impact angle error. In this paper, an optimal guidance law with the capacity of adjusting terminal maneuver acceleration is studied to control impact angle as well as miss distance. Constant speed missiles with the 1 order system lag are assumed for deriving closed-form state feedback guidance law. Since the proposed guidance law is able to nullify the maneuver acceleration at impact instant, not only it is robust to disturbances or uncertainties in terminal phase, but also the performances of terminal miss due to command saturation to prevent structural failure or flight instability is improved.

Optimal Fixed-Interval Integrated Guidance-Control Laws for Hit-to-Kill Missiles

Abstract: Due to their potential for reducing the weapon size and efficiency, design methods for realizing hitto-kill capabilities in missile systems are of significant research interest in the missile flight control community. As defined in this paper, hit-tokill capability requires the missile to consistently achieve point-mass miss distances less than half the minimum dimension of the target. It has been noted in the literature that the chief contributors to the miss distance in homing missiles are the seeker errors, autopilot lag, target maneuvers, and target state estimation lag. Guidance laws for ameliorating the effects of each of these miss distance components have been discussed in several recent publications. The present research addresses the hit-to-kill missile flight control problem by casting it as an integrated guidance-control problem. By including the complete dynamics of the missile, the integrated guidance-control formulation automatically compensates for the impact of the autopilot lag on the miss distance. The resulting finite-interval control problem is then solved using a transformation approach. Interception by a kinetic warhead is used as an example to illustrate the performance of the integrated guidance-control law.

Robust guidance for electro-optical missiles

Abstract: A robust guidance law is presented which renders zero miss distance (ZMD) against deterministically or randomly maneuvering targets for all missile parametric uncertainties. Since the resulting guidance controller is a phase-lead network, it is mainly suitable for systems characterized by moderate glint levels such as electro-optical missiles. The structured uncertainties in missile dynamics are modeled by interval transfer functions. It is first shown that for the nominal case, when the total missile transfer function is positive real, ZMD can be obtained. When uncertainties are considered, the problem becomes design of a guidance controller which renders a family of transfer functions positive real. A new algorithm for the design of such controllers is proposed. An example illustrating a typical design procedure for a nonlinear real-life missile model is given, showing the simplicity and effectiveness of the proposed robust guidance. The main conclusion of this work is that the newly developed guidance law performs well against highly maneuvering targets and may be a suitable alternative to optimal guidance laws in low-glint systems.

Design of optimal midcourse guidance sliding-mode control for missiles with TVC

Abstract: This work discusses a nonlinear midcourse missile controller with thrust vector control (TVC) inputs for the interception of a theater ballistic missile, including autopilot system and guidance system. First, a three degree-of-freedom (DOF) optimal midcourse guidance law is designed to minimize the control effort and the distance between the missile and the target. Then, converting the acceleration command from guidance law into attitude command, a quaternion-based sliding-mode attitude controller is proposed to track the attitude command and to cope with the effects from variations of missile's inertia, aerodynamic force, and wind gusts. The exponential stability of the overall system is thoroughly analyzed via Lyapunov stability theory. Extensive simulations are conducted to validate the effectiveness of the proposed guidance law and the associated TVC.

New Interceptor Guidance Law Integrating Time-Varying and Estimation-Delay Models

Abstract: The paper presents a synthesis of a new guidance law, derived using differential games concepts, for the interception of highly maneuvering targets. The synthesis is based on the integration of two recently demonstrated improvementfeatures:namely,theuseofa time-varying linearkinematicsgamemodelandthecompensationofthe inherent estimation delay of thetarget acceleration. The new guidance law is implemented in a genericyet realistic noise-corruptedthree-dimensionalnonlinearballisticmissiledefensescenariobyusingasuitablethree-dimensional estimator.Thetestagainstworst-casetargetmaneuversdemonstratesasignie cantimprovementcomparedto other known guidance laws indicating a potential breakthrough in interceptor guidance. I. Introduction H ISTORICALLY, the typical target of interceptor missiles has been a manned aircraft, against which the missile had substantial advantage in speed, maneuverability, and agility. Moreover, miss distances of a few meters, compatible with the lethal radius of the missile warhead, were considered admissible. Because of these facts, even a simple guidance law such as proportional navigation (PN) could guarantee the target destruction. The Gulf War introduced the tactical ballistic missile (TBM), able to carry nonconventional warheads, as a new type of target. Successful interception of a TBM, much less vulnerable than an aircraft, requires a very small miss distance or even a direct hit. Several ballistic missile defense systems are currently in development. Because of advances in technology, these systems (such as ARROW and PAC-3) succeeded to demonstrate, using conventionalguidance concepts, excellent homing accuracy against such nonmaneuvering targets. 1;2 Although known TBMs were not designed to maneuver because of their high reentry speed, they have a substantial maneuverability potential in the atmosphere. Moreover, this potential can be made applicable by a modest technical effort. The same is true for future high-speed antiship or cruise missiles.Paradoxically, the successful current development of ballistic missile defense systems can serve to motivate the future development of maneuverable antisurface missiles. Against such threats interceptor missiles will have only a marginal maneuverability advantage. Hence, the required small miss distances are not achievable by using conventional guidance laws even in a noise-free environment, as it was demonstrated by recent simulation studies. 3;4 Most missile guidance laws used at the present, including PN, were derived using a linear quadratic optimal control formulation assuming perfect information. 5 Such a formulation requires an assumption on the future evolution of the target maneuver. If this

Control of terminal engagement geometry using generalized vector explicit guidance

Abstract: This paper evaluates a new guidance law termed generalized vector explicit guidance (GENEX). This guidance law has the ability to simultaneously achieve design specifications on miss distance and final missile-target relative orientation. The latter specification may be used to enhance the performance of warheads whose effectiveness is influenced by the terminal encounter geometry. The GENEX guidance law is parameterized in terms of a design coefficient n which is specified by the user and which determines the degree of curvature (and hence control usage) in the trajectory. Feasibility of the GENEX guidance law was demonstrated by its application to a missile terminal homing scenario. Under conditions of ideal sensor information, and assuming a simplified single-lag missile response model, the guidance was shown to perform well against an air target performing evasive maneuvers. The specified zero aspect terminal encounter angle was achieved while simultaneously minimizing the miss distance.

Aircraft protection system and method

Abstract: According to one embodiment of the invention, a system for protecting aircraft includes a plurality of missile warning sensors and a turret mounted near the top of at least one support structure. Each missile warning sensor is operable to detect a missile and the turret is operable to emit a laser beam that is directed toward the missile to divert the missile from its intended flight pattern.

Sensitivity of Hydrocarbon Combustion Modeling for Hypersonic Missile Design

Abstract: Aspects relating to the aerodynamic and propulsive design and analysis of missile-class, waverider-based hypersonic vehicles are explored in this paper. A quasi-one-dimensional engine model, including the effects of fuel injection, mixing, chemical production rates, heat transfer, and viscous losses, is developed and utilized to assess the effects of finite rate, hydrocarbon chemistry on optimized missile configurations. Resultant optimized single-and double-engine missile designs are shown for changes in fuel mixing length, fuel mixing efficiency, fuel-injector location, and assumed fuel mass fraction. The effects of these different design conditions on the cruise range are explored, as well as perturbations around these design points for optimized vehicles. Missiles are optimized for steady-state trim conditions at the beginning of cruise flight using parallelized genetic algorithm optimization software developed for this study. All missile designs are assumed to reach cruising altitude and velocity through the use of an external rocket booster. The missile is geometrically constrained to fit within the 0.61 x 0.61 × 4.27 m box limits for a naval vertical launch tube and has a desired cruise range of 750 km at Mach 8. Results show that the optimized combustor designs were extremely sensitive to small design perturbations. Two engine configurations are shown to be more robust than single-engine models for engine design perturbations.

Autopilot design for agile missile with aerodynamic fin and side thruster

Abstract: This paper is concerned with a mixed control with aerodynamic fin and side thrusters applied to an agile missile using dynamic inversion and the Extended-Mean Assignment (EMA) control technique. The nonlinear dynamic inversion method with the weighting function allocates the desired control inputs (aerodynamic fin and side thrusters) to track a reference trajectory, and the EMA control technique guarantees the robustness for the uncertainties. The proposed schemes are validated by nonlinear simulations.

Numerical Investigation of Canard-Controlled Missile with Planar and Grid Fins

Abstract: Viscous computational fluid dynamic simulations were used to predict the aerodynamic coefficients and flowfield around a generic canard-controlled missile configuration in supersonic flow. Computations were performed at Mach 1.5 and 3.0, six angles of attack between 0 and 10 deg, with 0- and 10-deg canard deflection, and with planar and grid tail fins, for a total of 48 cases. Validation of the computed results was demonstrated by the very good agreement between the computed aerodynamic coefficients and those obtained from wind-tunnel measurements. Visualizations of the flowfield showed that the downwash off of the canards produced a low-pressure region on the starboard side of the missile that, in turn, produced an adverse side force. The pressure differential on the leeward fin produced by the interaction with the canard trailing vortices is primarily responsible for the adverse roll effect observed when planar fins are used. Grid tail fins improved the roll effectiveness of the canards at low supersonic speed. Flow visualizations from the simulations performed in this study help in the understanding of the flow physics and can lead to improved canard and tail fin designs for missiles and rockets.

Aircraft and missile forebody flow control device and method of controlling flow

Abstract: A forebody flow control system and more particularly to aircraft or missile flow control systems for enhanced maneuverability and stabilization at high angles of attack. The present invention further relates to a method of operating the flow control system. In one embodiment, the present invention includes a missile or aircraft comprising an afterbody and a forebody; at least one flow effector on the missile or aircraft forebody; at least one sensor having a signal associated therewith, the at least one sensor being positioned to detect flow separation on the missile or aircraft forebody; and a closed loop control system; wherein the closed loop control system is used for activating and deactivating the at least one flow effector based on at least in part the signal of the at least one sensor.

Missile detection and neutralization system

Abstract: The present invention is intended to provide a system for determining the precise launch point of ballistic missiles, and may additionally provide the capability of neutralizing said threats. The invention provides a mobile object information means configured to classify electromagnetic frequency activity within satellite and land based commercial and private broadcast and telecommunications spectra in a given geographical area, said means also configured to classify associated area weather normality and anomalies. The system includes a software algorithm configured to extract from said database, a missile launch in a given geographical zone by “tagging” an electromagnetic wave disturbance caused by the high intensity initial fuel burn of said missile launch. Additionally, the system is intended to affect the electrical functioning of a missile guidance system or warhead detonator by transmitting a precisely tuned frequency wave combination from a defensive missile borne frequency generator, or from a network of satellite or land based transmitters.

Containing Missile Proliferation: Strategic Technology, Security Regimes, and International Cooperation in Arms Control

Abstract: The proliferation of ballistic missiles that can deliver weapons of mass destruction halfway across the world is a matter of growing urgency and concern, as is the fate of agreements limiting the development of such deadly weapons. The Bush administration's scrapping of the ABM Treaty and pursuit of a huge National Missile Defense initiative are dramatic evidence of this concern. Yet there remains much uncertainty about the viability of missile defense. If defenses fall short, strong security regimes will be necessary to contain missile proliferation. Since 1987, more than thirty states have agreed to restrict their transfer of missiles and related technologies under the Missile Technology Control Regime (MTCR). During the MTCR's first decade, several regional powers were thwarted from advancing their missile ambitions. Subsequently, however, states such as North Korea, Iran, Pakistan, India, and Israel have tested medium-range missiles and others have expanded their missile arsenals. Dinshaw Mistry critically examines the successes and limitations of the MTCR, and suggests five practical ways to strengthen the regime. The author's exhaustive research offers new and detailed insights on the technology and politics of missile programs in Iran, Iraq, North Korea, Pakistan, India, Israel, Egypt, South Korea, Taiwan, and other countries. Mistry also shows how international cooperation, security regimes, and U.S. foreign policies of engagement and containment with these states can halt their missile programs. Mistry's book is the first comprehensive study of the MTCR and of international efforts to contain missile proliferation. Policymakers, scholars, and the general reader will find this book a valuable contribution to the subjects of arms control, ballistic missile proliferation, multilateral cooperation, and international security regimes. Dinshaw Mistry is assistant professor and director of Asian studies at the University of Cincinnati. He has written extensively on technology and politics, regional security, and international cooperation in The New York Times, Security Studies, Contemporary Security Policy, Asian Survey, Pacific Affairs, and other publications.

Missile defense system with dynamic trajectory adjustment

Abstract: A missile defense system includes a tracking station for monitoring the course and/or trajectory of an incoming missile. The incoming missile course and/or trajectory information is communicated to an intercept missile, whose course and/or trajectory are calculated based on the information of the incoming missile received from the tracking system and the intercept missile location received from, for example, a GPS system. The tracking system monitors the flight of the incoming missile to determine any changes to its course and/or trajectory, and communicates these changes to the intercept missile. The intercept missile adjusts its course and/or trajectory based on the updated information received from the tracking station to provide accurate and reliable intercept of the incoming missile.

On the need for integrated estimation/guidance design for hit-to-kill accuracy

Abstract: Separate designs of the estimator and the guidance law of an interceptor missile are, at best, suboptimal. This paper describes an innovative first step towards an integrated design. In order to cope with random target maneuvers, a set of feasible random maneuvers is selected. For each maneuver, a suitable estimator/guidance law combination is designed. The interception endgame is divided into two phases. During the initial phase, the actual target maneuver model is identified and a suitable estimator/guidance law combination is used in the terminal phase. The innovative feature of the new approach, tested by Monte Carlo simulations of a planar benchmark scenario, is the explicit use of the time-to-go information in the selection of the estimator/guidance law combination.

Averting 'the final failure' : John F. Kennedy and the secret Cuban Missile Crisis meetings

Abstract: Contents Foreword by Robert Dallek xi Preface: the JFK Cuban Missile Crisis Tapes xiii Listening to the JFK Tapes xvi Origins of the JFK Tapes xxi Opening the JFK Tapes xxiv The Historical Value of the JFK Tapes xxxvi Introduction: the Making of the Cuban Missile Crisis 1 The Cold War: JFK's Crucible 1 Nuclear Confrontation in Cuba 9 The Kennedy Paradox 32 Key Members of the Executive Committee of the National Security Council 41 The Secret Meetings of the Executive Committee of the National Security Council 57 Epilogue: The November Post-Crisis 403 Conclusion: Listening and Learning: Insights from the JFK ExComm Tapes 413 Appendix: The Published Cuban Missile Crisis Transcripts 427 Rounds One, Two and Beyond Bibliography 441 Index 451 Library of Congress Subject Headings for this publication: Cuban Missile Crisis, 1962, Kennedy, John F, (John Fitzgerald), 1917-1963, National Security Council (U, S, ) History 20th century, United States Foreign relations 1961-1963 Decision making, National security United States Decision making

Missile with odd symmetry tail fins

Abstract: A missile, either a powered missile or an unpowered projectile, includes a freely-rolling tail assembly having an odd number of fins. Having an odd number of fins may reduce oscillations caused by the rotation of the freely-rotating tail. This may make a more stable platform for a seeker, such as an uncooled focal point array or other imaging infrared (IIR) or millimeter wave radio frequency (MMW) seeker, in the body of the missile. Also, minimizing oscillation by using an odd number of fins may facilitate control of the missile.

Guided missile having a jettisoned protective cap

Abstract: A guided missile having a longitudinally extending airframe with a tip, a seeker head arranged in the tip and a window located in front of the seeker head for closing the airframe at the tip so as to protect the seeker head. A jettisonable protective cap consisting of at least two separable parts is attached to the airframe in front of the window for protection of the window.

Nonlinear rule-based controller for missile terminal guidance

Abstract: The design of a rule-based guidance law for homing missiles onto targets is presented. The stability of the missile-target dynamics is proven. Unlike conventional approaches that solve the Hamilton–Jacobi partial differential inequality associated with the missile guidance problem, the proposed guidance law is based on heuristic fuzzy rules. Furthermore, the proposed missile guidance control law guarantees that the missile can reach the impact region and destroy the target. An example is used to illustrate the application of the proposed design method.

Domestic Politics and Stakeholders in the North Korean Missile Development Program

Abstract: The Democratic People's Republic of Korea (hereafter \"the DPRK\" or \"North Korea\") and its missile development program have generated international concerns for several years. Most analysts agree that the DPRK missile program is a threat to security and stability in Northeast Asia and other regions, and North Korea's missile exports are well documented. The Bush administration has accused Pyongyang of being \"the world's number one merchant for ballistic missiles—open for business with anyone, no matter how maligned the buyer's intentions.\" Clearly North Korea's missile program has had an impact on international security; conversely, international variables, or changes in the international strategic environment, influence the DPRK in determining the program's scope and future development. However, the North Korean domestic political economy is also a determining factor. Missile development is technically difficult and very expensive, especially for relatively small countries like North Korea with backward or poorly performing economies. Missiles provide security benefits, at least in the short run, and arguably can provide economic benefits if we consider the potential foreign exchange earnings from exports. In the DPRK case, the missile development program has tremendous distributional consequences for North Korean society, which includes a number of \"stakeholders\" with different preferences for the future of the missile program. Given that Pyongyang's policymakers must consider both international and domestic politics when deciding missile development policy, predicting the future development path of the North Korean missile program is a complex task. Most analysis tends to focus on the international component of this problem, with little consideration for North Korean domestic politics and institutions. Some analysts might argue that domestic politics is irrelevant because the North Korean leadership is completely insulated from domestic pressures, or because all political and societal interests in North Korea converge on this issue. The DPRK is not a pluralistic polity; North Korean civil society is extraordinarily underdeveloped. Nevertheless, even the most authoritarian governments require a critical mass of supporters in order to remain in power and to continue programs that consume significant resources. This assumption raises key questions about the North Korean institutions and individuals that have particular

Method and system for detecting and determining successful interception of missiles

Abstract: A system for the detection and determination of the success of interception of incoming missiles, used in conjunction with a defense weapon system capable of identifying and tracking incoming missiles and interceptors. The system comprises at least one of a plurality of sensing units. Each sensing unit comprises: an optical sensor for detecting optical signals within a predetermined range; tracking means coupled to the optical sensor for tracking an intercepting missile or an incoming missile; processing means for processing optical input detected by the optical sensor and analyzing the optical input to identify an optical signature and determine detonation of interceptor or incoming missile; communicating means for communicating data between the sensing unit and the defense weapon system; and control means for controlling the tracking means, the processing means and the communicating data.

Turf test apparatus

Abstract: A drop test apparatus for determining the resiliency of playing surface comprising a missile for impacting the surface including a guide for providing substantially unrestricted free flight of the missile, a pair accelerometers carried by the missile for producing signals in response to impact with the surface, a converter adapted to receive the accelerometer signals, convert them into computer readable signals and a computer receiving the signals from the converter and producing a graph of the surface hardness.

Electro-optical missile plume detection

Abstract: Missile warning systems operating in the ultraviolet part of the spectrum have become a common part of the suite of self-defence systems of modern aircraft. These systems have a low false alarm rate and a detection range of several kilometers against man-portable surface-to-air missiles. The performance of the missile warning systems depends on several factors, including weather and threat type. This paper uses a generaic missile warning sensor and a recently developed model to predict missile plume UV radiance, to demonstrate the variability in detection range for a number of typical threats, weather types, aircraft speeds and warning system lay-outs. The variation in sensor performance present in the results shows that an assessment of the level of platform self-protection prior to each mission should be performed.