Showing papers on "Missile published in 2011"

Optimal Cooperative Pursuit and Evasion Strategies Against a Homing Missile

Abstract: Optimal-control-based cooperative evasion and pursuit strategies are derived for an aircraft and its defending missile. The aircraft-defending missile team cooperates in actively protecting the aircraft from a homing missile. The cooperative strategies are derived assuming that the incoming homing missile is using a known linear guidance law. Linearized kinematics, arbitrary-order linear adversaries' dynamics, and perfect information are also assumed. Specific limiting cases are analyzed in which the attacking missile uses proportional navigation, augmented proportional navigation, or optimal guidance. The optimal one-on-one, noncooperative, aircraft evasion strategies from a missile using such guidance laws are also derived. For adversaries with first-order dynamics it is shown that depending on the initial conditions, and in contrast to the optimal one-on-one evasion strategy, the optimal cooperative target maneuver is either constant or arbitrary. These types of maneuvers are also the optimal ones for the defender missile. Simulation results confirm the usefulness and advantages of cooperation. Specifically, it is shown how the target can lure in the attacker, allowing its defender to intercept the attacking missile even in scenarios in which the defender's maneuverability is at a disadvantage compared with the attacking missile.

Cooperative Differential Games Strategies for Active Aircraft Protection from a Homing Missile

Abstract: Cooperative pursuit―evasion strategies are derived for a team composed of two agents. The specific problem of interest is that of protecting a target aircraft from a homing missile. The target aircraft performs evasive maneuvers and launches a defending missile to intercept the homing missile. The problem is analyzed using a linear quadratic differential game formulation for arbitrary-order linear players' dynamics in the continuous and discrete domains. Perfect information is assumed. The analytic continuous and numeric discrete solutions are presented for zero-lag adversaries' dynamics. The solution of the game provides 1) the optimal cooperative evasion strategy for the target aircraft, 2) the optimal cooperative pursuit strategy for the defending missile, and 3) the optimal strategy of the homing missile for pursuing the target aircraft and for evading the defender missile. The obtained guidance laws are dependent on the zero-effort miss distances of two pursuer―evader pairs: homing missile with target aircraft and defender missile with homing missile. Conditions for the existence of a saddle-point solution are derived and the navigation gains are analyzed for various limiting cases. Nonlinear two-dimensional simulation results are used to validate the theoretical analysis. The advantages of cooperation are shown. Compared with a conventional one-on-one guidance law, cooperation significantly reduces the maneuverability requirements from the defending missile.

Back-stepping sliding mode control for missile systems based on an extended state observer

Abstract: A novel approach combining the sliding mode control and extended state observer (ESO) is proposed for attitude control of a missile model which is non-linear in aerodynamics. Combining the back-stepping technique, the corresponding sliding mode controller is designed to guarantee the state variables of the closed-loop system to converge to the reference state with the help of the ESO by estimating the unknown variable. Also, simulation results are presented to illustrate the effectiveness of the control strategy.

Intercept-Angle Guidance

Abstract: interest is aerial interception between a missile and a maneuvering target. The guidance concept is applicable in all aerial interception geometries: namely, head-on, tail-chase, and the novel head-pursuit. Analytical conditions for existence of these different engagement geometries are derived. The guidance concept is implemented using the sliding-modeapproach. Thecommonassumption of flight alonganinitial collisiontriangle isnottaken,andthusthe guidance law is applicable for both midcourse and endgame guidance. The application in the different engagement geometries is studied via simulation. It is shown that the head-on scenario allows the smallest range of intercept angles.Italsoplacesthemostseveremaneuverabilityrequirementsontheinterceptor.Thus,insomecases,tail-chase or head-pursuit engagements should be considered instead. The choice between the two is dependent on the adversary’s speed ratio; for tail-chase, the interceptor must have a speed advantage over its target, while for headpursuit, it must have a speed disadvantage.

Line-of-Sight Interceptor Guidance for Defending an Aircraft

Abstract: = missile evasive maneuver normal to defendermissile line of sight amp = missile evasive maneuver component normal to target-missile line of sight at, ad, am = target, defender, and missile lateral accelerations, respectively at max, ad max, am max = target, defender, and missile maximum lateral accelerations, respectively atplos, adplos, amplos = target, defender, and missile accelerations normal to the line of sight, respectively Rd, Rm, Rdm = target-defender, target-missile, and defendermissile closing ranges, respectively tf = defender-missile interception time vt, vd, vm = target, defender, and missile speeds, respectively vtlos, vdlos, vmlos = target, defender, and missile speeds along the line of sight, respectively vtplos, vdplos, vmplos

Guidance of Unmanned Aerial Vehicles

Abstract: Basics of Guidance Guidance Process Missile Guidance Guidance of Cruise Missiles and UAVs Representation of Motion Line-of-Sight Longitudinal and Lateral Motions Control of Lateral Motion Parallel Navigation Proportional Navigation: Planar Engagement Proportional Navigation: Three-Dimensional Engagement Augmented Proportional Navigation Proportional Navigation as a Control Problem Augmented Proportional Navigation as a Control Problem When Is the PN law Optimal? Control of Longitudinal and Lateral Motions Guidance Correction Controls Lyapunov Approach to Control Law Design Bellman-Lyapunov Approach: Optimal Guidance Parameters Modified Linear Planar Model of Engagement General Planar Case Three-Dimensional Engagement Model Generalized Guidance Laws Modifies Generalized Guidance Laws Examples Analysis of Proportional Navigation Guided Systems in Time Domain Inertialess PN Guidance System Method of Adjoints Analysis of Proportional Navigation Guided Systems in the Frequency Domain Adjoint Method: Generalized Model Frequency Domain Analysis Steady-State Miss Analysis Weave Maneuver Analysis Example Frequency Analysis and Miss Step Response Bounded Input-Bounded Output Stability Frequency Response of the Generalized Guidance Model Design of Guidance Laws Implementing Parallel Navigation: Frequency-Domain Approach Neoclassical Missile Guidance Pseudoclassical Missile Guidance Example Systems Guidance Law Performance Analysis Under Stochastic Inputs Brief Discussion of Stochastic Processes Random Target Maneuvers Analysis of Influence of Noises on Miss Distance Effect of Random Target Maneuvers on Miss Distance Computational Aspects Examples Filtering Guidance of UAVs Basic Guidance Laws and Vision-Based Navigation Generalized Guidance Laws for UAVs Guidance of a Swarm of UAVs Obstacle Avoidance Algorithms Testing Guidance Laws Performance Forces Acting on Unmanned Aerial Vehicles Reference Systems and Transformations Unmanned Aerial Vehicles Dynamics Autopilot and Actuator Model Seeker Model Filtering and Estimation Kappa Guidance Lambert Guidance Simulation Models of Unmanned Aerial Vehicles Integrated Design Integrated Guidance and Control Model Synthesis of Control Laws Integration and Decomposition Guidance Laws for Boost-Phase Interceptors Launched from UAVs Kill Vehicles for Boost-Phase Defense Development of the Missile Model and Selection of Guidance Law Parameters Endgame Requirements and the Comparative Analysis of Efficiency of Guidance Laws Advanced Guidance Laws Applied to Boost Stage Interceptor's Performance With Axial Control Comparative Analysis with Lambert Guidance Appendices

Network-based H ∞ output tracking control for systems with time-varying bounded delay

Abstract: This paper concerns with the network-based H ∞ output tracking of STT missiles. Based on decentralized control theory, the missile model is divided into three subsystems, and decentralized H ∞ output tracking controller is proposed for system with time varying delay. The network induced delay is assumed to have both the upper bound and the lower bound, which is more general compared with only considering the upper bound. The linear matrix inequality (LMI)-based procedure is adopted to design a state-feedback decentralized controller, which guarantees that the output of close-loop system tracks the output of a given reference model well in H ∞ sense. The controller is used on a STT missile, and the simulation result shows the usefulness and effectiveness of the proposed control approach.

Suboptimal Midcourse Guidance of Interceptors for High-Speed Targets with Alignment Angle Constraint

Abstract: Using the recently developed computationally efficient model predictive static programming and a closely related model predictive spread control concept, two nonlinear suboptimal midcourse guidance laws are presented in this paper for interceptors engaging against incoming high-speed ballistic missiles. The guidance laws are primarily based on nonlinear optimal control theory, and hence imbed effective trajectory optimization concepts into the guidance laws. Apart from being energy efficient by minimizing the control usage throughout the trajectory (minimum control usage leads to minimum turning, and hence leads to minimum induced drag), both of these laws enforce desired alignment constraints in both elevation and azimuth in a hard-constraint sense. This good alignment during midcourse is expected to enhance the effectiveness of the terminal guidance substantially. Both point mass as well as six-degree-of-freedom simulation results (with a realistic inner-loop autopilot based on dynamic inversion) are presented in this paper, which clearly shows the effectiveness of the proposed guidance laws. It has also been observed that, even with different perturbations of missile parameters, the performance of guidance is satisfactory. A comparison study, with the vector explicit guidance scheme proposed earlier in the literature, also shows that the newly proposed model-predictive-static-programming-based and model-predictive-spread-control-based guidance schemes lead to lesser lateral acceleration demand and lesser velocity loss during engagement.

MISSILE DATCOM User's Manual - 2011 Revision

Abstract: : This report is a User's Manual for the 2011 Revision of the Missile Datcom computer program. It supersedes AFRL-RB-WP-TR-2009-3015. In missile preliminary design it is necessary to quickly and economically estimate the aerodynamics of a wide variety of missile configuration designs. Since the ultimate shape and aerodynamic performance are so dependent upon the subsystems utilized, such as payload size, propulsion system selection and launch mechanism, the designer must be capable of predicting a wide variety of configurations accurately. The fundamental purpose of Missile Datcom is to provide an aerodynamic design tool which has the predictive accuracy suitable for preliminary design, and the capability for the user to easily substitute methods to fit specific applications.

Adaptive dynamic surface control for integrated missile guidance and autopilot

Abstract: Integrated guidance and control for homing missiles utilizing adaptive dynamic surface control approach is considered based on the three channels independence design idea. A time-varying integrated guidance and control model with unmatched uncertainties is first formulated for the pitch channel, and an adaptive dynamic surface control algorithm is further developed to deal with these unmatched uncertainties. It is proved that the proposed feedback controller can ensure not only the accuracy of target interception, but also the stability of the missile dynamics. Then, the same control approach is further applied to the control design of the yaw and roll channels. The 6-degree-of-freedom (6-DOF) nonlinear missile simulation results demonstrate the feasibility and advantage of the proposed integrated guidance and control design scheme.

Method of controlling aircraft, missiles, munitions and ground vehicles with plasma actuators

Abstract: A method of controlling an aircraft, missile, munition or ground vehicle with plasma actuators, and more particularly of controlling fluid flow across their surfaces or other surfaces which would benefit from such a method, includes the design of an aerodynamic plasma actuator for the purpose of controlling airflow separation over a control surface of a aircraft, missile, or a ground vehicle, and a method of determining a modulation frequency for the plasma actuator for the purpose of fluid flow control over these vehicles. Various embodiments provide steps to increase the efficiency of aircraft, missiles, munitions and ground vehicles. The method of flow control reduces the power requirements of the aircraft, missile, munition and or ground vehicle. These methods also provide alternative aerodynamic control using low-power hingeless plasma actuator devices.

Integrated guidance and control based on backstepping and input-to-state stability

Abstract: This paper presents an approach of integrated guidance and control (IGC) design for interception of maneuvering targets (evaders). An IGC model with uncertainties in the pitch plane is formulated, and the IGC approach is developed via backstepping scheme. Theoretical analysis is shown that the design approach makes the line-of-sight (LOS) rate be input-to-state stable (ISS) with respect to target maneuvers and missile model uncertainties, and the stability of the missile dynamics can be guaranteed as well. The numerical simulation confirms the effectiveness of the proposed design approach.

Sight Line Rate Estimation in Missile Seeker Using Disturbance Observer-Based Technique

Abstract: Filtering of base motion disturbance from the sight line rate is necessary for homing guidance of missiles. The present work proposes using a noninvasive seeker filter based on the disturbance observer concept to extract the target sight line rate signal from the raw signal corrupted with base motion disturbance. It is shown that the disturbance observer-based filter in favorable (nominal) condition can totally eliminate the platform motion from the raw sight line rate signal. The performance of the filter for off-nominal condition is also derived and exemplified. Simulation results demonstrate improved performance of the proposed filter compared to previously reported schemes.

System for protection against missiles

Abstract: Multiple embodiments of a system are disclosed for defeating enemy missiles and rockets by the use of a non-lethal cloud of pellets that collide with the missile a certain distance away from the target causing premature detonation of the missile, and/or possible severe damage to the missile, and/or deflection of the missile, and/or a deformation to the ogive cones to cause a short in the fuze circuit, and/or deposition of conductive material to cause a short in the fuze circuit.

Minimum Energy Guidance for Aerodynamically Controlled Missiles

Abstract: This paper examines the problem of guiding a missile to a target using minimal energy. First, an optimal controller is developed for a missile that has arbitrary control over its acceleration vector. Next, an optimal controller is sought for a missile that has a directional control constraint, which is intended to model the actual constraint present in aerodynamically controlled missiles. The optimal guidance law is shown to have a very convenient form that is directly related to the optimal guidance law without the control constraint. Simulation results are conducted to completely characterize the new guidance law.

Capture Region of a GIPN Guidance Law for Missile and Target with Bounded Maneuverability

Abstract: In this paper, a novel method is used to analyze the capture area of three-dimensional general ideal proportional navigation (GIPN) guidance laws. Using a line-of-sight (LOS) fixed natural coordinate and three modified polar variables (MPVs), the expression of relative dynamics between target and missile becomes simple, and no trigonometric functions are involved, which makes possible the analysis of the capture region when both target and missile are subject to bounded maneuverability. It can be shown that the determination of the desired capture area requires only the first two of the MPVs no matter if the maneuverability of missile and target are bounded or not. For the case of unbounded missile acceleration and known target acceleration, the capture region can be found analytically, while for the other cases, the capture region can be obtained graphically in a two-dimensional phase plane. The boundaries of these capture regions are characterized by the stable and unstable manifolds of related equilibrium points, which can only be determined numerically in general at this moment. The results of this work indicate that knowing the target acceleration and utilizing larger navigation coefficients increase the area of the capture region, which agrees with known results in literature.

Proxy-Based Sliding Mode Stabilization of a Two-Axis Gimbaled Platform

Abstract: Nowadays, high portion of tactical missiles use gimbaled seekers. For accurate target tracking, the platform where the gimbal is mounted must be stabilized with respect to the motion of the missile body. Line of sight stabilization is critical for fast and precise tracking and alignment. Although conventional PID framework solves many stabilization problems, it is reported that many PID feedback loops are poorly tuned. In this paper, a recently introduced approach, proxy-based sliding mode control to a line-of-sight stabilization of two-axis gimbal system, is implemented. The tracking performance and disturbance rejection capability of the proxy- based sliding mode control is compared with that of conventional PID control. Simulation and experimental results both indicate clear superiority of the proxy-based sliding control performance.

Anti‐ship missile defense for a naval task group

Abstract: In this study, we present a new formulation for the air defense problem of warships in a naval task group and propose a solution method. We define the missile allocation problem (MAP) as the optimal allocation of a set of surface-to-air missiles (SAMs) of a naval task group to a set of attacking air targets. MAP is a new treatment of an emerging problem fostered by the rapid increase in the capabilities of anti-ship missiles (ASMs), the different levels of air defense capabilities of the warships against the ASM threat, and new technology that enables a fully coordinated and collective defense. In addition to allocating SAMs to ASMs, MAP also schedules launching of SAM rounds according to shoot-look-shoot engagement policy or its variations, considering multiple SAM systems and ASM types. MAP can be used for air defense planning under a given scenario. As thorough scenario analysis would require repetitive use of MAP, we propose efficient heuristic procedures for solving the problem. © 2011 Wiley Periodicals, Inc. Naval Research Logistics, 2011

Time-Delay Control for Integrated Missile Guidance and Control

Abstract: In this paper, integrated missile guidance and control systems using time-delay control (TDC) are developed. The next generation missile requires that an interceptor hits the target, maneuvering with small miss-distances, and has lower weight to reduce costs. This is possible if the synergism existing between the guidance and control subsystems is exploited by the integrated controller. The TDC law is a robust control technique for nonlinear systems, and it has a very simple structure. The feature of TDC is to directly estimate the unknown dynamics and the unexpected disturbance using one-step time-delay. To investigate the performance of the integrated controller, numerical simulations are performed as the maneuver of the target. The results show that the integrated guidance and control system has a good performance.

A Crude Threat: The Limits of an Iranian Missile Campaign against Saudi Arabian Oil

Abstract: The United States and its Persian Gulf allies have been increasingly concerned with the growing size and complexity of Iran's ballistic missile programs. At a time when the United States and its allies remain locked in a standoff with Iran over the latter's nuclear program, states around the Persian Gulf fear that Iran would retaliate for an attack on its nuclear program by launching missiles at regional oil installations and other strategic targets. An examination of the threat posed by Iran's missiles to Saudi Arabian oil installations, based on an assessment of Iran's missile capabilities, a detailed analysis of Saudi Arabian oil infrastructure, and a simulated missile campaign against the network using known Iranian weapons, finds no evidence of a significant Iranian missile threat to Saudi infrastructure. These findings cast doubt on one aspect of the Iranian threat to Persian Gulf oil while offering an analytic framework for understanding developments in the Iranian missile arsenal and the vulnerability of oil infrastructure to conventional attack.

Practical Stochastic Optimal Guidance Law for Bounded Acceleration Missiles

Abstract: The purpose of this paper is to develop an optimal guidance law that takes into account both the missile acceleration limit and a maximum value allowed for the guidance gain. The maximum value of the guidance gain is dictated mainly by the possible coupling between the missile body motions and the measurement of the inertial target line-of-sight angle rate. The tools for this work are the linear quadratic stochastic Gaussian optimal control theory coupled with the use of random-input describing functions. Although the use of the random-input describing function introduces an approximation in the work, it has been shown in the past that the use of random-input describing functions in miss distance calculations results in good approximations for the predicted miss distance. The paper includes the derivation of the optimal guidance law that accounts for both the missile acceleration limit and the constraint on the guidance gain and a simple one-dimensional Monte Carlo simulation to examine the performance of the guidance law.

Kill Vehicle Guidance and Control Sizing For Boost-Phase Intercept

Abstract: This paper addresses some of the guidance and control issues involved in enabling an air-launched interceptor carrying a highly maneuverable kinetic kill vehicle to perform an exoatmospheric intercept of a boosting threat missile capable of traveling many thousands of kilometers. The paper takes the reader through the first iteration of the multi-iteration design process in order to show how much divert and acceleration are required by the kinetic kill vehicle to hit the target. Simplified examples are presented to indicate how conventional guidance and filtering techniques can be used as a starting point in the iterative design process for this important problem in missile defense. More advanced guidance and filtering techniques can be used in subsequent iterations to more accurately size the kinetic kill vehicle and improve system performance and robustness.

Survivability of China's Sea-Based Nuclear Forces

Abstract: The survivability of China's ballistic missile submarines and submarine-launched ballistic missiles is examined. First, the Type 094 ballistic missile submarine is noisy and vulnerable even in shallow waters. This suggests the urgency for China to improve the quietness of the Type 094. Second, after the deployment of the U.S. interceptor missile, SM-3 Block IIA, in 2018, China's intercontinental ballistic missiles and submarine-launched ballistic missiles launched from Chinese coastal waters would face a three-layer engagement, constructed by SM-3 IIAs deployed near China's coastal waters, ground-based interceptors deployed in California and Alaska, and SM-3 IIAs deployed near U.S. coastal waters respectively. These deployments could undermine the credibility of China's nuclear deterrence. It would be well for China and the United States to work together to improve strategic stability between these two states.

The Law of Operational Targeting: Viewing the LOAC Through an Operational Lens

Abstract: Understanding how air and missile warfare is planned, executed, and regulated requires more than just an understanding of relevant LOAC provisions. In U.S. practice (and that of many other countries), air and missile warfare is one piece of a broader operational mosaic of law and military doctrine related to the joint targeting process. Air and missile warfare is embedded within this broader targeting process. Accordingly, a genuine understanding of the law of air and missile warfare necessitates understanding how the LOAC influences and is integrated within this targeting process. How operational commanders select, attack, and assess potential targets and how the LOAC reflects the logic of military doctrine related to this process is therefore the objective of this Essay. To achieve this ‘objective’, the authors will focus on a recent decision by the International Criminal Tribunal for the Former Yugoslavia, Prosecutor v. Gotovina. Although the military operation at the center to this case involved only limited use of air and missile warfare, the Tribunal’s extensive focus on the use of artillery and rocket attacks provides a useful and highly relevant illustration of why understanding the interrelationship between law and military doctrine is essential for the logical and credible development of the law. The author’s therefore seek to ‘exploit’ this case as an opportunity to expose the reader to this interrelationship, an interrelationship equally essential to the effective evolution of the law of air and missile warfare.

North Korean Ballistic Missile Threat to the United States

Abstract: : This report reviews North Korea's ballistic missile program. On July 4-5, 2006, North Korea test-launched seven ballistic missiles, including a new Taepo Dong 2 that failed soon after launch. Apparently successful shorter-range missile tests at the time included some combination of SCUDs and No Dongs. In October 2006, North Korea conducted an underground low-yield nuclear test and said it would deploy nuclear weapons on its ballistic missiles, although there is no evidence they are doing so. The Administration will ask the 110th Congress to fund a National Missile Defense (NMD) site in Europe, which some analysts argue is needed because of the threat of North Korean ballistic missiles to Europe. This report will be updated as events warrant. Additional information is provided by CRS Report RL33590, North Korea's Nuclear Weapons Program, by Larry A. Niksch.

Robust Height Control System Design for Sea-Skimming Missiles

Abstract: Sea-skimmingmissiles are required to fly at a very low height over themean sea level in order to avoid detection on the one hand and to inflict substantial damage to the enemy ship on the other. The height control system of a seaskimming missile experiences a disturbance because of sea waves, which increases the probability of the missile ditching into the sea. The unmodeled dynamics and varying aerodynamic coefficients further compound the task of the height control system. In this paper, a novel method for height control based on the extended state observer, which enables an estimation of the sea-wave disturbances in real time, is proposed. The estimate can be used for realtime planning of the skimming altitude. Simulation results show that the height control system functions effectively in the presence of significant sea-wave disturbances. Finally, the proposed design is compared with some existing designs reported in the literature.