Tactical Missiles Research Articles

Overview of activities at the ISL hypersonic shock tunnels

The main activities of the ‘Aerothermodynamics and Shock Tube Laboratory’ deal with studies of the aerothermodynamics of high-speed projectiles and missiles and their related steering systems, of sub-munitions ejected from tactical ballistic missiles and of interceptors of re-entry vehicles. The main advantage of using shock tunnels for aerothermodynamic investigations is the reproduction of real flight conditions of vehicles at a very low cost. Many studies are conducted with industrial partners to gain a realistic insight into the physics of the flow around models of real vehicles and to build a useful database for the validation of their numerical simulations. The present paper is dedicated to the measurement methods in use at the hypersonic shock tunnels and to the recent research subjects investigated in these facilities.

Overload Control System Design of a Deflectable Nose Missile

Deflectable nose missile is a novel supersonic morphing missile with different characteristics from the ordinary tactical missiles. In this paper, the dynamic model is divided into the equivalent pitching equations and the equivalent yawing equations as the roll-channel control system of missile works ideally. Then open-loop stability of both the equivalent pitching equations and the equivalent yawing equations are analyzed respectively. After that, the variable structure control theory is employed to design both the overload direction control loop and overload magnitude control loop for a deflectable nose missile. Simulation result shows that closed-loop overload control system can track both the direction and magnitude of overload signal quickly and accurately.

Modeling Flight Dynamics of Tactical Missile with Morphing Wing

Morphing wings for winged tactical missile are gaining increasing concern for their potential to improve flight performance. However, morphing wings bring some new challenges to modeling flight dynamics due to movable components. This paper develops a set of complete nonlinear model, where some additional inertial terms are included. These terms account for the impact of morphing wing on flight states and make it difficult to study dynamic characteristics of missile. Therefore, a simplified model is deduced based on some reasonable assumptions. As a result, a longitudinal dynamic model is decoupled from the complete model. To verify the model, a numerical simulation is completed. The results show that the speed of wing changing has a notable effect on motion parameters during transition from one configuration to another, that is, the rapid wing changing means the larger amplitude and the higher frequency of motion vibration.

Bounds on the RMS Miss of Radar-Guided Missiles

In preliminary analysis of guided systems, it is required to assess the miss distance performance from some small set of parameters. This paper presents analytical formulas of bounds on the achievable rms miss by a radar-guided missile against a variety of target maneuvers. These formulas use a set of core parameters that affect the miss distance; thus, they can be used for synthesis and analysis of the performance of radar-guided tactical missiles. The bound is derived, subject to the assumption that the missile guidance law and estimator are fully matched to the missile dynamics, the target maneuver, and the glint noise. The glint is the dominant noise source, the missile applies frequency agility, and there is no missile acceleration limit. No system can achieve smaller rms miss distance than the one presented, subject to the stated assumptions.

Applications of adjoint theory to problems in aerospace and defence science

The adjoint simulation method is an efficient, computerised method for the performance analysis of linear time varying systems excited by deterministic and/or stochastic inputs. It is based on the impulse response function (or weighting function) of the so-called adjoint system---an associated linear system derived from the original system by clever utilisation of the mathematical principle of duality. We demonstrate the power of adjoint simulation in the context of guided missile homing loop studies and present a Matlab tool for its speedy implementation and execution. As an example, the tool analyses the miss distance performance of a generic guided missile against an evading target in two dimensional space. References Statistical performance analysis of nonlinear stochastic systems by the Monte Carlo method volume 23-1 of Mathematics and Computers in Simulation J. , pages 21--23, 1981. doi:10.1016/0378-4754(81)90004-5 Zarchan, P. Tactical and Strategic Missile Guidance , 5th Edition, AIAA Progress in Astronautics and Aeronautics, 2007. Weiss, M. Adjoint Method for Missile Performance Analysis on State-Space Models, volume 28-2 of Guidance, Control and Dynamics J. , pages 236--248, AIAA ,2005. Laning, J. H. and Battin, R. H. Random Processes in Automatic Control , McGraw-Hill Book Company, New York, NY, 1956. D. Bucco and M. Weiss. Development of a Matlab/Simulink Tool to Facilitate System Analysis and Simulation via the Adjoint and Covariance Methods, AIAA MST Conference , Aug 2007. http://www.aiaa.org/agenda.cfm?lumeetingid=1501&formatview=1&dateget=22-Aug-07 DeRusso, P. M., Roy, R. J., Close, C. M., and Desrochers, A. A. State Variables for Engineers, 2nd Edition , John Wiley and Sons, Inc., New York, NY, 1998. Moretti, G. Best Practices for Adopting Model-Based Design in Electronic System Development, White-paper, Gabe on EDA , 2007. http//www.mathworks.com/products/simulink/technicalliterature.html

스트랩다운 탐색기 및 MEMS 센서를 이용한 유도필터 설계

본 논문에서는 저가의 스트랩다운 센서 및 탐색기 기반의 정밀한 유도필터 설계를 다룬다. 고려된 스트랩다운 센서는 3축의 가속도계와 자이로로 구성된 IMU, 3 축 자기장계 및 압력고도계이다. 유도탄의 위치, 속도, 자세 및 압력고도계의 바이어스 오차가 유도필터의 상태변수로 고려된다. 상태방정식 및 측정방정식의 비선형성이 크기 때문에 UKF(Unscented Kalman Filter)를 도입한다. 제안된 유도필터는 표적 위치오차가 없을 경우 항법필터로 동작한다. 표적오차가 존재하는 경우에도 유도탄-표적간 상대 정보를 정확히 추정함으로서 정밀한 유도성능을 보장한다. 특수한 교전상황에서는 유도필터의 가관측성 문제가 발생함이 확인되었다. Precision guidance filter design for a tactical missile with a strapdown seeker aided by low-cost strapdown sensors has been addressed in this paper. The low-cost strapdown sensors consist of an IMU with 3-axis accelerometers and gyroscopes, 3-axis magnetometers, and a barometer. Missile's position, velocity, attitude, and bias error of the barometer are considered as state variables. Since the state and measurement equations are highly nonlinear, we adopt UKF(Unscented Kalman Filter). The proposed guidance filter has a function of a navigation filter if target position error is not considered. In the case that the target position error is introduced, the proposed filter can effectively estimate the relative states of the missile to the true target. For specific engagement scenarios, we can observe that observability problems occur.

Poland: Straddling the Nuclear Frontier

TEMPLEWO, POLAND—Hidden in the outskirts of the Lagowski forest, three kilometers from this small village in far northwestern Poland, stand the remnants of a former Soviet military base. Dilapidated buildings, dark and hollow, are stripped of windows and doors, the plumbing and electrical cords ripped from their housings. Chunks of concrete lie scattered in the long grass. It is hard to imagine that only two decades ago, more than 50,000 Russian soldiers were stationed on Polish soil in facilities like this one, known as Base 3003. Look more closely, and one sees reinforced bunkers and walls painted with fading symbols denoting dangerous radioactivity, a chilling reminder of the Cold War and the deadly purpose of this vacant base. From this unit, nucleartipped tactical missiles were on permanent alert, targeted at Western Europe. The Soviets may be long gone, but the sense of insecurity that defined the period of occupation remains woven throughout Polish society. That the fledgling democracy, born in Gdansk in 1979, which led to the fall of communism ten years later, enabled the disclosure of many past secrets—including the existence and mission of this base— only has deepened this feeling of profound unease. Today, Poland still looks eastward, anxious to see how Russia plans to regain its central position on the world stage, and concerned that Moscow will act on its barely disguised intentions of regaining as much as possible of what used to be its sphere of influence. Although Poland has become an eager member of the North Atlantic Treaty Organization (NATO) and European Union, it hasn’t overcome the fear that there is still a very real risk of its becoming yet again a victim of East-West realpolitik. For many politicians and analysts, a projected Russian-German gas pipeline, bypassing Poland and undermining its energy security, coupled with the debate over placing an American anti-missile defense system or indeed any significant NATO infrastructure on Polish territory are all unsettling signs that Poland is still being treated as a bargaining chip in the game of the major powers. Poland’s modern trauma began in 1939, when foreign ministers of Germany and Russia signed the Ribbentrop-Molotov pact, effectively dividing Poland between the Nazis and the Soviets. Hitler invaded Poland from the west on September 1, 1939, just eight days after the ink had dried. The Russians entered its eastern regions 17 days later, under the pretext of defending Soviet citizens living in Poland. Some five years after, at the end of World

Three-Dimensional Validation of an Integrated Estimation/Guidance Algorithm Against Randomly Maneuvering Targets

S UCCESSFUL interception of maneuvering tactical ballistic missiles (TBM), requiring very small miss distances or even a direct hit, has been a challenging problem since their reintroduction as a terror weapon in the 1991GulfWar. At the Faculty of Aerospace Engineering of the Technion—Israel Institute of Technology, a multiyear research has been conducted investigating the difficulties of effective ballistic missile defense (BMD). It has been aimed to identify and correct the deficiencies of the conservative common practice in the estimation/guidance law design. In the last years, several papers dealing with this yet unsolved problem were published [1–9]. In a recently published work [9], an integrated estimation/guidance design paradigm against randomly maneuvering targets was introduced, based on several innovative concepts that provide robust satisfactory homing performance. The main ideas involved in this revolutionary design concept were developed and tested by using a simplified linearized planar (horizontal) constantspeed model of the interception scenario. A set of Monte Carlo simulations demonstrated that in such scenarios this new approach yields a substantial improvement in homing accuracy, compared with earlier results. The simplified mathematical model of the interception scenario raised two critical questions. The main concern has been whether an algorithm that was developed for a time-invariant planar model will perform well in a realistic endoatmospheric BMD scenario, which is inherently three-dimensional with variable speeds and maneuverability constraints. The other question related to target maneuver types. Because the study in [9] was focused on a single maneuver structure (a bang–bang type with random switching time), can the algorithm deal with other types of feasible target maneuvers? The objective of the present Note is to provide answers to these questions by reporting the results of an extensive simulation study evaluating the validity of the integrated estimation/guidance algorithm of [9] in a set of three-dimensional nonlinear endoatmospheric BMD interception scenarios. The test was performed against two types of the most stressing random target maneuvers: namely, the bang–bang-type with random switching time (used in [9]) and a periodical random-phase maneuver discussed in some recent work [10]. Although an eventual threat can generate other maneuver structures, they will be less effective and therefore less likely. Early distinction between the two types of evasive maneuvering is one of the new elements of this study,modifying the originally planar algorithm of [9] to suit a realistic three-dimensional environment. The limited length of a Technical Note did not allow elaborating on the theory and the underlying mathematics. More details can be found in the references and, in particular, in [9]. The structure of this Note is the following. In the next section, the three-dimensional BMD problem is formulated. In Sec. III, the main elements of the integrated estimation/guidance algorithm used in [9] are summarized and the modifications needed for its application in a realistic three-dimensional BMD are outlined. This is followed by the scenario data, including the generic target and interceptor models used in this validation study. The three-dimensional simulation philosophy and the results of extensive Monte Carlo simulations are presented in Sec.V. Summary and conclusions are offered in Sec.VI.

Interacting multiple model filter for tactical ballistic missile tracking

An interacting multiple model (IMM) filter is presented for the real-time tracking of tactical ballistic missiles (TBMs). The novel aspects of the proposed IMM filter include the development of a constant axial force (CAF) Kalman filter, asymmetric IMM state interaction, and an entropy-based variation of the IMM mode probability update equation. Using data from a recent TBM defense (TBMD) test event, the proposed IMM filter is shown to yield consistent state estimates throughout the entire TBM trajectory, which includes a dual-stage boost during launch.

Modeling and optimization of integration processes using dynamic programming

AbstractIncremental integration of systems is investigated. The modeling problem to predict the properties (cost and duration) of a given integration process, and the optimization problem to find the optimal integration order are addressed. The proposed integration model is divided into two parts: a time duration effort model and a cost effort model. Both models accumulate the major cost elements and time durations involved with the integration process. Dynamic Programming is employed to find the time and effort optimal integration orders. The methodology is demonstrated by a small tactical missile integration process. © 2008 Wiley Periodicals, Inc. Syst Eng

Asymptotically Optimal Nonlinear Filtering: Theory and Examples with Application to Target State Estimation

The State-Dependent Riccati Equation (SDRE) filter, which is derived by constructing the dual of the well-known SDRE nonlinear regulator control design technique, has been studied in various papers, with mainly practical investigations of the filter. Until recently, theoretical aspects of the filter had not been fully investigated, leaving many unanswered questions, such as stability and convergence of the filter. The authors conducted an investigation of the conditions under which the state estimate given by this algorithm converges asymptotically to the first order minimum variance estimate given by the extended Kalman filter (EKF). Conditions for determining a region of stability for the SDRE filter were also investigated. The analysis was based on stable manifold theory and Hamilton-Jacobi-Bellman (HJB) equations. In this paper, the motivation for introducing HJB equations is justified with mathematical rigor, which is given by reference to the maximum likelihood approach to deriving the EKF. The application of the SDRE filter is then demonstrated on challenging examples to illustrate the theoretical aspects and design flexibility (additional degrees of freedom) of the algorithm when loss of observability is encountered. In particular, a realistic and detailed evaluation of the filter is carried out for the problem of target state estimation in an advanced tactical missile guidance application for analysis in the optimal guidance problem for air-air engagements using only passive sensor (angle-only) information. Simulation results are presented which show dramatic tracking improvement using the SDRE target tracker.

Design and implementation of a high-velocity projectile generator

An explosively formed projectile (EFP) is designed as a high-velocity projectile generator to be used in a field test in which an equivalent fragment impacts on an equivalent tactical ballistic missile warhead. The formed slug of the EFP is ≈45 g and has a velocity of around 2500 m/sec. EFP detonation and slug forging are numerically simulated using an LS-DYNA3D finite-element code to optimize the design parameters of the EFP. Tests with determining EFP velocity and mass are performed to confirm the preliminary design and evaluate the EFP performance. A flash X-ray facility is employed to measure the profile and the velocity of the EFP slug. The high-velocity projectile generator developed herein can be used in verifying the lethality of the antitactical ballistic missile warhead against tactical ballistic missile. It is also useful for research of the resistance of military fortifications and nuclear power plant containment structures to penetration.

Quasilinear Parameter-Varying Autopilot Design Using Polynomial Eigenstructure Assignment with Actuator Constraints

In this paper, eigenstructure assignment is used in a polynomial matrix framework. In particular, such eigenstructure assignment does not impose any particular eigenvalues and the assignment is done in one-single pass over the flight envelope of a nonlinear missile. The eigenspace of the system is manipulated in polynomial matrix form and the closed-loop transfer function is expressed as a coprime factorization. The designer is left to choose the controller structure producing a flexible design approach. The approach enables the design to consider both static and dynamic controllers alike. In this paper, the approach is applied to a quasilinear parameter-varying missile and it is simple, attractive and comparable to other approaches while leading to a closed-loop system independent of the operating point. The approach is thus similar to dynamic inversion with a self-scheduled controller, but without the need to consider zero dynamics. A tail-controlled missile in the cruciform fin configuration is modeled as a second-order quasilinear parameter-varying system. A lateral velocity controller is designed for the nonlinear model of a tactical missile. The actuator dynamics are included and successively, the actuator dimensioning and the actuator dynamics effects are traded off against performance using the matching conditions developed herein.

Comparison of line-by-line and molecular band IR modeling of high altitude missile plume

This paper deals with the quantitative comparison of modeling IR radiation emitted from the plume of a tactical ballistic missile (TBM) in the boost phase with two different model approaches. IR spectra of the missile plume are calculated both with the high spectral resolution line-by-line radiation model FASCODE 3 (fast atmospheric signature code) using the databases HITEMP or HITRAN and the low spectral resolution IR radiation model NIRATAM ( NATO Infra Red Air TArget Model) using molecular band model technique. The influence of the atmosphere on the IR spectra as viewed from a space born sensor is taken into account. The results show, that using an elaborate line-by-line radiation model can improve the accuracy in computation of IR signature compared to the simpler but faster molecular band model technique used in NIRATAM.

EXPERIMENTAL INVESTIGATION OF A PARAFFIN BASED HYBRID ROCKET

Hybrid rockets are known to be simpler, safer, environmentally friend, and, more importantly, cheaper than most of the technologies for propulsion devices used today. Hybrid rockets can be applied as the propulsion system in satellites launch vehicles, micro-satellites and tactical missiles. This paper deals with combustion of ultra-high molecular weight polyethylene (UHMWPE) and paraffin as the solid fuels burning with gaseous oxygen (GOX) as well as N O as the oxidizer in lab scale hybrid rocket motors. A test 2 stand was built to carry out the experiments. The main objectives were to investigate the ignition of the solid fuels, burning performance and regression rates for different operating conditions. With paraffin-based fuel the hybrid motor had the regression rate enhanced two to three folds compared to the UHMWPE, as reported in the literature. The overall performance of the motor, with paraffin as the fuel, is comparable to other technologies. Paraffin-based hybrid rockets can, then, be a safer and cheaper alternative to satellite launch vehicles for the Brazilian space program.

DOES DUAL SOURCING LOWER PROCUREMENT COSTS?*

U.S. defense policy encourages the use of dual sourcing to reduce government procurement costs, but recent theoretical work raises doubts about the benefits of this policy. I study the determinants of dual sourcing and its effects on government procurement costs using a panel dataset of tactical missiles. I find dual sourcing is not driven by failures to reduce costs; instead, it is used more often after incumbent suppliers demonstrate quality control problems, and in settings where tacit collusion is likely to be difficult. After correcting for selection bias, dual sourcing is found to reduce government procurement costs significantly.

Novel Adaptive Generalized Likelihood Ratio Detector with Application to Maneuvering Target Tracking

A novel adaptive jump-detection algorithm is introduced for scenarios involving abrupt changes in the inputs to linear systems, such as those that might occur in tracking maneuvering targets. Improving upon the standard generalized likelihood ratio (GLR) detector, presented over two decades ago, the new algorithm is characterized by increased robustness with respect to uncertainties in the system input, which frequently arise in the context of target tracking applications. The performance of the new algorithm is demonstrated in an endgame scenario involving an interceptor missile and a maneuerable tactical ballistic missile. An extensive Monte Carlo simulation study is used to demonstrate the superiority of the method over the conventional GLR method in terms of its much smaller observed false alarm probability, which actually agrees with the theoretical value. The new algorithm also facilitates a correct isolation of the abrupt change, is consistent in the usual statistical sense, and generally proves more reliable.

Thermosets take the heat and pressure in missile propulsion systems

A thermoset composite component has solved a problem encountered in recent trials of tactical missiles by the US military. Alan Johnson of Norplex-Micarta explains.

Adaptive Estimation of Line-of-sight Rate Measurement from a Radio Frequency Seeker

The line-of-sight (LOS) rate output from a radio frequency (RF) seeker is widely used during the homing phase guidance of a tactical missile: The LOS rate is noisy and needs to be filtered. The application of an adaptive Kalman filter for the L.OS rate state estimation has been studied. This filter requires minimal a priori knowledge about technical parameters of the seeker. It is also capable of estimating the variable noise statistics.

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 under classical 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.