Showing papers on "Missile published in 2000"

Design of Missile Guidance Law via Variable Structure Control

Abstract: New missile guidance law is proposed via variable structure control. The acceleration command is determined considering the target acceleration information as uncertainty. Target and missile are assumed to be point masses moving in the two dimensional plane. According to the property of the missile acceleration command, the proposed guidance laws are classified into IPN type and RTPN type. Moreover, it is shown that the conventional proportional guidance laws can be derived from the proposed guidance law. Numerical simulation results show that the proposed guidance law exhibits better performance compared to the conventional proportional guidance laws.

Sliding Mode Control with Optimal Sliding Surfaces for Missile Autopilot Design

Abstract: A new method is introduced to design sliding mode control with optimally selected sliding surfaces for a class of nonlinear systems The nonlinear systems are recursively approximated as linear time-varying systems, and corresponding time-varyingsliding surfaces are designedfor each approximatedsystem so thatagivenoptimization criterion isminimizedThe control input,which is designedbyusing an approximatedsystem, is then applied to the nonlinear system The method is used to design an autopilot for a missile where the design requirement is to follow a given acceleration command The sliding surface is selected such that a performance index formed as a function of angle of attack, pitch rate, and velocity error is minimized It is shown that the response of the approximating sequence of linear time-varying systems converges to the response of the missile

Robotic interception of moving objects using an augmented ideal proportional navigation guidance technique

Abstract: Presents an approach to online, robot-motion planning for moving-object interception. The proposed approach utilizes a navigation-guidance-based technique, that is robust and computationally efficient for the interception of fast-maneuvering objects. Navigation-based techniques were originally developed for the control of missiles tracking free-flying targets. Unlike a missile, however, the end-effector of a robotic arm is connected to the ground, via a number of links and joints, subject to kinematic and dynamic constraints. Also, unlike a missile, the velocity of the robot and the moving object must be matched for a smooth grasp, thus, a hybrid interception scheme, which combines a navigation-based interception technique with a conventional trajectory tracking method is proposed herein for intercepting fast-maneuvering objects. The implementation of the proposed technique is illustrated via numerous simulation examples.

Quasi-LPV modeling and LPV control of a generic missile

Abstract: In this paper, we will apply linear parameter-varying (LPV) control theory to the design of gain-scheduled missile autopilot. A nonlinear coupled 3-axis generic missile model is used as our design example. We will show that this model can be reduced to quasi-LPV form so that LPV design methodology can be applied. Simulation of the gain-scheduled controller with the nonlinear missile model yields excellent results and serves to validate both the quasi-LPV modeling procedure and the LPV control theory in practice.

Application of an Adaptive Autopilot Design to a Family of Guided Munitions

Abstract: A previously developed autopilot featuring a dynamic inversion control law augmented by an on-line neural network is applied to control a variant of the Joint Direct Attack Munition (JDAM). The inverting control law is based on a simple linear model of the plant at a single flight condition. The neural network adaptively regulates error in the plant inversion that occurs throughout the flight envelope due to the use of an approximate model. The autopilot design is performed using minimal information from an approximate aerodynamic data set generated using Missile DATCOM. The design is then validated in a nonlinear simulation using the complete DATCOM database. A comparison of performance is made with the traditionally designed JDAM autopilot, which makes extensive use of gain scheduling. To demonstrate the ability to tolerate a lack of wind tunnel data during control system synthesis, the same autopilot design is then evaluated in a nonlinear simulation that employs flight-validated, wind-tunnel-ba sed aerodynamic data. The autopilot is shown to successfully adapt by accounting for modeling errors and system nonlinearities throughout the flight envelope, eliminating the need for gain scheduling, and demonstrating the potential for dramatic reduction in dependence on wind tunnel data, which translates directly to a saving in development cost.

A simple model for calculating ballistic missile defense effectiveness

Abstract: This paper develops a probabilistic model that can be used to determine the technical performance required for a defense to meet specific political/military objectives. The defense objective is stated as a certain probability that no warheads leak through the defense. The technical performance is captured by the interceptor single‐shot probability of kill and the warhead detection, tracking, and classification probability. Attacks are characterized by the number of warheads and undiscriminated decoys. Barrage and shoot‐look‐shoot firing modes are examined, with the optimal interceptor allocation derived for the shoot‐look‐shoot mode. Applications of this model for sizing national and theater missile ballistic missile defenses are discussed.

Numerical Simulation of Transient Jet-Interaction Phenomenology in a Supersonic Freestream

Abstract: The objective is to evaluate the transient effects of a reaction control jet on the aerodynamic performance of a genericinterceptormissileoperating at supersonice ightconditions.Three-dimensionalcomputationsofthehighly turbulent e owe eld produced by a pulsed, supersonic, lateral-jet control thruster interacting with the supersonic freestream and missile boundary layer of a generic interceptor missile are evaluated at different altitudes and thruster conditions. A generic missile interceptor cone guration consisting of a long, slender body containing e xed dorsal and tail e ns is simulated. Parametric computational e uid dynamic solutions are obtained at altitude conditions corresponding to 19.7 and 35.1 km for 1 ) steady-state conditions with the lateral control jet turned off, 2) steady-state conditions with the lateral control jet turned on, 3 ) transient jet startup conditions, and 4 ) transient jet shutdown conditions. A thermally and calorically perfect gas with a specie c heat ratio equal to 1.4 was assumed for both the Mach number 5 freestream and Mach number 3 lateral jet. Vehicle forces and moments are assessed from each solution by integrating the surface pressures and viscous shear stresses computed on the missile surfaces. These results are used to determine the ine uence of the jet-interaction effects on the transient aerodynamicperformanceofthemissile.Theanalysispredictsstrongtransientine uencesfortheintegratednormal force and pitching moment.

Robustness of a nonlinear missile autopilot designed using dynamic inversion

Abstract: An inner-loop/ou ter-lqop dynamic inversion control architecture with output redefinition in the inner-loop is employed to synthesize a full-envelope nonlinear autopilot for an air-to-air missile. The autopilot tracks pitch and yaw acceleration commands while regulating body roll rate to zero. Essential design parameters are scheduled with flight condition for optimal performance. The autopilot has been subjected to a variety of robustness tests. Linear robustness analysis was based on linearized models computed locally throughout the flight envelope and included determination of classical gain and phase margins as well as vector margins associated with simultaneous gain and phase variations. Nonlinear robustness analysis was based on single-run and Monte Carlo simulations and included determination of maximum allowable gain variations and input delays as well as sensitivity to variations in aerodynamic parameters.

Missile Aerodynamic Shape Optimization Using Genetic Algorithms

Abstract: The use of pareto genetic algorithms (GAs)to determine high-efe ciency missile geometries is examined, and the capabilityofthesealgorithmstodeterminehighlyefe cientandrobustmissileaerodynamicdesignsisdemonstrated, given a variety of design goals and constraints. The design study presented documents both thelearning capability of GAs and the power of such algorithms for multiobjective optimization. Results indicate that the GA is clearly capable of designing aerodynamic shapes that perform well in either single or multiple goal applications.

Nonlinear Control for Missile Terminal Guidance

Abstract: Variable Structure Control (VSC) technique is applied to the design of robust homing missile guidance laws. In the design procedure, the target’s maneuver is assumed to be unpredictable and is considered as disturbances. Guidance laws are then proposed to achieve the interception performance for both cases of longitude-axis control being available and unavailable. The proposed guidance laws are continuous which alleviate chattering drawback by classic VSC design. Results are obtained and compared with those by realistic true proportional navigation design to illustrate the benefits of the proposed design. @S0022-0434~00!00604-3#

Adaptive control for feedback-linearized missiles with uncertainties

Abstract: A robust adaptive control scheme is proposed that can be applied to a practical autopilot design for feedback-linearized skid-to-turn (STT) missiles with aerodynamic uncertainties. The approach is to add a robust adaptive controller to a feedback-linearizing controller in order to reduce the influence of the aerodynamic uncertainties. The proposed robust adaptive control scheme is based on a sliding mode control technique with an adaptive law for estimating the unknown upper bounds of uncertain parameters. A feature of the proposed scheme is that missile systems with aerodynamic uncertainties can be controlled effectively over a wide operating range of flight conditions. It is shown, using Lyapunov stability theory, that the proposed scheme can give sufficient tracking capability and stability for a feedback-linearized STT missile with aerodynamic uncertainties. The six-degree-of-freedom nonlinear simulation results also show that good performance for several uncertainty models and engagement scenarios can be achieved by the proposed scheme in practical night conditions.

Radar Signal Processing

Abstract: ■ This article recounts the development of radar signal processing at Lincoln Laboratory. The Laboratory’s significant efforts in this field were initially driven by the need to provide detected and processed signals for air and ballistic missile defense systems. The first processing work was on the Semi-Automatic Ground Environment (SAGE) air-defense system, which led to algorithms and techniques for detection of aircraft in the presence of clutter. This work was quickly followed by processing efforts in ballistic missile defense, first in surface-acoustic-wave technology, in concurrence with the initiation of radar measurements at the Kwajalein Missile Range, and then by exploitation of the newly evolving technology of digital signal processing, which led to important contributions for ballistic missile defense and Federal Aviation Administration applications. More recently, the Laboratory has pursued the computationally challenging application of adaptive processing for the suppression of jamming and clutter signals. This article discusses several important programs in these areas.

Tracking and intercepting spiraling ballistic missiles

Abstract: Intentional or unintentional spiraling manoeuvres on the part of a tactical ballistic missile target can make it particularly difficult for a pursuing missile to hit. The paper first presents normalized miss distance curves showing how the target spiraling frequency and amplitude along with the interceptor guidance system time constant determine the miss distance for a proportional navigation guidance system. It is then shown how more advanced guidance techniques can be used to improve the system performance against spiraling targets. The advanced guidance techniques require knowledge of various target states plus the target weave frequency. Various Kalman filtering options for estimating the states required for the advanced guidance law are presented. Preliminary miss distance results are presented with each of the candidate filtering options.

Surface-Based Air Defense System Analysis

Abstract: Threat characterization air defence process models and events tactical environments anti-aircraft artillery surface to air missile guidance concepts missile element models and trim flight simulation guidance and control warheads and fuses simulation and engagement applications air defence mission modeling, air defence system test and evaluation.

Initiating device for use with telemetry systems

Abstract: A substitute solid state device for safely initiating a sustainer motor is provided. The substitute device replaces a mechanism that is integral to a warhead. The substitute device interfaces to a telemetry package and is suitable for insertion into small housings. A specific embodiment is a substitute interface to a telemetry system incorporating a circuit for firing a sustainer motor of a small missile or rocket. The substitute interface replaces the interface and firing circuit associated with the warhead in a missile of 2.75-inch diameter, such as the STINGER missile.

Aircraft missile-hit survivability using infrared lamp and sacrificial support structure

Abstract: An aircraft missile vulnerability reduction system based on missile hit acceptance whereby a targeted aircraft's most critical components are protected by a preprogrammed, missile-attracting infrared decoy strategically positioned on a sacrificial portion of the aircraft's structure. The decoy is optimally located based on vulnerability analyses and includes multiple modes of operation that configure to instantaneous survivability needs. The system is capable of providing aircraft survivability against shoulder launched man-portable air defense systems missiles during low-level mission flight scenarios.

Method and apparatus providing an interface between an aircraft and a precision-guided missile

Abstract: An interface between an aircraft and a precision-guided missile having automatic target recognition capability receives target image data and target location data from the aircraft, translates the data into formats usable by the missile, and downloads the target data to the missile at any time prior to launch of the missile. The interface includes a mission-planning unit and a terrain and elevation data storage unit enabling the air crew to call up terrain and elevation data on a visual display for planning a missile mission, and to transmit mission parameters to the missile during aircraft flight.

Receding Horizon Guidance Laws with No Information on the Time-to-Go

Abstract: In this paper a modie ed optimal guidance law is proposed that does not use information on the time-to-go. The proposed receding horizon guidance law (RHG) is based on the receding horizon strategy and optimal control theory. In the presence of arbitrary target maneuvers and an initial lateral miss distance (MD) rate between the target and the missile, the proposed RHG is shown to guarantee to keep the lateral MD less than the given value, within which the warhead of the missile is detonated, from the appropriately selected time to the intercept time. Through threesimulation examples theability oftheRHGto interceptthetarget isillustrated. The performanceof theRHGiscompared with theoptimalguidancelawin termsoftheterminal MDwhen thetime-to-goisinaccurate, and in terms of the lateral MD and the missile acceleration when the time-to-go is accurate.

Non-orthodox guidance law development approach for the interception of maneuvering anti-surface missiles

Abstract: The paper concentrates on two aspects of a new mind setting applied to interceptor guidance: (i) the mathematical formulation of intercepting highly maneuverable targets and (ii) the relationship between the estimation process and optimal guidance law design. The interception of a maneuverable anti-surface missile is formulated as a zero-sum pursuit evasion game. The perfect information game solution, which guarantees a robust "hit-to-kill" homing accuracy, requires (inter alia) the knowledge of the target maneuver. This variable cannot be directly measured and has to be estimated, based on noise corrupted measurements. The greatest error source in the estimation of time-varying target maneuvers is the inherent delay due to the convergence time of the process, hi this paper the estimation process of the target maneuver is modeled by a pure information delay. Based on this model a new guidance law, compensating for the delay, is developed. This non-orthodox approach represents a potential breakthrough in guidance law design predicting reduced miss distances and robustness even in stressing interception environments. The improved accuracy was confirmed by a set of Monte Carlo simulations in a noise corrupted interception scenario.

Ballistic-Missile Defence And Strategic Stability

Abstract: Ballistic-missile proliferation national missile defence theatre-missile defence boost-phase ballistic-missile defence.

Predictive Missile Guidance

Abstract: Guidance to intercept a maneuvering target is considered. Uncertainty in the predicted target position at interception is handled by constructing a Gaussian-sum approximation to the probability density function of that position.Aguidanceframework inspiredbymodelpredictivecontrolispresented,withtheobjectiveofmaximizing theprobability ofsuccessful interception, and simplie cationsto make thecomputations feasibleare suggested. The schemeis extended to the multitargetcase, incorporating uncertain information on target identity.Themultitarget procedure allows compromise between progress toward the selected target and keeping as many targets reachable as possible. Simulation results illustrating performance improvements over conventional guidance are presented. Nomenclature a = lateral acceleration C = maximum number of maneuver changes allowed = missile effectiveness function J = cost function k = discrete-time instant L = prediction horizon M = control horizon, number of update intervals to interception Mi = maneuver history N = number of possible target maneuver actions (x, P) = Gaussian probability density function with mean x, covariance P

Method and guidance system for guiding a missile

Abstract: The present invention relates to a method and an arrangement for guiding a missile. In accordance with the prior art, the angle position of a target (9) when the missile (3) is expected to reach the target is predicted on the basis of the angular velocity determined in a preceding time period. In order to improve the strike accuracy, the operator, in a second subsequent time period, tracks the actual position of the missile in relation to the predicted angle position of the target. If a deviation is observed, a correction command is transmitted to the missile in order to correct the missile trajectory. For this purpose, a communications link is provided to transmit the correction command given by the operator.

Nonlinear Problems in Aviation and Aerospace

Abstract: Aircraft as Adaptive Nonlinear System which Must be in the Adaptational Maximum Zone for Safety. Orbit Determination of a Tethered Satellite System Using Laser and Radar Tracking. Application of Automatic Theorem Proving (ATP) Approach to the Telescope Guidance. Attitude Stability of an Asymmetric Dual-Spin Spacecraft with Stochastic Rotor Speed Fluctuations. Full Envelope Missile Longitudinal Autopilot Design Using the State-Dependent Riccati Equation Method. Intelligent Control of Agile Aircraft. Feedback Noise Control in an Acoustic Chamber: Mathematical Theory. Estimation of Asymptotic Stability Regions of Nonlinear Systems by Use of Eigen-Vectors. Flight Control with and without Control Surfaces: A Nonlinear Look. Optimal Ascent Trajectories for a Single-Stage Suborbital Spacecraft. Nonlinear Dynamics of Two-Body Tethered Satellite Systems. Two- and Three-Dimensional Numerical Methods for Free Surface Hydrodynamics. Control of Structures with Sefl-Straining Actuators: Coupled Euler/Timoshenko Model: I. Building a Parallel Version of a "Real Gas" Flow Solver. A Probabilistic Method to Estimate a Missile Target. Reentry Control for Low L/D Vehicles. Exact Euler Aerodynamics via a Novel Method. Singular Perturbations and Time Scales in Aerospace Systems: An Overview. Planning for R&D Manpower in Aviation and Aerospace. Effects of Nonlinearities in Aerodynamic Coefficients on Aircraft Longitudinal Motion. Vector Lyapunov Function Synthesis of Aircraft Control. Control Systems with Parametrical and Structural Reconfiguration. Unified Control Systems. Ergodic Control of Stochastic Navier-Stokes Equation. Nonlinear Methods and Software for Dynamic Investigations of Fail-Safe Gyromoment Attitude Control Systems of Spacecrafts.

Low cost guidance for the Multiple Launch Rocket System (MLRS) artillery rocket

Abstract: The US Army Aviation and Missile Command has demonstrated the application of advanced technology to significantly improve the accuracy and range of the US Army's Multiple Launch Rocket System (MLRS) through the Guided MLRS Advanced Technology Demonstration (ATD). The addition of a cost-effective guidance and control package to the rocket results in a weapon system that can defeat the target at ranges up to 70 km with significantly fewer rounds. This not only increases the destructive capability of the system but also reduces the cost of the expended ammunition, the cost to transport the ammunition to the combat zone, and the number of launchers required to execute the mission. The guidance kit is housed in the nose of the MLRS and consists of an inertial measurement unit (IMU), four independent electro-mechanically actuated canards, a Global Position System (GPS) receiver, GPS antennas, a thermal battery, a guidance computer, and power supply electronics. Roll decoupling of the warhead and motor section was required to allow roll control of the guidance section to enable accurate inertial navigation and was accomplished by joining the two sections with a roll bearing. Five flight missiles were built and tested during the ATD. Two IMU vendors were selected to provide flight units (3 flights used vendor A and 2 flights used vendor B). A tightly coupled 8 channel GPS receiver was flown on all flights. This paper discusses the ATD development effort and presents flight test results.

Articulated nose missile control actuation system

Abstract: A missile nose is tiltable and rotatable relative to a missile body through the action of an actuator system. In an exemplary embodiment, the actuator systems uses two electro-mechanical actuators mounted co-axially and having the output shaft of one actuator fed through the shaft of the other. One of the actuators controls a tilt angle between a longitudinal axis of the body and a longitudinal axis of the nose. The other actuator rotates the nose about the longitudinal axis of the body. A method of steering a missile includes using the actuator system to maintain the missile nose pointed at a target or other desired destination.