Showing papers on "Missile published in 2015"

Back-stepping active disturbance rejection control design for integrated missile guidance and control system via reduced-order ESO.

Abstract: This paper proposes a novel composite integrated guidance and control (IGC) law for missile intercepting against unknown maneuvering target with multiple uncertainties and control constraint. First, by using back-stepping technique, the proposed IGC law design is separated into guidance loop and control loop. The unknown target maneuvers and variations of aerodynamics parameters in guidance and control loop are viewed as uncertainties, which are estimated and compensated by designed model-assisted reduced-order extended state observer (ESO). Second, based on the principle of active disturbance rejection control (ADRC), enhanced feedback linearization (FL) based control law is implemented for the IGC model using the estimates generated by reduced-order ESO. In addition, performance analysis and comparisons between ESO and reduced-order ESO are examined. Nonlinear tracking differentiator is employed to construct the derivative of virtual control command in the control loop. Third, the closed-loop stability for the considered system is established. Finally, the effectiveness of the proposed IGC law in enhanced interception performance such as smooth interception course, improved robustness against multiple uncertainties as well as reduced control consumption during initial phase are demonstrated through simulations.

Lyapunov-based impact time control guidance laws against stationary targets

Abstract: Nonlinear guidance laws that consider impact time constraints are proposed. Two-dimensional and three-dimensional impact time control guidance laws are derived using Lyapunov stability theory. Under the consideration of the nonlinear kinematics, it is shown that the missile states converge to the desired equilibrium point by the Lyapunov stability theory. The singularity issue of the proposed guidance laws is also analyzed. Numerical simulations are performed to verify the performance of the proposed guidance laws.

Cooperative Optimal Guidance Laws for Imposing a Relative Intercept Angle

Abstract: Optimal control-based cooperative guidance laws, which enforce at intercept a relative geometry in between a group of missiles and a single maneuvering target, are presented. An example scenario of interest is that of intercepting a high-value target (such as a ballistic missile) by a team of cooperating interceptors arriving from different directions. The problem is posed in the linear quadratic framework, and closed-form analytic solutions are obtained for any team size with any linear missile dynamics. The performance of the cooperative guidance laws is investigated using a nonlinear two-dimensional simulation of the missiles’ lateral dynamics and relative kinematics. It is shown that cooperatively imposing a relative intercept angle between the missiles provides substantially better results than when each missile independently enforces, using a one-on-one strategy, a preselected intercept angle that satisfies the relative intercept requirement. It is also shown that the missiles’ acceleration requirem...

Unified approach to cooperative guidance laws against stationary and maneuvering targets

Abstract: This paper presents the unified cooperative strategies for the salvo attack of multiple missiles on the basis of the traditional proportional navigation (PN) algorithm. The cooperative guidance laws are developed in a quite simple formulation consisting of a PN component for target capture and a coordination component for simultaneous arrival. The centralized coordination algorithms have better performance when the global information of time-to-go can be obtained by each missile, whereas the decentralized coordination algorithms come into effect when the group member is only able to collect information from its neighbors. The cooperative strategies can achieve a simultaneous attack against both stationary and maneuvering targets. Numerical simulations are used to demonstrate that the proposed approaches are feasible and flexible for the salvo attack of multiple missiles. The capturability analyses of the cooperative guidance laws are also performed by discussing the selection of gain parameters.

Missile Guidance Law Based on Robust Model Predictive Control Using Neural-Network Optimization

Abstract: In this brief, the utilization of robust model-based predictive control is investigated for the problem of missile interception. Treating the target acceleration as a bounded disturbance, novel guidance law using model predictive control is developed by incorporating missile inside constraints. The combined model predictive approach could be transformed as a constrained quadratic programming (QP) problem, which may be solved using a linear variational inequality-based primal–dual neural network over a finite receding horizon. Online solutions to multiple parametric QP problems are used so that constrained optimal control decisions can be made in real time. Simulation studies are conducted to illustrate the effectiveness and performance of the proposed guidance control law for missile interception.

Finite-time cooperative guidance laws for multiple missiles with acceleration saturation constraints

Abstract: The problem of cooperative guidance of multiple missiles attacking a stationary target, which can be achieved by consensus of the times-to-go is illustrated in this study. First, the finite-time cooperative guidance (FTCG) law is put forwarded to realise rapid and precise consensus of the times-to-go of all the missiles. Then, the FTCG law is modified to accommodate the condition in the presence of acceleration saturation constraint, and global ultimately finite-time consensus of times-to-go is also guaranteed. Finally, in order to adapt the realistic situation that each missile can only employ neighbour-to-neighbour communication, the distributed FTCG law is proposed. This guidance law adopts the sequential method, and can also cope with acceleration saturation constraint. The simulation results based on current control scheme and the comparison with the previous method demonstrate the effectiveness of the proposed laws.

Partial Integrated Guidance and Control with Impact Angle Constraints

Abstract: Novel sliding-mode control laws are proposed in this paper to stabilize a class of uncertain nonlinear systems. Considering that the sign function, which is often used in the sliding-mode control can cause chattering of control input, the saturation function is used to take its place in proposed controllers. What is more, not only the proposed controllers are continuous but also convergence to the origin asymptotically and in finite time can both be guaranteed in theory. For asymptotic convergence, it is only required that uncertainties and disturbances are bounded and the bounds may be unknown by virtue of adaptive laws. The obtained results are then applied to partial integrated guidance and control design for a missile, completing desired terminal impact angle and hit-to-kill interception. Finally, simulations are conducted on the nonlinear longitudinal missile model and results demonstrate the effectiveness of the proposed method.

Adaptive Dynamic Surface Control for Integrated Missile Guidance and Autopilot in the Presence of Input Saturation

Abstract: This paper considers integrated guidance and control system with input saturation for homing missiles based on the three channels independence design idea. An auxiliary system is first introduced into the integrated guidance and control model for the pitch channel. Then, a smooth function and a Nussbaum type function are employed in the dynamic surface control design to deal with the problem of input saturation constraint. The proposed control scheme guarantees the desired interception performance and the stability of the missile dynamics. The similar control scheme is further applied to the yaw channel and roll channel respectively. Nonlinear 6-DOF simulations are carried out to demonstrate the effect of the approach.

Hypersonic Boost-Glide Weapons

Abstract: The United States, Russia and China are developing hypersonic boost-glide vehicles. A simple model of their trajectory is developed by assuming that the vehicle does not oscillate during the transition to equilibrium gliding. This model is used to analyze U.S. Department of Defense data on test flights for the Hypersonic Technology Vehicle-2. This glider's lift-to-drag ratio—a key performance parameter—is estimated to be 2.6. The model is also used to calculate the tactical warning time that a boost-glide attack would afford an adversary. Other aspects of boost-glide weapons’ military effectiveness are explored. Approximate calculations suggest that, compared to existing non-nuclear weapons, boost-glide weapons could penetrate more deeply but would be less effective at destroying silos. The distance at which a boost-glide weapon armed with a particle dispersion warhead could destroy a mobile missile is also calculated; it is expected to be significantly larger than for an explosive warhead.

Cooperative control of multi-missile systems

Abstract: This study addresses the cooperative control problem of multi-missile systems. It proposed a two-stage control strategy, aiming at simultaneous attack from a group of missiles at a static target. The first stage adopts a special distributed consensus protocol in order for all missiles to asymptotically achieve a consensus of states. During the second stage, the local sightline control law allows the missiles to independently reach the target. The dynamic equation of the missile agent is normalised to a quasi-double-integrator model which is convenient for designing the consensus protocol. The proposed strategy is suitable for missiles of different speeds that have been self-organised without air operations centres. Two convincing simulation results are given to illustrate the efficiency of the proposed method.

Cooperative Aircraft Defense from an Attacking Missile using Proportional Navigation

Abstract: A three-agent pursuit-evasion scenario where an Attacker missile using Proportional Navigation guidance pursues a Target aircraft is considered in this paper. The Target is aided by a Defender missile which is launched by a wingman and aims at intercepting the Attacker before it reaches the aircraft. An optimal control problem is posed which captures the goal of the Target-Defender team, namely, to maximize the separation between Target and Attacker at the instant of capture of the Attacker by the Defender. The optimal control law provides the heading angles for the Target and the Defender team.

A New Guidance Law for the Defense Missile of Nonmaneuverable Aircraft

Abstract: In this brief, a new guidance law for the defense missile of nonmaneuverable aircraft is formulated based on dynamic game considerations. First, a simple differential game of protecting a static target in 2-D, involving simple motions for the attacker and defender, is introduced. The analysis is then extended to a moving noncooperative target in 2-D, in view of the fact that a nonmaneuverable aircraft would not be able to cooperate with the defender. A heuristic solution for the game is proposed and tested, and the results of the 2-D analysis are then extended to 3-D to formulate a new guidance law for the defense missile called the command to optimal interception point (COIP) guidance law. The validity of the new guidance law is checked using trajectory and envelope simulations, built with high-fidelity 6-DOF models using the computer-aided design of aerospace concepts in C++ framework. Performance comparisons are shown between the COIP guidance law and the recently proposed airborne command to line-of-sight (A-CLOS) guidance law. The results show that the performances of COIP and A-CLOS guidance laws are almost identical in a coplanar engagement scenario, but the COIP law has the additional advantage of working with only position information, without the knowledge of motion of the players. In addition, in a noncoplanar engagement case studied, the defense missile is shown to achieve intercept using the COIP guidance law, but fails when using the A-CLOS guidance law.

Sliding mode-based intercept guidance with uncertainty and disturbance compensation

Abstract: This paper presents a missile intercept guidance law that can account for uncertainty and disturbance. The proposed guidance law is developed based on a novel second order sliding surface, along with an uncertainty and disturbance estimator. The proposed sliding surface is invariant for the non-impact angle constraint case as well as the impact angle constraint case. The sliding surface guarantees finite time convergence of the line-of-sight (LOS) rate and (if specified) the LOS angle error, characterized by a simple function of time-to-go. Furthermore, the proposed strategy is also effective against a maneuvering target. The line-of-sight rate convergence property can be adjusted using only one parameter that makes the design process simple. Potential of the proposed guidance laws is demonstrated with some simulations.

All-Aspect Three-Dimensional Guidance Law Based on Feedback Linearization

Abstract: A nonlinear three-dimensional all-aspect guidance problem of an acceleration-constrained missile is dealt with. The feedback linearization method is applied to derive a three-dimensional guidance law, which enables the missile to intercept a maneuvering target under all-aspect initial boresight and heading conditions. The new guidance law is characterized by convergence to a collision course. It is shown that the proposed guidance law enables interception where the proportional navigation and the augmented proportional navigation guidance laws fail. Simulations demonstrate that the proposed law has the capability to perform several interception trials.

Partial integrated missile guidance and control with state observer

Abstract: This paper conducts a partial integrated guidance and control design for missile interception. With only the output available for feedback, a novel state observer is firstly proposed in the presence of unknown disturbances. The proposed observer reconstructs full system states in finite time. Interestingly, observer parameter is updated by an adaptive law. Then, a terminal sliding mode controller based on the proposed observer ensures the system states converge to zero in finite time, which is proved by the Lyapunov stability theory. The obtained result is applied to partial integrated guidance and control design of missile and hit-to-kill interception is achieved. Finally, a simulation example is presented, and a comparison to standard sliding mode observer is discussed to illustrate effectiveness of the proposed method.

FPGA (Field Programmable Gate Array) based ground launching control device of small and medium-sized rocket

Abstract: The invention provides an FPGA (Field Programmable Gate Array) based ground launching control device of a small and medium-sized rocket. The device comprises a main control computer, a ground control box, a signal conditioning case which uses FPGA as the core, and a missile device; the main control computer receives and feeds back a signal through an RS422 communication interface; the ground control box is used for performing hardware control for the system; the signal conditioning control case comprises the combination of a PCB and a power supply; the PCB comprises a level isolation conversion circuit which uses the FPGA as the core, a power-on sequence control circuit, a voltage AD acquiring circuit, an RS422 isolation conversion circuit, an RS422 relay circuit, a level conversion circuit in a head power supply circuit, and a corresponding filter circuit; the missile device comprises a missile distributor, a missile battery combination and a missile electrical device. With the adoption of the device, the functions of supplying power to the missile device from the ground, activating the missile battery, converting power, cutting off power supply, controlling a pressure release valve, and controlling ignition can be realized; the device has the characteristics of being safe, reliable, small in cost, short in development cycle, fast in speed, high in efficiency, and high in real-time performance.

Dynamic-Escape-Zone to Avoid Energy-Bleeding Coasting Missile

Abstract: This study deals with the problem of planar safe flight of a fighter aircraft in the presence of a pursuing “energy-bleeding” coasting missile. A“dynamic-escape zone” is proposed as a novel real-time aid for the aircrew to decide when to commence the latest yet safe-kinetic-evasion (that is, missile outrunning) from an already launched missile. Such safe evasion is based on exhausting the energy of the adversary missile to avoid missile rendezvous. At the instance of its calculation, the dynamic-escape zone defines a set of states along the current line of sight. When the evading aircraft is located inside the dynamic-escape zone, survivability can be guaranteed by applying optimal kinetic-evasion strategies, which result in outrunning the missile. A method is suggested to calculate the dynamic-escape zone in real-time for online applications. The calculation is based on several conservative assumptions, as well as on knowing the missile and aircraft parameters. Simulations are used to demonstrate the eff...

Robust missile longitudinal autopilot design based on equivalent-input-disturbance and generalized extended state observer approach

Abstract: This paper presents a new robust design for the longitudinal autopilot of a tail-controlled, skid-to-turn missile based on equivalent-input-disturbance (EID) and generalized extended state observer (GESO) approach. Firstly, the nonlinear missile longitudinal dynamics is modeled as a linear formulation for angle-of-attack tracking with uncertainties and disturbances. Next, as a new method, EID-GESO-based control is proposed for disturbance rejection. The method regards the uncertainties and disturbances as a lumped disturbance, named as EID, and simultaneously attenuates it through estimation of linear GESO and simple feedback. Closed-loop stability of the method is also proved. The most important feature of the proposed method over the others is that there is no requirement for system transformation, differentiation of the measured output, full system state available, exact plant model or any information about uncertainties and disturbances. Subsequently, the method is applied to robust longitudinal autop...

Radio-Transparent Ceramics: Yesterday, Today, Tomorrow

Abstract: The physico-technical properties and features of production of several radio-transparent ceramics are examined in connection with the tactical-technical characteristics of modern missile weaponry. It is convincingly shown that no single material can satisfy all of the requirements which missile radomes must meet under varying service conditions. An attempt is made to determine the levels that radome materials’ property indices must reach and to identify the technological, materials-science, and design problems that need to be addressed in order to significantly improve the tactical-technical characteristics of different missile systems.

Sight line based finite time convergence active defense guidance control method

Abstract: The invention provides a sight line based finite time convergence active defense guidance control method, relates to a guidance control method, in particular to an active defense guidance control method, and aims at solving the problem that a defensive missile is limited in overload capacity. The sight line based finite time convergence active defense guidance control method comprises the steps of firstly modeling relative motions of a target, the defensive missile and an intercept missile, adopting a sight line guidance mode to design a guidance rule for the defensive missile, then adopting a nonsingular terminal sliding mode to control the designed guidance rule, respectively defining sliding mode variables (shown in the description) of a longitudinal plane and a lateral plane, performing derivation on the sliding mode variables, substituting relative motion equations of the target, the defensive missile and the intercept missile into the variables and obtaining the guidance rule (shown in the description) of the longitudinal plane and the guidance rule (shown in the description) of the lateral plane through compilation, and controlling the missiles according to the guidance rules. By means of the sight line based finite time convergence active defense guidance control method, overload needed by the defensive missile can be effectively reduced. The sight line based finite time convergence active defense guidance control method is suitable for active defense guidance control.

Improving two axes gimbal seeker performance using cascade control approach

Abstract: One of the most important components constituting a homing guided missile is the seeker which basically consists of a detector with a servo-tracking loop. The performance of gimbal seeker is evaluated according to the line of sight (LOS) stability. The purpose of this paper is to present, investigate, and analyze the performance of two axes gimbal seeker which must strictly isolate the LOS from the torque disturbances and missile vibrations. The equations of gimbals motion are derived using Lagrange equation considering the missile angular motion and gimbals mass unbalance. The stabilization loop is constructed by identifying its components, then the traditional and cascade loops are defined. The overall control system is built considering the cross coupling unit and simulated in MATLAB for the traditional and cascade control loops. A comparison study is carried out to investigate the gimbal seeker performance under different operational conditions such as missile rates and accelerations. The simulation r...