Missile Control Research Articles

Experimental investigation of side jet interaction with a supersonic cross flow

The following paper reports on experimental investigations on high-speed missile control. The paper looks especially at the interference effects of side jets with supersonic cross flow. Detailed wall pressure measurements are presented for three different jet configurations. The shock structure is shown with Schlieren images and the wall streamlines are visualised with oil flow technique.

Model for simulating the flight control system of a antiship missile

The paper analyzes a program for simulating the flight control of an antiship missile with the radar seeker. The paper analyzes a mathematic missile model an autopilot model and a target model. Thus obtained results enable a more realistic process of flight tracking of a particular antiship missile as the missile guidance along the whole trajectory provides many advantages over unguided projectiles, primarily because of the possibility to fire at moving targets. The flight control simulation model enables further study of this missile class.

Fuzzy side force control for missile against hypersonic target

An integrated fuzzy-logic-based missile side force control mechanism is proposed for the interception of ballistic targets in three-dimensional space. Stringent scenarios when the missile intercepts the ballistic target at higher attitudes are considered. Conventional guidance systems with the aerodynamically controlled mechanism alone are usually incapable of engaging a high-speed target at low-air-density layers. To overcome the difficulty because of insufficient manoeuvrability, a fuzzy side force control scheme configured with two additional auxiliary thrusters is proposed to generate extra transverse acceleration and thereby to reinforce the engagement performance. A simulation study proves the effectiveness of the proposed approach.

SDRE AUTOPILOT FOR DUAL CONTROLLED MISSILES

The SDRE technique is used to develop an autopilot design for a dual controlled (tail and canard) missile. Dual control missiles can have difficulty achieving high angles of attack and thus high levels of lateral acceleration because the control surfaces move together to achieve quick responses but in steady state the deflections can be significantly larger than with only one control. The unique contribution of this paper is examining the effects of scheduling the design weights on state variables to solve this specific problem with dual controlled missiles. Output and control weights having dependence on the state variables are examined to overcome this problem.

Pragmatic Micawberism? Norm Construction on Ballistic Missiles

Ballistic missile and WMD proliferation go hand-in-hand, yet missile norms remain the most chronically under-developed of all the international arrangements surrounding WMD. This article argues that although the link between missiles and WMD undoubtedly is important, it should not be overplayed when trying to establish norms and controls over international missile proliferation. Ballistic missile control will certainly reinforce international controls over WMD, but will need to be constructed on a different set of principles. It no longer is sufficient waiting, as if for something to turn up. Nonetheless, there is a way forward, one that requires a pragmatic deference to existing realities, but tempered with a certain optimism that the way chosen will produce results in the long term rather than immediately. Bans are infeasible, but control may result from a process of patient construction, including such elements as regional agreements and a shift to missile defence.

Integrated Guidance and Control of Missiles With$theta hbox - D$Method

A new suboptimal control method is proposed in this study to effectively design an integrated guidance and control system for missiles. Optimal formulations allow designers to bring together concerns about guidance law performance and autopilot responses under one unified framework. They lead to a natural integration of these different functions. By modifying the appropriate cost functions, different responses, control saturations (autopilot related), miss distance (guidance related), etc., which are of primary concern to a missile system designer, can be easily studied. A new suboptimal control method, called the thetas-D method, is employed to obtain an approximate closed-form solution to this nonlinear guidance problem based on approximations to the Hamilton-Jacobi-Bellman equation. Missile guidance law and autopilot design are formulated into a single unified state space framework. The cost function is chosen to reflect both guidance and control concerns. The ultimate control input is the missile fin deflections. A nonlinear six-degree-of-freedom (6-DOF) missile simulation is used to demonstrate the potential of this new integrated guidance and control approach

Computational Investigation and Design Optimization of a Lateral-Jet-Controlled Missile

To investigate the behavior of normal force and pitching moment characteristics for different angles of attack and spouting jet angles, a parametric study of a lateral-jet-controlled missile has been performed. For this purpose, a three-dimensional Navier-Stokes computer code, AADL3D, has been developed and validated. Based on results of the parametric study, pitching moment and normal force coefficients have been selected as the objective and constraint functions, respectively. The flight Mach number, the angle of attack, and the spouting lateral jet angle are the design variables. With implementation of a genetic algorithm for the global optimum and the response surface method, the design optimization of the lateral-jet-controlled missile has been performed to evaluate the most effective flight conditions for the missile control.

Polynomial approach for design and robust analysis of Lateral missile control

A polynomial approach is presented for the design and analysis of a sideslip velocity missile autopilot. The controller is designed using polynomial eigenstructure assignment (PEA). The missile model is described by linear parameter varying (LPV) matrices. The design renders to a closed-loop system independent of the choice of equilibria. Thus, if the operating points are in the vicinity of the equilibria, then only one linear model will describe closed-loop dynamics, regardless of the rate of change of the operating points. Parametric stability margins for uncertainty in the controller parameters and aerodynamic derivatives are analysed using a finite version of the Nyquist Theorem. The Finite Nyquist Theorem (FNT) exploits the polynomial framework to assess robustness for a parametric uncertain system with the Finite Inclusion Theorem (FIT). The design and analysis approach is applied to a single-input single-output (SISO) tail-controlled missile in the cruciform fin configuration. Simulations show good tracking of sideslip velocity with closed-loop system, fast responses and good parametric robustness against six uncertain parameters.

Signal reconfiguration of missile fault-tolerant control

To improve the reliability of missile control systems and to prevent self-destruction caused by faulty inertia sensors, a novel approach of fault-tolerant control with signal reconfiguration is proposed. The rigid body angle signals and the different-order elastic oscillation-caused angle signals are first separated from output signals of the inertia sensors with signal processing. Then, the relationship between the elastic oscillation of the missile body and the attitude angles and the relationship among the output signals of the sensors are analysed. Finally, the normal signal of a faulty sensor is reconfigured with the output signals of other normally working sensors via analytical redundancy. Some examples are provided to illustrate the main results.

Numerical investigation of the shock interaction effect on the lateral jet controlled missile

A computational study on the supersonic flow around the lateral jet controlled missile has been performed. A three-dimensional Navier–Stokes computer code (AADL 3D) has been developed and case studies have been performed by comparing the normal force coefficient and the moment coefficient of a missile body. Different jet flow conditions including jet pressures and jet Mach numbers, and the circumferential jet positions have been incorporated into the case studies. The missile surface is divided into four regions with respect to the center of gravity, and the normal force and moment distribution at each region are compared. The results show conspicuously different normal force and moment variations according to each parameter variation. From the detailed flow field analyses, it has been verified that most of the normal force loss and the pitching moment generation are taking place at the low-pressure region behind the jet nozzle. Furthermore, it is shown that the pitching moment can be efficiently reduced by the lateral thrust obtained through higher jet Mach number rather than high jet pressure. Thus, an angle of yaw is more effective for missile control by side jet than an angle of attack.

Control and Maneuverability of a Square Cross-Section Missile

A study has been conducted into the aerodynamics, control, and performance of a square cross-section supersonic missile. Comparisons have been made with an equivalent circular cross-section baseline. This paper summarizesthe control and maneuverability findings and explores the relationship between airframe asymmetry and autopilot architecture. Missile autopilot designs based on classical, H ∞ , and nonlinear dynamic inversion methodologies are compared in terms of a robust stability requirement defined by Nichols exclusion regions, applied in a multiloop sense. Valuable insights into the required autopilot architecture are gained through this. Various other performance metrics are also proposed and used to explore the relative merits of the square cross-section body shape.

Fault diagnosis of inertia sensor in missile control systems

Fault diagnosis of inertia sensor in missile control systems

Fault diagnosis of inertia sensor in missile control systems

Because the magnitude of each order of oscillation signals in the yaw and roll channels of missile control systems varies with various influences, it is impossible to diagnose faults in the sensors of these channels using modelbased fault diagnosis. Based on the characteristics of the systems, a method of fault diagnosis with adjacent wavelet coefficient algorithm is given. Further, based on the difference between the characteristics of the Mallat wavelet coefficients and that of Coilflets wavelet, different algorithms are given. Then, thresholds can be properly selected and abrupt faults diagnosed. A method to diagnose disconnection or short circuit faults is also proposed according to the zone of the current and the zone of voltage when the fault occurs gradually. The combination of these two methods effectively solves fault diagnosis problems of sensors in missile control systems.

Turbulence Model Studies to Investigate the Aerodynamic Performance of a NASA Dual Control Missile at Supersonic Mach Numbers

This paper contains an investigation of the ability of some of the current turbulence models to predict viscous effects in supersonic Mach number regimes. In most cases, these turbulence models have been derived and validated in traditional subsonic to transonic Mach number regimes and their application to supersonic and hypersonic regimes is assumed valid without a proper recourse to understanding the wider implications of the viscous flow field at high Mach numbers. In such flow regimes, such characteristics as the strong shock interactions with control surfaces and evolving vortices present in the flow, or other large entropy gradient effects brought about by the forebody or other fin surfaces, produce non-trivial challenges for the turbulence models. This study was aimed at interrogating the strength of the turbulence models to model such physics. The Applied Vehicle Technology Panel Group 082 of the Research Technology Organisation selected a dual control NASA missile to investigate the capabilities of Computational Fluid Dynamics (CFD) to predict the flow field and performance characteristics of complex-shaped projectiles at high Mach numbers. There are two types of difficulties that are encountered when computing such problems. The first type are geometry based, and are related to the shape of the nose and forebody, number and types of strakes or forward control mechanisms, fin geometry deployment, and shape and design of the cowls and intakes. The second type of difficulty deals with flow complexities such as the heat transfer (M > 4) implications; the vortices shed from the forebody and other control surfaces; the interaction of these vortices with the body structures, the free stream, and with each other; the base flow interaction with the free stream; the boundary-layer development; and, in the case of supersonic flows, the shock boundary-layer interactions. Air-breathing missiles with intakes or missiles with jet-controlled guidance systems add to the flow complexities. Various turbulence models employed in current CFD codes are tested for their ability to address these viscous issues.

An integrated design and optimization environment for industrial large scaled systems

The objective of this paper is to demonstrate how a combination of design optimization theory and methodology can be applied to large-scaled industrial systems to efficiently improve their performance, reduce their costs or improve other design objectives. The scheme described was developed when other conventional design and optimization strategies failed in efficiently optimizing an air-to-air missile design for Lockheed Martin Missile and Fire Control. The efficient design scheme was developed for the system using a combination of optimization and design of experiment techniques. It will be shown that multidisciplinary design optimization techniques can be improved with a dependency-tracking demand-driven language resulting in an attractive choice for solving industrial type design problems. The design methodology holds true even for systems in which a large number of disciplinary design and analysis software are integrated. One reason for the efficiency of the scheme is the parameterized dependency-tracking environment in which the optimizations are carried out. With the hybrid approach developed, combining exploration and optimization techniques with the unique dependency-tracking and demand driven features of the environment, it was possible to reduce the computational time by as much as 44%. The design scheme developed and presented can be used to improve the design and optimization process for numerous other engineering applications.

A passivity perspective for the synthesis of robust terminal guidance

This note proposes a robust guidance synthesis based on the passivity approach. The method is applied to missiles whose flight control dynamics are modeled as linear uncertain systems with bounded uncertainties. The robust guidance laws are obtained by means of an appropriate subsystem decomposition, providing passivation by feedback and feedforward control. Hence, L/sub 2/ stability of the missile-target closed-loop system is warranted by direct application of the passivity theorem. The resulting terminal guidance laws ensure robust stability of the null miss distance in the case of 1) a maneuvering target whose acceleration lies in L/sub 2/, and 2) bounded parametric uncertainties of second-order models of the missile flight control dynamics. Numerical simulations demonstrate the effectiveness of the proposed guidance laws.

Passive Control of Plume Interference on Slender Axisymmetric Bodies

The physics of the plume-induced shock and separation, particularly at high plume to exit pressure ratios with and without shock-turbulent boundary-layer control methods, were studied using computational techniques. Mass-averaged Navier-Stokes equations with a two-equation turbulence model were solved by using a fully implicit finite volume scheme and time.marching algorithm. The control methodologies for shock interactions included a porous tail and a porous extension attached at the nozzle exit or trailing edge. The porous tail produced a weaker shock and fixed the shock position on the control surface. The effect of the porous extension on shock interactions was mainly to restrain the plume from strongly underexpanding during a change in flight conditions. These techniques could give an additional dimension to the design and control of supersonic missiles.

부구조물 합성법을 이용한 접는 미사일 조종날개 모델 수립

A deployable missile control fin has some structural nonlinearities because of the worn or loose hinges and the manufacturing tolerance. The structural nonlinearity cannot be eliminated completely, and exerts significant effects on the static and dynamic characteristics of the control fin. Thus, It is important to establish the accurate deployable missile control fin model. In the present study, the nonlinear dynamic model of 4he deployable missile control fin is developed using a substructure synthesis method. The deployable missile control fin can be subdivided Into two substructures represented by linear dynamic models and a nonlinear hinge with structural nonlinearities. The nonlinear hinge model is established by using a system identification method, and the substructure modes are improved using the Frequency Response Method. A substructure synthesis method Is expanded to couple the substructure models and the nonlinear hinge model, and the nonlinear dynamic model of the fin is developed. Finally, the established nonlinear dynamic model of the deployable missile control fin is verified by dynamic tests. The established model is In good agreement with test results, showing that the present approach is useful in aeroelastic stability analyses such as time-domain nonlinear flutter analysis.

Robust control of the missile attitude based on quaternion feedback

In this paper, a robust control scheme based on the quaternion feedback for attitude control of missiles employing thrust vector control is proposed. The control law consists of two parts: the nominal feedback part and an additional term for ensuring robustness to the plant uncertainties. For the proposed control scheme, a stability analysis is given and the performance is shown via computer simulation.

A multi-objective control approach for the synthesis of robust digital guidance laws

This paper proposes a new approach for the synthesis of robust digital guidance laws with the objective of achieving stable and accurate missile guidance despite parametric uncertainties in the missile flight control system dynamics, prescribed limits on missile acceleration, and digital implementation at possibly slow sampling rates. The proposed approach is characterized by two consecutive steps. Firstly, a robust continuous-time guidance law is designed using mixed H2-H∞ minimization and pole placement such that the effects of noise and parametric uncertainties are attenuated. To carry out this first step of the approach, missile flight control dynamics are modelled as second-order interval transfer functions, where bounded time-varying parameters characterize the missile flight envelope. Secondly, digital redesign of the robust continuous-time missile control system (including guidance and flight control) is performed by solving an optimal control problem. The proposed global digital redesign strategy results in robust performance for the closed-loop sampled-data missile control system for a wider range of sampling rates than those obtained with currently available approaches and can be readily implemented on commercially available software by following the step-by-step procedure described in the paper. Numerical simulations consisting of a missile pursuing a manoeuvring target, described by the so-called Singer model, demonstrate the effectiveness of the proposed approach.