Missile

About: Missile is a research topic. Over the lifetime, 12829 publications have been published within this topic receiving 94307 citations. The topic is also known as: guided missile & missiles.

An Optimum Policy for Detecting a Fault in a Complex System

Abstract: Consider a complex system consisting of N modules containing n(1), …, n(N) items or sub-circuits. A very simple device of this nature, for example, would be a hi-fi set, where the amplifier, the cartridge, the speaker(s) and the turntable could be considered to be the modules, and the various parts of each as the basic items in which faults could occur. A more realistic application of the results obtained might be to a radar-missile system, in which surveillance radar, tracking radar, communications system, computer, missile launcher and missile, or parts of them, represent the modules. When the system breaks down, the procedure for detecting the breakdown and hence repairing the system will determine the time taken to repair it. Assuming two different possible models, equations are developed for the optimum policy, i.e., the policy which minimizes the expected amount of time consumed or penalties paid, and these equations are solved for the first model. Model I assumes that over-all tests of each module ...

Missile autopilot design : gain scheduling and the gap-metric

Abstract: This paper presents a systematic methodology for the synthesis of global gain-scheduled controllers for nonlinear time-varying systems. A controller of this type is used to compute the pitch-axis autopilot of an air-air missile. The missile model used is considered a benchmark for testing autopilot controllers in the academic and industrial communities. The missile's dynamics are linearized at a small set of operating points for which proportional― integral/proportional-type controllers are designed, to shape the frequency response of the linear plants' dynamics. A new set of operating points is computed afterward using the connection between the gap metric and the H ∞ loop-shaping theory. Then, reduced-order, static, H ∞ loop-shaping controllers are designed for this set of points using linear matrix inequality optimization techniques. Finally, the global gain-scheduled controller is obtained by interpolating the proportional―integral/proportional and the loop-shaping controllers' gains over the missile's flight envelope. The simulation results given show the generality and effectiveness ofthe proposed control strategy in terms of the operating point selection, stability, performance and robustness, of the closed loop.

Integrated Sliding Mode Guidance and Control for Missile with On-Off Actuators

Abstract: A sliding mode controller was recently introduced for integrated guidancecontrol loops of agile missiles. The sliding surface was chosen to be the zeroeffort miss-distance. The current work extends this result to address nonlinear on-off actuators commonly used in such interceptors. The performance of the integrated design is compared with a two-loop design, i.e., separate guidance and autopilot loops. The simulation includes a detailed pneumatic model of the aerodynamic surface actuators. Compared to the results obtained with a linear first order actuation system, it is shown that the advantages of the integrated design are more significant when tested with the on-off actuator. The proposed integrated algorithm is effective especially for the endgame phase of the interception. However, its high interception accuracy can be attained only if engaged from a limited range of initial conditions within the so called region of attraction, thus posing performance requirements to the midcourse guidance system. The paper presents the regions of attraction for a sample interception setup.

The alignment of ship launched missile IN systems

Abstract: The author outlines the requirements for on-board inertial navigation systems in the next generation of tactical missiles. The significance of alignment accuracy in the performance of such missile systems is discussed, drawing attention to the physical processes which introduce alignment error in a ship launched missile. Two different techniques which may be used to alleviate the problems of alignment inaccuracy are discussed. The first method involves the use of shipboard inertial measurements to carry out an alignment prior to launch. Such methods are strongly dependent on ship motion. The second method involves tracking the missile with the ship's radar and the use of the radar measurements to aid the missile navigation system during flight. The author outlines the integration of the different measurements, the algorithms needed to implement each scheme and concludes with a comparison of the relative merits of shipboard and in-flight alignment.

Unified approach to missile guidance laws: a 3D extension

Abstract: Since the proportional navigation guidance law was first introduced, many of the researchers had proposed different methodologies to investigate the corresponding performances of all the existing guidance laws. Even though a unified approach was proposed a few years ago, other authors found that under the proposed framework, all the existing guidance laws, namely ideal proportional navigation (IPN), true proportional navigation (TPN), and pure proportional navigation (PPN), were indeed special cases of the mentioned general guidance law. However, the results were restricted to two-dimensional space. In this paper, the author not only extends the results to three-dimensional space, but also to general IPN (GIPN), general TPN (GTPN), and PPN. Unlike conventional researchers, a modified polar coordinate (MPC) is adopted. It is shown that with the property of this MPC, for the line of sight (LOS) based guidance laws (GIPN and GTPN) the number of differential equations required to fully describe the relative dynamics can be reduced from six to three, however, for the missile's velocity-based guidance law, i.e., PPN, five differential equations are required. All the terms of differential equations involve only products and additions of variables. For all the mentioned guidance laws in this paper, only two transformed variables are required to describe the capture region, while the third variable is required to provide the condition of finite turn rate.