Design and Simulation of TF and TA Controller for Missile

A nonlinear terrain following(TF) and terrain avoidance(TA) controller is proposed for missile control systems. Based on classical TF algorithm (adaptive angle method), a new method for TF controller is proposed by using angle of attack. A method of obtaining terrain outline data from digital elevation map (DEM) for TF control is discussed in order to save store space. A TA algorithm is proposed by using bank-to-turn technique. The block control model, which is suitable for backstepping design, is given for nonlinear model of missile. Making full use of the characteristics of the system and combining block control principle and backstepping technique, a robust controller design method is proposed. Uncertainties in every sub-block are allowed, and can be canceled by using the idea of nonlinear damping. It is proved that the state tracking errors are converged to a neighborhood of the origin exponentially. Finally, nonlinear six-degree-of-freedom simulation results for the missile model are presented to demonstrate the effectiveness of the proposed control law.     

Numerical Analysis of 3 mm Ferrite Dielectric Waveguide Through Galerkin＇s Method

With the development of long range missile early warning radar, MMW phased array antenna is strongly needed. The phase shifter （PS） with high power capability and low insertion loss is a key technology in this kind of radar. Ferrite dielectric waveguide is introduced in this paper to manufacture PS, the cross section can be enlarged to 4 times of that of the conventional PS, which facilitates the engineering realization with reduced insertion loss. A novel vector base function of Galerkin method is proposed in calculating the eigenvalue of ferrite dielectric waveguide. The field distribution of main mode, power density and efficiency of 94 GHz difference phase shifter are also given.     

Penetration Capability Comparison of the Same Anti-ship Missiles Between Millimeter and Centimeter Wave Seekers

This paper compares the penetration capabilities of the same type anti-ship missiles with millimeter wave （MMW） seeker and centimeter wave seeker, and constructs mathematical models of penetration probability and saturation attack number for all anti-ship missiles used in the countermeasure system, according to the rule which makes the shipborne air defence system oppase as far as possible and equally, and combining the actual combat situation. It can be seen, from analysis of the countermeasure process between anti-ship missile and surface naval ship, that for the same type of anti-ship missile with different seekers, the main influence on the penetration capability is from electronic jamming system. Based on the built model, the penetration capabilities of the same type anti-ship missiles with MMW and centimeter wave seekers are simulated. The simulated results show that the penetration capability of MMW seeker is slightly better than that of the centimeter wave seeker and its saturation attack number is also influenced by the discovering probability greatly. Finally, some suggestions to get superior penetration effect are given for a commander to choose seeker type suitably.     

Study on Calculating Blockage Probability and Entry Angle Error of Intelligence Missile to Runway

The blockage effectiveness problem for the runway cut-blanked modes of intelligence missile is described using probability integral method, when entry angle error and open cabin position error exist. On the condition of determined open cabin position error, the allowable range of entry angle error is inversely calculated with interdiction probability. The calculated results indicate that the method mentioned can estimate the intelligence missile interdiction efficiency to the runway and the range of entry angle error, which provides available basis for analyzing the intelligence missile attack assignment on the way.     

Real-time Extraction of Target Position Information Based on Bi-orthogonal Wavelets

Extraction of flying target position information is the prerequisite for passive infrared guided missiles to track the target. The existing missile detection system senses the target＇ s infrared radiation, and then the generated signal is sent to signal processing circuits for extracting the target position information. In order to improve anti-interference capacity of the detection system, an algorithm of module maximum edge detection based on the bi-orthogonal wavelets is proposed to replace its hardware. The signal can be decomposed in one layer, only its high frequency detail is reconstructed. After some calculations, the average target position can be obtained. The algorithm＇s real-time implementation with DSP is also discussed. To reduce the execution time, the program structure can be optimized with double buffers in memory. This im- plementation is verified by simulations. The results show that the method has only a small amount of calculations, can meet the requirements for finding out the target position in real-time and needs not the traditional processing circuit.     

Study on Anti-ship Missile Saturation Attack Model

Based on the analysis for the interception process of ship-to-air missile system to the anti-ship missile stream, the antagonism of ship-to-air missile and anti-ship missile stream was modeled by Monte Carlo method. This model containing the probability of acquiring anti-ship missile, threat estimation, firepower distribution, interception, effectiveness evaluation and firepower turning, can dynamically simulate the antagonism process of anti-ship missile attack stream and anti-air missile weapon system. The anti-ship missile's saturation attack stream for different ship-to-air missile systems can be calculated quantitatively. The simulated results reveal the relations among the anti-ship missile saturation attack and the attack intensity of anti-ship missile, interception mode and the main parameters of anti-air missile weapon system. It provides a theoretical basis for the effective operation of anti-ship missile.     

Feasibility analysis of WDM links for radar applications

Active phased array antennas enhances the performance of modern radars by using multiple low power transmit/receive modules in place of a high power transmitter in conventional radars. Fully distributed phased array radars demand the distribution of various signals in radio frequency(RF) and digital domain for real time operation. This is normally achieved through complex and bulky coaxial distribution networks. In this work, we intend to tap the inherent advantages of fiber links with wavelength division multiplexed(WDM) technology and a feasibility study to adapt these links for radar applications is carried out. This is done by analysing various parameters like amplitude, delay, frequency and phase variation response of various radar waveforms over WDM links. This also includes performance evaluation of non-linear frequency modulation(NLFM) signals, known for better signal to noise ratio(SNR) to specific side lobe levels. NLFM waveforms are further analysed using pulse compression(PC) technique. Link evaluation is also carried out using a standard simulation environment and is then experimentally verified with other waveforms like RF continuous wave(CW), pulsed RF and digital signals. Synchronization signals are generated from this variable duty cycle digital signals during real time radar operation. During evaluation of digital signals, variable transient effects for different duty cycles are observed from an amplifier configuration. A suppression method is proposed to eliminate this transient effects. Further, the link delay response is investigated using different lengths of fiber spools. It can be inferred from the experimental results that WDM links are capable of handling various signals significant to radar applications.     

A Rapid Method for Compensating Output Error of Electromagnetic Tracker

Some methods which use an optical tracker （OT） as a standard reference of electromagnetic tracker （EMT） were proposed in order to compensate the output error of electromagnetic tracker. Usually, they use a magneto-optic tool to collect the outputs of OT and EMT simultaneously, and then compare the output of OT with that of EMT to compensate the error of EMT. Although the outputs of EMT and OT can be matched each other by using a time stamp which denotes when the acquirement command is sent, but the accuracy will decrease if the tool moves faster for the errors of the time stamp itself. A rapid method for compensating EMT output error is proposed. A particular scan mode of the magneto-optic tool is designed for collecting EMT and OT outputs, and a data registration method is proposed to match the outputs of EMT and OT. The simulated results show that the output error of EMT can be decreased efficiently and the accuracy of the compensation can be improved by about 15 % compared with that of the existing methods.     

Passive Target Tracking in Non-cooperative Radar System Based on Particle Filtering

We propose a target tracking method based on particle filtering（PF） to solve the nonlinear non-Gaussian targettracking problem in the bistatic radar systems using external radiation sources. Traditional nonlinear state estimation method is extended Kalman filtering （EKF）, which is to do the first level Taylor series extension. It will cause an inaccuracy or even a scatter estimation result on condition that there is either a highly nonlinear target or a large noise square-error. Besides, Kalman filtering is the optimal resolution under a Gaussian noise assumption, and is not suitable to the nonGaussian condition. PF is a sort of statistic filtering based on Monte Carlo simulation that is using some random samples （particles） to simulate the posterior probability density of system random variables. This method can be used in any nonlinear random system. It can be concluded through simulation that PF can achieve higher accuracy than the traditional EKF.     

Using Fractional-order PI^λD^μ Controller for Control of Aerodynamic Missile

A new type of PID controller is introduced and .some properties are given. The novelty of the proposed controller consists in the extension of derivation and integration order from integer to non-integer order. The PI^λD^μ controller generally has three advantages when compared to the integerl-order controller： the first is that it has more degrees of freedom in the model; the second is that it has a memory in model, the memory insure the history and its impact to present and future, the third is it ensures the stability of missile. This approach provides a more flexible tuning strategy and therefore an easier achieving of control requirements. Flight dynamic model of an aerodynamic missile is taken into account in implementing the PI^λD^μ controller. Simulation results show that the PI^λD^μ controller is not sensitive to the changes of control parameters and the system parameters. Also, the controller has more flexible structure and stronger robustness.     

多级涡轮级间燃烧室发动机与常规涡轮喷气发动机性能对比研究

为了对比分析多级涡轮级间燃烧室发动机和常规涡轮喷气发动机性能,文中分别计算分析了多级涡轮级间燃烧室发动机和常规涡轮喷气发动机性能参数的变化规律,并对配装相同参数的多级涡轮级间燃烧室发动机和常规涡轮喷气发动机的某型超音速导弹进行了飞行性能模拟。结果表明:多级涡轮级间燃烧室发动机具有比常规涡轮喷气发动机更大的推力和更高的Ma数飞行范围。与常规涡轮喷气发动机动力装置相比,配装多级涡轮级间燃烧室发动机的某型超音速导弹沿给定的飞行轨迹飞行时,加速度更大,飞行时间更短,剩余质量比更高,巡航距离更长,飞行性能优势明显。     

超声速巡航导弹速度控制系统设计

为解决超声速巡航导弹速度控制系统存在的参数时变、不确定干扰问题,设计了一种反演鲁棒控制律。在巡航导弹的动力学模型中考虑固体冲压发动机的工作特性,分析并建立了超声速巡航导弹速度控制系统数学模型; 采用反演算法推导了虚拟期望推力值,并基于Lyapunov理论设计了具有鲁棒性能的速度控制律。以某超声速巡航导弹为例,设计反演鲁棒控制律,并与传统PID控制进行对比分析,仿真结果表明,速度控制系统能够快速、准确地跟踪速度指令且具有较强的鲁棒性。     

自适应Kalman滤波在巡航导弹航迹融合中的实现

针对巡航导弹航迹的融合与滤波问题,提出改进Kalman线性滤波算法的一种思路与方法。巡航导弹航迹融合模型包括飞行动态模型、探测器观测模型、Kalman滤波算法模型、坐标转换及转换后方差的近似计算方程等。这种改进算法基于转向判定域调整滤波初值,给出算例并对相关计算数据进行了简要地分析与评价。实验表明,这种改进算法精确有效。     

近程防空导弹拦截巡航导弹的建模与仿真

为有效提高导弹的杀伤能力,对近程防空导弹拦截巡航导弹进行建模与仿真。对近程防空导弹武器系统的探测和杀伤区进行分析,计算导弹的发射区。根据防空导弹的导引规律,建立对巡航导弹的拦截模型,根据导弹的杀伤区、搜索跟踪雷达对目标的发现距离等计算出导弹的发射区。利用MATLAB进行仿真,计算拦截次数、每次拦截时目标距离发射阵地的距离及拦截总时间,并根据不同的杀伤区,对导弹速度与拦截次数的关系进行仿真。该方法具有一定的通用性,可为提高导弹战术技术性能提供参考。     

一种基于倒三角形的地形回避算法

针对基于激光前视雷达的巡航导弹在巡航阶段实现自主地回避地形障碍物这一课题，在地形回避算法中，提出了飞行矢量三角形的概念．通过求解激光前视雷达视场中各地形点的代价函数，找出最适合放置飞行矢量三角形的地形点，从而确定地形回避导航点，大大简化了在雷达视场中获得地形回避导航点的计算过程．通过仿真，验证了该算法简单快速，能及时获取雷达视场中的回避导航点，为导弹实现自主回避飞行提供了可行性保障。     

巡航导弹航迹规划决策系统研究与开发

在研究巡航导弹任务规划的基础上,采用TF/TA2（Terrain Following/Terrain Avoiding/Threat Avoiding）技术,利用地球曲率和地形起伏而造成的防空体系的盲区,使导弹进行超低空飞行,达到突防目的.并设计了巡航导弹航迹规划决策系统,包括地形模拟、航迹决策、雷达辐射源库、火力威胁库的建立和最优航迹算法研究等.     

雷达对抗GPS制导系统初探

全球定位系统（GPS）在现代战争中成为重要的导航和制导手段，雷达阵地面临装有GPS制导系统的反辐射导弹和巡航导弹的威胁。分析GPS频率、能量、时域及波形等特性，探讨GPS信号的侦测、GPS干扰技术体制、GPS分布式立体干扰系统的建立，并得出有益的结论。     

不同速度导弹的声辐射特性研究

根据悬浮子弹药对导弹的末端拦截所需的起爆激励条件,研究了导弹飞行过程中的声辐射特性。利用COMSOL Multiphysics多物理场仿真软件对亚声速、跨声速和超声速3种速度等级导弹飞行过程中的表面脉动压力进行了仿真,得到了导弹周围的压力分布及其表面最大脉动压力随速度的变化关系。依据气动声学的声学相似理论对亚声速导弹所产生的声场进行了仿真,分析了该辐射声场中各参量的变化。结果表明:高频单色波可以作为悬浮子弹药激爆检测信号,研究结果可应用于悬浮子弹药声光激爆机制的设计。     

面向21世纪飞航导弹总体设计思想探讨

分析了飞航导弹传统设计思想的不足 ,提出了六种类型飞航导弹武器系统的发展模式 .指出了 2 1世纪飞航导弹总体设计思想需要转变 ,以适应日新月异的科技进步和未来武器发展需求 ,提高飞航导弹总体设计水平     

巡航导弹中制导精度分析与仿真

对于中远程巡航导弹来说,中制导段的飞行时间长、距离远,是巡航导弹完成任务的关键。本文以假想的巡航导弹设计为背景,对影响巡航导弹中制导精度的各种因素进行分析,最后通过仿真得到了相关的误差模型。这项工作,为巡航导弹中制导的设计提供了参考依据。