基于H∞控制理论的某型导弹自动驾驶仪设计与仿真

研究了导弹制导回路鲁棒自动驾驶仪设计的理论与方法,并结合某型导弹进行了混合灵敏度自动驾驶仪的设计及仿真.仿真结果表明,设计的混合灵敏度自动驾驶仪对导弹模型的摄动表现出了较强的鲁棒性,可以控制导弹在大范围飞行过程中稳定且具有良好的时域响应性能.     

高性能防空战术导弹从优定向控制的现状和有关问题

本文提供了关于采用从优定向控制的防空战术导弹的自动驾驶仪发展现状概况,并指明有关影响稳定和控制特性的关键耦合回路和参量。一般说来,由于横向通道动力学耦合回路的增强,经典的侧滑一转弯自动驾驶仪体制限制了从优定向控制结构的应用可能性。仔细设计导弹弹体可以稍微缓和一下这一问题,但是,为了使性能达到最优,可能还需要改进自动驾驶仪的性能。还提出了与研制自动驾驶仪和具有期望特性的弹体结构有关的技术问题。     

基于ATS的导弹稳定回路半实物仿真系统设计

根据当前导弹自动驾驶仪测试现状,提出了一种基于导弹驾驶仪自动测试系统的控制稳定回路半实物仿真系统方案,利用虚拟仪器技术和PXI总线技术,组建高精度、多用途、具有自诊断功能的测试和仿真系统,它既能够实现对自动驾驶仪的综合测试,又能验证导弹控制律的优劣.系统基于模块化设计,具有良好的通用性和很强的可扩展性,能够完成不同型号导弹的测试和仿真任务.     

基于μ综合的导弹自动驾驶仪设计

为了满足高机动性要求,空空导弹常采用大攻角飞行;然而导弹大攻角飞行时存在通道间耦合严重、气动力系数摄动范围大等问题,使设计模型与实际对象误差严重,传统方法设计的自动驾驶仪很难满足鲁棒性要求.考虑导弹自动驾驶仪设计中存在的未建模误差和气动力系数摄动等不确定性因素,采用μ综合设计方法,以某型导弹为例对其俯仰通道驾驶仪进行了...     

“阿波罗”指挥舱和指挥舱/登月舱飞行器推力矢量控制数字自动驾驶仪

“阿波罗”指挥舱和指挥舱/登月舱飞行器推力矢量控制用的数字自动驾驶仪是由麻省理工学院仪表试验室研制的,这个飞行器的俯仰和偏航是通过将火箭发动机安装在常平架上的办法来控制,而飞行器的横滚则通过点燃控制系统的喷气发动机来控制。 喷气发动机点火用的较简单的相平面开关逻辑线路可以控制飞行器的横滚。但是,对俯仰和偏航的控制,由于飞行器的弹性振动,燃料的晃动,推力不重合以及控制回路的交联影响等一系列问题,需要更精心的设计。 本文阐述了用于研制俯仰和偏航自动驾驶仪的设计途径和分析方法。这种设计具有很多重要的特点,如由宇宙航行员控制的高-低带宽工作状态,时变增益,多种取样速率,用可清除系数实现滤波的广义滤波器,推力不重合校正回路以及双增益控制回路。 本文还说明了这些自动驾驶仪的工作特点和实现方法,并分析了它们的稳定性和控制特性。     

交联耦合对自旋导弹控制系统特性的影响分析

基于小扰动线性化的弹体运动模型,建立了自旋导弹的三回路自动驾驶仪控制模型,得到了复数形式的闭环传递函数。在此基础上,分析了闭环系统的交联特性,结果显示,三回路自动驾驶仪使自旋导弹实现了稳态解耦,且闭环稳态增益不受气动参数变化影响。利用复系数线性多项式稳定性判别方法,研究了自旋导弹的闭环稳定性,分析了交联项对三回路自动驾驶仪稳定裕度的影响情况,得到了系统的闭环稳定条件。     

单通道自旋导弹自动驾驶仪回路的变换及其简化

为了在准弹体坐标系下设计单通道旋转导弹的自动驾驶仪,给出了弹体坐标系下的自动驾驶仪结构,通过旋转变换,将弹体坐标系下的自动驾驶仪回路变换到准弹体坐标系下,仿真结果验证了该变换方法的正确性。对变换后的自动驾驶仪回路进行了简化,忽略两倍弹旋频率交变分量的影响,仿真结果表明了简化的可行性,可用简化后的模型在准弹体坐标系下进行自动驾驶仪设计。     

大攻角飞行空空导弹鲁棒自动驾驶仪设计

当前,导弹自动驾驶仪多采用经典设计方法。是在导弹气动参数变化不大、通道间的耦合较小的情况下设计的。为了满足导弹高机动性能要求,常采用大攻角飞行;然而导弹大攻角飞行时,将会出现空气动力学系数不确定性、非线性和通道间的严重耦合问题,这就要求所设计的自动驾驶仪具有较好的鲁棒性。就导弹在大攻角飞行状态下、通道间解耦的基础上,针对空气动力学系数不确定性,用μ方法对俯仰通道驾驶仪进行了设计,仿真表明该方法具有较好的鲁棒性能。     

导弹自动驾驶仪控制算法鲁棒性研究

以某型轴对称导弹为研究对象,在解耦和线性化的情况下,得到简化的数学模型。通过求解线性矩阵不等式(LMI)设计了状态反馈H∞控制导弹自动驾驶仪,采用模糊和变论域理论设计了变论域模糊PID控制自动驾驶仪。考虑飞行过程中的干扰、气动参数摄动,对两种自动驾驶仪的控制性能进行对比研究,仿真结果表明,二者皆能实现对导弹制导指令的有效跟踪,其中状态反馈H∞控制设计的自动驾驶仪在指令跟踪的快速性、准确性和抗干扰性上具有明显的优越性。     

基于变结构控制的自动驾驶仪设计

自动驾驶仪作为导弹制导控制系统的主要组成部分,是确保导弹在制导飞行中具有良好的稳定性和可控性的关键.而变结构控制以其在一定条件下对干扰和参数变化具有完全自适应的突出优点,在自动驾驶仪中已经有了深入的研究和实际的应用.简要概述了自动驾驶仪的设计难点、变结构在驾驶仪设计中的应用进展,然后针对战术导弹滚转通道设计了两种不同结构的变结构驾驶仪,并进行了仿真、分析比较.     

Helping hands: civil–military cooperation and Italy's military operation abroad

In the Post-Bipolar Era the growing complexity of the military operations requires a new approach for the resolution of international crises. Since the end of the Cold War, peace support operations (PSO) have become the mainstay and principal occupation of most Western armies. At the same time, Italy has been one of the most important actors in such an area. The article focuses on the cooperation between military and civil components (a process called CIMIC) as a key variable in the Italian PSOs. We will analyse in detail the main lessons learned from past military interventions as well as the general context in which new tendencies are taking place. The maintaining of a minimum security frame becomes essential to fulfil activities ‘collateral’ to the mission: reconstructing services and infrastructure, food distribution, water and medication, law and order, de-mining, training of local forces, and supporting local institutions. These are the main tasks to obtain thrust and support from the population.     

Terrorism,insurgency, kidnapping,and security in Africa's energy sector

Energy continues to serve as the bedrock of modern economies and the main driver of modern society. For Africa, the production and supply of energy resources such as crude oil, natural gas, uranium, coal, biomass, biofuels and other renewables are an important source of employment, rents, taxes, royalties and profits. This sector brings in several tens of billions of dollars of revenue annually. The production and delivery of such resources, however, depend on critical infrastructures such as pipelines, refineries, processing plants, terminals, rigs, electrical energy pylons, substations, pump stations, vessels, and tankers. These infrastructures have been attacked by terrorists, insurgents, vandals and saboteurs, all of whom see them as targets against which to register their grievances and extract concessions from the state. This paper is a chronological account of some of the documented incidents of terrorism, insurgency, kidnapping, destruction, sabotage, and human casualties suffered in the oil and gas sectors in Africa between 1999 and 2012. It is based on data extracted from the databases of the RAND Database of World Terrorism Incidents and the University of Maryland's Global Terrorism Database (GTD).     

Tacit support for terrorism: The rapprochement between the USSR and Palestinian guerrilla organizations following the 1967 war

This article demonstrates the inconsistent and wavering Soviet attitude towards national liberation movements in general and the Palestinian organizations in particular. Until the late 1960s, the Soviets viewed these organizations with suspicion, hesitating to engage in political dialogue with them. However, in the 1970s, political and military events in the region, as well as modifications in the Kremlin's Cold War strategies, led to a general shift towards the Middle East in Soviet foreign policy. Soviet leaders showed increased willingness to provide certain Palestinian organizations with arms with which to conduct terrorist activities against Israeli, pro-Israeli, Jewish and Western targets. The article explores the complex relations between Palestinian organizations and the USSR in the field of international terror. The study also exposes and analyzes the nature and content of Soviet–Palestinian arms dialogues and transactions. It provides clear evidence that Soviet policymakers and other luminaries were fully informed of, and sometimes directly involved in, these transactions and dialogues at the highest levels.     

A1 Qaeda and the radical Islamic challenge to western strategy

The September 11 global crisis prompted by the attacks on the World Trade Center and the Pentagon raises major questions concerning the nature and trajectory of terrorism in the post-Cold War global order. Hitherto, terrorism has been largely debated by analysts at the level of nation states. Terrorist and insurgent movements have also been largely anchored in nationalist and ethnic power bases even when they have sought to mobilise a transnational ideological appeal on religious or class grounds. There have been a few exceptions to this pattern such as the alliance between the German Baader-Meinhof group and the Japanese Red Army Faction, but even such international alliances as this did not, until at least the 1980s, presage anything like a global terrorist network necessitating a global strategic response. This study examines terrorism and global strategic responses.     

Reviews

Douglas S. Derrer, We Are All the Target: A Handbook of Terrorism Avoidance and Hostage Survival. Annapolis, MD: US Naval Institute Press, 1992. Pp. x+135, notes, index. $14.95. ISBN 01–55750–150–5

Ian Knight, Zulu: Isandlwana and Rorke's Drift, 22–23 January 1879. London: Windrow & Greene, 1992. Pp.136, 150 illus., incl 8 colour plates, maps, biblio. £35. ISBN 1–872004–23–7

Ian Knight, By the Orders of the Great White Queen: Campaigning in Zululand through the Eyes of the British Soldiers, 1879. London: Greenhill Books and Novato: Presidio Press, 1992. Pp. 272, 17 illus., 1 map. £18.95. ISBN 1–85367–122–3

Manfried Rauchensteiner and Erwin A. Schmidl (eds.), Formen des Krieges: vom Mittelalter zum ‘Low‐intensity’ Conflict’. Graz : Verlag Styria, 1991. Pp.208. DM35. ISBN 3–22–12139–7

Harold J. Kearsley, Maritime Power and the Twenty‐First Century. Dartmouth: Dartmouth Publishing Company, Limited, 1992. Pp.xv + 203, 13 diagrams, index. £32.50. ISBN 1–85521–288–9     

Helping hands: external support for the KNU insurgency in Burma

This article analyses to what extent the Burmese KNU insurgency made use of external support from states, refugees, and diasporas. Based on extensive fieldwork it is concluded that support from neighbouring states and refugees has for years kept the Karen rebellion alive. Western countries perceived forms of resistance to the illegitimate Burmese regime as just and have therefore played a crucial role in the continuation of conflict in Karen State. It is important that policymakers and donors as well as executing organizations continue to reflect critically on the way they exercise their work.     

基于GTST-DMLD-ESD的装备RMS建模仿真

装备的RMS是装备的重要设计参数,是影响战备完好和保障能力的关键因素.引入GTST-DMLD作为主要建模工具,建立起装备系统的RMS描述模型,以ESD为补充和扩展,对维修过程进行建模.并以GTST-DMLD-ESD模型作为装备RMS仿真的核心,对装备RMS仿真模型的总体框架进行了研究,并对各模块进行了较为详细的探讨.     

Panjwai: a tale of two COINs in Afghanistan

The US Army has two approaches to counterinsurgency operations in Afghanistan. One is hard, or combat-focused, and the other is soft, or development-focused. This study examines two US Army task forces deployed to Panjwai District, Afghanistan from 2012 to 2013. CTF 4-9 and 1-38 offer a meaningful comparison because they pursued these contrasting approaches among the same population and against the same enemy at the same time and place. The study compares each unit’s approach and finds that neither approach was successful absent the other. The article concludes by recommending further research into combining the approaches at the operational level.