无缝GPS／INS组合导航系统的设计与实现

针对GPS卫星信号失锁条件下GPS/INS组合导航性能大幅度下降的缺点,设计了一种基于ANFIS的无缝组合导航方法,当卫星数目不低于4颗时采用伪距,伪距率的卡尔曼滤波算法,一旦卫星数目少于4颗时采用ANFIS系统估计导航误差,抑制INS的误差积累,从而实现无缝导航.动态车载实验表明,该方法切实可行,相对于传统的紧组合方法,有效地提高了组合导航系统的定位精度和抗干扰能力.     

基于联邦卡尔曼滤波的组合导航定位算法

在传统的GPS/INS紧耦合组合导航系统中,由于伪距和多普勒频移误差的存在,系统存在一定的误差偏移。针对这种误差偏移,设计了一种联邦卡尔曼滤波组合导航算法,该算法采用二级卡尔曼滤波器,将卫星接收模块解算出的伪距信息和多普勒频移信息在第一级卡尔曼滤波后,与INS模块结算出的信息进行修正处理,再通过主滤波器得到紧耦合算法的INS解算结果校正量和定位位置最优估计。通过计算机仿真结果分析表明,该方法相对于传统的紧耦合组合导航算法可以有效减小误差,具有一定的理论价值和实用价值。     

INS/GPS/CNS组合导航系统仿真

在分析INS、GPS、CNS导航系统特点的基础上,建立了组合导航系统的误差模型,提出了一种基于联邦滤波器的INS/GPS/CNS的组合导航算法,采用平台失准角、INS与GPS的位置之差和速度之差作为观测量,对算法进行了仿真研究。仿真结果表明:通过校正惯导平台、消除导航参数误差,可以大大提高系统的导航精度。     

基于Simulink的组合导航信息融合仿真平台的构建

目前进行组合导航方面各种算法的研究主要还是利用仿真进行验证,而对这一方面进行仿真的基础性平台却未曾真正建立.基于Simulink用于仿真的独特优势,利用Simulink工具,采用信息融合中普遍采用的联合滤波结构构造了INS/GPS/GLONASS/双星导航融合仿真平台,详细论述了平台的构建过程以及基于这一平台进行仿真研究存在的优势,并通过卡尔曼滤波算法进行了组合导航系统的仿真实现,绘出了仿真结果误差图形.仿真结果证明系统模型正确、平台设计合理,可以作为进行组合导航系统研究的仿真平台.     

高动态环境下基于H_∞滤波的深组合导航技术

捷联惯性导航系统(SINS)/全球定位系统(GPS)组合导航系统是适用飞机和现代武器装备的高精度导航系统。针对高动态环境下GPS/SINS组合导航系统的定位精度问题,以炮射无人机为例提出基于H∞滤波技术的SINS/GPS伪距、伪距率深组合导航方案,用于提高高动态环境下组合导航系统的精度和鲁棒性。仿真结果表明,H∞滤波器不但比Kalman滤波器鲁棒性强,而且可用于带有强有色噪声的高动态系统中,并能保持较高的精度。     

自行武器GPS/INS组合导航系统的设计

介绍了某自行武器的 GPS/ INS组合导航系统的设计方案 ,内容包括该系统的数学模型、信息融合和系统仿真。实验结果表明 ,该设计改善了系统性能 ,提高了导航定位的精度、可靠性和实用性     

基于多传感器信息融合技术的联合卡尔曼滤波器的设计及应用

介绍了基于多传感器信息融合技术的联合卡尔曼滤波器的一般设计方法,并将此方法运用于舰船INS/GPS/Loran-c组合导航系统中.理论分析与仿真结果表明,该联合卡尔曼滤波器的设计合理,算法具有全局最优性,能够提高系统的导航精度和容错能力.     

UKF与EKF在GPS/INS超紧组合导航中的应用比较

针对GPS/INS超紧组合特点,基于四元素法建立了系统的非线性状态方程,利用GPS接收机原始伪距测量信息对系统状态进行观测,并将EKF和UKF方法运用到系统进行比较,仿真结果表明UKF在姿态、位置估计上精度要优于EKF。     

自主式车载组合导航系统研究与仿真

考虑到车载组合导航系统运行时间长、地形环境复杂的特点,将零速修正技术与惯导/里程计/气压高度表组合导航系统相结合使用,采用序贯处理和平方根滤波算法,建立了实用的卡尔曼滤波模型。相比基本卡尔曼滤波算法,该方法实现简单,计算量小,抑制了滤波的发散,提高了滤波的精度。最后对组合导航系统进行仿真验证,取得了较为满意的结果。与INS/GPS组合导航系统相比,该系统具有良好的自主性及适应性。     

GPS/INS组合导航技术研究

随着GPS和INS技术的发展,组合导航系也逐渐成熟。采用卡尔曼滤波对GPS/INS组合导航系统进行仿真,并将仿真结果和INS仿真结果相比较得出,GPS/INS组合导航系统经过滤波的误差估计精度得到了显著提高,并比INS单一导航有明显优势。     

Putin – the masked nemesis of the strategy of ambiguity

Recent events demonstrate the complex and adaptive approach employed by Russia to reassert influence in Europe. The changing face of Russia’s strategy commenced in 2007 when it launched a crippling cyber-attack against Estonia. This was followed by a large Russian conventional attack against Georgia in 2008, occupying two large areas of the nation. 2014 witnessed the Russian annexation of Crimea where in just a week, Russia seized control of Crimea “without firing a shot.” The annexation of Crimea was rapidly followed by a Russian inspired and led subversive war in eastern Ukraine. The common thread among these diverse Russian operations is its use of ambiguity to confound and confuse decision makers in the West.     

India's counter-insurgency experience: the ‘trust and nurture’ strategy

The Indian Army, a force trained primarily for conventional warfare, has been engaged in internal counter-insurgency operations since the 1950s. Despite such a long innings on a counter-insurgency mode, little attention has been accorded within military circles to doctrinal innovation for waging sub-conventional warfare in India's democratic political context. At best, the Army continues to view counter-insurgency duty as secondary to its primary duty of defending India from external conventional threats. By conceptualizing a counter-insurgency strategy of ‘trust and nurture’, this article aims to fill this critical doctrinal gap in India's military policy. The author argues that a counter-insurgency strategy of ‘trust and nurture’ based on democratic political culture, measured military methods, special counter-insurgency forces, local social and cultural awareness and an integrative nation-building approach will result in positive handling of India's internal security problems. The author utilizes India's counter-insurgency experiences in Assam, Mizoram, Nagaland, Punjab, and Operation ‘Sadhbhavana’ in Jammu and Kashmir as illustrative empirical indicants in order to validate the ‘trust and nurture’ strategy.     

An Unlikely Alliance: Portuguese and South African Airpower in Angola, 1968–1974

The war that Portugal was obliged to fight in Africa began in 1961 and immediately stretched the resources of its armed forces. Nowhere was this thinness more apparent than in policing the vast territory of Angola. The east and southeast of Angola were particularly vulnerable, as the area was a vast, sparsely populated region characterised by enormous featureless plains or chanas covered in tall grass and broken by an extensive river system and mountainous forests. The only military solution to policing these immense spaces was aviation and specifically the helicopter that could carry troops into battle, protect them with a gunship and bring them home when the operation was concluded. The immediate problem for the Portuguese Air Force (Força Aérea Portuguesa or FAP) in Angola and elsewhere was a scarcity of helicopters. The solution was an alliance with South Africa, which had a strong inventory of Alouette IIIs, to help in policing the east. This move was likewise in the interest of South Africa, as its threat came from Zambia through south-eastern Angola. This article examines the strategic and tactical development of this unusual, cross-cultural alliance and the symbiotic relationship that resulted in destruction of the enemies of both in Angola.     

国内外结构钢焊条研究的现状与发展

本文主要介绍了国外焊条的现状和发展趋势,包括焊条的高韧性、高效率、低尘低毒和耐吸潮性能,为国内的焊条研究提供了参考依据。     

A Sign of Victory?: ‘Scottish Swords’ and Other Weapons in the Possession of the ‘Auld Innemie’

Many late medieval documents, notably inventories of arms and armour, of Englishmen contain references to ‘Scottish swords’ and other weapons. What did the compilers of these documents mean when they described a weapon as ‘Scottish’? How did such weapons come to be in the possession of these men? This article will attempt to explain this phenomenon drawing on primary documentary sources and surviving material culture from Glasgow Museums’ collections and others, as well as artworks from the period.     

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).     

Cyberpower in Strategic Affairs: Neither Unthinkable nor Blessed

Abstract

This article explores the effect of connectivity on strategic affairs. It argues that the effect on war's character is potentially, although not yet shown in practice, considerably large. Its effect upon the distribution of power among states in the international system is small, contrary to the claims of ‘cyberwar’ alarmists. All told, however, its effect upon strategic affairs is complex. On the one hand, it represents a significant advance in the ‘complexification’ of state strategies, understood in the sense of the production of intended effects. On the other hand, strategists today – still predominantly concerned with the conflicts and confrontations of states and organised military power – are generally missing the power which non-traditional strategic actors, better adapted to the network flows of the information age, are beginning to deploy. These new forms of organization and coercion will challenge the status quo.