某型运载火箭地震响应分析及减震设计

竖立状态的运载火箭一旦遭遇地震,极易造成箭体倾倒等灾难性后果。为了确保运载火箭在地震中的安全,针对某型运载火箭,采用时程分析法对其进行地震响应分析,得到了火箭的弯矩、位移响应峰值沿箭体纵向的分布规律。分析了火箭关键位置处弯矩响应的频域特性,设计了火箭的减震措施,并分析了火箭与发射台的连接刚度、隔震支座刚度对火箭地震响应的影响规律。结果表明:火箭弯矩响应的最大值发生在靠近火箭尾段的位置,位移响应的最大值发生在火箭头部位置;改变火箭与发射台连接刚度以及在发射台底部加装隔震支座的方式可以有效地减小火箭的地震响应。     

The political economy of drones

This paper provides a political economy analysis of the evolution of unmanned aerial vehicles (UAV), or ‘drones’ in the USA. Focus is placed on the interplay between the polity and private economic influences, and their impact on the trajectory of political, economic, and military outcomes. We identify the initial formation of the drone industry, trace how the initial relationships between the military and the private sector expanded over time, and discuss present relationships. Understanding the historical evolution of UAV technology, as well as the major players in the industry today, is important for ongoing policy debates regarding the use of drones both domestically and internationally.     

INCOMPLETE ROHLFS–SULLIVAN ANALYSIS OF THE COST-EFFECTIVENESS OF ARMORED TACTICAL WHEELED VEHICLES FOR OVERSEAS US ARMY OPERATIONS

This comment addresses the Rohlfs–Sullivan analysis titled: ‘The Cost-Effectiveness of Armored Tactical Wheeled Vehicles [TWVs] for Overseas US Army Operations.’ The analysis evaluated policies to replace Type 1 and 2 TWVs with Type 3s. There is no evidence the analysis factored in fatality causes, fatality relationships to vehicles, or compared survivability of vehicles. Furthermore, it did not note when Type 3 TWVs were requested, when they impacted fatalities, or TWV use policies. It also assumed Type 3 TWVs prompted negative unit behaviors while discounting evidence of positive behaviors. In summary, the analysis is incomplete and should be revised.     

履带车辆下长坡液力辅助制动控制策略仿真研究

针对履带车辆下长坡制动过程中不同制动力的分配关系,在液力减速器和整车下坡动力学分析的基础上,研究了基于液力辅助制动的履带车辆下长坡制动控制策略,建立了基于SIMULINK的履带车辆整车动态仿真模型,对液力减速器的持续制动性能和控制策略的有效性进行了仿真．结果表明,车辆下坡持续制动时,适时应用液力减速器,能够有效分流整车制动功率,明显降低机械制动器的工作负荷,满足整车安全恒速下坡的要求．     

基于灰色关联投影法的空中加油机驻场选址评价

提出了一种基于灰色关联投影法的空中加油机驻场选址评价方法,分析了空中加油机驻场选址影响因素,设计了评价指标体系,并运用熵值理论客观赋权,构建了加权灰色关联决策矩阵。通过比较备选方案与理想方案灰色关联投影角,根据灰色关联投影值对备选方案进行优劣排序。算例分析结果符合现实场站选择条件,说明该方法能够有效解决空中加油机驻场选址问题。     

姿态角单次调整的固体运载火箭耗尽关机能量管理方法

固体运载火箭传统耗尽关机制导方法姿态角调整次数过多,不利于控制系统设计。提出了姿态角单次调整的耗尽关机能量管理策略:以火箭的待增视速度方向为基准,通过计算火箭所需耗费的视速度,优化选取火箭的初、末姿态角;火箭以恒定角速率从初姿态角变为末姿态角,达到末姿态角时保持恒定,直至耗尽关机。仿真结果表明,新方法在满足火箭的终端速度约束条件下,视速度模量耗费百分比超过30%,且姿态角单向调整,有利于控制系统的工程设计。     

The view from above: how the Royal Air Force provided a strategic vision for operational intelligence during the Malayan Emergency

It has long been held that the Federation of Malaya’s counter-insurgency campaign during the First Malayan Emergency (1948–60) was determined by the use of intelligence. Special Branch — the Federation’s primary intelligence agency — dominates the prevailing paradigm of how the insurgent threat was tackled. Conversely, the role of the Royal Air Force (RAF) within this paradigm is very limited. Most observers simply dismiss the role of photoreconnaissance or airstrikes as being largely inconsequential to the counter-insurgency effort. This is perhaps understandable: the Emergency was after all a ‘policing action’ and the insurgents were largely hidden under Malaya’s jungle canopy and amongst the Chinese community. However, further scrutiny reveals that the RAF made a much more significant contribution to the intelligence element of the counter-insurgency campaign than previously realised. First, the RAF decided to locate their Advanced Headquarters with the Army’s General Headquarters. This led to the creation of the Land/Air Operations Room, through which intelligence, tasking and resources were coordinated. Moreover, the RAF put its intelligence teams into the field to provide a practical link between local units and theatre-level assets. Second, with the support of the Army, the RAF established at the beginning of the Emergency the Joint Air Photographic Intelligence Board (Far East). This coordinated all photographic intelligence requirements throughout the Emergency, which was then delivered via the Joint Air Photographic Centre (Far East). Hence, via Joint Operations Centre and JAPIB (FE), the RAF provided both the practical means for effective joint intelligence operations at theatre level throughout the Emergency.     

运载火箭摄动制导导引系数实时计算方法

对于新型运载火箭,没有相近型号导引系数数据供参考,采用传统试探法计算量大,在制导方案初期论证中不能满足多方案快速计算的需求。在引入理想弹道剩余飞行速度概念的基础上,提出导引系数实时计算方法。本方法对当前实时状态参数和后续飞行段弹道进行了综合考虑,通过数字仿真表明导引精度高于传统常系数导引方法。由于本方法对导引能力进行了预估,因而制导指令不会剧烈变化,易于姿态控制系统的设计实现。同时,由于采用完全解析法,对箭载计算机计算能力要求几乎没有增加,易于工程实现。     

基于车辆稳态动力学特性的汽车动态轨迹规划

针对高动态环境下驾驶辅助系统（ADAS）的轨迹规划问题,提出基于车辆稳态动力学特性的动态轨迹规划算法。该算法首先在交通车轨迹预估基础上建立搜索空间,接着利用车辆稳态动力学模型作为轨迹发生器,在搜索空间中对轨迹发生器产生的轨迹进行评价,最后根据驾驶意图和优化条件选择最优轨迹。文章采用基于最优加速度预瞄理论的轨迹跟踪算法,建立了七自由度车辆动力学模型,并在Simulink环境下搭建仿真平台,进行超车仿真实验。实验结果表明,本文提出的算法可行、有效。     

有人机/无人机协同空地攻击效能评估的综合指数模型

研究了未来有人机/无人机协同空地攻击的典型作战模式,然后根据混合编队的作战过程和特点,提出了一种建立有人机/无人机协同空地攻击效能评估的综合指数模型;同时确定了综合指数模型中各分系统和分项能力的评估模型。最后以6种有人机和6种无人机的协同空地攻击效能评估为例计算并检验了模型的可用性。