地球静止轨道粗定位的北斗系统接收机快速定位方法

传统全球导航卫星系统信号发射时间的整毫秒恢复算法,在接收机概略位置未知时存在计算量剧增而无法应用的问题。利用北斗系统混合星座中GEO卫星电文速率高的这一特点,提出一种基于GEO粗定位的北斗接收机快速定位的方法。在接收机概略位置完全未知的情况下,使用已获取完整信号发射时刻的纯GEO星座进行粗定位,根据解算获得的概略位置对非GEO卫星发射时刻毫秒整数时间进行恢复,利用所有可见卫星进行精确定位。使用国际全球连续监测评估系统测站观测伪距对算法进行验证,国内测站可100%实现伪距恢复,完成快速定位。仿真遍历中国区域用户,在仿真伪距增加均值为0,标准差为6m噪声,截止仰角为0°时,中国附近区域实现快速定位概率均大于98.68%,其中约80%的中国附近区域可以100%实现卫星信号传输时间恢复并完成快速定位。     

采用时序多属性评价方法的空战威胁排序

鉴于空战中威胁目标的多属性及动态变化特点,提出采用时序多属性评价方法来解决空战目标动态威胁排序问题。在建立空战威胁指标体系基础上,采用熵权法确定目标属性权重,并通过指数分布法确定各时刻权重,最后综合依据威胁目标多时刻的属性信息,实现了空战动态威胁排序。仿真结果说明该方法的合理性。     

基于时间切片的通信计划合规性评估模型

针对体系作战背景下通信计划规划任务多线性和关系复杂的问题,提出了一种通信计划合规性评估模型。该模型通过构建计划时间切片,描述了多个通信保障任务主线在各阶段的全局关系视图,并定义了通信链路连接矩阵、电磁频谱三级规划和指控系统命名类量化,描述了通信计划的基本内容,同时定义了3类评估规则和3种评估运算法则,形成了完整的合规性评估体系。最后,通过实例分析验证了模型有效性,结果表明,评估模型能够较好地区分不同信息需求下的通信计划合理程度。     

基于锥形量热法的油池火相似性及点火特性模拟实验

针对油料池火灾相似性及点火特性研究需要,构建了一种基于耗氧原理的油池火锥形量热法模拟实验系统,引入火灾尺度相似性概念,研究了实验室尺度油池火与真实尺度油池火的相似性关系,探讨了实验室尺度油池火预测真实尺度油池火的可行性,基于实验室尺度锥形量热法研究了油池火点火特性,得到了辐射强度、辐射距离对油料点燃时间的影响规律以及点燃时间与锥照射强度之间的拟合公式。     

基于自适应二阶终端滑模的航天器有限时间姿态机动算法

针对航天器有限时间姿态机动问题,提出一种自适应二阶终端滑模控制算法。设计一种终端滑模面,保证系统状态能够在有限时间内沿滑模面收敛到系统原点;为克服系统抖振,设计了二阶终端滑模控制器,并采用参数自适应估计项补偿系统中的外部干扰力矩。基于Lyapunov函数法证明了二阶自适应终端滑模控制器能够保证闭环系统实际有限时间稳定。仿真结果表明,提出的姿态机动算法响应速度快、精度高,能够有效实现对系统抖振和外部干扰的抑制,具有重要的科学意义和工程应用价值。     

金属射流欧姆加热效应的影响因素分析

为探究影响金属射流欧姆加热效应的因素,在被动电磁装甲系统等效电路模型的基础上,根据虚拟源点理论建立金属射流的作用时间模型,进一步明确金属射流在侵彻被动电磁装甲过程中每部分射流微元的作用时间;结合金属射流的比作用量模型,利用Matlab软件对金属射流的电流和比作用量波形随被动电磁装甲系统的电感、电容、电阻和充电电压的变化规律进行数值分析．仿真结果表明：随着系统电感的减小、电阻的减小、电容的增大和充电电压的增大,金属射流比作用量的峰值增大,有利于射流发生电爆炸．     

基于占有率的信号相位交通状态实时判别模型

在国内交通检测手段的现实背景下,各种道路交通状态判别模型的可靠性和实用性一直不足。因此基于车道战略检测器和战术检测器的时间占有率提出了一种新的实用的相位交通状态判别模型,其中包括检测器的布设,占有率阈值的确定,相位交通状态的判别方法。通过VISSIM4.2仿真实验证明,该模型可以准确地判定符合人们主观判断的相位交通状态,并且可以很好地应用目前普遍采用的检测手段,实用性强。     

Two novel critical shock models based on Markov renewal processes

In this paper, we investigate systems subject to random shocks that are classified into critical and noncritical categories, and develop two novel critical shock models. Classical extreme shock models and run shock models are special cases of our developed models. The system fails when the total number of critical shocks reaches a predetermined threshold, or when the system stays in an environment that induces critical shocks for a preset threshold time, corresponding to failure mechanisms of the developed two critical shock models respectively. Markov renewal processes are employed to capture the magnitude and interarrival time dependency of environment-induced shocks. Explicit formulas for systems under the two critical shock models are derived, including the reliability function, the mean time to failure and so on. Furthermore, the two critical shock models are extended to the random threshold case and the integrated case where formulas of the reliability indexes of the systems are provided. Finally, a case study of a lithium-ion battery system is conducted to illustrate the proposed models and the obtained results.     

Three-dimensional coordinates test method with uncertain projectile proximity explosion position based on dynamic seven photoelectric detection screen

To objectively obtain the three-dimensional coordinates of the projectile fuze proximity explosion when projectile intersects the head of missile target, we propose a dynamic seven photoelectric detection screen test method, which is made up of six plane detection screens and a flash photoelectric dynamic detection screen. The three-dimensional coordinates calculation model of the projectile proximity explosion position based on seven plane detection screens with dynamic characteristics is established. According to the relation of the dynamic seven photoelectric detection screen planes and the time values, the analytical function of the projectile proximity explosion position parameters under non-linear motion is derived. The projectile signal filtering method based on discrete wavelet transform is explored in this work. Additionally, the projectile signal recognition algorithm using an improved particle swarm is proposed. Based on the characteristics of the time duration and the signal peak error for the projectile passing through the detection screen, the signals attribution of the same projectile passing through six detection screens are analyzed for obtaining precise time values of the same projectile passing through the detection screens. On the basis of the projectile fuze proximity explosion test, the linear motion model and the proposed non-linear motion model are used to calculate and compare the same group of projectiles proximity explosion position parameters. The comparison of test results verifies that the proposed test method and calculation model in this work accurately obtain the actual projectile proximity explosion position parameters.     

实弹射击弹着点定位算法研究

弹着点定位是实弹射击中实现自动报靶的关键。利用弹头撞击钢质靶板产生的振动波到达四个顶点上的振动传感器的时间差,来实现弹着点的定位。弹着点的位置定位算法,利用两次加权的方法,消除噪声等因素产生的误差,最后经过实验测试,分别对一次、二次加权的结果进行仿真以及数据的拟合。结果证明,该算法对弹着点的位置估计随着加权次数的增加,也会更加接近实际值。