共查询到20条相似文献,搜索用时 62 毫秒
1.
PHD filters of higher order in target number 总被引:14,自引:0,他引:14
The multitarget recursive Bayes nonlinear filter is the theoretically optimal approach to multisensor-multitarget detection, tracking, and identification. For applications in which this filter is appropriate, it is likely to be tractable for only a small number of targets. In earlier papers we derived closed-form equations for an approximation of this filter based on propagation of a first-order multitarget moment called the probability hypothesis density (PHD). In a recent paper, Erdinc, Willett, and Bar-Shalom argued for the need for a PHD-type filter which remains first-order in the states of individual targets, but which is higher-order in target number. In this paper we show that this is indeed possible. We derive a closed-form cardinalized PHD (CPHD) filter, which propagates not only the PHD but also the entire probability distribution on target number. 相似文献
2.
3.
4.
基于打靶法的战机攻击导引方法研究 总被引:1,自引:0,他引:1
在以往战机空战攻击导引研究中, 仅考虑如何导引载机使之与目标的相对距离达到武器发射射程, 没有同时考虑拦截角度的需求; 或只考虑拦截角而不考虑相对距离的需求。针对这一不足, 本文在深入分析战机攻击导引理论问题的基础上, 创新地用打靶法, 同时考虑追击距离与拦截角度两末端约束, 进行攻击轨迹优化设计。大量仿真研究表明, 所设计的攻击导引方法, 不仅能很好地满足所需的相对距离和拦截角两末端约束, 而且具有较好的可实现性。本研究可为新一代战机导引攻击系统的研制与某型飞机的国产化设计提供参考。 相似文献
5.
6.
为了提高星敏感器的数据更新率,必须减少星像坐标的提取时间。在提取星像坐标的过程中,现有基于FPGA的方法虽然避免了星图保存和读取过程,然而需要高性能的FPGA才能实现。为此提出了一种采用行列聚类并行的星像坐标提取方法,将逐个像素聚类的方式优化成像素队列聚类的方式,实现了对恒星星像坐标的实时提取,可以解决现有的实时提取星像坐标方法中像素输出时钟与处理时钟不匹配的问题,达到1个时钟周期处理完1个像素的目的,从而减少了星像坐标的提取时间,提高了星敏感器的实时性。最后把该方法嵌入到某星敏感器系统中,实验结果表明,与现有基于FPGA的实时提取星像坐标方法相比,在相同工作频率且不降低星像坐标提取精度的前提下,提取时间仅为现有方法的21.1%,数据更新率提高了近5倍。因此,该方法不但具有实时性,而且具有较好的鲁棒性。 相似文献
7.
The dynamic response of the rotor depends on not only itself but also the dynamical characteristics of the structures that support it. In this paper, the coupling vibration characteristics of the rotor and supporting structure are studied using one simple rotor-supports model firstly, and then the dynamic stiffness of the typical supporting structure of an aero-engine is investigated in use of both numerical and experimental methods. While, one simulation strategy is developed to include dynamic... 相似文献
8.
Hyoung Joong Kim Gyu-in Jee Jang Gyu Lee 《IEEE transactions on aerospace and electronic systems》1996,32(2):607-612
A tree network consisting of communicating processors is considered. The objective is to minimize the processing time by distributing the processing load to other nodes. The effect of the order of load distribution on the processing time is addressed. An algorithm which optimally determines the order of load distribution is developed. It is shown that the order depends only on the channel capacity between nodes but not on the computing capability of each node 相似文献
9.
Shukla U.S. Mahapatra P.R. 《IEEE transactions on aerospace and electronic systems》1988,24(3):231-238
Proportional navigation (PN) equations are not solvable in closed form. Linearized solutions have been widely used for PN system analysis and design, but these are based on overly restrictive assumptions regarding the initial geometry, and are valid only for near-tail-chase pursuits. A generalization of the linearized approach is presented which yields more-accurate estimates of pursuer lateral acceleration than the classical linear solutions as verified by comparison with `exact' numerical solutions. Further, the solution is applicable over a much wider range of engagement geometries. The treatment is based on a closed-form quasilinearized solution of the PN equations followed by the small-angle approximation only to line-of-sight (LOS) angle rate 相似文献
10.
11.
有限元复线性方程组的系数矩阵一般具有稀疏性和对称性的特点,全稀疏存贮方法就是利用这些特点,只存贮对称部分的非零元素,采用链表式管理,即节省存贮空间,又便于动态更改.在一般双共轭梯度法的基础上,本文利用广义变分原理对内积进行了重新定义,使双共轭梯度法求解复线性方程组更为有效.数值算例表明这种双共轭梯度法结合全稀疏存贮方案的求解算法在时间和存贮上都较为占优,可靠高效,能够应用于有限元线性方程组的求解. 相似文献
12.
C. Fröhlich 《Space Science Reviews》2006,125(1-4):53-65
Since November 1978 a set of total solar irradiance (TSI) measurements from space is available, yielding a time series of
more than 25 years. Presently, there are three TSI composites available, called PMOD, ACRIM and IRMB, which are all constructed
from the same original data, but use different procedures to correct for sensitivity changes. The PMOD composite is the only
one which also corrects the early HF data for degradation. The results from the detailed analysis of the VIRGO radiometry
allow a good understanding of the effects influencing the long-term behaviour of classical radiometers in space. Thus, a re-analysis
of the behaviour of HF/NIMBUS-7 and ACRIM-I/SMM was indicated. For the former the situation is complicated by the fact that
there are no in-flight means to determine changes due to exposure to solar radiation by comparison with a less exposed radiometer
on the same spacecraft. The geometry and optical property of the cavity of HF is, however, very similar to the PMO6-type radiometers,
so the behaviour of the PMO6V radiometers on VIRGO can be used as a model. ACRIM-I had to be revised mainly due to a henceforth
undetected early increase and a more detailed analysis of its degradation. The results are not only important for solar radiometry
from space, but they also provide a more reliable TSI during cycle 21. The differences between the revised PMOD composite
and the ACRIM and IRMB are discussed by comparison with a TSI reconstruction from Kitt-Peak magnetograms. As the PMOD composite
is the only one which has reliable data for cycle 21, the behaviour of the three solar cycles can now be compared and the
similarities and differences discussed. 相似文献
13.
Signal-in-space modeling of approach and landing guidance systems such as the microwave landing system (MLS), which is necessary for aircraft certification, is addressed. A technique which can, in principle, identify the error sources in navigation systems and can also perform the inverse operation of synthesizing an error generator whose output is statistically equivalent to the original error data is described. The technique can also be used to validate equipment error budget assumptions. The identification and synthesis technique applies not only to MLS but to all navigation systems 相似文献
14.
15.
先拉伞绳法数学模型及拉直力预测 总被引:1,自引:0,他引:1
给出了考虑伞绳粘弹性的降落伞先拉伞绳法拉直过程预测方法.建立了拉直过程数学模型的基本方程,理论分析了基本方程中粘性项对张力波在伞绳中传播的作用;弹性张力波不仅使伞衣套一端产生的张力通过伞绳传到前置体一端在时间上滞后一些,而且由于拉直过程中存在着吸收和弥散现象,使两端的张力不能相等.使用该模型计算了伞拉直运动和拉直力,对拉直力动态变化过程进行了分析.计算表明:前置体一端承受的最大拉直力不仅与伞衣底边被拉动瞬间产生的最大张力有关,而且与拉出伞衣底边以后产生的载荷张力有关. 相似文献
16.
大型运输机机翼弯曲载荷计算 总被引:1,自引:0,他引:1
简要叙述了飞机平飞时影响机翼弯曲载荷的主要因素;重点介绍了机翼升力、机翼油箱燃油重力、机翼结构重力沿翼展分布数学模型的建立和机翼弯曲载荷计算公式的推导过程;所述方法虽然是针对大型运输机提出的,但对其它类型飞机同样适用。 相似文献
17.
18.
飞机机翼上的主要接头传递着机翼上的绝大部分载荷,且其应力分布较为复杂.本文采用子模型法建立了某型机机翼复杂接头部位的有限元精细模型,计算出该接头部位的细致应力分布,并以此为基础对接头处肋缘条截面构型进行优化,得到的结果为呈阶梯状的肋缘条截面构型.该构型不仅满足提高接头耐久性的设计目的,也由于重量的减轻改善了接头的经济性. 相似文献
19.