共查询到15条相似文献,搜索用时 109 毫秒
1.
2.
3.
4.
针对现有方法一般是基于时间或距离的定值来确定碰撞区域的问题,提出了一种基于入侵机和无人机(UAV)运动信息的无人机动态碰撞区建模方法.首先,根据无人机与入侵机的运动状态、两机之间的最小安全距离等信息,通过几何方法得出无人机不采取任何规避机动时两机将发生碰撞区域的解析表达式,即无机动碰撞区数学模型;其次,考虑无人机的机动能力约束,计算了无人机采取最大过载转弯机动(左转或右转)时两机恰好避免碰撞发生的边界,即最大机动碰撞区数学模型;在此基础上,提出了不可规避区的概念;进而定义了安全飞行包络,它是无人机能够规避入侵机威胁的分界线;最后通过理论和仿真结合分析了影响各区域的主要因素.仿真与分析结果表明所建碰撞区不仅可以帮助无人机选择规避机动方式,而且能够帮助无人机判定常规避撞机动是否失败,并使无人机及时采取最大过载转弯机动,对无人机安全避撞决策具有实际参考价值. 相似文献
5.
6.
地球静止轨道成像式遥感卫星的光学成像相机在轨工作期间需要避免阳光的照射,针对现有滚动轴姿态机动算法存在规避开始时初始角速度过大的问题,提出一种改进的滚动轴机动太阳规避算法。该算法在规避开始与结束时,设计一定的规避角度余量,将建立机动初始状态的过程由达到规避角度的瞬间延伸到角度余量区间中,延长建立初始状态的时间,减小初始角速度。系统数学仿真和测试验证证明该算法简单可靠,在开始规避时,初始角速度由0.2(°)/s减小到0.014(°)/s,整个规避过程平稳,具有良好的工程应用价值。 相似文献
7.
空间碎片的碰撞预警与规避能有效避免碰撞事件的发生.碰撞概率是碰撞预警的主要判据,也是航天器规避机动决策的主要依据.由于计算碰撞概率的各相关参数带有误差,导致计算得到的碰撞概率值并不准确,难以做出规避机动决策,因此评估碰撞概率值的可信程度是亟需解决的问题.本文给出了一种碰撞概率置信度的计算方法,利用各影响参数的标准差,通过误差传递的方法计算碰撞概率的标准差,结合单边Chebyshev不等式,给出碰撞概率值大于10-4阈值时的置信度,并结合实际案例进行了分析. 相似文献
8.
及时准确地发现在轨卫星的轨道异常意义重大. 通过有效的异常算法, 能够找出发生轨道异常的碎片或航天器, 为空间碎片碰撞预警系统分析和验证碰撞事件提供数据支持. 通过对利用TLE (Two Line Elements)数据分析LEO在轨卫星轨道异常的方法研究, 提出了一个利用单个卫星相邻根数时间差控制加综合判据的判别方法. 分析表明, 相对于取单一因素阈值的判别方法, 综合判据法能够最大限度地减少漏判, 并且保持相对较高的判断准确率. 相似文献
9.
空间在轨物体的轨道异常是航天工程及预警领域普遍关注的问题,及时发现轨道异常意义重大,通过分析空间物体的轨道异常,可以及时发现和识别规避事件或碰撞事件,还可以了解监测网的能力.本文提出一种基于TLE数据的简单的轨道异常分析方法——长半轴变化法.该方法快速有效,应用到低轨在用卫星和美俄解体碎片的异常分析中,异常物体正确识别率可达到100%;对美俄解体碎片进行轨道异常分析后得出,美国空间监视网可以稳定探测90%以上的解体碎片. 相似文献
10.
11.
12.
《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2020,65(1):419-434
In the framework of space debris, the orbit determination process is a fundamental step, both, for researchers and for satellite operators. The accurate knowledge of the orbit of space debris objects is needed to allow space debris characterization studies and to avoid unnecessary collision avoidance maneuvers.The accuracy of the results of an orbit determination process depends on several factors as the number, the accuracy, the kind of processed measurements, their distribution along the orbit, and the object-observer relative geometry. When the observation coverage of the target orbit is not homogeneous, the accuracy of the orbit determination can be improved processing different kind of observables. Recent studies showed that the satellite laser ranging technique can be successfully applied to space debris.In this paper, we will investigate the benefits of using laser ranges and angular measurements for the orbit determination process. We will analyze the influence of the number of used observations, of the covered arc of orbit, of each observable, and of the observation geometry on the estimated parameters. Finally, using data acquired on short observation arcs, we analyze the achievable accuracies for the orbital regimes with the highest space debris density, and to the consequences of the data fusion on catalog maintenance operations. The results shown are obtained using only real data (both angular and laser measurements) provided by sensors of the Swiss Optical Ground Station and Geodynamics Observatory Zimmerwald owned by the Astronomical Institute of the University of Bern (AIUB) and for some studies also using ranges provided from other stations of the International Laser Ranging Service (ILRS). 相似文献
13.
During recent years, A de-orbit disposal of SinoSat 2 satellite and the depletion of the residual propellant after SC/LV separation for all LM-4 series launch vehicles were carried out. Stuffed Whipple Shields based on hypervelocity impact particles were developed. Routine observation and collision avoidance were performed. The main progress in space debris research will be introduced from three aspects: mitigation, spacecraft protection, observation and collision avoidance. 相似文献
14.
快速准确地分析空间碎片群轨道演化行为对于其他在轨航天器碰撞规避至关重要。在各摄动力的作用下,空间碎片群演化运动呈现出复杂的非线性特征。空间碎片群体个体数量巨大,如果通过对空间碎片群中每个空间碎片进行轨道积分来分析群体预报的方法会导致计算量过大。针对该问题,提出一种基于多项式近似的轨道快速预报分析方法。该方法将空间碎片群分为少量的标称碎片和其他大量关联碎片。针对标称碎片的轨道预报采用数值积分求解保证预报精度;而针对其他大量的关联碎片轨道预报问题,采用多项式泰勒展开半解析方法求解,从而在保证预报精度的前提下有效减少空间碎片群轨道预报的计算量。为了验证方法的有效性,对不同空间碎片群进行了轨道预报仿真。仿真结果表明,当轨道预报精度设定在1m范围内时,多项式近似算法的计算量较蒙特卡洛方法计算效率提高了2.2~17.2倍,验证了所提出方法的有效性。 相似文献
15.
Improved orbit predictions using two-line elements 总被引:1,自引:0,他引:1
Creon Levit William Marshall 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2011
The density of orbital space debris constitutes an increasing environmental challenge. There are two ways to alleviate the problem: debris mitigation and debris removal. This paper addresses collision avoidance, a key aspect of debris mitigation. We describe a method that contributes to achieving a requisite increase in orbit prediction accuracy for objects in the publicly available two-line element (TLE) catalog. Batch least-squares differential correction is applied to the TLEs. Using a high-precision numerical propagator, we fit an orbit to state vectors derived from successive TLEs. We then propagate the fitted orbit further forward in time. These predictions are validated against precision ephemeris data derived from the international laser ranging service (ILRS) for several satellites, including objects in the congested sun-synchronous orbital region. The method leads to a predicted range error that increases at a typical rate of 100 m per day, approximately a 10-fold improvement over individual TLE’s propagated with their associated analytic propagator (SGP4). Corresponding improvements for debris trajectories could potentially provide conjunction analysis sufficiently accurate for an operationally viable collision avoidance system based on TLEs only. 相似文献