共查询到19条相似文献，搜索用时 109 毫秒
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本文利用误差改正模型方法,得到精密单点定位总模型,利用这个模型对多个历元数据进行解算,并与非改正结果进行了比较、分析。分析结果表明模型能够显著提高单点定位的精度。 相似文献
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为了提高精密单点定位精度,本人通过编程实现了电离层改正的双频伪距改正法和Klobuchar模型。分别将这两种算法加入到伪距单点定位程序中,通过定位结果分析发现Klobuchar模型优于双频伪距改正法的改正效果。 相似文献
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本文探讨了利用IGS精密星历的双P码伪距精密单点定位的基本原理、处理方法、所涉及的误差改正及数据处理中的一些关键技术。最后利用自己编写的精密非差单点定位软件计算和分析了实测数据。计算结果表明,单历元残差均小于1.8米。各历元解算的测站坐标与平均值之间的坐标差值为:在X方向上均小于1m,在Y、Z方向上均小于5m米。 相似文献
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利用IGS提供的高精度对流层天顶延迟数据,在全球范围内对四种常用天顶对流层延迟模型的精度,进行了科学、合理的评估。得出EGNOS模型的精度最高,是对流层模型改正的最优选择。同时在选择改正模型时,应考虑测站高程的影响。 相似文献
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本文首先对精密单点定位原理进行阐述,其次对影响精密单点定位精度的各项误差进行分析,最后利用GNSS三频观测值不同组合方式对精密单点定位的误差进行研究,为提升GNSS精密单点定位精度提供参考。 相似文献
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基于文献多属性测度的新兴主题识别方法研究 总被引：1，自引：0，他引：1
对新兴主题的识别有助于科研人员把握相关领域的研究方向。针对目前新兴主题识别以关键词词频判断为主的局限性,构建文献多属性测度模型,利用高关注度、高成长潜力度以及高关联度指标对关键词进行有效识别并筛选,最终确定新兴主题。并以精密单点定位技术为例,说明此方法的实施步骤以及可行性。研究结果表明,根据多属性测度得到的精密单点定位的新兴主题更加明确,指示性强,与该领域现实研究状况(实时精密定点定位、定位误差修正以及模糊度固定等方面)具有较高的吻合度。 相似文献
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精密单点技术可以在获取定位上具有较高的精确性,并且简化了定位和计算过程,所需的成本比较经济性,在航道测量中的应用具有较大的发展空间,文章对精密单点定位技术的应用和优势进行了详细的分析,希望为航道测量发展带来帮助。 相似文献
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In this paper we address the problem of coarse synchronization of ultra wideband signals in the dense multipath channel, following the widely used hypothesis testing approach in which the uncertainty region for the timing offset is divided into a certain number of cells. We propose a novel strategy for the search of the correct cells, within the constant increment perspective. We show that under a simple model the proposed strategy achieves practically the minimum possible mean acquisition time, independently of the length of the channel impulse response, as opposed to previous constant increment approaches. A comparative analysis of the proposed strategy and another convenient one reveals that, strictly speaking, none of them can be considered optimum from the point of view of the mean acquisition time. The proposed method is advantageous from the point of view of computational complexity in the general case. Simulations with a realistic channel model confirm that the proposed strategy is very appropriate for the problem of coarse synchronization of UWB signals. 相似文献
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针对一类不确定非线性时滞系统,提出了一种具有确定逼近域的自适应模糊控制器的设计方案。在动态面控制（DSC）的基础上,通过时滞代换技巧,使得自适应模糊逼近器的输入为参考信号,从而可以明确定义逼近域,同时可以处理系统中完全未知的时滞信号。基于Lyapunov-Krasovskii范函,证明闭环系统所有信号为半全局一致有界的,并且跟踪误差可以收敛到原点附件的一个小邻域内。仿真结果进一步说明了该方法的有效性。 相似文献
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A delay distribution based stability analysis and synthesis approach for networked control systems 总被引：1，自引：0，他引：1
Communication delays in networked control systems (NCSs) has been shown to have non-uniform distribution and multifractal nature. This paper proposes a delay distribution based stability analysis and synthesis approach for NCSs with non-uniform distribution characteristics of network communication delays. A stochastic control model related with the characteristics of communication networks is established to describe the NCSs. Then, delay distribution-dependent NCS stability criteria are derived in the form of linear matrix inequalities (LMIs). Also, the maximum allowable upper delay bound and controller feedback gain can be obtained simultaneously from the developed approach by solving a constrained convex optimization problem. Numerical examples showed that the results derived from the proposed method are less conservativeness than those derived from the existing methods. 相似文献
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《Information processing & management》2023,60(4):103386
This article proposes a new framework to model a scenario in which First Responders, citizens, smart devices, or robots explore the environment in an emergency situation, i.e., after an earthquake, assessing damages and searching for people needing assistance. While moving, the agents observe events and exchange the information collected with other agents encountered: to this end, they use messaging systems purposely adapted to use point-to-point network connections to allow local data exchange between agents even when global network connections are not available. As is common in Delay Tolerant Networks, exchanged messages are locally stored: when a global network is available, the agents can upload all the information collected by themselves and other agents they encountered to a Control Room or a database in the Cloud. Differently from traditional DTN algorithms such as Epidemic and Spray&Wait, we propose a solution that keeps track of agents that shared information along the path and assess the quality of the information collected by multiple agents through a reputation-based mechanism that is safer than majority voting. A simulator compatible with OpenStreetMap is presented, as well as simulated experiments in two Italian towns to validate the feasibility of the approach. 相似文献
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研究了节点带有时滞且节点之间的通信也带有时滞的复杂动态网络的自适应同步问题。基于稳定性理论,设计了复杂网络同步的自适应控制器。该控制器结构简单,易于应用。最后,以环状耦合的时滞Lorenz系统为例进行数值仿真,检验了结果的正确性和设计方法的有效性。 相似文献
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Stability analysis of a class of stochastic differential delay equations with nonlinear impulsive effects 总被引：1，自引：0，他引：1
In this paper, we study stability of a class of stochastic differential delay equations with nonlinear impulsive effects. First, we establish the equivalent relation between the stability of this class of stochastic differential delay equations with impulsive effects and that of a corresponding stochastic differential delay equations without impulses. Then, some sufficient conditions ensuring various stabilities of the stochastic differential delay equations with impulsive effects are obtained. Finally, two examples are also discussed to illustrate the efficiency of the obtained results. 相似文献
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H.R. Marzban 《Journal of The Franklin Institute》2004,341(3):279-293
A method for finding the optimal control of a linear time varying delay system with quadratic performance index is discussed. The properties of the hybrid functions which consists of block-pulse functions plus Legendre polynomials are presented. The operational matrices of integration, delay and product are utilized to reduce the solution of optimal control to the solution of algebraic equations. Illustrative examples are included to demonstrate the validity and applicability of the technique. 相似文献
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本文利用锥理论和不动点指数定理,研究了一类具状态依赖时滞的脉冲微分方程的正周期解,获得了关于正周期解存在性的若干新的结果。 相似文献