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81.
吴琛 《民用飞机设计与研究》2012,(1):32-34,39
地形提示和警告系统(TAWS)能够有效地避免可控撞地事故(CFIT)的发生,极大地提高了民用飞机飞行的安全性。目前,国外对TAWS的研究和应用比较成熟,而国内仍处于起步阶段。结合作者在设计中积累的经验,首先介绍了近地警告系统(GPWS)的功能特点,通过分析GPWS的应用局限性,给出了TAWS系统的发展历程。对TAWS的主要功能和应用进行了深入研究,重点分析了TAWS的前视功能。并在此基础上,给出了TAWS系统在实际应用过程中的优点和尚待解决的问题。最后,提出了适应民航系统未来发展的新一代TAWS系统的发展趋势。 相似文献
82.
Kang Lin Zewei Zheng Zhe Wu Qiang Wang 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2019,63(1):539-556
This paper presents the control scheme of a pseudo-satellite in situations where error constraints, uncertainties, and external disturbances occur. The control scheme of a pseudo-satellite includes planar path following control scheme and altitude control scheme. In order to control the altitude of a pseudo-satellite, the backstepping technique is used to control the quality of air in the air balloon. To deal with the error constrained requirements of a pseudo-satellite’s position, a tan-type barrier Lyapunov function (TBLF) is proposed and incorporated with the guidance control schemes. Adaptive fuzzy disturbance observers are presented to estimate uncertainties and external disturbances. Rigorous stability analysis proves that the altitude error of the pseudo-satellite can be uniformly bounded, and the position error of which can be maintained within the range of constrained requirements, while all closed-loop signals are uniformly bounded regardless of uncertainties and disturbances. 相似文献
83.
Tonggang Zhang Minyi Cen 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2008,41(11):1827-1835
Robust DEM co-registration for detecting terrain changes is an attractive but unresolved problem in both Remote Sensing and the Prevention and Mitigation of Hazards. Since robust DEM co-registration is an inherently very difficult problem, the algorithms developed are becoming more and more complicated. In this paper, a robust method for DEM co-registration is proposed, which integrates the least trimmed squares (LTS) estimator with the least Z-difference (LZD) algorithm. Moreover, a self-adaptive threshold based on the histogram of height differences is employed to identify the terrain changes automatically, which are the fundamental data for landslide assessment. The results of simulated experiments illustrate the robustness and accuracy of the new algorithm. 相似文献
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以勉宁高速公路为例,在1:2000的公路沿线地形平面图的基础上,利用AutoCAD和R2V软件对其进行预处理,然后在ArcGIS中建立高精度的DEM,通过DEM和公路沿线平面图的叠加,生成公路沿线单个三维地形,建立Oracle数据库存储二维和三维地形数据,并对其中三维数据进行了缓冲区、面积和体积计算等三维应用分析。 相似文献
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The necessity of improving the air traffic and reducing the aviation emissions drives to investigate automatic steering for aircraft to effectively roll on the ground. This paper addresses the path following control problem of aircraft-on-ground and focuses on the task that the aircraft is required to follow the desired path on the runway by nose wheel automatic steering. The proposed approach is based on dynamical adaptive backstepping so that the system model does not have to be transformed into a canonical triangular form which is necessary in conventional backstepping design. This adaptive controller performs well despite the lack of information on the aerodynamic load and the tire cornering stiffness parameters. Simulation results clearly demonstrate the advantages and effectiveness of the proposed approach. 相似文献
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