大力推进民航雷达管制工作再上新台阶

经过十多年的建设和应用,我国雷达管制工作在保障民航飞行安全、提高空管运行能力、提升空管服务质量和强化空管综合保障能力等方面发挥了积极重要的作用。日前,总局空管局专门召开空管系统雷达管制工作会议,总结我国雷达管制工作取得的成绩,分析当前空管工作面临的形势,研究和     

管制运行风险的分析和控制

管制工作的核心就是保证飞行安全。随着我国空管事业的不断发展和飞行流量的快速增长,安全保障的难度和压力也愈来愈大,来自于人员、设备、环境、管理等各方面的不利因素随时都可能对空管运行安全造成巨大风险。要想保持空管运行安全平稳,作为管理者,就必须首先具备较强的风险分析和控制能力。因此,管制运行的过程,就其本质而言,     

带班主任的现场安全管理

作为最基层的安全管理实施者,带班主任在实施空中交通管制指挥的现场,如何运用安全管理经验,带领班组成员,在日常工作中不断完善保障手段,不断发展业务技能,对于保障空管安全、规范空管运行,提升服务质量,具有重要意义。     

加强安全管理提高空管基层单位安全保障水平

“十五”期间,是中国民航业发展最快的时期,也是民航空管系统发展最快的时期。空管系统的各项建设取得突破性进展,整体发展能力和综合保障能力有了很大提高,管制运行能力和服务水平不断提升,空管管理体制改革不断深化,空管文化建设不断加强,不仅为民航的飞行安全与正常做出了应     

加强设备运行风险防控 实现温州空管科学持续发展

近年来,随着航班量的不断增长、雷达管制和RVSM的相继实施,空中交通管制工作对于设备的依赖性越来越大,设备运行风险对空管安全工作的影响也越来越直接。对设备运行保障情况进行风险分析和评估,采用行之有效的管理办法以达到风险防控的目的,不仅是空管安全生产工作的需要,也是空管实现科学持续发展的前提和必然要求。     

树立和谐文化发展观不断加快空管文化建设步伐

“十一五”时期是全面建设小康社会，加快推进社会主义现代化建设的重要机遇期，是我国由民航大国向民航强国发展的关键时期，是民航系统加快发展，基本实现空管现代化最为关键的阶段。当前，如何在不断满足地区空中交通保障需求中提升安全管理水平、提高空中交通管制服务质量，实现民航空管现代化目标，走科学发展之路，是民航空管系统目前亟待解决的问题，[第一段]     

日本空中交通管制情况概述与思考

日本是世界航空强国,空中交通管制理念发达、手段多样,空管保障能力强,有许多值得我们学习和借鉴的地方。本文初步探讨日本现行空中交通管制体系和相关空管技术,提出了提高我国空管保障能力的相关建议。     

空中交通管制MORT安全评估模型

随着对系统安全和安全文化理论的认识加深，我国民航的空中交通安全管理已发展为一项安全系统工程。如何通过有效的管理实现空管系统人、机、境诸要素的协调运作，这是保证系统安全性、可靠性的关键。因此，对空管系统安全评估的重点是对管理因素的评价。本文通过管理疏忽与危险树(MORT)模型建立管制安全评估系统，就如何立足管理角度开展安全评估问题进行了研究。     

提高执行力——雷达管制现场运行管理初探

随着改革开放的进一步深入,我国的民航运输事业也步入了发展的快车道,航空运输总周转量、飞行架次等各项运行指标年均以两位数的幅度攀升。近年来,为了应对和适应日益增长的空中交通流量,提升空管保障水平,部分管制中心开始实施雷达管制,在缩小了安全间隔的同时增强了安全余度,     

浅析如何实现班组的安全管理

安全工作是空管稳定发展的基础工作,安全管理是空管的永恒主题。空管系统要实现可持续发展,加强管理固然重要,然而创新安全工作的新思路更为重要。安全管理要求我们在贯彻“安全第一,预防为主”方针的实践中,必须深刻地认识到“安全是基础,设备是重点,管理是关键,人员是保证”的真谛。对空管保障安全一线的管制班组的管理尤为重要。管制带班主任多是管制员,不是管理专业出身,而管制现场的管理也多是借鉴企业管理,     

Optimal Control of a Programmed Turn of a Spacecraft

A problem of optimal turn of a spacecraft is considered. The time of turn is minimized, as well as the functional having a meaning of the propellant consumption. An analytical solution to the problem stated is derived. It is demonstrated that the solution optimal in this sense belongs to a class of two-impulse controls, under which a spacecraft executes the turn along the trajectory of its free motion. The solution obtained in this paper differs from earlier available solutions considerably. The estimations of the propellant consumption for a realization of the programmed turn are made.     

Motion of a Planet with a Complex Structure

The motion of a planet consisting of a mantle and a core (solid bodies) connected by a viscoelastic layer and interacting with each other and an external point mass by the law of gravitation is considered. The mutual motions of the core and mantle are investigated assuming that the centers of mass of the planet and external point mass moves along undisturbed Keplerian orbits around the common center of mass of the system. The planetary core and mantle have an axial symmetry and different principal moments of inertia, which leads to a displacement of the center of mantle relative to the center of core and to their mutual rotations. The results obtained on the basis of averaged equations are illustrated by the example of the Earth–Moon system.     

Identification of failures in a set of sensors of a spacecraft

A method to find and identify failures in a spacecraft’s set of sensitive elements that measure vector quantities of different nature is discussed.     

一个带间隙连接结构对梁基频漂移影响研究

文章以一端夹支、另一端带套筒连接结构的梁作为研究对象,通过在连接结构中引入间隙非线性因素,分别研究了在连接结构处有无预紧力两种情况时在均布载荷作用下梁的非线性幅频响应。同时,利用改进的振型转化法及连续振型法对系统进行建模,采用伽辽金近似得到系统的非线性受迫振动方程;针对实际算例,用龙格-库塔法得到了其数值解,讨论了此算例梁的频率漂移结果,从而得到了对研究航天器地面振动试验中的频率漂移现象有价值的结论。     

Peristaltic transport of a viscoelastic fluid in a channel

This paper is devoted to the study of the peristaltic transport of viscoelastic non-Newtonian fluids with fractional Maxwell model in a channel. Approximate analytical solutions have been constructed using Adomian decomposition method under the assumption of long wave boundary layer type approximation and low Reynolds number. The effects of relaxation time, fractional parameters and amplitude on the pressure difference and friction force along one wavelength are received and analyzed. The study is limited to one way coupling model with forward effect of the fluid on the peristaltic wall. It is evident from the result that pressure diminishes with increase in relaxation time and the effects of both fractional parameters on pressure are opposite to each other. The influences of these parameters on friction force are opposite to that of pressure.     

某型卫星有效载荷支架振动抑制

某型号卫星的有效载荷支架结构在验收级振动试验时振动超标。在对结构不做大的修改的前提下，采用约束阻尼层用对原结构进行处理。对不同的约束阻尼层方案采用有限元方法进行计算，综合考虑各种影响因素，如阻尼比和附加质量等，得到合理的约束阻尼减振方案，并在结构星上进行试验，确定最终实施方案。实施方案后，正样星在0．1g振动条件下，最大振动幅值下降了22．3％，保证了卫星的顺利发射。该卫星已经成功发射，并且在轨运行正常。该问题的成功解决和解决问题的方法与过程为今后解决类似问题提供了经验。     

Application of a magnetohydrodynamic element in the control loop of a rotating spacecraft with a spike antenna

The problem of stabilization of a rotating spacecraft with a flexible spike antenna located along the axis of spacecraft rotation is considered. A magnetohydrodynamic element is used as a final-control element in the control loop of spacecraft attitude, and the solar direction sensor serves as a measuring device. At the first stage of investigation, the problem of stability is considered for stationary and non-stationary modes of rotation of the spacecraft with a flexible antenna and with a cavity partially filled with a low-viscosity liquid.     

Equilibrium positions of a weight on a cable fixed to a dumbbell-shaped space station moving along a circular geocentric orbit

The motion of a space object in the gravitational field of the Earth is considered. The object consists of an extended space station and a weight, which is free to move along the cable fixed to the ends of the station. It is assumed that the station is composed of two masses coupled by a weightless rod, while the cable is weightless and non-stretched. The equations of motion of such a system are derived for the case when the motion proceeds in a single plane, while the center of mass of the system moves along a circular geocentric orbit. The conditions of the cable tension (conditions of being on tie) are derived. The phase portrait of the weight motion along the cable is constructed when the station is oriented to the attracting center or is perpendicular to this position. The possibility to leave the tie in this case is analyzed. Equilibrium configurations of the system are found, i.e., such motions of the object under consideration at which the weight does not change its position relative to the station. Lyapunov stability of such configurations is analyzed for two situations: when the station is composed of equal masses and when masses at the ends of the station are different. In particular, for the case of different masses it is established that there exist such positions of equilibrium at which the dumbbell is located at an angle to the direction to the attracting center. In some cases these positions can be stabilized (if the weight is fixed on the cable).     

Station keeping of a solar sail around a Halo orbit

Solar sails are a concept of spacecraft propulsion that takes advantage of solar radiation pressure to propel a spacecraft. Although the thrust provided by a solar sail is small it is constant and unlimited. This offers the chance to deal with novel mission concept. In this work we want to discuss the controllability of a spacecraft around a Halo orbit by means of a solar sail. We will describe the natural dynamics for a solar sail around a Halo orbit. By natural dynamics we mean the behaviour of the trajectory of a solar sail when no control on the sail orientation is applied. We will then discuss how a sequence of changes on the sail orientation will affects the sail's trajectory, and we will use this information to derive efficient station keeping strategies. Finally we will check the robustness of these strategies including different sources of errors in our simulations.