共查询到20条相似文献,搜索用时 812 毫秒
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根据叶栅式反推力装置结构及其工作原理,建立了反推力装置运动学与动力学数学模型,以此为基础,取反推力装置对作动系统的最大负载力极小化为目标函数,装置各运动机构满足几何关系为约束条件,建立反推力装置结构优化模型。通过反推力装置运动学及动力学仿真,并分析在不同结构参数下反推力装置运动学及动力学特性,验证了所建立模型的合理性与正确性。在Matlab环境下采用惩罚函数法对反推力装置进行结构优化设计,结果表明:优化后的反推力装置正向最大负载力下降了24.5%,负向最大负载力下降了16.3%,且各个机构运动不出现干涉,整个反推力装置可正常工作。论文建模方法与优化结果可为反推力装置结构设计提供参考。 相似文献
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加工中心自动换刀装置提高了数控机床的加工效率,但由于加工中心换刀装置的动作控制比较复杂,包含机械、电气与PMC、液压和检测等技术,所以自动换刀装置的故障率比较高,主要介绍自动换刀装置的类别和控制,自动换刀装置的故障诊断方法,列举了自动换刀装置的一些常见故障及维修示例. 相似文献
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大型飞机增升装置技术发展综述 总被引:4,自引:0,他引:4
高效的增升装置是现代大型飞机研制中的关键技术之一。详细介绍了增升装置的原理和现代大型飞机常用的增升装置类型及其支撑与驱动机构。增升装置设计是一个多学科多目标的问题,从气动性能要求、噪声要求和结构重量要求几个方面介绍了增升装置的设计目标。研究了增升装置的发展历程和气动计算与实验方法,最后提出了增升装置的发展趋势和新技术。 相似文献
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飞机校靶装置是军用飞机校靶作业使用的专用保障设备,主要用于机载武器系统和相关系统安装轴线与机体基准轴线间的角度偏差的测量和校准,保障武器系统和相关系统的工作精度和准确性。飞机校靶装置从传统的靶板-望远镜系统发展到目前的新技术校靶装置,实现了技术和性能上的全面跨越。本文概述校靶装置技术发展,简要总结发展历程和发展规律;重点分析和比较3种新技术校靶装置,包括基于光电-惯性技术的光电-惯性校靶装置、基于摄影测量技术的摄影测量校靶装置和基于惯性技术的纯惯性校靶装置,进行技术分析和研究;对我国新型校靶装置发展提出建议。 相似文献
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Hydrogenated amorphous Si (a-Si:H) devices first made a significant impact in photovoltaic application, 70% of the photovoltaic solar cells produced in Japan in 1984 were a-Si:H. More recently, thin film transistor (TFT) and sensor devices have been developed for consumer and business products. The ability to produce large area uniform films of a-Si:H makes the application of TFTs and sensors well suited for input and output imaging devices such as image scanners, display and printers. This paper reviews the operation, material issues and physics of a-Si:H TFTs and sensors. The circuit and technology issues in large area systems incorporating these devices are described. 相似文献
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转台的限位保护装置包括电气限位保护装置和机械限位缓冲装置。根据转台运动方式及运动范围的不同,电气限位保护装置和机械限位缓冲装置的实现形式也有所区别,文中对此分别进行了详细介绍。 相似文献
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增升装置设计作为大型客机设计的关键技术之一,其设计水平的提升将极大提高飞机的整体性能。虽然先进增升装置方案朝着简单形式发展,但其设计目标将结合气动、机构、结构、噪声等复杂考虑因素,以达到最优的综合性能和提高飞行的安全性、经济性和舒适性,是个高难度多学科多约束耦合的设计问题。结合气动优化、机构设计、一体化研究等多方面增升装置设计难点进行论述,并提出相应解决方案,最终完成气动/机构一体化设计。分别回顾了干净构型到巡航构型的外形设计方法;起降构型的气动评估、优化方法;增升装置位置表达方法和机构设计研究现状。最后阐述了气动/机构一体化设计方法的思想,总结了国内外在该方向所进行的研究和取得的成果。 相似文献
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通过对COTS 器件使用风险和管理现状进行说明,对国内外电子器件管理要求的分析和研究,提出
了针对COTS 器件管理的适航要求建议,期望能达成限制机载设备中COTS 器件使用的风险,提升机载设备可
靠性及民用飞机安全性的目的。 相似文献
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Chen D.Y. Lee F.C. Blackburn D.L. Berning D.W. 《IEEE transactions on aerospace and electronic systems》1983,(6):840-847
The reverse-bias second breakdown (RBSB) characteristics of high power Darlington transistors are discussed. The Darlingtons investigated are rated at 400 V maximum voltage and 100 A maximum current. Devices with and without speed-up diodes (connected between the bases of the input and output transistors) were studied. A nondestructive system for characterizing the RBSB behavior of these devices is described. The RBSB behavior was found to vary unpredictably with varying reverse base current magnitude. It was also found that the RBSB behavior of the Darlingtons was a function of the forward base current magnitude. This is in marked contrast to what has been found for discrete devices. The presence of a speed-up diode also influenced the RBSB behavior of these devices. 相似文献
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Podlesak T.F. Carter J.L. McMurray J.A. 《Aerospace and Electronic Systems Magazine, IEEE》1990,5(12):25-28
A high-voltage opening switch that uses gate-turnoff thyristors (GTOs) in series and successfully operates at voltages higher than the rated voltage of the individual devices has been demonstrated. The switch design and construction are described, and experimental results are given. The demonstration system is rated at 5 kV and uses 1-kV devices. A larger 24-kV system is under design and will use 4.5-kV devices. In order to design the 24-kV switch, the safe operating area of the large devices must be thoroughly known 相似文献
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《中国航空学报》2022,35(11):113-154
Space missions have become diversified in recent years, where connection and separation devices play a crucial role as key components of various spacecraft. Traditional pyrotechnic devices have the advantages of large carrying capacity, rapid motion and functional reliability. However, their shortcomings such as great release shock, poor safety, unrepeatability and other prominent defects make them unsuitable for new generation spacecraft such as microsatellites to separate at low shock or lock repeatedly, etc. Therefore, it is necessary to develop space non-pyrotechnic low-shock connection and separation devices (SNLD) which are required for advanced aerospace missions. In this paper, the progress of the research on space non-pyrotechnic low-shock connection and separation technology (SNLT) is summarized and reviewed. Proceed from the principle of reducing shock for non-pyrotechnic devices, present studies are classified from the perspective of actuating technology and systematic designing methods. For non-pyrotechnic actuating techniques, according to different driving sources, the separation devices are classified into several main categories: electric, magnetic, gas and thermal actuating devices. The actuation principle and application prospect of separation techniques are introduced and the working process, dimension and mechanical properties of typical devices are compared and evaluated. For the systematic designing method, the common mechanism types of SNLDs are summarized according to the designing concept of reducing shock. Then connection configurations are classified according to the structural forms of connection devices, of which the principles, bearing capacities and general applications are discussed. This paper systematically summarizes the key problems, puts forward the future development trend of SNLT, and points out the breakthrough direction for related scholars. 相似文献