DECENTRALIZED ROBUST CONTROL FOR UNCERTAIN FLEXIBLE SPACE STATION

ＤＥＣＥＮＴＲＡＬＩＺＥＤＲＯＢＵＳＴＣＯＮＴＲＯＬＦＯＲＵＮＣＥＲＴＡＩＮＦＬＥＸＩＢＬＥＳＰＡＣＥＳＴＡＴＩＯＮＷａｎｇＱｉｎｇ；ＣｈｅｎＸｉｎｈａｉ（ＣｏｌｌｅｇｅｏｆＡｓｔｒｏｎａｕｔｉｃｓ，ＮｏｒｔｈｔｖｅｓｔｅｒｎＰｃｌｙｔｅｃｈｎｉｃａ...     

基于加速度测量的柔性智能桁架结构振动主动控制实验研究

本文在只能获得加速度时，通过改变Leunberger观测器的结构形式，基于模态滤波器技术、最优控制理论和计算机控制系统理论，采用独立模态空间控制策略进行了具有密集模态的空间柔性智能桁架的实时计算机振动主动控制实验研究。实验结果表明这种控制策略是行之有效的。     

全复合材料航天器结构探讨

质轻、价优是选择航天器结构材料的主要条件,用复合材料作航天器结构材料显然比金属材料优越。文中将通过美国海军研究所空间技术中心研制的全复合材料克莱门汀(Clementine)航天器,详细介绍采用复合材料作航天器结构件的利与弊。     

飞行器结构智能化研究及其发展趋势

智能化是飞行器结构发展的重要趋势，文中介绍了飞行器结构的智能化需求及其发展状况。阐述了飞行器的典型结构健康监测方法及其技术特征，讨论了飞行器主动变形结构的实现方法与途径，结合国内外研究情况，指出了飞行器结构智能化的可实现前景。     

中介逻辑的模型论性质

中介逻辑是朱梧槚与肖奚安合作创立的一个新的逻辑系统,该系统的创立有着很强的哲学背景,因此在创立后得到了很大的发展。但对于该系统语义的研究还不够广泛和深入。本文系统地研究了中介逻辑的模型论性质。第一部分系统地定义了中介逻辑模型论的一些概念:如语言、结构、解释、满足等,第二部分证明了对任一和谐理论,都可在其见证集的等价类上建立其模型。利用此定理,笔者证明了广义完全性定理,并由此证明了中介逻辑的可靠性与完备性。本文最后一部分讨论了中介模型论的其他重要性质。利用中介逻辑的完备性,本文证明了紧致性定理,即一理论有模型当且仅当其任一有穷子集有模型。文中还证明了中介逻辑的Lowenheim-Skolem-Tarski定理。     

大型土中浅埋可调式激波管及其在防护结构抗动载试验中的应用

本文对大型土中浅埋可调式激波管的主体结构、主要特点、测量手段、适用范围、以及在防护结构抗动荷载试验中的应用情况和发展前景作了简要介绍。     

替损件设计技术在飞机结构上的应用

详细叙述了替损件的设计思想和设计原则，以及在飞机结构上的应用实例。主梁的疲劳试验和翼身组合体的对比试验结果表明：替损设计可以大大提高结构的抗劳品质，并控制裂纹出现的部位，为实现结构长寿命高可靠的目标，提供了一条成功的途径。     

Very large space structures: Non-linear control and robustness to structural uncertainties

Very Large Space Structures (VLSS) are challenging systems to be controlled, due to their high flexibility. In particular, rapid attitude maneuvers can determine great oscillations on the flexible elements of a spacecraft (solar wings, antennas, booms). On account of this, in the last decades many researchers have developed different strategies to effectively damp the elastic vibrations by means of active vibration devices (such as piezo-electric patches) or by means of robust control algorithms. The approach suggested in this paper is different, since neither additional devices nor complex control laws are introduced. In fact, the complete model of the system (including rigid, elastic and orbital dynamics, coupled with control actions) is controlled by the non-linear attitude controller named state dependent Riccati equation, which will be based on a simplified version of the spacecraft model. The task to reduce the mutual interaction between rigid attitude and flexible dynamics is entirely transferred to a modification of the desired trajectory that must be tracked. This command shaping technique is based on the knowledge of the parameters (inertial and elastics) of the VLSS. Unfortunately these parameters are not always exactly known and, however, they may change over the time. On account of this a Monte Carlo analysis has been also performed, showing the robustness of the proposed control strategy to the structural uncertainties. The numerical simulations prove that this strategy, based on the joint application of two well-known yet simple techniques, produces accurate and robust results.     

空间高稳定碳/碳蜂窝夹层结构制备及性能

针对空间高稳定结构在极端环境下的灵敏度和稳定性需求，提出一种新型高稳定、高承载的轻质碳/碳(C/C)蜂窝夹层结构方案。碳/碳蜂窝夹层结构由化学气相渗透(CVI)致密化获得的整体碳/碳蜂窝和面板经胶粘剂粘接集成，通过评价蜂窝、面板以及夹层结构的内部质量、力学性能及热物理性能，展示了碳/碳蜂窝夹层结构在承载和尺度稳定性方面的优势。研究结果表明,典型特征碳/碳蜂窝承载性能稳定，平压强度＞10 MPa，L/W向剪切强度＞4 MPa，典型特征碳/碳蜂窝夹层结构热膨胀系数低，满足空间环境条件下面内热膨胀系数绝对值低于 1×10 -7 /℃的高稳定设计需求。     

Lagrangian coherent structures in various map representations for application to multi-body gravitational regimes

The Finite-Time Lyapunov Exponent (FTLE) has been demonstrated as an effective metric for revealing distinct, bounded regions within a flow. The dynamical differential equations derived in multi-body gravitational environments model a flow that governs the motion of a spacecraft. Specific features emerge in an FTLE map, denoted Lagrangian Coherent Structures (LCS), that define the extent of regions that bound qualitatively different types of behavior. Consequently, LCS supply effective barriers to transport in a generic system, similar to the notion of invariant manifolds in autonomous systems. Unlike traditional invariant manifolds associated with solutions in an autonomous system, LCS evolve with the flow in time-dependent systems while continuing to bound distinct regions of behavior. Moreover, in general, FTLE values supply information describing the relative sensitivity in the neighborhood of a trajectory. Here, different models and variable representations are used to generate maps of FTLE, and the resulting structures are applied to design and analysis within an astrodynamical context. Application of FTLE and LCS to transfers from LEO to the L₁ region in the Earth–Moon system are presented and discussed. In an additional example, an FTLE analysis is offered of a few stationkeeping maneuvers from the Earth–Moon mission ARTEMIS (Acceleration, Reconnection, Turbulence and Electrodynamics of the Moon's Interaction with the Sun).