小型月球探测器高精度姿态指向控制

针对小型月球探测器三轴姿态高指向精度和高稳定度的要求 ,采用欧拉动力学和四元数方法描述 ,建立了小型月球探测器环月阶段动力学模型 ,分析了由 3个轻型反作用轮正交安装组成的姿态稳定控制系统 ,给出了一种拟PD姿态指向控制规律。对所设计的指向控制律进行了数学仿真 ,结果表明可达到 0 .0 1°/s的稳定度和 0 .3°的指向精度 ,验证了该控制规律的可行性。     

RBF网络及其在卫星姿态控制中的应用

提出了一种基于RBF网络扰动力矩补偿的控制技术，通过在传统PID控制的基础上，引入RBF网络补偿环节，进一步抑制了扰动力矩的影响，提高了卫星姿态控制精度，首先给出了RBF网络的学习算法，然后根据全补偿原则设计了神经网络补偿姿态控制方案，最后结合某型卫星的姿态控制系统设计实例，进行了数学仿真，结果表明：有RBF网络补偿的系统，姿态的稳态精度得到了明显的改善。     

Surveying instructor and learner attitudes toward e-learning

The trend of using e-learning as a learning and/or teaching tool is now rapidly expanding into education. Although e-learning environments are popular, there is minimal research on instructors’ and learners’ attitudes toward these kinds of learning environments. The purpose of this study is to explore instructors’ and learners’ attitudes toward e-learning usage. Accordingly, 30 instructors and 168 college students are asked to answer two different questionnaires for investigating their perceptions. After statistical analysis, the results demonstrate that instructors have very positive perceptions toward using e-learning as a teaching assisted tool. Furthermore, behavioral intention to use e-learning is influenced by perceived usefulness and self-efficacy. Regarding to learners’ attitudes, self-paced, teacher-led, and multimedia instruction are major factors to affect learners’ attitudes toward e-learning as an effective learning tool. Based on the findings, this research proposes guidelines for developing e-learning environments.     

CZ－2CFP离轨方案分析

针对ＣＺ－２Ｃ／ＦＰ（分配器）的离轨要求，对被动和主动两种离轨方案进行计算、分析和比较，最后选择主动离轨方案对ＣＺ－２ＣＦＰ在卫星分离后进行离轨，即在卫星分离后，用箭上姿控喷管将ＦＰ调姿至所需姿态，然后用剩余推进剂离轨，改变ＦＰ的轨道，使近地点高度降低，加快轨道衰减，达到离轨目的。这种主动离轨方案直接利用箭上姿控系统进行离轨，无需重新设计新的离轨系统，从而保持了原系统的简单和可靠并可以节省大量的经费。而且，主动离轨方案可以将ＦＰ同其它在轨飞行物之间的碰撞概率减小两个数量级还多，这对保证卫星的安全有很大的好处。     

A楼·B楼·C楼--同济校园新建筑评述

同济大学校园在几十年发展过程中出现了各种形式的个性建筑。从20世纪50年代的文远楼到80年代的建筑城规学院明成楼再到21世纪的建筑城规学院新楼，代表了三个历里时期的建筑特色，并共同坚持着同一种精神，那就是勇于创新，紧跟潮流的时代精神。     

Attitude Controller Design on Variable Rolling Velocity Aerocraft Based on ATmega16

1 Introduction Owing to the effect of crosswind, initial disturbance and the deviation of engine parameters.etc in the initial aviation, variable rolling velocity aerocraft will produce attitude angle deviation (AAD) in the ideal orientations. It must control the attitude of the aerocraft, accordingly, AAD of aerocraft can be amended.Angle stabilization control system is used for the attitude control of rolling aerocraft by this paper. This control system is generally located in the control…     

从吕胜中作品“众”看当代实验艺术中的辩证思想

在当代,艺术创作已不再局限于传统绘画的方式,而是用更多元的语言来表述。借助数字技术和新材料应用,通过纪实或观念影像、装置雕塑、大地艺术、行为艺术等表达观点与情感。艺术家吕胜中作品——"众"的创作灵感根植于对中国民间美术的深刻认识和西方当代艺术的体悟,包涵了辩证统一的哲学思想。他的艺术态度是为实现以国际当代多元文化为背景和中国深厚传统文化为土壤,开辟具有中国式、国际化当代艺术所坚持的实验艺术精神。     

Distributed attitude synchronization using backstepping and sliding mode control

We consider the problem of attitude synchronization for systems of rigid body agents with directed topologies. Two different scenarios for the rotation matrices of the agents are considered. In the first scenario, the rotations are contained in a convex subset of SO(3), which is a ball of radius less than π/2, whereas in the second scenario the agents are contained in a subset of SO(3), which is a ball of radius less than π. Using a control law based on backstepping and sliding mode control, we provide distributed, semi-global, torque control laws for the agents so that the rotations asymptotically synchronize. The control laws for the agents in the first scenario only depend on the relative rotations between neighboring agents, whereas the control laws in the second scenario depend on rotations defined in a global coordinate frame. Illustrative examples are provided where the synchronization is shown for both scenarios.     

爪型航天器对接机构容差性能分析

在航天器对接结构优化设计问题的研究中,航天器对接机构对在轨服务有重要作用,爪型航天器对接机构是新型对接机构.新型对接机构对对接任务的初始位姿偏差的容差性能需要进行研究,对接机构的性能将直接决定对接任务的成败.针对爪型对接机构的容差性能这一问题,利用三维造型软件Pro/E和机械系统动力学仿真分析软件Adams建立了爪型航天器对接机构虚拟样机模型,通过改变单参数变量方法进行对接过程仿真,对仿真结果进行对比分析,可为爪型对接机构的设计、对接初始条件确定和控制策略的制定提供参考.