Ship formation control via output feedback with unknown dynamics

研究了仅利用相对位置信息和相对航向信息的船舶编队输出反馈控制问题.首先使用leader-follower策略,建立了船舶编队的运动学模型.然后应; 用微分同胚变换将系统解耦成3个子系统.根据船舶低频运动的特点,在跟随船水动力学模型中粘性水动力和力矩未知以及所有船舶速度都不可测量的假定下,提出; 了一种高增益广义比例积分观测器来估计这些未知和不可测量动态.在高增益广义比例积分观测器的基础上,分别设计了线性输出反馈控制器和输入饱和受限的输出; 反馈控制器,并分析了闭环系统的稳定性.最后仿真结果表明了方法的有效性.This paper focuses on the ship formation control problem via output; feedback, with only the information of the relative positions and; relative heading angles available. Firstly, the kinematic model of the; ship formation is established using the leader-follower strategy. Then; the system is decoupled into three subsystems via the diffeomorphism; transformation. According to the low frequency characteristics of the; ship motion, and the assumption that the viscous hydrodynamic forces and; moments in the hydrodynamic models of the follower ships are unknown and; the velocities of all the ships are unmeasurable, the high-gain; generalized proportion-integral observers are proposed to estimate the; unknown and unmeasurable dynamics. On the basis of the high-gain; generalized proportion-integral observers, the linear output feedback; controllers and the output feedback controllers with input saturation; are designed respectively, and the stability of the closed-loop systems; is analyzed. Finally, the simulation results show the effectiveness of; the proposed approach.国家自然科学基金项目; 福建省自然科学基金项

多艘拖轮协助大型船舶靠泊的编队控制方法

为了研究多艘拖轮协助欠驱动大型船舶靠泊的控制,提出了一种采用拖轮编队来解决大型船舶靠泊问题的控制方法.在拖轮的水动力学模型中,将大型船舶对拖轮的反作用力视为未知输入,给出了一种干扰估计误差方程和原状态方程形成互联系统的干扰观测器.该干扰观测器使得拖轮速度实际值与期望值误差能够快速收敛.在干扰观测器的基础上给出了拖轮编队控制器设计,并分析了闭环系统的稳定性.仿真结果验证了该方法的有效性.国家自然科学基金(61374037

Analysis of Active Power Measurement Error

用对称分量分析了三序功率与三相功率间的关系,得出三相功率是同一相序的电压与电流的对称分量函数;三相电路平衡时,用两瓦法能正确测量三相三线电路功率,当三相四线电路不平衡时,用两瓦法测量功率存在误差。Using symmetrical components,this paper analyzes the relationship between 3-sequence power and 3-phase power and concludes that 3-phase power is a function of the symmetrical components of voltages and currents of the same phase sequence.When the 3-phase circuit is in a balanced condition,we can correctly measure the power of the 3-phase 3-wire circuit in the 2-bush method.If the 3-phase 4-wire circuit is not balanced,there might be errors with the power measurement in the 2-bush method

ダイ40ジ ナンキョク チイキ カンソクタイ キショウ ブモン ホウコク 1999

これは,第40次南極地域観測隊気象部門が,1999年2月1日から2000年1月31日まで,南極昭和基地において気象観測を行った結果の報告である.気象観測の方法,測器,統計方法等は,第39次隊とほぼ同様である. 越冬期間中,特記される気象現象として,次のものがあげられる.1) 地上気象観測において,7月,12月,1月の気温,5月,10月,12月,1月の気圧が平年に比べ著しく低かった.10月5日に最低海面気圧932.1hPa(歴代2位)を記録した.ブリザードは,A級が4回,B級が10回,C級が11回の計25回あり,平年並みであった.2) オゾン全量観測において,昨年に引き続き大規模なオゾンホールを観測し,11月の月平均オゾン全量は過去最低を記録した.その後,12月中旬にオゾンホールは消滅したが,オゾン全量値の回復は過去一番遅かった.3) それに伴い,成層圏の昇温が遅れ,春季に下部成層圏で記録的に低い月平均気温を観測した.4) エアロゾルゾンデ観測において,春期南極上空で形成されるオゾンホールの重要要因となっていると思われる極成層圏雲(PSCs)の雲粒子の分布状況を観測した.5) 地上オゾン濃度観測において,観測を始めた第38次隊以来連続して地上オゾン濃度急減現象を観測した.This report presents the results of meteorological observations at Syowa Station from February 1, 1999 through January 31, 2000, carried out by the 40th Japanese Antarctic Research Expedition (JARE-40). The meteorological observation method, measuring instruments, means to compile statistics, and other aspects of the work were almost the same as those used by the 39th Japanese Antarctic Research Expedition. Remarkable weather phenomena during the wintering period are as follows: 1) In the surface weather observations, in July, December and January, the atmospheric temperature was significantly lower recorded compared to normal average years, and also the atmospheric pressure was significantly lower in May, October, December and January. The lowest sea level pressure, 932.1hPa was recorded during a severe blizzard on October 5 for the JARE-40 period (the 2nd lowest in history). There were 25-blizzards of which 4 were class A, 10 class B, and 11 class C, the same level as in a normal year.2) As a result of total ozone observation, the large-scale ozone hole was observed, as in the previous year, and the monthly average amount of total ozone in November recorded the lowest ever. Then, the ozone hole disappeared in mid-December, however, the recovery of the total amount of ozone was the slowest in years.3) Because, the temperature rise for the stratosphere was delayed, record-low monthly average temperature was observed in the lower stratosphere in springtime.4) By observing with an aerosol sonde, we observed cloud particles of polar stratospheric cloud (PSCs), which are thought to be the most important cause of ozone holes formed in the Antarctic lower stratosphere in springtime.5) In observation of surface ozone concentration, the rapid decrease of surface ozone concentration has been observed continuously, since JARE-38 started this observation

中国物理海洋学研究70年：发展历程、学术成就概览

本文概略评述新中国成立70年来物理海洋学各分支研究领域的发展历程和若干学术成就。中国物理海洋学研究起步于海浪、潮汐、近海环流与水团,以及以风暴潮为主的海洋气象灾害的研究。随着国力的增强,研究领域不断拓展,涌现了大量具有广泛影响力的研究成果,其中包括:提出了被国际广泛采用的"普遍风浪谱"和"涌浪谱",发展了第三代海浪数值模式;提出了"准调和分析方法"和"潮汐潮流永久预报"等潮汐潮流的分析和预报方法;发现并命名了"棉兰老潜流",揭示了东海黑潮的多核结构及其多尺度变异机理等,系统描述了太平洋西边界流系;提出了印度尼西亚贯穿流的南海分支(或称南海贯穿流);不断完善了中国近海陆架环流系统,在南海环流、黑潮及其分支、台湾暖流、闽浙沿岸流、黄海冷水团环流、黄海暖流、渤海环流,以及陆架波方面均取得了深刻的认识;从大气桥和海洋桥两个方面对太平洋–印度洋–大西洋洋际相互作用进行了系统的总结;发展了浅海水团的研究方法,基本摸清了中国近海水团的分布和消长特征与机制,在大洋和极地水团分布及运动研究方面也做出了重要贡献;阐明了南海中尺度涡的宏观特征和生成机制,揭示了中尺度涡的三维结构,定量评估了其全球物质与能量输运能力;基本摸清了中国近海海洋锋的空间分布和季节变化特征,提出了地形、正压不稳定和斜压不稳定等锋面动力学机制;构建了"南海内波潜标观测网",实现了对内波生成–演变–消亡全过程机理的系统认识;发展了湍流的剪切不稳定理论,提出了海流"边缘不稳定"的概念,开发了海洋湍流模式,提出了湍流混合参数化的新方法等;在海洋内部混合机制和能量来源方面取得了新的认识,并阐述了混合对海洋深层环流、营养物质输运等过程的影响;研发了全球浪–潮–流耦合模式,推出一系列海洋与气候模式;发展了可同化主要海洋观测数据的海洋数据同化系统和用于ENSO预报的耦合同化系统;建立了达到国际水准的非地转(水槽/水池)和地转(旋转平台)物理模型实验平台;发展了ENSO预报的误差分析方法,建立了海洋和气候系统年代际变化的理论体系,揭示了中深层海洋对全球气候变化的响应;初步建成了中国近海海洋观测网;持续开展南北极调查研究;建立了台风、风暴潮、巨浪和海啸的业务化预报系统,为中国气象减灾提供保障;突破了国外的海洋技术封锁,研发了万米水深的深水水听器和海洋光学特性系列测量仪器;建立了溢油、危险化学品漂移扩散等预测模型,为伴随海洋资源开发所带来的风险事故的应急处理和预警预报提供科学支撑。文中引用的大量学术成果文献(每位第一作者优选不超过3篇)显示,经过70年的发展,中国物理海洋学研究培养了一支实力雄厚的科研队伍,这是最宝贵的成果。这支队伍必将成为中国物理海洋学研究攀登新高峰的主力军

Understanding Science from the Perspective of Practice

对马克思关于实践与科学的关系有两种解读,即认识论解读和存在论解读。是否在哲学的逻辑基点上把“实践的观点“作为理解科学的思维方式是它们之间的原则区别。马克思从“现实的人“出发阐述了实践对科学的存在论关系,认为实践对于科学具有综合的意义,“历史境遇“、交往、工业、技术等在存在论上对于科学活动具有先在性,形成了马克思的“实践论科学观“。当代西方的“诠释学的现象学“既重视分析作为实体的科学实践,更强调将实践的观点作为理解科学的思维方式。在具体内容上和马克思的“实践论科学观“形成互补,同时也表征了马克思以实践的观点理解科学在哲学原则上的当代性。There are two ways to understand Marx's view on the relationship between practice and science,namely from points of view of epistemology and ontology respectively.Their fundamental difference lies in wether they take "perspective of practice" as their logical starting point.Based on the concept of "real individual" ,Marx's "practice-oriented viewpoint of science" formulated the relationship between practice and science in the domain of ontology.For instance,practice is inherently related to science; "historical situation" ,communication,industry,technology and capital are primordial to science.In contemporary western countries,"hermeneutic phenomenology" emphasizes on analyzing the science practice as entity and taking the perspective of practice as means of understanding science."Hermeneutic phenomenology" ,therefore,not only complements Marx's "practice-oriented viewpoint of science" in contents,but also indicates that Marx's perspective on science develops with the times.国家社会科学基金项目“当代西方诠释学的现象学科学哲学研究”(项目批准号:09BZX022);2009年教育部人文社会科学研究规划项目“近20年来西方科学哲学的发展及对我国科学哲学学科建设的启示”的阶段性成

Statistics and Analysis of the Journal Philosophy of Science of 1988-2007

PHIlOSOPHy Of SCIEnCE是美国科学哲学协会的官方刊物,美国科学哲学协会“两年一度会议记录“占所发表的论文总量的比例较高,PHIlOSOPHy Of SCIEnCE呈现出的发展态势基本反映了美国科学哲学的现状。从1988-2007年发表论文关键词的统计看,量子理论的研究最受关注,进化、生物学是另一个研究热点,逻辑、数学、认知科学等方面的研究也备受关注;从影响力的角度上看,在1996-2007年间,PHIlOSOPHy Of SCIEnCE的影响因子常年保持在0.3以上,但在JCr公布的2000-2007年影响因子排名上,其下降态势十分明显;在作者方面,90%以上的论文为个人独立成果。Philosophy of Science is the official journal of the Philosophy of Science Association (PSA) of America.Papers from the PSA conference proceedings take a considerable proportion of all the published articles.The developmental trend of Philosophy of Science reflects, on the whole, the current situation of American philosophy of science.Statistics of the of articles during 1988-2007 show that quantum theory has drawn the most attention; evolution and biology are important areas of researches;and logic, mathematics and cognitive science also attract much interest.In terms of influence, the impact factor of Philosophy of Science stood above 0.3 during 1996-2007.However, the ranking lists released by JCR show that Philosophy of Science declined significantly in ranking during 2000-2007.As far as authors are concerned, more than 90% articles were completed individually.2009年教育部人文社会科学研究规划课题“近20年来西方科学哲学的发展及对我国科学哲学学科建设的启示”(09YJA720018)的部分成

全球数字广播系统音频编码器的软件实现

全球范围的数字广播系统DRM(Digital Radio Mondiale),是一种针对30MHz以下频段的数字声音广播系统。和传统广播系统相比,DRM数字广播系统在声音质量上是模拟调幅广播无法比拟的。这其中的关键之一在于DRM系统引入了新的信源编解码技术——MPEG-4标准的AAC(Advanced Audio Coding,先进音频编码)。在分析符合DRM标准的AAC音频编码器原理基础上,提出了一种改进的离散余弦变换算法,并在PC上实现了基于该算法的AAC音频编码器。实验表明,该软件编码器能够满足D