Consensus under general convexity

A method is proposed to characterize contraction of a set through orthogonal projections. For discrete-time multi-agent systems, quantitative estimates of convergence (to a consensus) rate are provided by means of contracting convex sets. Required convexity for the sets that should include the values that the transition maps of agents take is considered in a more general sense than that of Euclidean geometry. © 2007 IEEE.

Temperature and power-density-dependent inter-shell energy states in InAs/GaAs quantum dots

We have investigated the evolution of exciton state filling in InAs/GaAs quantum dot (QD) structures as a function of the excitation power density by using rnicro-photoluminescence spectroscopy at different temperatures. In addition to the emission bands of exciton recombination corresponding to the atom-like S, P and D, etc. shells of QDs, it was observed that some extra states V between the S and P shells, and D' between the P and D shells appear in the spectra with increasing number of excitons occupying the QDs at a certain temperature. The emergence of these inter-shell excitonic levels is power density and temperature dependent, which is an experimental demonstration of strong exciton-exciton exchange interaction, state hybridization, and coupling of a multi-exciton system in QDs. (c) 2006 Elsevier B.V. All rights reserved.

Temperature and power-density-dependent inter-shell energy states in InAs/GaAs quantum dots

We have investigated the evolution of exciton state filling in InAs/GaAs quantum dot (QD) structures as a function of the excitation power density by using rnicro-photoluminescence spectroscopy at different temperatures. In addition to the emission bands of exciton recombination corresponding to the atom-like S, P and D, etc. shells of QDs, it was observed that some extra states V between the S and P shells, and D' between the P and D shells appear in the spectra with increasing number of excitons occupying the QDs at a certain temperature. The emergence of these inter-shell excitonic levels is power density and temperature dependent, which is an experimental demonstration of strong exciton-exciton exchange interaction, state hybridization, and coupling of a multi-exciton system in QDs. (c) 2006 Elsevier B.V. All rights reserved.

Radar interferometer measurements of space debris using the Evpatoria RT-70 transmitter

The ability of the Evpatoria RT-70 radar complex to perform research on space debris was investigated in four trial experiments during 2001-2003. The echo-signals of 25 objects at geostationary, highly elliptical and medium-altitude orbits were recorded on magnetic tapes at radio telescopes in Russia, Italy, China and Poland. The multi-antenna system configuration gives potential to supplement the classic radar data with precise angular observations using the technique of Very Long Baseline Interferometry. The first stage of such processing was fulfilled by the correlator in N. Novgorod, Russia. The cross-correlation of transmitted and received signals was obtained for the 11 objects on the Evpatoria-Bear Lakes, Evpatoria-Urumqi and Evpatoria-Noto baselines. This activity also promoted developing the optical observations of geostationary objects, conducted for the improvement of the radar target ephemerides. (C) 2004 COSPAR. Published by Elsevier Ltd. All rights reserved.

面向流程企业的可配置MES体系结构

过程系统工程的概念内涵将企业的经营管理、供应链和MES的运作紧密联系在一起,当企业组织结构调整、工艺过程改造、产品方案变动等发生时,要求MES系统具有对工厂过程和业务过程持续变化的适应能力。本文提出了一种面向流程企业的可配置MES体系结构,包含模型层、协同平台层和功能层3个配置层次,通过模型层实现业务功能与工厂描述分离;协同平台层实现业务逻辑与技术支撑分离,以及实现整体过程协同和全局优化;功能层实现不同厂商产品间标准化的功能接口。最后,以基于可配置体系结构的MES产品(SMES)为例,分析了各层次的实现方式以及对流程企业业务持续变化的适应性验证。

Observation and theoretical analysis for the sand-waves migration in the North Gulf of South China Sea

According to the environmental characteristic of the north gulf of South China Sea, a quasi-3D mechanics model has been built for simulating the small scale sand-waves migration in the seas of southwest of Hainan Island. Based on the submarine micro-geomorphic data induced by multi-beam system and hydrographic survey record, the migrations of the sand-waves in the study area are predicted. The results show that calculation is consistent with the observation data in the groove of sand ridge, but not well in the crest of sand ridge. It is indicated that the mechanics model should be used to predict the migration of the small scale sand-waves which are dominated by bed load in the seas. This paper is very meaningful to project the route of submarine pipeline.

三维环境中基于ESMF的多机器人协作观测方法

提出了一种基于扩展集员估计（ESMF）的多机器人协作观测方法，该方法将多机器人之间的观测数据融合过程嵌入到估计过程当中，从而减少了数据处理的过程，增强了算法的快速性。同时，这种方法在实现协作观测时只需要协作机器人传送观测信息而不是整个的估计信息，因此可以减轻多机器人系统的通信负担。除此之外，该方法在融合多机器人的观测数据过程中避免了多余的近似过程，增加了观测的准确性。最后，给出了三维环境下的仿真结果，验证了方法的可行性。

基于评价选择策略的Internet多机器人协作控制研究

针对Internet多机器人系统中存在的操作指令延迟、工作效率低、协作能力差等问题,提出了多机器人神经元群网络控制模型。在学习过程中,来自不同功能区域的多类型神经元连接形成动态神经元群集,来描述各机器人的运动行为与外部条件、内部状态之间复杂的映射关系,通过对内部权值连接的评价选择,以实现最佳的多机器人运动行为协调。以互联网足球机器人系统为实验平台,给出了学习算法描述。仿真结果表明,己方机器人成功实现了配合射门的任务要求,所提模型和方法提高了多机器人的协作能力,并满足系统稳定性和实时性要求。

一种星球探测系统多机器人通信机制研究

分析了一种可重构星球探测系统中多机器人通信的特点.根据多机器人系统的功能要求,在TDMA(时分多址)分时共享信道原理和击鼓传花机制的启发下,提出了一种新颖的多机器人无线通信机制.详细介绍了该通信机制和通信协议.仿真和通信实验同时验证了该机制的可行性和实用性.

灾难救援机器人研究现状、关键性能及展望

对日本、美国和中国等国家灾难救援机器人的研究现状和研究计划进行综述。根据世界各国救援机器人技术的研究现状,结合救援机器人在实际应用中取得的经验和教训,归纳和总结出救援机器人的关键性能为：存活能力、运动能力、感知能力、通信能力和作业能力。研究结果表明,灾难救援机器人研究逐步从试验研究转入到实际应用,多种技术融合化、多智能体网络化是今后灾难救援机器人研究的发展方向。防灾、减灾和救灾事关人民生命和财产安全,是国家公共安全的重要组成部分。救援机器人技术是国家发展迫切需要的战略必争的核心技术之一,将在国民经济和安全中起着重要作用并具有重大的战略意义。

轮式移动机器人轨迹跟踪的最优控制

深入分析了轮式移动机器人的运动状态,建立了WMR路径偏差系统的非线性数学模型。应用小偏差线性化理论,将该多输入多输出非线性系统简化成一个单输入单输出线性系统。然后基于线性二次型调节器理论进行了系统最优控制器的设计,并针对该理论中加权矩阵Q与R难以确定的问题,从控制效果出发,采用自适应遗传算法对其进行了优化。实现了移动机器人对预定轨迹的满意鲁棒跟踪,同时满足了实时性要求。实验结果证明了该方法的正确性与实用性。

可重构星球探测机器人的OpenGL仿真实验平台研究

采用基于Visual C++和OpenGL的建模和运动仿真方法,对可重构星球探测机器人系统的三维运动仿真实验平台进行了研究,建立了一个多机器人系统的仿真实验平台。开发的实验平台可用于探索和验证机器人系统的工作原理、工作空间、多机器人协调算法、重构方法、系统集成技术等。在该平台上进行了机器人的运动学仿真和协调运动研究,验证了该仿真平台的有效性和机器人系统体系结构的合理性。

具有环境自适应能力的多机器人编队系统研究

对多机器人的体系结构进行了研究 .采用时空表和时间控制器相结合的方法 ,解决多机器人间的协调协作问题 .针对编队问题的具体特性 ,提出了基于环境的记忆学习方法 ,使多机器人编队系统具有较强的环境自适应能力 .最后 ,通过仿真实验实现了整个多机器人系统 ,进一步验证了各个算法的可行性和有效性 .