基于K路径算法的多无人机协同航迹规划

对于满足无人机团队中各机同时到达目标这样一个特定的协同要求,首先采用K路径算法实现了无人机的多航迹规划,然后采用速度控制和K路径算法相结合的办法实现了各无人机之间的时间协同.对整个协同航迹规划问题,采用一种分散式求解方法,把高维优化问题分解成低维、计算量小、通讯数据少的问题.     

改进量子遗传算法在无人机航迹规划中的应用

研究无人机航迹规划优化问题,有效地规避威胁,可提高无人机的生存能力.但传统量子遗传算法在航迹规划方面局部寻优精度较低、稳定性差.为解决上述问题,提出改进量子遗传算法的无人机航迹规划方法.首先上述算法采用一维编码表示航迹,并对影响有效规避威胁的适应度构造代价模型和惩罚策略;针对量子遗传算法初始种群的单一性,引入关于概率划分的小生境协同进化策略,并对各种群采用动态量子旋转角,并借鉴狼群分配原则对种群进行更新,提高收敛速度;利用精英选择运算,创建精华种群,保留父代中最佳个体.仿真结果表明,上述算法的无人机航迹规划效率高,稳定性好,能够获得平滑的低代价航迹,是一种有效可行的航迹规划算法,且具有一定的推广意义.     

针对动态目标的多无人机协同组合差分进化搜索方法

针对多无人机动态目标协同搜索问题,提出一种组合差分进化无人机协同搜索航迹规划方法.建立动态目标协同搜索环境信息图模型及无人机运动模型.基于改进差分蝙蝠算法和自适应差分进化算法,设计基于种群数量自适应分配的组合框架,将差分进化算法中的变异、交叉和选择机制引入蝙蝠算法,构建组合差分进化算法的协同搜索算法,并对无人机动态目标协同搜索的航迹进行优化.针对待搜索目标轨迹随机多变且具有规避侦察特性的现实场景,建立可回访数字信息图和自适应目标搜索增益函数,从而提高无人机对动态目标的捕获能力.最后,通过仿真结果验证所提出的无人机动态目标协同搜索算法的有效性.     

基于集成约束无人机两步制航迹规划方法

无人机航迹规划是一个富含地形威胁、雷达威胁和自身可飞性等多约束的优化问题.采用两步制的规划框架,提出一种基于集成约束的无人机航迹规划方法.规划第1阶段采用基于多种群策略的差分进化优化方法,规划第2阶段采用海洋捕食者算法的Lévy运动优化;集成约束机制在搜索过程中动态更新约束策略来补偿可行解数量骤减,抑制搜索停滞.与典型算法和约束处理策略进行对比,实验结果表明,所提出无人机航迹规划方法收敛性好、稳定性强,能够有效地求解复杂多约束无人机航迹规划问题.     

多无人机模糊多目标分布式地面目标协同追踪

针对城市环境中多约束条件下多无人机协同追踪地面目标问题,综合考虑具有不同重要性等级的多个优化目标,提出了一种基于分布式预测控制的模糊多目标航迹规划方法.首先,考虑城市环境中建筑物对无人机视线遮挡、无人机和传感器能量消耗等因素,分别采用目标覆盖度、控制输入代价和开关量形式传感器能耗等为目标函数,将多无人机协同追踪航迹规划转化为多目标优化问题;然后,基于分布式预测控制框架,利用每架无人机未来有限时域内的预测状态,构建多无人机之间的避碰约束,并结合最小转弯半径等约束,形成分布式协同航迹规划模型;最后,针对多个优化目标的不同重要性等级要求,利用模糊满意优化思想将目标模糊化,并根据更重要目标具有更重要满意度的原则,将优先等级表示为松弛满意度序,通过在线求解得到有限时域内每架无人机的局部航迹;与传统多目标加权算法仿真结果对比,验证了所提方法的有效性,充分说明了该方法能够获得同时满足目标优化和重要性等级要求的最优航迹.     

基于生物地理学优化的多UCAV协同航迹规划

研究多无人机协同路径规划问题,为了获取从起始点到达目标点,能够避开各种阻碍的最优运动路径,提出了一种基于BBO的多UCAV协同航迹规划方法.通过对地形环境、航迹表示方式进行描述,将生物地理学优化算法运用于多UCAV协同航迹规划,对约束条件及威胁进行分析,建立了UCAV航迹规划模型及多UCAV协同航迹规划模型;对BBO算法适宜度向量编码及迁徙模型进行了分析,设计了相应的优化算子;最后,构建了多UCAV协同航迹规划的求解框架,并结合BBO算法开展了相应的仿真.仿真结果表明,改进方法较好地实现了多UCAV协同航迹规划的优化.     

关于无人机飞行航迹跟踪优化控制研究北大核心CSCD

研究无人机任务规划中的飞行航迹跟踪优化控制。为克服传统航迹规划算法仅使用航迹关键点难以满足无人机执行任务对航迹跟踪的要求,提出了一种用C^2样条算法融合的无人机三维航迹跟踪优化控制方法,解决了不同航段中无人机的可飞性、边界限制、过载限制等约束。首先针对巡航段航迹采用融合算法中的3D样条优化生成具有时效性的光滑航迹曲线。然后针对任务段航迹采用融合算法中的4D样条优化进一步生成能控制航迹关键点速度的航迹曲线,完成整条航迹的跟踪优化。仿真结果表明,关于C^2样条算法融合的无人机三维航迹优化方法能有效地优化出无人机的实际飞行轨迹,有助于无人机的航迹跟踪控制。能够满足任务规划中无人机对航迹跟踪优化控制的高精度要求,为任务执行提供良好航迹条件。     

基于改进约束差分进化算法的动态航迹规划

为解决三维复杂环境下无人机动态航迹规划问题,提出一种基于改进约束差分进化算法的动态航迹规划方法,以满足对实时性及动态搜索精度的要求.首先,根据无人机航迹规划特点将其描述为包括飞行约束及威胁约束在内的约束优化问题,并构造目标代价函数和约束限制函数;其次,将广义反向学习和自适应排序变异操作引入到约束差分进化算法中,以提高算法的多样性、收敛速度和寻优精度;最后,利用自适应权衡模型对各状态下的约束限制进行处理,充分利用“精英”个体信息,实现对目标适应值的合理转换.通过仿真实验以及与3种先进约束差分进化算法比较表明:所提方法能够有效实现静态及动态威胁回避,规划出安全适航的飞行路径,实现地形跟随;相较于其他3种算法,所提方法具有寻优性能好、鲁棒性强、收敛速度快和可靠性高等优势.     

双机协同交叉定位的三维航迹规划

面向双机协同交叉定位任务,以提高测向定位精度为目的,解决无人机的航迹规划问题。通过分析双机交叉定位的圆概率误差和无人机的动力学约束,建立双机交叉定位的三维航迹规划模型,引入带约束条件的粒子群优化算法,动态规划无人机的航迹,以持续提高测向定位精度,实现无人机的自动化控制。仿真结果表明:粒子群优化算法能有效规划出无人机的航迹,持续提高测向定位精度,算法时效性高,有一定的实际应用价值。     

基于协同进化的混合变量多目标粒子群优化算法求解无人机协同多任务分配问题

无人机多机协同控制系统近年来已被广泛地应用在军事打击、海洋监测、陆地航拍和灾情探测等领域.针对无人机协同多任务分配问题,为了更加准确地描述无人机协同多任务分配场景,本文考虑实际应用场景下的多种复杂约束,并以无人机飞行总航程最少和任务完成时间最短为优化目标,构建了混合变量多约束的无人机协同多任务分配问题模型M-CMTAP.为了高效求解上述模型,本文提出一种基于协同进化的混合变量多目标粒子群优化算法C-MOPSO.C-MOPSO采用基于任务分配和路径规划的编码方法表示无人机的任务分配结果和路径规划结果及基于约束处理的可行解初始化方法生成可行粒子;同时利用基于结构学习的重组策略对粒子进行更新以提高种群的多样性和收敛性;并引入协同进化策略在两个子种群之间进行合作进化以提高算法的搜索效率.根据无人机和目标的分布状态设计4个代表性的测试实例并验证算法性能,实验结果表明,与其他采用协同进化策略的算法相比,所提算法在解的收敛性和解集多样性上均具有显著的性能优势.     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

Call for Papers The 6^th International Conference on Grid and Cooperative Computing

Recent years have seen rapid advances in various grid-related technologies, middleware, and applications. The GCC conference has become one of the largest scientific events worldwide in grid and cooperative computing. The 6th international conference on grid and cooperative computing (GCC2007) Sponsored by China Computer Federation (CCF),Institute of Computing Technology, Chinese Academy of Sciences (ICT) and Xinjiang University ,and in Cooperation with IEEE Computer Soceity ,is to be held from August 16 to 18, 2007 in Urumchi, Xinjiang, China.     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.     

A pragmatic multi-method investigation of discrepant technological events: Coping,attributions, and ‘accidental’ learning

Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice.     

The Distributed Time-Triggered Simulation Scheme: Core Principles and Supporting Execution Engine

Distributed real-time simulation is a young technology field but its practice is under increasing demands. In recent years the author and his collaborators have been establishing a new approach called the distributed time-triggered simulation (DTS) scheme which is conceptually simple and easy to use but widely applicable. The concept was initiated in the course of developing a new-generation object-oriented real-time programming scheme called the time-triggered message-triggered object (TMO) programming scheme. Some fundamental issues inherent in distributed real-time simulation that were learned during recent experimental studies are discussed along with some approaches for resolving the issues. An execution engine developed to support both the TMOs engaged in control computation and the TMOs engaged in DTS is also discussed along with its possible extensions that will enable significantly larger-scale DTSs.     

Software-Konfigurationsmanagement in großen Softwareprojekten

Zusammenfassung Mit zunehmender Größe der Softwaresysteme verschärfen sich die für die Software-Herstellung typischen Probleme: Beherrschen großer Objektmengen, Erhalten der Systemkonsistenz, Kontrolle der ständigen Änderungseinflüsse und Gewährleisten einer langen Lebensdauer. Die Disziplin Konfigurationsmanagement bildet den methodischen Ansatz, diese Probleme besser zu beherrschen. Software-Konfigurationsmanagement faßt die Herstellung von Softwaresystemen als eine Abfolge von kontrollierten Änderungen an gesicherten Zwischen- und Endergebnissen auf. Dargestellt werden die Objekte und Funktionen des Software-Konfigurationsmanagements sowie die hierfür in großen Software-Projekten benötigten Methoden, Instanzen und Hilfsmittel.     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and     

Editorial:Brain-machine interface(BMI) and cyborg intelligence

正Brain-machine interfaces(BMIs)aim at building a direct communication pathway between the brain and an external device,and represent an area of research where significant progress has been made during the past decade.Based on BMIs,mind information can be read out by neural signals to control     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate     

SCIENCE CHINA Information Sciences SUBJECT INDEX TO VOLUME 57(2014)

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