自治水下机器人的自主启发式生物启发神经网络路径规划算法

针对复杂海流环境下自治水下机器人(autonomous underwater vehicle, AUV)的路径规划问题,本文在栅格地图的基础上给出了一种基于离散的生物启发神经网络(Glasius bio-inspired neural networks, GBNN)模型的新型自主启发式路径规划和安全避障算法,并考虑海流对路径规划的影响.首先建立GBNN模型,利用此模型表示AUV的工作环境,神经网络中的每一个神经元与栅格地图中的位置单元一一对应;其次,根据神经网络中神经元的活性输出值分布情况并结合方向信度算法实现自主规划AUV的运动路径;最后根据矢量合成算法确定AUV实际的航行方向.障碍物环境和海流环境下仿真实验结果表明了生物启发模型在AUV水下环境中路径规划的有效性.     

海流环境下多AUV多目标生物启发任务分配与路径规划算法

针对多障碍物海流环境下多自治水下机器人(AUV)目标任务分配与路径规划问题, 本文在栅格地图构建的 基础上给出了一种基于生物启发神经网络(BINN)模型的新型自主任务分配与路径规划算法, 并考虑海流对路径规 划的影响. 首先建立BINN模型, 利用此模型表示AUV的工作环境, 神经网络中的每一个神经元与栅格地图中的位 置单元一一对应; 接着, 比较每个目标物在BINN地图中所有AUV的活性值, 并选取活性值最大的AUV作为它的获 胜AUV, 实现多AUV任务分配; 最后, 考虑常值海流影响, 根据矢量合成算法确定AUV实际的航行方向, 实现AUV路 径规划与安全避障. 海流环境下仿真实验结果表明了生物启发模型在多AUV水下任务分配与路径规划中的有效性.     

基于前视声纳信息的AUV局部路径规划研究

针对水下环境的不确定性,建立了前视声纳的视域模型。主要采用强化学习的方法对自治水下机器人(AUV)进行控制和决策,综合Q学习算法、BP神经网络法、人工势场法对AUV进行局部路径规划。在AUV与环境的试错交互中,借助于来自成功与失败经验的奖励和惩罚值,不断改进水下机器人的自治能力。并设计了AUV局部路径规划器,实现AUV在不确定环境下的避障任务。半实物仿真证明了算法的可行性与可靠性。     

不确定海流环境下水下机器人最优时间路径规划

为解决海流预测不精确条件下,现有基于确定性海流路径规划算法鲁棒性差和规划的路径有可能为不可行路径的问题,本文提出一种基于区间优化的水下机器人(AUV)最优时间路径规划算法.该算法采用双层架构,外层用蚁群系统算法(ACS)寻找由起点至终点的候选路径;内层以区间海流为环境模型,计算候选路径航行时间上下限,并分别通过区间序关系和基于可靠性的区间可能度模型将航行时间区间转换为确定性评价函数,并将评价函数值作为候选路径适应度值返回到外层算法.仿真结果表明,相对于确定海流场路径规划方案,提出的方案增强了路径规划器的鲁棒性并解决了结果路径不可行问题.     

基于人工势场法的AUV避障算法研究综述

简述了人工势场法的概念,分析了人工势场法的引力和斥力势场模型,指出了人工势场法在应用中存在的水下复杂环境问题、目标不可达问题、局部极小值问题;从考虑复杂障碍物因素和海流因素两方面阐述了水下复杂环境问题的研究现状,从对势场函数进行重新定义或对斥力势场函数进行修正两方面阐述了目标不可达问题的研究现状,从设置虚拟引导点等方面阐述了局部极小值问题的研究现状,并且阐述了几种组合避障算法的研究现状;从构造更完善的势场函数模型、考虑复杂海流因素影响、算法融合以及在算法中加入路径评价机制等方面对人工势场法未来的发展方向进行了展望。     

自治水下机器人避碰算法及其仿真研究

为了提高水下机器人(AUV)在复杂海洋环境下的自适应性,文章对传统的避碰方法进行了改进.对AUV的禁入区和潜在碰撞区进行了安全性分析.建立了前视声纳模型以及三维水下规划空间模型.提出了基于强化学习、BP神经网络及人工势场相结合的避碰算法.在AUV与环境的试错交互中,借助于来自成功和失败经验的奖励和惩罚值,不断改进水下机器人的自治能力.设计了AUV深度行为模糊协调器, 对潜深行为和距底高度行为进行协调融合.开发了AUV运动规划与仿真的半实物软件系统,仿真试验证明了算法的合理性与可行性.研究对于提高AUV的自主性和安全性具有重要的应用价值.     

基于传感器信息的AUV局部避碰研究

采用势场法对自主水下机器人(AUV)进行局部避碰规划.在建立前视声呐视域模型和人工势场模型的基础上,对AUV进行决策控制,通过梯度逼近法对目标进行搜索,快速规划出一条无碰撞的路径.在障碍物检测上,设计了监测模块,实时检测障碍的类型,指导AUV进行运动轨迹解算.在AUV深度控制上,设计了AUV深度行为模糊协调器,对最小潜深、最小距底高度进行协调,实时解算AUV深度行为.开发了AUV运动规划与仿真的半实物软件系统,仿真实验证明了算法的合理性与可行性.研究对于提高AUV的自主性和安全性具有重要的应用价值.     

一种时变洋流场下AUV最优能耗路径规划方法

在时变洋流场环境下,洋流矢量增加了时间维度,在时间角度上可进一步利用洋流以节约自主水下机器人(AUV)能量消耗.此外,在该环境中无后效性不再成立,基于经典贪婪策略的路径规划算法不再适用.鉴于此,结合路径参数选择和双层规划算法,提出一种适用于时变洋流场环境的能耗最优路径规划算法.出发时间和AUV推进速度均可以在时间维度上等待有利洋流,且推进速度与其能量消耗直接相关,因此,引入出发时间和推进速度作为路径参数.在此基础上,针对无后效性不成立问题,使用双层规划作为路径规划算法,分析该算法在时变洋流场环境下的适用性.算法将路径规划任务分为路径规划与路径优化两部分,路径规划部分采用蚁群系统算法构建通道,路径优化部分由量子粒子群算法对路径参数进一步优化,在保证全局最优的同时能够解决传统基于栅格的路径规划算法中机器人运动方向受限的问题.最后以Kongsberg/Hydroid REMUS 600s型水下机器人为模型,对所提出的路径规划算法进行仿真验证.     

改进粒子群在水下机器人路径规划中的应用

在海洋环境中水下机器人路径规划具有规划范围广阔、障碍物相对稀疏、海流的影响不可避免的特点。应用粒子群优化(PSO)算法实现水下机器人在复杂海洋环境中的路径规划,并从参数控制策略及拓扑模型方面进行改进,得到收敛精度更好的改进粒子群优化算法。设计了综合路径长度、海流和转向费用的适应度函数,使算法很好地适应海流的变化,很大程度减小了海流对水下机器人能量消耗和控制的不利影响。经仿真实验验证了算法的有效性,并能够很好地满足在复杂海况环境水下机器人路径规划的要求。     

改进的势场蚁群算法的移动机器人路径规划

针对蚁群算法路径规划初期信息素浓度差异较小,正反馈作用不明显,路径搜索存在着盲目性、收敛速度相对较慢、易陷入局部最优等情况,人工势场算法的势场力可引导机器人快速朝目标位置前进,提出势场蚁群算法,通过栅格法对机器人的工作环境进行建模,利用人工势场中的势场力、势场力启发信息影响系数及蚁群算法中机器人与目标位置的距离构造综合启发信息,并利用蚁群算法的搜索机制在未知环境中寻找一条最优路径。大量的仿真实验表明势场蚁群算法路径规划能找到更优路径和收敛速度更快。     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

基于QTE的蒙古文显示机制研究与实现

蒙古语言是中国蒙古族使用的通用语言,由于蒙古文区别于其他文字的书写方式和其自身变形机制等特点,在很多通用的文字处理引擎中都不被支持。在嵌入式产品开发与应用领域中Linux加QTE已经成为流行方式。该文给出了一种在QTE环境上实现基于标准Unicode的蒙古文点阵显示和变形算法, 并自定义了支持蒙古文的QTE组件,扩展了QTE功能,为在Linux加QTE方式的嵌入式体系结构中处理蒙古文提供了一种解决方法。