一个面向异构多UUV协作任务的分层式控制系统

针对异构多UUV协作任务,提出了基于多智能体系统的分层式体系结构(MAHA).在个体层面,将UUV智能体的思维状态分为社会心智和个体心智两个层次分别实现,更加符合人类社会协作模式;在群体层面,提出了复杂海洋环境下UUV群体结构的评价准则,并据此将MAHA与现有结构进行了对比分析.此外,利用面向对象的Petri网理论建立了系统的协作模型,有效降低了系统建模的复杂性.最后,水下多目标搜索使命的实例研究表明,MAHA能够保证异构UUV之间进行有效的协作.

制造系统控制结构现状和发展——从集中结构到动态结构

系统的决策控制活动依赖于系统内部的控制结构，制造系统的控制结构是先进制造与自动化领域的重要研究课题。制造系统的控制结构与计算机技术、生产设备自动化水平及制造模式等因素有关。早期的制造系统采用集中控制结构，而柔性制造系统和计算机集成制造系统多采用递阶控制结构。目前制造业已进入一个新时代，传统生产模式和企业结构无法适应不可预测的激烈的环境变化。因此，未来制造系统需要具备快速变化能力的动态控制结构

大型过程工业自动化全过程体系结构

本文首先论述了体系结构对大型自动化系统开发的重要意义，接着从生命周期的观点、递阶控制的观点、自控系统组成三要素的观点对体系结构进行了竖向、纵向、横向的分析。并讨论了各类参考模型对支持平台的要求，最后提出了大型过程工业自动化全过程体系结构，该体系结构对“八·五”攻关课题“大型过程工业综合自动化总体技术”具有指导作用。

A Scheduling Algorithm for Flexible Manufacturing Cell

In this paper, a new scheduling algorithm for the flexible manufacturing cell is presented, which is a discrete time control method with fixed length control period combining with event interruption. At the flow control level we determine simultaneously the production mix and the proportion of parts to be processed through each route. The simulation results for a hypothetical manufacturing cell are presented.

柔性制造单元的智能调度系统

本文基于递阶控制原理提出了柔性制造单元的一种新的计划与调度方法,并综合采用了理论分析、专家系统技术和仿真技术,建立了一个智能调度系统原型.另外,在制造单元调度问题的描述上采用了状态方程形式,从系统的观点来研究调度问题.并在此基础上建立了仿真模块,对单元的加工过程进行了仿真实验.

智能机器人基于作业子空间划分的自学习自适应控制方法

现有的机器人自适应控制基本上都是在建立机器人线性化的动力学模型的基础上,采用某种显式或隐式参数辨识的方法,在线地修正控制作用.本文针对机器人运动和动力学参数变化的固有特点,提出一种完全不同的自学习自适应方法.这种方法基于智能机器人分级系统中的两级结构,并且在空间域里而不是在时间域里处理机器人参数的变化.把机器人的作业空间划分成子空间,其中包括重力载荷的作用,每个子空间对应一组控制器.规划的轨迹映射到作业空间形成子空间序列.用自学习方法选择与这个序列对应的最佳控制器序列.该方法算法简单,计算量小.避开了通常的自适应方法遇到的一系列困难问题.

Ordered Zinc Antimonate Nanoisland Attachment and Morphology Control of ZnO Nanobelts by Sb Doping

Hierarchical heterostructures of zinc antimonate nanoislands on ZnO nanobelts were prepared by simple annealing of the polymeric precursor. Sb can promote the growth of ZnO nanobelts along the [552] direction because of the segregation of Sb dopants on the +(001) and (110) surfaces of ZnO nanobelts. Furthermore, the ordered nanoislands of toothlike ZnSb2O6 along the [001](ZnO) direction and rodlike Zn7Sb2O12 along the [110](ZnO) direction can be formed because of the match relation of the lattice and polar charges between ZnO and zinc antimonate. The incorporation of Sb in a ZnO lattice induces composition fluctuation, and the growth of zinc antimonate nanoislands on nanobelt sides induces interface fluctuation, resulting in dominance of the bound exciton transition in the room temperature near-band-edge (NBE) emission at relatively low excitation intensity. At high excitation intensity, however, Auger recombination makes photogenerated electrons release phonon and relax from the conduction band to the trap states, causing the NBE emission to gradually saturate and redshift with increasing excitation intensity. The green emission more reasonably originates from the recombination of electrons in shallow traps with doubly charged V-O** oxygen vacancies. Because a V-O** center can trap a photoactivated electron and change to a singly charged oxygen vacancy V-O* state, its emission intensity exhibits a maximum with increasing excitation intensity.

Facile Synthesis and Assemblies of Flowerlike SnS2 and In3+-Doped SnS2: Hierarchical Structures and Their Enhanced Photocatalytic Property

Novel flowerlike SnS2 and In3+-doped SnS2 hierarchical structures have been successfully synthesized by a simple hydrothermal route using biomolecular L-Cysteine-assisted methods. The L-cysteine plays an important role both as assistant and as sulfur source. Experiments with various parameters indicate that the pH values have a strong effect on the morphology of the assembly. Based on the experiments, a growth mechanical process was proposed. The synthetic samples were characterized by XRD, SEM, TEM (HRTEM), BET measurement, TGA, and XPS in detail.

SrF2 hierarchical flowerlike structures: Solvothermal synthesis, formation mechanism, and optical properties

We present a solvothermal route to the synthesis of SrF2 hierarchical flowerlike structures based on thermal decomposition of single source precursor (SSP) of strontium trifluoroacetate in benzylamine solvent. These flowerlike superstructures are actually composed of numerous aggregated nanoplates, and the growth process involves the initial formation of spherical nanoparticles and subsequent transformation into nanoplates. which aggregated together to form microdisks and finally flowerlike superstructures. The results demonstrate the important role of benzylamine in the formation of well-defined SrF2 superstructures, not only providing size and shape control to form nanoplates but also contributing to the self-assembly behavior of nanoplates to build into flower-like superstructures. Additionally, the photoluminescence properties of the obtained SrF2 superstructures are studied.

Low-density polyethylene superhydrophobic surface by control of its crystallization behavior

A simple and inexpensive method for forming a low-density polyethylene (LDPE) superhydrophobic surface by controlling the crystallization behavior of LDPE by adjusting the crystallization time and nucleation rate has been proposed. The resulting porous surface, with hierarchical micro- and nanostructures on the beautiful floral designs, has a water contact angle of 173.0degrees +/- 2.5degrees.

Population genetic structure of crimson snapper Lutjanus erythropterus in East Asia, revealed by analysis of the mitochondrial control region

The population genetic structure of the crimson snapper Lutjanus erythropterus in East Asia was examined with a 427-bp hypervariable portion of the mtDNA control region. A total of 262 samples were collected and 75 haplotypes were obtained. Neutrality tests (Tajima's and Fu's) suggested that Lutjanus erythropterus in East Asia had experienced a bottleneck followed by population expansion since the late Pleistocene. Despite the low phylogeographic structures in mtDNA haplotypes, a hierarchical examination of populations in 11 localities from four geographical regions using analysis of molecular variance (AMOVA) indicated significant genetic differentiation among regions (Phi(CT) = 0.08564, p < 0.01). Limited gene flow between the eastern region (including a locality in the western Pacific Ocean and two localities in the East Sea) and three geographic regions of the South China Sea largely contributed to the genetic subdivision. However, comparisons among three geographic regions of the South China Sea showed little to no genetic difference. Populations of Lutjanus erythropterus in East Asia are inferred to be divided into two major groups: an eastern group, including populations of the western Pacific Ocean and the East Sea, and a South China Sea group, consisting of populations from northern Malaysia to South China. The results suggest that fishery management should reflect the genetic differentiation and diversity in East Asia. (c) 2006 International Council for the Exploration of the Sea. Published by Elsevier Ltd. All rights reserved.