基于有限元技术的工业机器人本体刚度优化设计

采用有限元分析技术,对工业机器人整机进行有限元建模;基于有限元模型对整机和各零部件进行刚度贡献度分析,将分析结果和现有评价标准进行对比,识别待优化零部件;对待优化零部件采用结构拓扑优化技术进行优化,最终得出刚度合理的零部件及整机设计方案。通过对比优化前后的整机刚度综合系数和质量参数,可知本文所述方法能够在机器人设计阶段有效优化工业机器人的整机刚度和整体质量,使得机器人刚度设计更为合理。     

基于遗传算法的三平动3-PRRRR并联机器人正解位形的研究与仿真

由于并联机器人构型的特点,在其运动学分析中,正解分析较为复杂,也是在研究并联机器人运动学过程中的一个难点.本文采用遗传算法,将并联机器人的运动学正解问题转化为优化问题.利用MATLAB遗传算法工具箱对三平动3-PRRRR并联机器人的正解问题进行求解,得到优化解,并用反解结果与正解结果进行互相印证,证明该方法对于并联机器人正解问题具有较高的实用性.     

基于Ansys Workbench的机器人底座结构的有限元分析

应用Solid Works软件以某船厂车间机器人底座结构为例,建立三维钢架结构模型。将建好的三维钢架模型直接无误差导入ANSYS Workbench软件,设定适当单元格大小和选择单元格类型对有限元模型网格划分,为机器人底座结构优化改进提供有限元模型。充分运用ANSYS Workbench中的静态结构模块分析机器人底座模型的静强度、静刚度。根据有限元计算得到机器人底座结构模型等效应力和变形分布云图,制定机器人底座结构优化改进方案。通过对提出的A、B两种优化改进方案的有限元结果进行对比分析,优化改进后的底座钢架结构机械性能和安全系数都得到明显提高,同时,达到了最初的设计要求。     

基于双层自适应遗传算法的机器人参数辨识

激励轨迹的选取和优化是机器人动力学参数辨识的重要基础。为了提高机器人动力学参数的辨识精度，本文以SCARA机器人为研究对象，设计了基于双层自适应遗传算法的机器人激励轨迹优化方案。运用Newton-Euler法建立了机器人的动力学模型，并对机器人的动力学模型进行线性分离，得到了机器人的最小惯性参数集和对应的观测矩阵。分析机器人的参数辨识方程，确定了观测矩阵条件数最小的优化目标。针对传统遗传算法进行改进，提出了双层自适应机制，提升了算法的全局搜索能力和搜索效率。最后利用MATLAB和ADAMS进行联合仿真实验，使用递推最小二乘法计算机器人的最小惯性参数集。实验结果表明，使用改进的双层自适应遗传算法得到的激励轨迹可以保证机器人动力学参数的辨识精度。     

一种武术擂台赛机器人的漫游策略分析

多次测试实践表明,擂台机器人的漫游直接影响到后期的机器人对抗.通过对机器人漫游的测试和分析,提出漫游优化策略,为机器人对抗设计奠定基础.     

空间关节机器人轨迹规划

提出了一种简捷的空间关节机器人运动轨迹的优化方法。对求解机器人运动学逆问题较为有效。通过实例分析，它所得运动参数不但满足作业要求，而且使机器人以最佳状况进行作业。     

基于APO的群机器人目标搜索仿真系统设计

针对群机器人目标搜索问题,采用拟态物理学优化算法作为群机器人的建模工具,参考优化个体间的引斥力规则建立机器人间的作用力规则,参考优化个体的质量函数构造有关机器人感知强度的虚拟质量函数,建立群机器人目标搜索模型。根据模型参数较多,要求查看群机器人搜索过程的特点,开发了基于拟态物理学优化算法的群机器人目标搜索仿真系统,实现了参数的灵活定制,动态演示群机器人搜索过程以及生成实验结果报表等功能。     

清洗机器人样机操作臂结构参数优化

高层建筑清洗机器人是应用于高层建筑外墙清洗作业的一种特殊作业机器人。本文以样机为原型，通过理论分析与计算机仿真，对其进行了旨在改善偏重力矩的结构优化。不但使结构更趋于合理化，而且保证了操作性能良好。本文对该机器人的产业化研究有直接的指导作用，而且为其它机器人的优化提供了有益的借鉴。     

施釉机器人机构参数优化设计

针对一种手把手示教的施釉机器人进行机构参数优化设计。分析了在给定工作空间下的设计变量、优化目标和约束条件，建立了约束方程。根据作业对象和要求，利用Matlab进行编程，实现了机器人机构参数优化。     

计入多个闭链影响的四自由度机器人动力学优化

文章以动力学性能指标为优化目标,对含多个局部闭链的四自由度码垛机器人结构设计中的尺寸参数优化设计方法进行了讨论;充分考虑多个局部闭链间的相互影响,建立了码垛机器人的刚体动力学模型,对模型的计算精度进行了验证分析;在此基础上,针对机器人典型的运动轨迹下的动力学性能优化设计方法进行了探讨,以机器人各驱动关节的峰值扭矩和机器人总能耗最小为动力学优化目标;优化过程中,计入杆件质量和质心位置的影响,并利用平方和加权法将多目标优化问题转变为单目标优化问题。算例结果表明,优化后各项动力学性能指标得到明显改善,腰部、大臂和小臂的驱动峰值扭矩降幅分别为8.35%、16.23%和10.45%,机器人总能耗降幅为9.78%,验证了该优化方法的有效性。     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.