983 resultados para Path Planning


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The broad acceptance and collective commitment of countries to the tasks involved in the implementation of Agenda 21, Chapter 17, have profound implications vis-à-vis the interplay between coastal zone management (CZM) and national development planning (NDP). It appears that in many countries, CZM has evolved in isolation from the mainstream of national development processes. The paper examines various forms and elements for the effective integration of CZM into NDP.

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This article describes the design of a new type of long-path-length thin-layer cell (LPTLC), which is constructed by inserting two Teflon cell bodies into a standard cuvette. This cuvette holder enables the LPTLC to combine with photometric instrumentation conveniently. Gold, platinum, glassy carbon, and other materials can be used for the working electrode. Since no soluble adhesive material is used, the cell can meet various needs (in situ conventional and derivative W-vis, in situ circular dichroism, etc.) in both aqueous and nonaqueous systems.

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The adsorption of cationic surfactant cetylpyridinium bromide (CPB) on a glassy carbon (GC) electrode surface has been studied by spectroelectrochemistry with a long optical path length thin-layer cell (LOPTLC) for the first time. A fine adsorption isotherm of CPB molecules from an aqueous solution containing 0.10 M KBr has been obtained over the range of (1.00-8.00) x 10(-5) M. From theoretical calculation and experimental data, adsorption of CPB on the GC electrode surface shows four distinct orientations and three large orientation transitions. Compared with the ordinary isotherm, the differential isotherm is more characteristic and would be suitable for the study of orientation transitions of organic compounds. With a theoretical treatment of the adsorption isotherm, four orientations of adsorbed CPB on a GC electrode surface coincide with the Frumkin-Langmuir type. From adsorption parameters the Frumkin-Langmuir equations, the adsorption free energy and, therefore, the equilibrium constants of orientation transitions of the CPB molecule can be obtained.

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In this paper, the electric dichroism of cetylpyridinium bromide (CPB) has been found and studied by spectroelectrochemistry with a long optical path length thin-layer cell (LOPTLC) for the first time. The CPB molecule with a long carbon chain and a polar pyridinium ring is anisotropic in molecular configuration or in polarizability. In the electric field of a thin-layer cell, the CPB molecule reorientates along the direction of the electric field and exhibits electric dichroism, which results in the increase of absorbance of CPB in the UV-vis range. By use of in situ measurement of spectroelectrochemistry, the order parameters of long molecular axis (S = 0.845) and short molecular axis (D = 0.155) and the angle between the long axis direction of the CPB molecule and the direction normal to the electrode surface (theta = 18-degrees 44') have been determined. These data were used to describe the state of arrangement of the molecules in the solution. The reorientation of CPB molecules is the result of the interaction between the anisotropic molecules and electric field. The effects of the concentration of CPB and of the applied electric field on the electric dichroism have been investigated.

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提出了一个对超冗余度机械臂路径规划进行安全性优化的新方法 .采用一般随机路标法得到一个表示机械臂位形空间结构信息的路标 ,计算机械臂在各个位形下与障碍物之间的最小距离 ,并把此信息加到随机路标法所求的路标上 ,从而把路标转化为网格结构 .基于此网络 ,给出了一个对路径进行安全性优化的数学模型 ,利用其对超冗余度机械臂进行路径规划 .仿真结果表明 ,相对于一般随机路标法所建模型规划的路径安全性大大提高

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基于超冗余度机械臂的动力学方程 ,提出了一种超冗余度机械臂同时受速度和力矩约束的时间最优轨迹规划方法 .它首先采用 B样条曲线拟合无碰撞离散路径 ,得到由伪位移参数 s表示的超冗余度机械臂连续、光滑运动路径 ,然后对动力学方程和约束方程进行数学变换 ,得到由 s表示的动力学方程和约束方程 ,最后以 s和伪速度 s· 分别作为动态规划的阶段变量和状态变量 ,对超冗余度机械臂进行时间最优轨迹规划 .仿真结果表明 ,所给出的时间最优轨迹规划算法是正确的 ,所采取的解决方法是可行的

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研究移动机器人在动态环境中的导航与避障问题。为提高规划的实时性,提出了基于规则的规划方法,将多移动障碍环境机器人的运动规划分解为相对简单的单移动障碍运动规划,利用最优控制来实现单障碍的最优避障,并用智能搜索方法解决了移动机器人在多移动障碍环境中的实时运动规划问题。仿真实例表明了该方法的有效性。

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研究了不确定性环境下移动机器人躲避运动轨迹未知的移动障碍物的一种新方法.通过实时最小均方误差估计算法预测每个障碍物的位置及运动轨迹,并利用模式识别中最小均方误差分类器的修正模型计算出机器人的局部避障路径,再运用船舶导航中使用的操纵盘技术来确定每个导航周期中移动机器人的速.度仿真结果表明了该方法的可行性

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本文提出的面向任务的机器人语言是为移动机器人提供的一种编程工具。利用环境描述语言和其他灵活的人机对话方式建立环境模型;根据各种不同的性能指标,规划出最佳路径;根据安全等因素自动规划出最佳路径上的行走参数;对来自传感器的信息进行处理,以确定机器人实际位置及障碍情况;引导机器人沿规划好的路径行走,纠正偏差或重新选择避障路径。

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本文简要地介绍了数控自动编程专家系统.其中包括:专家系统知识表示的形式;分层次的黑板结构;前向推理求解策略和相应的解释功能;系统针对不同类型的曲线组合,采用不同的独立的知识源(KS)进行处理.由于在知识的处理上采用编码技术,在前向推理求解策略中使用启发信息和“剪技”技术,提高了系统的时空效率.系统中的规划程序能自动规划切削路径.输出供数控车床使用的 NC 代码,并可在显示屏上进行图形显示和切削仿真.目前原型系统已经在 IBM-PC 和 Sun3/60计算机上利用FORTRAN 语言实现.

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基于鞍钢新轧集团股份有限公司冷轧薄板厂MES工程的实际情况,介绍了机组排产作业计划过程中的任务分配方法。该方法以机组与生产任务的最佳匹配、机组的负荷平衡为性能指标,采用了实时最小负荷分配规则,科学地解决了冷轧生产线CIMS环境下机组排产作业计划的在线生成问题,实现了生产线上的生产路径优化控制,从而提高了生产质量和设备利用率。

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On the basis of analyzing the principle and realization of geo-steering drilling system, the key technologies and methods in it are systematically studied in this paper. In order to recognize lithology, distinguish stratum and track reservoirs, the techniques of MWD and data process about natural gamma, resistivity, inductive density and porosity are researched. The methods for pre-processing and standardizing MWD data and for converting geological data in directional and horizontal drilling are discussed, consequently the methods of data conversion between MD and TVD and those of formation description and adjacent well contrast are proposed. Researching the method of identifying sub-layer yields the techniques of single well explanation, multi-well evaluation and oil reservoir description. Using the extremum and variance clustering analysis realizes logging phase analysis and stratum subdivision and explanation, which provides a theoretical method and lays a technical basis for tracing oil reservoirs and achieving geo-steering drilling. Researching the technique for exploring the reservoir top with a holdup section provides a planning method of wellpath control scheme to trace oil and gas reservoir dynamically, which solves the problem of how to control well trajectory on condition that the layer’s TVD is uncertain. The control scheme and planning method of well path for meeting the demands of target hitting, soft landing and continuous steering respectively provide the technological guarantee to land safely and drill successfully for horizontal, extended-reach and multi-target wells. The integrative design and control technologies are researched based on geology, reservoir and drilling considering reservoir disclosing ratio as a primary index, and the methods for planning and control optimum wellpath under multi-target restriction, thus which lets the target wellpath lie the favorite position in oil reservoir during the process of geo-steering drilling. The BHA (bottomhole assembly) mechanical model is discussed using the finite element method, and the BHA design methods are given on the basis of mechanical analyses according to the shape of well trajectory and the characteristics of BHA’s structure and deformation. The methods for predicting the deflection rate of bent housing motors and designing their assemblies are proposed based on the principle of minimum potential energy, which can clearly show the relation between the BHA’s structure parameters and deflection rate, especially the key factors’ effect to the deflection rate. Moreover, the interaction model between bit and formation is discussed through the process of equivalent formation and equivalent bit considering the formation anisotropy and bit anisotropy on the basis of analyzing the influence factors of well trajectory. Accordingly, the inherence relationship among well trajectory, formation, bit and drilling direction is revealed, which lays the theory basis and technique for predicting and controlling well trajectory.

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Population data which collected and saved according to administrative region is a kind of statistical data. As a traditional method of spatial data expression, average distribution in every administrative region brings population data on a low spatial and temporal precision. Now, an accurate population data with high spatial resolution is becoming more and more important in regional planning, environment protection, policy making and rural-urban development. Spatial distribution of population data is becoming more important in GIS study area. In this article, the author reviewed the progress of research on spatial distribution of population. Under the support of GIS, correlative geographical theories and Grid data model, Remote Sensing data, terrain data, traffic data, river data, resident data, and social economic statistic were applied to calculate the spatial distribution of population in Fujian province, which includes following parts: (1) Simulating of boundary at township level. Based on access cost index, land use data, traffic data, river data, DEM, and correlative social economic statistic data, the access cost surface in study area was constructed. Supported by the lowest cost path query and weighted Voronoi diagram, DVT model (Demarcation of Villages and Towns) was established to simulate the boundary at township level in Fujian province. (2) Modeling of population spatial distribution. Based on the knowledge in geography, seven impact factors, such as land use, altitude, slope, residential area, railway, road, and river were chosen as the parameters in this study. Under the support of GIS, the relations of population distribution to these impact factors were analyzed quantificationally, and the coefficients of population density on pixel scale were calculated. Last, the model of population spatial distribution at township level was established through multiplicative fusion of population density coefficients and simulated boundary of towns. (3) Error test and analysis of population spatial distribution base on modeling. The author not only analyzed the numerical character of modeling error, but also its spatial distribution. The reasons of error were discussed.

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This paper presents a simple, sound, complete, and systematic algorithm for domain independent STRIPS planning. Simplicity is achieved by starting with a ground procedure and then applying a general and independently verifiable, lifting transformation. Previous planners have been designed directly as lifted procedures. Our ground procedure is a ground version of Tate's NONLIN procedure. In Tate's procedure one is not required to determine whether a prerequisite of a step in an unfinished plan is guarnateed to hold in all linearizations. This allows Tate"s procedure to avoid the use of Chapman"s modal truth criterion. Systematicity is the property that the same plan, or partial plan, is never examined more than once. Systematicity is achieved through a simple modification of Tate's procedure.