一种分阶段优化的排料算法

提出一种基于分阶段优化的排料算法.在算法的第一阶段,在排料前先估算本阶段用到的原板材尺寸和数量,将权重因子超过阅值的待排件均匀分布在其上.在排料过程中再根据待排件权重因子和组合因子动态调整空闲区域的排料布局,从而可大幅度降低排料算法复杂度,提高板材利用率.在第二阶段,将剩余待排件合理排放在原板材上,在排料即将结束时,可根据相邻因子确定排料布局以减少废料碎片.生产实践表明,这样研制出的排料系统利用率高、布局合理,能满足工业上的一刀切要求.     

排料算法优化

用计算机进行计算、优化排料是剪、冲裁等材料加工过程中非常值得关注的问题。对贵金属、特种材料和高档装饰材料等,提高它们的利用率具有明显的经济效益。 排料优化问题依照算法和材料的不同可分为矩形板排料和连续带排料两大类。在剪裁加工中材料大多为矩形板材,常采用矩形板材优化排料算法。有时还要把冲剪顺序、冲剪方式等作为附加条件考虑在优化过程中。这类优化过程中按工件形状又分为两类：复杂工件排料、矩形工件排料。矩形板材排料过程中工件种类多,尺寸各异。 在连续冲裁加工中材料大多为宽度给定的连续带,工件种类单一。按照…     

基于CASE推理的排样算法

优化排料的目的是根据给定待排样品对板材进行最优切割使得板材的利用率尽可能的高。提出了一种基于case推理的优化排样算法,基本思想是对每块板材的布局都进行case推理,选取CASE中的最佳布局,若没有相应的Case,则调用启发式算法搜索。算法不但避免了组合爆炸,加快了排料速度,而且具有满意的材料利用率。目前算法已集成了作者研制的《布局之星》切割系统,实际应用表明算法是成功的。     

基于PSO-SA算法的优化排料研究

现今用于家具制造的木材及板材的使用量大幅度增加。板材用料的合理利用与木材资源的浪费问题,越来越受到国家及社会的高度关注。在家具生产中,板式材料的合理剪裁成为现在的研究热点。根据现代社会产生的木材合理利用为研究点采用PSO-SA优化算法,对板式办公家具木质材料的优化排料方式进行建模。PSO-SA将PSO算法的优点与SA算法的优点运用在算法的实现中,并将两种算法进行有效结合,使之达到最良好的优化效果。尽量避免和减少其余料的产生和浪费,达到利用率最高的目的。同时提高辅助材料的价值和可用性。     

求解板材排料问题的新方法

§１．引言 板材排料问题是家具、包装、地毯等行业常见的一个问题．它是指将一批不同种类的待排矩形件全部排放在给定的板材上,使排料所用的板材数量尽可能地少,即板材的利用率尽可能地高．实质上是一个组合优化的二维布局问题,从计算复杂性来看,是一个ＮＰ完全问题,但至今还没有找到解决该问题的有效多项式时间算法．寻求其近似最优解的近似算法是目前解决该问题的途径之一． 国内外已有不少学者在布局问题方面作了一些研究．如有用模拟退火算法解决大规模排料问题,但其解过分依赖于模拟退火算法冷却进度表的参数的选取,而且该算法…     

矩形件优化排样的混合启发式方法

提出一种启发式递归与遗传算法相结合的混合启发式算法求解矩形件优化排样问题。首先给出一种启发式递归算法,利用该算法逐个从待排矩形件中生成局部利用率高的条料,直到所有待排矩形件均生成条料;利用遗传算法全局搜索能力强的特点,对这些条料序进行搜索重组,使其所用的板材数最少;最后再次利用遗传算法,对条料生成之前的矩形件种类序进行全局最优搜索,使总的板材利用率达到了最大。对两个典型实际算例进行计算,并与相关文献比较,结果表明了该算法的有效性。     

一种基于四叉树结构的排料算法

提出了一种利用四叉树结构来描述矩形物体排料过程的算法。为了确保排料布局的合理性，满足工业上的一刀切要求，需采用组合规则和邻接规则来合成矩形块，这样做还可减少废料碎片、降低算法复杂度、提高板材利用率。     

具有条带约束和简化排样方式功能的排样系统分析

在板材分割中应用优化排样算法,能够提高材料利用率,从而降低生产成本。本文对基本的动态规划算法加以改造,使之能够处理最小和最大条带长度约束,能够生成切割工艺最简单的排样方式。在C＋＋环境下,在已有原型的基础上,开发出同尺寸矩形毛坯排样系统UR。利用这个软件,进行了大量的例题测试,得出对生产实践具有指导意义的结论。     

基于人工蜂群算法的疏散运动仿真

针对原始人工蜂群算法在人群疏散仿真中存在的早熟停滞问题,提出一种基于种群划分思想的新型蜂群算法.以种群划分为基础,利用多种群协同进化机制扩展求解的多样性,防止算法陷入局部最优.以ACIS/HOOPS为平台搭建3D仿真系统,对改进算法进行人群疏散仿真及对比分析,结果表明,与原始算法相比,该算法在精度和收敛速度上明显提升.与粒子群优化算法相比,该算法能够实现人群疏散的均衡分布,提高应急疏散的效率.     

基于多目标进化算法的手机概念设计优化

针对手机设计领域应用计算机辅助设计存在的一些问题,以及如何处理相互冲突的多目标间的优化问题,深入地分析了概念设计过程中的创新思维和多目标优化的基本理论.在手机概念设计阶段同时考虑了用户要求.构件设计属性.设计成本和综合评价值等多种因素,将分布估计算法应该于求解手机集成的多目标优化问题,给出了具体的方法和步骤.实验结果表明,该方法可以提高设计的创新性,给设计人员提供有益的借鉴.     

协同模板中几何约束关系的表示与解释

模板设计标记语言TDML是协同模板中描述设计信息的标记语言，主要用于表示设计对象的部件信息、部件属性信息、部件位置装配关系信息、操作和连接信息等。设计对象是由一系列部件按照一定的约束关系装配而成的，所以约束信息是设计对象重要的结构信息。文章分析并总结了设计对象之间的几何约束及装配位置关系，采用TDML语言加以描述和解释，并用三维建模器ACIS实现了设计部件间位置关系的可视化。     

基于Web的三维协同设计模型及其关键技术

为在虚拟环境下进行产品异地实时设计和装配,提出一种基于Web的三维协同设计模型.该模型使用户既可以通过浏览器在客户端的虚拟场景中进行个性化设计,也可以与其他用户进行协同设计.通过详细分析协同设计过程,研究任意形状基本实体的表征、零件扩展属性的描述、基本操作的表示、零件之间装配关系和部件运动仿真属性等的建立.基于ACIS和ECSG的三维造型技术和层次细节模型的生成算法,研发以某产品为对象的原型系统,证实该三维协同设计模型的可行性和先进性.     

基于HOOPS接口技术的3D造型的研究*

ACIS是全球著名的3D造型软件开发平台,介绍了ACIS的新接口技术——HOOPS以及它的组件、功能、特色和应用,展示了一个应用开发实例。     

A layout algorithm for undirected compound graphs

We present an algorithm for the layout of undirected compound graphs, relaxing restrictions of previously known algorithms in regards to topology and geometry. The algorithm is based on the traditional force-directed layout scheme with extensions to handle multi-level nesting, edges between nodes of arbitrary nesting levels, varying node sizes, and other possible application-specific constraints. Experimental results show that the execution time and quality of the produced drawings with respect to commonly accepted layout criteria are quite satisfactory. The algorithm has also been successfully implemented as part of a pathway integration and analysis toolkit named PATIKA, for drawing complicated biological pathways with compartmental constraints and arbitrary nesting relations to represent molecular complexes and various types of pathway abstractions.     

手机产品的差异性对手机在线阅读行为的影响

本文研究的是手机产品的差异性对手机在线阅读行为的影响.通过分析用户的手机在线阅读行为,从“手机观感”,“手机性能”,“网络情况”三大基本影响因素进行探讨分析,通过相关理论研究以及问卷调查的方式得出手机性能、显示舒适度对手机在线阅读行为的影响最大,以及阅读平台的性能、版面设计、附加功能丰富度对其关系都具有一定的调节作用,且调节作用的大小不一.     

Multi-module satellite component assignment and layout optimization

In previous optimization methods for multi-module satellite equipment (component) layout optimization problem, each component was limited to certain module or supporting surface and could only search its position there. Components could not migrate from one module or supporting surface to another. In this case, the layout design of components within satellite module was seriously hindered from further improvement. In this study a component assignment and layout integration optimization algorithm is presented to deal with this problem, which can assign components to each module of satellite dynamically during optimization procedure. The aim of this paper is to expand the solution space of component layout optimization so as to further improve the component layout design. The proposed component assignment and layout integration optimization algorithm is inspired from the idea of stepwise regression in multiple regression analysis, which allows independent variables to enter or leave regression equation freely. In the proposed algorithm components enter the satellite module one by one in descending order of the product of mass and height. For all supporting surfaces within satellite module, each component will try all of them through layout optimization together with these components have been in the satellite module, and finally select the one with the best fitness as its initial assignment. At the same time, these components have been in the satellite module will be evaluated by their moment of inertia to decide whether they leave the current supporting surfaces and move to another or not. The layout optimization algorithm uses the differential evolution (DE) and random mutation operation to optimize the coordinates and orientations of components, respectively. The performance of the proposed algorithm is finally evaluated on a simplified satellite case. Experimental results show the proposed algorithm outperforms other two algorithms that did not consider component assignment in computational accuracy.     

Sequential optimization approach for nesting and cutting sequence in laser cutting

The economy of the laser cutting process depends on two productivity issues: (i) nesting, a classic problem of finding the most efficient layout for cutting parts with minimum material waste; (ii) cutting sequence, which targets the optimal sequence of edges of the parts to be cut for minimum cycle time. This paper presents a two stage sequential optimization procedure for nesting and cutting sequence for the objectives of maximizing material utilization and minimization of ideal (non-cut) travel distance of laser cut tool. However, the focus of this paper is the development of solution technique for optimal cutting sequence to any given layout. Simulated annealing algorithm (SAA) is considered to evolve the optimal cutting sequence. The proposed SAA is illustrated with the optimal material utilization layout obtained using sheet cutting suite software, a professional rectangular nesting software package. The robust test carried out with five typical problems shows that the SAA proposed for cutting sequence is capable of providing near optimal solutions. The performance comparison with two literature problems reveals that the proposed SAA is able to give improved result than GA and ACO algorithms.     

基于ACIS属性机制的产品模型信息存储设计与实现

“基于产品模型族的数字化产品建模工具软件”的存储功能主要运用ACIS的属性机制和ACIS支持VC开发的AMFC组件来宴现。本文着重阐述了用ACIS属性机制构造应用程序自定义数据的方法,以及运用ACIS提供的API实现SAT文件的读写。本方法为实现产品信息的非几何数据存储提供了新的思路。     

Task-specific performance effects with different numeric keypad layouts

Two commonly used keypad arrangements are the telephone and calculator layouts. The purpose of this study was to determine if entering different types of numeric information was quicker and more accurate with the telephone or the calculator layout on a computer keyboard numeric keypad. Fifty-seven participants saw a 10-digit numeric stimulus to type with a computer number keypad as quickly and as accurately as possible. Stimuli were presented in either a numerical [1,234,567,890] or phone [(123) 456-7890] format. The results indicated that participants' memory of the layout for the arrangement of keys on a telephone was significantly better than the layout of a calculator. In addition, the results showed that participants were more accurate when entering stimuli using the calculator keypad layout. Critically, participants' response times showed an interaction of stimulus format and keypad layout: participants were specifically slowed when entering numeric stimuli using a telephone keypad layout. Responses made using the middle row of keys were faster and more accurate than responses using the top and bottom row of keys. Implications for keypad design and cell phone usage are discussed.     

Introducing solid objects into a constraint modelling system

A constraint modelling system called RASOR allows the constraints between design parameters to be investigated by a designer. Some simple geometric entities are provided. The ACIS solid modeller provides procedures for handling solid objects. An integrated system in which ACIS solids are defined and manipulated by RASOR commands has been achieved. The use of constraints is illustrated with reference to the assembly of the links of a mechanical system.