基于几何推理的装配序列自动规划研究

文章以问题规约的求解策略,以分解法规划产生的装配序列,提出与或图表达装配体拆卸序列解空间。通过求解拆卸序列与或图的解空间得到装配体的拆卸序列,将拆卸序列反向得到装配序列。为降低装配体拓扑联接图的复杂度,对作业组件做出识别。另外提出了判断零件拆卸性的三个条件,大部分零件无需进行干涉检验,而白逻辑推理即可判断是否满足拆卸条件,避免了多次试凑,具有更高的求解效率,可更广泛地用于装配序列求解。     

面向装配的CAD技术研究

面向装配的设计DFA(Design for Assembly）是并行工程的一个有效工具。本文系统阐述了DFA的发展 、意义及其与传统的考虑装配工艺性的区别;介绍DFA的主要内容和几个典型的DFA分析方法,重点分析Boothroyd-Dewhurst方法和步骤;叙述集成CAD技术的DFA应解决的问题及典型的DFA分析软件;最后总结了DFA的研究特点。     

浅谈Debug调试汇编语言程序的方法

本文浅谈了Debug在汇编语言程序上机调试中的基本步骤和方法,帮助学生如何利用Debug工具更好地学习汇编语言,对于汇编语言教学具有一定的参考价值。     

迅速掌握8088/8086指令系统的教学方法

介绍了一种快速掌握汇编语言指令系统的方法,对学生学习汇编语言程序设计有一定的帮助。     

板式塔总装图参数化绘图研究

板式塔总装图的绘制是板式塔设计的主要工作之一，工作量大。通过对板式塔总体结构特点及其视图表示法的分析总结，结合行业标准及有关规定，将其总装图划分为几种规范化的组件，包括塔体、塔板及开孔结构等部分。根据各组件及总体表达方案的特点建立组件对应的子程序库、数据库、总装图数据文件及相关规则库，在此基础上，提出了板式塔总装图参数化绘图方法，并借助ＡＵＴＯＬＩＳＰ语言在ＡＵＴＯＣＡＤ１２环境中编程实现，提高绘图效率约２０倍。由于板式塔总装图的复杂性，未能解决文字及符号等的自动标注，有待完善。     

Integrated knowledge-based Petri net intelligent flexible assembly planning

Automatic assembly planning is recognized as an important tool for reducing manufacturing costs in concurrent product and process development. A novel knowledge-based Petri net (KBPN) is defined, based on the incorporation of expert systems into the usual Petri nets, and used for a unified assembly knowledge representation scheme. A KBPN-approach integrated with a sequence generation algorithm is proposed for the modeling, planning, simulation, analysis and evaluation of the flexible assembly system (FAS). The developed KBPN-based assembly planning system (KAPS) can automatically adjust the deviations between the theoretical planning parameters and the process parameters of real assembly operations to guarantee the best strategies and plans (sequences) for flexible assembly. The research findings are exemplified with a simple assembly to show the effectiveness of the method.     

A PSO and a Tabu search heuristics for the assembly scheduling problem of the two-stage distributed database application

The assembly flowshop scheduling problem has been addressed recently in the literature. There are many problems that can be modeled as assembly flowshop scheduling problems including queries scheduling on distributed database systems and computer manufacturing. The problem has been addressed with respect to either makespan or total completion time criterion in the literature. In this paper, we address the problem with respect to a due date-based performance measure, i.e., maximum lateness. We formulate the problem and obtain a dominance relation. Moreover, we propose three heuristics for the problem: particle swarm optimization (PSO), Tabu search, and EDD. PSO has been used in the areas of function optimization, artificial neural network training, and fuzzy system control in the literature. In this paper, we show how it can be used for scheduling problems. We have conducted extensive computational experiments to compare the three heuristics along with a random solution. The computational analysis indicates that Tabu outperforms the others for the case when the due dates range is relatively wide. It also indicates that the PSO significantly outperforms the others for difficult problems, i.e., tight due dates. Moreover, for difficult problems, the developed dominance relation helps reduce error by 65%.