菜单
  

    constraint graph.  Homem de Mello and Sanderson  [SI took  a  diffexent
    approach  by  representing  all  the  assembly plans explicitly  using  an
    AND/OR  graph.  Any  feasible assembly plan cOneSpOndS  to  a tree in the
    graph. They have proved that a complete and cOrrect set of precedence
    relationships can  be  derived from the  AND/OR  graph. Since che  precedence
    constraints are  determined by the  geomq  of a product, it is more desirable
    to obtain the precedence  relations directly from  the  geometry of the  assem-
    bly (i.e.,  the  CAD model of  the assembly) and  then generate assembly
    plans, rather  than  vice versa.
    Not all of the  assembly plans generated f"  the  precedence relation-
    ships are efficient  or  even  feasible for  a  particular assembly cell. Both
    Homem de Mello [9] and Wolter [I61 defined criteria, such as  degrees of
    This work was supported in part by  the National Science Found.ticn un&r  Orwt
    CDR  8803017 to the Engineering  Research Center  for Jntelligent Manufacturing
    Systems  and a grant ham the Ford Fund. freedom of  subassemblies, and  directionality  of  assembly maling tasks, e..
    to select optimal  assembly plans frun all the  possible  onm.  But MQC  of
    cell, such as  fixture  and  001  stkctiaas.  Therefac. the  optimal  plan UIUS
    selected  may still  be  infeasible for a  given  nbly  cell.
    ~paper&scribesanautmraticasscmblyplanniqgsystun. Theiaput
    to the  system is a CAD desziptioa  of a product  and  an assembly cell m
    which  the  product  is to be assembled. The  output ofthe  is an
    efficient feasible assembly plan subject  to  the  ltaoucc  coastrun  tsofthe
    given BssemMy cell. The plan nat only contains the  sequence of  asembly
    mating  tasks to be done, but  also the  fix-  con6guration end tool
    speciscations  for each of meSe mating  tasks.
    2.  Assembly Planning System
    these  criteria is directly rem  to  the  rcsolmx CQnstrSints of  an  BssQnbly
    The proposed  assembly planning system cax+ts  of five &  modules:
    base,  simulated world model. and  sssmbly planna.  The funchon of  each
    major  module  is described  in the  following subsections.
    2.1. World Database
    assembly and  a model of assembly  cell.
    tuple, < C ,  R  >  in which
    world  databa%  knowledge acquisition nwch"  .  Planning.lolowledge
    The wmld  database consists of  two  modules, a relational  model  of
    Definition 1. A relational malcl of an  ncomponent assembly is a two
    C=  (c1 ,  c2,  9.-  ,  c.)  isa set  of symbolsrepmenting components in
    the assembly.
    R =  [ rl ,  rz, ..-  ,  r,  )  is a set of  four tuples representing relations
    between  components  of the  assembly. when? m = Ci  =  n(n -  1)R.
    ri = < c,,  ,  cq ,  A  ,  TN  >. whae cp ,  cq E C, A  is a 4x4 homogene-
    ous transformatii  matrix  representing spawfre~mhip  between
    components c,,  and cq.
    =  {NULL,  if no  contacts  exist  between  components c,,  and  cq
    PI
    < TRb ,  TR,  ,  Typ,  Stclbility >  , XconUasmistbetarknc, mdc,
  1. 上一篇:数字化制造英文文献和中文翻译
  2. 下一篇:自动冲压模具英文文献和中文翻译
  1. 计算机辅助工艺规划CAPP系...

  2. 冲压工艺规划和级进模设...

  3. 零件识别的计算机辅助装...

  4. 大棚自动滴灌系统英文文献和中文翻译

  5. 自动刷镀技术的革新英文文献和中文翻译

  6. 基于虚拟装配的运动学分...

  7. S7-200自动化系统英文文献和中文翻译

  8. 乳业同业并购式全产业链...

  9. 电站锅炉暖风器设计任务书

  10. java+mysql车辆管理系统的设计+源代码

  11. 大众媒体对公共政策制定的影响

  12. 中考体育项目与体育教学合理结合的研究

  13. 河岸冲刷和泥沙淤积的监测国内外研究现状

  14. 当代大学生慈善意识研究+文献综述

  15. 酸性水汽提装置总汽提塔设计+CAD图纸

  16. 十二层带中心支撑钢结构...

  17. 杂拟谷盗体内共生菌沃尔...

  

About

751论文网手机版...

主页:http://www.751com.cn

关闭返回