The proposed systemis implemented on PC (Pentium 4 CPU, 2.4 GHz, 256 MB of RAM)with Autodesk AutoCAD 2004. The production rules incorporatedin all the modules of the proposed intelligent system have beentherefore coded in AutoLISP language. The production rules andthe knowledge base of the system are linked together by an infer-ence mechanism, which makes use of forward chaining. In forwardchaining, the user interactively supplies system data or facts aboutthe problem to be solved. The system works with input informa-tion supplied by the user coupled with knowledge stored in theknowledge base, to draw conclusions or recommendations. Thesystem searches the IF conditional data to determine which rulesare satisfied by the given facts. Whenever a particular IF conditionis found to be satisfied then the THEN portion of the rule is acti-vated leading to a conclusion or an advice. The developed knowl-edge-based system INTPDIE overall comprises of more than 1000production rules of IF-THEN variety. A sample of production rulesincorporated in various modules of the system INTPDIE is givenin Table 1.3.2. Organization of the systemAs the progressive die design process comprises of many activ-ities, the whole system INTPDIE has been structured into varioussub-systems, modules and sub-modules. Organization of the devel-oped system INTPDIE is shown in Fig. 1. The various modules andsub-system of the system INTPDIE are briefly described as under:3.2.1. Module CCKBSThe module CCKBS is developed for checking the design fea-tures of sheet metal parts from manufacturability point of view.The module is capable of checking the part design features suchas size of blank, size of holes, hole pitch, corner radius, distanceof the internal features from the edge of the part, distance betweentwo internal features, width of recesses or slots or projections,bend corner radius etc. It also recommends the minimum scrapweb allowances for manufacturing the parts on a progressive die.This module incorporates an interface for displaying friendlyprompts to guide the user during a consultation session. The datasupplied by the user is also stored in a file, called as
COMP.DATfor use in subsequent modules.3.2.2. Module SELDIEThe module SELDIE is developed to assist the die designer andprocess planner in the selection of a suitable type of die for manu-facturing of sheet metal parts. The module is designed to take re-quired inputs such as production requirement and tolerance onthe part from the part data file COMP.DAT. The user is also invitedto enter other required inputs involving number and type of sheetmetal operations through the prompt area of AutoCAD. As soon asthe user enters these inputs, the module imparts intelligent advicefor selection of suitable type of die.3.2.3. Module MAXUTLThe module MAXUTL is developed for determining the angle oforientation of blank. The module incrementally alters the orienta-tion of blank by 1 and then calculates the material utilization ofsheet at each angle till the blank has been rotated by 180 fromits initial position. The orientation that has the maximum utiliza-tion ratio is the optimal. The outputs of the module are automati-cally stored in a data file labeled as MAXUTL.DAT.3.2.4. Sub-system ISSLDThe sub-system ISSLD is developed for intelligent design ofstrip-layout for metal stamping work on progressive die. The exe-cution of the sub-system is shown through a flow chart in Fig. 2.This sub-system comprises of six modules. The first module OPR-PLAN determines the type of sheet metal operations required tomanufacture the part. The module invites the user to supply rele-vant input data namely dimensional tolerance and geometrical fea-tures of the part. The outputs of this module are in the form ofrecommendations for the type of sheet metal operations requiredto manufacture the part. The next module OPRSEQ of the sub-sys-temdetermines the sequencing of recommended sheetmetal oper-ations. It takes its input directly from the output data fileOPRPLAN.DAT generated during the execution of module OPR-PLAN. The module PLTSEL is developed for selection of properpiloting scheme for positioning the strip accurately in each stationof progressive die. The next module OPRSTAGE is developed for imparting expert advices for the number of stations required andpreferred staging of operations on progressive die. This modulehas two sub-modules namely OPRSTAGE1 and OPRSTAGE2. Thefirst sub-module has been designed to impart general expert ad-vices for staging of operations. The second sub-module OPRSTAGE2has been developed for deciding number of stations required andoperations to be accomplished at each station of progressive die.The module OPRSTAGE takes its inputs from the output data fileOPRSEQ.DAT generated during the execution of module OPRSEQ,and also invites the user to enter job specific data as per the partfeatures. The module SWLSEL determines the proper size of sheetmetal strip. This module has been structured into two sub-mod-ules, namely SWLSEL1 and SWLSEL2. 级进模自动设计系统英文文献和中文翻译(2):http://www.youerw.com/fanyi/lunwen_30306.html