Study of key techniques in variant CAPP development

Key techniques in variant Computer aided process planning (CAPP) development were studied in this paper, including global design of the system, input of part´s data, generation of part´s process and its documents etc. This article designed a variant CAPP global flow, proposed a method of reading Strings from AutoCAD window by iterating block table, reading data from subject bar of part´s drawing by position, outputting data from database to AutoCAD interface by creating texts with text style IDs and adding them to the block table records of model space, filling process cards and sub-process cards with data from database, inserting drawing into subprocess cards by searching 2-layer paths. At last, with AutoCAD development platform, SQL Server background database, Object ARX and Visual C++ development tools, this article realized development of a variant CAPP system.