Abstract:
Modern manufacturing industry has recognized the development and adoption of
computer inteb'Taledmanufacturing (elM) technologies as an effectivc and decisive
lactor to remain competitive in thc market. Computer aided proecss planning
(CAPP) plays a key role for achieving elM by integrating design and manufacturing
systems. But a pedect CAPP system which considers all the complex activities of
process planning is yet to be developed. In this work, an object oriented approach
for the design and development of CAPP system has been presented, sinec objectorientation
can model complex systems efficiently. The objectives of this research
arc the development of algorithms for extraction of both external and internal
axisymmetric features of a rotational part. development of algorithms for the
sel~1.ion of blank, operations, machine and cutting tools for the generation of
process plan, the design of a system to utilize pOlential capabilities of objectoriented
technology and the dcsign of a systcm for the complete integration of
design and planning systems. An algorithm has been developed which can extract
geometric information from thc drawing file of a rotational part and recognizes both
the external and intcrnal machining features. The algorithm allows the user to
exercise his freedom and creativity in modeling a part, since it sets no predefined
sequencl: to follow during design process. Algorithms and production rules have
becn dcveloped which can select the appropriate blank, operations, machines and
cutting toob for the process plan. The integration betwecn computer aided design
(CAD) and CAPP systcms is a vital issue for the complete mtegration of
manutac:turingcnvironment. The system has been designed such that it ensures this
integration of CAD and CAPP systems. The system takes the drawing file as the
input and generates the process plan without any human involvement. The proposed
system makcs effective usc of the object-oriented teelmology. The hierarchy and
polymolJlhism features of the object orientation have been utilized such that future
modification and evolution of the planning system can be done easily. This objeetoriented
system allows effective representation of data and knowledge base used in
the plmming process. So it implements databases for part, blank, machine,
operations and culling tools effectively and future modilication of the databases can
be done casily. The system eliminates needs for central knowledgc base and
inference engine by implementing the rules in the individual objects customized for
it. Thus the system provides effcctive integration between design and planning
flUlctions. Jt can readily generate process plan for the rotational parts. The
effectiveness of the developed system has been verified jor example rotational parts
and fonnd consistent with thc real process plans.
