International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395 -0056
Volume: 04 Issue: 06 | June -2017 www.irjet.net p-ISSN: 2395-0072
© 2017, IRJET | Impact Factor value: 5.181 | ISO 9001:2008 Certified Journal | Page 858
Operation Sequencing and Machining Parameter Selection in CAPP for
Cylindrical Part using Hybrid Feature Based Genetic Algorithm and
Expert System
Abhishek Agrawal
1
, Dr. R.S. Rajput
2
, Dr. Nitin Shrivastava
3
1
Ph.D Scholar, Dept of Mechanical Engg, UIT-RGPV Bhopal, Madhya Pradesh, INDIA
2
Professor, Dept of Mechanical Engg & Director, UIT-RGPV Bhopal, Madhya Pradesh, INDIA
3
Assistant Professor, Dept of Mechanical Engg, UIT-RGPV Bhopal, Madhya Pradesh, INDIA
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Abstract - Computer-Aided Process Planning (CAPP) is an
important interface between Computer-Aided Design (CAD)
and Computer-Aided Manufacturing (CAM) in computer-
integrated manufacturing environment. Process planning is
concerned with the preparation of route sheets that list the
sequence of operations and work centers that require
producing the product and its components. In any CAPP
system, selection of the machining operations sequence is one
of the most critical activities for manufacturing a part as per
the technical specification and the part drawing. The
operation-sequencing problem in process planning is
considered to produce a part with the objective of minimizing
number of set-ups, maximizing machine utilization and
minimizing number of tool changes and a single sequence of
operations may not be the best for all the situations in a
changing production environment with multiple objectives. In
general, the problem has combinatorial characteristics and
complex precedence relations, it makes the problem more
difficult to solve. To overcome these difficulties, by combining
Genetic Algorithm (GA) and Expert system (EX) in an
appropriate way a new super hybrid genetic algorithms-
expert System (S-GENEX) is developed in this research work.
The feasible sequences of operations are generated using this
hybrid algorithm, based on the inputs precedence cost matrix
(PCM).
The present work is divided into two phases, the GA and
Expert System. During the first phase, GA generates an initial
population randomly. Then cross over and mutation operators
are imposed for offspring generation based on the initial
population. The cross over and mutation sites are selected
randomly. This process is repeated for a period of generations
for attaining an optimum solution. Expert System is used for
selecting the machining parameters for facing, turning and
boring operations for three types of materials. A program is
developed in C++ based on proposed algorithm, to check its
validity and the results are compared with the previous work.
The main contribution of this work focuses on reducing the
optimal cost with a lesser computational time along with
generation of more alternate optimal feasible sequences.
Key Words: Computer-Aided Process Planning (CAPP);
Computer-Aided Manufacturing (CAM); Computer-Aided
Design (CAD); Genetic Algorithm; Expert System;
Operation Sequencing.
1. INTRODUCTION
Today machining process planning has to yield such results
that are to give maximum productivity and to ensure
economy of manufacturing. Today the market has an ever
changing demand for new products, which require shorter
development cycle. An important part of the product
development cycle is manufacturing process planning.
Shorter process planning time can lead to the use of
machining parameters that are not optimal and this can lead
to the greater cost of production. A human process planner
selects proper machining parameters by using not only his
own experience and knowledge but also from handbooks of
technological requirements, machine tool, cutting tool and
selected part material.
This manual selection can be slow and does not have to
give optimal results. To overcome that problem, machining
process planning has gone automated, by the use of
Computer-Aided Process Planning (CAPP) system. In
addition to operation sequence and machining parameters,
the CAPP system should also be able to automatically choose
machine and cutting tool while taking in consideration part
material. In this paper, the focus is given to cutting
parameters optimization. Cutting parameters, such as
cutting depth, number of passes, feed rate and machining
speed have influence on overall success of machining
operation [1,2]. In order to conduct optimization, a
mathematical model has to be defined. It is not always easy
to define a model that can be expressed by pure analytical
functions. Besides, cutting parameters optimization presents
a multi-objective optimization problem. So, the classical
mathematical methods such as linear programming would
not work with such input data.
There is also a problem of finding local optimum. In
order to overcome these problems, this paper shows the use
of Genetic Algorithm (GA) in machining process
optimization. GA is a part of the evolutionary algorithms that
copy intelligence of nature in order to find global extremities
on the given function problem. These algorithms are based
on stochastic operations. In nature, only an entity that is able
to adapt to its surrounding is going to survive and transfer
its qualities to next generations [3,4]. Depending on
measuring the quality of entity, the proposed result is kept
or deleted. New combined results are then transferred to the