scholarly journals Optimization of Operation Sequencing in CAPP Using Superhybrid Genetic Algorithms-Simulated Annealing Technique

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
G. Nallakumarasamy ◽  
PSS. Srinivasan ◽  
K. Venkatesh Raja ◽  
R. Malayalamurthi
Keyword(s):  
Genetic Algorithms ◽  
Simulated Annealing ◽  
Solution Space ◽  
Computer Integrated Manufacturing ◽  
Computational Time ◽  
Shop Floor ◽  
Production Environment ◽  
Computer Aided Process Planning ◽  
Space Reduction ◽  
Computer Aided

Computer-aided process planning (CAPP) is an important interface between computer-aided design (CAD) and computer-aided manufacturing (CAM) in computer-integrated manufacturing environment. A problem in traditional CAPP system is that the multiple planning tasks are treated in a linear approach. This leads to an overconstrained overall solution space, and the final solution is normally far from optimal or even nonfeasible. A single sequence of operations may not be the best for all the situations in a changing production environment with multiple objectives such as minimizing number of setups, maximizing machine utilization, and minimizing number of tool changes. In general, the problem has combinatorial characteristics and complex precedence relations, which makes the problem more difficult to solve. The main contribution of this work is to develop an intelligent CAPP system for shop-floor use that can be used by an average operator and to produce globally optimized results. In this paper, the feasible sequences of operations are generated based on the precedence cost matrix (PCM) and reward-penalty matrix (REPMAX) using superhybrid genetic algorithms-simulated annealing technique (S-GENSAT), a hybrid metaheuristic. Also, solution space reduction methodology based on PCM and REPMAX upgrades the procedure to superhybridization. In this work, a number of benchmark case studies are considered to demonstrate the feasibility and robustness of the proposed super-hybrid algorithm. This algorithm performs well on all the test problems, exceeding or matching the solution quality of the results reported in the literature. 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. Also, the proposed S-GENSAT integrates solution space reduction, hybridization, trapping out of local minima, robustness, and convergence; it consistently outperformed both a conventional genetic algorithm and a conventional simulated annealing algorithm.

Using Automatic Feature Recognition to Interface CAD to CAPP

1992 ◽  
Author(s):  
Eric Wang
Keyword(s):  
Pattern Matching ◽  
Feature Recognition ◽  
Scale Up ◽  
Fundamental Difference ◽  
Computer Integrated Manufacturing ◽  
Semantic Gap ◽  
Recognition Method ◽  
Computer Aided Process Planning ◽  
Computer Aided ◽  
Automatic Feature Recognition

Abstract Interfacing CAD to CAPP (computer-aided process planning) is crucial to the eventual success of a fully-automated computer-integrated manufacturing (CIM) environment. Current CAD and CAPP systems are separated by a “semantic gap” that represents a fundamental difference in the ways in which they represent information. This semantic gap makes the interfacing of CAD to CAPP a non-trivial task. This paper argues that automatic feature recognition is an indispensable technique in interfacing CAD to CAPP. It then surveys the current literature on automatic feature recognition methods and systems, and analyzes their suitability as CAD/CAPP interfaces. It also describes a relatively recent automatic feature recognition method based on volumetric decomposition, using Kim’s alternating sum of volumes with partitioning (ASVP) algorithm. The paper’s main theses are: (1) that most previous automatic feature recognition approaches are ultimately based on pattern-matching; (2) that pattern-matching approaches are unlikely to scale up to the real world; and (3) that volumetric decomposition is an alternative to pattern-matching that avoids its shortcomings. The paper concludes that automatic feature recognition by volumetric decomposition is a promising approach to the interfacing of CAD to CAPP.

Computer-Aided Process Planning: A Path to Just-in-Time Manufacturing for Shipyards

1988 ◽  
Vol 4 (03) ◽  
pp. 197-215
Author(s):  
Richard L. DeVries
Keyword(s):  
Real Time ◽  
Process Planning ◽  
Group Technology ◽  
Shop Floor ◽  
Just In Time ◽  
Time Data ◽  
Computer Aided Process Planning ◽  
Computer Aided ◽  
Time Basis ◽  
Manufacturing Data

The use of computers to improve the productivity of U.S. shipyards has never been as successful as hoped for by the designers. Many applications were simply the conversion of an existing process to a computerized process. The manufacturing database required for the successful application of computer-aided process planning (CAPP) to the shipyard environment requires a "back-to-basics" approach, one that can lead to control of the processes occurring in the fabrication and assembly shops of a shipyard. The manufacturing database will not provide management feedback designed for the financial segment of the shipyard (although it can be converted to be fully applicable): it provides "real-time" manufacturing data that the shop floor manager can utilize in his day-to-day decisions, not historical data on how his shop did last week or last month. The computer is only a tool to be used to organize the mountains of manufacturing data into useful information for today's shop manager on a "real time" basis. The use of group technology to collect similar products, the use of parameters to clearly identify work content, the use of real-time efficiency rates to project capacity and realistic schedules, and the use of bar codes to input "real time" data are all tools that are part of the process—tools for the shop floor manager of tomorrow.

A Formal Approach to Integrating Computer-Aided Process Planning and Shop Floor Control

1994 ◽  
Vol 116 (1) ◽  
pp. 108-116 ◽  
Author(s):  
H. Cho ◽  
A. Derebail ◽  
T. Hale ◽  
R. A. Wysk
Keyword(s):  
Process Planning ◽  
Shop Floor ◽  
Task Graph ◽  
Shop Floor Control ◽  
Formal Approach ◽  
Computer Aided Process Planning ◽  
Process Plans ◽  
Computer Aided ◽  
Floor Control ◽  
Planning Function

A formal approach for integrating Computer-Aided Design (CAD), Computer-Aided Process Planning (CAPP), and shop floor control for rotational components is presented in this paper. It is assumed that this approach will be implemented within the framework of a three level hierarchical CIM architecture that consists of the following levels in the hierarchy: shop floor, workstation and equipment (Joshi et al., 1991). Our approach to CAPP consists of machining feature identification, definition, classification, representation, and reasoning, provided through a CAD model of a product. Geometric entities are identified from a Drawing Exchange Format (DXF) file. The identified entities form the basis for the construction of primitive manufacturing features. The primitive features are assembled together based upon the precedence among features, into a graph, called a feature graph. However, the primitive features may or may not be manufacturable in terms of depth of cut, tool geometry, surface finish, and material handling required. Hence it is necessary to convert the feature graph into a manufacturing task graph, which consists of specifications of alternative functional tasks that are manufacturable. The task graph may be converted into a hierarchical set of process plans, based on the planning criteria at each level in the control hierachy, to reflect the processing requirements at each level. The shop planning function decomposes the task graph into a set of workstation level plans. Each workstation level plan is aggregated into a set of equipment level process plans by the workstation planning function. The equipment level plan is converted into a unique task sequence by the equipment planning function. This sequence is then executed according to specifications by the equipment level execution function. Provision of alternative routes in process plans provides for flexible means of on-line planning and control.

Study on Integration of Computer Aided Process Planning System and PDM System

2013 ◽  
Vol 416-417 ◽  
pp. 919-924
Author(s):  
Hong Xia Yang ◽  
Wei Dong Chen ◽  
Hua Sheng Feng
Keyword(s):  
Product Design ◽  
Process Planning ◽  
Rapid Development ◽  
Computer Integrated Manufacturing ◽  
Planning System ◽  
Strong Basis ◽  
Computer Technique ◽  
Computer Aided Process Planning ◽  
Process Planning System ◽  
Computer Aided

With the rapid development of modern science and technology and computer technique, modern enterprise faces new challenges for product design, production, management, market planning and sales. The products of enterprises develop towards diversification, serialization and individualization. Technological design is important in product manufacturing process and is a bond of product design and actual production. Therefore, modern enterprises need to develop computer aided process planning system to improve the quality and efficiency of process design of the enterprise. Starting from the requirements of enterprises on computer aided process planning systems and combining the existing Web technology, the paper proposes the study on integration of computer aided process planning system and PDM system. The development and application of the system not only provides strong support for enterprises realizing rapid design and manufacture and strong basis for enterprises realizing computer integrated manufacturing system, but also makes informationization degree, economic benefit and social benefit of enterprises improve greatly.

scholarly journals Cryptanalysis of Mono-Alphabetic Substitution Ciphers using Genetic Algorithms and Simulated Annealing

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Shalini Jain ◽  
Nalin Chhibber ◽  
Sweta Kandi
Keyword(s):  
Genetic Algorithms ◽  
Simulated Annealing ◽  
Computational Efficiency ◽  
Solution Space ◽  
The Third ◽  
High Degree ◽  
Language Text ◽  
Substitution Cipher

In this paper, we intend to apply the principles of genetic algorithms along with simulated annealing to cryptanalyze a mono-alphabetic substitution cipher. The type of attack used for cryptanalysis is a ciphertext-only attack in which we don’t know any plaintext. In genetic algorithms and simulated annealing, for ciphertext-only attack, we need to have the solution space or any method to match the decrypted text to the language text. However, the challenge is to implement the project while maintaining computational efficiency and a high degree of security. We carry out three attacks, the first of which uses genetic algorithms alone, the second which uses simulated annealing alone and the third which uses a combination of genetic algorithms and simulated annealing.

Development of a Welding Protocol for Automated Shipyard Manufacturing Systems

1997 ◽  
Vol 13 (01) ◽  
pp. 48-56
Author(s):  
Joel Milano ◽  
Ben Kassel ◽  
Douglas Mauk
Keyword(s):  
Mass Production ◽  
Computer Aided Design ◽  
Manufacturing Systems ◽  
Computer Integrated Manufacturing ◽  
Production Environment ◽  
Model Data ◽  
Product Model ◽  
Computer Aided ◽  
Close Relationship ◽  
Aided Design

Robotic manufacturing systems have provided improvements in productivity and quality in the automotive and semiconductor industries. Shipbuilding, however, is a one-of-a-kind manufacturing process and as such embodies a completely different set of problems than the mass production environment. The planning for robotics applications in shipbuilding must be done for each unique component and, therefore, must be done efficiently to achieve the benefits of automation. This will require a close relationship between computer-aided design (CAD), computer-aided manufacturing (CAM), computer-integrated manufacturing (CIM), and the manufacturing systems used on the waterfront. One of the major efforts to be performed is the integration of these processes through the timely presentation of information. One of the tools that can be used to integrate these processes is the Standard for the Exchange of Product Model Data (STEP). This paper will identify the relevant components of a STEP applications protocol (AP) for welding which can be applied to shipbuilding and outline the efforts required to bring it into existence.

Programmable Support Functions to Assist Process Planning for Aeronautical Parts Manufacturing

2014 ◽  
Author(s):  
Nikolaos A. Fountas ◽  
Constantinos I. Stergiou ◽  
Nikolaos M. Vaxevanidis
Keyword(s):  
Process Planning ◽  
Computer Aided Design ◽  
Shop Floor ◽  
Support Functions ◽  
Computer Aided Process Planning ◽  
Software Application ◽  
Process Plans ◽  
Computer Aided ◽  
Technical Instructions ◽  
Parts Manufacturing

Despite the fast development and the continuous evolution of computer-aided systems for product design, analysis and manufacturing, an unlinked gap appears between the interfaces of computer-aided design (CAD) and computer-aided process planning (CAPP) modules. Various CAPP systems have been built to address this problem and forward a “passage” to link the design phase and the planning of manufacturing processes; hence, providing precise technical instructions in the shop-floor. To support the manufacturing trends and contribute to the research efforts for the realization of precise, reliable and efficient process plans, a set of programmable support functions are presented in the form of an object-oriented software application that enable process planners to produce accurate process plans for aircraft parts and components.

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