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.

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.

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.

Computer-Aided Process Planning for Turned Parts Using Fundamental and Heuristic Principles

1992 ◽  
Vol 114 (1) ◽  
pp. 31-40 ◽  
Author(s):  
U. P. Korde ◽  
B. C. Bora ◽  
K. A. Stelson ◽  
D. R. Riley
Keyword(s):  
Process Planning ◽  
Search Algorithm ◽  
Optimality Criteria ◽  
Machining Processes ◽  
Critical Material ◽  
Computer Aided Process Planning ◽  
Process Plans ◽  
Computer Aided ◽  
Turned Parts ◽  
Manufacturability Evaluation

Research on generative computer-aided process planning (CAPP) for turned parts using combined fundamental and heuristic principles is presented. The rationale for the process planning approach is that many preconditions of machining processes can be expressed as a small number of domain principles. The domain is defined by processes and the part description as features for simple turned parts. The motivation is to detect faulty designs early on in the design process. Preliminary designs defined by features are first evaluated using manufacturability rules in a rule-based expert system, developed in LISP. Manufacturability rules are based on feature properties such as accessibility, stability, and critical material thickness. The rules were acquired from design and manufacturing personnel from industry through interviews. Parts that satisfy the manufacturability checks are used to generate all feasible process plans. A search algorithm selects the “best” process plan from the feasible set. Process plans are generated and subsequently optimized using two distinct sets of feasibility and optimality criteria which may be either fundamental or heuristic in nature. The presently incorporated criteria successfully restrict the set of plans to a small number without missing any apparently feasible process plans. Manufacturability evaluation, feasible process plans, and optimal process plans for actual industrial parts have been obtained and compared.

An ant colony approach to operation sequencing optimization in process planning

2016 ◽  
Vol 231 (3) ◽  
pp. 470-489 ◽  
Author(s):  
Quanwei Hu ◽  
Lihong Qiao ◽  
Guanwei Peng
Keyword(s):  
Ant Colony Optimization ◽  
Process Planning ◽  
Optimization Algorithm ◽  
Ant Colony ◽  
Local Optimum ◽  
Ant Colony Optimization Algorithm ◽  
Operation Sequencing ◽  
Computer Aided Process Planning ◽  
Process Plans ◽  
Computer Aided

Computer-aided process planning is an important component for linking design and manufacturing in computer-aided design/computer-aided process planning/computer-aided manufacturing integrated manufacturing systems. Operation sequencing in computer-aided process planning is one of the most essential tasks. To solve the problem and acquire optimal process plans, operation sequencing is modeled as a combinatorial optimization problem with various constraints, and a novel modified ant colony optimization algorithm is developed to solve it. To ensure the feasibility of process plans, constrained relationships considered among operations are classified into two categories called precedence constraint relationships and clustering constraint relationships. Operation precedence graph based on constrained relationships is formed to get visual representation. To ensure good manufacturing economy, in the mathematical model for optimization, total weighted production cost or weighted resource transformation time related to machine changes, setup changes, tool changes, machines and tools is utilized as the evaluation criterion. To avoid local optimum and enhance global search ability, adaptive updating method and local search mechanism are embedded into the optimization algorithm. Case studies of three parts are carried out to demonstrate the feasibility and robustness of the modified ant colony optimization algorithm, and some comparisons between the modified ant colony optimization algorithm and previous genetic algorithm, simulated annealing algorithm, tabu search and particle swarm optimization algorithm are discussed. The results show that the modified ant colony optimization algorithm performs well in the operation sequencing problem.

A Knowledge Base Approach for Tolerancing in Computer-Aided Process Planning

1999 ◽  
Author(s):  
Jhy-Cherng Tsai ◽  
Weirong Tsai
Keyword(s):  
Knowledge Base ◽  
Process Planning ◽  
Knowledge Bases ◽  
Computer Aided Process Planning ◽  
Base Approach ◽  
Process Plans ◽  
Machining Feature ◽  
Computer Aided ◽  
Set Up ◽  
Feature Database

Abstract This paper presents a knowledge-base approach that assists a designer to evaluate possible process plans and associated costs based on tolerancing specifications of the designed part. It is an effort to take dimensional tolerances into computer-aided process planning (CAPP) for cylindrical parts through the usage of databases and knowledge bases. Geometric features with tolerancing specifications in a CAD system are first used to determine possible machining operations that can achieve the specified tolerances based on data from the machining feature database, the process precision grade database, and the precision grade database. Process plans are then generated based on rules and knowledge from process sequence knowledge base and the machining feature database. Possible process plans are further organized as a graph. Optimal process plan with least cost is then selected by searching through the graph. This is achieved based on machine set-up and operation costs that are derived from the machine tool resource database, the process parameter database, and the machine set-up and operation cost database. A CAPP software prototype supporting tolerance design on the AutoCAD platform is also demonstrated with examples to illustrate this approach.

Temporal reasoning in process planning

1999 ◽  
Vol 13 (2) ◽  
pp. 91-104 ◽  
Author(s):  
MIRA BALABAN ◽  
DAN BRAHA
Keyword(s):  
Process Planning ◽  
Constraint Satisfaction ◽  
Constraint Satisfaction Problem ◽  
Temporal Reasoning ◽  
Temporal Constraint ◽  
Computer Aided Process Planning ◽  
Process Plans ◽  
Computer Aided ◽  
Manufacturing Environments ◽  
Intelligent Computer

Computer-aided process planning has been recognized as an important tool for coordinating the different operations involved in making the product. While temporal knowledge is central to the design of efficient and reliable process plans, little attention is given to the integration of process planning and temporal processing and reasoning. To fill the void, we propose in this paper a practical approach, which is inspired by the framework of Temporal Constraint Satisfaction Problem (TCSP), to integrate process planning and temporal reasoning. We show that a TCSP formulation is a subset of a formulation using a reified temporal logic, and discuss the advantages of using such a restricted model. To reflect more realistic process planning encountered in real manufacturing environments, we present a model, called n-TCSP, which is a generalization of the TCSP framework. We envision the proposed temporal reasoning framework as one of the modules in the evolving new intelligent computer-aided process planning.

The Generation of Machining Process Plans Using a Haptic Virtual Reality System

2012 ◽  
Author(s):  
C. A. Fletcher ◽  
J. M. Ritchie ◽  
T. Lim
Keyword(s):  
Process Planning ◽  
Mental Workload ◽  
Limited Range ◽  
Research Area ◽  
Milling Process ◽  
Machining Process ◽  
Shop Floor ◽  
Computer Aided Process Planning ◽  
Process Plans ◽  
Wide Range

Computer Aided Process Planning (CAPP) links the design and manufacture of a machined product defining how the product itself will be manufactured. Decisions made during this phase can have a significant impact on product cost, quality and build time; therefore, it is important that process planners have intuitive tools to aid them in effectively creating process plans. However, in spite of being a strong research area, the actual application of CAPP systems in industry is limited and new modern 3D digital tools in this area have not been researched to any real degree. Traditional process planning is carried out either manually or via a CAPP interface and, from this activity, a set of instructions are generated for the shop floor. However, these CAPP processes can be time consuming and subject to inconsistencies. Current research seeks to automate the generation of work instructions by using previous designs and/or artificial intelligence. However, due to the complexity of manufacturing a wide range of products, the limited range of tools available and differing skills of the workforce, it is difficult to reach a generic solution for practical application. The novel pilot study given in this paper presents one of the first pieces of research comparing and contrasting a traditional manual approach to machined part process planning with an alternative haptic virtual environment. Within this, an operator can simulate the machining of a simple part using a virtual drilling and milling process via a haptic routing interface. All of the operator input is logged in the background with the system automatically generating shop floor instructions from this log file. Findings show that users found the virtual system to be more intuitive and required less mental workload than traditional manual methods. Also their perceptions for the future were that they would need less support for learning and would progress to final planning solutions more quickly.

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