Manufacturing Activities Modelling for the Purpose of Machining Process Plan Generation (original) (raw)
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Modelling of manufacturing activities by process planning knowledge representation
International Journal of Simulation Modelling, 2006
Process planning is one of the key activities for product design and manufacturing. Impact of process plans on all phases of product design and manufacture requires high level of interaction of different activities and tight integration of them into coherent system. In this paper we describe a model for manufacturing activities that allows integration. The framework for integration is briefly described and the manufacturing process model that considers three dimensions of planning is explained. Than an object-oriented knowledge representation approach is presented with module for parts modeling and module for generation of process plan. Description of machining process entities and their relationships with features, machines and tools are provided. The benefits of the proposed representation, which include connection with geometric model, reduced search space and alternative plan generation, are discussed. These new contributions provide for a new generation of CAPP systems that can be adapted for various manufacturing systems and can be integrated with other CIM modules.
Feature-based generation of machining process plans for optimised parts manufacture
Journal of Intelligent Manufacturing, 2012
Efficacious integration of such CAx technologies as CAD, CAM and CAPP still remains a problem in engineering practice which constantly attracts research attention. Design by feature model is assumed as a main factor in the integration effort in various engineering and manufacturing domains. It refers principally to feature clustering and consequently operation sequencing in elaborated process plan designs. The focus of this paper is on CAPP for parts manufacture in systems of definite processing capabilities, involving multi-axis machining centres. A methodical approach is proposed to optimally solve for process planning problems, which consists in the identification of process alternatives and sequencing adequate working steps. The approach involves the use of the branch and bound concept from the field of artificial intelligence. A conceptual scheme for generation of alternative process plans in the form of a network is developed. It is based on part design data modelling in terms of machining features. A relevant algorithm is proposed for creating such a network and searching for the optimal process plan solution from the viewpoint of its operational performance, under formulated process constraints. The feasibility of the approach and the algorithm are illustrated by a numerical case with regard to a real application and diverse machine tools with relevant tooling. Generated process alternatives for complex machining with given systems, are studied using models programmed in the environment of Matlab software.
Extension of STEP-NC Data Structure to Represent Manufacturing Process Structure in CAPP System
Procedia Manufacturing, 2017
STEP-NC is a new standard for Computer Numerical Control (CNC) machine tool programming. It contains many elaborated data models for milling and turning, including the representation of parameters and geometry of machining features. The paper presents the use of STEP-NC data model for CAPP system under the development. The structure of manufacturing process was analyzed and the method to represent it using STEP-NC entities was proposed. New entities were added to store the information required by CAPP system, including the manufacturing process other than machining. Express-G data modelling language was used for this purpose.
Computers & Industrial Engineering, 1998
This paper describes the activities of Object-Oriented (OO) analysis that were implemented in order to obtain a high part representation level and to give sets of structured and hierarchical data to the Computer Aided Process Planning (CAPP) system. The OO modeling activities were carried out by using the Object-Oriented System Analysis (OOSA) method which allows careful specification of all the information contained inside the system. All the models used by this method have been described in detail to show how the OO database is defined and how it can be used by a generative CAPP system. The feature model proposed is defined by taking all the part information that can be recognized and extracted from the Computer Aided Design (CAD) model into account. The result is the design of an OO database which allows the CAPP system to use manufacturing features to define machining operation sequences of 3D workpieces. The approach proposed is generic enough to integrate any geometrical forms which can be recognized and identified from the CAD system. Hole geometry is taken as an example to show the link between the step of OO analysis and the step of knowledge representation in the Expert System which has been used to generate machining cycles. The OO database presented makes up a real solution of CAD/CAPP/CAM integration by using feature modeling.
A Knowledge Based Approach for Automatic Process Plan Generation for Machining
The present paper is aimed at developing an intelligent Computer-Aided Process Planning methodology based on application of a KBS for automatic generation of process plans for machining. It takes, as input, information about the different machining features present in the part and automatically generates a detailed sequence of machining operations including the precedence constraints, the different machining setups in accordance with the given Tool Approach Directions, the list of operations to be performed within each setup, the locating and clamping faces needed for fixturing the component as well as the setup sequence. To accomplish the above, a set of knowledge based rules have been developed and implemented using an Expert System Shell. The application of the proposed approach has been demonstrated using an example part. By using the proposed approach, it is anticipated, that process planning can be accomplished automatically and quickly by investigating a very limited amount of time making it attractive for applications in industry.
Analyzing possibilities of improving machinning process planning and optimization
Main activities of the technological preparation of production refer to the process planning and optimization. Process plans as the most significant objects of optimization in production systems are characterized by variant solutions in all stages, from the selection of raw material and manufacturing technologies, types and sequences of processes and machining operations, types and characteristics of manufacturing resources, machining parameters and strategies, with machining time, cost, accuracy and surface quality as main objective functions of process planning optimization. Main goal of this paper is to analyze the possibilities of improving technological preparation of production, or precisely, to improve process planning and optimization of manufacturing process plans through the application of feature technologies and the considered simulation technique. The application of feature technologies will be analyzed from the aspect of possible integration of product design and process planning, while the application of the simulation technique within the CAD/CAM system will test the influence of variants of machining operations and machining strategies on the process planning optimization from the aspect of machining time. process planning, optimization, feature technologies, simulation technique Two basic activities within the product development are product design and product manufacturing which ought to be integrated and connected at the greatest possible extent. Technological preparation of production represents the main integr that should meet design requirements of product designers on one hand, and to adopt manufacturing possibilities of production on the other hand [1]. Main activity of the technological preparation refers to the manufacturing process planning and optimization. The imperative of modern global production is to generate rational and optimal process plans, in accordance with the basic optimization criteria such as productivity, cost-effectiveness, machining accuracy and surface quality [2]. Process planning represents the complex multi-dimensional problem that depends on the input data and set requirements according to the observed product/s, as well as the techno-economic conditions and subjective preferences of the product designer. The most important input data for process planning are product drawings which possess information about materials, dimensions, machining accuracy, surface quality, production volume and available manufacturing resources, such as raw materials, machines, tools, fixtures, measuring instruments etc. Accordingly, various process plans can be predicted for the same manufacturing conditions and which can be evaluated using various optimization criteria [3]. ng conditions, modern CAD programming systems based on feature technologies, or the application of features in modeling, are mainly used for product design and for defining technological documentation. However, the attention of product designers is focused on realizing functional characteristics of products and parts, whereby they use features in modeling which generally do not match the typical manufacturing features. By that, the process planning, as well as the integration of CAD, CAPP and CAM systems is more difficult to achieve [4]. According to above mentioned, the first task of this paper is related to the analysis of possibilities of modeling products by applying features that match with manufacturing features which are used in machining processes. In this way, it is intended to facilitate the manufacturing process planning, as well as the integration of activities of product design and process planning through direct application of features from CAD systems to machining process within CAM systems.
A New Method for Manufacturing Process Autonomous Planning in Intelligent Manufacturing System
Lecture Notes in Business Information Processing, 2019
This paper presents a new method for autonomous computer aided process planning (A-CAPP) in intelligent manufacturing system, in which the related input and output of the system are discussed on the basis of comparative analysis of traditional CAPP. The crucial functional components of the A-CAPP system, such as event scheduling management, manufacturing process planning, operation process/step planning, numerical control machining program planning, process simulation and evaluation, are introduced; and the methods of process knowledge management, including process feature knowledge, manufacturing resource knowledge and process method knowledge, are discussed as well. A-CAPP applied for intelligent manufacturing system can effectively support the production line reconstruction dynamically; shorten the time of production line configuration modification in accordance with customers' requirement change or market requirement fluctuation, and further more to balance the production lines load.
A model for integrating process planning and production planning and control in machining processes
2008
The goal of process planning is to propose the routing of a previously designed part and results in a sequence of operations and their parameters. It concerns and requires detailed information about the process. The goal of production planning, on the other hand, is to schedule, sequence and launch the orders introduced on the routing sheet into the job-shop according to the enterprise's strategic goal and the actual conditions of the production plant. The goals, information and decisions taken in process planning and production planning and control are often very different and, because of that, it is very difficult to integrate them.