Development of the computer-aided process planning (CAPP) system for polymer injection molds manufacturing

Beginning of production and selling of polymer products largely depends on mold manufacturing. The costs of mold manufacturing have significant share in the final price of a product. The best way to improve and rationalize polymer injection molds production process is by doing mold design automation and manufacturing process planning automation. This paper reviews development of a dedicated process planning system for manufacturing of the mold for injection molding, which integrates computer-aided design (CAD), computer-aided process planning (CAPP) and computer-aided manufacturing (CAM) technologies

Feature based computer aided process planning

This research attempts to study, plan and develop an integrated feature based CAPP system that generates automated process plans for machining prismatic components. The CAPP system comprises a STEP compliant feature based commercial CAD system and the Smalltalk object oriented system. A library of features has been developed that is based on STEP based form feature taxonomy but modified to communicate the manufacturing intent and feature aggregation. The CAPP system has been developed to represent the product, process and resource domain knowledge with a number of object hierarchies, communication methods, and the user interface that would suit the concurrent engineering needs. In addition, suitable geometric and process reasoning methods have been developed in the CAPP system that use the feature based component design data to generate automated process plans. The research also attempts to identify the problems in feature based process planning and discusses the possible solutions. A solution to the side feature interaction problem has been implemented in the CAPP system. The CAPP system test results have demonstrated that the proposed approach has been successful and has a great potential for further improvements in terms of flexibility, modularity, emerging data exchange standards, and case in customising the CAPP system

Development of a classification and coding system for computer-aided process planning

The chore of this work was to develop a Group Technology Classification Code which can represent the full gamut of simple, rotational parts. The automated coding plan is developed to alleviate the endeavor of the process planner to plan the tasks related to the manufacturing of a specific part. The 15 digits were devised from the Japanese KK-3 Classification and Coding system. The KK-3 System contains 21 digits. Our aim is to minimize the code length, and concurrently to eliminate the redundancies. As a result, a 15 digit G.T. Code is created. The proposed plan also generates the operation logic with the aid of the 15 digit G. I Code and the machines available in the database of the system. The program is designed to run on vax/vms 5.1. The program for the work has been written in Fortran - 77

Development Of Generative Computer-Aided Process Planning System For Lathe Machining

Computer Aided Process Planning (CAPP) is the bridge between computer-aided design (CAD) and computer-aided manufacturing (CAM). CAPP functions as the recognizer of the geometric input from CAD and analyse it into specific function for manufacturing purpose in CAM. These functions always create irregular data descriptions in current CAD and CAM system supply and demand. This study attempts to solve this problem by recognizing the part model’s features via its geometrical based and produce sub-delta volumes that can later be used to generate manufacturing feature-based data for CAM in a single system via generations of algorithm through open source 3D CAD modeller. To map the generated sub-delta volume and respective machining process, part model complexity (PMC) is introduced. Errors of the overall delta volume (ΔODV) were calculated and verification of the proposed PMC is done. Furthermore, to minimize unit production cost, machining parameters including cutting speed (CS), feed rate (f) and depth of cut (d) were optimized for regular form surfaces by using firefly algorithm (FA). These parameters were then useful for tooling selections and tool-path planning. The results from the automatic feature recognitions show less than 0.02% of error in comparison of algorithm overall delta volume, (ODValg) and the manual calculation ODV, (ODVmanual). To validate the generated tool-path, G-codes generated in media package file (MPF) file format and verified through CNC lathe machine. Indeed, the developed algorithm was able to determine the minimum unit production cost of lathe machining part model. Therefore, a single automatic system that able to transfer CAD data into machining readable data through CAM data had been developed

COMPUTER-AIDED FIXTURE PLANNING: A REVIEW

Fixture planning is a complex activity restricted by the extreme diversity of workpieces and constraints of design geometry, part accessibility, working force, and component deformation. This paper reviews major approaches to computer-aided fixture planning (CAFP). Geometry methods, kinematical analysis, force analysis, deformation analysis, case-base reasoning, fixture assembly planning, feature-based methods, rule-based methods and optimization methods are surveyed. The CAFP systems are summarized as CAD-based systems and Web-based systems. Some promising research areas are identified in respect of fixture design, assembly planning and virtual fixture planning

A microworld model for multiagent computer-aided process planning.

This Thesis proposes and investigates a novel framework for the study of multiagent solutions for computer-aided process planning (CAPP) in manufacturing systems. The framework is based on a domain-specific microworld model of CAPP, called the CAPP World. The motivation comes from the current literature on multiagent systems (MAS) for CAPP, which emphasized the need for comparative studies that would identify the most suitable domain-specific multiagent solutions, and from the observation that a simple, manageable framework for such studies had not been developed. The proposed CAPP World is characterized by a product class, a model of a manufacturing cell, and appropriate adaptation and simplification of CAPP modeling concepts from the literature. These abstractions lead to a collection of specific actions that jointly construct a process plan in CAPP World. The analysis shows that the model meets its design objectives of being: simple integral in the sense of including the main aspects of CAPP representative of properties and difficulties in real-world CAPP and suitable for formulation and investigation of MAS solutions for CAPP. The suitability of CAPP World for domain-specific MAS studies is demonstrated through construction of concrete scenarios addressing topics such as: agent encapsulation, cooperation and coordination among team members, cooperative iterative improvements of process plan, improving the efficiency of process planning through caching of design solutions, team composition, and communication mechanisms. The Thesis also identifies some topics for future research. --P.[i]The original print copy of this thesis may be available here: http://wizard.unbc.ca/record=b164402

Activity model and computer aided system for defining sheet metal process planning

This paper focuses on the problem of choosing the manufacturing route and characteristics in sheet metal processes, a very important element in computer aided process planning (CAPP) systems. At present, decisions concerning the operations, die, machine and process parameters used in sheet metal are based on experience. One of the objectives of this work has been to develop an activity model to help define sheet metal processes. This activity model allows focusing on the second objective, which is to implement a computer aided system to select and define the parameters of the process definition in the case of drawing operations with sheet metal. The result is the selection of parameters related to the operations chosen, the kinds of operations, the sequence of these operations and the lay-out die dimensions for the product. A range of parts were evaluated. They were chosen because they were considered to be representative cases. The results obtained by the system are compared with the values proposed in reference manuals, and by experienced experts. The work has served to determine how to adjust the computer aided system. Applying the method helps to make the right decisions about the sheet metal operations related to drawing processes. The experiments have led to a reduction in processing times

Computer aided process planning for rapid prototyping using a genetic algorithm

This thesis presents a new method for Computer Aided Process Planning (CAPP) for a subtractive Rapid Prototyping (RP) process. The CNC-RP process uses a 4-axis CNC machining center to create parts with flat end-mills. The objective is to determine the optimal system parameters for the RP process - those that enable parts to be created in a shorter amount of time. Two main contributions make this possible. First, a method of generating different machining orientation sets enables the part to be created with the same level of safety and quality available with the current system. Second, machining time is related to tool selection. These two contributions are combined into a single objective function. A Genetic Algorithm technique is implemented to determine the best machining tool sizes and machining orientations. The results show that a Genetic Algorithm can be applied to a RP process plan to reduce the total processing time

Computer Aided Inspection Planning For Automation Of On-Machine Inspection Of Customised Milling Parts

Customised products force manufacturing systems to operate efficient at batch size one. Automation in upstream processes and on shop floor increase productivity. Besides value-adding processes, quality management to sustain product quality must be considered regarding automation and consistency from 3D model to the execution on shop floor. Computer aided inspection planning addresses the automation of measurement operations. The inspection planning starts with a customised 3D model and realises a simple execution of the measurement task on shop floor level. A method for implementation of computer-aided inspection planning for tactile on-machine inspection will be presented to realise potentials like tool deviation and work piece correction based on measurement results. The developed method focuses on ensuring automation of computer aided inspection planning and sets up the basis for a self-controlling manufacturing system of customised milling parts. A validation was performed at a manufacturing company for customised drilling tools and enabled less downtime and rework time for milling machines