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

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

Development of an System for Simultaneously Product and Process Planning Design

U okviru istraživanja na predmetnoj disertaciji prikazana je analiza stanja i pravci razvoja u oblasti simultanog projektovanja proizvoda i tehnoloških procesa. Detaljnije su opisane tehnike CAD/CAPP integracije na bazi tehnoloških tipskih formi i vještačke inteligencije. Na bazi ovih analiza razvijen je model simultanog projektovanja proizvoda i tehnoloških procesa. Na osnovu modela sistema, razvijen je programski sistem za simultano projektovanje proizvoda i tehnoloških procesa. Prikazani su rezultati primjene razvijenog sistema na primjeru hidraulične prese za ugaono savijanje lima, kao proizvoda, i hidrauličnog cilindra, kao dijela proizvoda. Disertacija obuhvata i moguće pravce budućeg istraživanja.The research in this dissertation encompassed state-of-the-art and future development in the field of simultaneously product and process planning design. Technics of CAD/CAPP integration based at manufacturing features and artificial intelligence are described in detail. Based on this analysis it was developed a model of simultaneously product and process planning design. Based on this model, program system for simultaneously product and process planning design was developed. Case studies were presented at the example of hydraulics press brake for sheet metal bending, as products, and hydraulics cylinder, as part of the product. In dissertation it was also suggested directions of future investigation in this field