Design for manufacture using machining features on CNC machining centers

Computer-Aided Design (CAD) and Computer-Aided Manufacturing (CAM) systems have become more and more needed and useful in the machining processes environment. In order to achieve competitive advantage, companies adopted new manufacturing methods. As a consequence, and in machining processes context, the interaction of CAD and CAM has growth over the years in order to increase the production efficiency, as well as to reduce costs and time. The development of this work started with an extensive literature review. In that review, the author found that only a few articles approached the interaction or integration of CAD and CAM systems. Moreover, the authors that studied this interaction focused on systems for turning parts. Thus, there is a gap in the literature related to the integration and automation of these systems when applied to milling parts. Therefore, the purpose of this dissertation is to enable the interaction of these systems in order to provide a completely automated process since the design stage until the machining stage. Finally, the process’ implementation showed that the developed algorithm was able to satisfy the initial requirements of this work, i.e., when given a set of initial parameters, the program drew the required geometry, and then generated the required G-code, such that this code can be sent to the CAM software to machine the workpiece, thereby obtaining the final product.Os sistemas Computer-Aided Design (CAD) and Computer-Aided Manufacturing(CAM) estão, cada vez mais, a ser mais necessários e úteis no contexto da maquinagem. De modo a conseguir vantagem competitiva, as empresas têm adotado novos métodos de produção. Consequentemente, no contexto da indústria da maquinagem, a interação entre CAD e CAM tem crescido nos últimos anos, de modo a permitir uma maior eficácia na produção, assim como também redução de tempo e custo. O desenvolvimento deste trabalho começou com uma extensa revisão da literatura. Nesta revisão, o autor apercebeu-se que apenas alguns artigos se debruçaram sobre a interação ou integração dos sistemas CAD e CAM. Para além disso, os autores desses artigos focaram-se em sistemas para torneamento. Assim, constata-se que existe um espaço livre na literatura no que diz respeito à integração destes sistemas quando aplicados à fresagem. Por isso, o objetivo desta dissertação é permitir a interação dos dois sistemas referidos, de forma a promover um processo completamente automático desde o design até à maquinagem. Por fim, a implementação do processo mostrou que o algoritmo desenvolvido alcançou os objetivos iniciais do trabalho, ou seja, baseando-se apenas nos parâmetros fornecidos, o programa desenhou as geometrias necessárias, sendo depois capaz de gerar o código G respetivo, para que este possa ser transferido para o centro de maquinagem, de modo a que o material possa ser maquinado, dando origem ao produto final

An automated method mapping parametric features between computer aided design software

This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University LondonEnterprise efficiency is limited by data exchange. A product designer might specify the geometry of a product with a Computer Aided Design program, an engineer might re-use that geometry data to calculate physical properties of the product using a Finite Element Analysis program. These different domains place different requirements on the product representation. Representations of product data required for different tasks is dependent on the vendor software associated with those tasks, sharing data between different vendor programs is limited by incompatibility of the vendor formats used. In the case of Computer Aided Design where the virtual form of an object is modelled, no standard data format captures complete model data. Common data standards transfer model surface geometry without capturing the topological elements from which these geometries are constructed. There are prescriptive data representations to allow these features to be specified in a neutral format, but little incentive for vendors to adopt these schemes. Recent efforts instead focus on identifying similar feature elements between different vendor CAD programs, however this approach relies on onerous manual identification requiring frequent revision. This research develops methods to automate the task of mapping relationships between different data format representations. Two independent matching techniques identify similar CAD feature functions between heterogeneous programs. Text similarity and object geometry matching techniques are combined to match the data formats associated with CAD programs. An efficient search for matching function parameters is performed using a genetic algorithm that incorporates semantic data matching and geometry data matching. A greedy semantic matching algorithm is developed that compares with the Doc2vec short text matching technique over the API dataset tested. A SVD geometric surface registration technique is developed that requires fewer calculations than an equivalent Iterative Closest Point method