An extendible computer-aided process planning (CAPP) system for turn-milled components.
| dc.contributor.author | Mwinuka, Tito Esau | |
| dc.date.accessioned | 2020-01-16T09:43:28Z | |
| dc.date.available | 2020-01-16T09:43:28Z | |
| dc.date.issued | 2006 | |
| dc.description | Available in print form, East Africana Collection, Dr. Wilbert Chagula Library, Class mark (THS EAF TS155.6M95) | en_US |
| dc.description.abstract | This thesis presents results of a research on an extendible Computer-Aided Process Planning (CAPP) system for turn-milled components. The research was motivated by the shortcomings of the current CAPP systems which have been identified to be rigidity and low level of automation and the fact that the utilization of CAPP system in industry is very much lagging behind other computer-aided systems like Computer-Aided Design and Computer-Aided Manufacturing. The objective of the research was to develop a CAPP system which a user can extend to cope with the changes occurring in manufacturing environment like changes products and their features, tool materials, status of manufacturing resources, process technology and process planning knowledge without doing any additional programming. Few CAPP systems which have been found to address extendibility, have dealt with the issue in a very limited context with lack of integration. The most commonly reported approach towards achieving extendible systems is the use of artificial intelligence (knowledge based system or expert systems). However expert system shells in use have been reported to have limitation in strength especially in knowledge acquisition and in performing some functions including mathematical computations. Also an object oriented approach has been reported, whereby process planning entities can be modeled in object classes, which encapsulate data and knowledge for using the data. New child classes can be created that inherits attributes of their parent classes. However this approach needs object oriented programming skills. In this work extendibility is achieved by separating data and knowledge from program routines that are more generic rather than hard coded. Intersecting feature volumes, which do not impose any removal sequence, have been used to represent a machined component. This work is novel because: (i) it has explored extendibility in a wider CAPP context without the need for additional programming; (ii) it has achieved dynamic integration between available operations, feature removal processes and existing resources; (iii) it has developed and tested a robust technique for construction of intersecting volumes of machining features; (iv) it has considered deflection of spindle-chuck-bearing of a machine tool system and changes in stiffness of a workpiece during machining in optimizing cutting parameters; (v) it has applied extendible and flexible set of constraints in selection of machine tools; (vi) it has developed a procedure for quantifying the effect of feature removal on residual stiffness of a work piece and consequently it has quantitatively applied this effect in sequencing of machining operations, and (vii) it has flexibly combined the maximization of stiffness criterion, cost-based precedence relationships between intersecting features and user-defined extendible heuristic rules for sequencing of machining operations. Automation has been achieved to a reasonable extent. The system can produce an operation plan of a component from its 3D CAD solid model. Implementation is done in a PC using the Visual C++ programming language. Also ACIS, which is a geometric modeling kernel, has been used for geometric reasoning. The system has moments with both ax symmetric and non-ax symmetric features from been tested on CAPP two manufacturing companies. Future work includes automation of machining feature recognition, increasing the level of automation in process planning and addition of production scheduling capabilities. | en_US |
| dc.identifier.citation | Mwinuka, T. E (2006) An extendible computer-aided process planning (CAPP) system for turn-milled components, Master dissertation, University of Dar es Salaam. Dar es Salaam. | en_US |
| dc.identifier.uri | http://41.86.178.5:8080/xmlui/handle/123456789/6534 | |
| dc.language.iso | en | en_US |
| dc.publisher | University of Dar es Salaam | en_US |
| dc.subject | Computer-Aided Process Planning | en_US |
| dc.subject | Manufacturing process | en_US |
| dc.subject | Planning | en_US |
| dc.subject | Data processing | en_US |
| dc.subject | Computer integrated manufacturing systems | en_US |
| dc.subject | Computer-aided design | en_US |
| dc.title | An extendible computer-aided process planning (CAPP) system for turn-milled components. | en_US |
| dc.type | Thesis | en_US |