Functional proposal and information and knowledge structure proposal for computer-aided process planning. Application to processes, operations and machines selection for mechanical parts (Spanish text).

摘要

The objective of this PhD work is the study of computer aided processes planning systems, known as CAPP. These systems play an important roll in the Computer Integrated Manufacture (CIM). They bridge design (CAD) and others Computer Aided Manufacturing (CAM) applications.; The low current development of these CAPP applications have caused for a lake in the function that develop and in the integration of the manufacturing systems. Nowadays do not exist these kind of applications available for the industry.; The development of CAPP systems have special interest in the machining processes domain due to the complexity that implies the processes planning, the great presence in the most final stages of the part manufacture and the integration with a great number of CAM applications for machining. Because of this, the development field selected was the machining processes, including also thermal treatment and finished processes such as cleaning, surface coating, etc.; In this thesis it is proposed a way to develop these kind of systems, that make possible their generality respect to the product and productive resources and their flexibility respect to continuous variations to those which are submitted the manufacture environments.; From the beginning has been selected a generative strategy that permits the automatic process plans generation, being focuses in the functions involved in macro plan. Concretely the objectives are the selection of processes, operations and the phases sequencing.; It has been proposed a problem resolution methodology that permits the integration with the rest of manufacture processes and production areas functions. Furthermore it satisfies the flexibility and generality objectives respect to the product and productive resources. At the same time it has been proposed a detailed functional model that specifies the different functions needed as well as the relationships between them.; The information system is one of the keys in the standardisation of CAPP systems, and it should be able to represent any part and different productive resources. At this point, we make a proposal whose principal quality is the generality. This proposal has been accomplished for the necessary information structures in the assignment and treatment of processes, operations and machines. From another point of view, with these information structures is proposed a generic model of these productive resources for processes planning.; Also a proposal of the functional procedures for the most important functions of the system has been accomplished, all of them designed with a great generality. A special attention has been made about the necessary knowledge that allows these functions to solve the problem. The studied functions are: processes and operations assignment, compatibly of alternative operations, selection of machines, determination of precedence relations and phases (machines) sequencing.; A prototype has been implemented in order to prove and guaranty in a global way the good behaviour of: the planning method, the functional model, the information model and the functional procedures. The results has been successful and shows that the proposal can solve any type of part and can be applied to different manufacture environments.