Group-Technology-Based Computer-Aided Fixture Design
Flexible fixturing is an important issue in flexible manufacturing systems (FMS) and computer-integrated manufacturing systems (CIMS). Application of modular fixtures is a solution of flexible fixturing. One major difficulty in applying modular fixtures in industry is the complexity of their design and assembly. This chapter presents a group-technology-(GT) based modu lar-fixture design method. The method is based on a fixturing structure anal ysis. Based on the analysis, it is pointed out that the locating method and part geometry dominate the fixture structure, and the surface feature analysis is a key issue in determining the locating method. Therefore, the fixturing requirement accomplished with a part design and manufacturing plan is iden tified through a fixturing feature identification scheme where the part geo metric, operational, and fixturing information are recognized. The fixturing information is represented in three levels: surfaces (machining, locatable, and clamping surfaces), surface features, and interrelationships between the surfaces. A fixturing feature extraction scheme with a flexible code structure is used to acquire the information from the part design and manufacturing plan. This scheme can be applied to a computer-aided fixture design (CAFD) system with the retrieval approach.