Published online by Cambridge University Press: 27 February 2009
Fixtures are used in almost all manufacturing operations. They take on many different forms, ranging from simple mechanical vises to modular fixtures to specialized fixtures. For cylindrical parts or simple prismatic parts, automatic design of fixtures is feasible. However, for parts of irregular shape such as castings or forged parts, the automation of fixture design is a complex problem. In this paper we address the problem of fixture layout for parts of complicated shape. Issues related to automatic design such as completeness, soundness, and computing efficiency are first discussed. A theoretical framework based on algebraic formulations is developed which models human reasoning employed for workpiece restraint. These formulations will ensure the completeness and soundness of the design methodology. They also provide a mechanism for constraint propagation in the design space. Finally, the generality of the framework is discussed.