A constraint approach to feature-based design

Abstract

Abstract A general approach to the use of features has shown that various different definitions can be created dependent upon the goals set. Within both design and manufacturing two distinct types can be established. Functional features allow higher levels of abstraction whilst geometric form features allow for rationalization. Within the manufacturing environment a similar division leads lo features defined in terms of process operations and those based on the geometric operations being executed, here termed manufacturing motion features (MMFs). An investigation into the communications between CAD systems and coordinate measuring machines has led to the adoption of MMFs to allow errors in manufacturing to be detected. This employs a constraint modelling approach in which the truth of the tolerance condition of the part is established. Through the investigation of errors, scenarios arc proposed and tested by the constraint modeller and both the causes and corrective actions determined.