An integrated Process Planning and Robust Fixture Design System

Abstract

This research addresses the development of an integrated process planning and robust fixture design system. Integrative features, i.e., machining features, fixturing features, set-up features and machine resource features, are used to integrate the set-up planning, machining resource planning and fixture planning from product conceptualization to optimizing the product and its manufacturing processes simultaneously to meet cost and performance objectives. A hybrid fixturing-feature-based approach is presented to obtain the fixturing features. The developed ACO-based process planning system considers the selection of available machine tools, tolerance analysis and cost modeling simultaneously for achieving optimal set-up planning. A tolerance cost factor is introduced when machining error stack-up occurs. The developed robust fixture design approach treats a fixture layout as a multi-objective optimization problem which considers both the mean localization error and the variation of the mean localization error of the machining features in a set-up as well as the location stability and reliability. Non-dominated ACO and GA are presented to solve this multi-objective problem and the solutions are compared.