Optimal Fixture Layout Design in a Discrete Domain for 3D Workpieces

This paper addresses two major issues in fixture layout design: (1) to determine the feasible fixture configurations that satisfy fundamental requirements such as kinematic localization and total fixturing (formclosure) and (2) to evaluate the acceptable fixture designs on several quality criteria and select the optimal fixture appropriate with practical demands. The performance objectives considered include the workpiece localization accuracy, and the norm and distribution of the locator contact forces. An efficient automated tool based on an interchange algorithm is developed for designing optimal fixture layout for arbitrary 3D parts. A thorough analysis is performed on the fixture characteristics during the single and multiple-criteria optimization process for different frequent cases, and on the inter-relationship between locators and clamps, leading to conclusions and strategies for performing fixture synthesis.