Robust pin layout design for sheet-panel locating

Sheet panels, represented as freeform surfaces in a CAD system, are widely used in manufacturing processes. Locating blocks and pins, collectively known as locators, are the most common fixtures for the joining and assembly of sheet panels. In this paper, a robust design approach is utilized to optimize the pin layout so that the sheet panel variations, expressed as translational and orientational variations at certain key product/process characteristic points (KPCs), are minimized. The advantage of this approach is that the locating variations at any given point on the panel can be obtained quantitatively, and hence, the optimal pin design can be selected from among an infinite set of feasible designs. Based on the analyses, some useful pin design guidelines will also be proposed.