Use of Monte Carlo simulation to select dimensions, tolerances, and precision for automated assembly

Abstract

Abstract Design for assembly is a multifaceted problem that includes the determination of shape and size of mating parts and the selection of part production and assembly processes. An analytical method has been previously presented for selecting the dimensions and tolerances of mating parts and the precision of assembly equipment where the mating parts possess simple geometries such as lines and circles. This paper proposes a Monte Carlo modeling, simulation, and inferencing method to make the methodology applicable to the design of assemblies with irregular and complex cross sections. The method is implemented for the ellipse and convex polygon cross sections to illustrate the analytical and geometrical ideas involved. The ellipse model determines the effect of out-of-roundness on the mating of what would ideally be circular parts. The assembly performance of polygon shaped geometries is studied employing two alternative methods; fixed side ratios, and proportional clearances. Using the presented method, the noncontact and/or chamferless insertion of precision mechanical components can be analyzed and designed for high performance processing. Other applications of the method include aligning beams in material combining processes such as laser sintering, and placing a cutting edge or beam against a material in machining processes such as stamping and electrical discharge machining.