Subassembly Stability

Abstract

Planning a product assembly requires that we determine the order in which the product subparts are to be assembled. One constraint on this ordering is that the subassembly must be stable at each stage under the gravitational force and the insertion force of the next part to be assembled. In this paper, we discuss the stability problem for the case where the subassembly sits on a table. A program has been written to solve this problem for a class of subassemblies. The input to the program consists of a model of the subparts and their interconnections, and a set of external insertion forces. The program tests whether the total disturbance force is contained in the set of all stable forces between each subpart and the table. A linearized model of friction in six dimensions is used in the computation.