| Abstract: | One of the important steps of process planning is to determine the tolerance and mean size for each working dimension. This paper presents a computer-aided operational diminsioning systems which can determine tolerances systematically and calculate mean sizes of working dimensions automatically for a process plan. The system is based on the tolerance charting technique. Firstly, a tree theoretic representation for a tolerance chart is described in this paper. Three trees can be generated from blue print dimensions, stock removals and working dimensions of a tolerance chart. The algorithms for generating the trees are provided, and these trees can be used to identify dimensional chains and solid stock removals in a tolerance chart. Then a linear programming model is built to determine the tolerance of each working dimension. Finally, a mathematical model of linear equations for calculating mean working dimensions is formulated from the dimensional chains. |
