Some Applications of Artificial Intelligence Techniques to Automatic Tolerance Analysis and Synthesis

Since no mechanical part can be manufactured with exact dimensions and perfect shape, tolerances, together with dimensions, are used to specify acceptable variations of part geometry. To ensure design functionality, assemblability and manufacturability, tolerances must be specified and checked. Currently, dimensions and tolerances are usually placed on design drawings of CAD systems in accordance with ANSI [1], ISO [2] or other national standards. Tolerance analysis is used to check the stack-up of related tolerances. The process of tolerance accumulation is modelled, and the accumulated tolerance is verified. Tolerance synthesis (or tolerance design), on the other hand, is the process of allocating tolerance values derived from design requirements in terms of functionality or assemblability among related design tolerances. It is a process of distributing a few known tolerance values.