Closed-loop analysis in semantic tolerance modeling

A semantic tolerance modeling scheme based on generalized intervals was recently proposed to allow for embedding more tolerancing intents in specifications with a combination of numerical intervals and logical quantifiers. By differentiating a priori and a posteriori tolerances, the logic relationships among variables can be interpreted, which is useful to verify completeness and soundness of numerical estimations in tolerance analysis. In this paper we present a semantic tolerance analysis approach to estimate size and geometric tolerance stackups based on closed loops of interval vectors. An interpretable linear system solver is constructed to ensure interpretability of numerical results. A direct linearization method for nonlinear systems is also developed. This new approach enhances traditional numerical analysis methods by preserving logical information during computation such that more semantics can be derived from variation estimations.