Determining model accuracy as a function of inputs and system parameters

Abstract

Vital to the effectiveness of simulation-based design is having a system model of known quality. Previous research introduced an algorithm called AVASIM for assessing model validity systematically and quantitatively. AVASIM assess the accuracy and validity of a model based on a specific input and set of system parameters. The purpose of this paper is to present a AVASIM-based methodology that defines a range of validity of a model with respect to input and system parameter variations Two illustrative examples are presented to explore the feasibility of the proposed procedure. The first example analyzes a linearized version of a nonlinear transient vehicle-handling model. This model's accuracy and validity are evaluated with respect to variation of two system parameters, resulting in a two-dimensional range of validity. Then a complex nonlinear hydrogen fuel cell model is linearized in order to investigate its accuracy and validity with respect to two input parameters. This again results in a two-dimensional range of validity, but with respect to input rather than system parameters. The results agree well with what is expected for the various models based on knowledge of the effects of linearization on model accuracy. The proposed algorithm for assessing model range of validity is a promising tool for determining model quality and thus potentially useful for simulation-based design. Copyright © 2004 by ASME.