ISOLATING ERRORS IN MODELS OF COMPLEX-SYSTEMS

One of the steps in creating a mathematical model of a system is to te st the model after it has been fully specified, to see whether it is p erforming adequately. Often, it is found that the model is not perform ing acceptably (e.g., if the model is not giving accurate predictions of the performance of the actual system). This lack of fidelity can al so be observed in established models that had been performing well, in dicating a change in the actual system. At this point, it is necessary to diagnose where the problem in the model lies, a process called ''e rror isolation.'' We describe an error isolation technique for detecti ng the misspecified parameter (or set of parameters); this technique i s especially designed for use on state-space models of large-scale sys tems. We report on an example of an application of the methodology to localizing errors in the model of an inertial navigation system.