Integrating constraint-based and numerical simulation

Presents an approach to integrate qualitative simulation with the results of numerical simulators. The authors implemented a system QQSIM (quantitative and qualitative simulation) using data coming from a generic quantitative simulator to prune the state space tree generated by a QSIM-based qualitative simulator. In many engineering applications, sophisticated numerical models of systems are available to the staff to perform simulations. Interpretation of their results, their modifications, and computational resources are problems for this kind of simulators. Qualitative simulation has been proposed as an alternative, but it seems not to be problem-free in case of complex models. The proposal presented is aimed at reusing possibly available numerical simulators for some parts of a complex system, integrating their results with those produced by a constraint-based simulation of some other part of the system. The resulting global simulation merges benefits from both the approaches, providing qualitative data bounded to quantitative information, which can be easily interpreted