HIERARCHICAL RESTRUCTURING, GENERIC TEST TEMPLATES, AND REUSABLE VALUE SPACES FOR MACHINE FAILURE ISOLATION USING QUALITATIVE PHYSICS

The presence of particular faults in a machine is determined using constraint suspension and Qualitative Physics by propagating values indicative of received machine signals through a subset of model variables that are either unrestricted or partially restricted. The implicants of each value assigned to a variable of the subset of variables can be determined and other variables can be restricted according to the union of the implicants. Values for fully restricted and partially restricted variables can be propagated in order to further restrict any other variables. The values of variables can be either qualitative, quantitative, or both. A Qualitative Physics model of a machine can be constructed by providing a user with a graphical user interface allowing selection and interconnection of machine components for the model such that the user can define a landmark domain and apply the landmark domain to provide definitions of qualitative value spaces of variables of the model.