Patent ID: 6910156
Filing Date: 2005-06-21
Classification: G05B,Y10S

Abstract:
1. A diagnostic method for a technical installation for determining a cause of a fault event described by a fault state variable, the method which comprises: establishing an operating state of the installation defined by state variables, by determining diagnostic parameters each characterizing one of the state variables; compiling a dependency tree containing at least some of the diagnostic parameters by configuring the dependency tree with the following hierarchical levels numbered Hn, where n=1, 2, . . . : determining a fault path in the dependency tree starting from the fault diagnostic parameter, by identifying a responsible diagnostic parameter at the hierarchical level Hn+1 depending on one of a magnitude or a change direction of a diagnostic parameter at the given hierarchical level Hn; inferring a cause of the fault from the responsible diagnostic parameter identified in the identifying step at a last one of the hierarchical levels; and allocating one of a rising, a falling or a constant change direction to each diagnostic parameter at the hierarchical level Hn+1, for each diagnostic parameter at the given hierarchical level Hn, as a function of a redefined change direction of the respective diagnostic parameter at the given hierarchical level Hn, and establishing the fault path by agreement between measured change directions of the diagnostic parameters and the allocated change directions.