A signal pattern matching and verification method using interval means cross correlation and eigenvalues in the nuclear power plant monitoring systems

Monitoring signals in the control room of nuclear power plants come in through multiple channels and are displayed as graphs on the display devices. It is crucial to make correct and reliable decisions on the relationships among the graphs, which are representations of signals from different channels, both by implemented algorithms and human decisions. Simplified schemes to compare signal envelopes using cross correlation and cross entropy are introduced. In this work, algorithms to curve-fit the signal envelope to a polynomial and envelope generation with interval means are also researched. When generating signal envelopes, using interval means instead of interval medians is safe enough and is not seriously influenced by possible outliers. An effective use of eigenvalues for verification of the signal correlation is pursued in this work for a three channel case.