Patent ID: 7409320

Claim:
An apparatus for monitoring the operating condition of a system, comprising: sensor means for acquiring a time-varying signal from a single sensor and characterizing operation of the system; means for decomposing said time-varying signal into a plurality of component signals, each component signal at least partially representing the same time period as all of the other component signals, the component signals providing a plurality of actual component values, at least some of the actual component values from different component signals representing the same moment in time, the plurality of actual component values forming an actual snapshot; a memory for storing a plurality of reference snapshots of component values for known operating conditions; and processor means responsive to the decomposing means, disposed to generate estimates of the component values using a similarity operation on the actual component values from the decomposing means with reference to the component values in each reference snapshot in the memory, according to: y -> expected = D · ( D T ⊗ D ) - 1 · ( D T ⊗ y -> input ) where y(input) is a vector of said plurality of actual component values y(expected) is a vector of said estimates, D is a matrix of said reference snapshots, and {circle around (x)} is said similarity operation, and wherein said processor means is further disposed to generate residual values by differencing the component values and the estimates thereof, for determination of deviating operating conditions of the system.