Method and apparatus for utilizing microwaves for internal combustion engine diagnostics

摘要

A method and apparatus is disclosed for determining various diagnostic conditions of an internal combustion engine from an analysis of the resonances of a reflected microwave signal radiated into a combustion chamber of the internal combustion engine. Various parameters of each microwave resonance are calculated including: (1) the location of the resonance with respect to the crank angle of a crankshaft of the engine; (2) the peak-to-peak amplitude of the resonance; (3) the slope of the resonance; (4) the quality factor or "Q" of the resonance; and (5) the symmetry of parameters 1 through 4 with respect to turnaround points of the piston in the cylinder of the engine. The calculated parameters are thereafter correlated with reference parameters to determine the particular diagnostic condition.