METHODS AND SYSTEMS TO DERIVE ENGINE COMPONENT HEALTH USING TOTAL HARMONIC DISTORTION IN A KNOCK SENSOR SIGNAL

A method 110 of deriving reciprocating device 12 component health includes receiving 114 a signal from a knock sensor coupled to a reciprocating device 12, deriving 118 total harmonic distortion (THD) at one or more frequencies, and determining 120 whether the derived THD exceeds a threshold value.