Patent ID: 7383799

Claim:
A method for monitoring a valve system of an engine, comprising the steps of: obtaining a first current magnitude of a parameter which is representative of an operating characteristic of said valve system corresponding to a first operating speed of said engine; comparing said first current magnitude to a first reference magnitude; determining an operating condition of said valve system of said engine as a function of a difference between said first current magnitude and said first reference magnitude, said first current magnitude of said parameter being determined by the step of measuring a first series of sensor output signals within a predefined window of the operational cycle of said valve system; obtaining a second current magnitude of a parameter which is representative of an operating characteristic of said valve system corresponding to a second operating speed of said engine; comparing said second current magnitude to a second reference magnitude corresponding to said second operating speed of said engine; and determining an operating condition of said valve system of said engine as a function of a difference between said second current magnitude and said second reference magnitude, said second current magnitude of said parameter being determined by the steps of; (a) measuring a second series of sensor output signals within a predefined window of the operational cycle of said valve system; (b) filtering the result of said measuring step according to a preselected range of frequencies; (c) rectifying the result of said filtering step; and (d) integrating the results of said rectifying step to obtain said second current magnitude of a parameter which is representative of an operating characteristic of said valve system.