Patent ID: 9217662
Filing Date: 2015-12-22
Classification: G01H

Abstract:
1. A system for compensating a vibration signal from a vibration sensor on a turbomachine, the system comprising: a low pass filter connected to the vibration sensor to filter the vibration signal; a test signal generator for calibrating the signal conditioner, wherein the test signal generator generates a test signal having a base frequency and a modulation frequency; a matching filter connected to the test signal generator to filter the test signal, the matching filter having gain and phase characteristics selected to match signal patch characteristics of the test signal with those of the filtered vibration signal; a signal conditioner to condition the filtered vibration signal, wherein the signal conditioner introduces a phase error into the vibration signal, and comprises an integrator to generate an integrated test signal, and wherein the signal conditioner introduces a phase shift into the filtered test signal; and a processor to compensate the phase error introduced by the signal conditioner by correcting the vibration signal based on the phase shift in the test signal, wherein the processor determines the phase shift in the test signal using a harmonic analysis based on the modulation frequency; wherein the test signal is a pulse width modulated square wave with a modulated pulse width at the base frequency, wherein an amplitude of the integrated test signal varies with the modulated pulse width, and wherein a period of the integrated test signal varies based on the modulation frequency.