Methods and systems to derive engine component health using total harmonic distortion in a knock sensor signal

Patent metadata

Field	Value
Publication number	US-2016238478-A1
Application number	US-201514621028-A
Country	US
Kind code	A1
Filing date	Feb 12, 2015
Priority date	Feb 12, 2015
Publication date	Aug 18, 2016
Grant date	—

Abstract

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

First claim

1 . A method of deriving reciprocating device component health comprising:
utilizing a controller for:
receiving a signal from a knock sensor coupled to a reciprocating device;
deriving total harmonic distortion (THD) at one or more frequencies; and
determining whether the derived THD exceeds a threshold value.

2 . The method of claim 1 , further comprising obtaining the one or more frequencies.

3 . The method of claim 2 , wherein each of the one or more frequencies corresponds to a fundamental frequency of a reciprocating device component.

4 . The method of claim 1 , further comprising obtaining the threshold value.

5 . The method of claim 1 , further comprising amplifying the signal, via an amplifier, such that signal clipping does not occur under normal excitation, but signal clipping does occur under abnormal excitation, wherein abnormal excitation corresponds to a reciprocating device component wearing out or nearing failure.

6 . The method of claim 5 , wherein the amplifier is hardware-based.

7 . The method of claim 5 , wherein the amplifier is software-based.

8 . The method of claim 1 , wherein deriving the THD comprises calculating THD plus noise (THD+N) at the one or more frequencies.

9 . The method of claim 1 , wherein deriving total harmonic distortion comprises evaluating an amplitude of the signal at frequencies comprising one-fourth, one-third, one-half, second, third, and fourth harmonic frequencies.

10 . The method of claim 1 , further comprising providing a user perceptible indication of the THD exceeding the threshold value.

11 . A system comprising:
a reciprocating device controller configured to control a reciprocating device, wherein the reciprocating device controller comprises a processor configured to:
obtain one or more frequencies, wherein each of the one or more frequencies corresponds to the fundamental frequency of a reciprocating device component;
receive a signal from a knock sensor coupled to a reciprocating device;
derive total harmonic distortion (THD) at the one or more frequencies; and
determine whether the derived THD exceeds a threshold value.

12 . The system of claim 11 , wherein the reciprocating device controller further comprises an amplifier configured to amplify the signal.

13 . The system of claim 11 , wherein the amplifier is further configured to amplify the signal such that signal clipping does not occur under normal excitation, but signal clipping does occur under abnormal excitation, wherein abnormal excitation corresponds to the one or more reciprocating device components wearing out or nearing failure.

14 . The system of claim 11 , wherein deriving the THD comprises calculating the THD plus noise (THD+N) at the one or more frequencies.

15 . The system of claim 11 , wherein the processor is further configured to obtain the threshold value.

16 . The system of claim 11 , wherein deriving the THD comprises evaluating an amplitude of the signal at the one or more reciprocating device components' one-fourth, one-third, one-half, second, third, and fourth harmonic frequencies.

17 . A non-transitory computer readable medium comprising executable instructions that when executed cause a processor to:
obtain one or more frequencies, wherein each of the one or more frequencies corresponds to the fundamental frequency of a reciprocating device component; receive a signal from a knock sensor coupled to a reciprocating device; derive total harmonic distortion (THD) at the one or more frequencies; determine whether the derived THD exceeds a threshold value; and provide a user perceptible indication of the presence of distortion.

18 . The non-transitory computer readable of claim 17 , wherein deriving the THD total harmonic distortion comprises evaluating an amplitude of the signal at the one or more reciprocating device components' one-fourth, one-third, one-half, second, third, and fourth harmonic frequencies.

19 . The non-transitory computer readable of claim 17 , wherein the processor is further configured to amplify the signal such that signal clipping does not occur under normal excitation, but signal clipping does occur under abnormal excitation, wherein abnormal excitation corresponds to a reciprocating device component wearing out or nearing failure.

20 . The non-transitory computer readable of claim 17 , wherein deriving the THD comprises calculating the THD plus noise (THD+N) at the one or more frequencies.

Assignees

• Gen Electric

Inventors

• Bizub Jeffrey Jacob

Classifications

• F02F3/00

  Pistons · CPC title

• G01M15/12 Primary

  by monitoring vibrations · CPC title

• F02B77/08 Primary

  Safety, indicating, or supervising devices (thermal insulation F02B77/11; monitoring or diagnostic devices for exhaust-gas treatment apparatus F01N11/00) · CPC title

• F04B53/14

  Pistons, piston-rods or piston-rod connections · CPC title

• F02D35/027

  using knock sensors · CPC title