Method, computer program, and system for intrinsic timescale decomposition, filtering, and automated analysis of signals of arbitrary origin or timescale

• US 7,401,008 B2
• Filed: 05/01/2006
• Issued: 07/15/2008
• Est. Priority Date: 10/11/2002
• Status: Expired due to Term

• Current Assignee: Ivan Osorio, Mark G. Frei
• Original Assignee: Ivan Osorio, Mark G. Frei
• Inventors: Frei, Mark G., Osorio, Ivan
• Primary Examiner(s): Wachsman; Hal D
• Application Number:
  US11/415,064
• Publication Number:
  US 20070030002A1
• Time in Patent Office: 806 Days
• Field of Search: 702/190, 702/70, 702/74, 702/72
• US Class Current: 702/190
• CPC Class Codes: G05B 23/0221 Preprocessing measurements, e.g. data collection rate adjustment; Standardization of measurements; Time series or signal analysis, e.g. frequency analysis or wavelets; Trustworthiness of measurements; Indexes therefor; Measurements using easily measured parameters to estimate parameters difficult to measure; Virtual sensor creation; De-noising; Sensor fusion; Unconventional preprocessing inherently present in specific fault detection methods like PCA-based methods
• CPC Class Codes: G06F 17/14 Fourier, Walsh or analogous domain transformations , e.g. Laplace, Hilbert, Karhunen-Loeve, transforms for correlation function computation G06F17/156; spectrum analysers G01R23/16
• CPC Class Codes: G06F 2218/02 Preprocessing
• CPC Class Codes: G06F 2218/08 Feature extraction

Abstract

A method and system for intrinsic timescale decomposition, filtering, and automated analysis of signals of arbitrary origin or timescale including receiving an input signal, determining a baseline segment and a monotonic residual segment with strictly negative minimum and strictly positive maximum between two successive extrema of the input signal, and producing a baseline output signal and a residual output signal. The method and system also includes determining at least one instantaneous frequency estimate from a proper rotation signal, determining a zero-crossing and a local extremum of the proper rotation signal, and applying interpolation thereto to determine an instantaneous frequency estimate thereof. The method and system further includes determining at least one instantaneous frequency estimate from a proper rotation signal, extracting an amplitude-normalized half wave therefrom and applying an arcsine function to the amplitude-normalized half wave to determine an instantaneous frequency estimate of the proper rotation signal.

Claims

1. A method of determining at least one instantaneous phase angle estimate at a selected time from a proper rotation signal, including the steps of:

(a) inputting the proper rotation signal to a processor;

(b) extracting an amplitude-normalized half wave of the proper rotation signal wherein the extracted amplitude-normalized half wave includes start and end times and a local extremum having well-defined phase angles, the extracted amplitude-normalized half wave having a value at the selected time; and

(c) determining the at least one instantaneous phase angle estimate of the extracted amplitude-normalized half wave at the selected time by obtaining a data point from a linear interpolation spanning the start and end times and the local extremum, the abscissa of the data point being equal to the value of the amplitude-normalized half wave at the selected time and the at least one instantaneous phase angle estimate being provided by the ordinate of the data point.

2. A method of determining at least one instantaneous phase angle estimate at a selected time from a proper rotation signal, including the steps of:

(a) inputting the proper rotation signal to a processor;

(b) extracting an amplitude-normalized half wave from the proper rotation signal wherein the extracted amplitude-normalized half wave includes start and end times having well-defined phase angles;

(c) determining a value of the extracted amplitude-normalized half wave at the selected time;

(d) determining an arcsine of said value; and

(e) determining the at least one instantaneous phase angle estimate by adding or subtracting the arcsine of said value to one of the well-defined phase angles at the start or end time of the extracted amplitude-normalized half wave.

3. A method of determining an instantaneous amplitude estimate at a selected time from a proper rotation signal, including the steps of:

(a) inputting the proper rotation signal to a processor;

(b) determining a zero-crossing and a local extremum of the proper rotation signal, wherein the selected time lies between the zero-crossing and the local extremum; and

(c) determining the instantaneous amplitude estimate at the selected time wherein the instantaneous amplitude estimate is provided by a value of the proper rotation signal at the local extremum.

4. A method of determining at least one time-frequency-energy information feature at a selected time from a signal, comprising the steps of:

(a) decomposing the signal into a set of one or more proper rotation signals and a residual baseline trend signal;

(b) determining at least one zero-crossing and a local extremum adjacent thereto for the at least one proper rotation signal of the set of one or more proper rotation signals wherein the selected time lies between the at least one zero-crossing and the adjacent local extremum; and

(c) determining the at least one time-frequency-energy information feature of the at least one proper rotation signal of the set of one or more proper rotation signals at the selected time, wherein the at least one time-frequency-energy information feature is selected from the group comprising an instantaneous amplitude estimate, an instantaneous energy estimate, an instantaneous phase angle estimate, and an instantaneous frequency estimate.