Apparatus and method for analyzing periodic motions in machinery

• US 10,459,615 B2
• Filed: 12/09/2015
• Issued: 10/29/2019
• Est. Priority Date: 12/11/2014
• Status: Active Grant

• Current Assignee: RDI Technologies, Inc.
• Original Assignee: RDI Technologies, Inc.
• Inventors: Hay, Jeffrey R.
• Primary Examiner(s): Chu, Randolph I
• Application Number:
  US14/757,245
• Publication Number:
  US 20160217587A1
• Time in Patent Office: 1,420 Days
• Field of Search: None
• CPC Class Codes: A61B 5/0077 Devices for viewing the surface of the body, e.g. camera, magnifying lens
• CPC Class Codes: A61B 5/01 Measuring temperature of body parts ; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue clinical contact thermometers G01K13/20
• CPC Class Codes: A61B 5/024 Detecting, measuring or recording pulse rate or heart rate A61B5/0205, A61B5/021 take precedence
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/165 Evaluating the state of mind, e.g. depression, anxiety
• CPC Class Codes: A61B 5/4815 Sleep quality
• CPC Class Codes: A61B 5/7435 Displaying user selection data, e.g. icons in a graphical user interface
• CPC Class Codes: G01N 2291/028 Material parameters
• CPC Class Codes: G01N 29/44 Processing the detected response signal , e.g. electronic circuits specially adapted therefor digital signal processing per se G06F17/00
• CPC Class Codes: G06F 16/7335 Graphical querying, e.g. query-by-region, query-by-sketch, query-by-trajectory, GUIs for designating a person/face/object as a query predicate end-user interface involving hot spots associated with the video H04N21/4725; end-user interface for selecting a Region of Interest H04N21/4728
• CPC Class Codes: G06F 3/04847 Interaction techniques to control parameter settings, e.g. interaction with sliders or dials
• CPC Class Codes: G06T 2200/24 involving graphical user interfaces [GUIs]
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 2207/20056 Discrete and fast Fourier transform, [DFT, FFT]
• CPC Class Codes: G06T 2207/20216 Image averaging
• CPC Class Codes: G06T 2207/30004 Biomedical image processing
• CPC Class Codes: G06T 2207/30164 Workpiece; Machine component
• CPC Class Codes: G06T 7/0016 involving temporal comparison
• CPC Class Codes: G06T 7/11 Region-based segmentation
• CPC Class Codes: G06T 7/248 involving reference images or patches
• CPC Class Codes: G06T 7/262 : using transform domain methods, e.g. Fourier domain methods
• CPC Class Codes: G06V 20/52 : Surveillance or monitoring of activities, e.g. for recognising suspicious objects recognising microscopic objects G06V20/69
• CPC Class Codes: G06V 40/20 : Movements or behaviour, e.g. gesture recognition recognition of facial expressions G06V40/16
• CPC Class Codes: H04N 7/18 : Closed-circuit television [CCTV] systems, i.e. systems in which the video signal is not broadcast

Abstract

An apparatus for monitoring machine components includes:

• • a device for acquiring video image files;
  • a data analysis system including processor and memory;
  • a computer program operating in said processor to identify an area in said images where periodic movements associated with a mechanical vibration may be detected and quantified using an adaptive array comparison procedure; and,
  • an interface to output said vibration information in a usable form.

The apparatus may further include a graphical user interface and an accessible database. An associated method for using the apparatus is also disclosed.

Claims

1. A method for monitoring an object, comprising:

acquiring a video file of the object as a sequence of video images comprising individual image frames, wherein each image frame is divided into pixels defined by spatial coordinates within the frame, and wherein brightness within each pixel is characterized with numerical values;

selecting at least two image frames acquired at different times and containing the object, a first such image frame being designated as a reference frame and at least one other image frame being designated as a differenced frame;

comparing the reference frame to the differenced frame by determining a variation in brightness based on differences in numerical values between at least one corresponding pixel having the same spatial coordinates in each of the two image frames, in which the variation indicates movement of the object;

amplifying the differences in numerical values between the two image frames by multiplying the difference by a predetermined factor to at least one amplified differenced frame;

creating at least one new image frame by superimposing the at least one amplified differenced frame onto the reference frame; and

displaying the at least one new image frame.

2. The method of claim 1, further comprising setting a frame rate for acquiring the video file by adjusting a temporal length of each image frame based on a frequency of periodic vibrations.

3. The method of claim 2, wherein a plurality of image frames are displayed as a sequence of new image video frames.

4. The method of claim 1, wherein determining a variation in brightness based on differences in numerical values comprises comparing a plurality of pixels from at least three image frames acquired at different times, in which each compared image frame is spaced a selected number of frames from another compared image frame.

5. The method of claim 4, further comprising determining a pixel undergoing the greatest change among the compared image frames by calculating a sum of differences in numerical values for each of the plurality of pixels within the compared image frames.

6. A system for monitoring an object, comprising:

a device that acquires video image files comprising a sequence of video images, each video image comprising an individual image frame;

a memory for storing the video image files and a processor executing computer-readable program instructions configured to identify pixels in an image frame, which are defined by spatial coordinates within the frame;

wherein brightness within each pixel is characterized with numerical values such that at least one pixel in a first image frame is capable of being compared to a corresponding pixel in a second image frame having the same spatial coordinates;

the system being further configured;

to compare the first and second image frames and determine a variation in brightness based on differences in numerical values between the at least one pixel in the first image frame and the corresponding pixel or pixels in the second image frame, in which the variation indicates movement of the object;

to amplify the differences in numerical values between the two image frames by multiplying the difference by a predetermined factor to at least one amplified differenced frame;

to create at least one new image frame by superimposing the at least one amplified differenced frame onto the reference frame; and

and to provide to a user interface an output of the at least one new image frame.

7. The system of claim 6, wherein the device for acquiring video files is selected from the group consisting of:

video cameras, infrared imagers, webcams, and digital cameras integral in a mobile device.

8. The system of claim 6, wherein the system is further configured to display a plurality of image frames as a sequence of new image video frames.

9. The system of claim 6, wherein the system is further configured to determine a variation in brightness based on differences in numerical values by comparing a plurality of pixels from at least three image frames acquired at different times, in which each compared image frame is spaced a selected number of frames from another compared image frame.

10. The system of claim 9, wherein the system is further configured to determine a pixel undergoing the greatest change among the compared image frames, by calculating a sum of differences in numerical values for each of the plurality of pixels within the compared image frames.