FPGA Implementation of Digital PIV

Objective

People

Project Description

Publications

　

Objective

  Particle image velocimetry(PIV) is a measuring technique tocapture the flow velocity. Small particles are added into the fluid and their movements are measured by comparing two images taken within a short time interval of the flow field using cross-correlation. 
  Cross-correlation is a very computation intensive algorithm and software implementation cannot meet the real-time system requirement. Our FPGA implementation of digital PIV system can process 15 pairs of images per second, which is fast enough for our application.

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People
Miriam Leeser Professor Northeastern University
Gilead Tadmor Professor Northeastern University
Haiqian Yu PhD Student Northeastern University
Stefan Siegel Assistant Research Associate US Air Force Academy

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Project Description

Digital PIV System

  • Fluid is illuminated twice by two consecutive pulses of a laser.

  • CCD camera captures two images.

  • Local particle movement is estimated by using cross-correlation for each interrogation area.

  • Cross-correlation is very computational intensive and needs hardware speedup for real-time system

Solution

  • System Diagram


　

  • Hardware

　

  • Pipeline structure of cross-correlation

Performance

  • Image Size: 1008 by 1016

  • Interrogation area: 40 by 40 and 32 by 32

  • Overlap: 50%

  • Subpixel interpolation: Parabolic peak fit

           (a) Hardware vs. Software; (b) Complete Interrogation vs. Selected Area Interrogation

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Publications

§             “Real-time Particle Image Velocimetry for Feedback Loops Using FPGA Implementation”

Haiqian Yu, Miriam Leeser, Gilead Tadmor and Stefan Siegel, 43rd AIAA Aerospace Sciences Meeting and Exhibit, 2005.

§             “Smart Camera Based on Reconfigurable Hardware Enables Diverse Real-Time Applications”

Miriam Leeser, Shawn Miller, Haiqian Yu, Pages 147-155, FCCM'04, 2004

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This material is based upon work supported by the National Science Foundation under Grant No. 0410246.

Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

Last updated on 4/14/2006.