STEP-BY-STEP INSTRUCTION FOR EXAMPLE C

This example shows how to determine the displacement time history of a moving insect body part with the image pattern tracking (IPT) method. A group of images were acquired with a high speed imaging system at a frame rate of 4000 fps to capture the vibration of a fire ant antenna in a near sound field of 700 Hz. The object to image ratio is 2.58 μm/pixel.

 

Step 1: Create image file list

- Execute file “Edpiv.exe” - The start window is shown on the screen;

- Select menu “Edit \ File list” - Dialogue box “Creating file list” appears;

- Press “Input files” button - Dialogue box “Data file list” appears;

- Browse hard drives to find folder “…\ PIVsamples \ c_SoundInducedMotion ”;

- Arbitrarily select one of the Windows Bitmap (BMP) files in the folder;

- Press “Open” button - Dialogue box “Data file list” is closed;

- Press “Output file” button - Dialogue box “Data file list” appears again;

- Browse the hard drives to find a destination folder;

- Type a name for the file list in the edit box indicated by “File name”;

- Click “Save” button - Dialogue box “Data file list” is closed;

- Set “Recording type” to 3;

- Press button “Create” to generate the image file list;

- Close the dialogue box to return to the start window.

Step 2: Open the image group

- Click menu “File \ Image group” in the start window - Dialogue box “Recording group” appears;

- Browse the file system to find the image file list created in step 1;

- Click “Open” - The first frame of the image group is shown in the window.

Step 3: Input imaging scale and time interval

- Click menu “Edit / Scale & time” in the start window to open dialogue box “Imaging scale / time interval”;

- Input 387596 in edit box “Img/obj ratio [pix/m]”;

- Input 250 in edit box “Time interval [mu-s]”;

- Press “OK” button to return to start window.

Step 4: Tracking an image pattern and save the data

- Press button “Evaluation” to open “Evaluation” window;

- Increase the window size to clearly see the image pattern;

- Select menu “Tools \ Image pattern tracking” ;

- Select image pattern at (52,104) and click left mouse button - dialogue box “Image pattern for calibration marker search” appears;

- Set parameters as
IPT settings:
Raw image, freedom limit= 100
W width [pix]: 24
S radius [pix]: 6
and then press button “C”;

- Press “OK” to start the image pattern tracking - dialogue box “Group evaluation” appears;

- Press “OK” in dialogue box “Group evaluation”;

- Wait until the evaluation is completed;

- Click menu “File \ Save data” to save the raw results in a file.

Step 5: Data postprocessing

- Click menu “Edit \ Single PIT/IPT \ Data on/off” to display the displacement time histories in the window;

- Click menu “Edit \ Single PIT/IPT \ High/low-pass filter” to setup parameters as
High-pass filter: r=20
Low-pass filter: r=0

- Press button “Ok” to complete the filtering;

- Click menu “File \ Save data” to save the processed time histories in a file.

- Click menu “Edit \ Single PIT/IPT \ Postprocessing \ Fourier analysis (FFT)” to complete a fast Fourier transformation;

- Click menu “File \ Save data” to save the FFT results.

Step 6: Make plots with TECPLOT software

- Close EDPIV;

- Use TECPLOT to make plots.

 

A. Raw displacement:

 

B. FFT results: