STEP-BY-STEP INSTRUCTION FOR EXAMPLE E

This is an example that 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 10000 fps to capture the head bang motion of a termite. This image group includes 3000 frames, and a ruler image is used to determine the object to image ratio.

 

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 \ e_InsectBodyPartMotion”;

- 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;

- Select menu “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 9 in edit box “Reading on ruler [mm]”;

- Input 179 in edit box “Corresponding pixels”;

- Input 100 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” in the start window;

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

- Select menu “Tools \ Image pattern tracking”;

- Move the mouse arrow to (30,94) and click left mouse button - dialogue box “Image pattern for calibration marker search” appears;

- Set parameters as
IPT settings:
Raw image, freedom limit=10
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 \ Postprocessing \ Gradient”;

- Set 1 to both “forward step” and “backward step” in dialogue box “Discrete gradient”;

- Press “OK” button in the dialogue box;

- Click menu “File \ Save data” to save the velocity time history.

- Click menu “Edit \ Single PIT/IPT \ Postprocessing \ Gradient” again, and set 1 to both “forward step” and “backward step”, to compute head moving acceleration time history;

- Click menu “File \ Save data” to save the acceleration time history.

Step 6: Make plots with TECPLOT software

- Close EDPIV;

- Use TECPLOT to make plots.

 

Displacement time history:

 

Velocity time history:

 

Acceleration time history: