3D PTV

3D-PTV

3D Particle Tracking Velocimetry software on Github ( http://3dptv.github.com )

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Manual 3D PTV Software

documented by Christian Auel

Device: 1 High-Speed Cam pco.edge (2D PTV)

·       Pictures have to be 8 bit TIFF files

1        Change Calibration parameters

· Camera 2 to 4 not installed

TIFF Header: on

All paths are relative paths e.g.

Working directory has to be set to C:\PTV\working_directory (or similar named) in C++ 2010 express

Orientation data: file has to be prepared in ASCII format (see below)

File of coordinates: Defines the target dots on the calibration plate

File of coordinates: ASCII File

Target_on_a_side.txt

1. Column: Number

2. Column: X [mm]

3. Column: Y [mm]

4. Column: Z [mm]

 

Every target point has to be set

1.1       Target recognition on plate

·       Defines the grey values and size of the dots on the target plate.

·       8 bit: 256 colors

1.2       Point number for manual pre-orientation

·       Four points on the plate have to be defined before. Best on the four edges of the plate.

1.3       Orientation parameters

·       Check principle distance (focal length), xp, yp

·       Lens distortion and rows above are less important

·       Description: H:\Privat\Dissertation\Messtechnik\High Speed Kamera\Software PTV\3D PTV\cam_1.tif.ori.tifThe values have to be set in an ASCII file: cam1.tif.ori

Orientation data: cam_1.tif.ori

·       Zero point definition

·       Defines the coordination system (X: in                     flow direction, Y: vertical, Z: spanwise.          Right hand rule)

 

·       Columns:

1.     : X,Y,Z in [mm]

2.     Angles, if Cam is inclined [gon]. [0,0,0] cam is horizontal; Cam directs in -Z

3.     4. 5. Nothing important

6.     Xp, yp [micro m]. Can be set to [0,0] in most cases.

7.     Principal distance (focal length)

8.     Defines the exact position of the glass plate. [X,Y,Z]

2        Change Main Parameters

·       Description: H:\Privat\Dissertation\Messtechnik\High Speed Kamera\Software PTV\3D PTV\main parameters.tifNo of Cams: 1

·       Picture folder: img

·       Copy pics into img folder

·       Rename files: <name>.10000; incrementing

·       Refractive indices: 1.0, 1.33, 1.46

·       Parameters for particle recognition [mm]: see           calibration plate dots; 8bit

·       Tolerable discontinuity: overlapping size of two        particles in [mm]

Illuminated layer data

·       Window size to look at the particles

Correspondences

·       Not important

 

 

 

 

 

3        Change Tracking Parameters

·       Description: H:\Privat\Dissertation\Messtechnik\High Speed Kamera\Software PTV\3D PTV\tracking parameters.tif2D Tracking

·       Unit [mm/frame]

·       Angle: default: 180

·       Dacc: acceleration [mm/frame2]

·       Lower part (new tracking) not important

 

 

 

 

 

 

 

4        Results

·       Folder: res

Description: H:\Privat\Dissertation\Messtechnik\High Speed Kamera\Software PTV\3D PTV\rt_is.10001.tif

File: rt_is.10001 (Columns: No,         X, Y, Z, Cam1, Cam2, Cam3,             Cam4)

·       No. top left: number of detected        dots

 

·       Folder: img

File: cam1.10001_targets

Description: H:\Privat\Dissertation\Messtechnik\High Speed Kamera\Software PTV\3D PTV\targets.tif

·       Folder: res

File: ptv_is.10001

Description: H:\Privat\Dissertation\Messtechnik\High Speed Kamera\Software PTV\3D PTV\ptv_is.tif

Columns: frame before, frame after, X, Y, Z,

-1: dot not found

Plot column A and B in excel: Diagonal