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

· $Description: H:\Privat\Dissertation\Messtechnik\High Speed Kamera\Software PTV\3D PTV\cam_1.tif.ori.tif$ The 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

· $Description: H:\Privat\Dissertation\Messtechnik\High Speed Kamera\Software PTV\3D PTV\main parameters.tif$ No 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

· $Description: H:\Privat\Dissertation\Messtechnik\High Speed Kamera\Software PTV\3D PTV\tracking parameters.tif$ 2D 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