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On this page we would
like to answer frequently asked questions.
You are welcome to send your
questions and suggestions
via e-mail.
QUESTIONS & ANSWERS
General
Which markers shall I use in my test?
FalCon supports the
crash proven 5-spot markers (MXT), 1-spot markers (DOT) as well as the known
QUAD targets and common correlation markers. In particular for 3D applications
coded markers (AICON) are available.
->
Please click here for further details
(pdf)
Where can I purchase self-adhesive markers?
The print shop Franz
Maier (see
Links)
offers self-adhesive DOT and MXT markers in different sizes. Ask for special
glue which sticks well on textiles and which is temperature-resistant. The glue
must not affect the dummy skin.
Which accuracy have image measurements?
Depending
on marker type and size the achievable accuracy is mostly better than 0.2
pixel.
-> Please click here for
further details (pdf)
Which video compressor shall I use?
The so far widely used
codec (= encoder + decoder) Indeo Video 5.1x shows only restricted
utilizability since Windows
7: a replay of videos in the
Media Player via network is no more supported!
Windows 8.1/10 offers instead the feature of playing files of MPEG4/ASP/AVC
format without further installations of decoders.
Therefore we recommend for FalCon eXtra the encoder x264.
->
Please click here for further details
(pdf)
Hint:
For videos with charts or drawings, like diagrams with moving cursor, the
Microsoft Video 1 codec is most suitable, because even thin lines do not show
compression artefacts.
Which hotkeys and shortcuts assist with user handling of
FalCon eXtra?
->
Please click here for an overview
(pdf)
MovXact 2D Analysis
Which princples are behind a 2D motion analysis?
Set-up requirements,
parallax errors and socalled principle point...
-> Please click here for a
detailed overview (pdf)
How accurate can I measure by means of 2D motion
analysis?
-> Please click here for a
discussion of factorable influences
(pdf)
Mov3D 3D Analysis
Which princples are behind a 3D motion analysis?
Stereoscopic analysis,
camera set-up and terms...
->
Please click here for a detailed
overview (pdf)
Need the cameras be temporally synchronized?
Yes, definitely! In order to avoid spatial measuring uncertainty or errors
during 3D triangulation, the point coordinates from the stereo views need to be
defined at the same time sample. Therefore make sure that the used cameras have
an identical trigger behavior and compensate any T0 delays. Also choose common
exposure times of the cameras. Please note that for subsequent 3D analysis only
identical recording rates make sense.
A time delay between T0 and the real start of the recording might lead to a
strong influence in 2D analysis too.
Example:
Assuming an uncertainty of max. 1 ms (@ 1000 fps) and an impact velocity of 50
km/h, the measurement of the absolute displacement will show an error of about
14 mm!
Which layout of APT text file is used for control points?
Control points, marker
names, 6D objects...
-> Please click here for a
detailed specification
(pdf)
->
Please click here for a
sample file (apt)
How accurate can I measure by means of 3D motion
analysis?
->
Please click here for a
discussion of factorable influences
(pdf)
CamFolder Camera Calibration
How do I take pictures of the test panel?
Recording
positions according to the 7plus scheme, illumination and image processing...
->
Please click here for detailed
instructions (pdf)
Which evaluation method shall I use?
Standard
or Full Evaluation and the sigma icon...
-> Please click here for
an explanation and detailed instructions
(pdf)
Which certificates and procedures help for quality assurance?
Utilities, standards and
recommendations...
->
Please click here for a detailed
background (pdf)
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