Engineering R&D Dr.-Ing. Alexander Gerhard Crash markers: DOT + MXT + QUAD + MXT + DOT
 
FAQ
 

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.
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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 hot keys assist with user handling of FalCon eXtra?
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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!


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...
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Please click here for detailed instructions (pdf) 

Which evaluation method shall I use?
Standard or Full Evaluation and the sigma icon...
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Please click here for an explanation and detailed instructions (pdf) 

Which certificates and procedures help for quality assurance?
Utilities, standards and recommendations...
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Please click here for a detailed background (pdf) 
 
    Fimstripe: Top View Car Crash

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Engineering R&D Dr.-Ing. Alexander Gerhard · phone +49-89-28 44 44 · mail 
info@dr-gerhard.de