Dear Customer,

you want best service, best software, and best know-how in the area of

• High speed imaging and digital video technique
• Measurement data acquisition, transfer and management

for automotive impact and airbag testing.

That's why you have to meet FalCon - the innovative Bavarian company.

FalCon provides you with software products you are looking for. And with the legendary FalCon consulting, training and service.

We are specialized in turn key systems.

Our High-Speed Video Products

FalCon offers you software tools for automotive crash tests:

• control your high-speed cameras and create AVI files,
• view synchronized videos and measurement graphs,
• present multi-media test data to your customers,
• use robust tracking for exact motion analysis,
• measure outlines of airbags,
• calibrate your lenses and go to 3D
• and ask us for a sophisticated concept of a test archive!

Our target: you

Thanks to our 20-years experience on the international market, and thanks to our close and successful cooperation with most of the big shots on the market (producers and institutions), our products are always state-of-the-art. We permanently scan for the needs and proposals of our customers and integrate their suggestions into our products, quickly. The result is just what you need: absolute top quality in every aspect.

Of course, we promote the international standardization of data interfaces by cooperating actively in working groups and supporting available standards.

Organized to meet your standards

Software development and hardware design is what you get from FalCon - right from the "Bavarian Silicon Valley". That is why we guarantee for absolute high-tech and absolute quality.

If necessary, we closely co-operate with our top expert partners, who bring profound knowledge and top practical experience into our products - and so to you.

Our sales department and our international representatives support all our customers world-wide: partners, mainly in the research and development departments, or wherever we can help you.

Time to meet the friendly FalCon, isn't it?
Please visit us for more information and free software downloads: www.FalCon.de

FalCon
Falkner Consulting for Measuring Technology GmbH
Lohenstr. 16
D-82166 Graefelfing-Lochham
Germany
Tel. +49-89-851088
Fax +49-89-851027
Web: www.FalCon.de
eMail: Mov3D@FalCon.de

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3D Impact Test Analysis using High-Speed Video Software
Dr Alexander Gerhard, FalCon Partner

Leave the plane and measure real 3D motion using stereo vision!

High-speed cameras are indispensable tools for automotive impact testing. Replaying image sequences in slow motion allows the test engineer to gain an insight into the dynamic processes taking place during crashes. Image analysis also provides calibrated measurements of displacements.

Over the last ten years, high-speed video imagers have increasingly replaced 16-mm film cameras. This means that the processing of film is no longer restricted to special equipment in test labs; digital videos can now be accessed, displayed and processed by standard PC workstations within the company network.

The same quick development can be seen in the field of analysis: while manual digitizing of points in projected film images was quite time-consuming, state-of-the-art software solutions now facilitate the automatic, reliable and reproducible tracking of markers.

Nevertheless, there is a physical limitation with one-camera setups in that only 2D motion can be measured and the camera must be aligned exactly perpendicular to the motion plane. This means that a ‘monocular view’ is not appropriate for oblique testing or the measurement of real spatial dynamics.

We would therefore like to introduce you to FalCon eXtra Mov3D analysis software which is able to perform 3D analysis using stereo vision:

	Oblique impact testing at TNO
	Extended ISO/SAE Panel

Camera calibration
3D photogrammetry starts by focusing on the calibration of camera and lens, because the accuracy of triangulation depends to a great amount on the quality of the imaging. While the ISO 8721 / SAE-J211/2 standard gives only a rough threshold for ‘good lenses’ with its Distortion Index, it is necessary to evaluate the accurate distortion and imaging parameters of the camera (= ‘interior orientation’). The FalCon software supports the ‘5-rings panel’ according to ISO/SAE; additional so-called ‘coded’ points allow the automatic identification of markers. We recommend taking several images with different tilt and rotation angles as input data of a calibration procedure. The software then measures the image coordinates of all points automatically and calculates the modelled camera parameters⁽¹⁾. This will take only few minutes per camera!

The FalCon eXtra CamFolder module gives you access to all calibrated camera/lens combinations in a Windows tree view. During analysis, a calibration dataset can be simply applied in the session via drag-and-drop. The geometric measurements will be rectified according to the inverse distortion parameters.

Camera positions
Instead of mounting the cameras with fixed geometry, we use a self-positioning method. For this several (≥ 4) control points with known 3D coordinates are fixed in the field of view of each camera. (Their locations should be pre-measured by a photogrammetric device or a mechanical test probe.) The positions of the cameras (= ‘exterior orientation’) are calculated via resection in space using the measured image coordinates of the control points. In case of unsteady cameras, e.g. on a sled, the positions may be defined as ‘dynamic’ in order to be updated in each image of the sequence.
 

Camera Position by x,y,z + 3 angles

3D measurements
Measuring dynamic 3D trajectories of unknown points requires that each target in the object space is recorded simultaneously by at least two cameras. The operator must set up and track these markers in each view. The software handles this step in a similar way to 2D image analysis. The 3D triangulation (= ‘intersection in space’) processes these measured image coordinates along with the calibration parameters and the camera positions, yielding the 3D coordinates of the markers. This works properly if all cameras run synchronously, something which is problematic in the case of film cameras, but not generally when digital video cameras are used.

The scaling and definition of the common coordinate system is implicitly included in the control point information used for the camera positions; no additional scales are necessary.

3D Pendulum Test		Test Set-up at TNO

Application examples
FalCon Mov3D has proved to be accurate and fit for practical use in an experiment carried out by German automotive companies in which the measured length of a moving pendulum (800 mm) could be measured with a standard deviation < 0.4 mm.

Dummy targets

Trajectories of Head Targets

Recently, the 3D kinematics of a Hybrid III dummy were evaluated during oblique impact tests, as part of an international project. TNO Automotive R&D decided to use high-speed video cameras and the FalCon Mov3D analysis software for this task.

The measuring volume had to cover a dynamic range of at least 2000 mm. We therefore installed the cameras at an angle of 25 degrees to the direction of sled motion. Custom targets needed to be developed allowing large out-of-plane rotations and automatic tracking with high accuracy. Some pilot tests were carried out to evaluate the use of retro-reflective spherical targets in combination with small halogen lights. The spots were assembled with the camera housing enabling the lighting to be well directed in camera’s line of sight.

Images of a calibrated cubic object (instead of singular control points) were taken prior to the test. The program measured the centers of its bright targets with sub-pixel accuracy and combined them with the corresponding 3D coordinates (measured manually by FARO) in order to calculate the camera positions.

We used quite a solid conventional SAE J211/2 panel for camera calibration. The results proved the high quality of the lenses used and also doubled the measurement accuracy: SAE Distortion Index = 0.12 % (calibrated).

FalCon Mov3D was able to automatically track all unknown points in the stereoscopic views. Despite the low video resolution and the motion in the line of view, the 3D measurements are highly reproducible and very accurate: the distance of two targets on the dummy’s head, for example, does not vary more than 0.5 mm during 250 ms.

(1) See documentation on calibration of cameras by FalCon Partner AICON 3D Systems GmbH: http://www.falcon.de/falcon/eng/documentation.htm

For more information contact:
FalCon
Falkner Consulting for Measuring Technology GmbH
Lohenstr. 16
D-82166 Graefelfing-Lochham
Germany
Tel. +49-89-851088
Fax +49-89-851027
Web: www.FalCon.de
eMail: Mov3D@FalCon.de

 

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