Optical Coordinate Measuring Techniques for the Determination and Visualization of 3D Displacements in Crash Investigations

Abstract

The measurement of 3D coordinates using optical techniques is well known for more than 50 years. Today, modern photogrammetric systems are based on handheld digital cameras and are used to identify the location of any circular marker or feature on the object's surface. The ease of use and the accurate and automated derivation of 3D coordinates from 2D digital images helped to establish a powerful tool for position control, assembly checks and reverse engineering. A new application is the analysis of real vehicle crashes. The location of hundreds of markers on the damaged vehicle can easily be determined in vehicle body position. These coordinates are being compared to the undeformed geometry and provide herby 3D information on any displacement. Using reverse engineering techniques, surfaces are created from the 3D points and thus a 3D model of the crashed vehicle is available for an easy visualization of the deformation.

Virtobot—a multi‐functional robotic system for 3D surface scanning and automatic post mortem biopsy

“…3D surface scanning and photogrammetry The TRITOP component of this system is based on multi-image photogrammetry (15,16). Digital photos are taken with a Nikon D2X digital camera (Nikon Corp., Japan) and submitted wirelessly to the TRITOP system.…”

A Survey of Multi-View Photogrammetry Software for Documenting Vehicle Crush

“…There are a number of close-range photogrammetry software titles available including some that require calibrated cameras, coded targets [10,11] or manual correlated pixel selections in multiple photographs [3,8]. These titles do not all return data in the form of a point cloud.…”

“…Photogrammetry has been previously validated as an effective technology for documenting both damaged vehicles and scenes [1,2,3,4,5,6,7,8,9,10,11,12]. Modern photogrammetry uses the same photogrammetric principles, but requires less user input and delivers more data points in its solution.…”

Improving post-mortem surface documentation with a CT mounted marker board

“…A standard method for photogrammetric reconstructions involves ring coding markers, which take the form of standardized circular pads with a black background, a white central point and a white surrounding circular structure [10]. The last feature varies from marker to marker, a fact that allows the software to recognize each individual marker and to code it with a specifically assigned number.…”