Use of the FAROÂŽ Scanner Freestyle3D X in Crash Reconstruction By Divyam Patel, Karl Shuman, KEVA Engineering, LLC.
Abstract Crash reconstruction utilizes the analysis of physical evidence to apply physics in the evaluation of an incident. It is critical that investigators are able to quickly obtain accurate dimensional data of the scene and the vehicles involved in an incident. While the FARO Focus Laser Scanner is preferred to capture large objects and the overall site, the FARO Scanner Freestyle3D X produces excellent results for capturing critical details, such as minor marks, cracks, dents, discolorations, or debris. This white paper is the result of a demonstration performed by KEVA Engineering, LLC to describe the appropriate uses and applications for the FARO Scanner Freestyle3D X and explain the use of certain settings.
Equipment FARO Scanner Freestyle3D X is a high-precision handheld scanner able to produce detailed 3D scans in a matter of minutes. In testing, the Freestyle 3D X was paired with a tablet PC to give a real-time view of the 3D data while scanning. The ability to see the scan results immediately makes the Freestyle3D X adept at capturing and confirming critical details of a crash scene.
Figure 1.  Setup and scanning process with the FARO Scanner Freestyle 3D X.
The Freestyle3D X can be used as a standalone measurement device or in conjunction with other tools. The lightweight and portable nature of the device makes it ideal to document evidence details, such as gouge marks, vehicle deformations, and debris typically found at a crash site. As demonstrated in Figure 1, the Freestyle3D X is used to record fine details in relatively complex shape, such as a bicycle. For capturing an entire crash scene, the FARO Scanner Freestyle3D X complements the FARO Focus Laser Scanner by filling in scene gaps and capturing the details in areas of interest.
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Use of the FARO® Scanner Freestyle 3D X in Crash Reconstruction Methodology The Freestyle3D X is designed to optimally capture objects at a range of .5m to 3m, depending on the model chosen. The Freestyle3D X has a built-in flash system which enables the device to scan surfaces rapidly and with increased detail, including dark surfaces. Like with all scanners, to fully capture an object with the Freestyle3D X, you must have sufficient access all around the object. Additionally, the Freestyle3D X performs best when in an area sheltered from direct sunlight. The Freestyle3D X connects to a handheld tablet PC to control the Freestyle3D X settings and observe data results. If a handheld tablet PC is not available, a laptop can be substituted.
Figure 3. Use SCENE Capture to define the File name and destination, as well as flashdrive settings.
Continue moving the Freestyle3D X over the area you want to capture until it is completely highlighted. Once the data is captured, the next step is to import the scans into the SCENE software. Create a project file in SCENE, open the scan view window and then drop the LSPROJ Freestyle3D X file into the window. This will import all the scans that were performed. After importing is complete, right click on the “Scans” folder on the tree on the left and
Figure 2. Depth Range and marker detection settings in SCENE Capture.
SCENE Capture, installed on the handheld tablet PC, is used to control the Freestyle3D X’s settings. The “Options” tab in SCENE Capture has some important settings that should be reviewed before scanning. In testing, the “Depth Range” was set at five meters since all the scans performed were no further than five meters away. When using targets while performing scans, select “Marker Detection”, as shown in Figure 2. The targets in our study were printed on paper and fixed on or around the subject. For best results, place the targets on or around the subject and always capture the targets with overlapping scans. In the “Capture” tab, the file name and destination for the scanned data is entered, as noted in Figure 3. While performing a scan, the SCENE Capture will highlight areas in real time when adequate data has been captured, as shown in Figure 4. This real-time display helps the user adjust the scanner to ensure all the important details are documented.
Figure 4. SCENE Capture software highlights the areas of a bicycle scanned with the Freestyle 3D X.
select “Process Scans” under the Operations Tab to create a point cloud for each scan. Once processed, you can begin aligning the scans by clicking on the “Freestyle” tab at the top and then clicking on “Start / Stop Scan Placement”. Scans will then be aligned with the help of the markers placed on the subject. Finally, you can save the data as a PTS file so the final point cloud can be opened in other software for analysis or diagramming.
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Use of the FARO® Scanner Freestyle 3D X in Crash Reconstruction Practical Applications: Scanning Bicycles And Motorcycles Scanning a bicycle can be challenging since they are relatively small and have an open structure with intricate detail. Using a tripod-mounted laser scanner, multiple scan positions are required to capture the details of a bicycle. In testing a damaged bicycle, the FARO Scanner Freestyle3D X was shown to be an excellent tool to capture details in 3D. Figure 5 shows a scan of a bicycle on a stand captured using a FARO Scanner Freestyle 3D X. The scans were aligned using SCENE software with minimal post-processing required. Targets can be seen on a few of the bicycle’s surfaces. The Freestyle 3D X was able to capture the fine details of the bicycle, including the handlebar and damaged spokes. The FARO Scanner Freestyle3D X was also used to scan a motorcycle on a stand, with a total of four scans captured. The scans were later imported into SCENE and registered into one point cloud. The resulting point cloud, shown in Figure 6, shows the intricate details of the motorcycle captured.
Figure 5. SCENE Capture software highlights the areas of a bicycle scanned with the Freestyle3D X.
Summary Through testing, the FARO Scanner Freestyle3D X was shown to capture small objects and document details effectively. The portability of the FARO Scanner Freestyle3D X makes it an ideal tool to document evidence, scan complex objects and digitally capture hard to reach areas. At a large crash scene, the Freestyle3D X is an excellent tool to obtain point clouds of small marks and vehicle interiors which could be combined with an overview of the site captured with a long range FARO Focus Laser Scanner. Overall the FARO Scanner Freestyle3D X is a useful addition to the toolkit used by Accident Reconstructionists.
Authors
Divyam Patel and Karl Shuman, KEVA Engineering 840 Calle Plano Camarillo, CA 93012 www.kevaeng.com 805-388-6016
Figure 6. Point cloud of a motorcycle scanned with the FARO Freestyle3D X.
KEVA Engineering offers state of the art vehicular accident reconstruction, testing, safety research and expert testimony. Their consulting activities involve collision analysis, vehicle dynamics and handling, rollover analysis, computer simulation, computer modeling, testing design, heavy truck dynamics, crashworthiness, laser scanning and EDR analysis.
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