| タイトル | Anthropometry and Biomechanics Facility Spring 2016 Internship |
| 本文（外部サイト） | http://hdl.handle.net/2060/20160006075 |
| 著者（英） | Boppana, Abhishektha |
| 発行日 | 2016-05-16 |
| 言語 | eng |
| 内容記述 | The Anthropometry and Biomechanics Facility (ABF) at Johnson Space Center supports the Space Human Factors Engineering portfolio of the Human Research Program. ABF provides capability to verify the accommodation and comfort of crewmembers through anthropometry and biomechanics analyses. Anthropometric measurements are derived from three-dimensional (3D) whole body scan images. The scans are currently taken by a Human Solutions Vitus 3D Laser Scanning System. ABF has purchased a 3dMD photogrammetry scanner system to speed up the process of collecting 3D scans. The photogrammetry scanner system features a faster data collection time, as well as fewer holes in the scans. This internship was mainly focused on developing calibration, measurement, data acquisition, and analysis processes for the new system. In addition, I also participated in a project to validate the use of a pressure mat sensor on the shoulder during in-suit testing. My duties for the scanner validation project started with identifying and documenting a calibration process. The calibration process proved vital to using the system as the quality of the scans was directly related to the success of the calibration. In addition, the calibration process suggested by the system vendor required the user to hold a large calibration board at precise locations. To aid in this, I built a calibration stand which held a calibration board at constant positions throughout numerous calibration process. The calibration process was tested extensively until proven acceptable. The standardized process reduced calibration time from over 10 minutes to just below three minutes. As a result, the calibration process could be completed painlessly and precisely, and scan quality was constant between sessions. After standardizing the calibration process, I proceeded to modify the locations of the cameras in order to capture the full volume of a person. The scanning system needed to capture a full T-pose of a person in one scan. Adjusting the cameras also allowed me to ensure that there was maximum scanning volume overlap between multiple cameras, resulting in a higher fidelity. This process was completed through trial and error, by systematically moving cameras until a full pose could be captured. In addition, I refocused each cameras in the system to improve accuracy. Next, I fixed various hardware issues related to the scanning system. These issues included missing images, loss of power, and printed circuit board failures. To solve these issues, I contacted the vendor and brainstormed possible failure modes with them. Many of the issues were solved by modifying the camera hardware to reduce stress on components. Currently, I am working on identifying the best measurement technique for the scanner. This involves identifying an anthropometric marker which can be used for landmark identification. Various colors and sizes of stickers are being evaluated for their use as an anthropometric landmark. I programmed a script which can isolate these markers from the scan, and identify them as landmarks. The script is being used to evaluate how well the markers can be seen against various skin tones and colors. This script may also be useful in the future for automatic landmark identification as well as automatic anthropometric measurements. In the future, software needs to be evaluated for measurement extraction. This will be done by measuring known objects as well as human subjects, and measuring using various proposed methods. Parameters tested will include extraction times, number of correction rounds, and the accuracy/precision of measurements. The most reliable method will be recommended for use with the 3dMD scanning system. This part of the project will be completed through the summer internship session. The pressure mat validation project involved designing and carrying out a test to validate the outputted data. The test consisted of collecting data from applying a constant known load on the pressure mat in a variety of surfaces. In addition, different analysis methods were also tested. Historically, ABF has analyzed pressure mat data by looking at the maximum pressure. However, it was found that this pressure might be an outlier due to uneven load application or force transduction. Therefore, I wrote a new script which would calculate the total load on the pressure mat by looking at an area around the total pressure; this script proved to provide much more useable data and is now being used to retroactively analyze previous data collected by the pressure mat. This internship has impacted my career and internship goals in a very positive way. I have learned how to work with both NASA employees and outside vendors. In addition, I have learned many techniques related to 3D-scanning and anthropometric measurements, which will serve to further supplement my education. Finally, I have had the great opportunity to ask my co-workers for advice regarding graduate school. They have been invaluable in helping me find graduate programs which fit my interests. |
| NASA分類 | Aerospace Medicine |
| レポートNO | JSC-CN-36227 |
| 権利 | Copyright, Distribution under U.S. Government purpose rights |
| URI | https://repository.exst.jaxa.jp/dspace/handle/a-is/562999 |
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