Mensa, G., Parera, N., and Fornells, A., "Camera Alignment System for Passive Safety Crash Tests," SAE Technical Paper 2017-01-1675, 2017, doi:10.4271/2017-01-1675.
Nowadays, the use of high-speed digital cameras to acquire relevant information is a standard for all laboratories and facilities working in passive safety crash testing. The recorded information from the cameras is used to develop and improve the design of vehicles in order to make them safer. Measurements such as velocities, accelerations and distances are computed from high-speed images captured during the tests and represent remarkable data for the post-crash analysis. Therefore, having the exact same position of the cameras is a key factor to be able to compare all the values that are extracted from the images of the tests carried out within a long-term passive safety project. However, since working with several customers involves a large amount of different cars and tests, crash facilities have to readapt for every test mode making it difficult for them to reproduce the correct and precise position of the high-speed cameras throughout the same project. Thus, the system developed through this work uses an image processing algorithm to locate the cameras by taking images from at least four sides of the laboratory with multiple cameras, avoiding occlusion problems, by recognizing the binary square markers attached to the high-speed camera housing. Furthermore, relevant information such as the serial numbers, focal lengths and/or calibration files; can be stored in each camera fiducial marker in order to increase the accuracy of the test repeatability.