Considering imperfections using 3D imaging system in angle obtaining, angle signal distance computing and multivariate distance graphing

Fields such as medicine, biomechanics or ergonomics need to measure the positions and the rotational movements of body segments. The aim of this article is to underscore the problem of imperfection on angle measurement using a three-dimensional television system. First, the error on a single angle value is assessed through the classical Taylor's formula and through a simulating approach. Then the error is considered for an entire signal through either an experimental design or a simulating approach. To take into account such an error when comparing two angle multidimensional signals, a specific coding technique is suggested. Finally, two graphical patterns are proposed to show globally the distance between the signals with regard to the error.