| Popis: |
Dandanes živimo v razkošju vse bolj naprednih naprav, ki so z nami na vsakem koraku in nam pomagajo pri raznih opravilih. Ne zavedamo pa se, da se z uporabo teh naprav veča tudi izpostavljenost vibracijam, ki so lahko na dolgi rok nevarne za zdravje. Z analizo teh nihanj, bi se lahko pred njimi ustrezno zaščitili. Vnos vibracij v prst se tipično meri s kontaktnimi zaznavali (npr. pospeškomer, silomer) ta prispevek pa raziskuje možnost merjenja nihanja prsta s pomočjo hitre kamere. Prednosti, ki ju ponuja hitra kamera sta: veliko število sočasno merjenih točk in ker ni masne obtežbe s tem ni vpliva na meritev. Za analizo posnetka je bila uporabljena gradientna metoda, ki sloni na optičnem toku. Analiza poteka pri različnih vzbujanjih, ter različnih položajih prsta (kazalca) na viru vibracij. Pri vzbujanju na distalni falangi smo ugotovili, da so najbolj vzbujanje frekvence pri 13, 31 in 39 Hz, na srednji falangi pa pri 13,5 19 in 26,5 Hz. S predstavljeno metodo smo pokazali, da lahko z optičnim tokom precej natančno analiziramo tudi nehomogena telesa, kot je človeški prst. Nowadays we live in luxury of more and more advanced devices, which follow us at every turn and help us accomplish different tasks. However, we're not aware, that the use of these devices increases the exposure to vibrations, that may be dangerous to our health in the future. By analyzing these vibrations, we could be adequately protected against them. Vibrations in the finger are typically measured by contact sensors (e.g. accelerometer, force meter) this paper explores the possibility of measuring the finger oscillations, by using the high-speed camera. The advantages offered by the high-speed camera are: Large number of simultaneously measuring points and since there is no extra mass on the finger, it has no impact on the measurement. For image analysis gradient method was used, which is based on the optical flow. The analysis takes place at various excitations and finger positions (pointer) at the source of the vibrations. In the excitation on the distal falang, we found that the most excited frequencies are at 13, 31 in 39Hz and on the middle falang at 13.5, 19 and 26.5 Hz. By using the presented method, we have shown that even non-homogeneous bodies, such as human finger, can be analyzed quite accurately with the optical flow. |
