The experimental rig of the triple physical pendulum with the first body periodically forced is built. A mathematical model of the real pendulum is created. Friction in joints is modeled as a composition of dry friction and damping. The parameters of the model are estimated matching the output signals from model and experiment. For the minimum searching of the matching function the simplex method is used. Very good agreement between model and real system is obtained. Few chaotic zones are detected numerically and confirmed experimentally.