A mathematical model of a system consisting of a dc motor, mechanism converting the rotational
motion to the linear one and a single physical pendulum with the joint horizontally driven is
developed. Constant angular velocity of the crank is assumed. The parameters of the model are
estimated using the experimental data consisting of five solutions corresponding to the five
different values of constant input voltage. Different versions of the mathematical model, with
different details concerning friction and damping modelling, are tested. A good agreement between
real and simulated behaviour of the system is obtained. Moreover the model is validated by testing
its ability to predict critical values of the bifurcation parameter.