Mutibody modelization of a biped robot

The present work develops a multibody dynamical model of a planar biped robot called Rabbit, the same that considers external forces which act at the moment of the ground-feet contact. Moreover, the ground-feet contact forces where modeled. The multibody dynamical model of Rabbit was implemented in Robotran, software that generated symbolic files of the dynamical equations of the model in Matlab syntax. These dynamical equations and the ground-feet contact external forces were implemented in a Simulink model for simulation purposes. The model was validated though a Simulink implementation of the torque generator and control blocks of the real robot. The results showed that the model required adequate torques, which must be generated on the basis of designed trajectories, assuring the dynamical stability of the gait. In addition to this, the adequate frictional forces acting on the feet of the model proved to prevent the robot from slipping on the walking surface and falling. In conclusion, for achieving a stable gait, an adequate dynamic model that assures stability is not only necessary, but a correct design that could be fitted for the torque generator of the real robot is necessary as well.