This paper presents a new biped mechanism with low-cost easy-operation features. The mechanism is designed with functions for straight walking, changing direction, overcoming obstacle, and climbing stairs with only 7 DOFs (degrees of freedom). Dynamics of the biped mechanism are analyzed by means of simulations in the MSC.ADAMS environment. Simulation results in terms of motion torque, joint force, contact force, parts displacement, velocity, and acceleration are reported and analyzed to show the feasibility and efficiency of the proposed solution. In addition, with the simulation results, dynamical motion of the biped mechanism is investigated and its operation performances are characterized as well.

The questions when and why one needs to use mathematical models, and especially the models of dynamics, represent still an unresolved issue. A general answer would be that dynamic modelling is needed as a tool when designing structure of the system and its control unit. In this case we talk about simulation. The other application is in on-line control of the system – the so-called dynamic control. While in simulation one generally uses the best available model, the control can be based on a reduced dynamics, depending on a particular task. The aim of this paper was to highlight the problems important for the dynamics of humanoids and their dynamic environment.