Motion control and efficiency analysis of a special design five-link biped robot with torso

In this paper, we study motion control of a 5-link planar biped robot with torso without ankle and a special design such that the center of mass (COM) of the lower body is located at the hip. Using optimization of mechanical work and considering periodic and stability conditions with no slipping and no bouncing at heel, gait planning is determined as functions of a time scale parameter. Upon designing a controller, these trajectories are tracked. Simulation results are presented to show stability of the motion in this biped. Additionally, the effect of torso on energy efficiency and smooth motion of biped is investigated. Also, we study the behavior of the biped due to a disturbance in the angular velocity of torso.