Biped Robots: Effects of Small Perturbations on the Generation of Modular Trajectories

Humanoid robots have been extensively studied in the last few years. The motivation for this study is that bipedal locomotion is superior to wheeled approaches on real terrain and situations where robots accompany or replace humans. Some examples are, on the development of human assisting device, such as prosthetics, orthotics, and devices for rehabilitation, rescue of wounded troops, maidens, accompany and assistance to elderly people, amongst others. Online generation of trajectories for these robots is a complex process, that includes different types of movements, i.e., distinct motor primitives. In this paper, we consider two motor primitives: rhythmic and discrete. We study the effect on a bipeds robots’ gaits of inserting the discrete part as an offset of the rhythmic primitive, for synaptic and diffusive couplings. We also study stability of biped gaits. We simulate a periodic solution corresponding to the biped run, for the variation of the discrete offset. We find that amplitude and frequency of this periodic solution, are almost constant in all cases studied. This is useful when considering implementations of the proposed controllers for generating trajectories for the joints of real biped robots. c © 2012 European Society of Computational Methods in Sciences, Engineering and Technology