Biped Robots: The State of Art

Abstract

-Researchers from all over the world have studied biped robots. The robots have an inherently unstable structure and whose modeling and control can be carried out by different techniques. The aim of this study is to present a critical literature review of the main types of biped robots developed until the present date, including Brazil. According to their particular features presented in the literature, robots will be treated concerning dimensions, degrees of freedom or system of control. Advantages and disadvantages of moving robots when compared to leg robots will be presented. This comparison will also be done taking into account other types of robots. The evolution of biped robots also will be presented including those ones for entertainment purposes. Mathematical modeling for determination of equation of motion, Zero Moment Point, and application of control theory in order to allow a response for a standard input is also showed. KEYWORDS. Biped robots, state of art, robotics review. INTRODUCTION The aim of this review is to keep the knowledge on biped robots up to date, in order to allow the knowledge of the main research carried out through and in progress in the world-wide context of this area. The main objective of this work is the presentation of the biped robots that have most contributed for the state of art and the application or development of new theories of control or locomotion. A brief review of the main robots developed in Brazil is also presented. The methods of locomotion on the ground include tracks, wheels and legs. The legged motion has the peculiar characteristic of discontinuous contacts with the ground, which allows to avoid obstacles, walk in an uneven ground and climb stairs. While wheel robots require a continuous path of support, legged robots can cross in a terrain that is discrete and discontinuous. As an example, humans can walk not only on flat surfaces 371