Design Methodology for Biped Robots: Applications in Robotics and Prosthetics

Abstract

Bipedal walk as an activity requires an excellent sensorial and movement integration to coordinate the motions of different joints, getting as a result an efficient navigation system for a changing environment. Main applications of the study of biped walking are in the field of medical technology, to diagnose gait pathologies, to take surgical decisions, to adequate prosthesis and orthesis design to supply natural deficiencies in people and for planning rehabilitation strategies for specific pathologies. The same principles can also be applied to develop biped machines; in daily situations, a biped robot would be the best configuration to interact with humans and to get through an environment difficult for navigation. If the biped robot is designed with human proportions, the robot could manage his way through spaces designed for humans, like stairs and elevators, and hopefully the interaction with the robot would be similar to interaction with a human being. The National University of Colombia has been working on the design and control of biped robots, supported by two research groups, Biomechanics and Mobile Robots. The joint effort of the groups has produced three biped robots with successful walks, based on a single idea: if an appropriate design methodology exists, the resulting hardware must have appropriate dynamical characteristics, making easier the control of the walking movements. The design process successfully merges two lines of research in bipedal walk, passive an active walks, by using gait patterns obtained thanks to the simulation of a kneed passive walker to create the trajectory followed by the control of an active biped robot. Our actual line of research in biped robots is to use biped robots reproducing the human gait pattern as engineering tools to test the behavior of below-knee prostheses, thus producing a biped robot with heterogeneous legs that allows the evaluation of how the prosthetics influence the normal gait of the robot while it is walking as a human.