Modeling and simulation of stable human locomotion using five degree-of-freedom gait model

Abstract

Human locomotion involves a highly sophisticated and complex locomotive system. In order to understand how models of such system are built, it is useful to consider the meaning and implication of modeling and simulation as an attempt to represent reality. The great number of its components as well as the variety of its possible motion patterns makes the modeling of such apparatus and the simulation of its movements a very challenging task. The biomechanical modeling of human locomotion has been done in the past using a variety of approaches. One such is the application of a conventional non-linear feedback controller to human walking, i.e. gait synthesis using feedback controller. Since human gait follows a specific trajectory with pre-defined step width, height and period, its synthesis can be replicated by defining the gait parameters, such as orientation and position, as functions of time. The motion of the human includes two stages (single support phase and double support phase). This proposed scheme simulates a two-dimensional, three-link and single joint planar inverse locomotive model for the both the phases. The simulation of human gait done using the model developed provides the control signal in each stage of the walking. The inverse dynamic model is used to determine the joint positions and forces at each instant and the controller determines the actuation to be provided for the gait to follow the desired trajectory.