A SYSTEMATIC GAIT-PLANNING FRAMEWORK NEGOTIATING BIOMECHANICALLY MOTIVATED CHARACTERISTICS OF A PLANAR BIPEDAL ROBOT

Abstract

Natural human walking possesses three characteristics: (i) gait repeatability, (ii) postural balance, and (iii) highly regulated centroidal angular momentum (CAM). In this paper, a systematic gait-planning framework is presented for the gait planning of a five-link bipedal robot, negotiating those three characteristics. The framework employs a set of task-space variables and a set of gait parameters. Five kinematic and dynamic objective functions are selected, corresponding to the biped's five degrees of freedom (DOFs), incorporating three characteristics. Fusing the equations of five objective functions together, two ordinary differential equations called the framework equations are derived. Assigning desired values to the gait parameters, the framework equations are integrated across the gait cycle, rendering the motion profiles of the task-space variables. A set of simulation results shows that the framework presents gait that successfully negotiates three characteristics. A parametric analysis is then carried out to study the effect of changing the gait parameters on the joint angular displacements and velocities, the postural balance, and the regulation of CAM of the bipedal robot.