Modeling and path-following control of a wheelchair in human-shared environments

Abstract

This work presents the kinematic and dynamic modeling of a human-wheelchair system which considers that its center of mass is not located in the middle of the wheel's axle. Furthermore, a novel motion controller is presented for a human-wheelchair system, which is capable of performing positioning and path-following tasks in human-shared environments. This controller design is based on two cascaded subsystems: A kinematic controller, and a dynamic controller that compensates the dynamics of the human-wheelchair system. Additionally, an algorithm based on fuzzy-logic is proposed and incorporated in the aforementioned path-following control for pedestrian collision avoidance. This methodology considers to quantify heuristics social rules to make a balance between modulating velocity or direction during the avoidance. Three different interference cases, commonly found during walking events, are tested in a structured scenario. The experimental results demonstrate that the system is capable of overcoming many usual interference situations with human obstacles. A good performance of the path-following control is also verified.