Modelling and Controlling of a Hybrid Motorized Wheelchair on Flat and Inclined Surfaces

Abstract

In the world, there are a significant number of people having some type of motor disability. Thus, in recent years, a great number of researches about adaptations on wheelchairs have increased, allowing people with some type of motor disability to live and to interact with society. In this context, a new type of wheelchair, the Hybrid Motorized Wheelchair (HMW), is under development. It has two locomotion systems, a conventional wheel system and another system with tracks, which enables it to transpose obstacles, such as stairs. In this work, a mathematical model for the track locomotion system of the HMW, composed of kinematic and dynamic parts, is presented. In addition, a gearmotor torque control for the tracks is developed, since the torque provides smooth and precise driving. The open-loop and closed-loop control techniques, such as control Lyapunov function (CLF) and Proportional-Integral-Derivative (PID) controller, were designed. Thus, the stability analysis of these controllers, taking into account the occurrence of external disturbances, may indicate which one best assists wheelchair users, providing a safer and more efficient navigation with the HMW. In order to study and to adjust the wheelchair controllers in a simulated environment, the HMW model was implemented in Matlab®/Simulink.