Multimodal Control of an Intelligent Wheelchair (Commande Multimodale d’un Fauteuil Roulant Intelligent).

Abstract

An intelligent wheelchair (IW) is a standard electric wheelchair (EW) to which a computer and a collection of sensors have been added, giving the user, who cannot use the usual joystick, the ability to control it without touching any physical device. In the recent years, several research projects around the world have been focused on the development of IW prototypes. However, the adaptation of their user interface to the patient’s abilities is often a neglected research topic. The majority of the interfaces are adapted to a specific user group. This thesis presents the design and implementation of a multimodal control system for IW to assist people with different levels of disabilities. The system is composed of an EW equipped with necessary electronics (microcontrollers, sensors, laptop, microphone and camera) to ensure safe mobility and ease of operation. In order to control the movement of the wheelchair, firstly, one of the control modes (manual, vision based method, sensors based method, or speech based method) is selected by the user according to his/her abilities. Then, depending on the controlling command (Forward, Backward, Right, Left, or Stop) the microcontroller generates specific signals to emulate the joystick for monitoring the control board of the wheelchair. The principal advantage of the proposed system is that the switching between the control modes is soft, straightforward and transparent to the user. The experimental tests applied to this wheelchair in real environment, proved the feasibility and efficiency of our multimodal system.