Flexible Bi-modal Control Modes for Hands-Free Operation of a Wheelchair by Head Movements and Facial Expressions

Many kinds of head movements and facial expressions based human machine interfaces (HMIs) have been developed for hands-free control of electricpowered wheelchairs in order to assist disabled and elderly people. Most of these HMIs have a fixed configuration and do not allow users to choose a configuration suitable to their needs. It becomes necessary to provide users with different control modes and flexible configurations. This chapter presents five flexible bi-modal modes for hands-free control of a wheelchair that allow users to choose the most comfortable facial expressions and head movements. An Emotiv sensor is deployed to collect facial expressions and head movements for the bi-modal control modes. Two healthy subjects have participated in experiments, and have chosen their best configurations of the modes for controlling the wheelchair. Experimental results show that bi-modal control modes are flexible and allow users to select their preferred configurations for controlling the wheelchair reliably.