It is estimated that, disabled and elderly people who need a wheelchair are to be over 100 million worldwide. A lot of these disabled cannot use the traditional wheelchairs as users may have restricted limb movements. Many alternative control methods have been developed.Even though, the eye tracking control offers a more natural mode to guide the wheelchair, it is omitted because users are normally not allowed to look around during motion. The aim of our project,WheelChair Motion Control Using Eye Gaze and Blinks is to develop a new method that allows the user to look around freely while the wheelchair navigates automatically to the desired goal point.
Traditional electric-powered wheelchairs are normally controlled by the users via joysticks, which cannot satisfy the needs of elderly and disabled users who have physical disabilities caused by some diseases such as parkinson's disease and quadriplegics. Recently, many alternative control methods have been suggested such as voice recognition and guidance, vision based head gesture control, eye tracking control, and face figure based control. Most of these controls provide a more natural mode of interaction between a human and a wheelchair, but also require the user to be concentrated during motion due to safety reasons. It may make the user uncomfortable. It can also lead to false triggering by the unintentional face or eye movements made by the user.
The main aim of this project is provide a hands-free control system which utilizes eye gaze and blinks to control an electric powered wheelchair. From the gaze angles, the controller calculates the goal point direction and distance. As the goal point is calculated,the wheelchair navigates automatically to destination. An encoder is used to know the distance traveled. The path may not be clear always. If the path is not object free, it uses Point bug algorithm to navigate towards the target. A range sensor output is used to find the distance to nearest obstacle in any direction. Thus the user can look around the surrounding environment freely during the navigation process in this automatic mode.
Power wheelchairs play a significant role in the rehabilitative activities. Many of disabled persons use power wheelchairs to navigate in their residential, institutional or official area, in order to communicate with their society more conveniently. Although today's various control interfaces and microprocessor's usage make it easier to navigate a wheelchair, persons with severe and multiple disabilities may yet find it extremely difficult to steer a power wheelchair in their favorite directions and with an ideal quality. The aim of the intelligent wheelchairs is to make wheelchairs able to be controlled and navigated with the minimal interaction with the users, in order to enhance the quality of service for the handicapped. The methods used for commanding in these intelligent wheelchairs are head or chin control,eye gaze, tongue pad, head, hand and foot switch control. In addition to easy transferring of command to the system, users need to conform motion quality according to their physical abilities.
The goal of Human Computer Interface (HCI) is to provide humans with a new communication channel that allows translating Humans will states via a computer into application specific actions and here wheelchair control. A study on the group of persons with severe disabilities shows that many of them retain intact their control capacity over the oculomotor system, so eye movements could be used to develop new human-machine communication systems. Furthermore, this type of interface would not be limited to severely disabled persons but could be extended to the whole group of persons with the capacity for controlling their eye movements.
The present technologies in this field make use of the direction of eye for wheelchair motion at that specific instant. So the motion towards a distant point to which direct path not available, will require the user to be focused throughout motion. The user is not allowed to look around the environment while in motion. If we are able to acquire the direction and distance to the destination point initially itself, the motion can be made automatic,which gives a more user friendly interface.The main motive behind this project has therefore been the aim of making a contribution towards satisfying the technological needs of wheelchair users by designing an eye or facial movement guidance system for severely disabled persons, with an economic and functional feasibility that would enable them to improve their quality of life.