Introduction
In today’s time, an estimated 1% of the world’s population needs a wheelchair. An increased percentage of elderly and disabled people who want to enhance their personal mobility, for them wheelchair is the best assistive device. A disabled or an invalid individual (usually the disability of the lower part of the body) can find it convenient to move around and maneuver using the help of a chair constructed on wheels which can either be pushed by another individual or propelled either by physical force or electronically. Such a chair is called as a Wheelchair.
Traditional wheelchairs have some limitations in context to flexibility, bulkiness and limited functions [1]. Our approach allows the users to use human gestures of movement like hands and synchronize them with the movement of the wheelchair so that they can use it with comfort and ease on all kinds of terrains without the hurdle or cardiovascular problems or fatigue.
Some existing wheelchairs are fitted with pc for the gesture recognition [2]. But making use of the pc along with the chair makes it bulkier and increases complexity. This complexity is reduced by making use of the MEMS accelerometer [3-4], the size of which is very compact and can be placed on the fingertip of the patients.
Other existing systems, which make use of the similar kind of sensors are wired, which again increases the complexity of the system. They also limit the long range communication. This complexity is removed by using the RF transmission. Signals through RF travel larger distances. Irrespective of line of sight communication, signals through RF travel even when there is obstruction between the transmitter and receiver.
This paper proposes an integrated approach to real time detection, tracking and direction recognition of hands, which is intended to be used as a human-robot interaction interface for the intelligent wheelchair. This paper is to demonstrate that accelerometers can be used to effectively translate finger and hand gestures into computer interpreted signals. For gesture recognition the accelerometer data is calibrated and filtered. The accelerometers can measure the magnitude and direction of gravity in addition to movement induced acceleration. In order to calibrate the accelerometers, we rotate the device “sensitive axis with respect to gravity and use the resultant signal as an absolute measurement. Integrating a single chip wireless solution with a MEMS accelerometer would yield an autonomous device small enough to apply to the fingernails, because of their small size and weight. Accelerometers are attached to the fingertips and back of the hand. Arrows on the hand show the location of accelerometers and their sensitive directions, that the sensitive direction of the accelerometer is in the plane of the hand.
The gesture based wheelchair is suitable for the elderly and the physically challenged people who are unfortunate to have lost ability in their limbs due to paralysis or by birth or by old age. Elders find it tough to move inside the house for day to day activities without help or external aid. Our proposed system makes use of a wheelchair that can be used by elderly or physically challenged to move inside the home without difficulty and without external aid. The elders may also forget the way to the different rooms in house due to the increase in forgetfulness as they become older. The physically challenged, find difficult to move the wheel chair without help from others. By making use of the system, the elderly and the physically challenged can go to different rooms in the house like kitchen, living room, dining room etc. by just showing a gesture which is predefined to that particular room. It is also a virtue of the system that even the foot can be substituted in place of the hand for users who might find that more convenient.
The aim of this project is to controlling a wheel chair and electrical devices by using MEMS accelerometer sensor (Micro Electro-Mechanical Systems) technology. MEMS accelerometer sensor is a Micro Electromechanically Sensor which is a highly sensitive sensor and capable of detecting the tilt. This sensor finds the tilt and makes use of the accelerometer to change the direction of the wheel chair depending on tilt. For example if the tilt is to the right side then the wheel chair moves in right direction or if the tilt is to the left side then the wheel chair moves in left direction. Wheel chair movement can be controlled in Forward, Reverse, and Left and Right direction along with obstacle detection using ultrasonic sensor. Automation is the most frequently spelled term in the field of electronics.
The hunger for automation brought many revolutions in the existing technologies. One among the technologies, which had greater developments, is the MEMS accelerometer sensor. These had greater importance than any other technologies due its user-friendly nature. MEMS accelerometer sensor based devices can be easily reachable to the common man due to its simpler operation.
Wheel chair is the best assistive device used by elder and disabled people. The driving and controlling of traditional wheel chair are much harder task. Our aim is to build a low cost and powerful wheel chair which helps the handicapped people to travel without depending others. Introducing a prototype of cost effective electronic gesture based wheel chair. Easy to operate, because this wheel chair can operated even by a user without palm.
- NEED OF PROJECT
This project to develop a wheel chair control which is useful to the physically disabled person with his hand movement or his hand gesture reorganization. With the help of the wheel chair physically disabled person would able to move himself to the desired location with the help of hand gestures which controls the movement of the chair. This project aims to provide a feasible solution to those handicapped people who do not have the ability to maneuver the wheelchair by themselves. These include people with serious paralytic condition. Wheelchair automated control systems proved to be versatile tools for many problems in human-computer interface systems. Basically, they are used for providing better usability of a computer or a system for people, including disabled people.
Project idea of Accelerometer based Hand Gesture Controlled Wheelchair
Block Diagram – Accelerometer based Hand Gesture Controlled Wheelchair