Electric Wheelchair
Overview of the project
The aim of this project is to modify a manual wheelchair to an electric one in the easiest way possible. In Eritrea, there are a lot of manual wheelchairs where as a few electric ones. This is because electric wheelchairs are quite expensive. This project aims to make cheap wheelchair available in the market in such away people with disability can afford them.
Application
This project offers a relief to physically challenged people with a much better mobility at a price they can afford The war disabled Eritrean veterans’ manual wheelchairs could be modified to electric ones, giving them more self independence.
Block diagram
In order to change the manually operated wheelchair to an electric one, a DC electric motors at the rear wheels of the wheelchair. These motors take power supply from a battery source fixed below the wheelchair’s seat. An h-bridge circuit controlled by a PIC micro controller. This PIC takes input from a joystick.
Circuit Diagram
This project uses two car’s wiper dc motors. The reason was that they were the ones that we could easily available and are affordable also. PIC micro controller (PIC16f877A) is used to produce two PWM signals. Moreover, it’s an efficient and powerful micro controller which is easy program. It also used a regulator to change the 12v battery voltage to 5v supply input for the Joystick, micro controller and driver IC.
Flow chart
The prototype
When the joystick gives positional signals to the controller according to the given position of the joystick, the motors move in that direction at a certain speed. For the turning operation, when the joystick is moved left for instance, the left motor slows down while the right motor goes with a constant speed. Thus the motor turns to the left. This turning operation is similar of a tank and can be compared to it for a better understanding
Conclusion
In comparison with the modern wheelchairs available in the market, this modified one is less expensive. With the proper selection of materials and adjustment, the price of a modified electric wheelchair could be reduced to half of the modern wheelchair available in the market.
