Prototype of a wheelchair controlled by cervical movements

This work presents the development of a motorized wheelchair controlled by cervical movements, where two accelerometers are used as sensors in the definition of movement commands of the wheelchair. One accelerometer is positioned in a helmet on the user's head and the second is positioned on chair base. The use of two sensors has the objective of collecting the signals in differential form providing to system the capability to recognise horizontal plane and slant. The microcontroller STM32F100RB is responsible for processing the signals provided by sensors and for generating the control signals of the wheelchair. Throughout the text are shown the response of accelerometers as a function of the angles of the frontal and transverse tilt of the head, the curves of electric current, the RPM and the efficiency of the transmission system on each wheel as a function of torque, the speed of the wheels as a function of encoder signal frequency and the parameters of the control system adopted. Tests of the wheelchair performance in horizontal and inclined planes were executed and discussed.