Design & Development of an Automated Wheelchair for differently abled person using Keypad & Bluetooth Technology

This paper mainly focuses on the design and development of a low-cost automated wheelchair for the patient or patient attender or differently abled person. The entire system is designed based on 24 V operating voltage. The various components/modules such as Permanent Magnet DC motors (PMDC motor), linear actuators, H bridge DC-DC chopper, DC voltage regulator, Microcontroller, keypad, and Bluetooth modules are selected as per the design. An eight-channel relay module is used as an H bridge circuit for linear actuator movements in order to move the left leg footrest, right leg footrest, and back supporting rest independently. Simulation of four quadrant chopper is carried out with an equivalent PMDC motor load to analyze the electrical parameters such as switching pulses, voltage across motor & current drawn by the motor using the MATLAB/Simulink software package. The hardware modules are mounted on the wheelchair and coupled to two PMDC motors and six linear actuators. The input voltage across the motor and current drawn by the motor are recorded using a power quality analyzer HIOKI PW3198 model. The waveforms and results obtained from the simulation of the power converter are in conformation with the hardware results obtained. The navigation mode, left leg footrest, right leg footrest movements, and reclining of the wheelchair are tested independently by using a switch selector to choose either keypad mode or Bluetooth mode and found to be successful with respect to the features considered for the design of the automated wheelchair.