16. CONCLUSION
At the end of the project phase 2 scheduled in the 8th semester what we have is a prototype which can be controlled with 1) Accelerometer 2) DTMF decoder 3) Control over internet 4) Joystick 5) Chin and 6) Voice. The perception system has been installed successfully, with an aim of detecting an obstacle in any close proximity of the wheelchair using sensors. Also the sensors are being used for detection of elevation and depression .The basic utilities like battery level indicator, urine bag indicator and organizer (reminders, schedules, mobile charger and alarms) have been incorporated. All programs are written and are functional on PYTHON3.The motors of the prototype draws power from the raspberry pi. Raspberry Pi can be powered using an adapter (5V 750 -1250 mA) or using a battery of the same rating, the motors are driven by a motor driver IC (L293D).The control signals to this IC is given according to inputs from the respective device. The Raspberry Pi hosts a web server (WebIOPi) through which control to Raspberry Pi from the website is given. In the coming future we have to integrate all the modules to run in 1 program. Different programs have to be written which gives master control of the chair to patient or the caretaker or anybody else considering all the use cases and demand of the patient.
The mechanical department is ready with the wheelchair hardware. The motor requirements are being evaluated. The control modules will then be incorporated on the wheelchair. The Department of computer science students have made a dedicated application for the wheelchair which can be downloaded on any android smart phone.
On the actual wheelchair there is a need for feedback mechanism which measures the speed of the wheel and sends the corresponding signal to the Raspberry Pi this mechanism is needed so that if one wheel stops moving due to a physical restraint Raspberry Pi continues to supply power to the wheels which can lead to disastrous situations, hence the feedback mechanism ensures the speed and the stability of the wheel , apart from this we the programs written for the prototype needs to be modified to include speed control of the DC Motor, this is a simple task as we already have the Motor Driver for the DC motor it is only a matter of giving PWM signal to the Motor driver. Internet control has to be perfected and security has to be provided against hacking.
As of now the website runs on WebIOPi server, separate server and domain name has to be purchased. Database has to be made for patients’ medical record and put online so as to give access to different users of the website. Robust construction has been made around the Raspberry Pi to protect it from external influences.
Power distribution has to be made to different modules. Functionality of the wheel chair should be increased by including the indoor mapping and the vital signs monitor which is developed needs to be mounted on to the Raspberry Pi.
As Raspberry Pi has SPI and I2C interfaces through which any number of sensors can be added. Eight MCP23017 port expander IC’s can be connected to Raspberry pi, with each IC accommodating 16 GPIO pins. This makes a total of 128 expandable GPIO pins. This is an advantage because any future requirement can be taken care of using the same controller
Thus, we have achieved mobility control of the wheelchair using our master controller. All these features make our wheelchair truly smart.