Abstract
Autonomous car navigation system based on GPS (Global Positioning System) is a new and promising technology, which uses real time geographical data received from several GPS satellites such as longitude, latitude, speed and course to help navigate a car. The goal of the project is to make a auto-navigational car model that can route through known or pre-programmed co-ordinates autonomously without any human involvement. The project discusses how GPS readings of the current and destination points are used to compute the distance and direction of the destination and thereby navigating the car on the set path. It also discusses how the car must maintain its direction by automatically correcting its course based on new GPS data received. The project discusses various issues that were encountered and solved throughout the course of the project. The project is coded in C, developed and compiled in AVR studio software and is implemented on a Atmel ATmega328 microcontroller. The project utilizes EM408 SiRF Star III/LP single based chipset GPS engine board receiver manufactured by GlobalSat Technology Corp., Taiwan and sold by USGlobalSat Inc, USA. The output of the GPS receiver is a standard NMEA signal which is decoded by the microcontroller to get necessary geographical parameters. Once the microcontroller has the required data, it can compute the direction of movement and thereby navigate the car. Also, the inherent logic steers the car in case the car deviates more than a certain degree from its course. The car that is referred to in this project is 4WD dc-motor controlled robot car.