Multi-colored line following and obstacle avoiding helicopter

This paper presents a way to build a Multi-colored line following and obstacle avoiding helicopter using 4 infrared sensors. This helicopter is built on an ATmega8 microcontroller which has been programmed using Arduino. It has 1 infra-red sensor (LM358) below it in-between the landing gears, one infra red sensor to its left, one to its right and one at front to detect obstacles. It has 3 DC motors, two at the top and one at the rear. There are 2 H-bridges (L293D) mounted on it to provide the driving mechanisms for the motors. Three DC motors with rated voltage of 3.7V are used. Once the helicopter has been turned on, it rises about 5cms above the ground and goes straight and left until a line has been detected by the sensor. It then starts going straight right until the sensor stops encountering the line. If at all at any point of time any of the sensors detect an obstacle it will stop until the obstacle has been removed. It continues doing this until there is no line to follow in which case it continues going in a straight and left way or it has been brought to rest by switching it off.