I want to share my robot with you. it was made in 2006. Its name is TERMIT. The TERMIT is a mine searching and exploratory robot and is studied with solar energy. It's fully autonomous and remote control. The robot uses 6 dc motors to move the wheels, camera and robot arm. I used one pic16f877 and pic16f628 and RF module. I've used several mosfet for motor drives. To avoid obstacles, there are five IR-sensors that give a picture of what the robot is approaching. From that information the robot decides if it should go to the left or the right. And if this robot detects a mine, it will transmit a signal to control center.
The four wheels of Termit have encoders. With those encoders Termit can save and transport the data of the path and also the coordinates of the founded points. The coordinate system of the Termit is an x-y system with a reference point that was taken from Termit's start point. I couldn't have the opportunity of using GPS system so I've tried to perform a basic mapping system with little deviations which can be caused by the encoders. The suspension system is very special for me because I did it by myself. Every parts of Termit was handmade.
You can watch its videos from http://www.robotiksistem.com/kesif_robotu_termit.html