This is nice project made by Ibrahim Kamal. His aim was to create robot which navigates by using its position data log. The hardest thing was to record distance and turning angle because of these parameters depends how precise robot is manoeuvering from reference point.
Author provides really good theory analysis of dead reckoning process and how this was transferred to 89C52 microcontroller which counts encoder disc pulses for distance and controls steering motor which controls the angle of robot turning. Also all operation data is displayed on 2x16LCD module.