@berkeman I am sorry for not giving the exact topic of my mini project. Actually i am new in the physicsforum. I am suppose to submit mini project as an electronic project and its free to choose your own project. So, i have decided to make a robot(car) which has following characteristics:
1)Signal Following application: It will move towards the transmitter.
2)Obstacle avoidance: If any objects come in front, it just change its direction and again move towards the signal
3)And i am using a fuzzy logic to control the speed of the motor.
I had a doubt as i explained earlier that how actually can a robot detect the direction of the signal, radio wave and micro wave spreads and the intensity is not essential that is high for the direction it is coming. Many suggested me to use, directional antenna and PID for the signal following characteristics. I am thinking of SONAR system. It would be a great help if you suggest me about what to do exactly in this transmission and reception of signal with direction detection.