Is it possible to localize a robot without any sensors, odometer and servo motors?
Assume robot has dc motors and no obstacles.
If you know the wheel radius and the speed of the robot, you will be able to calculate its location at any time relatively to its initial position.
travelled_distance = Speed * time;
current_position = initial_position + travelled_distance;
This is a simplified 1-dimensional equation than can help you. But keep in mind that without sensors and odometry the localization can't be very accurate.