A PID Controller has been designed and incorporated into the Robot based Agricultural System.This system comprises a Robotic Vehicle which navigates through the field in the desired direction performing tilling or de-weeding as it moves. The PID control system has been designed for automatic steering and speed control of the Robotic Vehicle. The PID control system continuously checks and corrects the direction of travel to keep the vehicle on the desired track.PID Control equations for Discrete Time Domain have been derived and validated by using MATLAB. Functional tests were carried out using ModelSim. The hardware results were finally validated using MATLAB again.The direction accuracy achieved is better than 0.01%.