Umar AzizM. Jurair SaqibBilal Shah2016-04-202016-04-202015https://escholar.umt.edu.pk/handle/123456789/1830DC motors are widely used from toy cars to locomotives, treadmills and industrial conveyors etc. But as the load increase on motor's shaft its speed goes down which is not desired. This is the first propose of this research paper to design a closed loop system that maintains the speed of dc motor to a set point. To achieve this a Proportional Integral and Derivative (PID) controller was used as a compensator which is given the error signal (difference between set point and output of system) to produce a gain then this is used by the Arduino to generate a Pulse Width Modulated (PWM) signal and is given to motor drive to change the time for which power is given to the motor resulting in desired speed of motor with minimum power loss. Now the issue is to tune the parameters of PID controller for best response, this is the second part of the project to chose the best controller PI or PID and then optimally tune the controller to increase efficiency of the system i.e. response of the system (reducing the rise time, settling time, overshoot and steady state error). This optimum tuning was achieved using three different methods including: Rootlocus, Hit and trial and Ziegler Nicholas methods, all these methods were implemented on MATLAB after developing motor model with variable load. The root-locus method was used by changing the position of poles of the open loop step response of the system and then checking the outcome (the rise time, settling time, overshoot and steady state error). Similarly hit and trial and Ziegler Nicholas methods were implemented by changing the values of Kp, Ki, Kd randomly until a stable and robust system was achieved for all three types of controllers i.e. PI, PD, PID, afterwards the response of system for all controllers was compared for all tree methods and best of which was used moreover the parameters of best controller were implemented on hardware and the outcome was reasonably efficient.BS ThesisDC motorsProportional integral and derivativeThesis