International Journal of Electrical and Computer Engineering (IJECE) Vol. 11, No. 1, February 2021, pp. 802~814 ISSN: 2088-8708, DOI: 10.11591/ijece.v11i1.pp802-814  802 Journal homepage: http://ijece.iaescore.com Performance comparison between variants PID controllers and unity feedback control system for the response of the angular position of the DC motor Mustafa A. Mhawesh Al-Furat Al-Awsat Technical University, Iraq Article Info ABSTRACT Article history: Received May 11, 2020 Revised Aug 7, 2020 Accepted Aug 17, 2020 This paper proposed a detailed study for the response of angular position of the rotor of a DC motor. It is a comparative analysis to the behavior of the DC motor when the motor is alone and when it is with controllers. Furthermore, a comparison between the responses of controllers themselves. A conventional PID controller which was tuned by using Ziegler and Nichols method was proposed in this paper. Also, Modification PID controllers were proposed in this paper. The modification PID controllers are PI-D controller and I-PD controller. Mathematical calculations were done to get the transfer functions for the DC motor and the controllers. Time domain specifications and figures were obtained for each case by using Matlab program. The obtained results were summarized in tables. This paper determined which the controller is the best one depending on the obtained figures and the time domain specifications. Keywords: DC motor modeling I-PD controller PID controller PI-D controller Ziegler and Nichols method This is an open access article under the CC BY-SA license. Corresponding Author: Mustafa A. Mhawesh, Al-Furat Al-Awsat Technical University, Kufa, Najaf, Iraq. Email: mustafaazzam@atu.edu.iq 1. INTRODUCTION DC motors are commonly used in many uses because it has simplicity and accuracy in control characteristics. It is used in robotic arms, electric trains and cars, steel rolling mills, drones, conveyor belts, and cranes [1-7]. There are a lot of researches were achieved on the speed control of DC motors. Most of them used the PID controller to set the DC motor speed [3, 8, 9]. PID controller is combined from proportional (P), Integral (I), and derivative (D) controllers. Therefore, it is named three terms controllers. When PID controller is used, the response will be good, reliable, and robust [8, 10-12]. The P controller of PID is used to decrease the disturbance effects on the system output. The (I) controller of PID is used to remove steady-state error. The D controller of PID is used to weaken the dynamic response makes the system more stable [2]. PID transfer function is PID =   (1+ 1    +   ) The authors of [2] used conventional proportional integral derivative, genetic algorithm, GA, to modify the PID elements, and a self-tuning fuzzy PID controller to regulate the speed of BLDC motor. The authors of [8] used conventional PID and PI-D control to control a fly-by-wire flight. The authors of [13] used PID controller with friction compensator to fix the exactly angular position of DC geared motor. Moreover, they used the UNO Arduino microcontroller to control the voltage of the brushed Namiki direct