International Journal of Electrical and Computer Engineering (IJECE) Vol. 10, No. 3, June 2020, pp. 2285~2295 ISSN: 2088-8708, DOI: 10.11591/ijece.v10i3.pp2285-2295  2285 Journal homepage: http://ijece.iaescore.com/index.php/IJECE Variable speed control for 2Ph-HSM in RGS: a comparative simulation study Salam Waley Shneen, Mohammed Qasim Sulttan, Manal Hadi Jaber Energy and Renewable Energies Technology Center, University of Technology, Iraq Article Info ABSTRACT Article history: Received Jun 12, 2019 Revised Nov 24, 2019 Accepted Dec 1, 2019 There are many applications of two-phase hybrid stepping motor (2Ph-HSM) system. The robotic grinding system (RGS) one of these applications. In this work, under the title variable speed control. The aim is Simulink the 2Ph-HSM in RGS with a proportional-integral controller (PIC) and optimization unit such as Genetic Algorithm (GA) which tuning PIC as (GA_PIC) to improve the RGS action by improving the parameters of PIC. Also comparing the act of PIC and GA_PIC to see which state is the best. The simulation results of this work show the GA_PIC is the best that comparative with PIC. Keywords: 2Ph-HSM GA GF PIC RGS Copyright © 2020 Institute of Advanced Engineering and Science. All rights reserved. Corresponding Author: Salam Waley Shneen, Energy and Renewable Energies Technology Center, University of Technology, 52 Industry street, Baghdad, Iraq. Email: salam_waley73@yahoo.com & 50054@uotechnology.edu.iq 1. INTRODUCTION The two-phase hybrid stepping motor (2Ph-HSM) system one of the machine drive system (MDS) that can be using in robotic grinding system (RGS) [1]. The proportional –integral controller (PIC) [2, 3] one of the classical controllers that can be using with MDS. The Genetic Algorithm (GA) [4-6] one of the optimal controller system that can be using with MDS [7]. This work uses Matlab to simulate the RGS including, 2Ph-HSM, control unit PIC and optimal controller system GA. RGS is a promising technicality to generate the final form of the required design. It can keep the human from taking part in noisy and dirty environments, get better product quality, and slash production expenses [8]. Some fieldwork formerly showed a difficulty in grinding the complicated form in workpiece like a marine propeller or turbine blade which requires the end-effector of a manipulator to hold over a stable connect force with the environment while the grinding tool moving along the workpiece. To carry out such a job and at the one time, both the strength and location of the robot should be controlled. Those control systems were classified into two major strategies, hybrid control for the force/position, and impedance control. Those strategies need a careful dynamic pattern of the manipulator and interaction of contact strength. In a strategy of a hybrid control for force/position, only natural trend path is undergoing a constant pressure or strength control, and this has some advantages like, the first is the dimensional change is compensated automatically because of the tool corrosion, and second is the accuracy on the planned path is relaxed since the confirmed connect from the strength control loop will offset the program error [9]. The PIC is a conventional controller and commonly used in many industrial processes. In the practical field, the hardware systems have non-controllable properties like the high order and non-linearity, so the good methods of PI tuning are more suitable from other methods. The PIC performance can be determined by many methods such as trial and error method, Ziegler –Nichols numeral method and the development mechanisms