Karary University COLLEGE OF GRADUATE STUDIES AND SCIENTIFIC RESEARCH Robust Control Systems of Temperature A Thesis Submitted to the College of Graduate Studies and Scientific Research in Partial Fulfillment of the Requirements for the Degree of M.Sc in Electrical Engineering (Control) By: Ebrahim Ali Mohammed Alzalab Supervisor: Ust. Abdullah Salih Ali 1436/ / 2015 /7 / Abstract. The majority of control loops in the process control industry use a Proportional-Integral- Derivative (PID) controller. PID controllers have a simple structure that makes controlling the process output simple. Process industries need design methods that lead to the most efficient and successful operation of PID controllers. Robust control is a relatively new addition to the field of control engineering, and it focuses on achieving system robustness in the face of uncertainty. In this paper, a system is robustly stabilized using a graphical design approach for obtaining the full spectrum of PID controller gains. Keywords: PID controller, Robust control, simulation, Cascade gain, Robustness 1. Introduction The plant model is an erroneous depiction of the physical system because Unmodeled dynamics, unmodeled time delays, changes in equilibrium point, sensor noise, and unpredicted interference