Investigation of the performance of fractional order PID controllers on different types of electromechanical systems

In this thesis, the performance of a fractional-order proportional-integral-derivative (FOPID) controller was analyzed and compared with that of a PID controller by conducting various control applications on different types of electromechanical systems, both in simulation environments and in real-time. Initially, the speed control of a direct current (DC) motor was performed using both controllers in simulation and real-time environments. Subsequently, the position control of a planar three-degree-of-freedom (3-DOF) parallel robot manipulator with three revolute joints (3-RRR) was carried out in a simulation environment using both the PID and FOPID controllers. Additionally, liquid level control of a two-tank system for Tank 1 was implemented using both controllers in simulation and real-time environments. To enable the speed control of the DC motor, the electromechanical modeling of the permanent magnet direct current motor (PMDCM) used in the real-time application was performed, and its transfer function was obtained. Following this, the kinematic analysis of the planar 3-DOF 3-RRR parallel robot manipulator was conducted, and the joint angles required to reach the reference position were determined through inverse kinematics analysis. Furthermore, the mathematical modeling of the two-tank liquid level system was carried out, and the transfer functions of the system was derived. The control of these electromechanical systems was implemented in the MATLAB/Simulink environment. Based on the data obtained from the experiments, the PID and FOPID controllers were compared in terms of settling time, rise time, peak time, overshoot, and steady-state error. The results of this comparison indicated that the FOPID controller demonstrated superior performance compared to the PID controller due to its broader control parameter space and better adaptability to system dynamics.