Trajectory Control of a Variable Loaded Servo System by using Fuzzy Iterative Learning PID Control

In this study, trajectory control of the variable loaded servo system is performed by using a Fuzzy Logic based Iterative Learning Control (ILC) method. As the iterative learning control structure, a Iterative Learning PID (IL-PID) Controller is used in the study. Also, a fuzzy adjustment mechanism has been added to the control system for specify the initial parameter of the IL-PID controller. So, with combining the fuzzy based parameter adjustment mechanism and the IL-PID controller, Fuzzy Iterative Learning PID (Fuzzy ILPID) controller is designed to improving the system performance. In the designed system, thanks to the fuzzy adjustment mechanism, the IL-PID controller parameters such as Kp, Ki, and Kd values are automatically adjusted to the appropriate values initially. To illustrate the effectiveness of the proposed fuzzy IL-PID controller, trajectory control of the variable loaded servo system was performed by using both Fuzzy PID and Fuzzy IL-PID control methods under the same conditions separately, and the obtained results were compared. It is seen from the experimental results, the proposed Fuzzy IL-PID control method is to better compensate the system effect as time varying loads and has reduced the steady-state error more than other method in iterations progresses.