DESIGN OF DIRECT ITAE BASED MRAC AUGMENTED FUZZY AND FUZZY-PD PLUS INTEGRAL CONTROLLER FOR POSITION CONTROL SYSTEM

Abstract

A new Model Reference Adaptive Control (MRAC) based on minimizing Integral Time Absolute Error (ITAE) model criterion has been designed. However, an obvious challenge to the performance of the ITAE-MRAC method is poor rise time and settling time in positioning control of dish antenna. Thus, Fuzzy Logic Controller (FLC) and Fuzzy-Proportional Derivative plus Integral (Fuzzy-PD+I) controller were designed. The primary purpose of this work is to use intelligent based multi-loop control strategy to achieve efficient positioning control for satellite antenna. Two control strategies were proposed by separately integrating ITAE-MRAC model with FLC and Fuzzy-PD+I controllers. This resulted in multi-loop control systems in which the ITAE-MRAC model forms the outer loop whose output based on the adjustment mechanism was used to adjust the control dynamic of the inner (or secondary) loop controller (FLC or Fuzzy-PD+I). The use of multi-loop makes the inner loop more stable and efficient in providing improved tracking response to setpoint signal. The control models based on PID, ITAE-MRAC, FLC, Fuzzy-PD+I, ITAE-MRAC-FLC, and ITAE-MRAC-Fuzzy-PD+I were separately applied to the dish antenna positioning system. The results obtained from the controllers indicated that the rise times and settling times were improved including good overshoots respectively with zero steady-state error in all cases. The percentage improvement over FLC and Fuzzy-PD+I revealed 30% and 4.95% reduction in rise times and 22% and 1.62% reduction in settling times using ITAE-MRAC-FLC and ITAE-MRAC-Fuzzy-PD+I, respectively. Generally, the results indicated that the use of the ITAE based MRAC model enhanced the performances of the FLC and Fuzz-PD+I, and the overall transient and steady-state response dynamic characteristics of the dish antenna positioning system.