Designing and Analysis of Advanced Fractional Order Controller for Pitch Control of Air Craft System

Abstract

The combination of nonlinear dynamics, modelling uncertainties and parameters variation in characterizing are major problem in aircraft. Three rotations Roll, Yaw and Pitch can be controlled by using Aileron, rudder and elevator. The control system of aircraft can be divided into two parts which are longitudinal and lateral control. Pitch control is a longitudinal problem which is used to design autopilot. To achieve better result, for such critical control scheme, Fractional Order Proportional Integral Derivative control FOPID, Fractional Order Of [Proportional Integral Derivative] FO[PID] control are proposed in this thesis work. These controllers are compared with conventional order controller. Zeigler-Nichols Tuning proves to be more effective in giving accurate results. The main function of designing fractional order controller is to determine the two parameter λ and μ apart from the usual tuning parameters i.e. Kp, Ki and Kd of controller. Both the parameters λ and μ are in fraction order controller, increase the robustness of the system and gives an optimal control because λ is in the integral action and μ is in derivative action so it improve the response in fraction. From the results and graphs of FOPID controller gives better response than conventional order controller. There is improvement in control parameters with rise time improved by 0.0792 seconds, peak overshoot by 0.1873 %, settling time improved by 0.099 seconds, ISE,IAE and ITAE is 0.0068% ,0.008% ,0.0751 % decrease respectively . The control parameters of FO[PID] controller is improved as compared to FOPID controller with rise time 0.0791 seconds, peak overshoot by 0.0353%, settling time with 0.0989 seconds and ISE , IAE by 0.1605% ,0.0035% decrease respectively. There is a improvement in the control parameters of FOPID controller as compared to conventional PID controller with rise time 0.1583 seconds, peak overshoot by 0.2226%, settling time with 0.1979 seconds, ISE, IAE and ITAE by 0.1673% , 0.0117% 0.0322% decrease. As first order disturbance in the system, the FOPID Controller gives better response then conventional order controller. The value of rise time and Settling time is 1.3698 and 0.7232 second decrease, IAE values 0.0028% decrease but ISE and ITAE values 0.3113 and 0.5708 are increase respectively. As compare to FO[PID] control to conventional order PID controller the rise time is decreased by 1.4843 second, settling time is decreased by 1.3583 second and ISE, IAE and ITAE is increased by 0.2804% , 0.4474% and 0.3215%.