Design Of Fractional Order PI Controller Research Articles

An analytical solution of fractional order PI controller design for stable/unstable/integrating processes with time delay

This paper aims to put forward an analytical solution for tuning parameters of a fractional order PI (FOPI) controller for stable, unstable, and integrating processes with time delay. Following this purpose, the analytical weighted geometrical center (AWGC) method has been extended to the design of fractional order PI controllers. To apply AWGC, the stability equations of the closed-loop system are written in terms of process and fractional order PI controller parameters. With the proposed method, the centroid can be calculated analytically, and the controller parameters can be easily calculated without the need of repetitive drawings of the stability boundary regions. Additionally, analytical equations are derived to calculate fractional integral order, ?, using the integral of squared error (ISE) objective function. The proposed analytical equations are simple and time-saving which might attract controller engineers for applying them on the industrial level. To show the efficiency of the suggested method compared to the given methods in the literature, several simulation examples are considered. Comparisons between the reported methods are figured out in terms of unit step responses for nominal and perturbed cases. Also, rise time, settling time, maximum sensitivity (Ms), integral of squared error (ISE), and total variation (TV) values are considered to compare the performance and robustness issues. Also, a real-time application of an inverted pendulum setup is deemed to prove the feasibility of the suggested method.

Fractional Order PI Controller Design for Time Delay Systems

This paper aims to look into the fractional PI controller design for a closed loop system having a plant with time-delay. The ultimate frequency of the system is found using a relay auto tuning test and then the parameters of a PI controller are estimated using this frequency in the Ziegler-Nichols (Z-N) tuning formula. These parameters are then used for a fractional order PI controller and the effect of varying the fractional integrator order (λ) of the PI controller on the closed loop step response is examined. Finally, for a given example, the table that includes specifications of the control system for different λ values has been obtained and according to the desired specifications, optimum fractional order PI controller is designed. The presented results are illustrated with some examples.

Fractional Order PI Controller Design for Non-Monotonic Phase Systems

Abstract In this paper, a fractional order proportional-integral (FOPI) controller is proposed for controlling the non-monotonic decreasing phase DC-buck regulator system. The parameters of FOPI controller are optimized by Nelder's-Mead (NM) method. The FOPI controller provides fast closed-loop performance as well as improves the robust properties of the system in time and frequency domain. The controller preserves the monotonic phase between the desired bandwidth and improves the characteristic performance of the system. The proposed method is validated by comparing the time domain as well as frequency domain characteristics with the integer order proportional-integral (IOPI) controllers tuned using various techniques.

Fuzzy Fractional Order Proportional Integral Controllers for UAV Lateral Attitude Control System

This article is based on the theory of fractional calculus control, and put forward a kind of fractional order PI controller design method for lateral attitude control system of unmanned aerial vehicle (UAV) model. And the unit step response of the control system is analyzed in the simulation to improve the UAV flight control system stability and robustness. Use the controller parameter tuning method and combined with fuzzy reasoning to design IOPID controller, FOPI controller and fuzzy fractional order PI controller. Then, by exploiting Matlab, the frequency domain response and unit step response characteristics of the different control systems can be plotted. The results verified that the designed fuzzy fractional order controller for the attitude control system is effective.

Roll-channel fractional order controller design for a small fixed-wing unmanned aerial vehicle

Low-cost small unmanned aerial vehicles (UAVs) attracted researchers and developers around the world for use in both military and civilian applications. However, there are challenges in designing stable and robust flight controllers that handle the UAV model and environmental uncertainties. This paper focuses on the design and implementation of a roll-channel fractional order proportional integral ( PI λ ) flight controller for a small fixed-wing UAV. Time domain system identification methods are used to obtain a simple auto-regressive with exogenous input (ARX) model of the UAV roll-channel. A new fractional order PI controller design method is introduced based on the identified simple model. The fractional order PI λ controller outperforms the optimized traditional integer order proportional integral derivative (PID) controller due to the fractional order introduced as a design parameter. The simulation results show the effectiveness of the proposed controller design strategy and the robustness of fractional order controller under conditions of wind gusts and payload variations. Further real flight test results are also provided to show the advantages of the proposed PI λ controller.