Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Robust control


Design of Robust FOPI-FOPD Controller for Maglev System Using Particle Swarm Optimization

Salwan Y. Yousif; Mohamed J. Mohamed

Engineering and Technology Journal, 2021, Volume 39, Issue 4A, Pages 653-667
DOI: 10.30684/etj.v39i4A.1956

Magnetic Levitation System (MLS) is one of the benchmark laboratories models for designing and testing feedback control systems in the presence of the parametric uncertainties and disturbances effect. Therefore, the MLS can be regarded as a tool to study and verify a certain robust controller design. In this paper, two types of powerful control schemes are presented to control the MLS. The first controller is a robust PI-PD controller, while the other is a robust fractional order FOPI-FOPD controller which provides two extra degrees of freedom to the system. In both controller design procedures, the Particle Swarm Optimization (PSO) algorithm is used to find the best values of controller parameters subject to the time-domain objective function and H∞ constraints. All modeling processes including parameterization, optimization, and validation of the controllers are performed using MATLAB. The simulation results show that the MLS with robust FOPI-FOPD is faster and more stable than the MLS with robust classical PI-PD. Also, the proposed FOPI-FOPD controller gives far superior results than the PI-PD controller for disturbance rejection.

Optimal H-infinity PID Model Reference Controller Design for Roll Control of a Tail-Sitter VTOL UAV

Ali H. Mhmood; Hazem I. Ali

Engineering and Technology Journal, 2021, Volume 39, Issue 4A, Pages 552-564
DOI: 10.30684/etj.v39i4A.1861

In this work, an optimal and robust controller based on consolidating the PID controller and H-infinity approach with the model reference control is proposed. The proposed controller is intended to accomplish a satisfactory transient response by including the reference model. A Tail-Sitter VTOL UAV system is used to show the effectiveness of the proposed controller. A dynamic model of the system is formulated using Euler method. To optimize the design procedure, the Black Hole Optimization (BHO) method is used as a new Calibration method. The deviation between the reference model output and system output will be minimized to obtain the required specifications. The results indicate that the proposed controller is very powerful in compensating the system parameters variations and in forcing the system output to asymptotically track the output of the reference model.

H∞ loop Shaping Robust Postprandial Glucose Control for Type 1 Diabetes

Safa F. Fadhel; Safanah M. Raafat

Engineering and Technology Journal, 2021, Volume 39, Issue 2A, Pages 268-279
DOI: 10.30684/etj.v39i2A.1672

The Bergman model is one of the most commonly used models applied to the representation of the artificial pancreas (AP). It is important to study the effects of the insulin infusion on blood glucose concentration. This work includes a case study for the design of a robust controller for an AP. Robustness is a structured control that improves a system's ability to keep its stability and performance under various conditions. The proposed H∞ loop shaping HLS method will fulfill the design requirements of robust control and performance. The results of the simulation prove the superiority of the intended approach in terms of simple structure, robust performance, and stability with the least control effort

Optimal Quantitative Controller Design for Twin Rotor MIMO System

Mustafa K. Khreabet; Hazem I. Ali

Engineering and Technology Journal, 2020, Volume 38, Issue 12, Pages 1880-1894
DOI: 10.30684/etj.v38i12A.1618

In this paper, the control approach is used for achieving the desired performance and stability of the twin-rotor MIMO system. This system is considered one of the complex multiple inputs of multiple-output systems. The complexity because of the high nonlinearity, significant cross-coupling and parameter uncertainty makes the control of such systems is a very challenging task. The dynamic of the Twin Rotor MIMO System (TRMS) is the same as that in helicopters in many aspects. The Quantitative Feedback Theory (QFT) controller is added to the control to enhance the control algorithm and to satisfy a more desirable performance. QFT is one of the frequency domain techniques that is used to achieve a desirable robust control in presence of system parameters variation. Therefore, a combination between control and QFT is presented in this paper to give a new efficient control algorithm. On the other hand, to obtain the optimal values of the controller parameters, Particle Swarm Optimization (PSO) which is one of the powerful optimization methods is used. The results show that the proposed quantitative control can achieve more desirable performance in comparison to control especially in attenuating the cross-coupling and eliminating the steady-state error.

Robust Controller Analysis and Design of Medical Haptic Control System

S.M. Raafat; H.A. Ali

Engineering and Technology Journal, 2017, Volume 35, Issue 4, Pages 318-326

Haptic interfaces for medial simulation prove to be especially useful for training in minimally invasive procedures. In this research, a framework that consists of relevant representation of operator and environment dynamic of a tele-manipulated haptic system is implemented. The uncertainty model of the operator and environment models is considered as well to study the influence on the aspects of stability and performance. The framework of H∞ loop shaping robust controller design is applied, then the stability and performance analysis is investigated. Parametric robust control design method is used as well for comparison. The v-gap metric is considered to develop an accurate measurement of uncertainty. Based on the obtained value of the v-gap an efficient procedure of robust control design is applied. The obtained values of v- gap were 0.1112 for the master and 9.755*10-4 for the slave parts of the haptic system, which indicate improved robustness of stability and performance as compared with the obtained values from parametric robust controller design.

Design of a Nonlinear Robust Controller for Vibration Control of a Vehicle Suspension System

YasirKhudhair Abbas; Muhsin N.Hamza; Shibly Ahmed Al-Samarraie

Engineering and Technology Journal, 2011, Volume 29, Issue 11, Pages 2259-2273

The suspension system is the main tool to achieve ride comfort and drive safety for a vehicle. Passive suspension systems have been designed to obtain a good compromise between these objectives, but intrinsic limitations prevent them from obtaining the best performances for both goals. In present work, a robust controller for the active suspension system has been designed to get the best performance of the
suspension system. The nonlinear robust controller is designed based on adding an integrator to a two-degree-of-freedom quarter-car model. The control action will decouple the upper sprung mass subsystem from the lower (unsprung mass) subsystem after a certain small period of time. As a result, by adjusting the control law parameters, the dynamical response for the sprung mass subsystem is freely specified (the damping ratio and the natural frequency for the sprung system after
decoupling). The simulation results, which are carried out by using Matlab/Simulink, proved the effectiveness of the proposed control law. The results confirmed that the sprung mass system is decoupled from the lower unsprung system and unaffected by the change in sprung mass and the road excitation disturbance. Additionally, the time history of the
sprung mass response is according to a mass spring system response with the desired damping ratio and the natural frequency.