Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : optimal control


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.

Optimal Model Reference Control Scheme Design for Nonlinear Strict-Feedback Systems

Musadaq A. Hadi; Hazem I. Ali

Engineering and Technology Journal, 2020, Volume 38, Issue 9, Pages 1342-1351
DOI: 10.30684/etj.v38i9A.1339

In this paper, a new design of the model reference control scheme is proposed in a class of nonlinear strict-feedback system. First, the system is analyzed using Lyapunov stability analysis. Next, a model reference is used to improve system performance. Then, the Integral Square Error (ISE) is considered as a cost function to drive the error between the reference model and the system to zero. After that, a powerful metaheuristic optimization method is used to optimize the parameters of the proposed controller. Finally, the results show that the proposed controller can effectively compensate for the strictly-feedback nonlinear system with more desirable performance.

Full State Feedback 𝐇𝟐 and H-infinity Controllers Design for a Two Wheeled Inverted Pendulum System

Hazem I. Ali; Zain. M. Shareef

Engineering and Technology Journal, 2018, Volume 36, Issue 10A, Pages 1110-1121
DOI: 10.30684/etj.36.10A.12

In this work, two robust controllers, which are full state feedback, 𝐻2 and full state feedback 𝐻∞ controllers are proposed for the two wheeled inverted pendulum system. The nonlinear equations for the two wheeled inverted pendulum system are developed using Euler – Lagrange equation. The system parameters changes are considered to show the effectiveness of the proposed robust controllers. These controllers are proposed not only to stabilize the pendulum in upright position but also to drive the position to track a given reference input. The results show that more desirable robustness and time response specifications can be achieved using the proposed controllers. The effectiveness of the proposed controllers is verified experimentally using real two wheeled inverted pendulum system.

Damping of Power System Oscillations by Using Coordinated Control of PSS and STATCOM Devices

Rashid H. Al- Rubayi; Inaam Ibrahim Ali

Engineering and Technology Journal, 2010, Volume 28, Issue 23, Pages 6814-6830

The main objective of this paper is to investigate the power system stability enhancement via coordinated control of PSS and static synchronous compensator (STATCOM) based controllers. Also, investigate the effectiveness and dynamic interaction of STATCOM controllers in damping system oscillation. Proposed optimal pole shifting technique to design damping controller of excitation system (PSS) and STATCOM based
controller. The method is based on modern control theory for multi-input and multi-output system. Several control schemes are proposed. The effectiveness of the proposed control schemes in improving the power system is verified through eigenvalues and time domain simulations under nominal loading conditions. The analysis of cases under study show that, the STATCOM – based controller has good effect on improving system damping and the coordinated control of PSS and STATCOM – based controller provide the best means for
stabilizing power system, more damping with less control effort than individual control