International Journal of Nonlinear Dynamics and Control (6 papers in press)
Genetic model reference adaptive control of shell heavy oil fractionator
by Dauda Araromi, Aminah Sulayman, Olajide Ajala
Abstract: Fractionators are characterized by high non-linear dynamic behaviour, strong loop interactions and model uncertainties. Relative Gain Array was used to determine the level of loop interaction. Dynamic decoupler was used to remove the interactions which were obtained using feed-forward design technique. A feedback control system is designed for the dynamic decoupled plant using Ziegler-Nichols tuned Proportional Integral (PI) controller. A Genetic Model Reference Adaptive Controller (GMRAC) is designed to control the fractionator using a second order reference model and adaptation mechanism based on genetic algorithm. Genetic algorithm uses real coded data generation for optimization. Comparison is made with the PI controller. Performance indices were based on settling time, rise time and overshoot.
Keywords: GMRAC; adaptive control; PI; MATLAB; relative gain array; shell heavy oil fractionator.
Dynamic Flow Control of a Photovoltaic Pumping System Based Asynchronous Induction Motor
by LAYATE Zakaria, BAHI Tahar, LEKHCHINE Salima
Abstract: In this study, a dynamic control have been developed to improve the performances of photovoltaic system fed three phases induction motor drive which serves for pumping applications. Photovoltaic systems have one of the highest potentials for generating electrical power. In this systems, the photovoltaic cell is the basic device of the conversion process. Indeed, photovoltaic cells are low power generators. Therefore, association of serial and parallel cells and modules forming photovoltaic generator is mostly recommended for supplying isolated areas where pumping systems play a predominant role. However, the generated power depends ,essentially, on climatic parameters especially the temperature and the solar irradiation. So, to improve photovoltaic installations yield, a maximum power point tracker controller embedded boost converter which serves to maximize produced power whatever climatic operating conditions. furthermore, due to the remarkable performances, the researches proved that pumping systems based photovoltaic generators have became ideal structures for remote areas.
The simulation results under MatLab/Simulink software reveal that the proposed system is versatile.
Keywords: Renewable energy; photovoltaic; motor; inverter; pumping; MPPT; control;.
Chaotic Financial System with Uncertain Parameters - Its Control and Synchronisation
by Babatunde Idowu, Olasunkanmi I. Olusola, Okpabi S. Onma, Sundarapandian Vaidyanathan, Cornelius O. Ogabi, Olujimi A. Adejo
Abstract: This paper examines the control and synchronisation of the chaotic financial system with uncertain parameters as well as known parameters using adaptive control technique. The designed adaptive controller control and globally synchronises two identical chaotic financial systems evolving from different initial conditions. The designed controller is capable of stabilizing the financial system at any position as well as controlling it to track any trajectory that is a smooth function of time. Numerical simulations are presented to demonstrate the feasibility of the proposed schemes.
Keywords: Chaotic Financial System; Adaptive control; Lyapunov exponent; uncertain parameters; economics.
Reduced Order Synchronization for Circular Restricted Three Body Problem using Adaptive Sliding Mode Controller
by Mohammad Shahzad
Abstract: This paper studies the reduced order synchronization for a circular restricted three body problem and Lorenz system as drive and response systems respectively via a robust adaptive sliding mode control in which controllers are based on negligible chattering phenomenon. The entire study has been carried out under the effect of both unknown model uncertainties and external disturbance. Also for the same drive-response system, a secure communication scheme has been presented.
Keywords: Chaos synchronization; Adaptive sliding mode control; Circular restricted three body problem.
Special Issue on: Synchronisation and Nonlinear Control Engineering Systems
ENERGY EXTRACTION BY AN OSCILLATING SYSTEM FROM A SHAKER OR WAVE FIELD
by Tatyana Krasnopolskaya, Evgeniy Pechuk
Abstract: The purpose of our work is to study an oscillating system and an electro-dynamical transducer, which are driven either by the amplifier or wave field. In the first case electrical current produced by an amplifier is converted by the transducer into mechanical force, which leads to vibrations of the base. A mechanical oscillator is mounted on the transducer base. The influence of oscillator vibrations on the formation of the driving force leads to a number of specific effects, in particular, to the Sommerfeld Kononenkos effect. Steady-state regimes of the constructed model are investigated by methods of the theory of dynamical systems. Expressions for supplied and consumed powers are shown and investigated for regular and chaotic regimes. The inverse problem model is also discussed. The classical results for wave power absorption by wave energy extractor as a single degree of freedom system are presented in the second considered problem. The example includes an axisymmetric buoy which oscillates and is subjected to its natural hydrostatic restoring force. Main attention focuses on the values and expressions for the mean powers. The expression for the maximum mean power is given for the considering system.
Keywords: Sommerfeld – Kononenko effect; steady – state regimes; energy extractor.
Special Issue on: GEEE-2018 New Contributions on Advanced Control Techniques
Quadcopter Attitude and Altitude Tracking by using improved PD Controllers
by KHADIJA EL HAMIDI, Mostafa Mjahed, Abdeljalil El Kari, Hassan Ayad
Abstract: The quadcopter is a complex coupled nonlinear system with unstable behavior, which makes it difficult to control. Therefore, in this paper, we present an effective control method based on neural network gain-scheduled PD (NNGS-PD) and model reference controller based PD (MRC-PD) for quadcopter attitude stabilization and altitude tracking. Both nonlinear and linear methods verified the stability and robustness of the proposed controllers. The simulation results illustrate that the synthesis control methods have good performance in terms of attitude and altitude tracking when faced with external disturbances.
Keywords: Quadcopter; Nonlinear; Attitude; Altitude; Proportional-Derivative; Parameter tuning; Neural network; Reference model.