Open Science Research Excellence

Mohammad Haeri

Publications

6

Publications

6
9757
Chaos Synchronization Using Sliding Mode Technique
Abstract:
In this paper, an effective sliding mode design is applied to chaos synchronization. The proposed controller can make the states of two identical modified Chua-s circuits globally asymptotically synchronized. Numerical results are provided to show the effectiveness and robustness of the proposed method.
Keywords:
Sliding mode, Chaos synchronization, Modified Chua's circuit.
5
9902
Design of an Stable GPC for Nonminimum Phase LTI Systems
Abstract:
The current methods of predictive controllers are utilized for those processes in which the rate of output variations is not high. For such processes, therefore, stability can be achieved by implementing the constrained predictive controller or applying infinite prediction horizon. When the rate of the output growth is high (e.g. for unstable nonminimum phase process) the stabilization seems to be problematic. In order to avoid this, it is suggested to change the method in the way that: first, the prediction error growth should be decreased at the early stage of the prediction horizon, and second, the rate of the error variation should be penalized. The growth of the error is decreased through adjusting its weighting coefficients in the cost function. Reduction in the error variation is possible by adding the first order derivate of the error into the cost function. By studying different examples it is shown that using these two remedies together, the closed-loop stability of unstable nonminimum phase process can be achieved.
Keywords:
GPC, Stability, Varying Weighting Coefficients.
4
10099
Anti-Synchronization of two Different Chaotic Systems via Active Control
Abstract:
This paper presents anti-synchronization of chaos between two different chaotic systems using active control method. The proposed technique is applied to achieve chaos antisynchronization for the Lü and Rössler dynamical systems. Numerical simulations are implemented to verify the results.
Keywords:
Active control, Anti-Synchronization, Chaos, Lü system, Rössler system.
3
10928
A New Stabilizing GPC for Nonminimum Phase LTI Systems Using Time Varying Weighting
Abstract:
In this paper, we show that the stability can not be achieved with current stabilizing MPC methods for some unstable processes. Hence we present a new method for stabilizing these processes. The main idea is to use a new time varying weighted cost function for traditional GPC. This stabilizes the closed loop system without adding soft or hard constraint in optimization problem. By studying different examples it is shown that using the proposed method, the closed-loop stability of unstable nonminimum phase process is achieved.
Keywords:
GPC, Stability, Varying Weighting Coefficients.
2
13696
An Adaptive Approach to Synchronization of Two Chua's Circuits
Abstract:

This paper introduces an adaptive control scheme to synchronize two identical Chua's systems. Introductory part of the paper is presented in the first part of the paper and then in the second part, a new theorem is proposed based on which an adaptive control scheme is developed to synchronize two identical modified Chua's circuit. Finally, numerical simulations are included to verify the effectiveness of the proposed control method.

Keywords:
Chaos synchronization, adaptive control, Chua's circuits.
1
15680
Comparison of the Existing Methods in Determination of the Characteristic Polynomial
Abstract:
This paper presents comparison among methods of determination of the characteristic polynomial coefficients. First, the resultant systems from the methods are compared based on frequency criteria such as the closed loop bandwidth, gain and phase margins. Then the step responses of the resultant systems are compared on the basis of the transient behavior criteria including overshoot, rise time, settling time and error (via IAE, ITAE, ISE and ITSE integral indices). Also relative stability of the systems is compared together. Finally the best choices in regards to the above diverse criteria are presented.
Keywords:
Characteristic Polynomial, Transient Response, Filters, Stability.