scholarly journals Limit Cycle Prediction Based on Evolutionary Multiobjective Formulation

2009 ◽  
Vol 2009 ◽  
pp. 1-17 ◽  
Author(s):  
M. Katebi ◽  
H. Tawfik ◽  
S. D. Katebi

This paper is concerned with an evolutionary search for limit cycle operation in a class of nonlinear systems. In the first part, single input single output (SISO) systems are investigated and sinusoidal input describing function (SIDF) is extended to those cases where the key assumption in its derivation is violated. Describing function matrix (DMF) is employed to take into account the effects of higher harmonic signals and enhance the accuracy of predicting limit cycle operation. In the second part, SIDF is extended to the class of nonlinear multiinput multioutput (MIMO) systems containing separable nonlinear elements of any general form. In both cases linearized harmonic balance equations are derived and the search for a limit cycle is formulated as a multiobjective problem. Multiobjective genetic algorithm (MOGA) is utilized to search the space of parameters of theoretically possible limit cycle operations. Case studies are presented to demonstrate the effectiveness of the proposed approach.

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Assil Ayadi ◽  
Soufien Hajji ◽  
Mohamed Smaoui ◽  
Abdessattar Chaari

This paper aims to propose and develop an adaptive moving sliding mode controller (AMSMC) that can be applied for nonlinear single-input single-output (SISO) systems with external disturbances. The main contribution of this framework consists to overcome the chattering phenomenon problem. The discontinuous term of the classic sliding mode control is replaced by an adaptive term. Moreover, a moving sliding surface is proposed to have better tracking and to guarantee robustness to the external disturbances. The parameters of the sliding surface and the adaptive law are deduced based on Lyapunov stability analysis. An experimental application of electropneumatic system is treated to validate the theoretical results.


2004 ◽  
Vol 126 (3) ◽  
pp. 558-567 ◽  
Author(s):  
Matt Bement ◽  
Suhada Jayasuriya

The problem of tracking a known reference without overshooting is of great practical importance in a number of applications. However, nonminimum phase systems and systems with reference inputs other than steps have received very little attention. This paper proposes two different techniques for obtaining a continuous time, nonovershooting, feedback controller for a wide variety of linear single input, single output (SISO) systems, including nonminimum phase systems and systems whose reference input is something other than a step function. These techniques are then used to generate an initial nonovershooting controller from which a set of nonovershooting controllers is obtained. Examples are given to demonstrate all key concepts.


1999 ◽  
Vol 121 (3) ◽  
pp. 479-486 ◽  
Author(s):  
A. S. Cherry ◽  
R. P. Jones ◽  
T. E. C. Potter

This paper describes the use of realistic analytical techniques to address automotive ride control. Multibody system (MBS) modeling techniques were used to develop a full vehicle model with suspension system representation, which was subsequently validated against experimental data. The resultant multivariable ride control problem was then decoupled in the frequency domain by the application of equivalence transformation techniques. It is shown that diagonalization can be achieved for the range of primary ride frequencies, and that the decoupled system then consists of three single-input/single-output (SISO) systems, one for each of the sprung mass modes. Finally, feedback control design for each sprung mass mode loop is illustrated by the application of modal damping.


Author(s):  
Farouk Shakir ◽  
Mazin Ali A. Ali ◽  
Firas Ameer

Free-space optical (FSO) communication consider license free, high data rate, wide bandwidth and cost-effective. Multi-input Multi-output (MIMO) systems can be employed to reduce the attenuation by heavy fog and improve FSO channel capacity. In this paper a single-input single-output and multi–input multi-output examined to investigate the performance of these systems under heavy fog. A comparison is made in terms of received optical power, signal to noise ratio, and bit error rate (BER) using OptiSystem version 7.0. The signal reaches to link up to 1.7km, 1.55km, 1.5km, and 1.4km for 4Tx/4Rx, 3Tx/3Rx, 2Tx/2Rx, 1Tx/1Rxrespectively. The results showed that the quality of received power is enhancement by using up to four beams.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Guofeng Wang ◽  
Kai Zheng ◽  
Xingcheng Wang ◽  
Shuanghe Yu

The problem of designing a sliding mode controller with uncertain sliding surface for a class of uncertain single-input-single-output systems is studied. The design case is handled by using the invariant transformation first in order to separate the sliding mode and the reaching mode of the sliding mode control system. It is shown that the sliding mode design needs not to consider the uncertainties of the sliding surface, which can be handled in the reaching phase design. The results generalize the robust design of the reaching phase such that one specific reaching phase design may agree with several sliding surfaces.


1988 ◽  
Vol 110 (2) ◽  
pp. 134-142 ◽  
Author(s):  
A. Nassirharand ◽  
J. H. Taylor ◽  
K. N. Reid

A new systematic and algebraic linear control system design procedure for use with highly nonlinear plants is developed. This procedure is based on simultaneous stabilization theory and sinusoidal-input describing function models of the nonlinear plant, and is presently applicable to single-input single-output, time-invariant, deterministic, stable, and continuous-time systems which are representable in standard state-variable differential equation form. Three software utilities to implement the controller design procedure are also outlined. This method and the associated software is applied to a position control problem of the sort encountered in robotics, and the results are compared with those previously obtained using both linear and nonlinear PID control.


Author(s):  
Rafael F Pinheiro ◽  
Diego Colón

The goal of this paper is to present a different approach to the analysis of the absolute stability of Lurie type systems in the single-input-single-output (SISO) case using robust control theory. The proposed technique enables the design of controllers via [Formula: see text] mixed-sensitivity (S/KS/T), where, besides making the system absolutely stable, the performance problem can also be solved. In addition, it is also demonstrated that it is possible to make use of this new approach in time-delay Lurie type systems. Thus, through a new methodology, this work paves the way to the study of the absolute stability of multiple-inputs-multiple-outputs (MIMO) systems, aiming at a better generalization of the theory and enabling applications in other areas, such as neural networks. Examples, numerical simulations and application in Chua’s circuit are given to illustrate the results.


2021 ◽  
Author(s):  
Leandro Ximenes ◽  
Rangel Arthur ◽  
igor Santos Cruz Rodrigues

<div>This paper proposes a novel coding scheme for Visible Light Communications (VLC) systems using symbol mapping permutations on the color domain. The permutation is done through symbol-hopping over the points of an optimized 4-CSK constellation. This scheme provides diversity gains, promises robustness against monochromatic channel degradation, and increases the information security of the communication link. It can also be used in conjunction with Single-Input and Single-Output (SISO) systems, as well as in Multiple-Input and Multiple-Output (MIMO) systems. Monte Carlo computational simulations evaluate the performance of the proposed scheme over the conventional QuadLED (QLED) CSK system and other codes, showing superior coding and diversity gains over two direct competitors, under a Rician flat-fading channel.</div>


2020 ◽  
Author(s):  
Renato A. L. de Andrade ◽  
Péricles R. Barros

Multi-input multi-output (MIMO) systems have been a major concern for decades. However, due to the intrinsic complexity raised by the process interactions and optimization issues, MIMO approaches have not been developed as extensively as the single-input single-output ones. Recently, nevertheless, several algorithms have been proposed to address this problem, most of them based on recursive algorithms and many dependent on the assumption that the transfer function denominator polynomials are the same for all subsystems. In this article, an iterative least-squares-based algorithm, a pseudolinear regression and a Gauss-Newton optimization-based algorithm are proposed to provide a continuous-time output-error multi-input single-output model by means of iterative strategies. The numerical simulations indicate the iterative least-squares-based and the pseudo-linear regression algorithms have similar performances and generate more accurate and precise estimates than the Gauss-Newton one, which presented averages and standard deviations of the parameters ranging from twice as large to one order of magnitude higher than those of the other two algorithms.


Author(s):  
D. K. Sambariya ◽  
Omveer Sharma

In this paper the Routh Approximation method is explored for getting the reduced order model of a higher order model. The reduced order modeling of a large system is necessary to ease the analysis of the system. The approach is examined and compared to single-input single-output (SISO) and multi-input multi-output (MIMO) systems. The response comparison is considered in terms of step response parameters and graphical comparisons. It is reported that the reduced order model using proposed Routh Approximation (RA) method is almost similar in behavior to that of with original systems.


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