Fractional Order Universal Adaptive Stabilizer for Fractional Order Systems

Author(s):  
Yan Li ◽  
YangQuan Chen

In this paper, the fractional order universal adaptive stabilization of fractional order SISO system is discussed. The fractional universal adaptive stabilizer is u(t) = −k(t)sgn{CB}y(t), where 0Dtβk(t) = ‖y(t)‖p, which guarantees the asymptotic stability of the equilibrium point of fractional order state space system with finite control effort. Moreover, the fractional order system with order α ∈ (0, 1/(1+p)) can be stabilized by the fractional controller but not for the integer order controller. Simulation results are provided as the proof of concepts.

2012 ◽  
Vol 22 (04) ◽  
pp. 1250081 ◽  
Author(s):  
YAN LI ◽  
YANGQUAN CHEN

In this paper, a fractional order universal high gain adaptive stabilizer is proposed which guarantees the Lp stability of fractional order multiple–input and multiple–output (MIMO) systems with finite control effort. The boundedness of the control gain for the fractional order universal adaptive strategy is discussed for fractional order MIMO systems, and an upper bound of the control gain is presented for fractional order single-input and single-output (SISO) systems. Some advantages of the discussed fractional order universal adaptive stabilizer are demonstrated in numerical simulations, such as the overshoots of system outputs can be efficiently reduced by decreasing the fractional order of the universal adaptive stabilizer without significantly increasing the system gains.


Author(s):  
P R Houlston

This technical note concerns the reformation of a second-order system from an arbitrary first-order system. At present, the majority of control literature is concerned with controlling systems within the first-order linearization of a system. The author is part of a growing community looking to expand the direct control of second-order systems and the benefits associated in doing so. However, there are potential stages of system modelling that may result in it being necessary to form the first-order form of the system, such as model reduction. This may have the effect of destroying the second-order notion of the system. The purpose of this note is to regain the structure of the second-order system and thus enable the benefits of direct second-order control to be realized. Although the problem itself has been previously resolved, the author proposes the virtue of a simpler method.


Symmetry ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 55
Author(s):  
Xiaomin Tian ◽  
Zhong Yang

In this paper, a new backstepping-based adaptive stabilization of a fractional-order system with unknown parameters is investigated. We assume that the controlled system is perturbed by external disturbance, the bound of external disturbance to be unknown in advance. Moreover, the effects of sector and dead-zone nonlinear inputs both are taken into account. A fractional-order auxiliary system is established to generate the necessary signals for compensation the nonlinear inputs. Meantime, in order to deal with these unknown parameters, some fractional-order adaption laws are given. The frequency-distributed model is used so that the indirect Lyapunov theory is available in designing controllers. Finally, simulation results are presented to verify the effectiveness and robustness of the proposed control strategy.


2016 ◽  
Vol 17 (1) ◽  
pp. 115-126
Author(s):  
Morteza Pourmehdi ◽  
Abolfazl Ranjbar Noei ◽  
Jalil Sadati

In this manuscript, for the first time, a fractional-order manifold in a synergetic approach using a fractional order controller is introduced. Furtheremore, in the synergetic theory a macro variable is expended into a linear combination of state variables. An aim is to increase the convergence rate as well as time response of the whole closed loop system. Quality of the proposed controller is investigated to control and synchronize a nonlinear chaotic Coullet system in comparison with an integer order manifold synergetic controller. The stability of the proposed controller is proven using the Lyapunov method. In this regard stabilizing control effort is yielded. Simulation result confirm convergence of states towards zero. This is achieved through a control effort with fewer oscillations and lower amplitude of signls which confirm feasibility of the control effort in practice.KEYWORDS:  synergetic control theory; fractional order system; synchronization; nonlinear chaotic Coullet system; chaos control


2008 ◽  
Vol 42 (6-8) ◽  
pp. 939-951 ◽  
Author(s):  
Tounsia Jamah ◽  
Rachid Mansouri ◽  
Saïd Djennoune ◽  
Maâmar Bettayeb

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