scholarly journals Controlling Neimark-Sacker Bifurcation in Delayed Species Model Using Feedback Controller

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Jie Ran ◽  
Yanmin Liu ◽  
Jun He ◽  
Xiang Li

Based on the stability and orthogonal polynomial approximation theory, the ordinary, dislocated, enhancing, and random feedback control methods are used to suppress the Neimark-Sacker bifurcation to fixed point in this paper. It is shown that the convergence rate of enhancing feedback control and random feedback control can be faster than those of dislocated and ordinary feedback control. The random feedback control method, which does not require any adjustable control parameters of the model, just only slightly changes the random intensity. Finally, numerical simulations are presented to verify the effectiveness of the proposed controllers.

2019 ◽  
Vol 33 (23) ◽  
pp. 1950273 ◽  
Author(s):  
Cong Zhai ◽  
Weitiao Wu

Connected vehicles are expected to become commercially available by the next decade, while traffic interruption is not uncommon in the real traffic environment. In this paper, we propose a feedback control method for lattice hydrodynamic model considering the traffic interruption probability effect. The stability criterion of the new model is explored through linear stability analysis of transfer function. When the stability conditions are not satisfied, a delay feedback controller is used to control the discharging flow to suppress traffic congestion. The impact of gain coefficient and delay time on the performance is discussed. We verify the effectiveness of the devised delay feedback controller by simulations. Results show that the traffic interruption probability effect has a considerable impact on the stability of traffic flow, while the controller is effective in suppressing traffic congestion.


2020 ◽  
Vol 42 (14) ◽  
pp. 2822-2829
Author(s):  
Kexin Xu ◽  
Xianqing Wu ◽  
Miao Ma ◽  
Yibo Zhang

In this paper, we consider the control issues of the two-dimensional translational oscillator with rotational actuator (2DTORA) system, which has two translational carts and one rotational rotor. An output feedback controller for the 2DTORA system is proposed, which can prevent the unwinding behaviour. In addition, the velocity signal unavailability and actuator saturation are taken into account, simultaneously. In particular, the dynamics of the 2DTORA system are given first. On the basis of the passivity and control objectives of the 2DTORA system, an elaborate Lyapunov function is constructed. Then, based on the introduced Lyapunov function, a novel output feedback control method is proposed straightforwardly for the 2DTORA system. Lyapunov theory and LaSalle’s invariance principle are utilized to analyse the stability of the closed-loop system and the convergence of the states. Finally, simulation results are provided to illustrate the excellent control performance of the proposed controller in comparison with the existing method.


2014 ◽  
Vol 1008-1009 ◽  
pp. 556-561
Author(s):  
Xing Yang ◽  
Xiang Shun Li

Aiming at the problem that sail-assisted ship is easy to yaw because of sail’s lateral force and adjusts its course slowly due to wind, wave and other interferences on the sea, this paper put forward a feedforward feedback control method based on fuzzy system. According to the relationship between lateral force and yaw angle, a feedforward controller was designed to offset the yaw of ship. In order to correct the drift angle of ship automatically, the feedback controller was fulfilled to track the given course. Feedback control loop adopted fuzzy self-adjusting PD controller to make the drift angle be adjusted in time. The simulations indicate that the feedforward feedback control can suppress the disturbance produced by lateral force effectively, enhance the stability of the system and accelerate the response speed.


Author(s):  
Aiwen Meng ◽  
Hak-Keung Lam ◽  
Fucai Liu ◽  
Ziguang Wang

This paper presents the stabilization for positive nonlinear systems using polynomial fuzzy models. To conform better to the practical scenarios that system states are not completely measurable, the static output feedback (SOF) control strategy instead of the state feedback control method is employed to realize the stability and positivity of the positive polynomial fuzzy system (PPFS) with satisfying L1-induced performance. However, some troublesome problems in analysis and control design will follow, such as the non-convex problem. Fortunately, by doing mathematical tricks, the non-convex problem is skillfully dealt with. Furthermore, the neglect of external disturbances may lead to a great negative impact on the performance of positive systems. For the sake of guaranteeing the asymptotic stability and positivity under the satisfaction of the optimal performance of the PPFS, it is significant to take the L1-induced performance requirement into consideration as well. In addition, a linear co-positive Lyapunov function is chosen so that the positivity can be extracted well and the stability analysis becomes simple. By using the sum of squares (SOS) technique, the convex stability and positivity conditions in the form of SOS are derived. Eventually, for illustrating the advantages of the proposed method, a simulation example is shown in the simulation section.


2009 ◽  
Vol 21 (4) ◽  
pp. 541-553 ◽  
Author(s):  
Hiroaki Yamaguchi ◽  

This paper introduces and describes a new type of undulatory wheeled locomotor, which we refer to as a “trident steering walker.” The wheeled locomotor is a nonholonomic mechanical system, which consists of an equilateral triangular base, three joints, three links and four steering systems. The equilateral triangular base has a steering system at its center of mass. At each apex of the base is a joint which connects the base and a link. The link has a steering system at its midpoint. The wheeled locomotor transforms driving the three joints into its movement by operating the four steering systems. This means that the wheeled locomotor achieves undulatory locomotion in which changes in its own shape are transformed into its net displacement. We assume that there is a virtual joint at the end of the first link. The virtual joint connects the first link and a virtual link which has a virtual axle at its midpoint and a virtual steering system at its end. We prove that, by assuming the presence of such virtual mechanical elements, it is possible to convert the kinematical equation of the trident steering walker into five-chain, single-generator chained form in a mathematical framework, differential geometry. Based on chained form, we derive a path following feedback control method which causes the trident steering walker to follow a straight path. We also define a performance index of propulsion of the trident steering walker to design its control parameters. The validity of the mechanical design of the trident steering walker, the conversion of its kinematical equation into chained form, the straight path following feedback control method, and the design of the control parameters reflecting the performance index of propulsion has been verified by computer simulations.


2019 ◽  
Vol 33 (27) ◽  
pp. 1950327
Author(s):  
Juju Hu ◽  
Qin Xue ◽  
Yinghua Ji

For stochastic quantum systems with given dissipations, the identification method of Hamiltonian is given in this paper. First, the stability of the system is realized through designing a real-time feedback control method. Second, by using Routh–Hurwitz stability criterion, the intervals of the element values of the system Hamiltonians are given. Finally, the identification of Hamiltonian is realized by selecting the equilibrium state of the system equal to the desired target state. For two typical categories of noise: Purely dephasing decoherence and amplitude damping decoherence, we check the validity of the proposed estimation scheme.


Author(s):  
Gao Ming-Zhou ◽  
Chen Xin-Yi ◽  
Han Rong ◽  
Yao Jian-Yong

To suppress airfoil flutter, a lot of control methods have been proposed, such as classical control methods and optimal control methods. However, these methods did not consider the influence of actuator faults and control delay. This paper proposes a new finite-time H∞ adaptive fault-tolerant flutter controller by radial basis function neural network technology and adaptive fault-tolerant control method, taking into account actuator faults, control delay, modeling uncertainties, and external disturbances. The theoretic section of this paper is about airfoil flutter dynamic modeling and adaptive fault-tolerant controller design. Lyapunov function and linear matrix inequality are employed to prove the stability of the proposed control method of this paper. The numeral simulation section further proves the effectiveness and robustness of the proposed control algorithm of this paper.


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