A high-gain-based global finite-time nonlinear observer

In this paper, a global finite-time observer is designed for a class of nonlinear systems with bounded rational powers imposed on the incremental nonlinearities. Compared with the previous global finite-time results, the new observer designed here is with a new gain update law. Moreover, an example is given to show that the proposed observer can reduce the time of the observation error convergence.National Science Foundation of China (Nos. 61074091, 61174216 and 51177088), the National Science Foundation of Hubei Province (2010CDB10807, 2011CDB187) and the Scientific Innovation Team Project of Hubei Provincial Department of Education (T200809, T201103).http://www.tandfonline.com/loi/tcon20hb201

Continuous observer design for a class of multi-output nonlinear systems with multi-rate sampled and delayed output measurements

In this paper, continuous observer is designed for a class of multi-output nonlinear systems with multirate sampled and delayed output measurements. The time delay may be larger or less than the sampling intervals. The sampled and delayed measurements are used to update the observer whenever they are available. Sufficient conditions are presented to ensure global exponential stability of the observation errors by constructing a Lyapunov–Krasovskii function. A numerical example is given to illustrate the effectiveness of the proposed methods.http://www.elsevier.com/locate/automatica2018-01-31hb2017Electrical, Electronic and Computer Engineerin

Globally uniformly ultimately bounded observer design for a class of nonlinear systems with sampled and delayed measurements

In this paper, we consider two kinds of sampled-data observer design for a class of nonlin- ear systems. The system output is sampled and transmitted under two kinds of truncations. Firstly, we present de nitions of the truncations and the globally uniformly ultimately bounded observer, respectively. Then, two kinds of observers are proposed by using the delayed measure- ments with these two truncations, respectively. The observers are hybrid in essence. For the rst kind of observers, by constructing a Lyapunov{Krasovskii functional, su cient conditions of globally uniformly ultimately bounded of the estimation errors are derived, and the maxi- mum allowable sampling period and the maximum delay are also given. For the second ones, su cient conditions are also given to ensure that the estimation errors are globally uniformly ultimately bounded. Finally, an example is provided to illustrate the design methods.The National Science Foundation of China (61374028), Grant National Science Foundation of Hubei Provincial (2013CFA050), and the Scientific Innovation Team Project of Hubei Provincial Department of Education (T201504).http://dml.cz/dmlcz/145785am2017Electrical, Electronic and Computer Engineerin

Simultaneous identification, tracking control and disturbance rejection of uncertain nonlinear dynamics systems: A unified neural approach

Previous works of traditional zeroing neural networks (or termed Zhang neural networks, ZNN) show great success for solving specific time-variant problems of known systems in an ideal environment. However, it is still a challenging issue for the ZNN to effectively solve time-variant problems for uncertain systems without the prior knowledge. Simultaneously, the involvement of external disturbances in the neural network model makes it even hard for time-variant problem solving due to the intensively computational burden and low accuracy. In this paper, a unified neural approach of simultaneous identification, tracking control and disturbance rejection in the framework of the ZNN is proposed to address the time-variant tracking control of uncertain nonlinear dynamics systems (UNDS). The neural network model derived by the proposed approach captures hidden relations between inputs and outputs of the UNDS. The proposed model shows outstanding tracking performance even under the influences of uncertainties and disturbances. Then, the continuous-time model is discretized via Euler forward formula (EFF). The corresponding discrete algorithm and block diagram are also presented for the convenience of implementation. Theoretical analyses on the convergence property and discretization accuracy are presented to verify the performance of the neural network model. Finally, numerical studies, robot applications, performance comparisons and tests demonstrate the effectiveness and advantages of the proposed neural network model for the time-variant tracking control of UNDS

Design and Implementation of Secure Chaotic Communication Systems

Chaotic systems have properties such as ergodicity, sensitivity to initial conditions/parameter mismatches, mixing property, deterministic dynamics, structure complexity, to mention a few, that map nicely with cryptographic requirements such as confusion, diffusion, deterministic pseudorandomness, algorithm complexity. Furthermore, the possibility of chaotic synchronization, where the master system (transmitter) is driving the slave system (receiver) by its output signal, made it probable for the possible utilization of chaotic systems to implement security in the communication systems. Many methods like chaotic masking, chaotic modulation, inclusion, chaotic shift keying (CSK) had been proposed however, many attack methods later showed them to be insecure. Different modifications of these methods also exist in the literature to improve the security, but almost all suffer from the same drawback. Therefore, the implementation of chaotic systems in security still remains a challenge. In this work, different possibilities on how it might be possible to improve the security of the existing methods are explored. The main problem with the existing methods is that the message imprint could be found in the dynamics of the transmitted signal, therefore by some signal processing or pattern classification techniques, etc, allow the exposition of the hidden message. Therefore, the challenge is to remove any pattern or change in dynamics that the message might bring in the transmitted signal

Finite-time synchronization of multi-layer nonlinear coupled complex networks via intermittent feedback control

This paper addresses the problem of finite-time synchronization for a class of multi-layer nonlinear coupled complex networks via intermittent feedback control. Firstly, based on finite-time stability theory, some novel criteria are given to guarantee that the error system of drive-response systems is still finite-time stable under an inherently discontinuous controller. Then, by proposing two kinds of intermittent feedback control laws, sufficient conditions of finite-time synchronization of two kinds of multi-layer complex networks are derived, respectively. The time delay between different layers is also taken into consideration. Finally, a numerical example is provided to verify the effectiveness of the proposed methods.http://www.elsevier.com/locate/neucom2018-02-28hb2017Electrical, Electronic and Computer Engineerin

Finite-time synchronization of drive-response systems via periodically intermittent adaptive control

In this paper, the finite-time synchronization between two complex dynamical networks via the periodically intermittent adaptive control and periodically intermittent feedback control is studied. The finite-time synchronization criteria are derived based on finite-time stability theory, the differential inequality and the analysis technique. Since the traditional synchronization criteria for some models are improved in the convergence time by using the novel periodically intermittent adaptive control and periodically intermittent feedback control , the results of this paper are important. Numerical examples are finally presented to illustrate the effectiveness and correctness of the theoretical results.National Natural Science Foundation of China (Grant No.61174216, No. 61273183, No.6134028 and No. 61374085) and the Doctoral Scientific Foundation of China Three Gorges University (Grant No. 0620120132).http://www.elsevier.com/locate/jfranklinhb201