A Fractional Order Control and Correction Strategy for EtherCAT Communication Clock Drift

2021 ◽  
Author(s):  
Jihao Sun ◽  
Pengchong Chen ◽  
Ying Luo
Keyword(s):  
Fractional Order ◽  
Clock Synchronization ◽  
Synchronization Error ◽  
Crystal Oscillator ◽  
Loop Control ◽  
Clock Drift ◽  
Proportional Integral ◽  
Synchronization Problem ◽  
Control Automation ◽  
Reference Clock

Abstract Ethernet Control Automation Technology (EtherCAT) applies distributed clock (DC) to realize synchronization among different slaves. Due to the influence of the crystal oscillator manufacturing process and environment, there is still synchronization error between reference clock and non-reference clock. To solve the clock synchronization problem, this paper proposes a clock drift compensation algorithm based on the idea of closed-loop control. By designing integer-order proportional integral (IOPI) and fractional-order proportional integral (FOPI) controllers, the synchronization error between slaves can be minimized. The IOPI and FOPI controllers designed in this paper are used to eliminate the drift error. This method improves the synchronization accuracy without bringing too much computational load. The results show that the proposed FOPI controller can effectively reduce the synchronization error with even better performance over the IOPI controller.

Sliding mode projective synchronization for fractional-order coupled systems based on network without strong connectedness

2021 ◽  
pp. 014233122110009
Author(s):  
Xin Meng ◽  
Baoping Jiang ◽  
Cunchen Gao
Keyword(s):  
Fractional Order ◽  
Sliding Mode ◽  
Coupled Systems ◽  
Projective Synchronization ◽  
Slave System ◽  
Complete Synchronization ◽  
Synchronization Problem ◽  
Strong Connectedness ◽  
Master System ◽  
Error System

This paper considers the Mittag-Leffler projective synchronization problem of fractional-order coupled systems (FOCS) on the complex networks without strong connectedness by fractional sliding mode control (SMC). Combining the hierarchical algorithm with the graph theory, a new SMC strategy is designed to realize the projective synchronization between the master system and the slave system, which covers the globally complete synchronization and the globally anti-synchronization. In addition, some novel criteria are derived to guarantee the Mittag-Leffler stability of the projective synchronization error system. Finally, a numerical example is given to illustrate the validity of the proposed method.

Complex projection synchronization of fractional order uncertain complex-valued networks with time-varying coupling

2019 ◽  
Vol 33 (29) ◽  
pp. 1950351 ◽  
Author(s):  
Dawei Ding ◽  
Xiaolei Yao ◽  
Hongwei Zhang
Keyword(s):  
Fractional Order ◽  
Coupling Strength ◽  
Dynamic Networks ◽  
Sufficient Conditions ◽  
Feedback Gain ◽  
Time Varying ◽  
Order Complex ◽  
Unknown Parameters ◽  
Synchronization Problem ◽  
Complex Valued

In this paper, the complex projection synchronization problem of fractional complex-valued dynamic networks is investigated. Considering the time-varying coupling and unknown parameters of the fractional order complex network, several decentralized adaptive strategies are designed to adjust the coupling strength and controller feedback gain in order to investigate the complex projection synchronization problem of the system. Moreover, based on the designed identification law, the uncertain parameters in the network can be estimated. Using adaptive law which balances the time-varying coupling strength and the feedback gain of the controller, some sufficient conditions are obtained for the complex projection synchronization of complex networks. Finally, numerical simulation examples are provided to illustrate the efficiency of the complex projection synchronization strategies of the fractional order complex dynamic networks.

HYPERCHAOS IN THE FRACTIONAL-ORDER NONAUTONOMOUS CHEN'S SYSTEM AND ITS SYNCHRONIZATION

2005 ◽  
Vol 16 (05) ◽  
pp. 815-826 ◽  
Author(s):  
HONGBIN ZHANG ◽  
CHUNGUANG LI ◽  
GUANRONG CHEN ◽  
XING GAO
Keyword(s):  
Numerical Simulations ◽  
Fractional Order ◽  
Chaotic System ◽  
Three Dimensional ◽  
Synchronization Problem ◽  
Driving Signal

Recently, a new hyperchaos generator, obtained by controlling a three-dimensional autonomous chaotic system — Chen's system — with a periodic driving signal, has been found. In this letter, we formulate and study the hyperchaotic behaviors in the corresponding fractional-order hyperchaotic Chen's system. Through numerical simulations, we found that hyperchaos exists in the fractional-order hyperchaotic Chen's system with order less than 4. The lowest order we found to have hyperchaos in this system is 3.4. Finally, we study the synchronization problem of two fractional-order hyperchaotic Chen's systems.

A novel fractional order PID plus derivative (PIλDµDµ2) controller for AVR system using equilibrium optimizer

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Abdulsamed Tabak
Keyword(s):  
Fractional Order ◽  
Transient Response ◽  
Superior Performance ◽  
Control Performance ◽  
Proportional Integral Derivative ◽  
Content Type ◽  
Proportional Integral ◽  
Avr System ◽  
Optimization Parameters ◽  
Fractional Order Pid

Purpose The purpose of this paper is to improve transient response and dynamic performance of automatic voltage regulator (AVR). Design/methodology/approach This paper proposes a novel fractional order proportional–integral–derivative plus derivative (PIλDµDµ2) controller called FOPIDD for AVR system. The FOPIDD controller has seven optimization parameters and the equilibrium optimizer algorithm is used for tuning of controller parameters. The utilized objective function is widely preferred in AVR systems and consists of transient response characteristics. Findings In this study, results of AVR system controlled by FOPIDD is compared with results of proportional–integral–derivative (PID), proportional–integral–derivative acceleration, PID plus second order derivative and fractional order PID controllers. FOPIDD outperforms compared controllers in terms of transient response criteria such as settling time, rise time and overshoot. Then, the frequency domain analysis is performed for the AVR system with FOPIDD controller, and the results are found satisfactory. In addition, robustness test is realized for evaluating performance of FOPIDD controller in perturbed system parameters. In robustness test, FOPIDD controller shows superior control performance. Originality/value The FOPIDD controller is introduced for the first time to improve the control performance of the AVR system. The proposed FOPIDD controller has shown superior performance on AVR systems because of having seven optimization parameters and being fractional order based.

The influence of sampling frequency and interpolation on the bit error rate of GMSK signal

2021 ◽  
pp. 108-114
Author(s):  
D.D. Privalov
Keyword(s):  
Signal Detection ◽  
Bit Error Rate ◽  
Error Rate ◽  
Clock Synchronization ◽  
Additive White Gaussian Noise ◽  
Sampling Rate ◽  
Digital Signal ◽  
Sampling Frequency ◽  
Synchronization Error ◽  
Minimum Number

The sampling rate at a given bit rate is a requirement for the speed of digital signal processors. In this regard, it is necessary to strive to reduce it in the development of electronic devices, especially portable ones. However, this can lead to an increase in the bit error rate during signal detection. Therefore, it is important to determine the degradation of signal detection with decreasing sampling frequency and to develop practical recommendations to ensure the specified quality of communication. The aim of the article is to study the influence of sampling frequency and interpolation on the bit error rate of GMSK Signal. The article considers the incoherent detection of a GMSK signal in a channel with additive white Gaussian noise, taking into account the influence of the clock synchronization error. Numerical results are presented that characterize an increase in the bit error rate with a decrease in the signal sampling frequency. It is shown that when using the cubic Farrow interpolator, there is no significant degradation in the bit error probability. The minimum number of samples per symbol is determined, at which the bit error rate is close to the theoretical values in the absence of synchronization error. The presented results can be used in development of wireless data transmission systems.

Adaptive synchronization of uncertain fractional-order chaotic systems using sliding mode control techniques

2019 ◽  
Vol 234 (1) ◽  
pp. 3-9 ◽  
Author(s):  
Bahram Yaghooti ◽  
Ali Siahi Shadbad ◽  
Kaveh Safavi ◽  
Hassan Salarieh
Keyword(s):  
Control System ◽  
Sliding Mode Control ◽  
Fractional Order ◽  
Chaotic Systems ◽  
Closed Loop ◽  
Sliding Mode ◽  
Closed Loop Control ◽  
Loop Control ◽  
Closed Loop Control System ◽  
Loop Control System

In this article, an adaptive nonlinear controller is designed to synchronize two uncertain fractional-order chaotic systems using fractional-order sliding mode control. The controller structure and adaptation laws are chosen such that asymptotic stability of the closed-loop control system is guaranteed. The adaptation laws are being calculated from a proper sliding surface using the Lyapunov stability theory. This method guarantees the closed-loop control system robustness against the system uncertainties and external disturbances. Eventually, the presented method is used to synchronize two fractional-order gyro and Duffing systems, and the numerical simulation results demonstrate the effectiveness of this method.

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