Master-slave Network Research Articles

Finite-Time Synchronization Criteria for Caputo Fractional-Order Uncertain Memristive Neural Networks with Fuzzy Operators and Transmission Delay Under Communication Feedback

Unlike existing memristive neural networks or fuzzy neural networks, this article investigates a class of Caputo fractional-order uncertain memristive neural networks (CFUMNNs) with fuzzy operators and transmission delay to realistically model complex environments. Especially, the fuzzy symbol AND and the fuzzy symbol OR as well as nonlinear activation behaviors are all concerned in the generalized master-slave networks. Based on the characteristics of the neural networks being studied, we have designed distinctive information feedback control protocols including three different functional sub-modules. Combining comparative theorems, inequality techniques, and stability theory, novel delay-independent conditions can be derived to ensure the finite-time synchronization (FTS) of fuzzy CFUMNNs. Besides, the upper bound of the settling time can be effectively evaluated based on feedback coefficients and control parameters, which makes the achievements of this study more practical for engineering applications such as signal encryption and secure communications. Ultimately, simulation experiments show the feasibility of the derived results.

Develop an RS-485 Protocol for Arduino Boards Applied To Networked Real Time Control Systems

The Arduino microprocessor boards such as Mega 2560, UNO R3, Leonardo, Micro, and Nano are simple and low-cost tools for real-time measurement and control applications. These Arduino boards cannot be used in distributed systems because they lack the networking capabilities to transfer data across units. In this study, an RS-485 protocol for Arduino boards that operate in Master-Slave networks was developed. Network operations could be carried out independently on the main thread program, and devices in the network could react quickly to information received. This was made possible by the asynchronous serial communication feature and a high-speed timer provided in Arduino boards. The networks designed in this study were applied to an electric vehicle model with all-wheel drive and all-wheel steering capabilities for supermaneuverability as well as a saltwater intrusion early warning system installed in a river entry. The results showed that highly reliable and stable network operations could be achieved, thus extending the usage of popular Arduino boards for networked real-time applications.

A Matching Optimization Method of Distribution Power Internet of Things Based on Network Looseness

Power line carrier communication (PLC) is one of the important technologies to construct and realize ubiquitous power Internet of Things, while the degree of network matching severely affects the communication quality of the network. Combined with the actual topology of a medium voltage (MV) distribution network, the transmission line theory is used to derive the impedance matching relationship between the two slave nodes in the master-slave network mode. Based on this, a matching optimization method for the carrier communication of MV distribution Internet of Things based on network looseness is proposed. Firstly, a large complex distribution communication network is selected and divided into several small impedance-matching networks according to the network looseness on the trunk lines. Then, in each region, the particle swarm algorithm is applied for matching coordination to avoid power wasting and impedance mismatching among multiple communication nodes. The coordinated matching method has fast optimization speed and strong portability, and its feasibility and effectiveness are verified by theoretical derivation, simulation and laboratory test results, which provides an important theoretical basis for the planning, design and popularization of PLC technology in the ubiquitous power Internet of Things.

A generalized phase resetting method for phase-locked modes prediction.

We derived analytically and checked numerically a set of novel conditions for the existence and the stability of phase-locked modes in a biologically relevant master-slave neural network with a dynamic feedback loop. Since neural oscillators even in the three-neuron network investigated here receive multiple inputs per cycle, we generalized the concept of phase resetting to accommodate multiple inputs per cycle. We proved that the phase resetting produced by two or more stimuli per cycle can be recursively computed from the traditional, single stimulus, phase resetting. We applied the newly derived generalized phase resetting definition to predicting the relative phase and the stability of a phase-locked mode that was experimentally observed in this type of master-slave network with a dynamic loop network.

Timestamp Free Synchronization With Sub-Tick Accuracy in the Presence of Discrete Clocks

Timestamp free clock synchronization in a master–slave network, i.e., synchronization where no timestamps are exchanged between the nodes, is considered. For highly accurate synchronization, a novel discrete-valued clock model is introduced. It is based on the observation that clocks are discrete counters in digital wireless radios. Considering this model, it is shown that the round-trip time (RTT) measurements follow specific pulse or step shaped functions. The estimated parameters of these RTT functions are used to determine the clock parameters (clock skew and phase) and the propagation delay. Numerical analysis illustrate that when RTT measurements are collected using discrete-valued clocks, the proposed estimation schemes outperform estimators derived from the continuous clock model, which is used in the state-of-the-art methods. Moreover, the presented scheme performs similar to recently presented discrete-valued clock approaches with more stringent hardware assumption. The correctness of the proposed models is validated through hardware experiments.

Operator Dynamics Consideration for Less Conservative Coupled Stability Condition in Bilateral Teleoperation

Bilateral teleoperation control systems are designed for guaranteed stability against uncertainties in operator and environment dynamics. In this paper, we study the effect of human operator dynamics on the coupled stability by incorporating the operator dynamics in the master–slave network. We will analytically prove and graphically show that for any potentially unstable control architecture, as the operator minimum damping grows, the teleoperation system can stably tolerate a larger range of variations in the environment impedance parameters. More importantly, we will demonstrate how the proposed coupled stability analysis method can be utilized to design stabilizing controllers for enhanced transparency, given a priori knowledge or online estimate of human operator damping.

Distributed Cross-Direction Control System Based on CAN-Bus

A distributed cross-direction control system based on CAN-bus was designed to solve the large-scale cross-direction control problem for paper machine. Multiple Master-Slave CAN networks were constructed in parallel to coordinate and control multiple array actuators, and the Ethernet/CAN converter was used to connect the monitoring station with the field intelligent actuators. The monitoring station accesses measured data and field data via OPC technology. A CAN application layer protocol and corresponding underlying communication software were designed according to the characteristics of the cross-direction control processes. Finally, the feasibility and reliability of the system were verified with practical applications.

Balance Control System Using Microcontrollers for a Rotational Inverted Pendulum

Abstract The paper proposes a low cost solution of the balance/stabilizing system for a rotational inverted pendulum. The hardware implementation consists in a multiple microcontroller platform. Due the plant complexity a fuzzy-PD control algorithm was designed and tested to maintain the pendulum in the unstable upright position. In order to increase the computing speed a I2C master-slave network was chosen for the communication between the components of the control loop. The evolutions of the functional signals are recorded and monitorized by a Labview Interface via RS232 serial communication.

Design of DC Power Line Communication System Using Time-Division Multiplexing

This work investigates a power line communication (PLC) in a DC power management system comprising master-slave control networks. Microcontroller-based master and slave units are designed with serial ports for communication with a controller and a transmission port to couple the signal to modems at both ends. However, coupling data signals to power line through modulation interfacing circuits is a challenging task. In this work, we used time-division multiplexing (TDM) technique to divide into two timings, Powering Time and Communication Time, on the DC power line and can reduce the complexity of the master-slave network and noise effect on the power line.

Modeling of IEEE1588 on OPNET and Analysis of Asymmetric Synchronizing Error in Smart Substation

The IEEE1588 network time synchronization, matched with smart substation information network transmission, is becoming the next generation advanced data synchronization of the smart substation. It is known that the inherent asymmetry error of the network synchronization approach in the smart substation is highlighted, which is concerned particularly. This paper models the synchronization process of the IEEE1588 based on the communication simulation software of OPNET Modeler. Firstly, it builds the models of master-slave clock, IEEE1588 protocol and network synchroniza- tion model, and analyzes the composition and influencing factors of the asymmetry error. Secondly, it quantitatively analyzes the influence of the synchronous asymmetric error of the IEEE1588 affected by the network status differences and the clock synchronization signal transmission path differences. Then its correction method is analyzed, in order to improve the IEEE1588 synchronization reliability and gives the solutions to its application in smart substation.

Using an Evolutionary Denoising Approach to Improve the Robustness of Chaotic Synchronization

Chaotic synchronization in master-slave networks has been extensively studied in the last years, with a relevant impact in application domains like communication systems and the modeling of neuronal and other biomedical signals and systems. Many recent papers have shown that chaotic synchronization is easily lost when there is additive noise in the link between master and slave. This lack of robustness can simply derail the use of chaos-based communication systems in non-ideal environments. In the present work we employ a bio-inspired optimization technique to increase the signal-to-noise-ratio of the chaotic signal that arrives in the slave node of a master-slave discrete-time network and we show that this technique can improve the robustness of the chaotic synchronization to noise.

A Distributed QoS Routing Algorithm for Broadband PLC Networks

Broadband power line (BPLC) network is used power line to transmit data and considered as a kind of no new wired network. The master slave network structure is often used in BPLC networks. As the channel of the BPLC is time-variant, the topology of BPLC networks is dynamically changed. As the application and connection with the Internet increase rapidly, it demands BPLC networks to support Quality of Service (QoS). In this paper, a formulation is given to describe the problem of QoS routing. And then a distributed QoS routing algorithm (DQRA) is proposed. The proof of correctness and complexity analysis of the DQRP are given, the up limit running time of the algorithm is O(H|V| 2 ) .

Chaotic Synchronization in Discrete-Time Systems Connected by Bandlimited Channels

Due to the broadband characteristic of chaotic signals, many of the methods that have been proposed for synchronizing chaotic systems do not usually present a satisfactory performance when applied to bandlimited communication channels. Here, the effects of bandwidth limitations imposed by the channel on the synchronous solution of a discrete-time chaotic master-slave network are investigated. The discrete-time system considered in this study is the Hénon map. It is analytically shown that synchronism can be achieved in such a network by introducing a digital filter in the feedback loop responsible for generating the chaotic signal that will be sent to the slave node. Numerical simulations relating the filter parameters, such as its order and cut-off frequency, to the maximum Lyapunov exponent of the master node, which determines if the transmitted signal is chaotic or not, are also presented. These results can be useful for practical communication schemes based on chaos.

Shared control architectures for haptic training: Performance and coupled stability analysis

A novel shared control architecture is presented for dual-user haptic training simulation systems for enhanced interaction between the users and between each user and the virtual environment. The coupled stability of the proposed control architecture against uncertainties in the environment and the user’s dynamics is investigated using the three-port master–slave network model of the dual-user haptic simulation system. For this purpose, Llewellyn’s unconditional stability criterion is applied to an equivalent two-port network model obtained from the corresponding three-port network, considering the environment as a load termination. The kinesthetic performance of the proposed architecture is numerically analyzed for transparency and evaluated against a benchmark control architecture under different operating conditions, such as various types of environments, users’ grasps, and levels of dominance of users over the task. An experimental user study is carried out to assess the effectiveness of the proposed architecture in terms of users’ perception of environment stiffness sensing, device agility, and haptic guidance reception.

Design constraints for third-order PLL nodes in master-slave clock distribution networks

Clock signal distribution in telecommunication commercial systems usually adopts a master-slave architecture, with a precise time basis generator as a master and phase-locked loops (PLLs) as slaves. In the majority of the networks, second-order PLLs are adopted due to their simplicity and stability. Nevertheless, in some applications better transient responses are necessary and, consequently, greater order PLLs need to be used, in spite of the possibility of bifurcations and chaotic attractors. Here a master-slave network with third-order PLLs is analyzed and conditions for the stability of the synchronous state are derived, providing design constraints for the node parameters, in order to guarantee stability and reachability of the synchronous state for the whole network. Numerical simulations are carried out in order to confirm the analytical results.

Route to chaos in a third-order phase-locked loop network

Phase-locked loops (PLLs) are widely used in applications related to control systems and telecommunication networks. Here we show that a single-chain master–slave network of third-order PLLs can exhibit stationary, periodic and chaotic behaviors, when the value of a single parameter is varied. Hopf, period-doubling and saddle–saddle bifurcations are found. Chaos appears in dissipative and non-dissipative conditions. Thus, chaotic behaviors with distinct dynamical features can be generated. A way of encoding binary messages using such a chaos-based communication system is suggested.

A Master-Slave Neural Network for precise recognition of the complicated hand operations based on EEG

On the basis of excellent features of the Hopfield neural network, a new Master-Slave Neural Network (simply denoted as MSNN) model was presented in this paper. The structure of the proposed MSNN was first designed, and the corresponding training algorithm was discussed in detail, and the stability of the MSNN was analysed in detail. Finally, through a two-channel EEG measurement system set-up, and the feature of the related EEG signals extracted, some complicated hand operations were recognised by using the MSNN and BP neural network. The comparison showed that the MSNN had a better asymptotic convergence rate and a higher mapping precision, so that a higher recognition possibility was achieved than the BP network. This is an expanded version of a paper presented at the 3rd IEEE International Workshop on Medical Measurements and Applications, 9 10 May 2008, Ottawa, ON, Canada.

Modeling and measuring double-frequency jitter in one-way master–slave networks

The double-frequency jitter is one of the main problems in clock distribution networks. In previous works, some analytical and numerical aspects of this phenomenon were studied and results were obtained for one-way master-slave (OWMS) architectures. Here, an experimental apparatus is implemented, allowing to measure the power of the double-frequency signal and to confirm the theoretical conjectures.

IEEE802.11 Sensor Networking

This paper deals with a smart-transducer wireless network for industrial applications. Thanks to its high popularity, a solution based on IEEE802.11 (also known as wireless fidelity or Wi-Fi) is experimentally investigated. A master-slave network organization is proposed to allow several sensors to be connected with generic Wi-Fi devices like PCs; a proprietary protocol over Internet Protocol (IP)/User Datagram Protocol (UDP) has also been developed. Last, some low-cost prototypes have been built to test the network behavior performances in terms of timing characteristics and power dissipation. Experimental results prove the applicability in a soft real-time (nontime-critical) industrial context.

Two-way master-slave double-chain networks: limitations imposed by linear master drift for second order PLLs as slave nodes

Distribution of precise time signals among the nodes of a network is a fundamental requirement for digital transmission and switching systems in telecommunication and control. Cideciyan et al., (1987) conjectured that two-way master-slave (TWMS) networks present, in the general case, a better performance than one-way master-slave (OWMS) considering the long term linear master frequency drift. In this work we study the TWMS case using dynamical system theory showing that, due to the effects of long-term clock instabilities, the steady-state frequency-error is unstable for a number of slaves higher or equal than four, limiting the use of this kind of architecture.