Design and Implementation of Distributed Controller Clustering for Solving the Issue of Single Failure in SDN Networks

Software-Defined Networks (SDN) It is a centralized control structure in the network that opens up new possibilities that did not exist before. The significant characteristic of this innovative approach is the focus on the capability of proposing networks of high dynamicity and programmability to transform the intelligence of underlying systems to the networks via controllers. The main issue of the SDN approach is found in its security, mainly due to its central-controlling architecture since the entire network is controlled from a central point. This makes it very vulnerable to single-point failure. In this paper, a fully Distributed SDN controller is proposed for solving the one point failure which exists within the single SDN controller. In general, the concept involves forming cluster of distributed controllers whereby each controller controls its domain and can thereby share the load within the network. The experimental results of the proposed system show an increase and enhancement in the performance of the network. The single-point failure issues have been overcome. The throughput of the proposed system increased with 20% while the packet loss rate was minimize with 33%.

Velocity-free distributed geometric formation control for underactuated UAVs

Purpose This paper aims to investigate the distributed formation control problem for a multi-quadrotor unmanned aerial vehicle system without linear velocity feedbacks. Design/methodology/approach A nonlinear controller is proposed based on the orthogonal group SE(3) to obviate singularities and ambiguities of the traditional parameterized attitude representations. A cascade structure is applied in the distributed controller design. The inner loop is responsible for attitude control, and the outer loop is responsible for translational dynamics. To ensure a linear-velocity-free characteristic, some auxiliary variables are introduced to construct virtual signals in distributed controller design. The stability analysis of the proposed distributed control method by the Lyapunov function is provided as well. Findings A group of four quadrotors with constant reference linear velocity and a group of six quadrotors with varying reference linear velocity are adopted to verify the effectiveness of the proposed strategy. Originality/value This is a new innovation for multi-robot formation control method to improve assembly automation.

Dynamical distributed controller for the synchronization problem of integer and fractional order partial differential equation systems

In this work we present a methodology to design dynamical distributed controllers for the synchronization problem of systems governed by partial differential equations of integer and fractional order. We consider fractional systems whose space derivatives are of integer order and time derivatives are of fractional commensurate order. The methodology is based on finding canonical forms by means of a change of variable, such that a distributed controller can be designed in a natural way in the form of a chain of integrators. To study the stability of the integer order closed loop system, we propose to use the spectral and semi-group theory for infinite dimensional Hilbert spaces. On the other hand, the stability criterion previously established by Matignon is used for the stability analysis of the fractional order case. Additionally, we tackle the synchronization problem of multiple systems, which is reduced to a problem of generalized multi-synchronization. To illustrate the effectiveness of the proposed methodology, examples and numerical results are given.

An Emperor Penguin Optimization and Particle Swarm Optimization Control algorithm for PV with ZSI in Grid Connected System

In the paper, a distributed controller for the analysis of SEPIC and Z-Source Inverter (ZSI) based grid-connected Photovoltaic (PV) system. The PV systems are modeled, designed and implemented to given maximum power output with the help of proposed controller. In the paper, a distributed controller is designed to provide maximum output power and to working by changing irradiance and providing various range of active power. An enhanced controller is specified as the Fractional Order PID (FOPID) controller with aid of hybrid approach. The hybrid approach is consisting of Emperor Penguin Optimization (EPO) and Particle Swarm Optimization (PSO). FOPID controller is the advanced PID controller and it gives a better output and robustness than the traditional PID controller. To enhance the performance of the FOPID, the gain parameters are optimized with the utilization of hybrid approach. For achieving the optimal power management and maximum power tracking, the objective function is defined and specified their constraints also. Here, two various methods have been deliberated to changing the inverter operation with constant irradiance and varied irradiance. The proposed method is tested by using MATLAB/Simulink and it is contrasted with the previously developed methods like base model, Ant Colony Optimization (ACO) and PSO algorithm.