ICMA: AN EFFICIENT INTEGRATED CONGESTION CONTROL APPROACH

2019 ◽  
Vol 14 ◽  
Author(s):  
Tayyab Khan ◽  
Karan Singh ◽  
Kamlesh C. Purohit

Background: With the growing popularity of various group communication applications such as file transfer, multimedia events, distance learning, email distribution, multiparty video conferencing and teleconferencing, multicasting seems to be a useful tool for efficient multipoint data distribution. An efficient communication technique depends on the various parameters like processing speed, buffer storage, and amount of data flow between the nodes. If data exceeds beyond the capacity of a link or node, then it introduces congestion in the network. A series of multicast congestion control algorithms have been developed, but due to the heterogeneous network environment, these approaches do not respond nor reduce congestion quickly whenever network behavior changes. Objective: Multicasting is a robust and efficient one-to-many (1: M) group transmission (communication) technique to reduced communication cost, bandwidth consumption, processing time and delays with similar reliability (dependability) as of regular unicast. This patent presents a novel and comprehensive congestion control method known as integrated multicast congestion control approach (ICMA) to reduce packet loss. Methods: The proposed mechanism is based on leave-join and flow control mechanism along with proportional integrated and derivate (PID) controller to reduce packet loss, depending on the congestion status. In the proposed approach, Proportional integrated and derivate controller computes expected incoming rate at each router and feedback this rate to upstream routers of the multicast network to stabilize their local buffer occupancy. Results: Simulation results on NS-2 exhibit the immense performance of the proposed approach in terms of delay, throughput, bandwidth utilization, and packet loss than other existing methods. Conclusion: The proposed congestion control scheme provides better bandwidth utilization and throughput than other existing approaches. Moreover, we have discussed existing congestion control schemes with their research gaps. In the future, we are planning to explore the fairness and quality of service issue in multicast communication.

2008 ◽  
Vol 18 (08) ◽  
pp. 2319-2344
Author(s):  
AHMED OTEAFY ◽  
MOHAMED ZRIBI ◽  
NEJIB SMAOUI

This paper presents an approach to control the chaotic dynamics of discrete-time (or discretizable) systems. The objective of the paper is to focus on the suppression of the chaotic dynamics and the restoration of order with a state feedback controller. The proposed control method works by targeting instantaneous measures of the Lyapunov exponents of a system and setting them to desired values. At first, the paper presents an instantaneous measure of the Lyapunov exponents; this measure is used to control the system's dynamics. Then, the formulation of the control algorithm to suppress chaos is presented. Two cases for the control structure are considered. The first case corresponds to the case when the number of control inputs is equal to the number of states; the second case corresponds to the case when the number of control inputs is less than the number of states. The Lorenz system, the smooth Chua Oscillator system, the Rössler-hyperchaos system and a fourth order chaotic oscillator system are used as examples to illustrate the proposed control scheme. The simulation results show the efficacy of the proposed control approach.


2021 ◽  
Vol 21 (10) ◽  
pp. 253
Author(s):  
Cong-Ming Shi ◽  
Hui Deng ◽  
Feng Wang ◽  
Ying Mei ◽  
Shao-Guang Guo ◽  
...  

Abstract Data archiving is one of the most critical issues for modern astronomical observations. With the development of a new generation of radio telescopes, the transfer and archiving of massive remote data have become urgent problems to be solved. Herein, we present a practical and robust file-level flow-control approach, called the Unlimited Sliding-Window (USW), by referring to the classic flow-control method in the TCP protocol. Based on the USW and the Next Generation Archive System (NGAS) developed for the Murchison Widefield Array telescope, we further implemented an enhanced archive system (ENGAS) using ZeroMQ middleware. The ENGAS substantially improves the transfer performance and ensures the integrity of transferred files. In the tests, the ENGAS is approximately three to twelve times faster than the NGAS and can fully utilize the bandwidth of network links. Thus, for archiving radio observation data, the ENGAS reduces the communication time, improves the bandwidth utilization, and solves the remote synchronous archiving of data from observatories such as Mingantu spectral radioheliograph. It also provides a better reference for the future construction of the Square Kilometer Array (SKA) Science Regional Center.


2018 ◽  
Vol 24 (23) ◽  
pp. 5570-5584 ◽  
Author(s):  
Seyed Mohammad Ahmadi ◽  
Mohammad Mehdi Fateh

This paper presents a robust task-space control approach using a direct adaptive Taylor series controller for electrically driven robot manipulators. In an adaptive Taylor series control scheme, the parameters of controller are directly tuned in order to reduce the task-space tracking error in the presence of structured and unstructured uncertainty. Also, the upper bound of approximation error is estimated to form a robustifying term and the asymptotic convergence of task-space tracking error and its time derivative is proven based on the stability analysis. Simulation results are included to verify the effectiveness of the proposed control method.


Author(s):  
P. R. Ouyang ◽  
W. J. Zhang ◽  
Madan M. Gupta

In this paper, a new adaptive switching control approach, called adaptive evolutionary switching PD control (AES-PD), is proposed for iterative operations of robot manipulators. The proposed AES-PD control method is a combination of the feedback of PD control with gain switching and feedforward using the input torque profile obtained from the previous iteration. The asymptotic convergence of the AES-PD control method is theoretically proved using Lyapunov’s method. The philosophy of the switching control strategy is interpreted in the context of the iteration domain to increase the speed of the convergence for trajectory tracking of robot manipulators. The AES-PD control has a simple control structure that makes it easily implemented. The validity of the proposed control scheme is demonstrated for the trajectory tracking of robot manipulators through simulation studies. Simulation results show that the AES-PD control can improve the tracking performance with an increase of the iteration number. The EAS-PD control method has the adaptive and learning ability; therefore, it should be very attractive to applications of industrial robot control.


Author(s):  
Mitsutaka Kimura ◽  
Mitsuhiro Imaizumi ◽  
Toshio Nakagawa

This paper discusses the reliability model of a window flow control scheme using High-performance and Flexible Protocol (HpFP) with Explicit Congestion Notification (ECN) considering packet loss. HpFP is an important techniques as congestion control scheme in a radio environment and video stream communication. HpFP has the character that throughput is adjusted by changing a packet transmission interval. We have already discussed some reliability models of a window flow control scheme based on a packet transmission interval. In these models, if some packets has failed at a first-time transmission, the packet transmission interval is prolonged. On the other hand, the server checks the state of network congestion by ECN bit. That is, if ECN bit has been set during connection, a packet transmission interval is also prolonged. We consider an extended stochastic model of a window flow control scheme based on a packet transmission interval with ECN considering packet loss. That is, the server checks ECN bit during connection and if the server detects the network congestion, the server executes congestion control that a packet transmission interval is prolonged. Thereafter, if a constant number of the retransmission has failed, or a constant number of packets has failed, the server checks it again. We derive the mean time until packet transmissions succeed, and discuss analytically a window size which maximizes the amount of packets per unit of mean transmission time.


Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4563
Author(s):  
Muhammad Ali ◽  
Ghulam Hafeez ◽  
Ajmal Farooq ◽  
Zeeshan Shafiq ◽  
Faheem Ali ◽  
...  

This paper proposes a hybrid control scheme for a newly devised hybrid multilevel inverter (HMLI) topology. The circuit configuration of HMLI is comprised of a cascaded converter module (CCM), connected in series with an H-bridge converter. Initially, a finite set model predictive control (FS-MPC) is adopted as a control scheme, and theoretical analysis is carried out in MATLAB/Simulink. Later, in the real-time implementation of the HMLI topology, a hybrid control scheme which is a variant of the FS-MPC method has been proposed. The proposed control method is computationally efficient and therefore has been employed to the HMLI topology to mitigate the high-frequency switching limitation of the conventional MPC. Moreover, a comparative analysis is carried to illustrate the advantages of the proposed work that includes low switching losses, higher efficiency, and improved total harmonic distortion (THD) in output current. The inverter topology and stability of the proposed control method have been validated through simulation results in MATLAB/Simulink environment. Experimental results via low-voltage laboratory prototype have been added and compared to realize the study in practice.


2014 ◽  
Vol 651-653 ◽  
pp. 812-817 ◽  
Author(s):  
Jian Guo Zheng ◽  
Zhi Gang Zou ◽  
Hui Zeng ◽  
Tian Peng He

There has been wide interest in the control scheme of the electromagnetic levitation system due to its disadvantages of nonlinearity and open-loop uncertainty. A typical coil-ball levitation system is used in research. The forces of the ball are analyzed and a dynamic model of the whole electromagnetic levitation system is established. Based on the nonlinear state-space model, the coil-ball system is linearized and then a LQR control approach is proposed. Simulation results show that, compared with conventional pole assignment scheme, the electromagnetic levitation system under the proposed control approach gets a better performance, including smaller overshot and faster response.


2021 ◽  
Author(s):  
Zhuangbi Lin ◽  
Zhi Liu ◽  
Yun Zhang ◽  
C.L.Philip Chen

Abstract An indirect adaptive consensus control method is presented for MASs with Unknown Bouc-Wen hysteresis states and input. All states of MASs are measured by sensors subjected to hysteresis. In order to reduce the effect of hysteresis with multi-value and rate-dependent characteristics, an adaptive compensated scheme is proposed. NNs are introduced to approximate the time-varying control gain which is coupled by input hysteresis and states hysteresis. The parameters of inverse compensation model are approximated by adaptive laws. The proposed control scheme can guarantee that the consensus errors of followers converge to a predefined interval of zero asymptotically. In addition, the transient performance of MASs can be further ensured. A simulation example is included to verify the effectiveness of the presented control approach.


2021 ◽  
Author(s):  
Yu-Qun Han

Abstract For the first time, the issue of input delays and prescribed performance control is investigated in the same framework for large-scale nonlinear systems in this study, and a original adaptive decentralized control method is proposed take advantage of multi-dimensional Taylor network (MTN) method. Firstly, the problem of input delays is solved by introducing new variables, and a new form of coordinate transformation is introduced before controller design, which simplified the control system. Secondly, the problem of prescribed performance control is coped with by integrating the idea of prescribed performance into the Lyapunov functions of first step of backstepping of each subsystem. Thirdly, MTNs are employed to evaluate the combination of unknown functions, and then a decentralized MTN-based adaptive control scheme is developed by way of backstepping technology. The theoretical analysis indicates that the proposed control scheme can implement the expected tracking goals under the condition of meeting the prescribed performance control. Finally, one numerical example is given to show the validity and rationality of the proposed control method.


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