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1 – 10 of over 1000Redha Benachour, Saïda Latreche, Mohamed El Hadi Latreche and Christian Gontrand
The present work aims to explain how the nonlinear average model can be used in power electronic integration design as a behavioral model.
Abstract
Purpose
The present work aims to explain how the nonlinear average model can be used in power electronic integration design as a behavioral model.
Design/methodology/approach
The nonlinear average model is used in power electronic integration design as a behavioral model, where it is applied to a voltage source inverter based on IGBTs. This model was chosen because it takes into account the nonlinearity of the power semiconductor components and the wiring circuit effects, which can be formalized by the virtual delay concept. In addition, the nonlinear average model cannot distinguish between slow and quick variables and this is an important feature of the model convergence.
Findings
The paper studies extensively the construction of the nonlinear average model algorithm theoretically. Detailed explanations of the application of this model to voltage source inverter design are provided. The study demonstrates how this model illustrates the effect of the nonlinearity of the power semiconductor components' characteristics on dynamic electrical quantities. It also predicts the effects due to wiring in the inverter circuit.
Research limitations/implications
More simulations and experimental analysis are still necessary to improve the model's accuracy, by using other static characteristic approaches, and to validate the applicability of the model to different converter topologies.
Practical implications
The paper formulates a simple nonlinear average model algorithm, discussing each step. This model was described by VHDL‐AMS. On the one hand, it will assist theoretical and practical research on different topologies of power electronic converters, particularly in power integration systems design such as the integrated power electronics modules (IPEM). On the other hand, it will give designers a more precise behavioral model with a simpler design process.
Originality/value
The nonlinear average model used in power electronic integration design as behavioral model is a novel approach. This model reduces computational costs significantly, takes physical effects into account and is easy to implement.
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Yushing Cheung and Jae H. Chung
This paper aims to make an industrial robot intelligently and remotely cooperate with humans to work in unknown unstructured environments.
Abstract
Purpose
This paper aims to make an industrial robot intelligently and remotely cooperate with humans to work in unknown unstructured environments.
Design/methodology/approach
Presents a bilateral adaptive teleoperation control approach involving a contact force driven compensation with an auto‐switching function, which utilizes a biologically motivated compliance function. Based on sensed contact force, the switching function can adjust its slave control input to decide how much robotic intelligences should intervene in the system by switching modes. Other schemes for robotic intelligence, robotic impedances and compensators, are investigated to guarantee good transparency without warranting human error and maintain a stable contact, based on the force feedback, in constrained motion while a communication delay exists.
Findings
The simulation and experimental results demonstrate transparency and contact stability in the presence of constant and time‐varying communication delays, respectively. The proposed bilateral adaptive teleoperation control method outperforms three other techniques.
Originality/value
This paper introduces an adaptive teleoperation control method with local robotic intelligence assistance. The developed method does not modify the existing designs of industrial robots. The contact force and position and force errors are well controlled to obtain a stable contact and transparency, through adaptation of robotic impedances.
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Bikramaditya Das, Bidyadhar Subudhi and Bibhuti Bhusan Pati
The purpose of this paper is to propose development of a formation control algorithm by employing a nonlinear observer for compensating the delay in the sensor signal transmission…
Abstract
Purpose
The purpose of this paper is to propose development of a formation control algorithm by employing a nonlinear observer for compensating the delay in the sensor signal transmission to the controller arising due to packet dropout in acoustic medium.
Design/methodology/approach
A robust control law is developed using the sliding mode approach integrated with a communication consensus algorithm for achieving cooperative motion of acoustic underwater vehicles in a group ensuring the transfer of information among the AUVs. In acoustic medium, inter-vehicle communication is challenging for a group of AUVs deployed in formation because underwater channel encounter a number of constraints such as low data rate, packet delays and dropouts.
Findings
It is observed that the sliding mode control-unscented Kalman filter formation control exhibits superior control performance such as mitigating larger initial error of estimation and removing the use of the Jacobian matrices among the three controllers developed. The proposed nonlinear observer estimates the un-measureable states such as position in x, y and z-axes, heading, rudder and sturn angle, needed for generating the formation control. A simulation setup is realized to demonstrate the performance of the proposed observer-based formation controller. Simulations were performed in MATLAB and the obtained results are analysed and compared which envisage that the proposed control algorithm provides efficient formation control under the acoustic communication constraints.
Originality/value
Development of observer for achieving formation control of AUVs in underwater area – common reference velocity and error signals being available to all cooperating AUVs – UKO performs better based on initial error estimation and tracking the same path in shallow water area.
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This article provides a broad overview of telecommunications and network‐related technologies. Topics covered include identification and review of network elements, analog and…
Abstract
This article provides a broad overview of telecommunications and network‐related technologies. Topics covered include identification and review of network elements, analog and digital signals, synchronous and asynchronous transmission formats, transmission media and equipment, transmission techniques and characteristics, multiplexing, network types, access technologies, network architectures and topologies, local‐area network technologies and attributes, protocols and protocol issues, gateways, internetworking, local networking alternatives, equipment certification, and various aspects of network management. It is intended to provide the practicing professional in the field of library and information science with a broad, up‐to‐date technical review that might serve to support and facilitate further investigation of current developments in networks and networking. Although the broad range of topics is not treated in depth, numerous references are provided for further investigation.
Compared to the traditional wireless network, the multi‐hop ad hoc wireless network is self‐configurable, dynamic, and distributed. During the past few years, many routing…
Abstract
Compared to the traditional wireless network, the multi‐hop ad hoc wireless network is self‐configurable, dynamic, and distributed. During the past few years, many routing protocols have been proposed for this particular network environment. While in wired and optical networks, multi‐protocol label switching (MPLS) has clearly shown its advantages in routing and switching such as flexibility, high efficiency, scalability, and low cost. However MPLS is complex and does not consider the mobility issue for wireless networks, especially for ad hoc wireless networks. This paper migrates the label concept into the ad hoc network and provides a framework for the efficient label routing protocol(LRP) in such a network. The MAC layer is also optimized with LRP for shorter delay, power saving, and higher efficiency. The simulation results show that the delay is improved significantly with this cross‐layer routing protocol.
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Brian P. DeJong, Eric L. Faulring, J. Edward Colgate, Michael A. Peshkin, Hyosig Kang, Young S. Park and Thomas F. Ewing
Sets out to discuss lessons learned from the creation and use of an over‐the‐internet teleoperation testbed.
Abstract
Purpose
Sets out to discuss lessons learned from the creation and use of an over‐the‐internet teleoperation testbed.
Design/methodology/approach
Seven lessons learned from the testbed are presented.
Findings
This teleoperation interface improves task performance, as proved by a single demonstration.
Originality/value
In helping to overcome time‐delay difficulties in the operation, leading to dramatically improved task performance, this study contributes significantly to the improvement of teleoperation by making better use of human skills.
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Sujata S.B. and Anuradha M. Sandi
The small area network for data communication within routers is suffering from storage of packet, throughput, latency and power consumption. There are a lot of solutions to…
Abstract
Purpose
The small area network for data communication within routers is suffering from storage of packet, throughput, latency and power consumption. There are a lot of solutions to increase speed of commutation and optimization of power consumption; one among them is Network-on-chip (NoC). In the literature, there are several NoCs which can reconfigurable dynamically and can easily test and validate the results on FPGA. But still, NoCs have limitations which are regarding chip area, reconfigurable time and throughput.
Design/methodology/approach
To address these limitations, this research proposes the dynamically buffered and bufferless reconfigurable NoC (DB2R NoC) using X-Y algorithm for routing, Torus for switching and Flexible Direction Order (FDOR) for direction finding between source and destination nodes. Thus, the 3 × 3 and 4 × 4 DB2R NoCs are made free from deadlock, low power and latency and high throughput. To prove the applicability and performance analysis of DB2R NoC for 3 × 3 and 4 × 4 routers on FPGA, the 22 bits for buffered and 19 bit for bufferless designs have been successfully synthesized using Verilog HDL and implemented on Artix-7 FPGA development bond. The virtual input/output chips cope pro tool has been incorporated in the design to verify and debug the complete design on Artix-7 FPGA.
Findings
In the obtained result, it has been found that 35% improvement in throughput, 23% improvement in latency and 47% optimization in area has been made. The complete design has been tested for 28 packets of injection rate 0.01; the packets have been generated by using NLFSR.
Originality/value
In the obtained result, it has been found that 35% improvement in throughput, 23% improvement in latency and 47% optimization in area has been made. The complete design has been tested for 28 packets of injection rate 0.01; the packets have been generated by using NLFSR.
Details
Keywords
Dennis G. Perry, Steven H. Blumenthal and Robert M. Hinden
The ARPANET, initiated in 1969 by the Advanced Research Projects Agency (DARPA) of the Department of Defense (DoD), was the first wide area packet switching network. In 1984, the…
Abstract
The ARPANET, initiated in 1969 by the Advanced Research Projects Agency (DARPA) of the Department of Defense (DoD), was the first wide area packet switching network. In 1984, the ARPANET, which had grown to over 100 nodes, was separated into two parts: an operational component, the MILNET, to serve the operational needs of the DoD, and a research component that retained the ARPANET name. After the network split, the MILNET expanded, and it should reach over 250 nodes within a year. The DARPA Internet was formed in the 1970s in response to a requirement to interconnect different types of packet‐switching networks that were being implemented. It has grown to be very large; it now consists of over 330 networks, hundreds of gateways, and tens of thousands of hosts. Where the ARPANET used to connect hosts that were single computers into a network, many of these hosts now serve as gateways to local campus networks, regional networks, and other national networks, such as the NSFNET. The impact of this growing system of inter‐connected networks on research, communications, and library access will be profound.