10,352 research outputs found
A Cross-Layer Approach for Minimizing Interference and Latency of Medium Access in Wireless Sensor Networks
In low power wireless sensor networks, MAC protocols usually employ periodic
sleep/wake schedule to reduce idle listening time. Even though this mechanism
is simple and efficient, it results in high end-to-end latency and low
throughput. On the other hand, the previously proposed CSMA/CA-based MAC
protocols have tried to reduce inter-node interference at the cost of increased
latency and lower network capacity. In this paper we propose IAMAC, a CSMA/CA
sleep/wake MAC protocol that minimizes inter-node interference, while also
reduces per-hop delay through cross-layer interactions with the network layer.
Furthermore, we show that IAMAC can be integrated into the SP architecture to
perform its inter-layer interactions. Through simulation, we have extensively
evaluated the performance of IAMAC in terms of different performance metrics.
Simulation results confirm that IAMAC reduces energy consumption per node and
leads to higher network lifetime compared to S-MAC and Adaptive S-MAC, while it
also provides lower latency than S-MAC. Throughout our evaluations we have
considered IAMAC in conjunction with two error recovery methods, i.e., ARQ and
Seda. It is shown that using Seda as the error recovery mechanism of IAMAC
results in higher throughput and lifetime compared to ARQ.Comment: 17 pages, 16 figure
Implementation of Model Based Networked Predictive Control System
Networked control systems are made up of several computer nodes
communicating over a communication channel, cooperating to control a
plant. The stability of the plant depends on the end to end delay from
sensor to the actuator. Although computational delays within the
computer nodes can be made bounded, delays through the
communication network are generally unpredictable. A method which
aims to protect the stability of the plant under communication delays
and data loss, Model Based Predictive Networked Control System
(MBPNCS), has previously been proposed by the authors. This paper aims
to demonstrate the implementation of this type of networked control
system on a non-real-time communication network; Ethernet.
In this paper, we first briefly describe the MBPNCS method, then
discuss the implementation, detailing the properties of the operating
system, communications and hardware, and later give the results on the
performance of the Model Based Predictive Networked Control System
implementation controlling a DC motor.
This work was supported in part by the Scientific and Technological Re
search Council of Turkey, project code 106E155
Fuzzy-logic-based control, filtering, and fault detection for networked systems: A Survey
This paper is concerned with the overview of the recent progress in fuzzy-logic-based filtering, control, and fault detection problems. First, the network technologies are introduced, the networked control systems are categorized from the aspects of fieldbuses and industrial Ethernets, the necessity of utilizing the fuzzy logic is justified, and the network-induced phenomena are discussed. Then, the fuzzy logic control strategies are reviewed in great detail. Special attention is given to the thorough examination on the latest results for fuzzy PID control, fuzzy adaptive control, and fuzzy tracking control problems. Furthermore, recent advances
on the fuzzy-logic-based filtering and fault detection problems are reviewed. Finally, conclusions are given and some possible future research directions are pointed out, for example, topics on two-dimensional networked systems, wireless networked control systems, Quality-of-Service (QoS) of networked systems, and fuzzy access control in open networked systems.This work was supported in part by the National Natural Science Foundation of China under Grants 61329301,
61374039, 61473163, and 61374127, the Hujiang Foundation of China under Grants C14002 andD15009, the Engineering and Physical Sciences Research Council (EPSRC) of the UK, the Royal Society of the UK, and the Alexander von Humboldt Foundation of Germany
Embedded Network Test-Bed for Validating Real-Time Control Algorithms to Ensure Optimal Time Domain Performance
The paper presents a Stateflow based network test-bed to validate real-time
optimal control algorithms. Genetic Algorithm (GA) based time domain
performance index minimization is attempted for tuning of PI controller to
handle a balanced lag and delay type First Order Plus Time Delay (FOPTD)
process over network. The tuning performance is validated on a real-time
communication network with artificially simulated stochastic delay, packet loss
and out-of order packets characterizing the network.Comment: 6 pages, 12 figure
Cross-Layer Adaptive Feedback Scheduling of Wireless Control Systems
There is a trend towards using wireless technologies in networked control
systems. However, the adverse properties of the radio channels make it
difficult to design and implement control systems in wireless environments. To
attack the uncertainty in available communication resources in wireless control
systems closed over WLAN, a cross-layer adaptive feedback scheduling (CLAFS)
scheme is developed, which takes advantage of the co-design of control and
wireless communications. By exploiting cross-layer design, CLAFS adjusts the
sampling periods of control systems at the application layer based on
information about deadline miss ratio and transmission rate from the physical
layer. Within the framework of feedback scheduling, the control performance is
maximized through controlling the deadline miss ratio. Key design parameters of
the feedback scheduler are adapted to dynamic changes in the channel condition.
An event-driven invocation mechanism for the feedback scheduler is also
developed. Simulation results show that the proposed approach is efficient in
dealing with channel capacity variations and noise interference, thus providing
an enabling technology for control over WLAN.Comment: 17 pages, 12 figures; Open Access at
http://www.mdpi.org/sensors/papers/s8074265.pd
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