On the Maximum Coverage Area of Wireless Networked Control Systems With Maximum Cost-Efficiency Under Convergence Constraint

There is a strong trend towards wireless networked Real-Time Control Systems. However, a variety of factors such as the variability of wireless channel capacities, multi-path fading, and ambient interference make it extraordinarily difficult to design and implement Wireless Control Systems (WCSs). To attack the uncertainty in available communication resource in WCSs, this chapter presents an Adaptive Feedback Scheduling scheme that takes advantage of the methodology of cross-layer design. The proposed approach exchanges information across the physical layer and the application layer in the presence of noise interference and link transmission rate variations. The overall QoC is guaranteed through controlling the deadline miss ratio of control loops. Design parameters of the feedback scheduler are adapted to dynamic changes in wireless channel capacity. To further improve the feedback scheduling performance, an event-driven invocation mechanism for feedback schedulers is suggested. Simulation results demonstrate that this approach is efficient to deal with channel capacity variations and noise interference, thus providing an enabling technology for wireless control in dynamic environments. It is also argued that in this context event-driven invocation mechanism improves the performance of the feedback scheduling system.KeywordsSampling PeriodTransmission RateMedium Access ControlControl PerformanceMedium Access Control ProtocolThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Wireless networked control system (WNCS) is given profound attention because of dynamic, flexibility and inexpensiveness. However, it is difficult to use a single simulator to simulate a WNCS which is a hybrid system. A co-simulation framework based on OPNET, Matlab and C++ is presented to capture both the system dynamics and communication events and depict the real WNCS accurately. MATLAB is good for simulating the mathematical modeling and feedback control, while OPNET is apt at simulating the WLAN communication behavior. The co-simulation framework can help WNCS designer understand and improve the performance of the WNCS.

Connectivity and coverage constrained wireless sensor nodes deployment using steepest descent and genetic algorithms

One promising approach for pixel-wise semantic segmentation is based on higher-order Conditional Random Fields (CKFs). We aim to selectively choose segments for the higher-order CRFs in semantic segmentation. To this end, we formulate the selection as an optimization problem. We propose three optimization criteria in relation to the selected segments, namely: a) averaged goodness, b) coverage area and c) non-overlapped area. Essentially, we desire to have best segments with maximum coverage area and maximum non-overlapped area. We apply two evolutionary optimization algorithms, namely: the genetic algorithm (GA) and the particle swarm optimization (PSO). The goodness of segments is estimated using the Latent Dirichlet Allocation approach. Experiment results show that semantic segmentation with GA-or-PSO-selected segments yields competitive semantic segmentation accuracy in comparison to that of naively using all segments. Moreover, the fewer number of segments used in semantic segmentation speeds up its computation time up to six times faster.

This paper integrates the IEEE 802.11 g ad-hoc wireless network and the control area network (CAN) in the present network control systems (NCS) or wireless - NCS (WNCS). Both the TCP and the CAN protocols are adopted as the communication gateway in a remote control system. The time delay between the application layer of the client and the application layer of the remote control target has been measured and analyzed in this paper. Experimental results on an AC 400 W servo motor indicate that the communication jam mainly causes the instability due to the induced time delay. In this paper, by applying the adaptive Smith predictor with the switching sampling time, satisfactory control performance of WNCS can be obtained even though the time delay seriously increases. Moreover, the feasibility of the proposed WNCS has been proven through experimental results.

Wireless networked control systems (WNCS) over mobile ad hoc network (MANET) is a new area of research and has many potential applications, for instance, military or rescue missions, exploring hazardous environments, and so on. For performance evaluation, researchers mostly rely on computer simulations as WNCS experiments are expensive to execute. It will generate a significant benefit to conduct performance analysis of WNCS over MANET using co-simulation that utilises SIMULINK and OPtimised Network Engineering Tool (OPNET) to simulate plant/controller behaviour and the MANET, respectively. Previous conference papers by the authors reported the initial SIMULINK-OPNET co-simulation for only one network size. Here the authors present an extention of their previous work, and presents the SIMULINK-OPNET co-simulation, methodology and comprehensive simulation results that have not been reported previously. It also considers the impact of five network sizes with stationary and mobile nodes. The proposed SIMULINK-OPNET co-simulation is applied to WNCS over MANET using a realistic wireless communication model. It investigates the impact of network data rates, node mobility, the packet delay, packet drop on the system stability and performance.

In order to effectively restrain the impact of network delays for wireless networked control systems (WNCS), aiming to time-variant, random and uncertain network delays and controlled plant might be time-variant or nonlinear, as well as Smith predictor models might be imprecise, we propose a novel approach that modified Smith predictor combined with fuzzy immune self-regulating PID control for the WNCS. Because modified Smith predictor does not include network delay models, therefore, it is no need for measuring on line, identifying or estimating network delays, thus it is applicable to some occasions that network delays are larger than one, even tens of sampling periods. Based on IEEE 802.11 b/g (WLAN), the results of simulation experiment show validity of the control scheme and improvement in dynamic performance and robustness of the WNCS.

A wireless networked control system (WNCS) consists of a dynamic system to be controlled, sensors, actuators, and a remote controller. A WNCS has two types of wireless transmissions, i.e., the sensor's measurement transmission to the controller and the controller's command transmission to the actuator. In this paper, we are surveying the literature on the communication networks in WNCSs and the challenges related to them, such as the communication standards, delay, Packet dropout, and delay jitter. Then, the control approaches in the design of a WNCS are presented, including the interactive design approaches and the joint design approaches. Also, several applications of WNCSs have been discussed in terms of their structure, functionality, and control design. These applications include Intra-Vehicle Wireless networks, Wireless Avionics Intra-Communication, Building Automation, and Water pumping. After that, security issues in WNCSs from a control engineering point of view are detailed while focusing on the major kinds of cyber attacks affecting WNCSs. Finally, future directions and conclusions are summarized at the end of the paper.

Wireless Network Control Systems (WNCSs) have been developed and deployed in many applications because of the flexibility afforded by the wireless communications medium in accommodating the control loop. In this paper, we examine a wide area WNCS using LTE as the wireless fabric. We introduce a novel concept known as “reflection” which is a subscription model that allows an LTE eNodeB to inform certain nodes in a group about low level radio signalling from certain other nodes in the group before any application data has been sent. The mean Round Trip Time (RTT) for control in an LTE based wide area WNCS which is enhanced for reflection is reduced by at least 6ms compared to a standard LTE based wide area WNCS. This is demonstrated using an OPNET simulation model that compares a reflection based architecture with a reference architecture. The technique has applications in Smart Grid control applications (such as Fault Detection and Isolation) and in other vertical industries in which WNCSs may be relevant.

Applications of control systems on wireless networks have been widely utilized due to their mobility. However, many Wireless Networked Control Systems (WNCS) may not cooperate with each other in order to share a limited amount of network bandwidth. Consequently, these agents may manipulate the resource in their own benefit and selfish behavior. Nevertheless, existing dynamic allocation methods may not lead to equilibrium of all network-based control system satisfactions. This paper presents a decentralized auction-based dynamic bandwidth allocation methodology based on mechanism design and game theory to allocate bandwidths of WNCS which enforces WNCS on the same network to request a bandwidth with actual requirement. The proposed mechanism results has proofed an actual bandwidth requirement is the dominant strategy and the exceed bandwidth requirement cannot provide the higher utility than the actual bandwidth requirement. The total utility is the solutions of maximized social welfare.

This letter considers a wireless networked control system (WNCS), where a controller sends packets carrying control information to an actuator through a wireless channel to control a physical process for industrial-control applications. In most of the existing work on WNCSs, the packet length for transmission is fixed. However, from the channel-encoding theory, if a message is encoded into a longer codeword, its reliability is improved at the expense of longer delay. Both delay and reliability have great impact on the control performance. Such a fundamental delay-reliability tradeoff has rarely been considered in WNCSs. In this letter, we propose a novel WNCS, where the controller adaptively changes the packet length for control based on the current status of the physical process. We formulate a decision-making problem and find the optimal variable-length packet-transmission policy for minimizing the long-term average cost of the WNCSs. We derive a necessary and sufficient condition on the existence of the optimal policy in terms of the transmission reliabilities with different packet lengths and the control system parameter.

Efficiency of any service depends on several factors. The accuracy of these factors represents the actual performance of that service. In this paper, a service of such kind is implemented to evaluate an optimum value of a specific factor. Basically, in this paper, ten ambulances deployment is studied to get maximum value of area where these ambulances are used to serve. Technique used for this purpose is particle swarm optimization algorithm. To analyze this algorithm, MATLAB software is used and it has analyzed that there is an efficient increase in area coverage after implementing this algorithm.

Jamming attacks on wireless networked control systems are investigated for the scenarios where the system dynamics face exogenous disturbance. In particular, the control input packets are assumed to be transmitted from a controller to a remotely located linear plant over an insecure wireless communication channel that is subject to jamming attacks. The time-varying likelihood of transmission failures on this channel depends on the power of the jamming interference signal emitted by an attacker. We show that jamming attacks can prevent stability when the system faces disturbance, even if the attacked system without disturbance is stable. We also show that stability under jamming and disturbance can be achieved if the average jamming interference power is restricted in a certain way that we characterize in this article. We illustrate our results on an example networked control system with a fading wireless channel, where the outage probability is affected by jamming attacks.

Our research proposes an approach to finding a suitable location for a motorcycle Battery Swapping Station (BSS) that considers multiple objectives. We developed a model based on Euclidean distance with K-NN, the AHP function, a desired number of stations, and GIS-based road infrastructure data. This model also considers the maximum coverage area and satisfies the number of stations and geographical features. Additionally, we consider the average driving distance of the battery swapping station location. To facilitate analysis, square grids form cells representing road type, environmental characteristics, places, and population density. Our proposed framework provides decision-makers with a multi-objective and visually optimized motorcycle BSS location, allowing for a more flexible selection of exact BSS locations shown on a map. Our demonstration can be used to resolve the uncertain problem related to finding a place for a motorcycle battery swapping station location. to finding a place for a motorcycle battery swapping station location.

The Optimum Multiparameter (OMP) method was used to determine the relative contribution of water masses in the East China Sea (ECS) based on their measured temperature, salinity, and dissolved inorganic iodine species (DIIS, iodate and iodide) from recent oceanographic cruises in June 2014, 2015, and 2016. DIIS (as quasi‐conservative parameters) were added first into the OMP analysis, which enabled us to quantitatively estimate the water composition in the extremely dynamic and productive ECS. The OMP results indicate that seawater in the ECS mainly consisted of Changjiang Diluted Water (CDW), Taiwan Strait Warm Water (TSWW), Kuroshio Surface Water (KSW), and Kuroshio Subsurface Water (KSSW). In June 2014, 2015, and 2016, the KSSW dominated in the deep water, intruded into the ECS shelf from the northeast of Taiwan and bifurcated into a nearshore branch and offshore branch. The nearshore branch could reach north of 29°N off the Zhejiang coast. When comparing the KSSW intrusion in June 2014, 2015, and 2016, the average KSSW contribution of the bottom KSSW area in June 2016 (78.9%) was greater than in the previous 2 years (67.9% and 64.5%). In the northern transects (north of 28°N), the KSSW intrusion in June 2016 also contained the greatest average KSSW contribution and the maximum coverage area. Thus, the KSSW intrusion was strongest in June 2016 and may be comparable in June 2014 and 2015. This interannual variability of the KSSW intrusion is likely related to the El Niño‐Southern Oscillation (ENSO) rather than the Pacific Decadal Oscillation (PDO).