scholarly journals COMMUNICATION NETWORK AND QOS EVALUATION FOR FORMATION CONTROL OF UNMANNED SURFACE VEHICLES

Brodogradnja ◽  
2020 ◽  
Vol 71 (4) ◽  
pp. 19-37
Author(s):  
Shaoze Zhang ◽  
◽  
Xianbo Xiang ◽  
Shaolong Yang ◽  
◽  
...  

The main purpose of this article is to design efficient communication networks for the formation control of multiple distributed Unmanned Surface Vehicles (USVs). First, a hybrid communication network architecture, combining remote communication and wireless Ad hoc network technology is proposed. Second, an improved Low Energy Adaptive Clustering Hierarchy (LEACH) protocol is adopted to prolong the life cycle of the communication network of the USV fleet. Subsequently, some QoS indicators of the USV communication network are evaluated by establishing wireless network channel model and Signal to Interference and Noise Ratio (SINR) model. In particular, the packet error ratio, average time delay and connectivity under different formation architecture are investigated. Finally, some discussions and future work on the QoS of the USV communication network are concluded.

2020 ◽  
Author(s):  
Indushree Banerjee ◽  
Martijn Warnier ◽  
Frances M. T Brazier

Abstract When physical communication network infrastructures fail, infrastructure-less communication networks such as mobile ad-hoc networks (MANET), can provide an alternative. This, however, requires MANETs to be adaptable to dynamic contexts characterized by the changing density and mobility of devices and availability of energy sources. To address this challenge, this paper proposes a decentralized context-adaptive topology control protocol. The protocol consists of three algorithms and uses preferential attachment based on the energy availability of devices to form a loop-free scale-free adaptive topology for an ad-hoc communication network. The proposed protocol has a number of advantages. First, it is adaptive to the environment, hence applicable in scenarios where the number of participating mobile devices and their availability of energy resources is always changing. Second, it is energy-efficient through changes in the topology. This means it can be flexibly be combined with different routing protocols. Third, the protocol requires no changes on the hardware level. This means it can be implemented on all current phones, without any recalls or investments in hardware changes. The evaluation of the protocol in a simulated environment confirms the feasibility of creating and maintaining a self-adaptive ad-hoc communication network, consisting of multitudes of mobile devices for reliable communication in a dynamic context.


Sensors ◽  
2019 ◽  
Vol 19 (22) ◽  
pp. 4895
Author(s):  
Maurício R. Silva ◽  
Elitelma S. Souza ◽  
Pablo J. Alsina ◽  
Deyvid L. Leite ◽  
Mateus R. Morais ◽  
...  

This paper presents a communication network for a squadron of unmanned aerial vehicles (UAVs) to be used in the scanning rocket impact area for Barreira do Inferno Launch Center—CLBI (Rio Grande do Norte, Brazil), aiming at detecting intruder boats. The main features of communication networks associated with multi-UAV systems are presented. This system sends information through Wireless Sensor Networks (WSN). After comparing and analyzing area scanning strategies, it presents the specification of a data communication network architecture for a squadron of UAVs within a sensor network using XBee Pro 900HP S3B modules. A brief description is made about the initial information from the construction of the system. The embedded hardware and the design procedure of a dedicated communication antenna to the XBee modules are presented. In order to evaluate the performance of the proposed architecture in terms of robustness and reliability, a set of experimental tests in different communication scenarios is carried out. Network management software is employed to measure the throughput, packet loss and other performance indicators in the communication links between the different network nodes. Experimental results allow verifying the quality and performance of the network nodes, as well as the reliability of the communication links, assessing signal received quality, range and latency.


2014 ◽  
Vol 577 ◽  
pp. 835-840
Author(s):  
Yan Liu ◽  
En Guo Zhu ◽  
Xuan Liu ◽  
Li Jun Dong

To improve the performance of power consumption information collection system and to solve the problem of system capacity small and the problem of low data rate, combined with the characteristics of WiMAX technology, the 230MHz wireless communication network of Power consumption information collection system was proposed based on WiMAX; The function and working methods of the communications network was designed. Implementations applicable to power consumption information collection system's key technologies was proposed such as Time division duplex, carrier aggregation, Software-Defined Radio through experimental verification. The results show that the use of this kind of communication networks can improve the data transfer rate, meet the bandwidth requirement, improve the reliability of data transmission and system Capacity and meet the business requirements of power consumption information collection system.


The mobile communication networks and towers go down or cease to exist leading to poor connectivity during disasters. When communication becomes paralyzed, it is vital to build a disaster relief solution with available resources. Without data connectivity, it is essential that an emergency protocol should be implemented by the government that uses the available paralyzed communication resources spread across various communication networks by pooling to form one single communication network backed by cloud facilities to restore connectivity. In this paper the authors introduce a new emergency protocol approach to design an unrestricted cloud-based mobile technology during disaster enabling instant communication services to the disaster zones that works best under the command of the government. This protocol can act faster than the existing communication network put in place for public communication, with the additional advantage of being more robust and capable of withstanding disaster conditions


2020 ◽  
Author(s):  
Indushree Banerjee ◽  
Martijn Warnier ◽  
Frances M. T Brazier

Abstract When physical communication network infrastructures fail, infrastructure-less communication networks such as mobile ad-hoc networks (MANET), can provide an alternative. This, however, requires MANETs to be adaptable to dynamic contexts characterized by the changing density and mobility of devices and availability of energy sources. To address this challenge, this paper proposes a decentralized context-adaptive topology control protocol. The protocol consists of three algorithms and uses preferential attachment based on the energy availability of devices to form a loop-free scale-free adaptive topology for an ad-hoc communication network. The proposed protocol has a number of advantages. First, it is adaptive to the environment, hence applicable in scenarios where the number of participating mobile devices and their availability of energy resources is always changing. Second, it is energy-efficient through changes in the topology. This means it can be flexibly be combined with different routing protocols. Third, the protocol requires no changes on the hardware level. This means it can be implemented on all current phones, without any recalls or investments in hardware changes. The evaluation of the protocol in a simulated environment confirms the feasibility of creating and maintaining a self-adaptive ad-hoc communication network, consisting of multitudes of mobile devices for reliable communication in a dynamic context.


2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Andrea Duggento ◽  
Marco Aiello ◽  
Carlo Cavaliere ◽  
Giuseppe L. Cascella ◽  
Davide Cascella ◽  
...  

Breast cancer is one of the most common cancers in women, with more than 1,300,000 cases and 450,000 deaths each year worldwide. In this context, recent studies showed that early breast cancer detection, along with suitable treatment, could significantly reduce breast cancer death rates in the long term. X-ray mammography is still the instrument of choice in breast cancer screening. In this context, the false-positive and false-negative rates commonly achieved by radiologists are extremely arduous to estimate and control although some authors have estimated figures of up to 20% of total diagnoses or more. The introduction of novel artificial intelligence (AI) technologies applied to the diagnosis and, possibly, prognosis of breast cancer could revolutionize the current status of the management of the breast cancer patient by assisting the radiologist in clinical image interpretation. Lately, a breakthrough in the AI field has been brought about by the introduction of deep learning techniques in general and of convolutional neural networks in particular. Such techniques require no a priori feature space definition from the operator and are able to achieve classification performances which can even surpass human experts. In this paper, we design and validate an ad hoc CNN architecture specialized in breast lesion classification from imaging data only. We explore a total of 260 model architectures in a train-validation-test split in order to propose a model selection criterion which can pose the emphasis on reducing false negatives while still retaining acceptable accuracy. We achieve an area under the receiver operatic characteristics curve of 0.785 (accuracy 71.19%) on the test set, demonstrating how an ad hoc random initialization architecture can and should be fine tuned to a specific problem, especially in biomedical applications.


2021 ◽  
Vol 11 (2) ◽  
pp. 546
Author(s):  
Jiajia Xie ◽  
Rui Zhou ◽  
Yuan Liu ◽  
Jun Luo ◽  
Shaorong Xie ◽  
...  

The high performance and efficiency of multiple unmanned surface vehicles (multi-USV) promote the further civilian and military applications of coordinated USV. As the basis of multiple USVs’ cooperative work, considerable attention has been spent on developing the decentralized formation control of the USV swarm. Formation control of multiple USV belongs to the geometric problems of a multi-robot system. The main challenge is the way to generate and maintain the formation of a multi-robot system. The rapid development of reinforcement learning provides us with a new solution to deal with these problems. In this paper, we introduce a decentralized structure of the multi-USV system and employ reinforcement learning to deal with the formation control of a multi-USV system in a leader–follower topology. Therefore, we propose an asynchronous decentralized formation control scheme based on reinforcement learning for multiple USVs. First, a simplified USV model is established. Simultaneously, the formation shape model is built to provide formation parameters and to describe the physical relationship between USVs. Second, the advantage deep deterministic policy gradient algorithm (ADDPG) is proposed. Third, formation generation policies and formation maintenance policies based on the ADDPG are proposed to form and maintain the given geometry structure of the team of USVs during movement. Moreover, three new reward functions are designed and utilized to promote policy learning. Finally, various experiments are conducted to validate the performance of the proposed formation control scheme. Simulation results and contrast experiments demonstrate the efficiency and stability of the formation control scheme.


2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Xibin Zhao ◽  
Zhiyang You ◽  
Hai Wan

Mobile ad hoc network (MANET) is a dynamic wireless communication network. Because of the dynamic and infrastructureless characteristics, MANET is vulnerable in reliability. This paper presents a novel reliability analysis for MANET. The node mobility effect and the node reliability based on a real MANET platform are modeled and analyzed. An effective Monte Carlo method for reliability analysis is proposed. A detailed evaluation is performed in terms of the experiment results.


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