Current Issue : October - December Volume : 2020 Issue Number : 4 Articles : 5 Articles
This paper proposes a consensus-based guidance methodology for multiple air vehicles to arrive at the same spot cooperatively.\nFirst, based on the Lyapunov stability theory, a guidance law with only one control parameter is proposed, and the exact\nexpression of total flight time can be obtained with a control parameter equal to one. Then, a two-step guidance scheme, which can\nachieve a finite-time consensus of the flight time, is built upon the Lyapunov-based guidance law. In the first step, on account of\nthe information exchange between the air vehicles through an undirected and connected communication topology, a time-varying\ncontrol parameter is designed to reduce the disparities of the flight time. After the consensus of the flight time, the control\nparameter will remain constant at one, and simultaneous arrival can be achieved. Besides, the guidance strategy is applied in a\nleader-follower case that one of the vehicles cannot receive information from the others and acts as the leader. The effectiveness of\nthe proposed method is demonstrated with simulations....
Wireless power transfer techniques to transfer energy have been widely adopted by wireless rechargeable sensor networks\n(WRSNs). These techniques are aimed at increasing network lifetime by transferring power to end devices. Under these wireless\ntechniques, the incurred charging latency to replenish the sensor nodes is considered as one of the major issues in wireless\nsensor networks (WSNs). Existing recharging schemes rely on rigid recharging schedules to recharge a WSN deployment using\na single global charger. Although these schemes charge devices, they are not on-demand and incur higher charging latency\naffecting the lifetime of a WSN. This paper proposes a collaborative recharging technique to offload recharging workload to\nlocal chargers. Experiment results reveal that the proposed scheme maximizes average network lifetime and has better average\ncharging throughput and charging latency compared to a global charger-based recharging....
As node energy of wireless sensor networks (WSN) is limited and cannot be supplemented after exhaustion, clustering algorithm\nis frequently taken as an effective method to prolong the lifetime of WSN. However, the existing clustering algorithms have some\ndrawbacks, either consuming excessive energy as a result of exchanging too much controlling information between nodes, or\nlacking a comprehensive perspective in terms of the balance among several conflicting objectives. In order to overcome these\nshortcomings, a novel combinatorial optimization-based clustering algorithm (COCA) for WSN is proposed in this paper.\nDifferent from the above mentioned algorithms which take clustering as a continuous optimization problem, COCA solves the\nclustering problem from the perspective of combinatorial optimization. Firstly, the clustering of WSN is abstracted into a\ncombinatorial optimization problem. Then, the binary particle coding scheme of cluster head is proposed, which is based on the\ncorresponding relationship between nodes and particle position vectors, and the fitness function is designed according to the\nparameters used in the process of cluster formation. Finally, the binary particle swarm optimization algorithm is applied to\nimplement the clustering. COCA is validated under different scenarios compared with three other clustering algorithms. The\nsimulation results show that COCA has better performance than its comparable algorithms....
Aiming at the transmission of heterogeneous data in heterogeneous networks, a topology optimization algorithm of heterogeneous\nwireless sensor networks based on local tree reconstruction is proposed, which can achieve better data transmission in the\nheterogeneous networks. First, the algorithm divides the nodes of the network into different layers by their hops and chooses\ndifferent numbers of nodes as relay nodes in different layers. Second, the nodes are set with different initial energies in different\nlayers. Because the packets of different nodes have different sizes, we adopt the corresponding data aggregation coefficients\naccording to the actual data requirements of the network in data transmission. Finally, the lifetime of the network is prolonged by\nreal-time updating of the topology of the tree during the data transmission. The simulations indicate that after the aforementioned\nthree steps, the proposed algorithm prolongs the lifetime of the heterogeneous networks and improves the nodes\nutilization effectively....
Source localization is one of the major research contents in the localization research of wireless sensor networks, which has\nattracted considerable attention for a long period. In recent years, the wireless binary sensor network (WBSN) has been widely\nused for source localization due to its high energy efficiency. A novel method which is based on WBSN for multiple source\nlocalization is presented in this paper. Firstly, the Neyman-Pearson criterion-based sensing model which takes into account the\nfalse alarms is utilized to identify the alarmed nodes. Secondly, the mean shift and hierarchical clustering method are performed\non the alarmed nodes to obtain the cluster centers as the initial locations of signal sources. Finally, some voting matrices which\ncan improve the localization accuracy are constructed to decide the location of each acoustic source. The simulation results\ndemonstrate that the proposed method can provide a desirable performance superior to some traditional methods in accuracy\nand efficiency....
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