阅读说明：本技术 一种面向动态水下环境的锚节点部署方法 (Anchor node deployment method for dynamic underwater environment ) 是由 刘春凤 邱铁 赵昭 曲雯毓 于 2019-08-02 设计创作，主要内容包括：本发明公开一种面向动态水下环境的锚节点部署方法,包括如下步骤：步骤1、随机部署水下节点并根据其位置划分普通节点和边缘节点建立锚节点模型；设N＝0；步骤2,对锚节点模型中每个节点进行广播自身相关信息同时接收和存储其他节点信息；步骤3,计算每个节点自身所受虚拟力的合力；步骤4,计算每个普通节点和边界节点预期移动距离；步骤5,根据节点的类型计算移动收益；步骤6,计算每个节点沿锚链移动距离；步骤7,判断每个节点是否满足N≥45,如果满足,则退出程序；否则返回步骤1,令N＝N+1；本发明提供了综合考虑节点密度、节点剩余能量和节点移动效果的移动效益函数,以此降低节点不必要的移动,并均衡节点剩余能量,达到降低和均衡能耗的目的。(The invention discloses an anchor node deployment method facing a dynamic underwater environment, which comprises the following steps: step 1, deploying underwater nodes randomly, and dividing common nodes and edge nodes according to the positions of the underwater nodes to establish an anchor node model; setting N as 0; step 2, broadcasting self-related information to each node in the anchor node model and simultaneously receiving and storing information of other nodes; step 3, calculating the resultant force of the virtual force borne by each node; step 4, calculating the expected moving distance of each common node and each boundary node; step 5, calculating the mobile profit according to the type of the node; step 6, calculating the moving distance of each node along the anchor chain; step 7, judging whether each node meets N not less than 45, and if so, exiting the program; otherwise, returning to the step 1, and enabling N to be N + 1; the invention provides a movement benefit function which comprehensively considers the node density, the node residual energy and the node movement effect, thereby reducing the unnecessary movement of the node, balancing the node residual energy and achieving the purpose of reducing and balancing the energy consumption.)

1. an anchor node deployment method facing a dynamic underwater environment is characterized by comprising the following steps:

Step 1, deploying underwater nodes randomly, and dividing common nodes and edge nodes according to the positions of the underwater nodes to establish an anchor node model; setting N as 0;

Step 2, broadcasting self-related information to each node in the anchor node model and simultaneously receiving and storing information of other nodes;

Step 3, calculating the resultant force of the virtual force borne by each node through the following formula;

step 4, calculating the expected moving distance by each common node and each boundary node according to the following formula;

Step 5, calculating the mobile profit according to the type of the node through the following formula;

Step 6, calculating the moving distance of each node along the anchor chain by the following formula;

Step 7, judging whether each node meets N not less than 45, and if so, exiting the program; otherwise, returning to the step 1, and making N equal to N + 1.

2. The anchor node deployment method oriented to the dynamic underwater environment as claimed in claim 1, wherein in the step 3, each node calculates the virtual force between the node and the neighbor node through the following formula

3. The anchor node deployment method for the dynamic underwater environment as claimed in claim 1, wherein each node in the step 3 calculates the virtual force between the node and the upper and lower boundaries by the following formula

Technical Field

the invention relates to the technical field of underwater wireless sensor networks, in particular to an anchor node deployment method for a dynamic underwater environment.

background

The underwater wireless sensor network is used as a convenient tool for knowing and knowing the ocean, so that people can obtain more ocean information, the monitoring and predicting capability on the ocean environment is improved, and people are helped to deal with ocean emergencies and the like. The method is widely applied to marine information acquisition, environment monitoring, deep sea detection, disaster prediction, auxiliary navigation, distributed tactical monitoring and the like. The application is based on the premise that the relevant sea area is effectively monitored in the environment, and the relevant sea area is effectively covered by the underwater wireless sensor network node. Therefore, the node deployment strategy of the underwater sensor network needs to increase research on improving node deployment in a dynamic water area on the basis of previous research work.

during deployment of the nodes of the underwater wireless sensor network, the nodes are usually randomly thrown to the surface of the ocean and then sink to a certain depth through a certain calculation, so that an underwater monitoring area is covered. Anchor nodes with anchor chains are widely used, the anchors of which are sunk to the water bottom, the nodes are fixed by the anchor chains connected with the anchors and suspended in the water, and the anchor nodes can move along the anchor chains to adjust the positions of the anchor nodes and complete the deployment of the network nodes. In the process, waves and ocean currents can affect the sinking process of the nodes, the nodes cannot reach the designated positions, and the network coverage effect is poor. Meanwhile, in the network operation process, the nodes of the UWSNs move and shift under the influence of ocean currents, so that the network coverage rate is reduced. Furthermore, the sensor nodes are powered by batteries. In a submarine environment, the energy of the nodes is limited and difficult to charge. In the node deployment process, the energy consumption of node movement is much larger than that of node communication, and the node energy consumption in the deployment process needs to be further reduced and balanced while the network coverage effect is ensured, so that the network operation time is increased. However, as far as we know, the existing underwater sensor network deployment strategy is to fully consider the influence of water flow movement on the node deployment effect and the influence of node movement and offset on network coverage during the network operation process. For example, the journal "a Sensor recovery Algorithm Based on Virtual force for underwater Sensor Networks" proposes a Virtual force-Based underwater wireless Sensor network node deployment strategy, but the adopted nodes are not limited by anchor chains, and in the network operation process, water flow can cause node deviation, so that long-time effective monitoring on related water areas cannot be performed. In an underwater wireless sensor network consisting of anchor nodes, the underwater environment needs to be specifically analyzed by utilizing a virtual force strategy to carry out node deployment, and a node deployment flow is redesigned.

Disclosure of Invention

The invention provides a distributed underwater wireless sensor network anchor node deployment strategy based on virtual force, aiming at the problem of low network coverage rate of a monitoring area caused by water flow of a dynamic water area. The network coverage rate is effectively improved, and meanwhile, the energy consumption in the deployment process is reduced and balanced.

In order to solve the technical problem, the invention provides a virtual force underwater anchor node deployment strategy. According to the invention, the nodes are classified according to the distance relationship between the coordinates after node deviation and the monitoring area boundary, so that unnecessary node movement is reduced and the deployment energy consumption is reduced while the nodes are prevented from escaping from the monitoring area; the invention designs a movement benefit function which comprehensively considers the node density, the node residual energy and the node movement effect, thereby reducing the unnecessary movement of the node, balancing the node residual energy and achieving the purpose of reducing and balancing the energy consumption.

The purpose of the invention is realized by the following technical scheme: an underwater anchor node deployment method based on virtual force comprises the following steps:

An anchor node deployment method facing a dynamic underwater environment comprises the following steps:

Step 1, deploying underwater nodes randomly, and dividing common nodes and edge nodes according to the positions of the underwater nodes to establish an anchor node model; setting N as 0;

Step 2, broadcasting self-related information to each node in the anchor node model and simultaneously receiving and storing information of other nodes;

Step 3, calculating the resultant force of the virtual force borne by each node through the following formula;

Step 4, calculating the expected moving distance by each common node and each boundary node according to the following formula;

Step 5, calculating the mobile profit according to the type of the node through the following formula;

Step 6, calculating the moving distance of each node along the anchor chain by the following formula;

step 7, judging whether each node meets N not less than 45, and if so, exiting the program; otherwise, returning to the step 1, and making N equal to N + 1.

In the step 3, each node calculates the virtual force between the node and the adjacent node through the following formula, namely

In the step 3, each node calculates the virtual force between the node and the upper and lower boundaries through the following formula, namely

Advantageous effects

1. the invention designs an anchor node deployment strategy suitable for a dynamic underwater environment by utilizing a virtual force theory, and can improve the network coverage rate in a distributed manner.

2. The invention reduces and balances the node moving distance by utilizing the moving benefit function which comprehensively considers the node density, the node residual energy and the node moving effect, thereby achieving the effect of reducing and balancing the node energy consumption.

3. The invention aims to design an anchor node deployment method facing a dynamic underwater environment, which improves the coverage rate of an underwater wireless sensor network in a dynamic water area; energy consumption in the anchor node deployment process is reduced and balanced, and network operation time is prolonged.

drawings

FIG. 1 is a flow diagram of a node deployment strategy;

FIG. 2 is a graph of anchor node deviation from a static position;

Detailed Description

The following detailed description of the specific modes, structures, features and functions of the node deployment strategy designed according to the present invention is provided with the accompanying drawings.

the invention provides an anchor node deployment method facing a dynamic underwater environment, which comprises the following steps:

As shown in fig. 1; step 1: the nodes are randomly deployed to the water surface of the monitoring area and randomly sink to the upper half of the monitoring area. And each node calculates the coordinate of the node according to the position, the water depth, the water flow size and the water flow direction of the submarine anchor, and judges the distance from the node to the boundary of the surrounding monitoring area without including an upper boundary and a lower boundary. If the distance between the two is less than the optimal boundary distance d_obthen dividing the self into boundary nodes; otherwise, the nodes are divided into common nodes. Meanwhile, let N be 0;

Wherein the optimal boundary distance d_obIs 0.5 times the perceived radius of the node.

Step 2: all nodes in the network broadcast own node ID, coordinates, residual energy, water flow size and water flow direction in the maximum node communication radius, and simultaneously receive and store the related information of other nodes.

and step 3: each node calculates the virtual force between itself and the adjacent node according to the stress formula of the anchor chain direction of the nodeAnd calculating the virtual force between the node and the upper and lower boundaries according to the force formula between the node and the upper and lower boundariesFinally, the resultant force borne by the node is calculated according to a resultant force formula

wherein, the formula of the stress in the direction of the anchor chain of the node i is specifically the formula (1)

In the formula, tau represents the included angle between a unit vector in the direction from the node i to the node j and a unit vector in the direction from the node i to the water bottom;represents the force applied by the node j to the node i, and is obtained by the following formula (2)

In the formula d_ijRepresenting the Euclidean distance between the node i and the node j; k is a radical of_rAnd k_aRespectively a repulsion force adjusting coefficient and an attraction force adjusting coefficient; d_thRepresenting an inter-node stress threshold; r_c(i) indicating the communication radius of node i.

wherein, the formula of the stress between the node and the surrounding boundary is specifically the formula (3)

in the formula d_ibrRepresenting the distance from the node i to the upper and lower boundaries; d_obRepresenting an optimal boundary distance; k is a radical of_bRepresenting a boundary force adjustment coefficient; α represents the vertical offset angle of node i affected by the water flow.

Wherein the resultant force formula is specifically formula (4)

Wherein N (i) represents the number of nodes within the communication radius of the node i;representing stress between nodes;Representing the force between the node and the surrounding boundary.

And 4, step 4: each common node and the boundary node in the downward stress direction calculate the distance of the node to move along the anchor chain through a predicted movement distance function; then calculating the self mobile benefit omega through a mobile benefit function, wherein the mobile benefit of the boundary node with the upward stress direction is 0; and finally, each node calculates the moving distance of the node along the anchor chain according to the actual moving distance function and moves.

wherein the function of the expected moving distance is specifically represented by formula (5)

in the formula I_maxrepresenting the maximum distance of the single step movement of the node;Representing the resultant force of the node.

step 5, the node movement benefit function is specifically the formula (6)

In the formula, the value range of the lambda mobile benefit adjusting coefficient is [0,1 ]]；θ_w1A water flow horizontal offset angle representing a depth at which the node is located before movement; theta_w2The horizontal deviation angle of the water flow representing the depth of the node after moving is obtained through the expected distance function; theta_fRepresenting the horizontal deviation angle of the node subjected to the resultant force of other neighbor nodes; omega_peExpressed as node density-energy weight, calculated by the following formula (7)

In the formula, a and b respectively represent a node density adjusting coefficient and a node energy adjusting coefficient; p is a radical of_band p_sRespectively representing the number of neighbor nodes in a node moving direction area and the number of neighbor nodes in a node reverse moving direction area;Representing the average value of the residual energy of the node and the neighbor nodes; e_rRepresenting the node residual energy.

step 6, the actual moving distance function is specifically the formula (8)

wherein omega represents the node moving benefit; l_maxRepresenting the maximum distance of the single step movement of the node;Representing the resultant force of the node.

And 7: repeating steps 1, 2, 3 and 4 periodically; until the maximum iteration time, the iteration time is 45 times, namely N is more than or equal to 45. In the process, the maximum jitter number is set to 5, and when the repeated up-and-down times of a node is greater than the maximum jitter number, the node is set to reach the stress equilibrium state, and the node does not move any more.

It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.