CN103139862A - Wireless sensor network multi-source data fusion method based on queries - Google Patents

Abstract

The invention relates to a wireless sensor network multi-source data fusion method based on queries. The wireless sensor network multi-source data fusion method based on the queries comprises clustering, interest spreading and data transmission. In the clustering process, node residual energy to cluster, density of a node placed area and the distance from cluster heads to a base station are utilized. In the interest spreading process, a sink node firstly spread interest news to all cluster heads which then determine whether interest is spread inside clusters according to actual conditions. In the data transmission process, a neighbor node large in priority is chosen as a next jumping node. A priority function enables query data to be transmitted to the sink node along the route which is small in energy consumption, large in residual energy and short in distance according to introducing of neighbor node positions, the fact that whether introduced nodes are source nodes or the cluster heads, residual energy, communication cost of two nodes and the like, and data fusion is performed on the data intersecting position. The wireless sensor network multi-source data fusion method based on the queries can effectively balance node energy consumption in networks, improve energy using efficiency and prolong a network life cycle.

Description

Wireless sensor network multi-source data fusion method based on inquiry

Technical field

The invention belongs to the wireless sensor network technology field, relate to a kind of based on inquiry the wireless sensor network multi-source data fusion method.

Background technology

Wireless sensor network (Wireless Sensor Network, WSN) be a kind of novel data-centered wireless network, it has merged sensor technology, wireless communication technology and database processing technology, is comprised of the node with sensing, calculating and communication capacity.Major function is the information of monitored area, collecting sensor node place, carries out passing to the sink node after certain processing, realizes the monitoring to physical world.All be widely used in many fields such as military affairs, industry, agricultural, environment, medical monitoring, intelligentized Furniture systems.

Routing Protocol is responsible for packet from source node by forwarded to destination node, and it mainly comprises the function of two aspects: seek the path optimizing between source node and destination node, packet is correctly forwarded along path optimizing.But, due to WSN from process in energy supply, data and communication capacity on restriction, its Routing Protocol and traditional Routing Protocol have larger different, effective utilization of energy is the important goal of WSN Design of Routing Protocol.

Wireless sensor network is take monitored area and perception data as purpose, and data flow to the sink node from sensor node.Data-centered formation data forwarding paths is a kind of routing mechanism of suitable wireless sensor network, namely is based on this mechanism based on the Routing Protocol of inquiring about.The data query agreement is one of key issue in sensor network, goes back at present the unified data query agreement of neither one and can adapt to all sensor networks, for different application, designs the network system that is fit to this application and could deal with problems efficiently.After the Sink node sends query messages, the method that adopts each node to transfer data to separately aggregation node in the process of the information of collection is inappropriate, main cause has waste communication bandwidth and energy, reduce the efficient of information, a plurality of nodes transmit the scheduling difficulty that data can increase data link layer simultaneously, cause conflict collision frequently, reduced communication efficiency, thereby affected the promptness of information.In sensor network, (node is according to the content of data to transfer to data-centric routing from traditional route centered by the address (node is along the shortest path forwarding data to the sink node) with research focus to consider the routing mode of data fusion, data from a plurality of data sources are carried out mixing operation, then forwarding data).Therefore, wireless sensor network needs the route designing low complex degree, high data fusion rate, low energy consumption and be convenient to safeguard in collecting data procedures.

The data query Routing Protocol is most typical is directed diffusion (Directed Diffusion, DD), and the routing mechanism of directed diffusion can be divided into three phases: interest diffusion, gradient foundation and data are along strengthening path transmission, as shown in Figure 1.Wherein, interest diffusion and detection gradient are set up the plane that all depends on information and are flooded, and time and energy expense are all larger, and can produce bulk redundancy information, have had a strong impact on the energy utilization efficiency of directed diffusion.More seriously, along with the increase of wireless sensor network scale, the expense that floods can rapidly improve, and makes directed diffusion be difficult to be applied in large scale network.Current improvement research for Directed Diffusion Algorithm concentrates on range of scatter or data dissemination scope how to control interest message, thereby reduces the consumption of nodes energy.

(1) in the interest diffusion stage, by set up bunch or tree structure with network hierarchy, reduce the jumping figure that interest message or detection data are forwarded.Or limit the degree of depth of source node and the diffusion of each forward node and the forwarding scope that range reduces interest message by the threshold value of definition gradient.Reach energy efficient, shorten network delay, extend the purpose of network lifecycle.

(2) at the gradient establishment stage, source node sends in the process of probe data packet to the sink node, and the mode that floods produces a large amount of redundant informations when bringing huge network energy consumption and network delay.Reducing or remove the energy consumption that the transmission probe data packet is brought, is to improve the network energy utilance, reduce the approach of wanting in of network delay.

(3) after strengthening the path and forming, source node sends to the sink node with image data along the path of strengthening.When polling cycle was longer, the node on this path can because of the excessive and too early death of energy consumption, cause network to cut apart.Shorter when polling cycle, when interest message frequently changes, if all will sending probe data packet foundation, each source node strengthens the path, to a certain degree there is very large energy dissipation.According to the dump energy of neighbor node, whether be that bunch head or the factors such as source node, position are selected next-hop node, effectively the energy consumption of each node in equalizing network, extend network lifecycle.

Summary of the invention

The objective of the invention is to overcome in existing data query Routing Protocol the large and node energy consumption inequality problem of energy consumption, a kind of wireless sensor network multi-source data fusion method based on inquiry is provided, at first solve by sub-clustering the huge energy consumption that the interest diffusion stage mode of flooding is brought, then set up and the path reinforcement stage by omitting gradient, reduce and set up energy consumption and the network delay problem that gradient and path reinforcement bring, thereby effectively extend network lifecycle.

According to technical scheme provided by the invention, the wireless sensor network multi-source data fusion method based on inquiry comprises network cluster dividing, interest diffusion and transfer of data three phases, and is specific as follows.

(1) network cluster dividing.

1) in the election of cluster head stage, utilize the sparse degree of the dump energy of node and node region to guarantee the even distribution of bunch head; Be that at first each node chooses a random number between [0,1], with threshold value T (v _i) compare, if this number is less than threshold value T (v _i), this node is elected as a bunch head, wherein threshold value T (v _i) adopting formula (1), formula (2) is adopted in the density calculation of node region.

2) bunch establishment stage, in conjunction with the node density of each bunch region with construct apart from the distance of sink node bunch radius cluster that differs in size; Reach each bunch of balance offered load, the purpose of equalizing network energy consumption.The structure of bunch radius adopts formula (3).

3) bunch head is set up bunch information about firms table, the ID of record bunch member node, dump energy, node coordinate, data acquisition type etc.

(2) interest diffusion.

1) the sink node periodically sends to all bunch heads by the mode of single-hop or multi-hop with interest message.Interest message is the specific descriptions to acquisition tasks, comprising: the parameters such as task type, target area, data transmission rate.

2) after a bunch head is received interest message, the own bunch member node information table of keeping of inquiry at first, if bunch in exist node to gather the requirement of data fit interest, in this bunch head is diffused into interest message bunch, if not indiffusion.

(3) transfer of data.

After network topology structure was stable, the sink node was diffused into interest message in network for carrying out data query, and the node of the data fit sink node interest of collection becomes source node.After node has data to produce or receives data, according to the energy of neighbor node, have or not data, determine shift direction apart from path energy consumption etc., use routing table table _k(k=1,2 ... m) record source node with data be sent to the sink node the node of process.Each source node calculates the priority of all neighbor nodes, select priority high as next-hop node, until send data to the sink node.In addition, can better carry out data fusion for guaranteeing data in transmitting procedure, make the priority of source node and bunch head individual higher than other ordinary node, avoid not having the node of data to waste energy as the via node forwarding data.Wherein pri function adopts formula (4)-(13).

Advantage of the present invention is:

(1) with network hierarchy, carry out interest diffusion.At first the present invention is divided into a multitiered network by sub-clustering with network.Then, the sink node arrives each bunch head by the mode of single-hop or multi-hop with interest diffusion.At last, bunch head again according to bunch in member's information whether determine with interest diffusion to bunch in.Than the mode that floods, the present invention can effectively reduce the energy consumption in interest diffusion stage.In addition, cause the problem of energy consumption inequality in network for even cluster algorithm in the past, adopt the thought of Uneven Cluster, utilize node density and dump energy that the selection threshold value of bunch head is set, in a node compact district increase bunch quantity, bunch an establishment stage utilization bunch density and set up different bunch radiuses apart from the distance of sink node, reach the purpose of balance the whole network bunch scale.

(2) omitting gradient sets up and the path reinforcement stage.At the gradient establishment stage, source node sends in the process of probe data packet to the sink node, and the mode that floods produces a large amount of redundant informations when bringing huge network energy consumption and network delay.Reducing or remove the energy consumption that the transmission probe data packet is brought, is an important approach that improves the network energy utilance, reduces network delay.After the reinforcement path formed, source node sent to the sink node with image data along the path of strengthening.When polling cycle was longer, the node on this path can because of the excessive and too early death of energy consumption, cause network to cut apart.Do not set up in advance the path, directly from neighbor node according to the dump energy of node, whether be that the factors such as source node, position are selected next-hop node, effectively the energy consumption of each node in equalizing network, extend network lifecycle.

(3) the present invention proposes a kind of novel neighbor node selection strategy, namely constructs pri function according to the communication cost between the type of the dump energy of neighbor node, node, position, two nodes.Avoid the low node of energy to add data transfer path, realize the harmony of nodes energy consumption.Increase the priority of bunch head and source node, reduce ordinary node just as via node and forwarding data and the energy dissipation that causes.The priority of the neighbor node near apart from the sink node is higher, guarantees that data are towards the direction transmission of sink node.Select the low path of communication cost between two nodes, conserve energy, improve energy-efficiency better.

Description of drawings

Fig. 1 is directed diffusion Route establishment process.

Fig. 2 node location and Route Selection.

Fig. 3 is nodes distribution situation and node type.

Fig. 4 is the graph of a relation of the operation wheel number of data packet transmission amount and network in network.

Fig. 5 is that in network, every energy of taking turns consumes comparison diagram.

Fig. 6 is dump energy comparison diagram in network.

Fig. 7 is the life cycle comparison diagram of network.Fig. 7 (a) is the network lifecycle comparison diagram of 100 o'clock for the nodes number.Fig. 7 (b) is the network lifecycle comparison diagram of 200 o'clock for the nodes number.

Embodiment

Wireless sensor network multi-source data fusion method based on inquiry comprises sub-clustering, interest diffusion and transfer of data three phases, and wherein, the present invention periodically carries out, and enters resting state when node is not worked.The physical model that the present invention relates to is: in the zone of 200m * 200m, and 100 nodes of random arrangement, wherein the sink node is positioned at (100,200).The physical model that adopts is:

(1) all nodes have identical primary power, have the function of data fusion;

(2) all nodes can communicate with the sink node;

(3) radio signal energy on all directions consumes identical;

(4) the sink node is fixed, Infinite Energy system.

At first the present invention is divided into a Hierarchical network by sub-clustering with network, namely by probability, the energy of node and the isoparametric selection that sets up the cluster head of neighbor node number of node to the elected bunch head of nodes, and utilize the density of node and distance parameter to build bunch; Then, the mode of sink node by single-hop or multi-hop with interest diffusion to each bunch head, bunch head again according to bunch in member's information whether determine with interest diffusion to bunch in, seek accordingly the collection that suitable source node is used for data; At last, the data-transmission mode of selecting next-hop node to set up multi-hop according to the priority of neighbor node is used for sending data to the sink node.The present invention is described in detail from network cluster dividing, interest diffusion and transfer of data three aspects for the below.

1 network cluster dividing

The present invention is in the selection course of bunch head, and the isoparametric setting of density by to the energy of the probability of the elected bunch head of nodes, node and node region guarantees the even distribution of bunch head in network.Bunch establishment stage according to the node density of a bunch region with construct apart from the distance of sink node bunch radius cluster that differs in size; Reach each bunch of balance offered load, the purpose of equalizing network energy consumption.Detailed process is as follows:

At first carry out the selection of bunch head, at first each node chooses a random number between [0,1], with threshold value T (v _i) compare, if this number is less than threshold value T (v _i), node is elected as a bunch head.T (v wherein _i) computational methods adopt (1) formula, (2) formula is adopted in the density calculation of node region, computational methods are as follows:

$T\left(v_i\right)=\left\{\begin{array}{cc}\frac{p}{1-p(r*\mathrm{mod}\frac{1}{p})}\frac{E_{i\_\mathrm{residual}}}{E_0}(1+{\mathrm{\&alpha;}}_i),& v_i\&Element;\mathrm{<figure-callout\; id="0"\; label="G"\; filenames="DEST\_PATH\_HSB00001026256300022.png,DEST\_PATH\_HSB00001026256300032.png"\; state="\{\{state\}\}">G</figure-callout>}\\ 0,& v_i\&NotElement;G\end{array}\right..---\left(1\right)$

${\mathrm{\&alpha;}}_i=\frac{\mathrm{Neighbor}\left(v_i\right)\_\mathrm{alive}-\frac{1}{p}}{\mathrm{Network}\_\mathrm{alive}}.---\left(2\right)$

Wherein, p is the probability of the elected bunch head of node; R is the wheel number that loops at present; G also was not elected to the node set of bunch head in nearest 1/p wheel; α _iExpression node v _iDensity, Neighbor (v _i) _ alive and Network_alive represent respectively node v _iNeighbor node and whole network in the number of survival node, namely dump energy is greater than 0 number.E ₀And E _{I_residual}The primary power and the dump energy that represent respectively node.

After bunch head was selected, non-leader cluster node entered sleep state, sink node signal of broadcasting in the network, and each bunch head calculates it to the approximate distance of sink node according to the intensity that receives signal

And definite its bunch radius R _Hi, the maximum bunch radius of order bunch head is R ₀, the radius calculation formula of bunch head is as follows:

$R_{\mathrm{Hi}}=\left[(1-{\mathrm{\&alpha;}}_{\mathrm{Hi}})\frac{d_{\max }-d_{\mathrm{Hi}\_\sin k}}{d_{\max }-d_{\min }}\right]{\mathrm{<figure-callout\; id="0"\; label="R"\; filenames="DEST\_PATH\_HSB00001026256300022.png,DEST\_PATH\_HSB00001026256300032.png"\; state="\{\{state\}\}">R</figure-callout>}}_0.---\left(3\right)$

Wherein, α _HiBe a bunch H _iDensity, value between 0～1, d _maxAnd d _minRepresent that respectively bunch head in network is to the minimum and maximum distance of sink node, d _{Hi_sink}An expression bunch H _iDistance with the sink node.

The radius of each bunch is in dormant node and is waken up after establishing, and each bunch head is broadcasted its bunch radius R separately _Hi, non-leader cluster node is according to R _HiAnd d (v _i, H _i) select a bunch head, selection course is as follows:

Step 1: node is selected and an own nearest bunch H _i

Step 2: computing node and a bunch H _iApart from d (v _i, H _i), and compare d (v _i, H _i) and bunch radius R _HiSize, if d (v _i, H _i)≤R _HiAdd this bunch.If d is (v _i, H _i)＞R _HiReturn to step 1.

Step 3: if with the nearer bunch H of node _iDo not exist, perhaps do not exist to meet d (v _i, H _i)≤R _HiBunch head, node add nearest neighbor node place bunch, thereby become a bunch member node.

After data arrived each bunch head, bunch head was according to the information d (H that obtains at bunch establishment stage _i, H _j) and d _{Hj_sink}Selection is from own nearest bunch head, in the mode of multi-hop, final fused data is sent to the sink node.

After network cluster dividing was completed, leader cluster node was set up bunch information about firms table, for information such as the ID that records bunch member node, dump energy, node coordinate, data acquisition types.

2 interest diffusions.

1) after network cluster dividing is completed, carry out the diffusion of interest.The sink node sends to all bunch heads by the mode of single-hop or multi-hop with interest message.Interest message is the specific descriptions to acquisition tasks, comprising: the parameters such as task type, target area, data transmission rate.

2) after a bunch head is received interest message, the own bunch member node information table of keeping of inquiry, if bunch in exist node to gather the requirement of data fit interest, in this bunch head is diffused into interest message bunch, and will to meet the Node configuration that interest requires be source node, if not indiffusion.

3 transfer of data.

When the sink node is diffused into network for carrying out data query with interest message, and after finding source node, each source node calculates the priority of all neighbor nodes, selects the high neighbor node of priority as next-hop node; Namely have data to produce or receive the node of data according to the energy of neighbor node, select the node of down hop apart from path energy consumption etc., the transmission direction of specified data thus until send data to the sink node, utilizes routing table table simultaneously _k(K=1,2 ... m) record source node with data be sent to the sink node the node of process.In addition, can better carry out data fusion for guaranteeing data in transmitting procedure, make the priority of source node and bunch head higher than other node, avoid not having the node of data to waste energy as the via node forwarding data.Wherein, definite method of neighbor node priority is as follows:

After node has data to produce or receives data, according to the energy of neighbor node, determine the node of down hop apart from path energy consumption etc., i.e. node v _iSelect v _jPri function as the down hop neighbor node defines as shown in formula (4):

priority(j)＝pri _j1+pri _j2(4)

Node v _iNeighbor node v _jPriority form pri by two parts ₁And pri ₂The below defines respectively these two parts:

${\mathrm{<figure-callout\; id="1"\; label="pri\; j"\; filenames="DEST\_PATH\_HSB00001026256300022.png,DEST\_PATH\_HSB00001026256300041.png"\; state="\{\{state\}\}">pri</figure-callout>}}_j=\left\{\begin{array}{c}1,\mathrm{if}{v}_j\&Element;\mathrm{Sand}{d}_{j\_\sin k}<d_{i\_\mathrm{<figure-callout\; id="1"\; label="sin\; k"\; filenames="DEST\_PATH\_HSB00001026256300022.png,DEST\_PATH\_HSB00001026256300041.png"\; state="\{\{state\}\}">sin</figure-callout>}k}\\ 1,\mathrm{if}{v}_j\&Element;\mathrm{Cand}{d}_{j\_\sin k}<d_{i\_\mathrm{<figure-callout\; id="0"\; label="sin\; k"\; filenames="DEST\_PATH\_HSB00001026256300022.png,DEST\_PATH\_HSB00001026256300032.png"\; state="\{\{state\}\}">sin</figure-callout>}k}\\ 0,\mathrm{otherswise}\end{array}\right..---\left(5\right)$

S is node v _iAll neighbor node set, C is bunch head set in network, d _{J_sink}With d _{I_sink}Represent respectively node v _iWith node v _jTo the distance of sink node, pri _j1Be that 1 node more likely becomes next-hop node, guarantee data towards the direction transmission of sink node, as shown in Figure 2: node C more likely becomes next-hop node than Node B.In addition, the probability that source node and bunch head become next-hop node increases greatly, and effective like this fusion efficiencies that improved avoids not having the node of data to waste energy as the via node forwarding data.

pri ₂Distance and node v by dump energy, node and the sink node of node _iWith node v _jBetween communication cost jointly determine, be defined as follows respectively:

$e_j=\frac{E_{j\_\mathrm{<figure-callout\; id="0"\; label="residual\; E"\; filenames="DEST\_PATH\_HSB00001026256300022.png,DEST\_PATH\_HSB00001026256300032.png"\; state="\{\{state\}\}">residual</figure-callout>}}}{E_{}}.---\left(6\right)$

$r_j=\frac{R-d_{j\_\sin k}}{R}.---\left(7\right)$

${\cos t}_j=\frac{{\cos t}_{\max }-\cos t(v_i,v_j)}{{\cos t}_{\max }}.---\left(8\right)$

Wherein, e _jExpression node v _jDump energy E _{J_residual}Account for primary power E ₀Ratio, the probability that the node that dump energy is high becomes down hop increases greatly, avoids low-yield node to consume excessive power as the via node forwarding data, causes the too early dead energy consumption balance that guarantees nodes of node; r _jExpression v _jTo the distance of sink node and the relation of network radius, d _{J_sink}Larger priority is lower, and the assurance data are transmitted towards the direction of sink node, shorten transmission path.Cost _maxMaximum communication energy consumption in the expression communication range between two nodes, cost (v _i, v _j) be node v _iTo v _jCommunication energy consumption, cost _maxAnd cost (v _i, v _j) be expressed as follows respectively:

$\cos t(v_i,v_j)=\left\{\begin{array}{cc}{E}_{\mathrm{elec}}.k+(E_{\mathrm{elec}}.k+{\mathrm{\&epsiv;}}_{\mathrm{fs}}.k.{\left(d(v_i,v_j)\right)}^2),& \mathrm{ifd}(v_i,v_j)<d_0\\ E_{\mathrm{elec}}.k+(E_{\mathrm{elec}}.k+{\mathrm{\&epsiv;}}_{\mathrm{mp}}.k.{\left(d(v_i,v_j)\right)}^4),& \mathrm{ifd}(v_i,v_j)>{\mathrm{<figure-callout\; id="0"\; label="d"\; filenames="DEST\_PATH\_HSB00001026256300022.png,DEST\_PATH\_HSB00001026256300032.png"\; state="\{\{state\}\}">d</figure-callout>}}_0\end{array}\right..---\left(9\right)$

${\cos t}_{\max }=\left\{\begin{array}{cc}{E}_{\mathrm{elec}}.k+(E_{\mathrm{elec}}.k+{\mathrm{\&epsiv;}}_{\mathrm{fs}}.k.{R_{\max }}^2),& \mathrm{if}{R}_{\max }<d_0\\ E_{\mathrm{elec}}.k+(E_{\mathrm{elec}}.k+{\mathrm{\&epsiv;}}_{\mathrm{mp}}.k.{R_{\max }}^4),& \mathrm{if}{R}_{\max }>{\mathrm{<figure-callout\; id="0"\; label="d"\; filenames="DEST\_PATH\_HSB00001026256300022.png,DEST\_PATH\_HSB00001026256300032.png"\; state="\{\{state\}\}">d</figure-callout>}}_0\end{array}\right..---\left(10\right)$

R _maxMaximum communication distance for node.Sensor node receives the ENERGY E that k bit data consume _rx(k) be:

E _rx(k)＝k*E _elec(11)

Distance threshold d ₀Computing formula be;

${\mathrm{<figure-callout\; id="0"\; label="d"\; filenames="DEST\_PATH\_HSB00001026256300022.png,DEST\_PATH\_HSB00001026256300032.png"\; state="\{\{state\}\}">d</figure-callout>}}_0=\sqrt{\frac{{\mathrm{\&epsiv;}}_{\mathrm{fs}}}{{\mathrm{\&epsiv;}}_{\mathrm{mp}}}}.---\left(12\right)$

Wherein, sensor node electronic devices and components power consumption E _ElecRely on the factors such as digital coding, modulation, filtering, signal spread-spectrum, power amplifier power consumption ε _fs* d ²Perhaps ε _mp* d ⁴With arrive the relevant apart from d and acceptable bit error rate of receiver (bunch head or base station).

pri _j2＝α.e _j+β.r _j+γ.cost _i(13)

By (6) (7) (8) formula 0＜e as can be known _j＜1,0＜r _j＜1,0＜cost _j＜1.α, β, γ are respectively coefficient and alpha+beta+γ=1 between 0 to 1, so 0＜pri _j2＜1.

By (4)-(13) formula can see the consumption of outgoing link energy is less, dump energy is more, apart from sink node neighbor node more, the probability that is chosen as down hop is larger.

4 Algorithm Analysis

1) harmony of load Distribution

Wireless sensor network node distributes random, easily cause the uneven problem of energy consumption in network for even sub-clustering, the present invention utilizes node density and dump energy that the selection threshold value of bunch head is set, in a node compact district increase bunch quantity, bunch an establishment stage utilization bunch density and set up different bunch radiuses apart from the distance of sink node, reach the purpose of balance the whole network bunch scale.As shown in Figure 3, wherein circle is ordinary node, contains bunch head that is of " * " in circle, the position (100,200) of " * " expression sink node.The distribution that this shows bunch head is more even: the place that the node distribution is more intensive, and the distribution of bunch head is also more intensive, and the distribution of the place bunch head that the node distribution disperses also relatively disperses.Wherein, the density with node represents the sparse degree that nodes distributes.

2) in network, the transmission quantity of packet is few

In directed diffusion, interest message packet and probe data packet are all transmitted by the mode of flooding, so the data packet transmission amount in network is larger.The present invention not only reduces the transmission of interest bag by sub-clustering, also omit the transmission of detection packet, carries out again data fusion in transmission of data packets, has greatly reduced the transmission quantity of packet in network.Can find out very much according to the curve in Fig. 4, in the network of place of the present invention, the transmission quantity of packet obviously is less than DD and IDD.Reduce the network energy consumption generally from two aspects: the one, transmission path, the 2nd, transferring content namely reduces the transmission quantity of data.Therefore, the minimizing of data packet transmission amount in network can reduce energy consumption, improves energy utilization efficiency.

3) energy consumption balance is good

The present invention not only takes into full account each bunch Balance of load in clustering process, also take into full account the dump energy of nodes in data transmission procedure, avoids low-yield node to add the path.Fig. 5 is the energy consumption of three kinds of algorithms in each query task, can find out that the curve fluctuation of DD is maximum, and IDD takes second place, and the present invention is minimum, and little fluctuation reflects the harmony of good energy consumption.With regard to the amplitude of curve, be followed successively by from big to small: DD, IDD, the present invention, amplitude is less, and energy consumption is less.Simulation result shows, algorithm that this paper carries all is better than other two kinds of algorithms at energy efficiency and energy consumption balance.

4) capacity usage ratio is high

The operation wheel number that the present invention selects to remain gross energy and network in network compares with existing method as parameter, and Fig. 6 is under three kinds of algorithms, the comparison of residue gross energy in network.If the primary power of each node is 0.5J, in network, the initial gross energy of 100 nodes is 50J.Can find out that by analogous diagram residue of network organization gross energy of the present invention apparently higher than other two kinds of algorithms, effectively saved energy, improve capacity usage ratio.

5) network lifecycle is long

Network lifecycle is an important symbol weighing the network quality, it is one of topmost target of design routing algorithm, when 100 nodes are arranged in network, Fig. 7 (a) has carried out simulation comparison to the life cycle of three kinds of algorithms, as can be seen from the figure to take turns when taking turns with 239 first node of DD and IDD dead respectively when the network operation to 218, just lost efficacy when running to 1170 first nodes of the present invention when taking turns.By contrast, can find out that this paper algorithm has significantly extended network lifecycle.

6) more be applicable to large scale network

Fig. 7 (b) expands network range and is twice, and the interstitial content in network is increased to 200, and the network lifecycle of three kinds of algorithms is carried out emulation.By finding out with Fig. 6 contrast, along with the expansion of network size, the network lifecycle of DD is but shortening, and main cause is that the energy consumption that the blindness diffusion of the mode of flooding causes increases.By comparison, advantage of the present invention is more obvious.Illustrate that the present invention more is applicable to large scale network.

Claims (6)

1. the wireless sensor network multi-source data fusion method based on inquiry, mainly comprise network cluster dividing, interest diffusion, transfer of data three phases, it is characterized in that, the method comprises the following steps:

(1) network cluster dividing: in the election of cluster head stage, utilize the sparse degree of the dump energy of node and node region to guarantee the even distribution of bunch head; Bunch establishment stage in conjunction with the node density of each bunch region with construct apart from the distance of sink node bunch radius cluster that differs in size; Each bunch head is set up a bunch of member node information table, the ID of record bunch member node, dump energy, node coordinate, data acquisition type etc.;

(2) interest diffusion: the sink node periodically sends to all bunch heads by the mode of single-hop or multi-hop with interest message, after bunch head is received interest message, at first inquire about the own bunch member node information table of keeping, if there is the requirement of the data fit interest message that node gathers in bunch, in this bunch head is diffused into interest message bunch, if not indiffusion; Wherein, interest message is the specific descriptions to acquisition tasks, comprising: the parameters such as task type, target area, data transmission rate.

(3) transfer of data: the node of the data fit interest message of collection becomes source node, and each source node calculates the priority of all neighbor nodes, select priority high as next-hop node, until send data to the sink node.

2. as claimed in claim 1 based on the wireless senser multi-source data fusion method of inquiry, it is characterized in that at first carrying out the selection of bunch head in described step (1), at first each node chooses a random number between [0,1], with threshold value T (v _i) compare, if this number is less than threshold value T (v _i), node is elected as a bunch head, computational methods are as follows:

Wherein, p is the probability of the elected cluster head of node; R is the wheel number that loops at present; G also was not elected to the node set of cluster head in nearest 1/p wheel; α _iExpression node v _iDensity, Neighbor (v _i) _ alive and Network_alive represent respectively node v _iNeighbor node and whole network in the number of survival node, namely dump energy is greater than 0 number, E ₀And E _{I_residual}The primary power and the dump energy that represent respectively node.

3. as claimed in claim 1 based on the wireless senser multi-source data fusion method of inquiry, it is characterized in that in described step (1), bunch establishment stage, each bunch head calculates it to the approximate distance of sink node according to the intensity that receives signal

And definite its bunch radius R _Hi, the maximum bunch radius of order bunch head is R ₀, the radius calculation formula of a bunch head is as follows:

Wherein, α _HiBe a bunch H _iDensity, value between 0～1, d _maxAnd d _minRepresent that respectively bunch head in network is to the minimum and maximum distance of sink node, d _{Hi_sink}An expression bunch H _iDistance with the sink node.

4. as claimed in claim 1 based on the wireless senser multi-source data fusion method of inquiry, it is characterized in that in described step (3), each source node calculates the priority of all neighbor nodes, select priority high as next-hop node.Pri function is comprised of two parts, and in first, the priority of bunch head and source node is higher, adopts following formula to determine priority:

S is node v _iAll neighbor node set, C is bunch head set in network, d _{I_sink}With d _{I_sink}Represent respectively node v _iWith node v _iTo the distance of sink node, pri _j1Be that 1 node more likely becomes next-hop node, guarantee data towards the direction transmission of sink node, in addition, the probability that source node and bunch head become next-hop node increases greatly, avoids not having the node of data to waste energy as the via node forwarding data.

5. as claimed in claim 1 based on the wireless senser multi-source data fusion method of inquiring about, it is characterized in that in described step (3), each source node calculates the priority of all neighbor nodes, select priority high as next-hop node, pri function is comprised of two parts, in second portion, pri ₂Distance and node v by dump energy, node and the sink node of node _iWith node v _jBetween communication cost jointly determine, be defined as follows respectively:

Wherein, e _jExpression node v _jDump energy E _{J_residual}Account for primary power E ₀Ratio, avoid low-yield node to consume excessive power as the via node forwarding data, cause the too early dead energy consumption balance that guarantees nodes of node; r _jExpression v _iTo the distance of sink node and the relation of network radius, d _{J_sink}Larger priority is lower, and the assurance data are transmitted towards the direction of sink node, shorten transmission path; Cost _maxMaximum communication energy consumption in the expression communication range between two nodes, cost (v _i, v _j) be node v _iTo v _jCommunication energy consumption, cost _maxAnd cost (v _i, v _j) be expressed as follows respectively:

R _maxBe the maximum communication distance of node, sensor node receives the ENERGY E that k bit data consume _rx(k) be:

E _rx(k)＝k*E _elec，

Distance threshold d ₀Computing formula be:

Wherein, sensor node electronic devices and components power consumption E _ElecRely on the factors such as digital coding, modulation, filtering, signal spread-spectrum, power amplifier power consumption ε _fs* d ²Perhaps ε _mp* d ⁴With arrive the relevant apart from d and acceptable bit error rate of receiver (cluster head or base station).

6. as claimed in claim 1 based on the wireless senser multi-source data fusion method of inquiry, it is characterized in that in described step (3) that following formula is adopted in the establishment of priority:

pri _j2＝α.e _j+β.r _j+γ.cost _j，

priority(j)＝pri _j1+pri _j2，

Wherein, 0＜e _j＜1,0＜r _j＜1,0＜cost _i＜1, α, β, γ are respectively coefficient and alpha+beta+γ=1, the 0＜pri between 0 to 1 _j2＜1,0＜priority (j)＜2.

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