CN104219683A - Method and system for deploying renewable energy nodes of wireless sensor networks of farmlands - Google Patents

Abstract

The invention provides a method and a system for deploying renewable energy nodes of wireless sensor networks of farmlands, and relates to the technical field of wireless sensor networks of farmlands. The method includes deploying ordinary battery nodes in monitoring regions; determining the quantity of to-be-deployed renewable energy nodes according to a preset cost and the quantity of the ordinary battery nodes; traversing the ordinary battery nodes; replacing a to-be-replaced node by a renewable energy node; subtracting the quantity of the to-be-deployed renewable energy nodes by one; judging whether the quantity of the to-be-deployed renewable energy nodes is zero or not; completing a process if the quantity of the to-be-deployed renewable energy nodes is zero, or deploying a next renewable energy node if the quantity of the to-be-deployed renewable energy nodes is not zero. The ordinary battery node corresponding to the maximum expected dispensable energy consumption is used as the to-be-replaced node. The method and the system have the advantages that the problem of constraints of preset costs in farmland monitoring application in the prior art can be solved by the aid of the method, and the service lives of the networks can be prolonged to the greatest extent.

Description

Farmland wireless sensor network regenerative resource node deployment method and system

Technical field

The present invention relates to farmland wireless sensor network technical field, relate in particular to a kind of farmland wireless sensor network regenerative resource node deployment method and system.

Background technology

Farmland wireless sensor network (Wireless Sensor Network is called for short WSN) can facilitate, accurately obtain the real time environment information of agricultural production, has become guiding agricultural production, improves the key technology of crop yield.Existing farmland wireless sensor network node adopts powered battery mode, has serious energy constraint, is wireless sensor network at one of application bottleneck of extensive farm environment monitoring.In addition, in farmland wireless sensor network environmental monitoring application, exist wireless sensor network node quantity many, dispose area greatly and the problem such as skewness, battery altering is extremely bothered.Therefore, Power supply problem becomes the matter of utmost importance of restriction farmland wireless sensor network development.

In recent years, renewable energy source node becomes the new approaches of wireless sensor network research, and resources such as the solar energy in introducing farm environment, wind energy solves the problem of farmland wireless sensor network Power supply.In the regenerative resource node deployment method of prior art, first for common batteries node, dispose, then by the main node after disposing is carried out to regenerative resource node replacement, complete the deployment of renewable energy source node.

Yet said method has been simple qualitative analysis energy consumption problem, does not carry out position and the association analysis of network energy consumption of renewable energy source node, draws best regenerative resource node location; In addition, prior art does not limit the quantity of renewable energy source node, is all equipped with on demand, does not consider default cost restricted problem, cannot carry out practical application; Finally, farmland wireless sensor network node is not The more the better, and prior art does not consider to the marginal benefit of network lifecycle how whether a newly-increased renewable energy source node, exist the equilibrium point problem between cost and network life.

Summary of the invention

For defect of the prior art, the invention provides a kind of farmland wireless sensor network node deployment method and system, solve the problem of default cost constraint in the monitoring and measuring application of farmland, and extended to greatest extent network life.

On the one hand, the invention provides a kind of farmland wireless sensor network node deployment method, comprising:

S1, in monitored area, dispose common batteries node;

The quantity of S2, the default cost of basis and common batteries node is determined regenerative resource number of nodes to be disposed;

S3, travel through described common batteries node, when calculating is renewable energy source node by the current common batteries node replacement traversing, it can energy efficient to the expectation of periphery common batteries node, using maximum expectation can the corresponding common batteries node of energy efficient as node to be replaced;

S4, by described node replacement to be replaced, be renewable energy source node, and will described in regenerative resource number of nodes to be disposed subtract 1, whether regenerative resource number of nodes to be disposed is 0 described in judgement, if so, process ends, otherwise return to step S3.

Alternatively, in described step S3, described expectation can energy efficient be calculated by following formula,

${\mathrm{Esave}}_i=\underset{j=1}{\overset{n_i}{\mathrm{\Σ}}}{\mathrm{Pr}}_j-n_i(l.{\mathrm{\ϵ}}_{\mathrm{fs}}.{R_s}^2+l.E_{\mathrm{ele}})$

Wherein, Esave _ifor expectation corresponding to current common batteries node i can energy efficient, Pr _jfor the expectation energy consumption of j periphery common batteries node of current common batteries node i, n _ifor the node degree of current common batteries node i, n _jfor the node degree of j periphery common batteries node of current common batteries node i, l is the data length that the collection of current common batteries node i is uploaded, R _sfor the communication radius of common batteries node, ε _fsfor common batteries node carries out R _sdecay factor while communicating by letter in radius, ε _mpdecay factor while communicating by letter with other renewable energy source nodes or aggregation node for common batteries node,, E _elefor the power consumption of current common batteries node i inter-process circuit, d _jfor j periphery common batteries node of the current common batteries node i distance to aggregation node.

Alternatively, in described step S3, the expectation of described maximum can specifically be comprised as node to be replaced by the corresponding common batteries node of energy efficient:

Whether the expectation that judges described maximum can the corresponding common batteries node of energy efficient unique, if so, using the expectation of described maximum can the corresponding common batteries node of energy efficient as node to be replaced; Otherwise in common batteries node corresponding to the energy efficient expected of choosing described maximum with farthest one of aggregation node distance as node to be replaced.

Alternatively, between described step S3 and described step S4, also comprise:

A101: using described node to be replaced as cluster head, adopt dynamic clustering method to generate regenerative resource bunch;

A102: if described regenerative resource bunch exists isolated island node, described node location to be replaced is adjusted.

Alternatively, in described steps A 102, described regenerative resource node location to be replaced is adjusted specifically and is comprised:

Described in traversal, treat the neighbor node of battery node, find the neighbor node set v that comprises all isolated island nodes ₁;

If described neighbor node set v ₁in only have a neighbor node, using this neighbor node as new node to be replaced, and perform step S4, otherwise find described neighbor node set v ₁middle expectation can energy efficient maximum neighbor node set v ₂;

If described neighbor node set v ₂in only have a neighbor node, using this neighbor node as new node to be replaced, and perform step S4, otherwise find described neighbor node set v ₂in can reach the neighbor node set v of neighbor node quantity maximum ₃;

If described neighbor node set v ₃in only have a neighbor node, using this neighbor node as new node to be replaced, and perform step S4, otherwise find described neighbor node set v ₃in the neighbor node nearest with described nodal distance to be replaced, using this neighbor node as new node to be replaced.

Alternatively, between described step S3 and described step S4, also comprise:

Marginal benefit when calculating is renewable energy source node by described node replacement to be replaced, judges whether described marginal benefit is not more than preset value; If so, direct process ends, otherwise execution step S4;

Wherein, described marginal benefit is according to EL _beforeand EL _aftercalculate and obtain, EL _beforefor the network life expectancy of described node to be replaced, EL _afternetwork life expectancy when described node replacement to be replaced is renewable energy source node.

Alternatively, described marginal benefit is calculated by following formula,

EL _mr＝EL _before-EL _after

Wherein, e ₀for the primary power of common batteries node, E _nfor the expectation energy consumption of node to be replaced, E _mexpectation energy consumption when described node replacement to be replaced is renewable energy source node, described node m is for expecting the node that energy consumption is the highest in other nodes except described node to be replaced.

On the other hand, the invention provides a kind of farmland wireless sensor network regenerative resource node deployment system, comprising:

Common batteries node deployment unit, for disposing common batteries node in monitored area;

Determining unit, for determining regenerative resource number of nodes to be disposed according to the quantity of default cost and common batteries node;

Unit to be replaced, be used for traveling through described common batteries node, when calculating is renewable energy source node by the current common batteries node replacement traversing, it can energy efficient to the expectation of periphery common batteries node, using maximum expectation can the corresponding common batteries node of energy efficient as node to be replaced;

The first identifying unit, for being renewable energy source node by described node replacement to be replaced, and will described in regenerative resource number of nodes to be disposed subtract 1, whether regenerative resource number of nodes to be disposed is 0 described in judgement.

Alternatively, described system also comprises:

Generation unit, for using described node to be replaced as cluster head, adopts dynamic clustering method to generate regenerative resource bunch;

Adjustment unit, if there is isolated island node in described regenerative resource bunch, for described node location to be replaced is adjusted.

Alternatively, described system also comprises:

The second judging unit, the marginal benefit while described node replacement to be replaced being renewable energy source node for calculating, judges whether described marginal benefit is not more than preset value.

As shown from the above technical solution, farmland wireless sensor network regenerative resource node deployment method of the present invention and system, while the current common batteries node replacement traversing being renewable energy source node by calculating, it can energy efficient to the expectation of periphery common batteries node, finding out maximum expectation can energy efficient, by the expectation of described maximum, can the corresponding common batteries node replacement of energy efficient be renewable energy source node, solve the problem of default cost constraint in the monitoring and measuring application of farmland, and extended to greatest extent network life.

Accompanying drawing explanation

The schematic flow sheet of the farmland wireless sensor network regenerative resource node deployment method that Fig. 1 provides for first embodiment of the invention;

The schematic flow sheet of the farmland wireless sensor network regenerative resource node deployment method that Fig. 2 provides for second embodiment of the invention;

Farmland wireless sensor network regenerative resource node deployment position and position adjustment figure thereof that Fig. 3 provides for second embodiment of the invention;

The farmland wireless sensor network life cycle that Fig. 4 provides for second embodiment of the invention and marginal benefit are with regenerative resource number of nodes variation diagram;

The structural representation of the farmland wireless sensor network regenerative resource node deployment system that Fig. 5 provides for third embodiment of the invention.

Embodiment

Below in conjunction with drawings and Examples, the specific embodiment of the present invention is described in further detail.Following examples are used for illustrating the present invention, but are not used for limiting the scope of the invention.

Fig. 1 shows the schematic flow sheet of the farmland wireless sensor network regenerative resource node deployment method that first embodiment of the invention provides, and as shown in Figure 1, the farmland wireless sensor network regenerative resource node deployment method of the present embodiment is as described below.

S1, in monitored area, dispose common batteries node.

In this step, it should be noted that before carrying out common batteries node deployment, need to build a network topology structure, according to the connectedness of network self and the deployment of the coverage of monitored area being carried out to common batteries node.

For instance, the covering radius of note common batteries node is R _c, communication radius is R _s, the average distance between node time can reach the balance between number of nodes and coverage, note monitored area area is A, now the deployment common batteries number of nodes under default cost constraint is:

$N_0=\frac{A}{\mathrm{\π}{\left(\frac{\sqrt{3}}{2}{R}_c\right)}^2}$

Adopt prior art to dispose above-mentioned common batteries node, for instance, the present embodiment adopts the mode of random placement to carry out common batteries node deployment, make common batteries node after disposing meet the requirement of the connectedness of network in monitored area and the coverage of monitored area interior nodes, can use other node deployment methods, the present embodiment does not limit the dispositions method of described common batteries node yet.

S2, the default cost of basis and common batteries number of nodes are determined regenerative resource number of nodes to be disposed.

In this step, will be understood that, farmland monitoring has strict default cost constraint in actual applications, that is to say because default cost is limited, can not carry out regenerative resource node deployment by the ideal quantity of prior art, therefore, need to find out a maximum quantity that allows to dispose renewable energy source node within the scope of default cost.

For instance, remember that total default cost is C _t, the cost of single common batteries node is C _b, the cost of single renewable energy source node is C _r, common batteries number of nodes is N ₀, calculate the points N of regenerative resource node deployment _rfor:

$N_r=\frac{C_t-C_b.N_0}{C_r-C_b}$

S3, travel through described common batteries node, when calculating is renewable energy source node by the current common batteries node replacement traversing, it can energy efficient to the expectation of periphery common batteries node, using maximum expectation can the corresponding common batteries node of energy efficient as node to be replaced.

In this step, it should be noted that described periphery common batteries node refers to while replacing with renewable energy source node communication radius at R _scommon batteries node in scope.

Particularly, travel through all common batteries nodes in described monitored area, find out the maximum that expectation when each common batteries node replacement is renewable energy source node can energy efficient;

Using can the energy efficient maximum corresponding common batteries node of described expectation as node to be replaced.

S4, by described node replacement to be replaced, be renewable energy source node, and will described in regenerative resource number of nodes to be disposed subtract 1, whether regenerative resource number of nodes to be disposed is 0 described in judgement, if so, process ends, otherwise return to step S3.

In this step, if described in the quantity of renewable energy source node to be disposed be not 0, except completing the renewable energy source node of deployment, residue renewable energy source node is continued to execution step S3, carry out the deployment of next renewable energy source node, if described in the quantity of renewable energy source node to be disposed be 0, complete the deployment of all renewable energy source nodes, process ends.

The farmland wireless sensor network regenerative resource node deployment method of the present embodiment, by dispose common batteries node in monitored area, and then determine regenerative resource number of nodes to be disposed according to default cost and common batteries number of nodes, travel through described common batteries node, when calculating is renewable energy source node by the current common batteries node replacement traversing, it can energy efficient to the expectation of periphery common batteries node, using maximum expectation can the corresponding common batteries node of energy efficient as node to be replaced, by described node replacement to be replaced, it is renewable energy source node, and described in inciting somebody to action, regenerative resource number of nodes to be disposed subtracts 1, described in judgement, whether regenerative resource number of nodes to be disposed is 0, if, process ends, otherwise dispose next renewable energy source node.Said method can be disposed accordingly for the renewable energy source node of varying number thus, renewable energy utilization can be maximized, and has reduced the actual consumption of battery simultaneously, obtains maximum network life.

Fig. 2 shows the schematic flow sheet of the farmland wireless sensor network regenerative resource node deployment method that second embodiment of the invention provides, and as shown in Figure 2, the farmland wireless sensor network regenerative resource node deployment method of the present embodiment is as described below.

201, in monitored area, carry out common batteries node deployment.

In this step, it should be noted that the present embodiment is by the basis of prior art common batteries node deployment, to optimum common batteries node, adopt renewable energy source node to replace to solve farmland in prior art to be preset to the problem of this constraint.Thereby, first need in monitored area, carry out the deployment of common batteries node, this step is as shown in (a) in Fig. 3.

202, according to default cost and common batteries number of nodes, determine regenerative resource number of nodes to be disposed.

In this step, for instance, the regenerative resource that the present embodiment proposes includes but not limited to solar energy, wind energy etc., can specifically determine according to the on-site regenerative resource situation in farmland.

Conventionally, restriction due to default cost, the quantity of renewable energy source node also has certain restriction, in carrying out the deployment of renewable energy source node, how to make each renewable energy source node of disposing as much as possible prolong network lifetime be the important inventive point of the present embodiment.

Further, for the node energy consumption under different condition and network life accurately calculate, need the first routing mode of specified data transmission.

For instance, in plane routing mode, apart from the nearer node of aggregation node, need to bear the data retransmission task of whole remote nodes, and for the large-scale application scene of farmland wireless sensor network and the situation more than number of nodes, the energy of all mid-side nodes of aggregation node can be consumed rapidly, and then shorten network life.

In hierarchical cluster routing mode, by cluster head, one redirect of the data of bunch interior nodes is sent to aggregation node, due to long transmission distance, so cluster head energy consumption is significantly higher than other nodes.

The deficiency existing based on above-mentioned two kinds of methods, the present embodiment adopts the dynamic clustering method based on cluster head rotation, has limited a bunch interior nodes quantity, cluster head additionally can be consumed energy average between bunch interior nodes, to extend network lifecycle.

203, travel through described common batteries node, when calculating is renewable energy source node by the current common batteries node replacement traversing, it can energy efficient to the expectation of periphery common batteries node, using maximum expectation can the corresponding common batteries node of energy efficient as node to be replaced.

In this step, the expectation of described maximum can specifically be comprised as node to be replaced by the corresponding common batteries node of energy efficient:

Whether the expectation that judges described maximum can the corresponding common batteries node of energy efficient be one, if so, using the expectation of described maximum can the corresponding common batteries node of energy efficient as node to be replaced; Otherwise in common batteries node corresponding to the energy efficient expected of choosing described maximum with farthest one of aggregation node distance as node to be replaced.

Alternatively, according to the expectation energy consumption of common batteries node, described in when obtaining described common batteries node replacement and being renewable energy source node, node can energy efficient to the expectation of periphery common batteries node, find out and can expect energy consumption maximum, as shown in (b) in Fig. 3, node a in figure is that maximum expectation can common batteries node location corresponding to energy efficient, is node to be replaced.

Alternatively, note for bunch in by common batteries node, form bunch in maximum to allow number of nodes be A ₁, for take that renewable energy source node is cluster head bunch in maximum to allow number of nodes be A ₂, A ₂>A ₁, for instance, in the present embodiment, A ₁=10, A ₂=50, note n _kfor the node degree of current common batteries node k, d _kfor the distance of current common batteries node k to aggregation node, R _sdistance during for common batteries node communication, is also the communication radius of determining periphery common batteries range of nodes, draws when without renewable energy source node, and the probability that each common batteries node k is elected as cluster head is so the expectation energy consumption of current common batteries node k is:

${\mathrm{Pr}}_k=l.E_{\mathrm{ele}}+\frac{n_k}{n_k+1}(l.{\mathrm{\ϵ}}_{\mathrm{fs}}.{R_s}^2)+l.{\mathrm{\ϵ}}_{\mathrm{mp}}.d_k^4$

Wherein, l is that current common batteries node k gathers the data length of uploading, ε _fsfor common batteries node carries out R _sdecay factor during radius communication, ε _mpdecay factor while communicating by letter with other renewable energy source nodes or aggregation node for common batteries node;

For instance, in the present embodiment, l=1000bit, E _ele=50nJ/bit,, ε _fs=10pJ/bit/m ², ε _mp=0.0013pJ/bit/m ⁴.

Alternatively, for any common batteries node i, replaced with after renewable energy source node, calculate it and to the expectation of periphery common batteries node can energy efficient be:

${\mathrm{Esave}}_i=\underset{j=1}{\overset{n_i}{\mathrm{\Σ}}}{\mathrm{Pr}}_j-n_i(l.{\mathrm{\ϵ}}_{\mathrm{fs}}.{R_s}^2+l.E_{\mathrm{ele}})$

Wherein, Esave _ifor expectation corresponding to current common batteries node i can energy efficient, Pr _jfor average every expectation energy consumption of taking turns of j periphery common batteries node of current common batteries node i, n _inode degree for current common batteries node i.

204,, using described node to be replaced as cluster head, adopt dynamic clustering method to generate regenerative resource bunch.

In this step, it should be noted that and adopt dynamic clustering method as cluster head, to generate regenerative resource bunch to described node to be replaced, if select, add the number of nodes of this bunch to exceed maximum allowable quantity A ₂in selecting to add the node of this regenerative resource bunch by the distance-taxis of this nodal distance aggregation node, distance more preferentially adds this regenerative resource bunch, until all nodes all add regenerative resource bunch, or the number of nodes adding exceeds maximum allowable quantity A ₂if, exist and can select to add the quantity of regenerative resource node cluster to surpass the node of 1, according to the quantity of bunch interior nodes, select to add bunch few regenerative resource bunch of interior nodes quantity.

If 205 described regenerative resources bunch exist isolated island node, described node location to be replaced is adjusted.

In this step, it should be noted that, because dynamic clustering routing infrastructure easily produces a small amount of " isolated island node ", and " isolated island node " is due to away from aggregation node, transmit energy consumption large, and quantity is few, and extra cluster head communication energy consumption cannot on average obtain the longer node life-span by a large amount of bunches of interior nodes, so, the renewable energy source node of replacing is carried out after cluster, be necessary to eliminate newly-generated " isolated island node ".

For certain common batteries node, if full condition: described node b does not belong to any one regenerative resource bunch, and at node b to arbitrary multihop path of aggregation node, all exist certain node w to belong to certain regenerative resource bunch, claim node b for " isolated island node ".Described " isolated island node " may be one, also may be a plurality of adjacent, conventionally " isolated island node " appear at bunch and bunch between crack or the edge of monitored area, farmland, as shown in (c) in Fig. 3, wherein, node c is the cluster head node of current regenerative resource bunch;

Alternatively, described adjustment specifically comprises:

Described in traversal, treat the neighbor node of battery node, find the neighbor node set v that comprises all isolated island nodes ₁;

If described neighbor node set v ₁in only have a neighbor node, using this neighbor node as new node to be replaced, and perform step S4, otherwise find described neighbor node set v ₁middle expectation can energy efficient maximum neighbor node set v ₂;

If described neighbor node set v ₂in only have a neighbor node, using this neighbor node as new node to be replaced, and perform step S4, otherwise find described neighbor node set v ₂in can reach the neighbor node set v of neighbor node quantity maximum ₃;

If described neighbor node set v ₃in only have a neighbor node, using this neighbor node as new node to be replaced, and perform step S4, otherwise find described neighbor node set v ₃in the neighbor node nearest with described nodal distance to be replaced, using this neighbor node as new node to be replaced.

Choose the position of the neighbor node d that meets above-mentioned condition, using described neighbor node d as new node to be replaced, as shown in (d) in Fig. 3.

206, calculate marginal benefit when described node replacement to be replaced is renewable energy source node, judge whether described marginal benefit is not more than preset value; If so, direct process ends, otherwise execution step 207.

In this step, get rid of all renewable energy source nodes and be the common batteries node in the regenerative resource that generates of cluster head bunch by renewable energy source node, to other node calculation expectation energy consumptions, and select maximum, according to the maximum of described other node expectation energy consumptions, network life expectancy when calculating the network life expectancy of described node to be replaced and described node replacement to be replaced being renewable energy source node, according to described network life expectancy, draw marginal benefit when node replacement to be replaced is renewable energy source node, judge whether described marginal benefit is not more than preset value, if, cancel the deployment of present node, direct process ends, otherwise execution step 207.

The primary power of note common batteries node is E ₀, the expectation energy consumption of node to be replaced is E _nso the network life expectancy of described replacement common batteries node is:

${\mathrm{EL}}_{\mathrm{before}}=\frac{E_0}{E_n}$

Expectation energy consumption when note is renewable energy source node by node replacement to be replaced is E _m, described node m is for expecting the node that energy consumption is the highest in other nodes except described node to be replaced, so network life expectancy when described node replacement to be replaced is renewable energy source node is:

${\mathrm{EL}}_{\mathrm{after}}=\frac{E_0}{E_m}$

For instance, the computational methods of the marginal benefit of the present embodiment are as follows,

EL _mr＝EL _before-EL _after

The computational methods that it should be noted that the marginal benefit in the present embodiment are subtraction form, but in actual applications, the present invention does not limit the computational methods of marginal benefit, can be division form yet, specifically according to actual conditions, determine.

Will be understood that, along with the increase of default cost, allow the maximum quantity of disposing renewable energy source node also to increase, marginal benefit EL thereupon _mrreduce gradually, when marginal benefit is less than or equal to preset value, continues to increase cost income the effect of network life will be weakened or disappear.

Fig. 4 shows farmland wireless sensor network life cycle that second embodiment of the invention provides and marginal benefit with regenerative resource number of nodes variation diagram, as shown in Figure 4, increase along with renewable energy source node ratio, marginal benefit reduces gradually, network lifecycle tends towards stability, therefore, when the renewable energy source node of disposing reaches some, continue to dispose renewable energy source node constant on the impact of network lifecycle, that is to say, then continue to dispose the life expectancy that renewable energy source node can not extend network.

For instance, in the present embodiment, the preset value of marginal benefit is 0, when the marginal benefit when node replacement to be replaced is renewable energy source node is not more than 0, continue to increase cost drop into remove to dispose renewable energy source node can not prolong network lifetime, the renewable energy source node after disposing weakens or disappears the influence of network life, cancels the deployment of renewable energy source node, directly process ends.

207, by described node replacement to be replaced, be renewable energy source node, and will described in regenerative resource number of nodes to be disposed subtract 1, whether regenerative resource number of nodes to be disposed is 0 described in judgement, if so, process ends, otherwise return to step 203.

In this step, above-mentioned farmland wireless sensor network regenerative resource node deployment method, by default cost, draw the maximum regenerative resource number of nodes that allows deployment, with expectation, can energy efficient find out the optimal location of disposing renewable energy source node again, and adopt the optimal location of adjustment and deployment renewable energy source node to eliminate " isolated island node ", solved and become the problem of clustering architecture on coverage, make the renewable energy source node of each deployment all realize the energy consumption of large as far as possible reduction common batteries, and the network life finally reaching under default cost constraint maximizes.

Fig. 5 shows the structural representation of the farmland wireless sensor network regenerative resource node deployment system that third embodiment of the invention provides, as shown in Figure 5, the farmland wireless sensor network regenerative resource node deployment system in the present embodiment comprises: common batteries node deployment unit 51, determining unit 52, replacement unit 53 and the first identifying unit 54;

Wherein, described common batteries node deployment module 51 for disposing common batteries node in monitored area;

Described determining unit 52 is for determining regenerative resource number of nodes to be disposed according to default cost and common batteries number of nodes;

Described replacement unit 53 is for traveling through described common batteries node, when calculating is renewable energy source node by the current common batteries node replacement traversing, it can energy efficient to the expectation of periphery common batteries node, using maximum expectation can the corresponding common batteries node of energy efficient as node to be replaced;

Described the first identifying unit 54 is for being renewable energy source node by described node replacement to be replaced, and will described in regenerative resource number of nodes to be disposed subtract 1, whether regenerative resource number of nodes to be disposed is 0 described in judgement.

Alternatively, described system also comprises: generation unit and adjustment unit;

Described generation unit, for using described node to be replaced as cluster head, adopts dynamic clustering method to generate regenerative resource bunch;

Described adjustment unit is when there is isolated island node in described regenerative resource bunch, for described node location to be replaced is adjusted.

Described adjustment unit, specifically comprises:

Described in traversal, treat the neighbor node of battery node, find the neighbor node set v that comprises all isolated island nodes ₁;

If described neighbor node set v ₁in only have a neighbor node, using this neighbor node as new node to be replaced, and carry out the first identifying unit 54, otherwise find described neighbor node set v ₁middle expectation can energy efficient maximum neighbor node set v ₂;

If described neighbor node set v ₂in only have a neighbor node, using this neighbor node as new node to be replaced, and carry out the first identifying unit 54, otherwise find described neighbor node set v ₂in can reach the neighbor node set v of neighbor node quantity maximum ₃;

If described neighbor node set v ₃in only have a neighbor node, using this neighbor node as new node to be replaced, and carry out the first identifying unit 54, otherwise find described neighbor node set v ₃in the neighbor node nearest with described nodal distance to be replaced, using this neighbor node as new node to be replaced.

Alternatively, described system also comprises: the second judging unit;

Described the second judging unit, for calculating marginal benefit when described node replacement to be replaced is renewable energy source node, judges whether described marginal benefit is not more than preset value.

The farmland wireless senser regenerative resource node deployment system of the present embodiment is after completing deployment, marginal benefit to each renewable energy source node after disposing is assessed, when according to cost, raising reaches the flex point of marginal revenue curve, can stop disposing regenerative resource node, reducing unnecessary cost drops into, to solve the problem of default cost constraint in the monitoring and measuring application of farmland, reach the game equilibrium of default cost and network life, extended to greatest extent network life.

Finally it should be noted that: each embodiment, only in order to technical scheme of the present invention to be described, is not intended to limit above; Although the present invention is had been described in detail with reference to aforementioned each embodiment, those of ordinary skill in the art is to be understood that: its technical scheme that still can record aforementioned each embodiment is modified, or some or all of technical characterictic is wherein equal to replacement; And these modifications or replacement do not make the essence of appropriate technical solution depart from the scope of the claims in the present invention.

Claims (10)

1. a farmland wireless sensor network regenerative resource node deployment method, is characterized in that, comprising:

S1, in monitored area, dispose common batteries node;

The quantity of S2, the default cost of basis and common batteries node is determined regenerative resource number of nodes to be disposed;

S3, travel through described common batteries node, when calculating is renewable energy source node by the current common batteries node replacement traversing, it can energy efficient to the expectation of periphery common batteries node, using maximum expectation can the corresponding common batteries node of energy efficient as node to be replaced;

S4, by described node replacement to be replaced, be renewable energy source node, and will described in regenerative resource number of nodes to be disposed subtract 1, whether regenerative resource number of nodes to be disposed is 0 described in judgement, if so, process ends, otherwise return to step S3.

2. method according to claim 1, is characterized in that, in described step S3, described expectation can energy efficient be calculated by following formula,

${\mathrm{Esave}}_i=\underset{j=1}{\overset{n_i}{\mathrm{\Σ}}}{\mathrm{Pr}}_j-n_i(l.{\mathrm{\ϵ}}_{\mathrm{fs}}.{R_s}^2+l.E_{\mathrm{ele}})$

Wherein, Esave _ifor expectation corresponding to current common batteries node i can energy efficient, Pr _jfor the expectation energy consumption of j periphery common batteries node of current common batteries node i, n _ifor the node degree of current common batteries node i, n _jfor the node degree of j periphery common batteries node of current common batteries node i, l is the data length that the collection of current common batteries node i is uploaded, R _sfor the communication radius of common batteries node, ε _fsfor common batteries node carries out radius R _sdecay factor during interior communication, ε _mpdecay factor while communicating by letter with other renewable energy source nodes or aggregation node for common batteries node, E _elefor the power consumption of current common batteries node i inter-process circuit, d _jfor j periphery common batteries node of the current common batteries node i distance to aggregation node.

3. method according to claim 1, is characterized in that, in described step S3, the expectation of described maximum can specifically be comprised as node to be replaced by the corresponding common batteries node of energy efficient:

Whether the expectation that judges described maximum can the corresponding common batteries node of energy efficient unique, if so, using the expectation of described maximum can the corresponding common batteries node of energy efficient as node to be replaced; Otherwise in common batteries node corresponding to the energy efficient expected of choosing described maximum with farthest one of aggregation node distance as node to be replaced.

4. method according to claim 1, is characterized in that, between described step S3 and described step S4, also comprises:

A101: using described node to be replaced as cluster head, adopt dynamic clustering method to generate regenerative resource bunch;

A102: if described regenerative resource bunch exists isolated island node, described node location to be replaced is adjusted.

5. method according to claim 4, is characterized in that, in described steps A 102, described regenerative resource node location to be replaced is adjusted specifically and is comprised:

Described in traversal, treat the neighbor node of battery node, find the neighbor node set v that comprises all isolated island nodes ₁;

If described neighbor node set v ₁in only have a neighbor node, using this neighbor node as new node to be replaced, and perform step S4, otherwise find described neighbor node set v ₁middle expectation can energy efficient maximum neighbor node set v ₂;

If described neighbor node set v ₂in only have a neighbor node, using this neighbor node as new node to be replaced, and perform step S4, otherwise find described neighbor node set v ₂in can reach the neighbor node set v of neighbor node quantity maximum ₃;

If described neighbor node set v ₃in only have a neighbor node, using this neighbor node as new node to be replaced, and perform step S4, otherwise find described neighbor node set v ₃in the neighbor node nearest with described nodal distance to be replaced, using this neighbor node as new node to be replaced.

6. according to the method described in any one in claim 1-5, it is characterized in that, between described step S3 and described step S4, also comprise:

Marginal benefit when calculating is renewable energy source node by described node replacement to be replaced, judges whether described marginal benefit is not more than preset value; If so, direct process ends, otherwise execution step S4;

Wherein, described marginal benefit is according to EL _beforeand EL _aftercalculate and obtain, EL _beforefor the network life expectancy of described node to be replaced, EL _afternetwork life expectancy when described node replacement to be replaced is renewable energy source node.

7. method according to claim 6, is characterized in that, described marginal benefit is calculated by following formula,

EL _mr＝EL _before-EL _after

Wherein, e ₀for the primary power of common batteries node, E _nfor the expectation energy consumption of node to be replaced, E _mexpectation energy consumption when described node replacement to be replaced is renewable energy source node, described node m is for expecting the node that energy consumption is the highest in other nodes except described node to be replaced.

8. a farmland wireless sensor network regenerative resource node deployment system, is characterized in that, comprising:

Common batteries node deployment unit, for disposing common batteries node in monitored area;

Determining unit, for determining regenerative resource number of nodes to be disposed according to the quantity of default cost and common batteries node;

Unit to be replaced, be used for traveling through described common batteries node, when calculating is renewable energy source node by the current common batteries node replacement traversing, it can energy efficient to the expectation of periphery common batteries node, using maximum expectation can the corresponding common batteries node of energy efficient as node to be replaced;

The first identifying unit, for being renewable energy source node by described node replacement to be replaced, and will described in regenerative resource number of nodes to be disposed subtract 1, whether regenerative resource number of nodes to be disposed is 0 described in judgement.

9. system according to claim 8, is characterized in that, described system also comprises:

Generation unit, for using described node to be replaced as cluster head, adopts dynamic clustering method to generate regenerative resource bunch;

Adjustment unit, if there is isolated island node in described regenerative resource bunch, for described node location to be replaced is adjusted.

10. system according to claim 8, is characterized in that, described system also comprises:

The second judging unit, the marginal benefit while described node replacement to be replaced being renewable energy source node for calculating, judges whether described marginal benefit is not more than preset value.