CN103281704B - Based on the wireless sensor network certainty spatial portion arranging method of three-dimensional perception - Google Patents

Abstract

Based on the wireless sensor network certainty spatial portion arranging method of three-dimensional perception, be intended to study the wireless sensor network disposition algorithm realized based on three-dimensional perception model under certainty space, optimization node deployment problem is covered for network area, by three-dimensional perception model and the covering scene geometrical relationship of analysis node, realize certainty spacing wireless sensing network node Optimization deployment.In conjunction with these schemes, the deployment strategy basis realizing full-mesh realized compared with large coverage is proposed.This invention adopts sacrifice level of coverage to realize less redundancy, sensor node is inlayed in three dimensions by body-centered cubic lattic mode, the relation of analyzing communication radius and perception radius in a cubic lattice, obtaining a ratio makes node obtain higher coverage rate and low redundancy in three dimensions, now the perception spheroid of sensor node and the perception spheroid of neighbor node just in time tangent, namely now this deployment scheme is irredundant degree.

Description

Based on the wireless sensor network certainty spatial portion arranging method of three-dimensional perception

Technical field

The present invention is that one is applicable to wireless multimedia sensor network (WirelessMulti-mediaSensorNetworks, be abbreviated as WMSNs) in environment, adopt three-dimensional perception model and the covering scene geometrical relationship of the mode quantitative analysis node that ball covers and node is inlayed at body-centered cubic lattic, thus realize the Optimization deployment of the node of wireless sensor network.This technology belongs to computer network field.

Background technology

Wireless sensor network is the emerging technology of an acquisition and process information.Along with the fast development of wireless communication technology, radio sensing network (wirelesssensornetworks) presents application prospect widely in every field.Technology of wireless sensing network is the dual-use strategic high-tech typically with cross discipline character, can be widely used in the fields such as national defense and military, national security, environmental science, traffic administration, hazard prediction, health care, manufacturing industry, the development of urban informationization.The application of wireless sensor network combines the multiple advanced technologies such as sensor technology, embedding assembly technology, modern network and wireless communication technology.Wireless sense network by have radio communication, data acquisition and processing (DAP), cooperative cooperating the integrated micro transducer of function be that main body forms.Network is by the information by means of various informative transducer cooperation Real-Time Monitoring built-in in node, perception and the various environment of collection or monitoring target, by embedded system, information is processed, in multi-hop relay mode, institute's perception information is sent to user terminal by random self organizing radio network network, makes user grasp the situation of monitored area completely and make a response.

In radio sensing network, network coverage and connecting degree are large performance index.These all will realize coverage and the degree of communication of optimization by suitable node deployment.

So-called deployment issue is exactly in certain region, by suitable tactful placement sensor node to meet certain specific demand.Optimize interstitial content and Node distribution form, the sensor network resource that efficiency utilization is limited, farthest reduces network energy consumption, answers Attention question when being all node deployments.The deployment issue of wireless sensor network can be divided into covering and be connected two parts, covers the covering laying particular emphasis on node sensing scope, the connection of connection side multiple knot communication capacity.Cover and refer to that in three dimensions, certain is a bit in the perception radius of its surroundings nodes, so the information of this point just can by this sensor node monitoring acquisition, such as what information of some temperature.Be communicated with and refer to that in three dimensions, a sensor node is in the communication radius of another node around it, then this sensor node just can communicate with neighbours' sensing node, can either transmission information, time the same communication radius when each node is consistent, two nodes can intercom mutually.

The node deployment of WSN is divided into random placement and certainty to dispose usually.Deterministic network is usually based on predefined shape setting static network, and sensor network position can be uniformly distributed or adopt weighting scheme to monitor important area.As the sensor network of grille-like, sensor node is positioned on grid crosspoint, this is that one is typically uniformly distributed deterministic network, now due to symmetry and the periodically deployment of sensor network nodes, area to be monitored covering problem is just converted into the covering problem of individual node and adjacent node.Weighting predefine is disposed and is mainly utilized multiple transducer to monitor emphasis monitoring point, makes point being monitored obtain maximal cover.The feature that certainty is disposed be environment oneself know, network is relatively fixing, pre-configured node location, and according to the concrete condition determination network topology of target area, sensor node density and predetermined detection probability condition.According to the above description, the common practice that deterministic network is disposed first divides network lattice point, then carry out sensor node deployment, and my model also will obtain like this.

Deployment will consider such two aspects: cover and be communicated with.Cover and be usually defined as three classes: blanket covers, barrier covers and formula of skimming over covers.It is that the static state obtaining transducer is disposed that blanket covers object, maximizes monitoring target in coverage.Barrier covering object is that the static state in order to obtain transducer is disposed, and the destination probability that can not monitor through obstacle is minimized; It is moved by the Random Cooperation of sensor node that formula of skimming over covers, and obtains dyskinesia and covers.The information that in Sensor Network, each node needs mutual transmission node to monitor, namely be communicated with, this will arrange the communication range of sensing node in conjunction with Routing Protocol aspect, intuitively think that at communication range be also a spheroid, and in communication radius, namely Nodes then can be communicated with between node in communication ball.And certainty disposes the relation by needing to consider communication radius and perception radius, to obtain an optimized deployment scheme.

Classic algorithm has maximum average covering (MAXAVGCOV) and minimax covering algorithm (MAXMINCOV), namely according to current inserting knot situation, optimisation strategy is used to be assigned on grid by transducer, meet the coverage requirement of each grid point, and make number of sensors minimum.

Summary of the invention

Technical problem: the object of this invention is to provide a kind of wireless sensor network certainty spatial portion arranging method based on three-dimensional perception, the mode adopting ball filling and body-centered cubic lattic to inlay attempts the node deployment in 3D region space to be reached the object that height covers and height is communicated with comparatively optimized.By using this method, three-dimensional perception region the interior joint as far as possible low redundancy of disposing and high coverage rate of trying one's best can be realized, can full-mesh be realized between adjacent node on this basis.

Technical scheme: method of the present invention adopts the ball filling mode of node to complete the coverage requirement of node in 3D region, and node location forms the body-centered cubic structure in solid geometry in space, is foregoing body-centered cubic and inlays.Node has communication radius Rc and perception radius R s, communication range and the sensing range of node form spheroid in three dimensions, situation in region in the perception spheroid of node can be arrived by node perceived, and when Nodes can communicate with this neighbor node in the communication spheroid of neighbor node.

Wireless sensor network certainty spatial portion arranging method based on three-dimensional perception is included in following concrete steps:

Initial scene setting:

Step 1) configuration monitoring scene: the 3D region scene size needing monitored area is set; According to the quantity of wireless sensor node in wireless scene in the region initialization monitoring scene of monitoring of environmental,

Step 2) sensors configured node: sensor node perceived direction is omnidirectional, perception radius r s, communication radius rc;

Node deployment:

Step 3) set initial monitor scope: set sensor monitoring region as a regular domain, according to perception radius and communication radius, monitoring range is divided into space lattice, lattice is square, and its length of side corresponds to sensor node communication radius;

Step 4) sensing node deployment: in each lattice, place sensor node according to body-centered cubic lattic pattern, be and lay sensor node at the body-centered place of each lattice and eight summits place, the sensing node in these lattices will monitor whole three-dimensional environment; The sensing region of sensing node is spheroid, namely the perceived direction of these nodes is omnidirectional, tangent between perception sphere, sensing node can realize the Real-Time Monitoring to oneself peripheral region, and between node there is not redundant area in sensing region, simultaneously, the communication function that these sensing nodes have himself, the communication zone of node is a spheric region, the neighbor node of each node, in its communication zone, can ensure that node carries out the real time communication of monitoring information with other sensing nodes in its communication zone;

Space deployment is carried out according to the communication radius of sensor node and the relation of perception radius, arbitrary sensing node can communicate with its neighbours' sensing node, be 14-to be communicated with, thus realization is communicated with the height of three-dimensional environment, height covers and the space of low redundancy is disposed.

Node works:

Step 5) node monitors: start the sensing node in three-dimensional environment, start to carry out environmental monitoring, realize Monitoring Data by the communication between node and merge and converge, real time communication between node.

Beneficial effect: the wireless sensor network certainty space deployment scheme based on three-dimensional perception is first connective from the viewpoint of 3D region, it achieve the connectedness of sensing node under the environment of whole sensing region, from the viewpoint of covering, this scheme can feasible region interior nodes irredundant, coverage rate is as far as possible large, in a cubic lattice, the perception spheroid of sensor node and the perception spheroid of adjacent node just in time tangent, scheme is now break-even and coverage rate is good.From the viewpoint of actual, this programme ensure that all environmental datas of monitoring can be integrated by sensing node, and its low redundancy also can reduce the waste of sensing node simultaneously.From general plan model, it sacrifices coverage rate to realize irredundant region.

Accompanying drawing explanation

Fig. 1 is overlapping region plane graph analysis chart,

Fig. 2 covers and redundant area curve chart,

Fig. 3 covers redundant area ratio curve figure.

Embodiment

Fig. 1 is overlapping region plane graph analysis chart, when the perception radius of adjacent sensing node is greater than be two spheroids will have overlap, and as two arcuate portion in figure, overlapping region part by the perception simultaneously of two adjacent nodes, will be generation redundancy section at node duration of work.

Fig. 2 covers and redundant area curve chart, and curve draws according to formula (4)

$Y=\frac{\frac{4}{3}{X}^3-\frac{\sqrt{3}}{2}{X}^2+\frac{\sqrt{3}}{32}}{-X^3+\frac{\sqrt{3}}{2}{X}^2-\frac{\sqrt{3}}{32}}$ Formula (4)

In figure, above curve is the simplification curve of overlay area, is obtained by above formula Middle molecule part, can find out that overlay area increases gradually along with perception radius and the increase of communication radius from the cabling of this curve, but but the speed of increase little by little slow down.And that curve is below the simplification curve of redundant area, obtained by the denominator part in above formula, this curve is also increase along with perception radius and communication radius and increases to obtain, but the rate of rise of the growth curve of this curve is accelerated gradually.

Fig. 3 covers redundant area ratio curve figure, and formula covers redundant area ratio curve, through abbreviation, can make P=1/X, ask the minimum value covering redundancy ratio, be the maximum asking Q.

First suppose that the three-dimensional environment of our required monitoring is a regular three dimensions, be just similar to the environment in a room.The environment that will monitor is divided into grid one by one by us, and these grids are all geometry squares, and the space size Dingyuan due to three-dimensional environment is greater than the sizing grid that we divide, so just do not consider edge effect in the following description.Here, first the hypothetical trellis length of side is R.

After grid division, by node deployment in eight summits of square grid and position, body-centered.

In this case, the distance between node has two kinds, and one is grid length of side R, and another kind is the namely half of body diagonal length.For ensureing the connectedness between neighbor node, that is neighbor node all will in the connection spheroid of node, that just can suppose that communication radius is length larger in nodal distance, be exactly grid length of side R, I thinks that the node being positioned at eight body-centereds place around a node and six totally ten four neighbor nodes being positioned at summit place can both be communicated with node like this, is and can ensures that the 14-of three-dimensional environment interior joint is communicated with.So, first communication radius is set to rc=R here.

So on the basis that node is communicated with, covering problem will be considered afterwards.When perception radius is uncertain, first we can think that this radius is very little, all can not use overlapping region between the sensing node so on eight summits is mutual and with the node at body-centered place.When perception radius is very little time, the perception spheroid of each node does not all have the overlapping region covered, i.e. irredundant region.But its coverage rate is not high, a large amount of regions is had not to be covered to.

When perception radius is very large, we can be found by emulation, and these sensing nodes have a lot of overlapping regions, but also have some regions but not covered by sensing node.

In perception radius increase process gradually, the perception sphere of sensor node can cover overlapping with the spheroid of surrounding gradually mutually, at this time namely creates redundant area.And overlay area is also increasing gradually, but before this perception radius reaches 1/2 of communication radius, unlapped region will be there is in grid, here always, need the ratio of a searching rs/rc, coverage rate higher on realization theory and less redundancy rate.

When the perception radius of node increases gradually, by thinking overlapping with the perception spheroid of neighbor node, some redundant area will be there are like this, and in cubic lattice, still there are some regions be not capped in the perception spheroid of node, theoretically, wish that redundant area is less and overlay area is larger.These all obtain by mathematical computations below.

It is the part in the cross section of the diagonal plane to body-centered cubic lattic in Fig. 1.Body diagonal is when perception radius is greater than be two spheroids will have overlap, as shown in phantom in Figure 1.”

When $2\mathrm{rs}\≤\sqrt{3}\mathrm{rc}/2$ Time, namely $\mathrm{rs}/\mathrm{rc}\≤\sqrt{3}/4$ The volume then covered $Vf1=2*\left(4{\mathrm{\πrs}}^3\right)=\frac{8{\mathrm{\πrs}}^3}{3}.$

Separately consider that whole region covers by perception spheroid completely, and redundant area increases gradually when rs is greater than 1/2 of rc.So do not consider that rs is greater than the situation of 1/2 of rc.

When need the volume calculating redundant area in upper figure.

By spherical crown cubature formula can obtain again, h is in the drawings so the volume of this spherical crown is $Vr=\frac{2{\mathrm{\πrs}}^3}{3}-\frac{\sqrt{3}{\mathrm{\πrs}}^{2}rc}{4}+\frac{\sqrt{3}{\mathrm{\πrc}}^3}{64}.$

So the volume of whole redundant area is:

$2Vr=\frac{4{\mathrm{\πrs}}^3}{3}-\frac{\sqrt{3}{\mathrm{\πrs}}^{2}rc}{2}+\frac{\sqrt{3}{\mathrm{\πrc}}^3}{32}$ Formula (1)

And in this 1/8 lattice redundancy volume and cover volume and be identical in whole lattice, so just simplify computational process with this little square.

Here, the volume of overlay area is:

$Vf2=\frac{1}{4}*\frac{4{\mathrm{\πrs}}^3}{3}-2Vr=-{\mathrm{\πrs}}^3+\frac{\sqrt{3}{\mathrm{\πrs}}^{2}rc}{2}-\frac{\sqrt{3}{\mathrm{\πrc}}^3}{32}$ Formula (2)

A ratio can be obtained so like this

$Y=Vr/Vf2=\frac{\frac{4{\mathrm{\πrs}}^3}{3}-\frac{\sqrt{3}{\mathrm{\πrs}}^{2}rc}{2}+\frac{\sqrt{3}{\mathrm{\πrc}}^3}{32}}{-{\mathrm{\πrs}}^3+\frac{\sqrt{3}{\mathrm{\πrs}}^{2}rc}{2}-\frac{\sqrt{3}{\mathrm{\πrc}}^3}{32}}$ Formula (3)

Make rs/rc=X, then

$Y=\frac{\frac{4}{3}{X}^3-\frac{\sqrt{3}}{2}{X}^2+\frac{\sqrt{3}}{32}}{-X^3+\frac{\sqrt{3}}{2}{X}^2-\frac{\sqrt{3}}{32}}$ Formula (4)

Object is the minimum value of trying to achieve Y

Order $M=\frac{4}{3}{X}^3-\frac{\sqrt{3}}{2}{X}^2+\frac{\sqrt{3}}{32}$

$N=-X^3+\frac{\sqrt{3}}{2}{X}^2-\frac{\sqrt{3}}{32}$

$Y=\frac{1}{3}*\[\frac{1}{-1+\frac{\sqrt{3}}{2X}-\frac{\sqrt{3}}{32X^3}}\]-1$ Formula (5)

Now the minimum value of Y is converted into and asks maximum

Make P=1/X, $Q=-1+\frac{\sqrt{3}}{2X}-\frac{\sqrt{3}}{32X^3}.$

Abscissa is the ratio of perception radius and communication radius, by analysis above can know its value ( 1/2) between.Simulation result is as figure below (Fig. 2):

In upper figure, above curve be the simplification curve of overlay area, can find out that overlay area increases gradually along with the increase of perception radius and communication radius from the cabling of this curve, but but the speed increased little by little slow down.

And that curve is below the simplification curve of redundant area, this curve is also increase along with perception radius and communication radius and increases to obtain, but the rate of rise of the growth curve of this curve is accelerated gradually.

3rd the simulation experiment result following (P scope is (2,2.31)) is as Fig. 3:

Can find out that maximum obtains close to end points at curve from curve above.The maximum of this curve can be calculated by such:

The principle of being drawn by multinomial, value 3100 numerical value are total between 2 to 2.31, maximum is had when numerical value is 3048 values in the value of Q array, remain on afterwards about maximum always, so think that the value at 3048 value places is 2+0.0001*3048=2.3048, namely obtain optimization deployment model at this value place.

Namely as rs/rc=0.434, obtain the optimum model disposed.

Now can obtain from above-mentioned simulation result, when obtaining optimization deployment, the sensing region (spheroid) at cubic lattice body-centered place is tangent with the sensing region at eight summits place.Under this deployment scenario, no longer will there is redundant area in deployment region, and the ratio of overlay area and redundant area reaches minimum value in theory.

Now in a body centred lattice,

The volume of overlay area is irredundant region.

Coverage rate is $\mathrm{\η}=Vf/V=\frac{2\×\frac{4}{3}{\mathrm{\πrs}}^3}{{\mathrm{rc}}^3}=\frac{\frac{8}{3}\mathrm{\π}{(\sqrt{3}rc/4)}^3}{{\mathrm{rc}}^3}=\frac{\frac{\sqrt{3}}{8}{\mathrm{\πrc}}^3}{{\mathrm{rc}}^3}=\frac{\sqrt{3}}{8}\mathrm{\π}\≈0.68$

Radio sensing network certainty spatial portion arranging method thought based on three-dimensional perception adopts the ball filling mode of node to complete the coverage requirement of node in 3D region, node location forms the body-centered cubic structure in solid geometry in space, is foregoing body-centered cubic and inlays.Node has communication radius Rc and perception radius R s, communication range and the sensing range of node form spheroid in three dimensions, situation in region in the perception spheroid of node can be arrived by node perceived, and when Nodes can communicate with this neighbor node in the communication spheroid of neighbor node.

First scheme carries out initial scene setting, carries out initial scene partitioning based on this programme, realizes optimizing space and disposes, specific as follows:

1. initial scene setting:

First configuration monitoring scene and sensor node: the 3D region scene size needing monitored area is set, the three-dimensional environment of monitoring required for hypothesis is here a regular three dimensions, be similar to environment like a room, owing to three-dimensional environment can be divided into grid one by one afterwards, these grids are geometry square, the sizing grid that acquiescence monitoring space divides much larger than us; According to quantity, node perceived direction (in this programme, sensing node is set to omnidirectional's perception, and its sensing region is spheroid), perception radius r s, the communication radius rc of wireless sensor node in wireless scene in the region initialization monitoring scene of monitoring of environmental.

2. node deployment:

Set initial monitor scope: set sensor monitoring region as a regular domain, according to perception radius and communication radius, monitoring range is divided into space lattice, lattice is square, its length of side is R, its length of side corresponds to sensor node communication radius, in each lattice, place sensor node according to body-centered cubic lattic pattern, be and lay sensor node at the body-centered place of each lattice and eight summits place, the sensing node in these lattices will monitor whole three-dimensional environment.

The sensing region of sensing node is spheroid, and namely the perceived direction of these nodes is omnidirectional, tangent between perception sphere, namely when perception radius is also due to the relation of the lattice length of side and sensing node communication radius, the relation of node perceived radius and communication radius is as follows now sensing node can realize the Real-Time Monitoring to oneself peripheral region, and between neighbor node, sensing region does not exist redundant area.Simultaneously, the communication function that these sensing nodes have himself, the communication zone of node is a spheric region, and the neighbor node of each node, in its communication zone, can ensure that node carries out the real time communication of monitoring information with other sensing nodes in its communication zone.

Space deployment is carried out according to the relation of the communication radius of sensor node and perception radius in this programme, arbitrary sensing node can communicate with its neighbours' sensing node, be 14-to be communicated with, thus realization is communicated with the height of three-dimensional environment, height covers and the space of low redundancy is disposed.

3. node work:

Node monitors: start the node monitors in environment, realizes Monitoring Data by the communication between node and merges and converge, real time communication between node.

Concrete steps comprise:

Initial scene setting:

Step 1) configuration monitoring scene: the 3D region scene size needing monitored area is set; According to the quantity of wireless sensor node in wireless scene in the region initialization monitoring scene of monitoring of environmental.

Step 2) sensors configured node: sensor node perceived direction (in this programme, sensing node is set to omnidirectional's perception, and its sensing region is spheroid), perception radius r s, communication radius rc.

Node deployment:

Step 3) set initial monitor scope: set sensor monitoring region as a regular domain, according to perception radius and communication radius, monitoring range is divided into space lattice, lattice is square, and its length of side corresponds to sensor node communication radius.

Step 4) sensing node deployment: in each lattice, place sensor node according to body-centered cubic lattic pattern, be and lay sensor node at the body-centered place of each lattice and eight summits place, the sensing node in these lattices will monitor whole three-dimensional environment; The sensing region of sensing node is spheroid, namely the perceived direction of these nodes is omnidirectional, tangent between perception sphere, sensing node can realize the Real-Time Monitoring to oneself peripheral region, and between node there is not redundant area in sensing region, simultaneously, the communication function that these sensing nodes have himself, the communication zone of node is a spheric region, the neighbor node of each node, in its communication zone, can ensure that node carries out the real time communication of monitoring information with other sensing nodes in its communication zone;

Space deployment is carried out according to the relation of the communication radius of sensor node and perception radius in this programme, arbitrary sensing node can communicate with its neighbours' sensing node, be 14-to be communicated with, thus realization is communicated with the height of three-dimensional environment, height covers and the space of low redundancy is disposed.

Node works:

Step 5) node monitors: start the node monitors in environment, realize Monitoring Data by the communication between node and merge and converge, real time communication between node.

Claims (1)

1., based on a wireless sensor network certainty spatial portion arranging method for three-dimensional perception, it is characterized in that the method is included in following concrete steps:

initial scene setting:

Step 1) configuration monitoring scene: the 3D region scene size needing monitored area is set; According to the quantity of wireless sensor node in wireless scene in the region initialization monitoring scene of monitoring of environmental,

Step 2) sensors configured node: sensor node perceived direction is omnidirectional, perception radius r s, communication radius rc;

node deployment:

Step 3) sets initial monitor scope: set sensor monitoring region as a regular domain, according to perception radius and communication radius, monitoring range is divided into space lattice, lattice is square, and its length of side corresponds to sensor node communication radius;

Step 4) sensing node is disposed: in each lattice, place sensor node according to body-centered cubic lattic pattern, be and lay sensor node at the body-centered place of each lattice and eight summits place, the sensing node in these lattices will monitor whole three-dimensional environment; The sensing region of sensing node is spheroid, namely the perceived direction of these nodes is omnidirectional, tangent between perception sphere, sensing node can realize the Real-Time Monitoring to oneself peripheral region, and between node there is not redundant area in sensing region, simultaneously, the communication function that these sensing nodes have himself, the communication zone of node is a spheric region, the neighbor node of each node, in its communication zone, can ensure that node carries out the real time communication of monitoring information with other sensing nodes in its communication zone;

Space deployment is carried out according to the communication radius of sensor node and the relation of perception radius, arbitrary sensing node can communicate with its neighbours' sensing node, be 14-to be communicated with, thus realization is communicated with the height of three-dimensional environment, height covers and the space of low redundancy is disposed;

node works:

Step 5) node monitors: start the sensing node in three-dimensional environment, start to carry out environmental monitoring, realizes Monitoring Data by the communication between node and merges and converge, real time communication between node.