CN106358209A - Surface covering method of wireless sensor network based on Delaunay tetrahedron - Google Patents

Abstract

The invention discloses a surface covering method of a wireless sensor network based on a Delaunay tetrahedron, and belongs to the technical field of node deployment of wireless sensors. The method comprises the following steps: firstly using a Delaunay algorithm to discretize a target region, establishing a Delaunay triangulation network, then establishing a Voronoi diagram based on the Delaunay triangulation network, using the excentre of each Voronoi unit as a candidate position of the wireless sensor, and regulating the radius of a circumscribed circle to achieve different wireless sensor deployment schemes so that the wireless sensor deployment scheme can be regulated based on different surface roughness factors; screening the candidate positions, dereplicating and deleting the candidate positions located in overlapping regions, reducing the number of the deployed wireless sensors, and obtaining an optimized deployment scheme under the conditions of ensuring the local and overall communication capacity.

Description

Wireless sensor network surface covering method based on Delaunay tetrahedron

Technical field

The present invention relates to the node deployment of wireless senser and in particular to a kind of based on delaunay Delaunay tetrahedron Wireless sensor network surface covering method.

Background technology

Wireless sensor network is defined as a kind of subclass of the AD-HOC network for the purpose of monitoring.This network typically should For be difficult to reach or danger area monitoring.Wireless sensor network main composition is node, and the main of node is appointed Business is to collect monitoring desired signal.Node location distribution is incorrect to lead to wireless sensor network to be difficult to obtain the letter of needs Number.It is critical only that of the node deployment of wireless sensor network: how to ensure in different target region reasonable distribution sensor section Point, reaches the efficient region area coverage of maximum with number of sensors as few as possible.

Currently, people are to delaunay (delaunay) network of triangle and the construction distribution of voronoi (Thiessen polygon) figure The deployment of sensor node had certain achievement, but be seldom related to regard to more real topographic features, such as, area The volume of domain block and surface roughness.Generally, it is only limited to two-dimensional space during deployment.For three dimensions, a big difficult point is exactly The step needing a discretization surface cell.In this step, the data meeting that under-represented surface discretization obtains Increase the quantity of node, thus increasing the deployment quantity of sensor.

Content of the invention

The goal of the invention of the present invention is, disclose a kind of can effective control sensor deployment quantity based on delaunay four The wireless sensor network surface covering side of face body.

The wireless sensor network surface covering method based on Delaunay tetrahedron of the present invention, comprises the following steps:

Step 1: determine the border of three-dimensional target region, target area is carried out with delaunay triangulation network subdivision, set up and include The delaunay triangulation network of multiple delaunay trianglees；

Determine the border of three-dimensional target region, in order to distribution sensor node.Blender figure is for example utilized to realize The border of three-dimensional target region determines.After border determines, using delaunay delaunay triangle, target area is divided For a series of geometric units blocks (delaunay triangle) composition, target area is carried out with delaunay triangulation network subdivision, sets up The delaunay triangulation network including multiple delaunay trianglees.

Step 2: Thiessen polygon figure (voronoi figure) is built based on the delaunay triangulation network that step 1 obtains, will The circumscribed circle center of circle of each voronoi unit of voronoi in figure is as the candidate position of wireless senser；

Step 3: search the isolated node in candidate position and delete, wherein isolated node is: if current candidate position with The spacing of all adjacent candidate position is all higher than the communication radius of wireless senser, then current candidate position is defined as isolated section Point；

Step 4: delete the candidate position of repeated space position, to improve the sensor covering quality of target area, reduce Unnecessary number of sensors.

Step 5: search the overlapping region between adjacent candidate position and delete candidate position positioned at overlapping region, obtain mesh The sensor distributing position in mark region:

Step 501: constitute candidate position set t by currently all candidate position；

Step 502: randomly choose a candidate position from set t as reference position a；

Step 603: all adjacent candidate position to reference position a, judge reference position a and each adjacent candidate position respectively Air line distance between putting whether less than the circle that is located radius and, if so, then execution step 604；Otherwise execution step 605；

Step 604: calculate the reference position a and overlapping region area between currently adjacent candidate position, and from candidate position The candidate position being located at current overlapping region area is deleted in set t；

The calculating process of overlapping region area is:

Represent currently adjacent candidate position with b, represent the circle at reference position a place and circle that candidate position b is located with c, d Cross point, uses r₀、r₁The radius of circle that reference position a, b are located respectively, the position coordinateses (x based on reference position a, b_a,y_a,z_a)、 (x_b,y_b,z_b) computed range c, according to the overlapping region area of following equation calculating reference position a candidate position b:

C=((x_a-x_b)²+(y_a-y_b)²+(z_a-z_b)²)^1/2；

$cos(\frac{1}{2}\∠cab)=\frac{r_0^2+c^2-r_1^2}{2r_{0}c}$

$cos(\frac{1}{2}\∠cba)=\frac{r_1^2+c^2-r_0^2}{2r_{1}c}$

γ=acos (∠ cba), θ=2 γ；ζ=acos (∠ cab), ρ=2 ζ；

Step 505: all adjacent candidate position of reference position a is judged to finish, then continues to select one from set t Non-selected candidate position, as reference position a, continues executing with step 502, until having traveled through all candidate positions in set t Put；

Step 506: obtain the sensor distributing position of target area based on all candidate position of current collection t.

In sum, due to employing technique scheme, the invention has the beneficial effects as follows: the present invention initially with Delaunay algorithm carries out discrete region to target area, sets up the delaunay triangulation network, then builds voronoi based on it Figure, using the unfaithful intention of each voronoi unit as wireless senser candidate position, by adjust circumscribed circle radius can be real Existing different radio sensor deployment scheme, thus can be based on different earth's surface degree of roughness factor adjustment wireless senser deployment Scheme；And candidate position carried out screen, duplicate removal and delete the candidate position being located at overlapping region, reduce the wireless biography disposed The quantity of sensor, under conditions of guaranteeing local and integrated communication ability, obtains the deployment scheme optimizing.Brief description

Fig. 1 is Plain coverage test schematic diagram.

Fig. 2 is plateau coverage test schematic diagram.

Fig. 3 is mountain region coverage test schematic diagram.

Fig. 4 is Plain communication test schematic diagram.

Fig. 5 is plateau communication test schematic diagram.

Fig. 6 is mountain region communication test schematic diagram.

Specific embodiment

For making the object, technical solutions and advantages of the present invention clearer, with reference to embodiment and accompanying drawing, to this Bright it is described in further detail.

The inventive method is used for the wireless senser portion of the target area of different terrain (as Plain, plateau and mountain region etc.) Administration, and test checking directly perceived, effective is carried out on matlab, to verify the effect of its deployment.For Plain, plateau and mountain region Can be used for the practical uses such as forest fire detection etc. the wireless senser deployment of different terrain.

Setting target area is in 200 × 200m²Left and right.Fig. 1 is the target area test chart (4022.23m in Plain²), Fig. 2 Target area test chart (4080.24m for plateau²), Fig. 3 is the target area test chart (4405.92m in mountain region²).Model takes Value take into account mountain peak and mountain valley.

Carried out using the wireless sensor network surface covering method of the present invention in the target area to above-mentioned different terrain After wireless senser deployment, obtain following result:

Plain topography uses 26 wireless sensers, and each monitoring range is 295 ± 56 meters, total coverage rate 100% (4022.23m²)；

Plateau landform uses 20 wireless sensers, and each monitoring range is 335 ± 20.7 meters, total coverage rate 98.2% (4006.74m²)；

Mountain region uses 62 wireless sensers, and each monitoring range is 180 ± 4.5 meters, total coverage rate 91.01% (4009.65m²).

Fig. 4, Fig. 5, Fig. 6 have gone out the nothing in Plain, plateau and mountain region by the delaunay triangulation network and three-dimensional voronoi icon The distribution schematic diagram of line sensor node.In checking local and global communication aspect of performance, can be using based on shortest path Dijkstra algorithm is tested to different terrain.Result draws, Plain, plateau, three kinds of mountain region landform are distributed in global communication On be respectively necessary for 18 wireless sensor nodes, 8 wireless sensor nodes and 42 wireless sensor nodes.Local communication with The minimum node number of global communication and distance are limit, are realized by dijkstra algorithm.Therefore the present invention guarantee local and whole The deployment scheme of optimization under conditions of body communication ability, can be obtained based on a number of wireless senser.

Claims (1)

1. the wireless sensor network surface covering method based on Delaunay tetrahedron is it is characterised in that comprise the following steps:

Step 1: determine the border of three-dimensional target region, target area is carried out with delaunay triangulation network subdivision, foundation includes multiple The delaunay triangulation network of delaunay triangle；

Step 2: the delaunay triangulation network being obtained based on step 1 builds Thiessen polygon figure, by Thiessen polygon in figure each The circumscribed circle center of circle of Thiessen polygon unit is as the candidate position of wireless senser；

Step 3: search the isolated node in candidate position and delete, wherein isolated node is: if current candidate position with all The spacing of adjacent candidate position is all higher than the communication radius of wireless senser, then current candidate position is defined as isolated node；

Step 4: delete the candidate position of repeated space position；

Step 5: search the overlapping region between adjacent candidate position and delete candidate position positioned at overlapping region, obtain target area The sensor distributing position in domain:

Step 501: constitute candidate position set t by currently all candidate position；

Step 502: randomly choose a candidate position from set t as reference position a；

Step 503: all adjacent candidate position to reference position a, judge respectively reference position a and each adjacent candidate position it Between distance whether less than the circle that is located radius and, if so, then execution step 604；Otherwise execution step 605；

Step 504: calculate the reference position a and overlapping region area between currently adjacent candidate position, and from candidate position set t The middle candidate position deleted positioned at current overlapping region area；

The calculating process of overlapping region area is:

Represent currently adjacent candidate position with b, represent intersecting of reference position a circle being located and circle that candidate position b is located with c, d Point, uses r₀、r₁The radius of circle that reference position a, b are located respectively, the position coordinateses (x based on reference position a, b_a,y_a,z_a)、(x_b, y_b,z_b) calculate apart from c between a and b, according to the overlapping region area of following equation calculating reference position a candidate position b:

(this formula needs)

$cos(\frac{1}{2}\∠cab)=\frac{r_0^2+c^2-r_1^2}{2r_{0}c}$

$cos(\frac{1}{2}\∠cba)=\frac{r_1^2+c^2-r_0^2}{2r_{1}c}$

γ=a cos (∠ cba), θ=2 γ;ζ=a cos (∠ cab), ρ=2 ζ；

Step 505: all adjacent candidate position of reference position a is judged to finish, then continue from set t selection one not by The candidate position selecting, as reference position a, continues executing with step 502, until having traveled through all candidate position in set t；

Step 506: obtain the sensor distributing position of target area based on all candidate position of current collection t.