CN101765095B - Tracking method for wireless sensor network moving target based on mixed cluster - Google Patents

Abstract

The invention discloses a moving target tracking method of a wireless sensor network based on a mixed cluster. The sensor network is divided into non-overlapping static cluster sets, and the boundary nodes and boundary areas of each static cluster are judged according to the relative positions between nodes; when the target enters the network and is not detected by any boundary nodes, the static cluster is responsible for moving target tracking; when When the target moves to the border area and is detected by the border node, a new dynamic cluster is triggered in real time to manage the accurate positioning and dynamic tracking of the target. As the target moves, the new real-time dynamic cluster will be continuously triggered and cooperate with the static cluster to achieve movement Target dynamic real-time monitoring. Different from the traditional moving target tracking method, the present invention proposes a method based on boundary node detection, which integrates the strong real-time dynamic clusters triggered on demand into the static cluster network to form a mixed cluster structure, effectively solving the target tracking boundary problem in the static cluster network, with target The advantages of low loss rate, low energy consumption, and strong scalability.

Description

A kind of tracking method for wireless sensor network moving target based on mixed cluster

Technical field

The present invention relates to a kind of tracking method for wireless sensor network moving target based on mixed cluster, belong to the wireless sensor network field.

Background technology

Wireless sensor network forms by being deployed in sensor nodes a large amount of in the monitored area, form a multihop self-organizing network by communication between node, perceptive object information in the perception that can cooperate, the acquisition and processing network's coverage area, and send to groups of users interested.Movable object tracking is that the typical case of wireless sensor network one of uses, and has widely Military Application and civilian applications prospect, such as battlefield surroundings monitoring, logistics security management, patient health monitoring and disaster emergency relief etc.Movable object tracking problem based on wireless sensor network faces a plurality of challenges: how to utilize sensor node limited in one's ability to satisfy the hi-Fix demand; How the rational management sensor network nodes is to reduce track rejection rate and prolong network lifetime.Therefore, need the method for tracking moving target of a kind of Energy Efficient of design to satisfy user and system requirements.

Present already present typical case comprises DCTC based on the method for tracking moving target of wireless sensor network, Dynamic Clustering, four kinds of ADCT and DPT.DCTC method (Dynamic convoytree-based collaboration) is (referring to W.S.Zhang and G.H.Cao.DCTC:DynamicConvoy Tree-Based Collaboration for Target Tracking in Sensor Networks.IEEETransactions on Wireless Communications, 3 (5), 1689-1701,2004.) adopt the structure collector node based on tree to detect information, the target proximity node forms one and escorts tree, node detected information with the estimating and forecasting target location during root node was responsible for collecting and is set, along with the movement of target, escort tree based on the old node of the continuous cutting of information of forecasting and add new node to save the network energy consumption.Dynamic Clustering method is (referring to W.P. bunch of leader en and J.C.Hou and L.Sha.Dynamic Clustering for AcousticTarget Tracking in Wireless Sensor Networks.IEEE Transactions on MobileComputing, 3 (3), 258-271,2004.) depend on powerful node (bunch leader), when the information strength value that detects as bunch leader surpasses critical value, bunch leader transfers active state to, and near the node the wake up target forms a Dynamic Cluster to realize information synergism between node; ADCT method (Adaptive DynamicCluster-based Tracking) is (referring to W.C.Yang and Z.Fu and J.H.Kim and M.S.Park.An Adaptive Dynamic Cluster-Based Protocol for Target Tracking in WirelessSensor Networks.LNCS, 156-167,2007.) not by means of powerful heterogeneous node, any node all might become a bunch leader; The method comprises two execution phases: bunch leader's election stage and bunch formation stages, the nearest node of distance objective is chosen as a bunch leader usually, bunch leader wakes on every side that a hop neighbor node forms a Dynamic Cluster up, and node is reported information and led to respective cluster, bunch leader's estimating and forecasting target location; Along with Suitable For Moving-goal Problems, Dynamic Cluster constantly forms and disappears.Different from top three kinds of classical ways, DPT method (Distributed Predictive Tracking) is (referring to H.Yang and B.Sikdar.A Protocol forTracking Mobile Targets using Sensor Networks.Proc.of IEEE IWSNPA, 71-81,2003.) then proposed based on static bunch target following pattern to improve extensibility and the energy efficient of method for tracking moving target, bunch leader collects member node and detects information, the estimating and forecasting target location, and the leader node at prior notice predicted position place bunch, new bunch leader woke three suitable nodes up and detects target before target arrives.

Based on the DCTC method of tree structure farthest collector node detect information, realize effective cooperation between node, prune dynamically dynamic tree and effectively save node work energy consumption along with Suitable For Moving-goal Problems simultaneously; Yet, dynamically escort tree and generate and safeguard complexity, need a large amount of node energies that consume.Dynamic Clustering and ADCT belong to pure Dynamic Cluster method.Dynamic Clustering depends on the backbone network that powerful node forms, select appropriate node to form Dynamic Cluster, and information in time sent to the base station by backbone network, energy consumption is low, real-time, yet the method realizes by means of powerful heterogeneous node, in case the track rejection phenomenon namely occurs heterogeneous node failure; In contrast, the robustness of ADCT method is high, but the generation of Dynamic Cluster and maintenance simultaneously also can lot of energies.Relatively, high based on the DPT method extensibility of static clustering architecture, need not to generate and safeguard dynamic tree, energy consumption is low, yet in static bunch fixing member's structure be unfavorable for bunch and bunch between the live collaboration of node, positioning accuracy is low, and at bunch boundary the track rejection phenomenon occurs easily.This shows that existing method for tracking moving target can only satisfy the demand of user and system in one aspect, do not consider the dynamic equilibrium relation between energy efficient, node cooperation and the real-time Transmission three; In addition, above-mentioned classical way all depends on prediction algorithm and wakes in advance respective nodes up and detect target, and therefore, the performance of prediction algorithm will greatly affect location and tracking effect, even causes the generation of track rejection phenomenon.

Summary of the invention

The objective of the invention is to overcome the deficiencies in the prior art, a kind of tracking method for wireless sensor network moving target based on mixed cluster is provided.

Tracking method for wireless sensor network moving target based on mixed cluster comprises following steps:

1) after sensor network disposition is finished, each node is by ID and the geographical location information of broadcasting self, network is divided into bunch set of not overlapping static state, and each static bunch comprises a bunch of leader and a plurality of member node, can reach by a jumping or multi-hop between bunch leader and member node;

2) each static bunch interior nodes attribute is divided into two classes, boundary node and non-boundary node, and each node determines whether boundary node and identification borderline region according to static bunch spatial division and neighbor node spatial positional information;

3) without in the monitoring mission requirements situation, node is in resting state to save energy consumption, receive bunch leader's WAKEUP data-signal bag when node after, node is converted to rapidly operating state and fulfils the target detection responsibility, when node was reported detection information, adopting based on the method that detects information strength was that each Node configuration timer delayed delivery time is to avoid data transmission collision;

4) target is shifted to boundary node and when being detected by boundary node, Dynamic Cluster is triggered immediately, Dynamic Cluster triggers forming process and comprises two execution phases: bunch leader of Dynamic Cluster chooses with Dynamic Cluster and forms, and after Dynamic Cluster forms, identifies immediately Dynamic Cluster inner boundary node;

5) different according to the network monitoring execution pattern, proposes three kinds bunches between the real-time transfer plan of tracing task: transfer Dynamic Cluster for static bunch, Dynamic Cluster is transferred static bunch and Dynamic Cluster transfer Dynamic Cluster.

Described each node determines whether that according to static bunch spatial division and neighbor node spatial positional information the boundary node step is: node be boundary node and if only if exists at least a neighbor node that belongs to any other bunches in its perception detects distance, have following logical expression:

In the formula: B _I.stateThe boundary condition of expression node, B _I.state=1 representation node is boundary node, B _I.state=0 representation node is not boundary node; l _i, l _jDifference representation node i, the geographical location information of j; r _sRepresent the unified detection distance of all nodes; N (v _i) the neighbor node collection of representation node i; CH (v _i), CH (v _j) difference representation node i, bunch leader of j.

Describedly according to static bunch spatial division and neighbor node spatial positional information identification borderline region step be: borderline region refers at least by two different static bunch zones that interior nodes covered;

Described employing based on the method that detects information strength for each Node configuration timer delayed delivery time take avoid the data transmission collision step as: the set timer rule is as follows:

${\mathrm{BT}}_i=W_{\mathrm{size}}\mathrm{\β}\sqrt{\frac{r_{\mathrm{th}}}{r_i}}+{\mathrm{\σ}}_i$

Wherein: BT _iThe timer value that the representative sensor node i will arrange; W _SizeRepresentative retreats window size; r _iThe detection signal strength value of representative sensor node i; r _ThThe representative sensor node is judged the detection signal strength critical value whether target occurs; σ _iRepresent the random time spacing value; When timer stopped, node sent real-time detection information to bunch leader, and the nodal distance target is nearer, and its detection signal strength value is larger, and it waits for that transmitting time is shorter.

Bunch leader's selecting step of described Dynamic Cluster is: choose in the boundary node that current time detects target and have the node of maximum signal as bunch leader of Dynamic Cluster, be expressed as follows:

$L_{\mathrm{dc}}(t+1)=v_i=\arg {\max }_{v_i\∈B_j\left(t\right)}\left|\right|r_i\left|\right|$

Wherein: L _Dc(t+1): bunch leader of the Dynamic Cluster that (t+1) constantly will trigger; v _iRepresentation node i; B _j(t): current t detects the boundary node collection of target constantly.

Described Dynamic Cluster forms step: the neighbor node that Dynamic Cluster bunch leader wakes up in the jumping scope forms new Dynamic Cluster.

Described identification Dynamic Cluster inner boundary node step is: Dynamic Cluster member node be the Dynamic Cluster boundary node and if only if exists at least a neighbor node that does not belong to Dynamic Cluster to detect within the distance at it, be expressed as follows:

Wherein: B _I.vstateThe boundary condition of expression node, B _I.vstate=1 representative is that node is the Dynamic Cluster boundary node, B _I.vstate=0 representation node is not the Dynamic Cluster boundary node; l _i, l _jDifference representation node i, the geographical location information of j; N (v _i) the neighbor node collection of representation node i; DC represents respectively Dynamic Cluster.

Described static state bunch is transferred a Dynamic Cluster step: can not transfer at once tracing task to Dynamic Cluster for static bunch, but after Dynamic Cluster waits for that goal verification enters borderline region, transfer tracing task to static bunch of request.

Described Dynamic Cluster is transferred static bunch step: when Dynamic Cluster confirms that target is not detected by any static state bunch boundary node, initiatively transfer tracing task to static bunch.

Described Dynamic Cluster is transferred the Dynamic Cluster step: after new Dynamic Cluster was triggered formation, current Dynamic Cluster was initiatively transferred tracing task at once to new Dynamic Cluster.

Along with the movement of target, Dynamic Cluster constantly is triggered to cooperate static bunch tracked mobile target.

The present invention is compared with existing technology, and the beneficial effect that has is:

The Dynamic Cluster thought that 1) will trigger as required incorporates in the static bunch network configuration, is specially adapted to effective tracking of moving target in the massive wireless sensor;

2) greatly improve the real-time of extensibility, manageability and the transfer of data of network based on static bunch the network architecture;

3) concept of proposition Dynamic Cluster has solved the border issue that can't cooperate in boundary bunch intermediate node;

4) concept that proposes bunch inner boundary node and borderline region need not to avoid predicated error to the adverse effect of tracking effect by means of prediction algorithm and network global knowledge to judge whether border between close bunch of target, has improved the stability of target following effect.

5) compare with conventional art, method for tracking moving target of the present invention effectively balance energy consumption and tracking accuracy, specifically, under identical constraint, this method has the energy consumption (as shown in Figure 3) of compromise; This method has maximum target detection coverage rate (as shown in Figure 4); This method has minimum track rejection rate (as shown in Figure 5); Wherein DCTC is for dynamically escorting the tree method for tracking target, and ADCT is self adaptation Dynamic Cluster method for tracking target, and DPT is the Distributed Predictive method for tracking target, and HCTT is the wireless sensor network target tracking method based on mixed cluster that the present invention proposes.

Description of drawings

Fig. 1 is that Dynamic Cluster of the present invention triggers, static bunch of transfer tracing task to Dynamic Cluster and Dynamic Cluster transferred tracing task to static bunch schematic diagram;

Fig. 2 is that Dynamic Cluster of the present invention triggers and Dynamic Cluster is transferred tracing task to the Dynamic Cluster schematic diagram;

Fig. 3 is that the energy consumption of different target tracking under different predicated errors compares;

Fig. 4 is that the monitoring coverage rate of different target tracking under different predicated errors compares;

Fig. 5 is that the track rejection rate of different target tracking under different predicated errors compares;

Fig. 6 is a kind of tracking method for wireless sensor network moving target schematic diagram based on mixed cluster.

Embodiment

Tracking method for wireless sensor network moving target based on mixed cluster comprises following steps:

1) after sensor network disposition is finished, each node is by ID and the geographical location information of broadcasting self, network is divided into bunch set of not overlapping static state, and each static bunch comprises a bunch of leader and a plurality of member node, can reach by a jumping or multi-hop between bunch leader and member node;

2) each static bunch interior nodes attribute is divided into two classes, boundary node and non-boundary node, and each node determines whether boundary node and identification borderline region according to static bunch spatial division and neighbor node spatial positional information;

3) without in the monitoring mission requirements situation, node is in resting state to save energy consumption, receive bunch leader's WAKEUP data-signal bag when node after, node is converted to rapidly operating state and fulfils the target detection responsibility, when node was reported detection information, adopting based on the method that detects information strength was that each Node configuration timer delayed delivery time is to avoid data transmission collision;

4) target is shifted to boundary node and when being detected by boundary node, Dynamic Cluster is triggered immediately, Dynamic Cluster triggers forming process and comprises two execution phases: bunch leader of Dynamic Cluster chooses with Dynamic Cluster and forms, and after Dynamic Cluster forms, identifies immediately Dynamic Cluster inner boundary node;

5) different according to the network monitoring execution pattern, proposes three kinds bunches between the real-time transfer plan of tracing task: transfer Dynamic Cluster for static bunch, Dynamic Cluster is transferred static bunch and Dynamic Cluster transfer Dynamic Cluster.

Described each node determines whether that according to static bunch spatial division and neighbor node spatial positional information the boundary node step is: node be boundary node and if only if exists at least a neighbor node that belongs to any other bunches in its perception detects distance, have following logical expression:

In the formula: B _I.stateThe boundary condition of expression node, B _I.state=1 representation node is boundary node, B _I.state=0 representation node is not boundary node; l _i, l _jDifference representation node i, the geographical location information of j; r _sRepresent the unified detection distance of all nodes; N (v _i) the neighbor node collection of representation node i; CH (v _i), CH (v _j) difference representation node i, bunch leader of j.

Describedly according to static bunch spatial division and neighbor node spatial positional information identification borderline region step be: borderline region refers at least by two different static bunch zones that interior nodes covered;

Described employing based on the method that detects information strength for each Node configuration timer delayed delivery time take avoid the data transmission collision step as: the set timer rule is as follows:

${\mathrm{BT}}_i=W_{\mathrm{size}}\mathrm{\β}\sqrt{\frac{r_{\mathrm{th}}}{r_i}}+{\mathrm{\σ}}_i$

Wherein: BT _iThe timer value that the representative sensor node i will arrange; W _SizeRepresentative retreats window size; r _iThe detection signal strength value of representative sensor node i; r _ThThe representative sensor node is judged the detection signal strength critical value whether target occurs; σ _iRepresent the random time spacing value; When timer stopped, node sent real-time detection information to bunch leader, and the nodal distance target is nearer, and its detection signal strength value is larger, and it waits for that transmitting time is shorter.

Bunch leader's selecting step of described Dynamic Cluster is: choose in the boundary node that current time detects target and have the node of maximum signal as bunch leader of Dynamic Cluster, be expressed as follows:

$L_{\mathrm{dc}}(t+1)=v_i=\arg {\max }_{v_i\∈B_j\left(t\right)}\left|\right|r_i\left|\right|$

Wherein: L _Dc(t+1): bunch leader of the Dynamic Cluster that (t+1) constantly will trigger; v _iRepresentation node i; B _j(t): current t detects the boundary node collection of target constantly.

Described Dynamic Cluster forms step: the neighbor node that Dynamic Cluster bunch leader wakes up in the jumping scope forms new Dynamic Cluster.

Described identification Dynamic Cluster inner boundary node step is: Dynamic Cluster member node be the Dynamic Cluster boundary node and if only if exists at least a neighbor node that does not belong to Dynamic Cluster to detect within the distance at it, be expressed as follows:

Wherein: B _I.vstateThe boundary condition of expression node, B _I.vstate=1 representative is that node is the Dynamic Cluster boundary node, B _I.vstate=0 representation node is not the Dynamic Cluster boundary node; l _i, l _jDifference representation node i, the geographical location information of j; N (v _i) the neighbor node collection of representation node i; DC represents respectively Dynamic Cluster.

Described static state bunch is transferred a Dynamic Cluster step: can not transfer at once tracing task to Dynamic Cluster for static bunch, but after Dynamic Cluster waits for that goal verification enters borderline region, transfer tracing task to static bunch of request.

Described Dynamic Cluster is transferred static bunch step: when Dynamic Cluster confirms that target is not detected by any static state bunch boundary node, initiatively transfer tracing task to static bunch.

Described Dynamic Cluster is transferred the Dynamic Cluster step: after new Dynamic Cluster was triggered formation, current Dynamic Cluster was initiatively transferred tracing task at once to new Dynamic Cluster.

Embodiment:

Now 1,2 and 6 explanation specific embodiments of the invention are by reference to the accompanying drawings:

1) sensor network being divided into not overlapping static state bunch set step is:

When sensor network disposition behind the monitored area, ID and geographical location information by each node broadcasts self, the sensor network that is deployed in area-of-interest is divided into a plurality of not overlapping static state bunch set, each static bunch comprises a bunch of leader and a plurality of member node, can reach by a jumping or multi-hop between bunch leader and member node.

Generally, bunch leader's energy consumption is energy consumption between balance node greater than the energy consumption of member node, strengthens system robustness, and node must be served as a bunch head by turns, and therefore, network is every to be spent one period cycle and need to carry out again sub-clustering.

2) determine whether that according to static bunch spatial division and neighbor node spatial positional information boundary node and identification borderline region step are:

Static bunch boundary node is defined as: node be boundary node and if only if exists at least one to belong to arbitrarily that the neighbor node of other bunches detects within the distance at it, have following expression:

In the formula: B _I.stateThe boundary condition of expression node, B _I.state=1 representation node is boundary node, B _I.state=0 representation node is not boundary node; l _i, l _jDifference representation node i, the geographical location information of j; r _sRepresent the unified detection distance of all nodes; N (v _i) the neighbor node collection of representation node i; CH (v _i), CH (v _j) difference representation node i, bunch leader of j.

Each node defines according to boundary node in the network, judges whether self is boundary node, if boundary node arranges state B _I.state=1, otherwise, state B is set _I.state=0.

Borderline region refers at least by two different static bunch zones that interior nodes covered

1) concrete steps of node detection and information report process are:

A. after target entered network, the working node of target proximity can detect target and report detection signal strength r _iTo bunch leader, a bunch leader judge draw target oneself bunch in, and in waking up bunch all nodes to detect target.

B. synchronization may have a plurality of nodes to detect simultaneously target, and information need to be reported to a bunch leader.For avoiding data collision, each node that detects target arranges a timer according to detection signal strength self, until timer is when stopping, node sends detection information to a bunch leader.

The set timer rule is as follows:

${\mathrm{BT}}_i=W_{\mathrm{size}}\mathrm{\β}\sqrt{\frac{r_{\mathrm{th}}}{r_i}}+{\mathrm{\σ}}_i$

Wherein: BT _iThe timer value that the representative sensor node i will arrange; W _SizeRepresentative retreats window size; r _iThe signal strength values that the representative sensor node i detects; r _ThThe representative sensor node is judged the signal strength signal intensity critical value whether target occurs; σ _iRepresent the random time spacing value, send conflict to evade identical any two node datas of input intensity.

Based on the setting of this timer rule, the node that detection signal strength is larger (it is larger to be generally the information quality entropy) the report time is more not only avoided data collision, simultaneously so that obtaining information is more valuable.

A. after a bunch leader receives node detection data, adopt the location algorithm estimating target position (x such as barycenter location, maximal possibility estimation _Est, y _Est).

2) step of Dynamic Cluster trigger process and boundary node identification is:

A. along with Suitable For Moving-goal Problems, the node that detects target is constantly reported detection information to bunch leader.When a bunch leader received that boundary node detects information, bunch leader's judgement drew target near also entering borderline region, needs to trigger the Dynamic Cluster process.Bunch leader at first selects current time to detect in the boundary node of target to have the node of maximum signal as bunch leader of Dynamic Cluster, and sends the DCLEADER data packets to this node.

Dynamic Cluster bunch leader's selection rule is expressed as follows:

$L_{\mathrm{dc}}(t+1)=v_i=\arg {\max }_{v_i\∈B_j\left(t\right)}\left|\right|r_i\left|\right|$

Wherein: L _Dc(t+1): bunch leader of the Dynamic Cluster that (t+1) constantly will trigger; v _iRepresentation node i; B _j(t): current t detects the boundary node collection of target constantly.

B. after this node receives DCLEADER information, oneself state is set is bunch leader, and broadcasting RECRUIT packets of information.Each receives the node answer CONFIRM packets of information of RECRUIT packets of information to bunch leader, and sets up a new node state table, preserves Dynamic Cluster information.After bunch leader receives the CONFIRM packets of information of node, store the state information of member node, Dynamic Cluster forms.

C. after Dynamic Cluster formed, each Dynamic Cluster member node judged whether self is the Dynamic Cluster boundary node.The Dynamic Cluster boundary node is defined as: Dynamic Cluster member node be the Dynamic Cluster boundary node and if only if exists at least a neighbor node that does not belong to Dynamic Cluster to detect within the distance at it, have following logical expression:

Wherein: B _I.vstateThe boundary condition of expression node, B _I.vstate=1 representative is that node is the Dynamic Cluster boundary node, B _I.vstate=0 representation node is not the Dynamic Cluster boundary node; l _i, l _jDifference representation node i, the geographical location information of j; N (v _i) the neighbor node collection of representation node i; DC represents Dynamic Cluster.

D. the Dynamic Cluster member node defines according to boundary node, judges that whether self is boundary node, if be boundary node, arranges state B _I.vstate=1, otherwise, state B is set _I.vstate=0.

3) tracing task is transferred step and is bunch:

Three kinds of transfer situations of tracing task between introducing bunch in conjunction with Fig. 1 and Fig. 2.

A. static bunch of transfer tracing task is as follows to the concrete steps of Dynamic Cluster:

A. as shown in Figure 1, work at present bunch is static bunch A, and when target was moved to a some b by an a, boundary node detected target, the Dynamic Cluster D1 formation that is triggered.At this moment, do not transfer at once tracing task to Dynamic Cluster, but wait for when goal verification enters borderline region and just transferring for static bunch.When bunch leader of D1 received that node is reported information, goal verification entered borderline region.

B. bunch leader (D1) transfers to bunch leader (A) transmission REQUEST bag request task of static bunch, after receiving the REQUEST bag, bunch leader (A) sends the AGREE packets of information and agrees that the leader transfers, and sends historical target estimated value to a bunch leader (D1);

C. after receiving the AGREE bag, a bunch leader (D1) at first broadcasts the WAKEUP bag and wakes this bunch member node up, then replys SUCCESS and wraps to a bunch leader (A);

D. after receiving the SUCCESS bag, bunch leader (A) broadcasting DISMISS bag, any member node that does not belong to simultaneously the static state bunch A of Dynamic Cluster D1 receives that entering resting state after DISMISS wraps saves energy consumption.

B. Dynamic Cluster transfer tracing task is as follows to static bunch concrete steps:

A. as shown in Figure 1, work at present bunch is Dynamic Cluster D1, when target is moved to a some d by a c, if report detection information without any a static state bunch boundary node, triggers Dynamic Cluster and transfers tracing task to static bunch.

B. bunch leader (D1) sends the HANDOFF information notification packet to a bunch leader (D) of static bunch, and sends historical target estimated value to a bunch leader (D);

C. after receiving the HANDOFF packets of information, a bunch leader (D) at first broadcasts the WAKEUP bag and wakes this bunch member node up, then replys SUCCESS and wraps to a bunch leader (D1);

D. after receiving the SUCCESS bag, bunch leader (D1) broadcasting DISMISS bag, the knot removal Dynamic Cluster information list of any DISMISS of receiving bag withdraws from Dynamic Cluster.

C. Dynamic Cluster is transferred tracing task to Dynamic Cluster:

A. as shown in Figure 2, when prevariety is Dynamic Cluster D2, when target by a b when a c enters static bunch of D, D2 can not transfer tracing task to static bunch, when the Dynamic Cluster boundary node detects target, the Dynamic Cluster D3 formation that is triggered.Bunch leader (D2) sends a HANDOFF information notification packet to a bunch leader (D3), and sends historical target estimated value to a bunch leader (D3);

B. after receiving the HANDOFF packets of information, a bunch leader (D3) at first broadcasts the WAKEUP bag and wakes this bunch member node up, then replys SUCCESS and wraps to a bunch leader (D2);

After receiving the SUCCESS bag, bunch leader (D2) broadcasting DISMISS bag, the knot removal Dynamic Cluster information list of any DISMISS of receiving bag withdraws from Dynamic Cluster D2.

Above-mentioned specific embodiment is used for explaining the present invention, rather than limits the invention, and in the protection range of spirit of the present invention and claim, to not inventing any modification and the change of making, all falls into protection scope of the present invention.

Claims (9)

1. a wireless sensor network mobile target tracking method based on mixed clusters, is characterized in that comprising the steps: 1) After the deployment of the sensor network is completed, each node divides the network into non-overlapping static cluster sets by broadcasting its own ID and geographic location information. Each static cluster includes a cluster leader and multiple member nodes. Cluster leaders and members Nodes are reachable through one or more hops; 2) The attributes of nodes in each static cluster are divided into two categories, boundary nodes and non-boundary nodes. Each node judges whether it is a boundary node and identifies the boundary area according to the static cluster space division and the spatial location information of neighbor nodes; 3) When there is no monitoring task requirement, the node is in a dormant state to save energy consumption. When the node receives the WAKEUP data signal packet from the cluster leader, the node quickly switches to the working state to perform the target detection duty. When the node reports the detection information, it uses Based on the method of detecting information strength, a timer is set for each node to delay the sending time to avoid data sending conflicts; 4) When the target moves to the boundary node and is detected by the boundary node, the dynamic cluster is triggered immediately. The dynamic cluster trigger formation process includes two execution stages: the cluster leader selection of the dynamic cluster and the formation of the dynamic cluster. After the dynamic cluster is formed, it is identified immediately. Dynamic cluster boundary nodes; 5) According to the different execution modes of network monitoring, three inter-cluster tracking task real-time handover schemes are proposed: static cluster handover to dynamic cluster, dynamic cluster handover to static cluster and dynamic cluster handover to dynamic cluster. 2. a kind of wireless sensor network mobile target tracking method based on mixed cluster as claimed in claim 1, is characterized in that: each described node judges whether to be boundary node step according to static cluster space division and neighbor node space position information: : A node is a border node if and only if there is at least one neighbor node belonging to any other cluster within its perceptual detection distance, with the following logical expression:

In the formula: B _i.state indicates the boundary state of the node, B _i.state =1 indicates that the node is a boundary node, B _i.state =0 indicates that the node is not a boundary node; l _i and l _j respectively represent the geographic Position information; r _s represents the uniform detection distance of all nodes; N(v _i ) represents the neighbor node set of node i; CH(v _i ), CH(v _j ) represent the cluster leaders of node i and j respectively. 3. a kind of wireless sensor network mobile target tracking method based on mixed cluster as claimed in claim 1, it is characterized in that: described according to static cluster space division and neighboring node spatial position information identification boundary area step is: boundary area is Refers to the area covered by at least two different static cluster nodes. 4. a kind of wireless sensor network mobile target tracking method based on mixed cluster as claimed in claim 1, is characterized in that: the cluster leader selection step of described dynamic cluster is: select the border node that detects target at present moment and has The node with the maximum signal strength acts as the cluster leader of the dynamic cluster, expressed as follows: ${\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; dc</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; arg</span>}\mathrm{<span\; class="notranslate">\; max</span>}}_{{\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; \&Element;</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; |</span>{\mathrm{<span\; class="notranslate">\; r</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; |</span>$ Among them: L _dc (t+1): cluster leader of the dynamic cluster to be triggered at (t+1) moment; r _i represents the detection signal strength value of sensor node i, v _i represents node i; B _j (t): current The boundary node set of the target detected at time t. 5. a kind of wireless sensor network moving object tracking method based on mixed cluster as claimed in claim 1, is characterized in that: described dynamic cluster formation step is: dynamic cluster cluster leader wakes up the neighbor node in the range of one hop to form a new of dynamic clusters. 6. a kind of wireless sensor network mobile target tracking method based on mixed cluster as claimed in claim 1, is characterized in that: described identification dynamic cluster internal boundary node step is: a dynamic cluster member node is a dynamic cluster boundary node when And only if there is at least one neighbor node that does not belong to the dynamic cluster within its detection distance, expressed as follows:

Among them: B _i.vstate represents the boundary state of the node, B _i.vstate = 1 represents the node is a dynamic cluster boundary node, B _i.vstate = 0 represents the node is not a dynamic cluster boundary node; l _i , l _j represent node i respectively , the geographic location information of j; N(v _i ) represents the neighbor node set of node i, r _s represents the node detection distance; DC represents the dynamic cluster. 7. A kind of wireless sensor network mobile target tracking method based on mixed cluster as claimed in claim 1, is characterized in that: described static cluster handover dynamic cluster step is: static cluster will not hand over tracking task to dynamic cluster immediately, Instead, the dynamic cluster waits for the target to confirm that it has entered the boundary area, and then requests the static cluster to hand over the tracking task. 8. A kind of wireless sensor network mobile object tracking method based on mixed cluster as claimed in claim 1, it is characterized in that: described dynamic cluster handover static cluster step is: dynamic cluster confirms that target is not detected by any static cluster boundary node At that time, actively hand over the tracking task to the static cluster. 9. A kind of wireless sensor network mobile object tracking method based on mixed cluster as claimed in claim 1, it is characterized in that: described dynamic cluster handover dynamic cluster step is: after new dynamic cluster is triggered to form, current dynamic cluster The cluster immediately actively hands over the tracking task to the new dynamic cluster.

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