CN104320822A - Method for positioning boundary region of poisonous gas in industrial factory district - Google Patents

Abstract

The invention discloses a method for locating a toxic gas boundary area in an industrial factory area, which includes the following steps: (1) distinguishing all nodes inside the toxic gas and all nodes outside the toxic gas; (2) each sensor node hops to itself All neighbor nodes broadcast messages; (3) Inner boundary node location and inner boundary location; (4) Outer boundary node location and outer boundary location; (5) Border Face area location; (6) Border area location. The invention can not only locate the inner and outer boundary nodes of the toxic gas, but also accurately locate the area of the boundary area where the toxic gas is located.

Description

Location method of toxic gas boundary area in industrial factory area

technical field

The invention belongs to the field of industrial wireless sensor networks, and specifically relates to a method for locating a toxic gas boundary area in an industrial factory area, which locates and reports the toxic gas boundary area, and improves the positioning accuracy of the toxic gas boundary area.

Background technique

In recent years, with the development and maturity of sensor manufacturing technology and wireless network communication technology, the use of miniaturized, highly integrated and multi-functional sensor nodes has become a reality. In the production process of large petrochemical enterprises, various Various toxic chemical gases, when these toxic gases reach a certain concentration, will threaten the life safety of front-line staff and direct major economic losses in units of 100 million yuan, so the detection and location of leaked toxic gases are crucial important. Moreover, gas does not have a clear boundary like liquid. The most important problem that needs to be solved for gas is not only the accurate detection of gas, but also the use of sensor networks to determine the approximate boundary area of the gas, and a series of algorithms to improve the accuracy of the boundary area.

At present, the relevant research literature on boundary positioning at home and abroad is as follows:

In 2008, Chang et al. proposed a CODA strategy that allows each sensor node to detect and track moving targets within the sensing range in "CODA: A Continuous Objet Detection and Tracking Algorithm for Wireless Ad Hoc Sensor Networks", proposing the boundaries of continuous targets The sensor is determined by the cluster head in the static cluster, rather than by multiple sensors after a large amount of data exchange, which can reduce communication overhead and energy consumption. However, the cost of cluster structure and cluster maintenance in the early stage of CODA algorithm is very high, and it is an algorithm based on convex hull, which is not particularly accurate and reliable when detecting concave continuous targets.

In 2011, Luan et al. proposed the RCOT algorithm for continuous object tracking in "Continuous Object Tracing in WirelessSensor Networks". RCOT is the first theoretical algorithm that uses a ring network structure to detect and monitor the boundaries of continuous objects, and uses compression Report the size of the message to reduce power consumption. But he reports the inner boundary nodes of the toxic gas, not the region crossed by the boundary of the toxic gas.

In 2012, Kim et al. proposed in "Efficient Continuous Object Tracking with Virtual Grid in Wireless Sensor Networks" to detect, track and locate gas targets using a scheme similar to pixel distribution imaging in TV dramas. Although the area of the region crossed by the toxic gas boundary is reported, the virtual grid-based network model assumed by this method is too idealized. In many practical applications, such as in large petrochemical plants, the grid-based network layout is difficult Realization, and the density of the virtual grid setting in this scheme directly affects the accuracy of gas boundary detection.

Thus, the prevailing questions in the current literature on boundary localization are:

Most of the continuous object localization algorithms only detect the inner boundary nodes, rather than the area where the target object is located, which is meaningless for gas. Or some models are too idealized to be realized in reality.

Contents of the invention

The purpose of the present invention is to solve the deficiencies of the current positioning algorithm for toxic gas in large industrial factory areas. The method of the present invention can not only detect the toxic gas, but also accurately locate the boundary area where the toxic gas is located .

In order to achieve the above purpose, the present invention provides a method for locating the toxic gas boundary area based on a planarization algorithm. Since the wireless sensor nodes are randomly distributed in the factory area, in order to allow each node to be effectively connected and energy-efficient, the present invention uses a planarization algorithm to connect the entire network.

Technical scheme of the present invention is as follows:

A kind of localization method of poisonous gas boundary area in industrial factory area, comprises the steps:

(1), each sensor node detects whether it senses toxic gas, and distinguishes all nodes in the toxic gas and all nodes outside the toxic gas;

(2), each sensor node broadcasts a message to all neighbor nodes in its own hop, and the information data broadcast by the node includes at least three kinds: the ID information of the node, the coordinate information of the node and the information of whether the node senses toxic gas;

(3), inner boundary node positioning and inner boundary positioning

In all the nodes in the toxic gas, according to the information of whether the toxic gas is sensed in the information received from the neighbor nodes within the one-hop communication range, it is judged that:

3a. Assuming that all the neighbor nodes of a node sense the poisonous gas, then the node is a common poisonous gas internal node, which is eliminated in the calculation;

3b. Assuming that at least one of the information received by a node from all neighbor nodes has not sensed toxic gas, then this node is an inner boundary node, and records the corresponding ID information and coordinate information;

3c. According to the ID information and coordinate information recorded in step 3b in the boundary node positioning, the inner boundary nodes form a unique circular path, which is called the inner boundary;

(4), outer boundary node positioning and outer boundary positioning

Among all the nodes outside the toxic gas, according to whether the poisonous gas is sensed in the information packet received from the neighbor node within the one-hop communication range, it is judged that:

4a. Assuming that all the neighbor nodes of a node have not sensed the toxic gas, then the node is an ordinary node outside the toxic gas, which is excluded in the calculation;

4b. Assuming that at least one of the information received by a node from all neighbor nodes has sensed toxic gas, then this node is an outer boundary node, and records the corresponding ID information and coordinate information;

4c. According to the ID information and coordinate information recorded in step 4b of the boundary node positioning, and the global routing information connected to the entire network nodes stored in the base station, the outer boundary nodes form a unique ring path, called the outer boundary;

(5), Boundary Face area positioning

According to the node information of the inner and outer borders and the global routing information of the entire network nodes stored in the base station, two adjacent and connected inner border nodes and their corresponding outer border nodes find the shortest path connected to each other through the global routing information;

Assuming that both inner boundary nodes have only one outer boundary node, then the shortest path connecting the outer boundary nodes is found through the global routing information, and then the area surrounded by the connection with the inner and outer boundary nodes is the boundary Face area area;

Assuming that two inner border nodes have more than two outer border nodes, then through global routing information calculation, there is this inner border node in the shortest path for an outer border node of one inner border node to find the outer border node of another inner border node. other outer border nodes of the border node, then replace the previous outer border node with the outer border node in the path; and so on, if the shortest path connecting two outer border nodes does not contain other outer border nodes, then the shortest path and inner and outer border nodes The area enclosed by the boundary nodes is the boundary Face area area;

(6), boundary area positioning

According to the information of the determined inner boundary and outer boundary, the boundary area is determined, and the middle area enclosed by the inner boundary and the outer boundary is the toxic gas boundary area.

The method of forming a unique circular path for the inner boundary nodes in the above step 3c is as follows:

Each inner boundary node must be connected and only connected to other two inner boundary nodes. According to the known coordinate information, it is assumed that the coordinates of node I are (χ _i , y _i ), and the coordinates of other nodes are J(χ _j , y _j ), calculate the distance between node I and other nodes Take the two nodes with the smallest distance to connect, and then take any direction and so on for recursive selection until returning to the first node, so that all inner boundary nodes form a unique ring, called the inner boundary.

The method for forming a unique circular path for the inner boundary nodes in step 4c above is as follows:

Assuming that two adjacent outer border nodes need to be connected, according to the ID information, coordinate information and the global routing information through the base station, first judge whether they are within the communication range of the sensor node’s one-hop neighbor, if yes, connect directly, if not, then Then judge whether the shortest path connecting two nodes passes through the inner boundary node, if so, remove this path, select the shortest path except through the inner boundary node, if not, select it as the connection path, and so on to make all the outer boundary nodes A unique circular path is formed, called the outer boundary.

The invention can not only accurately locate the inner and outer boundary nodes of the area where the toxic gas is located when the gas leaks in the industrial factory area, but also accurately locate the area of the boundary area where the toxic gas is located.

Description of drawings

Fig. 1 is the flow chart analysis schematic diagram of the present invention;

Fig. 2 is a schematic diagram of system features of the present invention;

Figure 3 is a schematic diagram of using Gas information to detect and distinguish internal and external boundary nodes;

Fig. 4 is a schematic diagram of determining the inner boundary by using the inner boundary node ID information and coordinate information;

Fig. 5 is a schematic diagram of determining the outer boundary by using outer boundary node ID information, coordinate information and global routing information;

Fig. 6 is a schematic diagram of determining the boundary Face area area by using inner and outer boundary nodes;

Fig. 7 is a schematic diagram of determining the toxic gas boundary area based on the inner boundary and the outer boundary;

● in the figure indicates the node that senses the gas; ○ indicates the node that does not sense the gas; Indicates the inner and outer boundaries; represents a gas mass.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings. The following examples are only used to illustrate the technical solution of the present invention more clearly, but not to limit the protection scope of the present invention.

As shown in Figure 1, once a toxic gas is found, the sensor nodes are first screened to judge and distinguish all nodes inside and outside the gas; then all nodes inside the gas are screened to select inner boundary nodes; all nodes outside the gas The nodes are screened to select the outer boundary nodes; then the inner and outer boundaries are formed according to the inner and outer boundary nodes, and then the boundary area of the toxic gas is determined according to the inner and outer boundaries.

As shown in Figure 2, it is an area of toxic gas and sensor nodes A to U randomly arranged in the area. Each node has its own ID, coordinates and other information. The nodes within the communication range of one hop broadcast each other. It is possible to know the information of all nodes in the neighbors of a node, combined with the information of the node itself, it can be judged that nodes A to K are all the outer boundary nodes of the gas, and nodes L to S are all the inner boundary nodes of the gas, and because the node T The one-hop neighbors of node U are all nodes that sense gas, so they are not inner boundary nodes; then determine the inner and outer boundaries according to the ID and coordinate information of the boundary nodes, and then determine the boundary area according to the inner and outer boundaries.

As shown in Figure 3, A-V nodes are arranged in the area. It is easy to see from the figure that the nodes M-V sense the toxic gas, so they are internal nodes of the gas, and then send data packets by broadcasting between one-hop neighbor nodes , such as node O, it sends data to nodes H, I, J, V, P, and learns that nodes H, I, J have not sensed poisonous gas, which is consistent with at least one node in one-hop neighbor nodes not sensing poisonous gas condition, so node O is an inner boundary node. As for node V, its one-hop neighbor nodes O, P, W, R, U, and N all sense poisonous gas, which does not meet the conditions of inner boundary nodes, so it is only a node inside the gas, and the node of this node will be eliminated in the subsequent calculations. information. By analogy, it can be obtained that nodes M, N, P, Q, R, S, and T are also inner boundary nodes, and record their information. Nodes A-L do not sense toxic gas, so they are gas-external nodes, and then send data by broadcasting between one-hop neighbor nodes of the node, such as node C, which sends data to nodes B, D, E, R, and S, and obtains It is known that nodes R and S have sensed poisonous gas, which meets the condition that at least one node senses poisonous gas in one-hop neighbor nodes, so node C is an outer boundary node. As for node D, its one-hop neighbor nodes B, C, and E have not sensed toxic gas, which does not meet the conditions of an outer boundary node, so node D is only an outer node of gas. By analogy, we can get that nodes A, B, C, E, F, G, H, I, J, K, and L are all outer boundary nodes, and record their information.

As shown in Figure 4, through the information of the inner boundary nodes that have been determined, it can be seen that an inner boundary node can and can only be connected to two neighbor nodes, first obtain their ID and coordinate information, and randomly select a node such as node T, Suppose its coordinates are (χ _i , y _i ) and then set the coordinates of other nodes as (χ _j , y _j ), by calculating their distance L Select two nodes with the smallest distance to connect, which can be seen as node S and node M in the figure, and then randomly select a connected node such as node M to do the same calculation as node T, and find M nodes except node T Another neighbor node with the smallest distance is connected, and by analogy, when the node with the smallest distance to the last found node is node T except the previous node, the ring LMNOPQRS formed at this time is the inner boundary.

As shown in Figure 5, through the information of the outer border nodes that have been determined, combined with the global routing information of the entire network nodes stored in the base station, first determine whether the two outer border nodes are within their respective one-hop communication ranges, such as node B, C is a neighbor node within the one-hop communication range, and the path BC is the shortest path that can be directly connected, then directly connect to node BC. However, adjacent nodes that are not within the communication range of each hop need to be connected, and it is also necessary to determine whether the path passes through the inner boundary node. For example, suppose nodes F and I are two connected outer boundary nodes, but they are not within the communication range of one hop. It is necessary to find the shortest path connecting node FI through the global routing information. It can be seen that the path FPOI is the shortest path, but this path passes through the inner boundary nodes P and O, so it is ruled out and another path that does not pass through the inner boundary node is found. From the figure, we can see that the path FGHI passing through the nodes G and H is the shortest path, then the connecting node FGHI is the most outer part of the boundary, and so on, the outer boundary can be determined as the ring passing through the node ABCEFGHIJKL .

As shown in Figure 6, through the determined adjacent inner boundary node SR, S has two outer boundary nodes AK, R has two outer boundary nodes BC, assuming that starting from the outer boundary node C of node R to find the outer boundary node of S node The shortest path of the boundary node, we can see from the figure that node B is on the shortest path from C to AK, so replace C with node B, and then node B finds the shortest path BA connected to the outer boundary node A of the inner boundary node S, Then connect BR, SR, SA and the shortest path BA, and the area ABRS surrounded by them is the boundary Face area.

As shown in Figure 7, through the determined outer boundary ABCDEFGHIJK and inner boundary LMNOPQRS, the middle area surrounded by these two rings is the boundary area where we need to find out the toxic gas.

The above is only a preferred embodiment of the present invention, it should be pointed out that for those of ordinary skill in the art, without departing from the technical principle of the present invention, some improvements and modifications can also be made. It should also be regarded as the protection scope of the present invention.

Claims (3)

1. an industrial working toxic gas borderline region localization method, is characterized in that comprising the steps:

(1), each sensor node detect self whether sense toxic gas, distinguish all nodes in toxic gas and all nodes outside toxic gas;

(2), each sensor node all neighbor node broadcasts within the scope of self one-hop propagation, the information data of described node broadcasts at least comprises three kinds: the id information of node, and whether the coordinate information of node and node sense the information of toxic gas;

(3), inner boundary node locating and inner boundary location

Node in all toxic gases, according to the information whether sensing toxic gas received in the information of neighbor node within the scope of a jumping, judges:

3a, suppose that all neighbor nodes of a node all sense toxic gas, then this node is common toxic gas interior nodes, rejects in the calculation;

3b, suppose all neighbor nodes that a node receives information in have at least a node not sense toxic gas, so this node is then inner boundary node, and records corresponding id information and coordinate information;

3c, according to the id information of step 3b record in boundary node location and coordinate information, make inner boundary node form a unique annular channels, be called inner boundary;

(4), external boundary node locating and external boundary location

In node outside all toxic gases, according to the information whether sensing toxic gas received in the packets of information of neighbor node in a jumping broadcasting area, judge:

4a, suppose that all neighbor nodes of a node all do not sense toxic gas, then this node is common toxic gas exterior node, rejects in the calculation;

4b, suppose all neighbor nodes that a node receives information in have at least a node to sense toxic gas, so this node is then external boundary node, and records corresponding id information and coordinate information;

4c, id information according to step 4b record in boundary node location, coordinate information and store the overall routing iinformation that whole network node is in a base station communicated with, make external boundary node form a unique annular channels, be called external boundary;

(5), border Face surface area location

According to the overall routing iinformation that nodal information and the storage whole network node in a base station of inner and outer boundary are communicated with, two adjacent and connected inner boundary nodes and the external boundary node corresponding to them look for the shortest path be connected with each other by overall routing iinformation;

Suppose that two inner boundary nodes all only have an external boundary node, so by the shortest path that overall routing iinformation finds external boundary node to be connected, the surrounded region that is connected with inner and outer boundary node is afterwards just border Face surface area;

Suppose that two inner boundary nodes have the external boundary node of more than 2, so calculated by overall routing iinformation, an external boundary node of one of them inner boundary node looks in the shortest path of the external boundary node of another inner boundary node other external boundary nodes that there is this inner boundary node, the external boundary node before so replacing it with the external boundary node in path; By that analogy, do not comprise other external boundary node in the shortest path that 2 external boundary nodes are connected, then the region that shortest path and inner and outer boundary node surround is border Face surface area;

(6), borderline region location

According to the information of the inner boundary determined and external boundary, determine borderline region, the zone line that inner boundary surrounds with external boundary is toxic gas borderline region.

2. industrial working according to claim 1 toxic gas borderline region localization method, is characterized in that the method that inner boundary node in described step 3c forms a unique annular channels is:

Each inner boundary node is inevitable can be connected and only can connect other 2 inner boundary nodes, according to known coordinate information, supposes that the coordinate of node I is (χ _i, y _i), the coordinate of other nodes is J (χ _j, y _j), calculate I node with other nodal distances get and be connected apart from minimum 2 nodes, get arbitrarily afterwards a direction the like carry out recurrence selection, until get back to first node, make all inner boundary nodes form a unique ring, be called inner boundary.

3. industrial working according to claim 1 toxic gas borderline region localization method, is characterized in that the method that inner boundary node in described step 4c forms a unique annular channels is:

Suppose that two adjacent external boundary nodes need to be connected, according to id information, the overall routing iinformation that coordinate information and storage whole network node is in a base station communicated with, first judge whether in a hop neighbor communication range of sensor node, if it is be directly connected, if not, then judge again two nodes be connected shortest path whether by inner boundary node, if it is this path is rejected, select the shortest path except passing through inner boundary node, be access path if not then selecting it, the like make all external boundary nodes form a unique annular channels, be called external boundary.