Heuristic optoelectronic-radar sensor deployment method based on mobile path position

Abstract

The present invention discloses a heuristic optoelectronic radar sensor deployment method based on mobile path position, and relates to the technical fields of optoelectronic radar sensor network, sensor node deployment, etc. The present invention first obtains the rectangular area to be monitored and the target moving path, and determines the position of the first sensor; then determines the positions of other sensors, and deploys the sensors to achieve full coverage of the moving target path; then adjusts the sensor state and sensing direction according to the target position until the target leaves the rectangular area to be monitored, and completes the monitoring of the moving target. The method can track and monitor the moving target object in real time, reducing the network deployment cost.

Description

Technical Field

[0001] The present invention relates to the technical fields of photoelectric-radar sensor network, sensor node deployment and the like, and in particular to a heuristic photoelectric-radar sensor deployment method based on mobile path position. Background Art

[0002] Wireless sensor networks have the advantages of high practicality, flexible settings, and strong scalability. They communicate and transmit information through multi-hop, self-organization or collaboration, and can autonomously and intelligently perceive the surrounding environment and complete target tasks. They play an important role in border protection, sea anti-smuggling, motion tracking, military intelligence monitoring and other fields. For nodes in optoelectronic-radar sensor networks for border protection, deployment technology can deploy fixed, random or dynamically movable nodes in the monitoring area through various channels. Different network node deployment methods will have a huge impact on the network's topology, connectivity, network lifetime and service quality. Due to the limited characteristics of the perception range of directed sensor nodes, their perception ability is closely related to the distance and relative position of the node from the target object. The rise and development of intelligent algorithms in recent years have provided new ideas and means for solving complex problems. The literature points out that genetic algorithms and simulated annealing algorithms can be used to solve the composition optimization problem of wireless sensor networks. However, their convergence speed and search time need to be further improved. Summary of the invention

[0003] In view of this, an object of the present invention is to provide a heuristic optoelectronic-radar sensor deployment method based on mobile path position, which can track and monitor mobile target objects in real time and reduce network deployment costs.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] A heuristic optoelectronic-radar sensor deployment method based on mobile path position includes the following steps:

[0006] Step 1: Get the rectangular area to be monitored and the target moving path path. The length of the rectangular area to be monitored is Length, the width is Width, and the lower left corner of the rectangular area to be monitored is the origin. The coordinates of the target entering the rectangular area to be monitored are (a start ,width), the coordinates of the target leaving the rectangular area to be monitored are (a end ,0);

[0007] Step 2: Determine the first sensor position p1 = (x1, y1) = (a start ,width-R), where R is the sensing radius of the sensor;

[0008] Step 3: Determine the position p of the i-th sensor i =(x i ,y i ), whose horizontal and vertical coordinates are:

[0009]

[0010] y i =2b i-1 -y i-1

[0011] Where: i>1, (x i-1 ,y i-1 ) is the position of the i-1th sensor, (a i-1 ,b i-1 ) is the coordinate of the intersection of the target moving path and the sensing range of the i-1th sensor;

[0012] Step 4: Judgement Is it true? If yes, go to step 5. If no, set i=i+1 and go to step 3.

[0013] Step 5: Deploy sensors according to the sensor positions obtained in step 3 to achieve full coverage of the moving target path;

[0014] Step 6: According to the target position at time t (c t ,d t ) adjusts the sensor state and perception direction, where the target position (c t ,d t ) takes the lower left corner of the rectangular area to be monitored as the origin; the specific method is as follows: for any sensor i, determine Is it true? If yes, go to step 7. If no, adjust sensor i to a dormant state.

[0015] Step 7: Adjust the sensing direction α of the i-th sensor i :

[0016]

[0017] Among them, (c, d) is the target position in the coordinate system established with the sensor node as the origin of the coordinate axis;

[0018] Step 8: Continue to execute step 6 until the target leaves the rectangular area to be monitored, thus completing the monitoring of the moving target.

[0019] The present invention has the following beneficial effects:

[0020] 1. Aiming at the problem of sensor network node deployment based on mobile target coverage, the present invention proposes a heuristic solution algorithm based on mobile path position. First, based on the mobile path position information, a heuristic method is used to determine the position of the sensor node. Then, the position of the sensor node is fixed, and the state and perception direction of the node are adjusted according to the position information of the mobile target object.

[0021] 2. The present invention designs a feasible node deployment scheme for specific application scenarios. The scheme can track and monitor mobile target objects in real time, reducing the network deployment cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of the optoelectronic-radar perception model.

[0023] Figure 2 Schematic diagram of sensor node locations.

[0024] Figure 3 Schematic diagram of node tracking and monitoring at t=1.

[0025] Figure 4 Schematic diagram of node tracking and monitoring at t=2.

[0026] Figure 5 Schematic diagram of node tracking and monitoring at t=3. DETAILED DESCRIPTION

[0027] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0028] A heuristic optoelectronic-radar sensor deployment method based on mobile path position includes the following steps:

[0029] Step 1: Get the rectangular area to be monitored and the target moving path. In large scale, the uneven border line can be approximated as a smooth straight line segment. Therefore, the border line can be used as the long side of the rectangle, and the coordinates of the outermost point of the area to be monitored can be used to determine a rectangular area with a length of Length and a width of Width covering the area to be monitored. In addition, using prior information and positioning technology, it can be assumed that the moving path of the mobile target object crossing the monitoring area is known, that is, the target object will move along the moving path. Therefore, the coordinates of the target entering the rectangular area can be obtained as (a start ,width), the coordinates of the target leaving the rectangular area are (a end ,0);

[0030] Step 2: Determine the first sensor position p1 = (x1, y1) = (a start,width-R), where: R is the sensing radius of the sensor;

[0031] Step 3: Determine the position p of the i-th sensor i =(x i ,y i ), whose horizontal and vertical coordinates are:

[0032]

[0033] y i =2b i-1 -y i-1

[0034] Where: i>1, (x i-1 ,y i-1 ) is the position of the i-1th sensor, (a i-1 ,b i-1 ) is the coordinate of the intersection of the target moving path and the sensing range of the i-1th sensor;

[0035] Step 4: Judgement Whether it is established, that is, whether the i-th sensor can cover the coordinates of the target moving path leaving the rectangular area to be monitored (a end ,0), if yes, go to step 5, if no, set i=i+1 and go to step 3;

[0036] Step 5: Deploy sensors according to the sensor positions obtained in step 3 to achieve full coverage of the moving target path;

[0037] Step 6: According to the target position at time t (c t ,d t ) adjusts the sensor’s sensing direction, where the target position (c t ,d t ) is the coordinate with the lower left corner of the rectangular area to be monitored as the origin. For any sensor i, determine Is it true? If yes, go to step 6. If no, adjust the sensor i to be in the dormant state.

[0038] Step 7: Adjust the i-th sensor sensing direction α i :

[0039]

[0040] Where: (c, d) is the target position in the coordinate system established with the sensor node as the origin of the coordinate axis;

[0041] Step 8: Continue to execute step 6 until the target leaves the detection area, and the detection of the moving target is completed.

[0042] Here is a more specific example:

[0043] A heuristic optoelectronic-radar sensor mobile target coverage deployment method based on mobile path position is proposed. In order to solve the mobile target coverage optimization problem of light spot-radar sensor nodes, the perception model of optoelectronic-radar sensor nodes is transformed into a four-tuple (p n ,α n ,β n ,R n ) to indicate, for example Figure 1 As shown. Among them, p n =(x n ,y n ) is the position of the sensor node, which is also the origin of the corresponding coordinate axis, α n is the angle between the fan midline and the positive direction of the x-axis, which is used to indicate the sensing direction of the node. n is the perception half angle, 2β n is the perception angle, R n is the sector radius, p t =(a t ,b t ) is the position of the target object at time t. When the monitored target object is within the sensing range of the node, it means that it can be sensed and covered by the node.

[0044] During the node deployment process of the sensor network, for movable target objects, such as people, cars, ships, etc., sensor nodes can be used to sense the direction adjustment or mobile sensor nodes can be used to track and cover the target objects, so as to avoid relying solely on static node monitoring to generate large amounts of data transmission and energy consumption.

[0045] To facilitate analysis, the following assumptions need to be made about the optoelectronic-radar sensor network:

[0046] (1) After the initial deployment, the positions of all sensor nodes remain unchanged, and the sensing angle and sensing radius also remain unchanged during the adjustment process. Only the sensing direction can be adjusted;

[0047] (2) Sensor nodes of the same type have the same physical characteristics, that is, the parameters such as sensing angle, sensing radius, sensing ability and range are the same, and the sensing half-angle β is 45°, that is, the sensing angle is 90°;

[0048] (3) All sensor nodes can obtain information such as their own location and sensing direction through GPS, and each sensor node can adjust its own sensing direction by rotating its sensing field of view;

[0049] (4) All sensor nodes can freely switch between sleep and working states.

[0050] Therefore, the problem of sensor network node deployment based on mobile target coverage is to consider the mobility of the monitored target object. When the target object crosses the border and gradually enters the monitoring area, how to deploy the minimum number of sensor nodes to perform real-time tracking and monitoring on it while ensuring the quality of tracking and monitoring.

[0051] According to the assumption, the sensing angle and sensing radius of sensor nodes of the same type are the same, so the sensing model quadruple (p n ,α n ,β n ,R n ) is abbreviated as (p n ,α n ,β,R), and the perception half angle β = 45°.

[0052] This method first determines the position of the sensor node based on the mobile path location information using a heuristic method. Then, the sensor node position is fixed and the node state and sensing direction are adjusted according to the location information of the moving target object.

[0053] Specifically, the steps of this method are as follows:

[0054] (1) Assume that the area to be monitored is a rectangular area with a length of 100 km and a width of 30 km. The sensing radius R of the sensor node is 10 km. According to the assumption, the detection range β of the sensor node is 45°, that is, the sensing angle is 90°. Assume that the coordinates of the target entering the rectangular area are (a start ,30), the coordinates of the target leaving the rectangular area are (a end ,0).

[0055] (2) Determine the position of the first sensor: p1 = (x1, y1) = (a start ,20);

[0056] (3) Determine the second sensor position:

[0057]

[0058] Where c is the horizontal coordinate of the intersection of the moving path and the sensing range of the first sensor.

[0059] (4) Calculation The second sensor can cover (a end ,0)Therefore, two sensors can be used to cover the target moving path;

[0060] (5) Deploy the two sensors obtained above to the area to be monitored to achieve full coverage of the target moving path, such as Figure 2 shown.

[0061] (6) Figure 3 As shown, assuming that at t=1, the target moves to the third quadrant of the coordinate system of node S1, then at this time, the sensing direction of node S1 is α1=arctan(b1 / a1)-π, and node S2 is in a dormant state.

[0062] (7) Figure 4 As shown, assuming that at t=2, the target moves to the second quadrant of the node S2 coordinate system, then node S1 is in a dormant state, and the sensing direction of node S2 is α2=arctan(b1 / a1)+π.

[0063] (8) Figure 5 As shown, assuming that at t=3, the target leaves the rectangular monitoring area, then nodes S1 and S2 are both in a dormant state, completing the monitoring of the moving target.

Claims

1. A heuristic optoelectronic-radar sensor deployment method based on mobile path position, characterized in that: The following steps are involved: Step 1: Get the rectangular area to be monitored and the target moving path path. The length of the rectangular area to be monitored is Length, the width is Width, and the lower left corner of the rectangular area to be monitored is the origin. The coordinates of the target entering the rectangular area to be monitored are (a start ,width), the coordinates of the target leaving the rectangular area to be monitored are (a end ,0); Step 2: Determine the first sensor position p1 = (x1, y1) = (a start ,width-R), where R is the sensing radius of the sensor; Step 3: Determine the position p of the i-th sensor i =(x i ,y i ), whose horizontal and vertical coordinates are: the i =2b i-1 -y i-1 Where: i>1, (x i-1 ,y i-1 ) is the position of the i-1th sensor, (a i-1 ,b i-1 ) is the coordinate of the intersection of the target moving path and the sensing range of the i-1th sensor; Step 4: Judgement Is it true? If yes, go to step 5. If no, set i=i+1 and go to step 3. Step 5: Deploy sensors according to the sensor positions obtained in step 3 to achieve full coverage of the moving target path; Step 6: According to the target position at time t (c t ,d t ) adjusts the sensor state and perception direction, where the target position (c t ,d t ) takes the lower left corner of the rectangular area to be monitored as the origin; the specific method is as follows: for any sensor i, determine Is it true? If yes, go to step 7. If no, adjust sensor i to a dormant state. Step 7: Adjust the sensing direction α of the i-th sensor i : Among them, (c, d) is the target position in the coordinate system established with the sensor node as the origin of the coordinate axis; Step 8: Continue to execute step 6 until the target leaves the rectangular area to be monitored, thus completing the monitoring of the moving target.

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