WO2019184586A1

WO2019184586A1 - Unmanned aerial vehicle deployment and base station communication enhancement method and system based on gravity model

Info

Publication number: WO2019184586A1
Application number: PCT/CN2019/073513
Authority: WO
Inventors: 伍楷舜; 钟舒馨; 王璐; 邱宇轩
Original assignee: 深圳大学
Priority date: 2018-03-26
Filing date: 2019-01-28
Publication date: 2019-10-03
Also published as: CN108471616A; CN108471616B

Abstract

The present invention is applicable to the technical field of wireless communications and provides an unmanned aerial vehicle deployment and base station communication enhancement method and system based on a gravity model. The method comprises: S1: using a KDivide method to alternately horizontally and vertically divide up a hotspot area so as to ensure that the number of users in each mini-block meets the capacity of a single unmanned aerial vehicle; S2: calculating objective function so as to determine whether an unmanned aerial vehicle needs to be allocated to a mini-block, if so, allocating the unmanned aerial vehicle and performing the next step, and if not, not allocating the unmanned aerial vehicle; S3: positioning the unmanned aerial vehicle, according to EMech, for users who are not within a coverage range; and S4: using RMerge to reverse S1, and combining the mini-blocks in pairs until the mini-blocks are combined into a block of the initial hotspot area. The method effectively improves data provision efficiency of a base station.

Description

Method and system for deploying UAV enhanced base station communication based on physical gravity model

Technical field

The invention belongs to the field of wireless communication technologies, and in particular relates to a method for enhancing base station communication by an outdoor deployment drone based on a physical gravity model.

Background technique

With the continuous development of UAV communication technology, the use of UAVs as air mobile base stations provides a solution to alleviate excessive load on base stations in a short period of time, which is the focus of next generation network providers. Specifically, drones can act as a relay between terrestrial users and terrestrial base stations to meet the growing business needs of hotspots. Compared with traditional ground base stations, drones are more flexible and can be allocated and placed according to user needs. At the same time, due to the flying height of the drone, the obstacles and multipath effects of the ground obstacles are small, so the probability of the UAV communication and the ground user's line of sight connection is large. Therefore, the UAV is deployed as a mobile base station in the urban area. Can make the data rate greatly improved. Some public temporary events, such as concerts, sports or parades, are not an ideal solution for building a base station based on drones if ground-based data cells are unable to provide the desired capacity and coverage.

For the deployment of the UAV, the patent number is 201611150293.7, and the application date is December 14, 2016. The domestic application patent discloses a control method and device for the disaster relief UAV base station. The product periodically adjusts the deployment location and height of each UAV base station by accurately estimating the terrain and the empty channel of the disaster area. The invention can effectively improve the network connectivity rate of the disaster-tolerant communication assisted by the UAV base station and ensure the stability of communication in the disaster area. Patent No. 201580040288.8, filed on July 2, 2015, filed on July 2, 2015, discloses a deployment standard for an unmanned aerial vehicle for improving cellular telephone communications. The product identifies whether there is a mismatch in existing usage coverage by identifying the increased aggregate demand determined in the region compared to the projected aggregate cellular phone demand. Based on the identified mismatch, a plan for signaling and deploying one or more UAVs is determined. The patent number is 201610537734.2, and the application date is July 8, 2016. The domestic application patent discloses a path planning method in the process of data collection and reception of the drone. The product dynamically plans the navigation route of the drone by comprehensively considering the data that the sensor can collect at any time and the obstacles that may occur at any time in the environment, and finally the data collected by the drone in the case of energy limitation. Has the greatest data value.

People mainly provide two major types of solutions. The first type divides the hotspot area into a number of fixed-size small areas and assigns priority to each small area according to the user's needs, and assigns the drone according to the priority. Second, the clustering method is used to place the drone at the center of the cluster. These methods fix the number of drones and are not flexible. We hope to propose an algorithm that can flexibly adjust the number of drones according to user needs.

Summary of the invention

It is an object of the present invention to provide a method and system for deploying a drone to enhance base station communication based on a physical gravity model, aiming at solving the above technical problems.

The present invention is achieved by a method for deploying a drone to enhance base station communication based on a physical gravity model, the method comprising the following steps:

S1. The method of KDivide (kd-tree based division method) is used to divide the hotspot area by alternating horizontal and vertical cutting so that the number of users in each small square divided meets the capacity of a single drone;

S2, determining whether the UAV needs to be allocated in the divided small square by calculating the Objective Function, and if so, assigning the drone and performing the next step, if not, not assigning the drone;

S3. Locating the location of the drone to the uncovered user according to EMech (mechanics equilibrium);

S4. Use RMerge (Reverse Merge Process) to reverse step S1 to merge the divided small squares into two squares until merged into squares of the initial hotspot area.

A further technical solution of the present invention is that the step S1 further includes the following steps:

S11. Determine whether the cutting division divides the direction. If the division direction is not selected, select the division direction s. If the division direction s' has been selected, let s'=s;

S12. Determine whether the number of users in the current square exceeds the capacity of the single drone. If it exceeds, divide the current square evenly according to the dividing direction s and set the dividing direction to the vertical direction s'. If not, stop. The division of the square;

S13. The process of steps S11 and S12 is repeated until the number of users in all the squares satisfies the capacity of a single drone.

According to a further technical solution of the present invention, the step S2 further includes the following steps:

S21. Calculate an Objective Function of the current block and mark it as OF;

S22. Calculate an Objective Function after the current square deploys the drone and mark it as OF';

S23. Determine the size of the OF and OF' of the current block. If the OF is greater than OF', the drone is allocated. If the OF is less than or equal to OF', the drone is not allocated.

According to a further technical solution of the present invention, the step S3 further includes the following steps:

S31. Select an initial placement position in a given block as a random location;

S32. Calculating the resultant force of the user group in the block on the attractive force of the drone;

S33, according to the direction in which the drone is displaced upward in the direction of the attraction force;

S34. Repeating the steps S32 and S33 to make the resultant force of the user group to the drone reach the position of the balance point.

According to a further technical solution of the present invention, the step S4 further includes the following steps:

S41. Determine whether the unmanned aircraft is allocated before the two small squares A and B. If the two small squares A and B are not assigned the drone, merge the two squares to form a new block C, and call step S2 to determine. Whether the new box is assigned a new drone; if two small squares A and B contain a drone and no drone, the two squares are merged to form a new square C, which is within the rectangle of the left and right R _max distances of the original dividing line. Constructing block C', calling step S2 to determine whether block C' is assigned a new drone. If no drone is assigned, step S3 is called to adjust the position of all drones in the block; for example, two small squares A and B are When a drone is assigned, it is first merged into a new block C, and a block C' is constructed in a rectangle with a distance R _max from the original split line. Step S2 is called to determine whether the block C' is assigned a new drone, if no one is assigned. Machine, calculate the distance between two or two drones.

A further technical solution of the present invention is that the step S41 further includes the following steps:

S411. Determine whether the distance between the two drones is less than 2×R _max . If yes, calculate the coverage of the two drones, and calculate the Objective Function of the calculation block of the block according to the convex hull construction block of the coverage range. For OF; if you remove a drone, call S3 step and calculate the Objective Function of the block, denoted as OF'; if OF' is greater than OF, remove a drone, and vice versa; , then perform the next step;

S412. Determine whether the distance between the two drones is less than 4×R _max . If yes, calculate the coverage of the two drones, and calculate the Objective Function of the block as OF according to the convex hull construction block of the coverage range; If adding a drone, call the S3 step and calculate the Objective Function of the block, denoted as OF'; if OF' is greater than OF, add a drone, and vice versa; if not, the distance is greater than 4× R _max does not adjust the position of the drone.

Another object of the present invention is to provide a system for deploying a drone to enhance base station communication based on a physical gravity model, the system including

The area dividing module is configured to divide the hotspot area by using the KDivide method to divide the hotspot area so that the number of users in each small square divided meets the capacity of the single drone;

The calculation and judgment division module is configured to determine whether the unmanned aerial vehicle needs to be allocated in the divided small square by calculating the Objective Function, and if yes, assign the drone and perform the next step; if not, the drone is not allocated;

a positioning module for locating the location of the drone for the user not covered by the EMech;

The merging module is configured to perform the merging of the divided small squares by using the RMerge reversal area dividing module process until the squares of the initial hotspot area are merged.

According to a further technical solution of the present invention, the area dividing module further includes

a dividing direction determining unit, configured to determine whether the cutting division is dividing the direction, and if the dividing direction is not selected, selecting the dividing direction s, if the dividing direction s' has been selected, let s'=s;

The capacity judging unit is configured to judge whether the number of users in the current block exceeds the capacity of a single drone, and if yes, divide the current square evenly according to the dividing direction s and set the dividing direction to the vertical direction of the original s', if not If it is exceeded, the block division is stopped;

The capacity saturation unit is used to repeat the process of dividing the direction judging unit and the capacity judging unit until the number of users in all the blocks satisfies the capacity of a single drone.

According to a further technical solution of the present invention, the calculation determining module further includes

a first calculating unit, configured to calculate an Objective Function of the current block and mark it as OF;

a second calculating unit, configured to calculate an Objective Function after the current square deploys the drone and mark it as OF';

The size judging unit is configured to judge the size of the OF and the OF' of the current block. If the OF is greater than the OF', the drone is allocated. If the OF is less than or equal to OF', the drone is not allocated.

Selecting a location unit for selecting an initial placement location as a random location in a given square;

a joint force calculation unit for calculating the resultant force of the user group in the block on the attractive force of the drone;

a displacement moving unit for shifting a distance upward according to a direction of the unmanned force of the unmanned aerial vehicle;

The joint force balance unit, the process for the recombination force calculation unit and the displacement movement unit, makes the resultant force of the user group to the drone reach the position of the balance point.

The merge module further includes

The UAV allocation unit is used to determine whether the two or two small squares A and B are allocated before the drone; if the two small squares A and B are not assigned the drone, the two squares are merged to form a new square C. And call the calculation to determine the division module process to determine whether the new block is assigned a new drone; if two small squares A, B contain a drone and no drone, then merge two squares to form a new block C, in the original Dividing the left and right distances of the rectangle to construct the block C', calling the calculation to determine the division module process judgment block C, whether to allocate a new drone, if not assigning the drone, calling the positioning module process to adjust all the drones in the block Position; if two small squares A and B are assigned with drones, they are first merged into a new block C, and a block C' is constructed in the rectangle of the left and right distances of the original dividing line, and the calculation is performed to judge the dividing module process to determine whether the block C is Allocate new drones, and if no drones are assigned, calculate the distance between the two drones;

The drone distribution unit further includes

The first distance calculating unit is configured to determine whether the distance between the two drones is less than 2×R _max , and if so, calculate the coverage of the two drones, and calculate the square according to the convex hull structure of the coverage area. Calculate the Objective Function of the block as OF; if you remove a drone, call the positioning module and calculate the Objective Function of the block, denoted as OF'; if OF' is greater than OF, remove a drone, otherwise Do not remove; if no, perform the next step;

a second distance calculating unit, configured to determine whether the distance between the two drones is less than 4×R _max , and if so, calculate the coverage of the two drones, and calculate the square according to the convex hull structure of the coverage area The Objective Function is recorded as OF; if a drone is added, the positioning module is called, and the Objective Function of the block is calculated, denoted as OF'; if OF' is greater than OF, then a drone is added, and vice versa; if not , the distance is greater than 4 × R _max does not adjust the position of the drone.

The invention has the beneficial effects that the data efficiency that the base station can provide is effectively improved by the method, the coverage is more comprehensive, the strength of the signal is enhanced, and the use efficiency of the base station is enhanced.

DRAWINGS

1 is a method and system for deploying a drone to enhance base station communication based on a physical gravity model according to an embodiment of the present invention;

2 is a method and system for deploying a drone to enhance base station communication based on a physical gravity model according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a method and system for deploying a drone to enhance base station communication based on a physical gravity model according to an embodiment of the present invention.

detailed description

As shown in FIG. 1-2, the method for deploying a drone based on a physical gravity model to enhance base station communication is as follows:

In actual reference, the drone is a relay between the base station and the user. The drone communicates with the base station using cellular data, and the drone and the user use WiFi communication operating at 2.4 GHz. The method is based on a divisional idea to cut the hotspot area and reduce the problem. Then introduce the model of physical force, simulate the role of force, treat the user as a negatively charged particle, the drone is a positive electric particle, the user has a powerful effect on the drone until the drone reaches the equilibrium point. This method can be used not only to assign a drone to a single block, but also to move the position of the drone in subsequent steps. At this time, we need to consider a benefit problem, and weigh the benefits and costs by calculating the Objective Function. Finally, re-merging all the small squares into the first big square is the inverse of the division.

Since the capacity of the UAV's coverage users is limited, we first divide the hotspot area, but the division method will directly affect the results of the subsequent allocation. The easiest way is to cut in the same direction. This has the disadvantage of forming a slender strip of area, and the coverage of the drone is abstract. Inspired by the process of constructing the K-D Tree, we propose a method of alternately cutting the area horizontally and vertically, and named it KDivide. The rectangle thus obtained can be more easily distributed to the drone, rationally utilize resources and partially avoid interference between the drones.

Step S1, using KDivide method to divide the hotspot area by horizontal and vertical alternate cutting, so that the number of users in each small square divided meets the capacity of a single drone; the method of KDivide is used to divide the hotspot area alternately horizontally and vertically until each The number of users in a small area meets the capacity of a single drone; the drone is a relay between the base station and the user. The drone communicates with the base station using cellular data, and the drone and the user use WiFi communication operating at 2.4 GHz. The equipment used is an existing wireless commercial device, and no special equipment needs to be installed. In the process of dividing the block, S11, determining whether the cutting division is dividing the direction, if the dividing direction is not selected, selecting the dividing direction s, if the dividing direction s is selected, then let s,=s; S12, determining the user in the current square Whether the number exceeds the capacity of a single drone. If it exceeds, the current square is evenly divided according to the dividing direction s and the dividing direction is set to the vertical direction s. If not, the square dividing is stopped; S13, repeating steps The process of S11 and S12 until the number of users in all the squares meets the capacity of a single drone.

The number of users in a large area exceeds the capacity of a single drone, and the area is horizontally/longitudinally cut; the number of users in the divided small area exceeds the capacity of a single drone, and the small area is taken and Cutting is performed in a direction perpendicular to the cutting direction (vertical and vertical) until the number of users in each small area satisfies the capacity of a single drone. This method is defined as KDivide.

Step S2, judging whether the UAV is required to be allocated in the divided small square by calculating the Objective Function, if yes, assigning the drone and performing the next step, if not, not assigning the drone; whether the small box needs no one In the process of the machine, the following process is also performed, S21, calculating the Objective Function of the current block and marking it as OF; S22, calculating the Objective Function after deploying the UAV in the current block and marking it as OF; S23, Judging the size of OF and OF' of the current block. If OF is greater than OF', the drone is assigned. If OF is less than or equal to OF, the drone is not assigned. Through the above process to complete the unmanned deployment and use.

Objective Function is a custom objective function, Objective Function=Gain(K)-Cost(K). Gain(K) is the increase in throughput achieved after the allocation of K drones, and Cost(K) is the cost of distributing K drones (economic cost, interference cost).

Step S3, according to the EMech, the location of the unmanned aircraft is located to the uncovered user; in the process of locating the drone to the covered user, the following operations are performed, S31, selecting the initial placement position in the given square is Random position; S32, calculating the combined force of the user group on the attraction force of the drone in the block; S33, shifting the distance upward according to the direction of the attraction force of the drone; S34, repeating the process of step S32 and step S33 to make the user group The force of the force of the drone reaches the position of the balance point. In this step, we abstract the user into a negatively charged particle, and the drone is abstracted into a positively charged particle. The gravitational effect between the two is defined as:

k _a is the gravitational coefficient, k _d is the attenuation coefficient, n is the distance from the user to the drone divided by the maximum coverage of the drone, m _u is the quality of the user is 1, m _v is the mass of the drone Is 1,

Is a normalized operation,

Is the square of the diagonal distance.

When the drone randomly selects a point to be placed, the surrounding users will have a powerful effect on the drone. Under this force, the unmanned person moves until it reaches the balance point.

The user is considered to be a negatively charged particle, the drone is considered to be a positively charged particle, and the drone is deployed where the resultant force is zero. This method is defined as EMech.

In step S4, the divided small squares are merged by the RMerge reversal step S1 until they are merged into the squares of the initial hotspot area. In the process of merging the small squares into the initial area large squares, the following operations are performed: S41 reverses the order of step S1, and the small squares are merged between the two squares; S42, if neither the square A nor the square B are assigned the drone, First merge blocks A and B into new block C. Call step S2 to determine if block C is allocating a new drone. S43 If there is no drone in block A and no drone in block B, first merge blocks A and B into new block C. A block C' is constructed in a rectangle of the left and right R _max distances of the original dividing line, and the step S2 is called to determine whether the block C' is assigned a new drone. If no drone is assigned, call S3 to adjust the position of all drones in the box. S44 If both blocks A and B are assigned drones, they are first merged into new blocks C. In the same manner as S43, the block C' is constructed in the rectangle of the distance between the left and right R _max of the original dividing line, and the step S2 is called to determine whether the block C' is assigned a new drone. If no drone is assigned, calculate the distance between the two.

S441 If the distance between the drones is less than 2×R _max , calculate the coverage of the two drones. According to the convex hull construction block of the coverage area, calculate the Objective Function of the block as OF; if remove one unmanned Machine, call S3 step, and calculate the Objective Function of the block, denoted as OF'; if OF' is greater than OF, remove a drone, and vice versa.

S442 If the distance between the drones is less than 4×R _max , calculate the coverage of the two drones. According to the convex hull construction block of the coverage area, calculate the Objective Function of the block as OF; if adding a drone , call S3 step, and calculate the Objective Function of the block, denoted as OF'; if OF' is greater than OF, add a drone, and vice versa; if not, the distance is greater than 4 × R _{max is} not the position of the drone Make any adjustments.

Due to the division, only the number of users is considered, and the location of the user is not considered. For the case of gathering users on the boundary, we need to increase the steps of merging the blocks. In the process of merging, for the drones that are too close to each other, we Consider whether it can be cut, and the result is optimal for more users who are not covered to consider adding or adjusting positions.

As shown in FIG. 3, another object of the present invention is to provide a system for deploying a UAV enhanced base station communication based on a physical gravity model, the system including

The area division module further includes

The calculation and judgment module further includes

The merge module further includes

The drone distribution unit further includes

a second distance calculating unit, configured to determine whether the distance between the two drones is less than 4×R _max , and if so, calculate the coverage of the two drones, and calculate the square according to the convex hull structure of the coverage area The Objective Function is recorded as OF; if a drone is added, the positioning module is called, and the Objective Function of the block is calculated, denoted as OF'; if OF' is greater than OF, then a drone is added, and vice versa; if not , the distance is greater than 4 × R _max does not make any adjustment to the position of the drone.

The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. Within the scope.

Claims

A method for deploying a drone to enhance base station communication based on a physical gravity model, characterized in that the method comprises the following steps:

S1. The method of KDivide is used to divide the hotspot area by alternating horizontal and vertical cutting so that the number of users in each small square divided meets the capacity of a single drone;

S2. Calculate the Objective Function (determine whether the drone needs to be allocated in the divided small square, if yes, assign the drone and perform the next step, if no, the drone is not allocated;

S3. Locating the location of the drone to the user who is not covered according to EMech;

S4. Perform the merging of the divided small squares by the RMerge reversal step S1 until the squares of the initial hotspot area are merged.
The method for deploying a UAV enhanced base station communication based on a physical gravity model according to claim 1, wherein the step S1 further comprises the following steps:

S11. Determine whether the cutting division divides the direction. If the division direction is not selected, select the division direction s. If the division direction s' has been selected, let s'=s;

S12. Determine whether the number of users in the current square exceeds the capacity of the single drone. If it exceeds, divide the current square evenly according to the dividing direction s and set the dividing direction to the vertical direction s'. If not, stop. The division of the square;

S13. The process of steps S11 and S12 is repeated until the number of users in all the squares satisfies the capacity of a single drone.
The method for deploying a UAV enhanced base station communication based on a physical gravity model according to claim 2, wherein the step S2 further comprises the following steps:

S21. Calculate an Objective Function of the current block and mark it as OF;

S22. Calculate an Objective Function after the current square deploys the drone and mark it as OF';

S23. Determine the size of the OF and OF' of the current block. If the OF is greater than OF', the drone is allocated. If the OF is less than or equal to OF', the drone is not allocated.
The method for deploying a UAV enhanced base station communication based on a physical gravity model according to claim 3, wherein the step S3 further comprises the following steps:

S31. Select an initial placement position in a given block as a random location;

S32. Calculating the resultant force of the user group in the block on the attractive force of the drone;

S33, according to the direction in which the drone is displaced upward in the direction of the attraction force;

S34. Repeating the steps S32 and S33 to make the resultant force of the user group to the drone reach the position of the balance point.
The method for deploying a UAV enhanced base station communication based on a physical gravity model according to claim 4, wherein the step S4 further comprises the following steps:

S41. Determine whether the unmanned aircraft is allocated before the two small squares A and B. If the two small squares A and B are not assigned the drone, merge the two squares to form a new block C, and call step S2 to determine. Whether the new box is assigned a new drone; if two small squares A and B contain a drone and no drone, the two squares are merged to form a new square C, which is within the rectangle of the left and right R max distances of the original dividing line. Constructing block C', calling step S2 to determine whether block C' is assigned a new drone. If no drone is assigned, step S3 is called to adjust the position of all drones in the block; for example, two small squares A and B are When a drone is assigned, it is first merged into a new block C, and a block C' is constructed in a rectangle with a distance R max from the original split line. Step S2 is called to determine whether the block C' is assigned a new drone, if no one is assigned. Machine, calculate the distance between two or two drones.
The method for deploying a UAV to enhance base station communication based on a physical gravity model according to claim 4, wherein the step S41 further comprises the following steps:

S411. Determine whether the distance between the two drones is less than 2×R max . If yes, calculate the coverage of the two drones, and calculate the Objective Function of the calculation block of the block according to the convex hull construction block of the coverage range. For OF; if you remove a drone, call S3 step and calculate the Objective Function of the block, denoted as OF'; if OF' is greater than OF, remove a drone, and vice versa; , then perform the next step;

S412. Determine whether the distance between the two drones is less than 4×R max . If yes, calculate the coverage of the two drones, and calculate the Objective Function of the block as OF according to the convex hull construction block of the coverage range; If adding a drone, call the S3 step and calculate the Objective Function of the block, denoted as OF'; if OF' is greater than OF, add a drone, and vice versa; if not, the distance is greater than 4× R max does not make any adjustments to the drone position.
A system for deploying a drone to enhance base station communication based on a physical gravity model, characterized in that the system comprises

The area dividing module is configured to divide the hotspot area by using the KDivide method to divide the hotspot area so that the number of users in each small square divided meets the capacity of the single drone;

The calculation and judgment division module is configured to determine whether the unmanned aerial vehicle needs to be allocated in the divided small square by calculating the Objective Function, and if yes, assign the drone and perform the next step; if not, the drone is not allocated;

a positioning module for locating the location of the drone for the user not covered by the EMech;

The merging module is configured to perform the merging of the divided small squares by using the RMerge reversal area dividing module process until the squares of the initial hotspot area are merged.
The system for deploying a UAV enhanced base station communication based on a physical gravity model according to claim 7, wherein the area dividing module further comprises

a dividing direction determining unit, configured to determine whether the cutting division is dividing the direction, and if the dividing direction is not selected, selecting the dividing direction s, if the dividing direction s' has been selected, let s'=s;

The capacity judging unit is configured to judge whether the number of users in the current block exceeds the capacity of a single drone, and if yes, divide the current square evenly according to the dividing direction s and set the dividing direction to the vertical direction of the original s', if not If it is exceeded, the block division is stopped;

The capacity saturation unit is used to repeat the process of dividing the direction judging unit and the capacity judging unit until the number of users in all the blocks satisfies the capacity of a single drone.
The system for deploying a UAV enhanced base station communication based on a physical gravity model according to claim 8, wherein the calculation and determination module further comprises

a first calculating unit, configured to calculate an Objective Function of the current block and mark it as OF;

a second calculating unit, configured to calculate an Objective Function after the current square deploys the drone and mark it as OF';

The size judging unit is configured to judge the size of the OF and the OF' of the current block. If the OF is greater than the OF', the drone is allocated. If the OF is less than or equal to OF', the drone is not allocated.
The system for deploying a UAV enhanced base station communication based on a physical gravity model according to claim 9, wherein the calculation and determination module further comprises

Selecting a location unit for selecting an initial placement location as a random location in a given square;

a joint force calculation unit for calculating the resultant force of the user group in the block on the attractive force of the drone;

a displacement moving unit for shifting a distance upward according to a direction of the unmanned force of the unmanned aerial vehicle;

The joint force balance unit, the process for the recombination force calculation unit and the displacement movement unit, makes the resultant force of the user group to the drone reach the position of the balance point.

The merge module further includes

The UAV allocation unit is used to determine whether the two or two small squares A and B are allocated before the drone; if the two small squares A and B are not assigned the drone, the two squares are merged to form a new square C. And call the calculation to determine the division module process to determine whether the new block is assigned a new drone; if two small squares A, B contain a drone and no drone, then merge two squares to form a new block C, in the original Dividing the left and right distances of the rectangle to construct the block C', calling the calculation to determine the division module process judgment block C, whether to allocate a new drone, if not assigning the drone, calling the positioning module process to adjust all the drones in the block Position; if two small squares A and B are assigned with drones, they are first merged into a new block C, and a block C' is constructed in the rectangle of the left and right distances of the original dividing line, and the calculation is performed to judge the dividing module process to determine whether the block C is Allocate new drones, and if no drones are assigned, calculate the distance between the two drones;

The drone distribution unit further includes

The first distance calculating unit is configured to determine whether the distance between the two drones is less than 2×R max , and if so, calculate the coverage of the two drones, and calculate the square according to the convex hull structure of the coverage area. Calculate the Objective Function of the block as OF; if you remove a drone, call the positioning module and calculate the Objective Function of the block, denoted as OF'; if OF' is greater than OF, remove a drone, otherwise Do not remove; if no, perform the next step;

a second distance calculating unit, configured to determine whether the distance between the two drones is less than 4×R max , and if so, calculate the coverage of the two drones, and calculate the square according to the convex hull structure of the coverage area The Objective Function is recorded as OF; if a drone is added, the positioning module is called, and the Objective Function of the block is calculated, denoted as OF'; if OF' is greater than OF, then a drone is added, and vice versa; if not , the distance is greater than 4 × R max does not make any adjustment to the position of the drone.