Unmanned aerial vehicle return control method and device, electronic equipment and storage medium

Abstract

Embodiments of the present application relate to a kind of unmanned aerial vehicle return control method, device, electronic equipment and storage medium, comprising: in response to return control signal, the current position information of each unmanned aerial vehicle in multiple unmanned aerial vehicles is acquired;Based on current position information, the three-dimensional distance of the current position of each unmanned aerial vehicle and target landing point is calculated respectively;Multiple unmanned aerial vehicles are sorted based on three-dimensional distance;According to the result of sorting, the return initial height and return speed of each unmanned aerial vehicle are set;Control each unmanned aerial vehicle returns according to respective return initial height and return speed.The control method provided by the present application calculates the three-dimensional distance of the current position of multiple unmanned aerial vehicles and target landing point and sorts, so that the unmanned aerial vehicle closest to distance returns preferentially, avoids multiple unmanned aerial vehicles simultaneously to occupy return channel;While passing through reference height determination, using height offset rule, the safety interval in vertical direction is constructed in multiple unmanned aerial vehicles collaborative scene, so that the collision risk of unmanned aerial vehicle in return route is greatly reduced.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of unmanned aerial vehicle (UAV) control technology, and in particular to a UAV return-to-home control method, device, electronic device, and storage medium. Background Technology

[0002] With the rapid development of drone technology, multi-rotor drones, with their advantages of maneuverability, convenient take-off and landing, and high operational efficiency, have been widely used in various fields such as surveying and exploration, agricultural plant protection, power line inspection, and emergency rescue. In actual operations, to improve the operational range and work efficiency, the collaborative operation mode of multiple multi-rotor drones is becoming increasingly popular. Through the division of labor and cooperation among multiple drones, large-scale, heavy-load, and high-precision tasks that are difficult for a single drone to undertake can be completed, becoming an important development trend in current drone applications.

[0003] In collaborative operations, the flight safety of drones directly determines the success or failure of the mission, and the ability to return to base after losing contact is one of the key technologies to ensure drone flight safety. When multi-rotor drones encounter emergencies such as signal interruption, insufficient power, or severe weather interference during operations, if they cannot reliably return to base after losing contact, the drones are very likely to be lost or damaged, causing not only economic losses but also potentially affecting the smooth progress of the entire collaborative operation and even posing safety hazards.

[0004] Currently, all existing multi-rotor drone return-to-home technologies on the market are developed and applied based on the independent operation of a single drone. For scenarios where a single drone loses contact, existing technologies can achieve a certain degree of return-to-home functionality through methods such as preset return points, GPS positioning and tracing, and inertial navigation assistance, which can basically meet the safety requirements of routine single-drone operations.

[0005] However, in scenarios involving multiple multi-rotor drones operating collaboratively, existing return-to-home technologies for lost contact exhibit significant limitations and shortcomings, failing to meet the actual needs of collaborative operations. Firstly, in multi-drone collaborative operations, the flight paths, operational areas, and relative positions of each drone are interconnected. Using the same return-to-home logic as for a single drone cannot ensure the orderly return of multiple lost drones, potentially leading to some drones failing to return to their designated landing points. Secondly, when multiple drones simultaneously lose contact, if each follows its own return path, overlapping flight paths and excessively close proximity can easily occur, potentially causing collisions and resulting in simultaneous damage to multiple drones and more severe economic losses. Summary of the Invention

[0006] Based on the above-mentioned situation of the prior art, the purpose of the embodiments of the present invention is to provide a method, device, electronic device and storage medium for controlling the return home of unmanned aerial vehicles (UAVs), which can be adapted to the multi-UAV cooperative operation mode, and can realize the reliable return home of multiple UAVs after losing contact and effectively avoid collisions.

[0007] To achieve the above objectives, according to a first aspect of the present invention, a method for controlling the return-to-home of a drone is provided, applied in a multi-drone cooperative operation mode, wherein multiple drones are flying and operating in the air, and the multiple drones are connected in communication; the method includes: In response to the return-to-home control signal, the current position information of each of the multiple drones is obtained; Based on the current location information, the three-dimensional distance between the current position of each UAV and the target landing point is calculated; wherein, the target landing point is used to determine the landing position of each UAV. The multiple drones are sorted based on the three-dimensional distance; Based on the sorting results, set the initial return altitude and return speed for each UAV; Control each drone to return to its original altitude and speed.

[0008] Furthermore, sorting the multiple drones based on the three-dimensional distance includes: The multiple drones are sorted from smallest to largest based on the three-dimensional distance, and the multiple drones are sequentially designated as drone number 1, drone number 2, ..., drone number N; Where N represents the total number of drones.

[0009] Furthermore, the initial return altitude for each drone is set according to the following formula: in, Let represent the initial return altitude of the i-th UAV, i = 1, 2, ..., N; N represents the total number of UAVs. The reference altitude is set as the maximum value among the current altitude of multiple UAVs, the preset return-to-home altitude, and the maximum waypoint altitude. This represents the dynamic altitude difference between the initial return altitude of each drone and the reference altitude. This dynamic altitude difference is related to the total number of drones and the remaining battery power of each drone.

[0010] Furthermore, the dynamic height difference is set according to the following formula: in, This indicates the preset reference interval. This represents the remaining battery percentage of the i-th drone.

[0011] Furthermore, control each drone to return to its original return altitude and speed, including: Determine whether the current altitude of multiple drones is equal to the reference altitude; When the current altitude of multiple drones is equal to the reference altitude, control the first drone to return from its current position, and control the second to Nth drones to rise to their respective dynamic altitude differences to reach their initial return altitudes before returning. When the current altitude of multiple drones is lower than the reference altitude, the first drone is controlled to rise to the reference altitude and then return to home. The second to Nth drones are controlled to rise to the reference altitude and then return to home when the sum of the differences between the reference altitude and their respective dynamic altitudes reaches their respective initial return altitudes.

[0012] Furthermore, controlling each drone to return to its own initial return altitude and return speed also includes: Control each drone to fly from its initial return altitude at the same horizontal speed to directly above its respective landing position, and then descend to its respective landing position at the same vertical speed; or, Each drone is controlled to fly from its initial return altitude at the same horizontal speed for its corresponding preset horizontal flight distance, and then descend in a straight line at the same oblique speed and its preset descent angle to its respective landing position.

[0013] Furthermore, the method also includes: Real-time acquisition of wireless signal strength between the UAV and the ground control station; When the wireless signal strength remains below the second signal strength threshold for a first threshold period of time, it is determined that the communication between the UAV and the ground control station is interrupted, and the return-to-home control signal is triggered.

[0014] According to a second aspect of the present invention, a drone return-to-home control device is provided, applied in a multi-drone cooperative operation mode, wherein multiple drones are flying and operating in the air, and the multiple drones are communicatively connected; the device includes: The location information acquisition module is used to acquire the current location information of each of the multiple drones in response to the return-to-home control signal; A three-dimensional distance determination module is used to calculate the three-dimensional distance between the current position of each UAV and the target landing point based on the current position information; wherein, the target landing point is used to determine the landing position of each UAV. A sorting module is used to sort the multiple drones based on the three-dimensional distance; The return-to-home parameter setting module is used to set the initial return-to-home altitude and return-to-home speed of each UAV according to the sorting results; The return-to-home control module is used to control each drone to return to its own initial return-to-home altitude and speed.

[0015] According to a third aspect of the present invention, an electronic device is provided, including a memory, a processor, and executable instructions stored in the memory and executable on the processor, wherein the processor, when executing the executable instructions, implements the control method provided in the first aspect of the present invention.

[0016] According to a fourth aspect of the present invention, a computer-readable storage medium is provided having computer-executable instructions stored thereon, which, when executed by a processor, implement the control method as described in the first aspect of the present invention.

[0017] In summary, the embodiments of the present invention provide a method, device, electronic device, and storage medium for unmanned aerial vehicle (UAV) return-to-home control, applied in a multi-UAV cooperative operation mode. The method includes: in response to a return-to-home control signal, acquiring the current position information of each UAV among the multiple UAVs; calculating the three-dimensional distance between the current position of each UAV and the ground target position based on the current position information; wherein the target landing point is used to determine the landing position of each UAV; sorting the multiple UAVs based on the three-dimensional distance; setting the initial return-to-home altitude and return-to-home speed of each UAV according to the sorting result; and controlling each UAV to return to home according to its own initial return-to-home altitude and return-to-home speed. The control method provided by this invention employs a dynamic distance sorting mechanism to calculate and sort the three-dimensional distances between the current positions of multiple UAVs and the target landing point. This prioritizes the return of the closest UAV, while the furthest UAV plans its return path after climbing in layers. This avoids multiple UAVs simultaneously vying for the return path and improves return efficiency. Simultaneously, it combines a height-layered anti-collision strategy. By determining the reference height and utilizing height offset rules, a vertical safety interval is constructed in the multi-UAV collaborative scenario, greatly reducing the risk of collisions between UAVs in both the horizontal and vertical directions along the return path. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the communication link in the multi-machine collaborative operation mode provided by the embodiments of the present invention; Figure 2 This is a flowchart of the UAV return-to-home control method provided in the embodiments of the present invention; Figure 3 This is a block diagram of the unmanned aerial vehicle (UAV) return-to-home control device provided in the embodiments of the present invention; Figure 4 This is a schematic diagram of the structure of the electronic device provided in the embodiment of the present invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0020] It should be noted that, unless otherwise defined, the technical or scientific terms used in one or more embodiments of the present invention should have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in one or more embodiments of the present invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the element or object listed following the word and its equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect.

[0021] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings. One embodiment of the present invention provides a method for controlling the return of a drone, applied in a multi-drone collaborative operation mode. The multi-drone collaborative operation mode involved in this embodiment refers to multiple drones flying and cooperating in the air. The drone type is preferably a multi-rotor drone, but other types of drones can also be used, such as fixed-wing drones, compound-wing drones, unmanned helicopters, etc.; the operation scenarios include, for example, surveying and exploration, agricultural plant protection, power line inspection, emergency rescue, and material hoisting. In the multi-drone collaborative operation mode, multiple drones are connected to a ground control station via wireless communication, and redundant connections are achieved between the drones through wireless communication. In the following embodiments of the present invention, in the multi-drone collaborative operation mode, the multiple drones fly at the same altitude. Figure 1 The diagram shows a communication link in a multi-machine collaborative operation mode according to an embodiment of the present invention, such as... Figure 1 As shown, when multiple drones are operating in the air, the communication data link consists of two parts: "between the drone and the ground control station" and "between the drones themselves." Figure 1 The system includes wireless links A and B. When wireless link A is disconnected due to signal obstruction or interference, the ground control station loses control of the UAV and its flight status monitoring; this is considered a state of communication loss for the UAV. Since wireless link B between UAVs is typically designed with redundancy, the present invention does not consider the scenario of communication loss between UAVs.

[0022] The UAV return-to-home control method provided in this invention can be applied to the flight control system of a UAV. Figure 2 The flowchart of the UAV return-to-home control method according to an embodiment of the present invention is shown below, as follows: Figure 2 As shown, the method includes the following steps: S202. In response to the return-to-home control signal, acquire the current position information of each of the multiple UAVs. The current position information can be represented using three-dimensional spatial coordinates, which can be based on a local East-North-Up (ENU) Cartesian coordinate system, with the coordinates of the target landing point as the origin O(…). , , The current location information of drone i is represented as ( , , ).

[0023] The return-to-home control signal is generated by the UAV flight control system. It can be triggered based on the situation where communication between the UAV and the ground control station is interrupted, as described in the following embodiments; or it can be triggered based on relevant command signals sent by the ground control station.

[0024] S204. Based on the current location information, calculate the three-dimensional distance between the current position of each UAV and the target landing point. Based on the current location information obtained in the above steps, in this embodiment of the invention, the Euclidean distance formula is used to calculate the three-dimensional distance between the current position of each UAV and the target landing point. It can be represented as: Where i = 1, 2, 3, ..., N, N represents the total number of drones. , , ) represents the current location information of the i-th drone, ( , , The coordinates of the target landing point are indicated by . The target landing point is used to determine the landing position of each UAV. The landing position of each UAV can be its takeoff point or a preset return landing point. The target landing point is the center point of the formation area formed by the projection points of multiple UAVs on the horizontal plane during the landing phase, that is, the center point of the area enclosed by the landing positions of multiple UAVs.

[0025] S206. Sort multiple drones based on three-dimensional distance. Optionally, sort the multiple drones based on the three-dimensional distance from smallest to largest, and assign the drones sequentially as Dr. 1, Dr. 2, ..., Dr. N. Specifically, sort the three-dimensional distances between the current position of each drone and the target landing point obtained in the above steps according to the numerical value of the three-dimensional distance from smallest to largest. Sort the multiple drones corresponding to the three-dimensional distances according to the sorted order, and assign the drones sequentially as Dr. 1, Dr. 2, ..., Dr. N. The three-dimensional distances between the current position of Dr. 1 and Dr. N and the target landing point increase sequentially.

[0026] S208. Set the initial return-to-home altitude and return-to-home speed for each drone based on the sorting results. To prevent collisions when multiple drones return to home, the return-to-home altitude and return-to-home speed of the drones are set.

[0027] According to certain optional implementation methods, the return-to-home altitude of the drones is set in layers, and the initial return-to-home altitude of each drone is set according to the following formula: in, Let represent the initial return altitude of the i-th UAV, i=1,2,……,N, where N represents the total number of UAVs; This indicates the reference altitude, which is set to the maximum value among the current altitude of multiple drones, the preset return-to-home altitude, and the maximum waypoint altitude. This represents the dynamic altitude difference between the initial return altitude of each drone and the reference altitude. This dynamic altitude difference is related to the total number of drones and the remaining battery power of each drone.

[0028] According to certain optional implementation methods, the dynamic height difference can be set according to the following formula: in, Indicates the preset reference interval, which is optional. hour, meters, when hour, That is, when the number of drones is small, a larger safety interval is set; when the number of drones increases to a certain extent, the vertical interval is compressed to improve the utilization rate of limited airspace. However, this invention is not limited to this; the preset baseline interval... The settings and specific values ​​can also be adjusted as needed. The remaining battery percentage of the i-th drone represents the ratio of its current remaining battery capacity to its total battery capacity, expressed as a percentage. By using the remaining battery percentage as a weight for altitude allocation, drones with lower remaining battery power can be set a relatively lower initial return altitude to save energy and ensure safe return. Furthermore, incorporating the square root of the total number of drones into the formula ensures that the growth rate of altitude stratification is slower than the growth rate of the total number of drones, preventing unlimited growth of altitude stratification. Combined with the setting of a baseline interval, this ensures sufficient vertical space isolation for drones, maintaining aerodynamic stability during flight. Setting the initial return altitude of drones according to the above formula balances multiple dimensions such as drone endurance, safety, and scalability, achieving multi-objective optimization of return altitude setting.

[0029] According to certain optional implementation methods, the return-to-home speed of the drones can be set. Optionally, the return-to-home speed of each drone can be the same, that is, the return-to-home speed of each drone can be set to the same value. The specific value of the return-to-home speed can be set according to the actual situation.

[0030] S210. Control each UAV to return to its respective initial return altitude and return speed. Specifically, control each UAV to return to its respective landing position according to its respective initial return altitude and return speed.

[0031] According to certain optional implementations, controlling each drone to return to its home position at its respective initial altitude and speed includes: Determine whether the current altitude of multiple drones is equal to the reference altitude.

[0032] When the current altitude of multiple drones is equal to the reference altitude, control the first drone to return from its current position, and control the second to Nth drones to rise to their respective dynamic altitude differences to reach their initial return altitude before returning.

[0033] When the current altitude of multiple drones is lower than the reference altitude, control the first drone to rise to the reference altitude and then return to home. Control the second to Nth drones to rise to the reference altitude and then return to home when the sum of the differences between the reference altitude and their respective dynamic altitudes reaches their respective initial return altitudes.

[0034] According to certain optional implementations, controlling each drone to return to its own initial return altitude and return speed can be achieved by controlling each drone to fly from its own initial return altitude at the same horizontal speed to directly above its own landing position, and then descending to its own landing position at the same vertical speed.

[0035] The total horizontal flight distance of each drone as it flies to directly above its respective landing position. (That is, the horizontal distance between the current position of each drone and its respective landing position) can be determined using the following formula: in, Where i = 1, 2, 3, ..., N, N represents the total number of drones. , ) represents the projected coordinates of the current position of the i-th UAV on the horizontal plane. , ) represents the projected coordinates of the landing position of the i-th UAV on the horizontal plane. , () represents the projected coordinates of the target landing point on the horizontal plane. , This represents the preset offset of the landing position of the i-th UAV relative to the target landing point in the horizontal plane. The preset offset can be determined based on the number of UAVs, the UAVs' projected formation in the horizontal plane, and the spacing between UAVs.

[0036] According to the UAV return-to-home control method provided in this embodiment, the initial return-to-home altitude of the UAVs ranked higher (i.e., those closer to the target landing point) is lower than that of the UAVs ranked lower (i.e., those farther from the target landing point). This ensures that the UAVs ranked higher meet the initial return-to-home altitude requirement first, followed by the UAVs ranked lower. Thus, the UAVs ranked higher begin their return-to-home process first, followed by the UAVs ranked lower. This achieves temporal isolation during the horizontal return-to-home phase and spatial isolation through altitude stratification. During the vertical descent phase, the UAVs that arrive above the landing position first land first, followed by the UAVs arriving later, achieving temporal isolation. Furthermore, the landing positions of each UAV are determined based on the target landing point and are spaced apart, achieving spatial isolation. Using the UAV return-to-home control method provided by this invention, the risk of collision can be fundamentally eliminated in both the horizontal return-to-home and vertical descent phases.

[0037] According to certain optional implementations, in order to improve return-to-home efficiency while ensuring safety, each UAV is controlled to return at its own initial return-to-home altitude and speed. Alternatively, each UAV can be controlled to fly from its initial return-to-home altitude at the same horizontal speed for its corresponding preset horizontal flight distance, and then descend in a straight line at the same oblique speed and its own preset descent angle to its respective landing position. Wherein, the preset horizontal flight distance of the i-th UAV... It can be determined using the following formula: in, The step interval, which represents the horizontal flight distance, can be set according to the drone's performance and safety requirements. This represents the horizontal distance between the current position of each drone and its landing position. The calculation method is the same as the total horizontal flight distance in the previous embodiment, and will not be repeated here.

[0038] Each drone flies horizontally from its initial return altitude according to the preset horizontal flight distance determined above. Then, they fly at a preset descent angle (straight descent at an angle) to their respective landing positions. satisfy: in, The remaining horizontal distance before oblique flight (straight-line descent) is represented as: Angled flight distance (straight-line descent distance) The remaining horizontal distance before diagonal flight can be used and initial altitude of return The calculation yielded: Following the steps above, control multiple drones to return to their origin sequentially until all drones have returned, indicating the completion of the drone return process. This method allows later-arriving drones to have a larger descent angle, enabling them to pass through low-altitude airspace more quickly and avoid collisions with drones ahead, thus ensuring a safe and rapid landing for each drone. In calculating the horizontal flight distance, introducing a step interval generates an adjustable difference in horizontal flight distance between adjacent drones, thus ensuring horizontal staggering between drones while considering vertical layering.

[0039] In the above embodiments, the landing position of each UAV can be determined based on the target landing point. Specifically, with the target landing point as the center, the landing position of each UAV is determined based on the relative positional relationship of the formation formed by the projection points of multiple UAVs on the horizontal plane during the landing phase. For example, during the landing phase, the formation formed by the projection points of multiple UAVs on the horizontal plane can be the same as the formation during multi-UAV collaborative operations; where the formation is the same means that the relative positional relationship between the multiple UAVs remains unchanged, including the case where the relative positional relationship is completely consistent, or the case where the relative positional relationship remains unchanged but the overall formation is scaled proportionally. However, the present invention is not limited to this, and the formation formed by the projection points of multiple UAVs on the horizontal plane during the landing phase can also be different from the formation during multi-UAV collaborative operations.

[0040] According to certain optional implementations, the above-described UAV return-to-home control method further includes step S200: S200: Real-time acquisition of wireless signal strength between the UAV and the ground control station; when the wireless signal strength is continuously lower than the second signal strength threshold within a first threshold time, it is determined that the communication between the UAV and the ground control station is interrupted, and a return-to-home control signal is triggered.

[0041] According to certain optional implementations, the return-to-home control signal is triggered when communication between the UAV and the ground control station is interrupted. The occurrence of communication interruption, i.e., loss of connection, can be determined by monitoring the wireless signal strength between the UAV and the ground control station. Optionally, the wireless signal strength between the UAV and the ground control station is collected in real time; when the wireless signal strength remains below a second signal strength threshold for a first threshold period, for example, when the signal strength is below -90 dBm for 10 consecutive seconds, it is determined that communication between the UAV and the ground control station is interrupted, and the return-to-home control signal is triggered. In response to this return-to-home control signal, the steps described above in this embodiment of the invention are used to control the lost UAV to return to home.

[0042] In multi-drone collaborative operation mode, multiple drones connect to the ground control station wirelessly. This can be divided into two scenarios: First, a master drone (the one communicating with the ground control station among multiple drones) connects to the ground control station, and other drones communicate through the master drone. In this case, communication interruption refers to the interruption of communication between the master drone and the ground control station. Second, multiple drones communicate with the ground control station individually. In this case, communication interruption means that communication between all drones and the ground control station is interrupted. Because the communication between multiple drones is redundant, as long as one drone can communicate with the ground control station, the other drones can communicate through that drone. This is not considered a communication interruption. Optionally, the communication between drones and the ground control station (specifically, between the master drone and the ground control station or between each drone and the ground control station) uses the 1.4GHz frequency band, and the drones are wirelessly interconnected via WiFi communication links. However, this invention is not limited thereto. The communication frequency band between the UAV and the ground control station includes, but is not limited to, the 1.4 GHz band. The specific communication frequency band can be adjusted according to actual needs.

[0043] The technical solution of the present invention will be described below with reference to specific embodiments.

[0044] In a power operation scenario, four multi-rotor drones were used for material transportation. The main drone communicated with the ground control station, and the other drones communicated with the ground control station through the main drone. During the transportation, due to the obstruction of the mountain, the main drone lost communication with the ground control station, triggering the drone disconnection and return-to-home procedure.

[0045] For ease of explanation, assume the target landing point is the origin, with coordinates (0,0,0). When the four drones are operating collaboratively, they are flying at the same altitude, with a horizontal distance of 10 meters between each drone. The current coordinates of the first drone are (600,800,225), the second drone (610,800,225), the third drone (600,810,225), and the fourth drone (610,810,225). When contact is lost, the drones are flying at an altitude of 225 meters. The preset return-to-home altitude is 250 meters, the maximum waypoint altitude is 240 meters, and the return-to-home speed is set to 10 meters / second horizontally, 5 meters / second vertically, and 8 meters / second diagonally. At the time of loss of contact, the remaining battery percentages of the four drones are 58%, 62%, 55%, and 60%, respectively.

[0046] Distance calculation between the UAV and the target landing point: According to the calculation method provided in the above embodiments of the present invention, the three-dimensional distances between the UAV and the target landing point are calculated to be 1025 meters, 1030.9 meters, 1032.8 meters and 1038.7 meters respectively. After sorting the above three-dimensional distances in ascending order, the corresponding UAVs are sorted and numbered. The UAV with a three-dimensional distance of 1025 meters is set as UAV 1, the UAV with a three-dimensional distance of 1030.9 meters is set as UAV 2, the UAV with a three-dimensional distance of 1032.8 meters is set as UAV 3, and the UAV with a three-dimensional distance of 1038.7 meters is set as UAV 4.

[0047] Reference altitude confirmation: The reference altitude is set to the maximum value among the current altitude of multiple drones, the preset return-to-home altitude, and the maximum altitude of waypoints. The current altitude of multiple drones is 225 meters, the preset return-to-home altitude is 250 meters, and the maximum altitude of waypoints is 240 meters, thus the reference altitude is 250 meters.

[0048] According to the UAV collision avoidance height layering method provided in the above embodiments of the present invention, the initial return altitude of each UAV is calculated: Confirmation of total horizontal flight distance: In this embodiment, the relative positional relationship between the four UAVs during the landing phase remains unchanged but proportionally reduced compared to the relative positional relationship between the UAVs during collaborative operations. Assuming the projected formation of the four UAVs on the horizontal plane is a square, and the horizontal distance between the four UAVs is the same at 8m, the absolute value of the preset offset is 4m. Centered on the projected coordinates (0,0) of the target landing point on the horizontal plane, the projected coordinates of the landing positions of UAVs 1 through 4 on the horizontal plane are represented as (-4,-4), (4,-4), (-4,4), and (4,4), respectively. Based on the method for calculating the total horizontal flight distance provided by the above embodiment of the present invention, the total horizontal flight distance of each UAV is calculated: The process of the drone losing contact and returning to base: Implementation Method 1: After triggering the return-to-home procedure, each drone is controlled to fly from its initial return-to-home altitude at the same horizontal speed to directly above its respective landing position, and then descend to its respective landing position at the same vertical speed. Based on the known current coordinates, initial return-to-home altitude, and landing position of each drone, the climb altitude, total horizontal flight distance, and descent altitude for each drone's return can be obtained. In this implementation method, when the drones lost contact, the flight altitude of the four drones was 225 meters, which is less than the return-to-home reference altitude of 250 meters. Therefore, after triggering the return-to-home procedure, each drone must first climb to its respective initial return-to-home altitude, then fly at the same horizontal speed to directly above the ground target position, and then descend to its respective landing position at the same vertical speed. The specific return-to-home process for each drone is as follows: The first drone, when it lost contact, was flying at an altitude of 225 meters. It first climbed 25 meters to an altitude of 250 meters, then flew 1005.6 meters at a horizontal speed of 10 meters per second to reach its landing position, and then descended 250 meters at a vertical speed of 5 meters per second to the landing position.

[0049] The second drone, when it lost contact, was flying at an altitude of 225 meters. It first climbed 37.4 meters to an altitude of 262.4 meters, then flew 1006.8 meters at a horizontal speed of 10 meters per second to reach its landing position, and then descended at a vertical speed of 5 meters per second to an altitude of 262.4 meters to its landing position.

[0050] The third drone, when it lost contact, was flying at an altitude of 225 meters. It first climbed 47 meters to an altitude of 272 meters, then flew 1007.2 meters at a horizontal speed of 10 meters per second to reach its landing position, and then descended at a vertical speed of 5 meters per second to an altitude of 272 meters to its landing position.

[0051] The fourth drone, when it lost contact, was flying at an altitude of 225 meters. It first climbed 61 meters to an altitude of 286 meters, then flew 1008.4 meters at a horizontal speed of 10 meters per second to reach its landing position, and then descended at a vertical speed of 5 meters per second to an altitude of 286 meters to its landing position.

[0052] Based on the above calculations, we can know the initial return altitude, climb altitude, and total horizontal flight distance of each drone during the return process after losing contact. Therefore, we can calculate the total return flight distance for each drone (climb altitude + total horizontal flight distance + descent altitude): By combining the known horizontal and vertical velocities, the return time for each drone can be calculated (climb time + horizontal flight time + descent time): Given that the return speed of a drone after losing contact is set to 10 m / s horizontally and 5 m / s vertically, the relationship between the drone's flight distance and flight time is shown in Table 1 below.

[0053] Table 1 As shown in Implementation Method 1 and Table 1, when the UAV return-to-home control method provided in Implementation Method 1 is used to control the UAV return-to-home, the four UAVs return horizontally from initial return-to-home altitudes of 250 meters, 262.4 meters, 272 meters, and 286 meters respectively, based on the calculated initial return-to-home altitudes. After reaching their respective landing positions directly above them, they descend vertically to their respective landing positions. The total return flight distances of the four UAVs are approximately 1280.6 meters, 1306.6 meters, 1326.2 meters, and 1355.4 meters respectively, and the return-to-home times are approximately 155.56 seconds, 160.64 seconds, 164.52 seconds, and 170.24 seconds respectively. During the return-to-home process, each UAV returns along its own route, achieving time and spatial isolation, and preventing collisions or overlapping return-to-home routes.

[0054] Implementation method two differs from implementation method one in that, in this implementation method, each UAV is controlled to first fly at the same horizontal speed for its corresponding preset horizontal flight distance, and then descend in a straight line at the same oblique speed (i.e. oblique flight speed) according to a preset descent angle to its respective landing position.

[0055] In this embodiment, when the drones lost contact, the flight altitude of the four drones was 225 meters, which is less than the return-to-home reference altitude of 250 meters. Therefore, after triggering the return-to-home procedure, each drone needs to first climb to its respective initial return-to-home altitude, then fly at the same horizontal speed for its corresponding preset horizontal flight distance, and then descend at the same oblique speed (i.e., oblique flight speed) along a preset descent angle to its respective landing position. In this second embodiment, the climb altitude and descent altitude are the same as in the first embodiment, and the horizontal distance in this second embodiment is the same as the total horizontal flight distance L in the first embodiment. i In this embodiment, the step interval for the horizontal flight distance... With a target distance of 50 meters, the preset horizontal flight distance for each drone is calculated as follows: The remaining horizontal distance for each drone before its oblique flight (straight-line descent) is calculated as follows: The descent angles of each UAV flying obliquely (descending in a straight line at an angle) are calculated as follows: The distances traveled by each drone during its oblique flight (straight-line descent at an angle) are calculated as follows: The specific return process for each drone is as follows: The first drone, when it lost contact, was flying at an altitude of 225 meters. It first climbed 25 meters to an altitude of 250 meters, and then descended at an angle of 8 meters per second. Fly at an angle for 1036.2 meters to the landing position.

[0056] The second drone, when it lost contact, was flying at an altitude of 225 meters. It first climbed 37.4 meters to an altitude of 262.4 meters, then flew horizontally for 50 meters at a speed of 10 meters per second, and then descended at an angle of 8 meters per second. Fly at an angle of 992.1 meters to the landing position.

[0057] The third drone, when it lost contact, was flying at an altitude of 225 meters. It first climbed 47 meters to an altitude of 272 meters, then flew 100 meters horizontally at a speed of 10 meters per second, and then descended at an angle of 8 meters per second. Fly at an angle of 947.1 meters to the landing position.

[0058] The fourth drone, when it lost contact, was flying at an altitude of 225 meters. It first climbed 61 meters to an altitude of 286 meters, then flew 150 meters at a horizontal speed of 10 meters per second, and then descended at an angle of 8 meters per second. The aircraft flew at an angle of 904.8 meters to its landing position.

[0059] Based on the above calculations, we can know the initial return altitude, climb altitude, preset horizontal flight distance, and diagonal flight distance of each drone during the return process after losing contact. From this, we can calculate the total return flight distance of each drone (climb altitude + preset horizontal flight distance + diagonal flight distance): By combining the known horizontal, vertical, and diagonal velocities, the return flight time for each drone can be calculated (climb time + horizontal flight time + diagonal flight time): Given that the return speed of a drone after losing contact is set to 10 m / s horizontally, 5 m / s vertically, and 8 m / s diagonally, the relationship between the drone's flight distance and flight time is shown in Table 2 below.

[0060] Table 2 As shown in Implementation Method 2 and Table 2, when the UAV return-to-home control method provided in Implementation Method 2 is used to control the UAV return-to-home, the four UAVs return horizontally from initial return-to-home altitudes of 250 meters, 262.4 meters, 272 meters, and 286 meters respectively, based on the calculated initial return-to-home altitudes. After flying the preset horizontal flight distance, they descend to their respective landing positions along inclined straight lines at their respective descent angles. The total return flight distances of the four UAVs are approximately 1061.2 meters, 1079.5 meters, 1094.1 meters, and 1115.8 meters respectively, and the return-to-home times are approximately 134.53 seconds, 136.49 seconds, 137.79 seconds, and 140.30 seconds respectively. During the return-to-home process, each UAV returns along its own route, achieving time and spatial isolation. Furthermore, while achieving vertical layering, horizontal staggered peaks are also achieved, preventing collisions or overlapping return-to-home routes.

[0061] Compared to the return process in Implementation Method 1, which involves flying horizontally at the same speed to directly above each landing position and then descending vertically at the same speed to their respective landing positions, the return process in Implementation Method 2, while considering vertical layering, ensures horizontal staggering between drones, resulting in higher safety. Furthermore, the total return distance and return time of each drone are significantly shortened, the time difference between drones is significantly reduced, the consistency of return time is improved, and the return efficiency is enhanced.

[0062] An embodiment of the present invention also provides a drone return-to-home control device, which is applied in a multi-drone collaborative operation mode, in which multiple drones fly and operate in the air and are connected to each other. Figure 3 The diagram shows the configuration of the UAV return-to-home control device, which includes: The location information acquisition module 301 is used to acquire the current location information of each of the multiple drones in response to the return-to-home control signal; The three-dimensional distance determination module 302 is used to calculate the three-dimensional distance between the current position of each UAV and the target landing point based on the current position information; wherein, the target landing point is used to determine the landing position of each UAV. The sorting module 303 is used to sort multiple drones based on the aforementioned three-dimensional distance; The return-to-home parameter setting module 304 is used to set the initial return-to-home altitude and return-to-home speed of each UAV according to the above sorting results; The return-to-home control module 305 is used to control each UAV to return to its own initial return-to-home altitude and return-to-home speed.

[0063] The specific functions and operations of each module in the control device 300 have been described in detail in the implementation of the above-described UAV return-to-home control method, so their repeated description will be omitted here.

[0064] In embodiments of the present invention, an electronic device is also provided, including a memory, a processor, and executable instructions stored in the memory and executable on the processor. When the processor executes the executable instructions, it implements the control method as described in the above embodiments of the present invention. Figure 4 The diagram shown is a structural schematic of the electronic device 400 provided in this embodiment of the present invention. Figure 4 As shown, the electronic device 400 includes: one or more processors 401 and a memory 402; and computer-executable instructions stored in the memory 402, which, when executed by the processor 401, cause the processor 401 to perform the control method as described in the above embodiments. The processor 401 may be a central processing unit (CPU) or other processing unit with data processing capabilities and / or instruction execution capabilities, and can control other components in the electronic device to perform desired functions. The memory 402 may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. Volatile memory may include, for example, random access memory (RAM) and / or cache memory. Non-volatile memory may include, for example, read-only memory (ROM), hard disk, flash memory, etc. One or more computer program instructions may be stored on the computer-readable storage medium, and the processor 401 can execute the program instructions to implement the steps in the control method of the above embodiments of the present invention and / or other desired functions.

[0065] Embodiments of the present invention also provide a computer-readable storage medium storing computer-executable instructions thereon, which, when executed by a processor, implement the control method described in the above embodiments. The computer-readable storage medium may be any combination of one or more readable media. The readable medium may be a readable signal medium or a readable storage medium. The readable storage medium may, for example, include, but is not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatuses, or devices, or any combination thereof. More specific examples of readable storage media (a non-exhaustive list) include: electrical connections having one or more wires, portable disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing. It should be understood that the processor in embodiments of the present invention can be a central processing unit (CPU), which can also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor, etc.

[0066] In summary, the embodiments of the present invention relate to a method, device, electronic device, and storage medium for controlling the return-to-home of unmanned aerial vehicles (UAVs). The method includes: in response to a return-to-home control signal, acquiring the current position information of each UAV among multiple UAVs; calculating the three-dimensional distance between the current position of each UAV and the target landing point based on the current position information; wherein the target landing point is used to determine the landing position of each UAV; sorting the multiple UAVs based on the three-dimensional distance; setting the initial return-to-home altitude and return-to-home speed of each UAV according to the sorting result; and controlling each UAV to return to home according to its respective initial return-to-home altitude and return-to-home speed. The control method provided by the embodiments of the present invention employs a dynamic distance sorting mechanism, calculating and sorting the three-dimensional distances between the current positions of multiple UAVs and the target landing point, prioritizing the closest UAV for straight-line return-to-home, and allowing the furthest UAV to climb in layers before planning its path, thereby avoiding multiple UAVs simultaneously occupying the return-to-home channel and improving return-to-home efficiency. Simultaneously, combined with a height-layered anti-collision strategy, a vertical safety interval is constructed in a multi-UAV collaborative scenario by determining the reference altitude and utilizing height offset rules, greatly reducing the risk of collisions between UAVs in the horizontal and vertical directions of the return-to-home route.

[0067] It should be understood that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples; within the framework of the invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of one or more embodiments of the invention as described above, which are not provided in the details for the sake of brevity. The specific embodiments of the invention described above are merely illustrative or explanatory of the principles of the invention and do not constitute a limitation of the invention. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of the invention should be included within the protection scope of the invention. Furthermore, the appended claims are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

Claims

1. A method for controlling the return-to-home of a drone, applied in a multi-drone cooperative operation mode, characterized in that, In the multi-drone collaborative operation mode, multiple drones fly and operate in the air, and the multiple drones are connected in communication; the method includes: In response to the return-to-home control signal, the current position information of each of the multiple drones is obtained; Based on the current location information, the three-dimensional distance between the current position of each UAV and the target landing point is calculated; wherein, the target landing point is used to determine the landing position of each UAV. The multiple drones are sorted based on the three-dimensional distance; Based on the sorting results, set the initial return altitude and return speed for each UAV; Control each drone to return to its original altitude and speed.

2. The method according to claim 1, characterized in that, The multiple drones are sorted based on the three-dimensional distance, including: The multiple drones are sorted from smallest to largest based on the three-dimensional distance, and the multiple drones are sequentially designated as drone number 1, drone number 2, ..., drone number N; Where N represents the total number of drones.

3. The method according to claim 2, characterized in that, The initial return altitude for each drone is set according to the following formula: in, Let represent the initial return altitude of the i-th UAV, i = 1, 2, ..., N; N represents the total number of UAVs. The reference altitude is set as the maximum value among the current altitude of multiple UAVs, the preset return-to-home altitude, and the maximum waypoint altitude. This represents the dynamic altitude difference between the initial return altitude of each drone and the reference altitude. This dynamic altitude difference is related to the total number of drones and the remaining battery power of each drone.

4. The method according to claim 3, characterized in that, The dynamic height difference is set according to the following formula: in, This indicates the preset reference interval. This represents the remaining battery percentage of the i-th drone.

5. The method according to claim 3, characterized in that, Control each drone to return to its original altitude and speed, including: Determine whether the current altitude of multiple drones is equal to the reference altitude; When the current altitude of multiple drones is equal to the reference altitude, control the first drone to return from its current position, and control the second to Nth drones to rise to their respective dynamic altitude differences to reach their initial return altitudes before returning. When the current altitude of multiple drones is lower than the reference altitude, the first drone is controlled to rise to the reference altitude and then return to home. The second to Nth drones are controlled to rise to the reference altitude and then return to home when the sum of the differences between the reference altitude and their respective dynamic altitudes reaches their respective initial return altitudes.

6. The method according to any one of claims 1-5, characterized in that, Controlling each drone to return to its respective initial return altitude and return speed also includes: Control each drone to fly from its initial return altitude at the same horizontal speed to directly above its respective landing position, and then descend to its respective landing position at the same vertical speed; or, Each drone is controlled to fly from its initial return altitude at the same horizontal speed for its corresponding preset horizontal flight distance, and then descend in a straight line at the same oblique speed and its preset descent angle to its respective landing position.

7. The method according to any one of claims 1-5, characterized in that, The method further includes: Real-time acquisition of wireless signal strength between the UAV and the ground control station; When the wireless signal strength remains below the second signal strength threshold for a first threshold period of time, it is determined that the communication between the UAV and the ground control station is interrupted, and the return-to-home control signal is triggered.

8. A drone return-to-home control device, applied in a multi-drone cooperative operation mode, characterized in that, In the multi-drone collaborative operation mode, multiple drones fly and operate in the air, and the multiple drones are connected in communication; the device includes: The location information acquisition module is used to acquire the current location information of each of the multiple drones in response to the return-to-home control signal; A three-dimensional distance determination module is used to calculate the three-dimensional distance between the current position of each UAV and the target landing point based on the current position information; wherein, the target landing point is used to determine the landing position of each UAV. A sorting module is used to sort the multiple drones based on the three-dimensional distance; The return-to-home parameter setting module is used to set the initial return-to-home altitude and return-to-home speed of each UAV according to the sorting results; The return-to-home control module is used to control each drone to return to its own initial return-to-home altitude and speed.

9. An electronic device comprising a memory, a processor, and executable instructions stored in the memory and executable on the processor, characterized in that, When the processor executes the executable instructions, it implements the control method as described in any one of claims 1-7.

10. A computer-readable storage medium having computer-executable instructions stored thereon, characterized in that, When the executable instructions are executed by the processor, they implement the control method as described in any one of claims 1-7.

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