A control system for a drone landing on a mobile platform

Abstract

The present invention relates to the technical field of unmanned aerial vehicles (UAVs), and discloses a control system for a UAV to land on a mobile platform. The key points of the technical solution are as follows: the control platform first sends a return instruction to the UAV, and sends an environmental collection signal to the environmental collection module; the analysis module inputs the environmental information to generate a return route budget signal; the route planning module generates a return route and sends it to the UAV; the UAV starts to travel, sends an entry request signal to the route planning module, and sends an environmental scanning signal to the environmental collection module; the environment collection module collects the environmental information and sends it to the analysis module; the analysis module inputs the environmental information and generates an entry route signal; the route planning module generates an entry route and sends it to the UAV; the UAV feeds back its own position information to the analysis module; the adjustment module is used to issue a command to control the UAV to adjust the landing budget position.

Description

Technical Field

[0001] The present invention relates to the technical field of unmanned aerial vehicles (UAVs), and more particularly to a control system for a UAV to land on a mobile platform. Background Art

[0002] 1. Currently, RTK technology is used to complete landing.

[0003] 2. Currently, most precision landing technologies combine RTK positioning with vision guidance. RTK positioning is affected by the number of satellites searched and the stability of the RTK communication link; vision guidance is affected by environmental factors, such as the contrast between the guidance code and the background in strong and low light conditions outdoors, and the overlapping shadows cast by the drone during landing. These issues affect the safety and accuracy of drone landings.

[0004] 3. Laser guidance is also currently used. Generally, a drone is equipped with a laser radar, which is used to guide the drone to land safely through ranging and triangulation calculations. However, the accuracy of the laser radar is not easy to improve.

[0005] 4. Currently, ground-based positioning is also being used, such as UWB-assisted positioning (UWB positioning technology primarily uses the principle of time difference measurement to determine the transmitter's relative position by analyzing UWB signals received by multiple receivers. This method has high positioning accuracy and anti-interference capabilities and is widely used in indoor positioning, mobile device tracking and other fields.). In actual applications, UWB hardware itself has poor stability, mainly due to hardware failure caused by self-heating. At the same time, existing technologies are not easy to complete automatic correction and are not convenient for providing accurate values for precise landing. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a control system for a drone landing on a mobile platform, which is used to overcome the above-mentioned defects in the existing technology. The environment near the landing platform and the drone is collected and analyzed through the environment acquisition module, wherein image acquisition and laser point cloud acquisition are designed when collecting information, and then data processing and modeling are performed. When modeling, the collected point cloud coordinates and image information coordinates are compared in the same coordinate system, and the modeling is more realistic and reliable. At the same time, the interval segment is divided according to the modeled distance, and the speed of the drone is controlled in different interval segments when flying back, thereby improving the safety of the drone flight. The route planning module is used to formulate flight routes for different interval segments. The drone will transmit real-time position during flight. During the feedback process, the adjustment module enters to perform position comparison. When the drone deviates from the expected route at any node, the adjustment module will directly issue a new route flight mission to the drone, thereby avoiding delays in the drone's search for the route again after deviation.

[0007] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a control system for a UAV to land on a mobile platform, comprising a control platform, an environment collection module, an analysis module, a route planning module and an adjustment module; the control platform first sends a return instruction to the UAV, and sends an environment collection signal to the environment collection module, the analysis module enters the environment information to generate a return route budget signal, the route planning module generates a return route and sends it to the UAV, the UAV starts to travel, sends an entry request signal to the route planning module, and sends an environment scanning signal to the environment collection module, the environment collection module collects the environment information and sends it to the analysis module, the analysis module enters the environment information and generates an entry route signal, the route planning module generates an entry route and sends it to the UAV, the UAV feeds back its own position information to the analysis module, the adjustment module is used to issue a command to control the UAV to adjust the landing budget position, and bypasses the route planning module to directly send the control command, After the man-machine lands and sends a stop signal, the control platform determines that the drone landing mission is completed. The environment acquisition module is used to collect and analyze the environment near the landing platform and the drone. When collecting information, image acquisition and laser point cloud acquisition are designed, and then data processing and modeling are performed. When modeling, the collected point cloud coordinates and image information coordinates are compared in the same coordinate system, which makes the modeling more realistic and reliable. At the same time, the intervals are divided according to the modeled distance, and the speed of the drone is controlled in different intervals when flying back, thereby improving the safety of the drone flight. The route planning module is used to formulate flight routes for different intervals. The drone will transmit real-time position during flight, and the adjustment module will enter for position comparison during the feedback process. When the drone deviates from the expected route at any node, the adjustment module will directly issue a new route flight mission to the drone, thereby avoiding delays in the drone's search for the route again after deviation.

[0008] As a further improvement of the present invention, the adjustment module includes a landing route changing unit; the landing route changing unit has a built-in accounting threshold to check whether the difference between the actual position information of the drone and the standard position information is greater than the accounting threshold. When the accounting threshold is not exceeded, a landing signal is sent to the analysis module. The analysis module sends a landing route setting signal to the route setting module. The route setting module sends the customized landing route to the drone and the drone starts to land. During the landing process, the drone sends position information to the analysis module in real time. The analysis module analyzes whether the difference between the landing route and the actual position of the drone exceeds the accounting threshold. When the accounting threshold is exceeded, an adjustment signal is sent to the landing route changing unit. The landing route changing unit first sends a stop command to the drone. At the same time, the landing route changing unit sets a new landing route based on the current position of the drone, and then sends it to the drone, and sends a data group before and after the adjustment of the drone landing route to the control platform. The control platform sends a data analysis signal to the analysis module. The analysis module compares the difference between the real-time position coordinates of the drone and the predetermined coordinates in the data group.

[0009] As a further improvement of the present invention, the environment acquisition module includes a point cloud acquisition unit and a modeling unit; the point cloud acquisition unit generates three-dimensional coordinates of the points where the laser is reflected and then records them to generate a point cloud coordinate group; the modeling unit extracts image information of the surrounding environment to generate a three-dimensional model; the point cloud coordinate group of the cloud acquisition unit and the three-dimensional model values in the modeling unit are compared with each other to calculate the modeling accuracy

[0010] As a further improvement of the present invention, the analysis module includes a scene segmentation unit, a landing route budget unit, and a return route budget unit; the scene segmentation unit is used to segment the drone's flight section and generate a plan for specifying the drone's flight speed in different scenes during flight; the return route budget unit is used to generate a driving route draft in different scenes based on the different scenes obtained by the scene segmentation unit; the landing route budget unit is used to preliminarily prepare a landing draft for the drone when it lands

[0011] As a further improvement of the present invention, the route planning module includes an inbound route unit, a return route unit and a landing route unit; the return route unit is the route that the drone flies after receiving the return command; the inbound route unit is the section of the route that the drone travels after completing the distance specified by the return route unit; the landing route unit is the landing draft of the landing route budget unit after the drone completes the section of the inbound route unit.

[0012] As a further improvement of the present invention, the modeling unit includes an air modeling strategy and a ground modeling strategy; the air modeling strategy is that a laser beam group is emitted from the ground to the sky, and a first three-dimensional coordinate draft is recorded after refraction occurs; the ground modeling strategy is that a laser beam group is emitted from a drone to the ground, and a second three-dimensional coordinate draft is recorded after refraction occurs; the first three-dimensional coordinate draft and the second three-dimensional coordinate draft are fitted to each other in the same coordinate system to generate a modeling

[0013] As a further improvement of the present invention, the scene segmentation unit includes an obstacle zone strategy, a buffer zone strategy and a navigable zone strategy; the obstacle zone strategy is to reduce the flight speed of the drone, give the environment acquisition module sufficient time to collect environmental information, determine all obstacles that affect driving on the driving route, and generate a draft of the route to be traveled based on the location of the obstacles; the buffer zone strategy is to reduce the flight speed of the drone, give the environment acquisition module sufficient time to collect environmental information, complete modeling, and generate a preliminary plan for the route to be traveled based on the modeled environmental information; the navigable zone strategy is to increase the flight speed of the drone and reach the drone entry position as soon as possible

[0014] As a further improvement of the present invention, the landing route unit includes a route landing strategy; the route landing strategy is a number of flight segments, the flight segment is first vertical landing and then straight flight, each vertical landing distance gradually decreases, and the straight flight distance gradually decreases

[0015] As a further improvement of the present invention, the analysis module generates a coordinate curve graph, the horizontal axis is the frequency of errors exceeding the calculation threshold, and the vertical axis is the difference between the real-time position coordinates and the predetermined coordinates. The beneficial effects of the present invention are:

[0016] (1) The present invention collects and analyzes the environment near the landing platform and the drone through the environment acquisition module, wherein image acquisition and laser point cloud acquisition are designed when collecting information, and then data processing and modeling are performed. During modeling, the collected point cloud coordinates and image information coordinates are compared in the same coordinate system, so that the modeling is more realistic and reliable. At the same time, the intervals are divided according to the modeled distance, and the speed of the drone in different intervals when flying back is controlled, thereby improving the safety of the drone flight. The flight routes of different intervals are formulated in conjunction with the route formulation module. The drone will transmit real-time position during flight. During the feedback process, the adjustment module enters to perform position comparison. When the drone deviates from the expected route at any node, the adjustment module will directly issue a new route flight mission to the drone, thereby avoiding the delay problem of the drone re-finding the route after deviation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the system modules of the present invention;

[0018] Figure 2 It is a schematic diagram of the system flow of the present invention.

[0019] Figure 3 It is a schematic diagram of the landing route of the third specific embodiment of the present invention.

[0020] Figure numerals: 1. Control platform; 2. Environment acquisition module; 3. Analysis module; 4. Route planning module; 5. Adjustment module; 11. Cloud acquisition unit; 12. Modeling unit; 21. Scene segmentation unit; 22. Landing route budget unit; 23. Return route budget unit; 31. Inbound route unit; 32. Return route unit; 33. Landing route unit; 41. Landing route change unit.

[0021] Specific real-time method

[0022] The present invention will be further described in detail below with reference to the accompanying drawings and real-time examples. Identical components are denoted by the same reference numerals. It should be noted that the terms "front", "rear", "left", "right", "up", and "down" used in the following description refer to directions in the accompanying drawings, and the terms "bottom", "top", "inside", and "outside" refer to directions in the accompanying drawings, respectively.

[0023] The direction toward or away from the geometric center of a specific component.

[0024] Reference Figure 1-2 As shown, in this real-time example, a control system for a drone landing on a mobile platform includes a control platform 1, an environment acquisition module 2, an analysis module 3, a route setting module 4 and an adjustment module 5; the control platform 1 first sends a return instruction to the drone, and sends an environment acquisition signal to the environment acquisition module 2, the analysis module 3 enters the environment information to generate a return route budget signal, the route setting module 4 generates a return route and sends it to the drone, the drone starts to travel, sends an entry request signal to the route setting module 4, and sends an environment scanning signal to the environment acquisition module 2, the environment acquisition module 2 collects the environment information and sends it to the analysis module 3, the analysis module 3 enters the environment information and generates an entry route signal, the route setting module 4 generates an entry route and sends it to the drone, the drone feeds back its own position information to the analysis module 3, the adjustment module 5 is used to issue a command to control the drone to adjust the landing budget position, and bypasses the route setting module 4 to directly send a control command. After the drone lands and sends a stop signal, the control platform 1 determines that the drone landing mission is completed.

[0025] Reference Figure 1-2As shown, the adjustment module 5 includes a landing route changing unit 41; the landing route changing unit 41 has a built-in accounting threshold, and checks whether the difference between the actual position information of the drone and the standard position information is greater than the accounting threshold. When it does not exceed the accounting threshold, a landing signal is sent to the analysis module 3, and the analysis module 3 sends a landing route setting signal to the route setting module 4. The route setting module 4 sends the customized landing route to the drone, and the drone starts to land. During the landing process, the drone sends position information to the analysis module 3 in real time. The analysis module 3 analyzes whether the difference between the landing route and the actual position of the drone exceeds the accounting threshold. When it exceeds the accounting threshold, an adjustment signal is sent to the landing route changing unit 41. The landing route changing unit 41 first sends a stop command to the drone. At the same time, the landing route changing unit 41 formulates a new landing route based on the current position of the drone, and then sends it to the drone, and sends a data group before and after the adjustment of the drone landing route to the control platform 1. The control platform 1 sends a data analysis signal to the analysis module 3. The analysis module 3 compares the difference between the real-time position coordinates of the drone and the predetermined coordinates in the data group.

[0026] Reference Figure 1-2 As shown, the environment acquisition module 2 includes a point cloud acquisition unit 11 and a modeling unit 12; the point cloud acquisition unit 11 generates three-dimensional coordinates of the points where the laser is reflected and then records them to generate a point cloud coordinate group; the modeling unit 12 extracts image information of the surrounding environment and generates a three-dimensional model; the point cloud coordinate group of the cloud acquisition unit 11 and the three-dimensional model values in the modeling unit 12 are compared with each other to calculate the modeling accuracy.

[0027] Reference Figure 1-2 As shown, the analysis module 3 includes a scene segmentation unit 21, a landing route budget unit 22, and a return route budget unit 23; the scene segmentation unit 21 is used to segment the route section of the drone's flight and generate a plan for specifying the flight speed of the drone in different scenes during flight; the return route budget unit 23 is used to generate a driving route draft in different scenes based on the different scenes obtained by the scene segmentation unit 21; the landing route budget unit 22 is used to preliminarily prepare a landing draft when the drone lands.

[0028] Reference Figure 1-2 As shown, the route planning module 4 includes an inbound route unit 31, a return route unit 32 and a landing route unit 33; the return route unit 32 is the route that the UAV flies after receiving the return command; the inbound route unit 31 is the section of the road that the UAV travels after completing the distance specified by the return route unit 32; the landing route unit 33 is the landing draft of the landing route budget unit 22 that is activated after the UAV completes the section of the inbound route unit 31.

[0029] Reference Figure 1-2As shown, the modeling unit 12 includes an air modeling strategy and a ground modeling strategy; the air modeling strategy is that a laser beam group is emitted from the ground to the sky, and a first three-dimensional coordinate draft is recorded after refraction occurs; the ground modeling strategy is that a laser beam group is emitted from the drone to the ground, and a second three-dimensional coordinate draft is recorded after refraction occurs; the first three-dimensional coordinate draft and the second three-dimensional coordinate draft are fitted to each other in the same coordinate system to generate a modeling

[0030] Reference Figure 1-2 As shown, the scene segmentation unit 21 includes an obstacle zone strategy, a buffer zone strategy and a navigable zone strategy; the obstacle zone strategy is to reduce the flight speed of the drone, give the environment acquisition module 2 sufficient time to collect environmental information, determine all obstacles that affect driving on the driving route, and generate a draft route to be driven according to the location of the obstacles; the buffer zone strategy is to reduce the flight speed of the drone, give the environment acquisition module 2 sufficient time to collect environmental information, complete modeling, and generate a preliminary route plan to be driven according to the modeled environmental information; the navigable zone strategy is to increase the flight speed of the drone and reach the drone entry position as soon as possible

[0031] Reference Figure 1-2 As shown, the landing route unit 33 includes a route landing strategy; the route landing strategy is a number of flight segments, the flight segment is first vertical landing and then straight flight, each vertical landing distance gradually decreases, and the straight flight distance gradually decreases

[0032] Reference Figure 1-2 As shown, the analysis module 3 generates a coordinate curve graph, the horizontal axis is the frequency of errors exceeding the calculation threshold, and the vertical axis is the difference between the real-time position coordinate and the predetermined coordinate.

[0033] Working principle: Refer to Figure 1-2 As shown,

[0034] The control platform 1 first sends a return command to the UAV, and sends a standby command at a specific location to the landing platform. The landing platform starts to drive to the specific location to wait for the UAV. After receiving the return command, the UAV first feeds back its own position signal to the analysis module 3. The analysis module 3 sends an environment collection signal to the environment collection module 2. The environment collection module 2 feeds back the collected environment information. The analysis module 3 enters the environment information to generate a return route budget signal and gives it to the route planning module 4. The route planning module 4 generates a return route and sends it to the UAV. The UAV starts to drive and sends an entry request signal to the route planning module 4 before reaching the end position of the return route, and sends an environment scanning signal to the environment collection module 2. The environment collection module 2 collects the environment information and sends it to the analysis module 3. The analysis module 3 enters the environment information and generates an entry route signal. The route planning module 4 generates an entry route and sends it to the UAV. The UAV feeds back its own position information to the analysis module 3 to the adjustment module 5. The adjustment module 5 has a built-in accounting threshold to check whether the difference between the actual position information and the standard position information is greater than the accounting threshold. If it does not exceed the threshold, it sends The control platform 1 sends a data group of the drone's landing route before and after the adjustment to the control platform 1. The control platform 1 sends a data analysis signal to the analysis module 3. The analysis module 3 compares the difference between the real-time position coordinates of the drone and the predetermined coordinates in the data group and generates a coordinate curve graph. The drone starts landing according to the new landing route, with the horizontal axis representing the frequency of errors exceeding the calculation threshold and the vertical axis representing the difference. The drone starts landing in this way, and repeats this process until the landing is completed. After the drone sends a stop signal, the control platform 1 determines that the drone landing mission is complete.

[0035] For example, when the actual landing position of the UAV is at position A (X1, Y1, Z1), and the preset landing route position is position B (X2, Y2, Z2), the position difference calculation is performed to obtain (X1-X2, Y1-Y2, Z1-Z2), which are compared with the safety threshold respectively. When any value exceeds the safety threshold, the landing route changing unit 41 updates the landing route based on the position A (X1, Y1, Z1) to the landing platform position, and compensates for the next landing section until all the coordinate positions of the unlanded section of the new landing route and the unlanded section of the old route are the same, and then the UAV lands on the mobile platform.

[0036] Specific embodiment 2: Different from specific embodiment 1, the landing platform can move. When the UAV lands, the landing route change unit 41 will send a movement signal to the landing platform. The mobile platform moves according to the coordinates contained in the movement signal, thereby completing the complementation of the numerical deviation during the landing process of the UAV. While the landing platform completes the movement signal, the UAV remains in its original position.

[0037] Specific embodiment three: Different from the specific embodiment, the route landing strategy is spiral curve landing, and the virtual landing route is a straight line perpendicular to the landing platform.

[0038] The above is merely a preferred real-time implementation of the present invention. The scope of protection of the present invention is not limited to the above real-time implementation. All technical solutions based on the principles of the present invention are within the scope of protection of the present invention. It should be noted that improvements and modifications that do not depart from the principles of the present invention are within the scope of protection of the present invention.

Claims

1. A control system for a drone landing on a mobile platform, characterized by: It includes a control platform (1), an environment acquisition module (2), an analysis module (3), a route setting module (4) and an adjustment module (5); The control platform (1) first sends a return command to the UAV and sends an environmental acquisition signal to the environmental acquisition module (2). The analysis module (3) records the environmental information and generates a return route budget signal. The route setting module (4) generates a return route and sends it to the UAV. The UAV starts to travel and sends an entry request signal to the route setting module (4) and an environmental scanning signal to the environmental acquisition module (2). The environmental acquisition module (2) collects the environmental information and sends it to the analysis module (3). The analysis module (3) records the environmental information and generates an entry route signal. The route setting module (4) generates an entry route and sends it to the UAV. The UAV feeds back its own position information to the analysis module (3). The adjustment module (5) is used to send a command to control the UAV to adjust the landing budget position and directly send the control command by bypassing the route setting module (4). After the UAV lands and sends a stop signal, the control platform (1) determines that the UAV landing mission is completed. The route planning module (4) includes an inbound route unit (31), a return route unit (32) and a landing route unit (33); The return route unit (32) is the route that the UAV flies after receiving the return command; The inbound route unit (31) is the section of the road that the UAV travels after completing the distance specified by the return route unit (32); The landing route unit (33) is a landing draft of the landing route budget unit (22) after the UAV completes the route section of the inbound route unit (31); The landing route unit (33) includes a route landing strategy; The route landing strategy comprises several flight segments, wherein the flight segment is first a vertical landing and then a straight-line flight, and each vertical landing distance gradually decreases, and the straight-line flight distance gradually decreases.

2. A control system for landing a drone on a mobile platform according to claim 1, characterized in that: The adjustment module (5) includes a landing route changing unit (41); The landing route changing unit (41) has a built-in calculation threshold value, and checks whether the difference between the actual position information of the drone and the standard position information is greater than the calculation threshold value. When the difference does not exceed the calculation threshold value, a landing signal is sent to the analysis module (3). The analysis module (3) sends a landing route setting signal to the route setting module (4). The route setting module (4) sends the customized landing route to the drone, and the drone starts to land. During the landing process, the drone sends position information to the analysis module (3) in real time. The analysis module (3) analyzes whether the difference between the landing route and the actual position of the drone exceeds the calculation threshold value. When the difference exceeds the calculation threshold value, an adjustment signal is sent to the landing route changing unit (41). The landing route changing unit (41) first sends a stop command to the drone, and at the same time, the landing route changing unit (41) formulates a new landing route based on the current position of the drone, and then sends it to the drone, and sends a data group before and after the adjustment of the drone landing route to the control platform (1). The control platform (1) sends a data analysis signal to the analysis module (3). The analysis module (3) compares the difference between the real-time position coordinates of the drone and the predetermined coordinates in the data group.

3. The control system for landing a drone on a mobile platform according to claim 2, characterized in that: The environment acquisition module (2) includes a point cloud acquisition unit (11) and a modeling unit (12); The point cloud acquisition unit (11) generates three-dimensional coordinates of the points where the laser is reflected and then records them to generate a point cloud coordinate group; The modeling unit (12) extracts image information of the surrounding environment and generates a three-dimensional model; The point cloud coordinate group of the cloud acquisition unit (11) and the three-dimensional model values in the modeling unit (12) are compared with each other to calculate the modeling accuracy.

4. The control system for landing a drone on a mobile platform according to claim 2, characterized in that: The analysis module (3) includes a scene segmentation unit (21), a landing route estimation unit (22), and a return route estimation unit (23); The scene segmentation unit (21) is used to segment the route of the UAV and generate a plan for specifying the flight speed of the UAV in different scenes during flight. The return route budget unit (23) generates draft driving routes within different scenarios based on the different scenarios obtained by the scenario segmentation unit (21); The landing route budget unit (22) prepares a preliminary landing draft for the UAV when landing.

5. The control system for landing a drone on a mobile platform according to claim 3, characterized in that: The modeling unit (12) includes an air modeling strategy and a ground modeling strategy; The air modeling strategy is to send a group of laser beams from the ground to the sky, and record the first three-dimensional coordinate draft after refraction occurs; The ground modeling strategy is that a laser beam group is emitted from the UAV to the ground, and a second three-dimensional coordinate draft is recorded after refraction occurs; The first three-dimensional coordinate draft and the second three-dimensional coordinate draft are fitted to each other in the same coordinate system to generate a model.

6. The control system for landing a UAV on a mobile platform according to claim 4, characterized in that: The scene segmentation unit (21) includes an obstacle area strategy, a buffer area strategy and a navigation area strategy; The obstacle zone strategy is to reduce the flight speed of the UAV, giving the environment acquisition module (2) sufficient time to collect environmental information, identify all obstacles that affect the driving route, and generate a draft route to be driven based on the location of the obstacles; The buffer zone strategy is to reduce the flight speed of the UAV, giving the environment acquisition module (2) sufficient time to collect environmental information, complete modeling, and generate an initial plan of the route to be traveled based on the modeled environmental information; The airworthy zone strategy is to increase the flight speed of the UAV and reach the UAV entry position as quickly as possible.

7. The control system for landing a UAV on a mobile platform according to claim 3, characterized in that: The analysis module (3) generates a coordinate curve graph, wherein the horizontal axis represents the frequency of errors exceeding the calculation threshold, and the vertical axis represents the difference between the real-time position coordinate and the predetermined coordinate.

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